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5338 lines
133 KiB
5338 lines
133 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2010-2011 Canonical Ltd <[email protected]> |
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* Copyright (C) 2011-2012 Linaro Ltd <[email protected]> |
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* |
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* Standard functionality for the common clock API. See Documentation/driver-api/clk.rst |
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*/ |
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|
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#include <linux/clk.h> |
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#include <linux/clk-provider.h> |
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#include <linux/clk/clk-conf.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/spinlock.h> |
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#include <linux/err.h> |
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#include <linux/list.h> |
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#include <linux/slab.h> |
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#include <linux/of.h> |
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#include <linux/device.h> |
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#include <linux/init.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/sched.h> |
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#include <linux/clkdev.h> |
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|
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#include "clk.h" |
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|
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static DEFINE_SPINLOCK(enable_lock); |
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static DEFINE_MUTEX(prepare_lock); |
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|
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static struct task_struct *prepare_owner; |
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static struct task_struct *enable_owner; |
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|
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static int prepare_refcnt; |
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static int enable_refcnt; |
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|
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static HLIST_HEAD(clk_root_list); |
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static HLIST_HEAD(clk_orphan_list); |
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static LIST_HEAD(clk_notifier_list); |
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|
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static const struct hlist_head *all_lists[] = { |
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&clk_root_list, |
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&clk_orphan_list, |
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NULL, |
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}; |
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|
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/*** private data structures ***/ |
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|
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struct clk_parent_map { |
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const struct clk_hw *hw; |
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struct clk_core *core; |
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const char *fw_name; |
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const char *name; |
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int index; |
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}; |
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|
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struct clk_core { |
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const char *name; |
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const struct clk_ops *ops; |
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struct clk_hw *hw; |
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struct module *owner; |
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struct device *dev; |
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struct device_node *of_node; |
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struct clk_core *parent; |
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struct clk_parent_map *parents; |
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u8 num_parents; |
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u8 new_parent_index; |
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unsigned long rate; |
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unsigned long req_rate; |
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unsigned long new_rate; |
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struct clk_core *new_parent; |
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struct clk_core *new_child; |
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unsigned long flags; |
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bool orphan; |
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bool rpm_enabled; |
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unsigned int enable_count; |
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unsigned int prepare_count; |
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unsigned int protect_count; |
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unsigned long min_rate; |
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unsigned long max_rate; |
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unsigned long accuracy; |
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int phase; |
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struct clk_duty duty; |
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struct hlist_head children; |
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struct hlist_node child_node; |
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struct hlist_head clks; |
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unsigned int notifier_count; |
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#ifdef CONFIG_DEBUG_FS |
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struct dentry *dentry; |
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struct hlist_node debug_node; |
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#endif |
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struct kref ref; |
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}; |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/clk.h> |
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|
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struct clk { |
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struct clk_core *core; |
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struct device *dev; |
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const char *dev_id; |
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const char *con_id; |
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unsigned long min_rate; |
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unsigned long max_rate; |
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unsigned int exclusive_count; |
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struct hlist_node clks_node; |
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}; |
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|
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/*** runtime pm ***/ |
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static int clk_pm_runtime_get(struct clk_core *core) |
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{ |
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if (!core->rpm_enabled) |
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return 0; |
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|
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return pm_runtime_resume_and_get(core->dev); |
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} |
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|
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static void clk_pm_runtime_put(struct clk_core *core) |
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{ |
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if (!core->rpm_enabled) |
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return; |
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|
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pm_runtime_put_sync(core->dev); |
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} |
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|
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/*** locking ***/ |
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static void clk_prepare_lock(void) |
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{ |
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if (!mutex_trylock(&prepare_lock)) { |
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if (prepare_owner == current) { |
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prepare_refcnt++; |
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return; |
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} |
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mutex_lock(&prepare_lock); |
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} |
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WARN_ON_ONCE(prepare_owner != NULL); |
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WARN_ON_ONCE(prepare_refcnt != 0); |
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prepare_owner = current; |
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prepare_refcnt = 1; |
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} |
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|
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static void clk_prepare_unlock(void) |
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{ |
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WARN_ON_ONCE(prepare_owner != current); |
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WARN_ON_ONCE(prepare_refcnt == 0); |
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if (--prepare_refcnt) |
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return; |
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prepare_owner = NULL; |
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mutex_unlock(&prepare_lock); |
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} |
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|
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static unsigned long clk_enable_lock(void) |
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__acquires(enable_lock) |
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{ |
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unsigned long flags; |
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|
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/* |
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* On UP systems, spin_trylock_irqsave() always returns true, even if |
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* we already hold the lock. So, in that case, we rely only on |
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* reference counting. |
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*/ |
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if (!IS_ENABLED(CONFIG_SMP) || |
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!spin_trylock_irqsave(&enable_lock, flags)) { |
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if (enable_owner == current) { |
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enable_refcnt++; |
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__acquire(enable_lock); |
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if (!IS_ENABLED(CONFIG_SMP)) |
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local_save_flags(flags); |
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return flags; |
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} |
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spin_lock_irqsave(&enable_lock, flags); |
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} |
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WARN_ON_ONCE(enable_owner != NULL); |
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WARN_ON_ONCE(enable_refcnt != 0); |
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enable_owner = current; |
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enable_refcnt = 1; |
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return flags; |
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} |
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|
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static void clk_enable_unlock(unsigned long flags) |
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__releases(enable_lock) |
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{ |
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WARN_ON_ONCE(enable_owner != current); |
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WARN_ON_ONCE(enable_refcnt == 0); |
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|
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if (--enable_refcnt) { |
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__release(enable_lock); |
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return; |
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} |
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enable_owner = NULL; |
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spin_unlock_irqrestore(&enable_lock, flags); |
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} |
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static bool clk_core_rate_is_protected(struct clk_core *core) |
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{ |
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return core->protect_count; |
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} |
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|
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static bool clk_core_is_prepared(struct clk_core *core) |
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{ |
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bool ret = false; |
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|
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/* |
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* .is_prepared is optional for clocks that can prepare |
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* fall back to software usage counter if it is missing |
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*/ |
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if (!core->ops->is_prepared) |
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return core->prepare_count; |
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|
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if (!clk_pm_runtime_get(core)) { |
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ret = core->ops->is_prepared(core->hw); |
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clk_pm_runtime_put(core); |
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} |
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|
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return ret; |
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} |
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static bool clk_core_is_enabled(struct clk_core *core) |
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{ |
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bool ret = false; |
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|
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/* |
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* .is_enabled is only mandatory for clocks that gate |
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* fall back to software usage counter if .is_enabled is missing |
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*/ |
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if (!core->ops->is_enabled) |
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return core->enable_count; |
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|
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/* |
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* Check if clock controller's device is runtime active before |
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* calling .is_enabled callback. If not, assume that clock is |
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* disabled, because we might be called from atomic context, from |
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* which pm_runtime_get() is not allowed. |
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* This function is called mainly from clk_disable_unused_subtree, |
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* which ensures proper runtime pm activation of controller before |
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* taking enable spinlock, but the below check is needed if one tries |
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* to call it from other places. |
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*/ |
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if (core->rpm_enabled) { |
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pm_runtime_get_noresume(core->dev); |
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if (!pm_runtime_active(core->dev)) { |
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ret = false; |
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goto done; |
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} |
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} |
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ret = core->ops->is_enabled(core->hw); |
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done: |
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if (core->rpm_enabled) |
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pm_runtime_put(core->dev); |
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|
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return ret; |
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} |
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/*** helper functions ***/ |
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|
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const char *__clk_get_name(const struct clk *clk) |
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{ |
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return !clk ? NULL : clk->core->name; |
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} |
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EXPORT_SYMBOL_GPL(__clk_get_name); |
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|
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const char *clk_hw_get_name(const struct clk_hw *hw) |
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{ |
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return hw->core->name; |
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} |
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EXPORT_SYMBOL_GPL(clk_hw_get_name); |
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|
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struct clk_hw *__clk_get_hw(struct clk *clk) |
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{ |
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return !clk ? NULL : clk->core->hw; |
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} |
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EXPORT_SYMBOL_GPL(__clk_get_hw); |
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unsigned int clk_hw_get_num_parents(const struct clk_hw *hw) |
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{ |
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return hw->core->num_parents; |
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} |
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EXPORT_SYMBOL_GPL(clk_hw_get_num_parents); |
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|
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struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw) |
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{ |
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return hw->core->parent ? hw->core->parent->hw : NULL; |
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} |
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EXPORT_SYMBOL_GPL(clk_hw_get_parent); |
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static struct clk_core *__clk_lookup_subtree(const char *name, |
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struct clk_core *core) |
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{ |
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struct clk_core *child; |
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struct clk_core *ret; |
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|
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if (!strcmp(core->name, name)) |
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return core; |
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hlist_for_each_entry(child, &core->children, child_node) { |
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ret = __clk_lookup_subtree(name, child); |
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if (ret) |
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return ret; |
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} |
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|
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return NULL; |
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} |
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static struct clk_core *clk_core_lookup(const char *name) |
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{ |
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struct clk_core *root_clk; |
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struct clk_core *ret; |
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|
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if (!name) |
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return NULL; |
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|
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/* search the 'proper' clk tree first */ |
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hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
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ret = __clk_lookup_subtree(name, root_clk); |
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if (ret) |
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return ret; |
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} |
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|
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/* if not found, then search the orphan tree */ |
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hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
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ret = __clk_lookup_subtree(name, root_clk); |
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if (ret) |
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return ret; |
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} |
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return NULL; |
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} |
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#ifdef CONFIG_OF |
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static int of_parse_clkspec(const struct device_node *np, int index, |
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const char *name, struct of_phandle_args *out_args); |
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static struct clk_hw * |
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of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec); |
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#else |
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static inline int of_parse_clkspec(const struct device_node *np, int index, |
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const char *name, |
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struct of_phandle_args *out_args) |
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{ |
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return -ENOENT; |
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} |
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static inline struct clk_hw * |
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of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) |
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{ |
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return ERR_PTR(-ENOENT); |
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} |
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#endif |
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|
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/** |
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* clk_core_get - Find the clk_core parent of a clk |
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* @core: clk to find parent of |
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* @p_index: parent index to search for |
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* |
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* This is the preferred method for clk providers to find the parent of a |
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* clk when that parent is external to the clk controller. The parent_names |
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* array is indexed and treated as a local name matching a string in the device |
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* node's 'clock-names' property or as the 'con_id' matching the device's |
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* dev_name() in a clk_lookup. This allows clk providers to use their own |
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* namespace instead of looking for a globally unique parent string. |
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* |
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* For example the following DT snippet would allow a clock registered by the |
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* clock-controller@c001 that has a clk_init_data::parent_data array |
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* with 'xtal' in the 'name' member to find the clock provided by the |
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* clock-controller@f00abcd without needing to get the globally unique name of |
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* the xtal clk. |
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* |
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* parent: clock-controller@f00abcd { |
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* reg = <0xf00abcd 0xabcd>; |
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* #clock-cells = <0>; |
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* }; |
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* |
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* clock-controller@c001 { |
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* reg = <0xc001 0xf00d>; |
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* clocks = <&parent>; |
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* clock-names = "xtal"; |
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* #clock-cells = <1>; |
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* }; |
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* |
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* Returns: -ENOENT when the provider can't be found or the clk doesn't |
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* exist in the provider or the name can't be found in the DT node or |
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* in a clkdev lookup. NULL when the provider knows about the clk but it |
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* isn't provided on this system. |
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* A valid clk_core pointer when the clk can be found in the provider. |
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*/ |
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static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index) |
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{ |
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const char *name = core->parents[p_index].fw_name; |
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int index = core->parents[p_index].index; |
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struct clk_hw *hw = ERR_PTR(-ENOENT); |
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struct device *dev = core->dev; |
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const char *dev_id = dev ? dev_name(dev) : NULL; |
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struct device_node *np = core->of_node; |
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struct of_phandle_args clkspec; |
|
|
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if (np && (name || index >= 0) && |
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!of_parse_clkspec(np, index, name, &clkspec)) { |
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hw = of_clk_get_hw_from_clkspec(&clkspec); |
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of_node_put(clkspec.np); |
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} else if (name) { |
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/* |
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* If the DT search above couldn't find the provider fallback to |
|
* looking up via clkdev based clk_lookups. |
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*/ |
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hw = clk_find_hw(dev_id, name); |
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} |
|
|
|
if (IS_ERR(hw)) |
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return ERR_CAST(hw); |
|
|
|
return hw->core; |
|
} |
|
|
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static void clk_core_fill_parent_index(struct clk_core *core, u8 index) |
|
{ |
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struct clk_parent_map *entry = &core->parents[index]; |
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struct clk_core *parent; |
|
|
|
if (entry->hw) { |
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parent = entry->hw->core; |
|
} else { |
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parent = clk_core_get(core, index); |
|
if (PTR_ERR(parent) == -ENOENT && entry->name) |
|
parent = clk_core_lookup(entry->name); |
|
} |
|
|
|
/* |
|
* We have a direct reference but it isn't registered yet? |
|
* Orphan it and let clk_reparent() update the orphan status |
|
* when the parent is registered. |
|
*/ |
|
if (!parent) |
|
parent = ERR_PTR(-EPROBE_DEFER); |
|
|
|
/* Only cache it if it's not an error */ |
|
if (!IS_ERR(parent)) |
|
entry->core = parent; |
|
} |
|
|
|
static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, |
|
u8 index) |
|
{ |
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if (!core || index >= core->num_parents || !core->parents) |
|
return NULL; |
|
|
|
if (!core->parents[index].core) |
|
clk_core_fill_parent_index(core, index); |
|
|
|
return core->parents[index].core; |
|
} |
|
|
|
struct clk_hw * |
|
clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index) |
|
{ |
|
struct clk_core *parent; |
|
|
|
parent = clk_core_get_parent_by_index(hw->core, index); |
|
|
|
return !parent ? NULL : parent->hw; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index); |
|
|
|
unsigned int __clk_get_enable_count(struct clk *clk) |
|
{ |
|
return !clk ? 0 : clk->core->enable_count; |
|
} |
|
|
|
static unsigned long clk_core_get_rate_nolock(struct clk_core *core) |
|
{ |
|
if (!core) |
|
return 0; |
|
|
|
if (!core->num_parents || core->parent) |
|
return core->rate; |
|
|
|
/* |
|
* Clk must have a parent because num_parents > 0 but the parent isn't |
|
* known yet. Best to return 0 as the rate of this clk until we can |
|
* properly recalc the rate based on the parent's rate. |
|
*/ |
|
return 0; |
|
} |
|
|
|
unsigned long clk_hw_get_rate(const struct clk_hw *hw) |
|
{ |
|
return clk_core_get_rate_nolock(hw->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_get_rate); |
|
|
|
static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core) |
|
{ |
|
if (!core) |
|
return 0; |
|
|
|
return core->accuracy; |
|
} |
|
|
|
unsigned long clk_hw_get_flags(const struct clk_hw *hw) |
|
{ |
|
return hw->core->flags; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_get_flags); |
|
|
|
bool clk_hw_is_prepared(const struct clk_hw *hw) |
|
{ |
|
return clk_core_is_prepared(hw->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_is_prepared); |
|
|
|
bool clk_hw_rate_is_protected(const struct clk_hw *hw) |
|
{ |
|
return clk_core_rate_is_protected(hw->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected); |
|
|
|
bool clk_hw_is_enabled(const struct clk_hw *hw) |
|
{ |
|
return clk_core_is_enabled(hw->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_is_enabled); |
|
|
|
bool __clk_is_enabled(struct clk *clk) |
|
{ |
|
if (!clk) |
|
return false; |
|
|
|
return clk_core_is_enabled(clk->core); |
|
} |
|
EXPORT_SYMBOL_GPL(__clk_is_enabled); |
|
|
|
static bool mux_is_better_rate(unsigned long rate, unsigned long now, |
|
unsigned long best, unsigned long flags) |
|
{ |
|
if (flags & CLK_MUX_ROUND_CLOSEST) |
|
return abs(now - rate) < abs(best - rate); |
|
|
|
return now <= rate && now > best; |
|
} |
|
|
|
static void clk_core_init_rate_req(struct clk_core * const core, |
|
struct clk_rate_request *req, |
|
unsigned long rate); |
|
|
|
static int clk_core_round_rate_nolock(struct clk_core *core, |
|
struct clk_rate_request *req); |
|
|
|
static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent) |
|
{ |
|
struct clk_core *tmp; |
|
unsigned int i; |
|
|
|
/* Optimize for the case where the parent is already the parent. */ |
|
if (core->parent == parent) |
|
return true; |
|
|
|
for (i = 0; i < core->num_parents; i++) { |
|
tmp = clk_core_get_parent_by_index(core, i); |
|
if (!tmp) |
|
continue; |
|
|
|
if (tmp == parent) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static void |
|
clk_core_forward_rate_req(struct clk_core *core, |
|
const struct clk_rate_request *old_req, |
|
struct clk_core *parent, |
|
struct clk_rate_request *req, |
|
unsigned long parent_rate) |
|
{ |
|
if (WARN_ON(!clk_core_has_parent(core, parent))) |
|
return; |
|
|
|
clk_core_init_rate_req(parent, req, parent_rate); |
|
|
|
if (req->min_rate < old_req->min_rate) |
|
req->min_rate = old_req->min_rate; |
|
|
|
if (req->max_rate > old_req->max_rate) |
|
req->max_rate = old_req->max_rate; |
|
} |
|
|
|
int clk_mux_determine_rate_flags(struct clk_hw *hw, |
|
struct clk_rate_request *req, |
|
unsigned long flags) |
|
{ |
|
struct clk_core *core = hw->core, *parent, *best_parent = NULL; |
|
int i, num_parents, ret; |
|
unsigned long best = 0; |
|
|
|
/* if NO_REPARENT flag set, pass through to current parent */ |
|
if (core->flags & CLK_SET_RATE_NO_REPARENT) { |
|
parent = core->parent; |
|
if (core->flags & CLK_SET_RATE_PARENT) { |
|
struct clk_rate_request parent_req; |
|
|
|
if (!parent) { |
|
req->rate = 0; |
|
return 0; |
|
} |
|
|
|
clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate); |
|
ret = clk_core_round_rate_nolock(parent, &parent_req); |
|
if (ret) |
|
return ret; |
|
|
|
best = parent_req.rate; |
|
} else if (parent) { |
|
best = clk_core_get_rate_nolock(parent); |
|
} else { |
|
best = clk_core_get_rate_nolock(core); |
|
} |
|
|
|
goto out; |
|
} |
|
|
|
/* find the parent that can provide the fastest rate <= rate */ |
|
num_parents = core->num_parents; |
|
for (i = 0; i < num_parents; i++) { |
|
unsigned long parent_rate; |
|
|
|
parent = clk_core_get_parent_by_index(core, i); |
|
if (!parent) |
|
continue; |
|
|
|
if (core->flags & CLK_SET_RATE_PARENT) { |
|
struct clk_rate_request parent_req; |
|
|
|
clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate); |
|
ret = clk_core_round_rate_nolock(parent, &parent_req); |
|
if (ret) |
|
continue; |
|
|
|
parent_rate = parent_req.rate; |
|
} else { |
|
parent_rate = clk_core_get_rate_nolock(parent); |
|
} |
|
|
|
if (mux_is_better_rate(req->rate, parent_rate, |
|
best, flags)) { |
|
best_parent = parent; |
|
best = parent_rate; |
|
} |
|
} |
|
|
|
if (!best_parent) |
|
return -EINVAL; |
|
|
|
out: |
|
if (best_parent) |
|
req->best_parent_hw = best_parent->hw; |
|
req->best_parent_rate = best; |
|
req->rate = best; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags); |
|
|
|
struct clk *__clk_lookup(const char *name) |
|
{ |
|
struct clk_core *core = clk_core_lookup(name); |
|
|
|
return !core ? NULL : core->hw->clk; |
|
} |
|
|
|
static void clk_core_get_boundaries(struct clk_core *core, |
|
unsigned long *min_rate, |
|
unsigned long *max_rate) |
|
{ |
|
struct clk *clk_user; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
*min_rate = core->min_rate; |
|
*max_rate = core->max_rate; |
|
|
|
hlist_for_each_entry(clk_user, &core->clks, clks_node) |
|
*min_rate = max(*min_rate, clk_user->min_rate); |
|
|
|
hlist_for_each_entry(clk_user, &core->clks, clks_node) |
|
*max_rate = min(*max_rate, clk_user->max_rate); |
|
} |
|
|
|
/* |
|
* clk_hw_get_rate_range() - returns the clock rate range for a hw clk |
|
* @hw: the hw clk we want to get the range from |
|
* @min_rate: pointer to the variable that will hold the minimum |
|
* @max_rate: pointer to the variable that will hold the maximum |
|
* |
|
* Fills the @min_rate and @max_rate variables with the minimum and |
|
* maximum that clock can reach. |
|
*/ |
|
void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate, |
|
unsigned long *max_rate) |
|
{ |
|
clk_core_get_boundaries(hw->core, min_rate, max_rate); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_get_rate_range); |
|
|
|
static bool clk_core_check_boundaries(struct clk_core *core, |
|
unsigned long min_rate, |
|
unsigned long max_rate) |
|
{ |
|
struct clk *user; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (min_rate > core->max_rate || max_rate < core->min_rate) |
|
return false; |
|
|
|
hlist_for_each_entry(user, &core->clks, clks_node) |
|
if (min_rate > user->max_rate || max_rate < user->min_rate) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, |
|
unsigned long max_rate) |
|
{ |
|
hw->core->min_rate = min_rate; |
|
hw->core->max_rate = max_rate; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_set_rate_range); |
|
|
|
/* |
|
* __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk |
|
* @hw: mux type clk to determine rate on |
|
* @req: rate request, also used to return preferred parent and frequencies |
|
* |
|
* Helper for finding best parent to provide a given frequency. This can be used |
|
* directly as a determine_rate callback (e.g. for a mux), or from a more |
|
* complex clock that may combine a mux with other operations. |
|
* |
|
* Returns: 0 on success, -EERROR value on error |
|
*/ |
|
int __clk_mux_determine_rate(struct clk_hw *hw, |
|
struct clk_rate_request *req) |
|
{ |
|
return clk_mux_determine_rate_flags(hw, req, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
|
|
|
int __clk_mux_determine_rate_closest(struct clk_hw *hw, |
|
struct clk_rate_request *req) |
|
{ |
|
return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST); |
|
} |
|
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest); |
|
|
|
/*** clk api ***/ |
|
|
|
static void clk_core_rate_unprotect(struct clk_core *core) |
|
{ |
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return; |
|
|
|
if (WARN(core->protect_count == 0, |
|
"%s already unprotected\n", core->name)) |
|
return; |
|
|
|
if (--core->protect_count > 0) |
|
return; |
|
|
|
clk_core_rate_unprotect(core->parent); |
|
} |
|
|
|
static int clk_core_rate_nuke_protect(struct clk_core *core) |
|
{ |
|
int ret; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return -EINVAL; |
|
|
|
if (core->protect_count == 0) |
|
return 0; |
|
|
|
ret = core->protect_count; |
|
core->protect_count = 1; |
|
clk_core_rate_unprotect(core); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_rate_exclusive_put - release exclusivity over clock rate control |
|
* @clk: the clk over which the exclusivity is released |
|
* |
|
* clk_rate_exclusive_put() completes a critical section during which a clock |
|
* consumer cannot tolerate any other consumer making any operation on the |
|
* clock which could result in a rate change or rate glitch. Exclusive clocks |
|
* cannot have their rate changed, either directly or indirectly due to changes |
|
* further up the parent chain of clocks. As a result, clocks up parent chain |
|
* also get under exclusive control of the calling consumer. |
|
* |
|
* If exlusivity is claimed more than once on clock, even by the same consumer, |
|
* the rate effectively gets locked as exclusivity can't be preempted. |
|
* |
|
* Calls to clk_rate_exclusive_put() must be balanced with calls to |
|
* clk_rate_exclusive_get(). Calls to this function may sleep, and do not return |
|
* error status. |
|
*/ |
|
void clk_rate_exclusive_put(struct clk *clk) |
|
{ |
|
if (!clk) |
|
return; |
|
|
|
clk_prepare_lock(); |
|
|
|
/* |
|
* if there is something wrong with this consumer protect count, stop |
|
* here before messing with the provider |
|
*/ |
|
if (WARN_ON(clk->exclusive_count <= 0)) |
|
goto out; |
|
|
|
clk_core_rate_unprotect(clk->core); |
|
clk->exclusive_count--; |
|
out: |
|
clk_prepare_unlock(); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_rate_exclusive_put); |
|
|
|
static void clk_core_rate_protect(struct clk_core *core) |
|
{ |
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return; |
|
|
|
if (core->protect_count == 0) |
|
clk_core_rate_protect(core->parent); |
|
|
|
core->protect_count++; |
|
} |
|
|
|
static void clk_core_rate_restore_protect(struct clk_core *core, int count) |
|
{ |
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return; |
|
|
|
if (count == 0) |
|
return; |
|
|
|
clk_core_rate_protect(core); |
|
core->protect_count = count; |
|
} |
|
|
|
/** |
|
* clk_rate_exclusive_get - get exclusivity over the clk rate control |
|
* @clk: the clk over which the exclusity of rate control is requested |
|
* |
|
* clk_rate_exclusive_get() begins a critical section during which a clock |
|
* consumer cannot tolerate any other consumer making any operation on the |
|
* clock which could result in a rate change or rate glitch. Exclusive clocks |
|
* cannot have their rate changed, either directly or indirectly due to changes |
|
* further up the parent chain of clocks. As a result, clocks up parent chain |
|
* also get under exclusive control of the calling consumer. |
|
* |
|
* If exlusivity is claimed more than once on clock, even by the same consumer, |
|
* the rate effectively gets locked as exclusivity can't be preempted. |
|
* |
|
* Calls to clk_rate_exclusive_get() should be balanced with calls to |
|
* clk_rate_exclusive_put(). Calls to this function may sleep. |
|
* Returns 0 on success, -EERROR otherwise |
|
*/ |
|
int clk_rate_exclusive_get(struct clk *clk) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
clk_core_rate_protect(clk->core); |
|
clk->exclusive_count++; |
|
clk_prepare_unlock(); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_rate_exclusive_get); |
|
|
|
static void clk_core_unprepare(struct clk_core *core) |
|
{ |
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return; |
|
|
|
if (WARN(core->prepare_count == 0, |
|
"%s already unprepared\n", core->name)) |
|
return; |
|
|
|
if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL, |
|
"Unpreparing critical %s\n", core->name)) |
|
return; |
|
|
|
if (core->flags & CLK_SET_RATE_GATE) |
|
clk_core_rate_unprotect(core); |
|
|
|
if (--core->prepare_count > 0) |
|
return; |
|
|
|
WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name); |
|
|
|
trace_clk_unprepare(core); |
|
|
|
if (core->ops->unprepare) |
|
core->ops->unprepare(core->hw); |
|
|
|
trace_clk_unprepare_complete(core); |
|
clk_core_unprepare(core->parent); |
|
clk_pm_runtime_put(core); |
|
} |
|
|
|
static void clk_core_unprepare_lock(struct clk_core *core) |
|
{ |
|
clk_prepare_lock(); |
|
clk_core_unprepare(core); |
|
clk_prepare_unlock(); |
|
} |
|
|
|
/** |
|
* clk_unprepare - undo preparation of a clock source |
|
* @clk: the clk being unprepared |
|
* |
|
* clk_unprepare may sleep, which differentiates it from clk_disable. In a |
|
* simple case, clk_unprepare can be used instead of clk_disable to gate a clk |
|
* if the operation may sleep. One example is a clk which is accessed over |
|
* I2c. In the complex case a clk gate operation may require a fast and a slow |
|
* part. It is this reason that clk_unprepare and clk_disable are not mutually |
|
* exclusive. In fact clk_disable must be called before clk_unprepare. |
|
*/ |
|
void clk_unprepare(struct clk *clk) |
|
{ |
|
if (IS_ERR_OR_NULL(clk)) |
|
return; |
|
|
|
clk_core_unprepare_lock(clk->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_unprepare); |
|
|
|
static int clk_core_prepare(struct clk_core *core) |
|
{ |
|
int ret = 0; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
if (core->prepare_count == 0) { |
|
ret = clk_pm_runtime_get(core); |
|
if (ret) |
|
return ret; |
|
|
|
ret = clk_core_prepare(core->parent); |
|
if (ret) |
|
goto runtime_put; |
|
|
|
trace_clk_prepare(core); |
|
|
|
if (core->ops->prepare) |
|
ret = core->ops->prepare(core->hw); |
|
|
|
trace_clk_prepare_complete(core); |
|
|
|
if (ret) |
|
goto unprepare; |
|
} |
|
|
|
core->prepare_count++; |
|
|
|
/* |
|
* CLK_SET_RATE_GATE is a special case of clock protection |
|
* Instead of a consumer claiming exclusive rate control, it is |
|
* actually the provider which prevents any consumer from making any |
|
* operation which could result in a rate change or rate glitch while |
|
* the clock is prepared. |
|
*/ |
|
if (core->flags & CLK_SET_RATE_GATE) |
|
clk_core_rate_protect(core); |
|
|
|
return 0; |
|
unprepare: |
|
clk_core_unprepare(core->parent); |
|
runtime_put: |
|
clk_pm_runtime_put(core); |
|
return ret; |
|
} |
|
|
|
static int clk_core_prepare_lock(struct clk_core *core) |
|
{ |
|
int ret; |
|
|
|
clk_prepare_lock(); |
|
ret = clk_core_prepare(core); |
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_prepare - prepare a clock source |
|
* @clk: the clk being prepared |
|
* |
|
* clk_prepare may sleep, which differentiates it from clk_enable. In a simple |
|
* case, clk_prepare can be used instead of clk_enable to ungate a clk if the |
|
* operation may sleep. One example is a clk which is accessed over I2c. In |
|
* the complex case a clk ungate operation may require a fast and a slow part. |
|
* It is this reason that clk_prepare and clk_enable are not mutually |
|
* exclusive. In fact clk_prepare must be called before clk_enable. |
|
* Returns 0 on success, -EERROR otherwise. |
|
*/ |
|
int clk_prepare(struct clk *clk) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
return clk_core_prepare_lock(clk->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_prepare); |
|
|
|
static void clk_core_disable(struct clk_core *core) |
|
{ |
|
lockdep_assert_held(&enable_lock); |
|
|
|
if (!core) |
|
return; |
|
|
|
if (WARN(core->enable_count == 0, "%s already disabled\n", core->name)) |
|
return; |
|
|
|
if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL, |
|
"Disabling critical %s\n", core->name)) |
|
return; |
|
|
|
if (--core->enable_count > 0) |
|
return; |
|
|
|
trace_clk_disable_rcuidle(core); |
|
|
|
if (core->ops->disable) |
|
core->ops->disable(core->hw); |
|
|
|
trace_clk_disable_complete_rcuidle(core); |
|
|
|
clk_core_disable(core->parent); |
|
} |
|
|
|
static void clk_core_disable_lock(struct clk_core *core) |
|
{ |
|
unsigned long flags; |
|
|
|
flags = clk_enable_lock(); |
|
clk_core_disable(core); |
|
clk_enable_unlock(flags); |
|
} |
|
|
|
/** |
|
* clk_disable - gate a clock |
|
* @clk: the clk being gated |
|
* |
|
* clk_disable must not sleep, which differentiates it from clk_unprepare. In |
|
* a simple case, clk_disable can be used instead of clk_unprepare to gate a |
|
* clk if the operation is fast and will never sleep. One example is a |
|
* SoC-internal clk which is controlled via simple register writes. In the |
|
* complex case a clk gate operation may require a fast and a slow part. It is |
|
* this reason that clk_unprepare and clk_disable are not mutually exclusive. |
|
* In fact clk_disable must be called before clk_unprepare. |
|
*/ |
|
void clk_disable(struct clk *clk) |
|
{ |
|
if (IS_ERR_OR_NULL(clk)) |
|
return; |
|
|
|
clk_core_disable_lock(clk->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_disable); |
|
|
|
static int clk_core_enable(struct clk_core *core) |
|
{ |
|
int ret = 0; |
|
|
|
lockdep_assert_held(&enable_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
if (WARN(core->prepare_count == 0, |
|
"Enabling unprepared %s\n", core->name)) |
|
return -ESHUTDOWN; |
|
|
|
if (core->enable_count == 0) { |
|
ret = clk_core_enable(core->parent); |
|
|
|
if (ret) |
|
return ret; |
|
|
|
trace_clk_enable_rcuidle(core); |
|
|
|
if (core->ops->enable) |
|
ret = core->ops->enable(core->hw); |
|
|
|
trace_clk_enable_complete_rcuidle(core); |
|
|
|
if (ret) { |
|
clk_core_disable(core->parent); |
|
return ret; |
|
} |
|
} |
|
|
|
core->enable_count++; |
|
return 0; |
|
} |
|
|
|
static int clk_core_enable_lock(struct clk_core *core) |
|
{ |
|
unsigned long flags; |
|
int ret; |
|
|
|
flags = clk_enable_lock(); |
|
ret = clk_core_enable(core); |
|
clk_enable_unlock(flags); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_gate_restore_context - restore context for poweroff |
|
* @hw: the clk_hw pointer of clock whose state is to be restored |
|
* |
|
* The clock gate restore context function enables or disables |
|
* the gate clocks based on the enable_count. This is done in cases |
|
* where the clock context is lost and based on the enable_count |
|
* the clock either needs to be enabled/disabled. This |
|
* helps restore the state of gate clocks. |
|
*/ |
|
void clk_gate_restore_context(struct clk_hw *hw) |
|
{ |
|
struct clk_core *core = hw->core; |
|
|
|
if (core->enable_count) |
|
core->ops->enable(hw); |
|
else |
|
core->ops->disable(hw); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_gate_restore_context); |
|
|
|
static int clk_core_save_context(struct clk_core *core) |
|
{ |
|
struct clk_core *child; |
|
int ret = 0; |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) { |
|
ret = clk_core_save_context(child); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
if (core->ops && core->ops->save_context) |
|
ret = core->ops->save_context(core->hw); |
|
|
|
return ret; |
|
} |
|
|
|
static void clk_core_restore_context(struct clk_core *core) |
|
{ |
|
struct clk_core *child; |
|
|
|
if (core->ops && core->ops->restore_context) |
|
core->ops->restore_context(core->hw); |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
clk_core_restore_context(child); |
|
} |
|
|
|
/** |
|
* clk_save_context - save clock context for poweroff |
|
* |
|
* Saves the context of the clock register for powerstates in which the |
|
* contents of the registers will be lost. Occurs deep within the suspend |
|
* code. Returns 0 on success. |
|
*/ |
|
int clk_save_context(void) |
|
{ |
|
struct clk_core *clk; |
|
int ret; |
|
|
|
hlist_for_each_entry(clk, &clk_root_list, child_node) { |
|
ret = clk_core_save_context(clk); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
hlist_for_each_entry(clk, &clk_orphan_list, child_node) { |
|
ret = clk_core_save_context(clk); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_save_context); |
|
|
|
/** |
|
* clk_restore_context - restore clock context after poweroff |
|
* |
|
* Restore the saved clock context upon resume. |
|
* |
|
*/ |
|
void clk_restore_context(void) |
|
{ |
|
struct clk_core *core; |
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node) |
|
clk_core_restore_context(core); |
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node) |
|
clk_core_restore_context(core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_restore_context); |
|
|
|
/** |
|
* clk_enable - ungate a clock |
|
* @clk: the clk being ungated |
|
* |
|
* clk_enable must not sleep, which differentiates it from clk_prepare. In a |
|
* simple case, clk_enable can be used instead of clk_prepare to ungate a clk |
|
* if the operation will never sleep. One example is a SoC-internal clk which |
|
* is controlled via simple register writes. In the complex case a clk ungate |
|
* operation may require a fast and a slow part. It is this reason that |
|
* clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare |
|
* must be called before clk_enable. Returns 0 on success, -EERROR |
|
* otherwise. |
|
*/ |
|
int clk_enable(struct clk *clk) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
return clk_core_enable_lock(clk->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_enable); |
|
|
|
/** |
|
* clk_is_enabled_when_prepared - indicate if preparing a clock also enables it. |
|
* @clk: clock source |
|
* |
|
* Returns true if clk_prepare() implicitly enables the clock, effectively |
|
* making clk_enable()/clk_disable() no-ops, false otherwise. |
|
* |
|
* This is of interest mainly to power management code where actually |
|
* disabling the clock also requires unpreparing it to have any material |
|
* effect. |
|
* |
|
* Regardless of the value returned here, the caller must always invoke |
|
* clk_enable() or clk_prepare_enable() and counterparts for usage counts |
|
* to be right. |
|
*/ |
|
bool clk_is_enabled_when_prepared(struct clk *clk) |
|
{ |
|
return clk && !(clk->core->ops->enable && clk->core->ops->disable); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared); |
|
|
|
static int clk_core_prepare_enable(struct clk_core *core) |
|
{ |
|
int ret; |
|
|
|
ret = clk_core_prepare_lock(core); |
|
if (ret) |
|
return ret; |
|
|
|
ret = clk_core_enable_lock(core); |
|
if (ret) |
|
clk_core_unprepare_lock(core); |
|
|
|
return ret; |
|
} |
|
|
|
static void clk_core_disable_unprepare(struct clk_core *core) |
|
{ |
|
clk_core_disable_lock(core); |
|
clk_core_unprepare_lock(core); |
|
} |
|
|
|
static void __init clk_unprepare_unused_subtree(struct clk_core *core) |
|
{ |
|
struct clk_core *child; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
clk_unprepare_unused_subtree(child); |
|
|
|
if (core->prepare_count) |
|
return; |
|
|
|
if (core->flags & CLK_IGNORE_UNUSED) |
|
return; |
|
|
|
if (clk_pm_runtime_get(core)) |
|
return; |
|
|
|
if (clk_core_is_prepared(core)) { |
|
trace_clk_unprepare(core); |
|
if (core->ops->unprepare_unused) |
|
core->ops->unprepare_unused(core->hw); |
|
else if (core->ops->unprepare) |
|
core->ops->unprepare(core->hw); |
|
trace_clk_unprepare_complete(core); |
|
} |
|
|
|
clk_pm_runtime_put(core); |
|
} |
|
|
|
static void __init clk_disable_unused_subtree(struct clk_core *core) |
|
{ |
|
struct clk_core *child; |
|
unsigned long flags; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
clk_disable_unused_subtree(child); |
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE) |
|
clk_core_prepare_enable(core->parent); |
|
|
|
if (clk_pm_runtime_get(core)) |
|
goto unprepare_out; |
|
|
|
flags = clk_enable_lock(); |
|
|
|
if (core->enable_count) |
|
goto unlock_out; |
|
|
|
if (core->flags & CLK_IGNORE_UNUSED) |
|
goto unlock_out; |
|
|
|
/* |
|
* some gate clocks have special needs during the disable-unused |
|
* sequence. call .disable_unused if available, otherwise fall |
|
* back to .disable |
|
*/ |
|
if (clk_core_is_enabled(core)) { |
|
trace_clk_disable(core); |
|
if (core->ops->disable_unused) |
|
core->ops->disable_unused(core->hw); |
|
else if (core->ops->disable) |
|
core->ops->disable(core->hw); |
|
trace_clk_disable_complete(core); |
|
} |
|
|
|
unlock_out: |
|
clk_enable_unlock(flags); |
|
clk_pm_runtime_put(core); |
|
unprepare_out: |
|
if (core->flags & CLK_OPS_PARENT_ENABLE) |
|
clk_core_disable_unprepare(core->parent); |
|
} |
|
|
|
static bool clk_ignore_unused __initdata; |
|
static int __init clk_ignore_unused_setup(char *__unused) |
|
{ |
|
clk_ignore_unused = true; |
|
return 1; |
|
} |
|
__setup("clk_ignore_unused", clk_ignore_unused_setup); |
|
|
|
static int __init clk_disable_unused(void) |
|
{ |
|
struct clk_core *core; |
|
|
|
if (clk_ignore_unused) { |
|
pr_warn("clk: Not disabling unused clocks\n"); |
|
return 0; |
|
} |
|
|
|
clk_prepare_lock(); |
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node) |
|
clk_disable_unused_subtree(core); |
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node) |
|
clk_disable_unused_subtree(core); |
|
|
|
hlist_for_each_entry(core, &clk_root_list, child_node) |
|
clk_unprepare_unused_subtree(core); |
|
|
|
hlist_for_each_entry(core, &clk_orphan_list, child_node) |
|
clk_unprepare_unused_subtree(core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return 0; |
|
} |
|
late_initcall_sync(clk_disable_unused); |
|
|
|
static int clk_core_determine_round_nolock(struct clk_core *core, |
|
struct clk_rate_request *req) |
|
{ |
|
long rate; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
/* |
|
* Some clock providers hand-craft their clk_rate_requests and |
|
* might not fill min_rate and max_rate. |
|
* |
|
* If it's the case, clamping the rate is equivalent to setting |
|
* the rate to 0 which is bad. Skip the clamping but complain so |
|
* that it gets fixed, hopefully. |
|
*/ |
|
if (!req->min_rate && !req->max_rate) |
|
pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n", |
|
__func__, core->name); |
|
else |
|
req->rate = clamp(req->rate, req->min_rate, req->max_rate); |
|
|
|
/* |
|
* At this point, core protection will be disabled |
|
* - if the provider is not protected at all |
|
* - if the calling consumer is the only one which has exclusivity |
|
* over the provider |
|
*/ |
|
if (clk_core_rate_is_protected(core)) { |
|
req->rate = core->rate; |
|
} else if (core->ops->determine_rate) { |
|
return core->ops->determine_rate(core->hw, req); |
|
} else if (core->ops->round_rate) { |
|
rate = core->ops->round_rate(core->hw, req->rate, |
|
&req->best_parent_rate); |
|
if (rate < 0) |
|
return rate; |
|
|
|
req->rate = rate; |
|
} else { |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void clk_core_init_rate_req(struct clk_core * const core, |
|
struct clk_rate_request *req, |
|
unsigned long rate) |
|
{ |
|
struct clk_core *parent; |
|
|
|
if (WARN_ON(!req)) |
|
return; |
|
|
|
memset(req, 0, sizeof(*req)); |
|
req->max_rate = ULONG_MAX; |
|
|
|
if (!core) |
|
return; |
|
|
|
req->rate = rate; |
|
clk_core_get_boundaries(core, &req->min_rate, &req->max_rate); |
|
|
|
parent = core->parent; |
|
if (parent) { |
|
req->best_parent_hw = parent->hw; |
|
req->best_parent_rate = parent->rate; |
|
} else { |
|
req->best_parent_hw = NULL; |
|
req->best_parent_rate = 0; |
|
} |
|
} |
|
|
|
/** |
|
* clk_hw_init_rate_request - Initializes a clk_rate_request |
|
* @hw: the clk for which we want to submit a rate request |
|
* @req: the clk_rate_request structure we want to initialise |
|
* @rate: the rate which is to be requested |
|
* |
|
* Initializes a clk_rate_request structure to submit to |
|
* __clk_determine_rate() or similar functions. |
|
*/ |
|
void clk_hw_init_rate_request(const struct clk_hw *hw, |
|
struct clk_rate_request *req, |
|
unsigned long rate) |
|
{ |
|
if (WARN_ON(!hw || !req)) |
|
return; |
|
|
|
clk_core_init_rate_req(hw->core, req, rate); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_init_rate_request); |
|
|
|
/** |
|
* clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent |
|
* @hw: the original clock that got the rate request |
|
* @old_req: the original clk_rate_request structure we want to forward |
|
* @parent: the clk we want to forward @old_req to |
|
* @req: the clk_rate_request structure we want to initialise |
|
* @parent_rate: The rate which is to be requested to @parent |
|
* |
|
* Initializes a clk_rate_request structure to submit to a clock parent |
|
* in __clk_determine_rate() or similar functions. |
|
*/ |
|
void clk_hw_forward_rate_request(const struct clk_hw *hw, |
|
const struct clk_rate_request *old_req, |
|
const struct clk_hw *parent, |
|
struct clk_rate_request *req, |
|
unsigned long parent_rate) |
|
{ |
|
if (WARN_ON(!hw || !old_req || !parent || !req)) |
|
return; |
|
|
|
clk_core_forward_rate_req(hw->core, old_req, |
|
parent->core, req, |
|
parent_rate); |
|
} |
|
|
|
static bool clk_core_can_round(struct clk_core * const core) |
|
{ |
|
return core->ops->determine_rate || core->ops->round_rate; |
|
} |
|
|
|
static int clk_core_round_rate_nolock(struct clk_core *core, |
|
struct clk_rate_request *req) |
|
{ |
|
int ret; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) { |
|
req->rate = 0; |
|
return 0; |
|
} |
|
|
|
if (clk_core_can_round(core)) |
|
return clk_core_determine_round_nolock(core, req); |
|
|
|
if (core->flags & CLK_SET_RATE_PARENT) { |
|
struct clk_rate_request parent_req; |
|
|
|
clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate); |
|
ret = clk_core_round_rate_nolock(core->parent, &parent_req); |
|
if (ret) |
|
return ret; |
|
|
|
req->best_parent_rate = parent_req.rate; |
|
req->rate = parent_req.rate; |
|
|
|
return 0; |
|
} |
|
|
|
req->rate = core->rate; |
|
return 0; |
|
} |
|
|
|
/** |
|
* __clk_determine_rate - get the closest rate actually supported by a clock |
|
* @hw: determine the rate of this clock |
|
* @req: target rate request |
|
* |
|
* Useful for clk_ops such as .set_rate and .determine_rate. |
|
*/ |
|
int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) |
|
{ |
|
if (!hw) { |
|
req->rate = 0; |
|
return 0; |
|
} |
|
|
|
return clk_core_round_rate_nolock(hw->core, req); |
|
} |
|
EXPORT_SYMBOL_GPL(__clk_determine_rate); |
|
|
|
/** |
|
* clk_hw_round_rate() - round the given rate for a hw clk |
|
* @hw: the hw clk for which we are rounding a rate |
|
* @rate: the rate which is to be rounded |
|
* |
|
* Takes in a rate as input and rounds it to a rate that the clk can actually |
|
* use. |
|
* |
|
* Context: prepare_lock must be held. |
|
* For clk providers to call from within clk_ops such as .round_rate, |
|
* .determine_rate. |
|
* |
|
* Return: returns rounded rate of hw clk if clk supports round_rate operation |
|
* else returns the parent rate. |
|
*/ |
|
unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) |
|
{ |
|
int ret; |
|
struct clk_rate_request req; |
|
|
|
clk_core_init_rate_req(hw->core, &req, rate); |
|
|
|
ret = clk_core_round_rate_nolock(hw->core, &req); |
|
if (ret) |
|
return 0; |
|
|
|
return req.rate; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_round_rate); |
|
|
|
/** |
|
* clk_round_rate - round the given rate for a clk |
|
* @clk: the clk for which we are rounding a rate |
|
* @rate: the rate which is to be rounded |
|
* |
|
* Takes in a rate as input and rounds it to a rate that the clk can actually |
|
* use which is then returned. If clk doesn't support round_rate operation |
|
* then the parent rate is returned. |
|
*/ |
|
long clk_round_rate(struct clk *clk, unsigned long rate) |
|
{ |
|
struct clk_rate_request req; |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
clk_core_init_rate_req(clk->core, &req, rate); |
|
|
|
ret = clk_core_round_rate_nolock(clk->core, &req); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
if (ret) |
|
return ret; |
|
|
|
return req.rate; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_round_rate); |
|
|
|
/** |
|
* __clk_notify - call clk notifier chain |
|
* @core: clk that is changing rate |
|
* @msg: clk notifier type (see include/linux/clk.h) |
|
* @old_rate: old clk rate |
|
* @new_rate: new clk rate |
|
* |
|
* Triggers a notifier call chain on the clk rate-change notification |
|
* for 'clk'. Passes a pointer to the struct clk and the previous |
|
* and current rates to the notifier callback. Intended to be called by |
|
* internal clock code only. Returns NOTIFY_DONE from the last driver |
|
* called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if |
|
* a driver returns that. |
|
*/ |
|
static int __clk_notify(struct clk_core *core, unsigned long msg, |
|
unsigned long old_rate, unsigned long new_rate) |
|
{ |
|
struct clk_notifier *cn; |
|
struct clk_notifier_data cnd; |
|
int ret = NOTIFY_DONE; |
|
|
|
cnd.old_rate = old_rate; |
|
cnd.new_rate = new_rate; |
|
|
|
list_for_each_entry(cn, &clk_notifier_list, node) { |
|
if (cn->clk->core == core) { |
|
cnd.clk = cn->clk; |
|
ret = srcu_notifier_call_chain(&cn->notifier_head, msg, |
|
&cnd); |
|
if (ret & NOTIFY_STOP_MASK) |
|
return ret; |
|
} |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* __clk_recalc_accuracies |
|
* @core: first clk in the subtree |
|
* |
|
* Walks the subtree of clks starting with clk and recalculates accuracies as |
|
* it goes. Note that if a clk does not implement the .recalc_accuracy |
|
* callback then it is assumed that the clock will take on the accuracy of its |
|
* parent. |
|
*/ |
|
static void __clk_recalc_accuracies(struct clk_core *core) |
|
{ |
|
unsigned long parent_accuracy = 0; |
|
struct clk_core *child; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (core->parent) |
|
parent_accuracy = core->parent->accuracy; |
|
|
|
if (core->ops->recalc_accuracy) |
|
core->accuracy = core->ops->recalc_accuracy(core->hw, |
|
parent_accuracy); |
|
else |
|
core->accuracy = parent_accuracy; |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
__clk_recalc_accuracies(child); |
|
} |
|
|
|
static long clk_core_get_accuracy_recalc(struct clk_core *core) |
|
{ |
|
if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE)) |
|
__clk_recalc_accuracies(core); |
|
|
|
return clk_core_get_accuracy_no_lock(core); |
|
} |
|
|
|
/** |
|
* clk_get_accuracy - return the accuracy of clk |
|
* @clk: the clk whose accuracy is being returned |
|
* |
|
* Simply returns the cached accuracy of the clk, unless |
|
* CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be |
|
* issued. |
|
* If clk is NULL then returns 0. |
|
*/ |
|
long clk_get_accuracy(struct clk *clk) |
|
{ |
|
long accuracy; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
accuracy = clk_core_get_accuracy_recalc(clk->core); |
|
clk_prepare_unlock(); |
|
|
|
return accuracy; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_get_accuracy); |
|
|
|
static unsigned long clk_recalc(struct clk_core *core, |
|
unsigned long parent_rate) |
|
{ |
|
unsigned long rate = parent_rate; |
|
|
|
if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) { |
|
rate = core->ops->recalc_rate(core->hw, parent_rate); |
|
clk_pm_runtime_put(core); |
|
} |
|
return rate; |
|
} |
|
|
|
/** |
|
* __clk_recalc_rates |
|
* @core: first clk in the subtree |
|
* @update_req: Whether req_rate should be updated with the new rate |
|
* @msg: notification type (see include/linux/clk.h) |
|
* |
|
* Walks the subtree of clks starting with clk and recalculates rates as it |
|
* goes. Note that if a clk does not implement the .recalc_rate callback then |
|
* it is assumed that the clock will take on the rate of its parent. |
|
* |
|
* clk_recalc_rates also propagates the POST_RATE_CHANGE notification, |
|
* if necessary. |
|
*/ |
|
static void __clk_recalc_rates(struct clk_core *core, bool update_req, |
|
unsigned long msg) |
|
{ |
|
unsigned long old_rate; |
|
unsigned long parent_rate = 0; |
|
struct clk_core *child; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
old_rate = core->rate; |
|
|
|
if (core->parent) |
|
parent_rate = core->parent->rate; |
|
|
|
core->rate = clk_recalc(core, parent_rate); |
|
if (update_req) |
|
core->req_rate = core->rate; |
|
|
|
/* |
|
* ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE |
|
* & ABORT_RATE_CHANGE notifiers |
|
*/ |
|
if (core->notifier_count && msg) |
|
__clk_notify(core, msg, old_rate, core->rate); |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
__clk_recalc_rates(child, update_req, msg); |
|
} |
|
|
|
static unsigned long clk_core_get_rate_recalc(struct clk_core *core) |
|
{ |
|
if (core && (core->flags & CLK_GET_RATE_NOCACHE)) |
|
__clk_recalc_rates(core, false, 0); |
|
|
|
return clk_core_get_rate_nolock(core); |
|
} |
|
|
|
/** |
|
* clk_get_rate - return the rate of clk |
|
* @clk: the clk whose rate is being returned |
|
* |
|
* Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag |
|
* is set, which means a recalc_rate will be issued. Can be called regardless of |
|
* the clock enabledness. If clk is NULL, or if an error occurred, then returns |
|
* 0. |
|
*/ |
|
unsigned long clk_get_rate(struct clk *clk) |
|
{ |
|
unsigned long rate; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
rate = clk_core_get_rate_recalc(clk->core); |
|
clk_prepare_unlock(); |
|
|
|
return rate; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_get_rate); |
|
|
|
static int clk_fetch_parent_index(struct clk_core *core, |
|
struct clk_core *parent) |
|
{ |
|
int i; |
|
|
|
if (!parent) |
|
return -EINVAL; |
|
|
|
for (i = 0; i < core->num_parents; i++) { |
|
/* Found it first try! */ |
|
if (core->parents[i].core == parent) |
|
return i; |
|
|
|
/* Something else is here, so keep looking */ |
|
if (core->parents[i].core) |
|
continue; |
|
|
|
/* Maybe core hasn't been cached but the hw is all we know? */ |
|
if (core->parents[i].hw) { |
|
if (core->parents[i].hw == parent->hw) |
|
break; |
|
|
|
/* Didn't match, but we're expecting a clk_hw */ |
|
continue; |
|
} |
|
|
|
/* Maybe it hasn't been cached (clk_set_parent() path) */ |
|
if (parent == clk_core_get(core, i)) |
|
break; |
|
|
|
/* Fallback to comparing globally unique names */ |
|
if (core->parents[i].name && |
|
!strcmp(parent->name, core->parents[i].name)) |
|
break; |
|
} |
|
|
|
if (i == core->num_parents) |
|
return -EINVAL; |
|
|
|
core->parents[i].core = parent; |
|
return i; |
|
} |
|
|
|
/** |
|
* clk_hw_get_parent_index - return the index of the parent clock |
|
* @hw: clk_hw associated with the clk being consumed |
|
* |
|
* Fetches and returns the index of parent clock. Returns -EINVAL if the given |
|
* clock does not have a current parent. |
|
*/ |
|
int clk_hw_get_parent_index(struct clk_hw *hw) |
|
{ |
|
struct clk_hw *parent = clk_hw_get_parent(hw); |
|
|
|
if (WARN_ON(parent == NULL)) |
|
return -EINVAL; |
|
|
|
return clk_fetch_parent_index(hw->core, parent->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_get_parent_index); |
|
|
|
/* |
|
* Update the orphan status of @core and all its children. |
|
*/ |
|
static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) |
|
{ |
|
struct clk_core *child; |
|
|
|
core->orphan = is_orphan; |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) |
|
clk_core_update_orphan_status(child, is_orphan); |
|
} |
|
|
|
static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) |
|
{ |
|
bool was_orphan = core->orphan; |
|
|
|
hlist_del(&core->child_node); |
|
|
|
if (new_parent) { |
|
bool becomes_orphan = new_parent->orphan; |
|
|
|
/* avoid duplicate POST_RATE_CHANGE notifications */ |
|
if (new_parent->new_child == core) |
|
new_parent->new_child = NULL; |
|
|
|
hlist_add_head(&core->child_node, &new_parent->children); |
|
|
|
if (was_orphan != becomes_orphan) |
|
clk_core_update_orphan_status(core, becomes_orphan); |
|
} else { |
|
hlist_add_head(&core->child_node, &clk_orphan_list); |
|
if (!was_orphan) |
|
clk_core_update_orphan_status(core, true); |
|
} |
|
|
|
core->parent = new_parent; |
|
} |
|
|
|
static struct clk_core *__clk_set_parent_before(struct clk_core *core, |
|
struct clk_core *parent) |
|
{ |
|
unsigned long flags; |
|
struct clk_core *old_parent = core->parent; |
|
|
|
/* |
|
* 1. enable parents for CLK_OPS_PARENT_ENABLE clock |
|
* |
|
* 2. Migrate prepare state between parents and prevent race with |
|
* clk_enable(). |
|
* |
|
* If the clock is not prepared, then a race with |
|
* clk_enable/disable() is impossible since we already have the |
|
* prepare lock (future calls to clk_enable() need to be preceded by |
|
* a clk_prepare()). |
|
* |
|
* If the clock is prepared, migrate the prepared state to the new |
|
* parent and also protect against a race with clk_enable() by |
|
* forcing the clock and the new parent on. This ensures that all |
|
* future calls to clk_enable() are practically NOPs with respect to |
|
* hardware and software states. |
|
* |
|
* See also: Comment for clk_set_parent() below. |
|
*/ |
|
|
|
/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */ |
|
if (core->flags & CLK_OPS_PARENT_ENABLE) { |
|
clk_core_prepare_enable(old_parent); |
|
clk_core_prepare_enable(parent); |
|
} |
|
|
|
/* migrate prepare count if > 0 */ |
|
if (core->prepare_count) { |
|
clk_core_prepare_enable(parent); |
|
clk_core_enable_lock(core); |
|
} |
|
|
|
/* update the clk tree topology */ |
|
flags = clk_enable_lock(); |
|
clk_reparent(core, parent); |
|
clk_enable_unlock(flags); |
|
|
|
return old_parent; |
|
} |
|
|
|
static void __clk_set_parent_after(struct clk_core *core, |
|
struct clk_core *parent, |
|
struct clk_core *old_parent) |
|
{ |
|
/* |
|
* Finish the migration of prepare state and undo the changes done |
|
* for preventing a race with clk_enable(). |
|
*/ |
|
if (core->prepare_count) { |
|
clk_core_disable_lock(core); |
|
clk_core_disable_unprepare(old_parent); |
|
} |
|
|
|
/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */ |
|
if (core->flags & CLK_OPS_PARENT_ENABLE) { |
|
clk_core_disable_unprepare(parent); |
|
clk_core_disable_unprepare(old_parent); |
|
} |
|
} |
|
|
|
static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, |
|
u8 p_index) |
|
{ |
|
unsigned long flags; |
|
int ret = 0; |
|
struct clk_core *old_parent; |
|
|
|
old_parent = __clk_set_parent_before(core, parent); |
|
|
|
trace_clk_set_parent(core, parent); |
|
|
|
/* change clock input source */ |
|
if (parent && core->ops->set_parent) |
|
ret = core->ops->set_parent(core->hw, p_index); |
|
|
|
trace_clk_set_parent_complete(core, parent); |
|
|
|
if (ret) { |
|
flags = clk_enable_lock(); |
|
clk_reparent(core, old_parent); |
|
clk_enable_unlock(flags); |
|
|
|
__clk_set_parent_after(core, old_parent, parent); |
|
|
|
return ret; |
|
} |
|
|
|
__clk_set_parent_after(core, parent, old_parent); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* __clk_speculate_rates |
|
* @core: first clk in the subtree |
|
* @parent_rate: the "future" rate of clk's parent |
|
* |
|
* Walks the subtree of clks starting with clk, speculating rates as it |
|
* goes and firing off PRE_RATE_CHANGE notifications as necessary. |
|
* |
|
* Unlike clk_recalc_rates, clk_speculate_rates exists only for sending |
|
* pre-rate change notifications and returns early if no clks in the |
|
* subtree have subscribed to the notifications. Note that if a clk does not |
|
* implement the .recalc_rate callback then it is assumed that the clock will |
|
* take on the rate of its parent. |
|
*/ |
|
static int __clk_speculate_rates(struct clk_core *core, |
|
unsigned long parent_rate) |
|
{ |
|
struct clk_core *child; |
|
unsigned long new_rate; |
|
int ret = NOTIFY_DONE; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
new_rate = clk_recalc(core, parent_rate); |
|
|
|
/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
|
if (core->notifier_count) |
|
ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate); |
|
|
|
if (ret & NOTIFY_STOP_MASK) { |
|
pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", |
|
__func__, core->name, ret); |
|
goto out; |
|
} |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) { |
|
ret = __clk_speculate_rates(child, new_rate); |
|
if (ret & NOTIFY_STOP_MASK) |
|
break; |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, |
|
struct clk_core *new_parent, u8 p_index) |
|
{ |
|
struct clk_core *child; |
|
|
|
core->new_rate = new_rate; |
|
core->new_parent = new_parent; |
|
core->new_parent_index = p_index; |
|
/* include clk in new parent's PRE_RATE_CHANGE notifications */ |
|
core->new_child = NULL; |
|
if (new_parent && new_parent != core->parent) |
|
new_parent->new_child = core; |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) { |
|
child->new_rate = clk_recalc(child, new_rate); |
|
clk_calc_subtree(child, child->new_rate, NULL, 0); |
|
} |
|
} |
|
|
|
/* |
|
* calculate the new rates returning the topmost clock that has to be |
|
* changed. |
|
*/ |
|
static struct clk_core *clk_calc_new_rates(struct clk_core *core, |
|
unsigned long rate) |
|
{ |
|
struct clk_core *top = core; |
|
struct clk_core *old_parent, *parent; |
|
unsigned long best_parent_rate = 0; |
|
unsigned long new_rate; |
|
unsigned long min_rate; |
|
unsigned long max_rate; |
|
int p_index = 0; |
|
long ret; |
|
|
|
/* sanity */ |
|
if (IS_ERR_OR_NULL(core)) |
|
return NULL; |
|
|
|
/* save parent rate, if it exists */ |
|
parent = old_parent = core->parent; |
|
if (parent) |
|
best_parent_rate = parent->rate; |
|
|
|
clk_core_get_boundaries(core, &min_rate, &max_rate); |
|
|
|
/* find the closest rate and parent clk/rate */ |
|
if (clk_core_can_round(core)) { |
|
struct clk_rate_request req; |
|
|
|
clk_core_init_rate_req(core, &req, rate); |
|
|
|
ret = clk_core_determine_round_nolock(core, &req); |
|
if (ret < 0) |
|
return NULL; |
|
|
|
best_parent_rate = req.best_parent_rate; |
|
new_rate = req.rate; |
|
parent = req.best_parent_hw ? req.best_parent_hw->core : NULL; |
|
|
|
if (new_rate < min_rate || new_rate > max_rate) |
|
return NULL; |
|
} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) { |
|
/* pass-through clock without adjustable parent */ |
|
core->new_rate = core->rate; |
|
return NULL; |
|
} else { |
|
/* pass-through clock with adjustable parent */ |
|
top = clk_calc_new_rates(parent, rate); |
|
new_rate = parent->new_rate; |
|
goto out; |
|
} |
|
|
|
/* some clocks must be gated to change parent */ |
|
if (parent != old_parent && |
|
(core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) { |
|
pr_debug("%s: %s not gated but wants to reparent\n", |
|
__func__, core->name); |
|
return NULL; |
|
} |
|
|
|
/* try finding the new parent index */ |
|
if (parent && core->num_parents > 1) { |
|
p_index = clk_fetch_parent_index(core, parent); |
|
if (p_index < 0) { |
|
pr_debug("%s: clk %s can not be parent of clk %s\n", |
|
__func__, parent->name, core->name); |
|
return NULL; |
|
} |
|
} |
|
|
|
if ((core->flags & CLK_SET_RATE_PARENT) && parent && |
|
best_parent_rate != parent->rate) |
|
top = clk_calc_new_rates(parent, best_parent_rate); |
|
|
|
out: |
|
clk_calc_subtree(core, new_rate, parent, p_index); |
|
|
|
return top; |
|
} |
|
|
|
/* |
|
* Notify about rate changes in a subtree. Always walk down the whole tree |
|
* so that in case of an error we can walk down the whole tree again and |
|
* abort the change. |
|
*/ |
|
static struct clk_core *clk_propagate_rate_change(struct clk_core *core, |
|
unsigned long event) |
|
{ |
|
struct clk_core *child, *tmp_clk, *fail_clk = NULL; |
|
int ret = NOTIFY_DONE; |
|
|
|
if (core->rate == core->new_rate) |
|
return NULL; |
|
|
|
if (core->notifier_count) { |
|
ret = __clk_notify(core, event, core->rate, core->new_rate); |
|
if (ret & NOTIFY_STOP_MASK) |
|
fail_clk = core; |
|
} |
|
|
|
hlist_for_each_entry(child, &core->children, child_node) { |
|
/* Skip children who will be reparented to another clock */ |
|
if (child->new_parent && child->new_parent != core) |
|
continue; |
|
tmp_clk = clk_propagate_rate_change(child, event); |
|
if (tmp_clk) |
|
fail_clk = tmp_clk; |
|
} |
|
|
|
/* handle the new child who might not be in core->children yet */ |
|
if (core->new_child) { |
|
tmp_clk = clk_propagate_rate_change(core->new_child, event); |
|
if (tmp_clk) |
|
fail_clk = tmp_clk; |
|
} |
|
|
|
return fail_clk; |
|
} |
|
|
|
/* |
|
* walk down a subtree and set the new rates notifying the rate |
|
* change on the way |
|
*/ |
|
static void clk_change_rate(struct clk_core *core) |
|
{ |
|
struct clk_core *child; |
|
struct hlist_node *tmp; |
|
unsigned long old_rate; |
|
unsigned long best_parent_rate = 0; |
|
bool skip_set_rate = false; |
|
struct clk_core *old_parent; |
|
struct clk_core *parent = NULL; |
|
|
|
old_rate = core->rate; |
|
|
|
if (core->new_parent) { |
|
parent = core->new_parent; |
|
best_parent_rate = core->new_parent->rate; |
|
} else if (core->parent) { |
|
parent = core->parent; |
|
best_parent_rate = core->parent->rate; |
|
} |
|
|
|
if (clk_pm_runtime_get(core)) |
|
return; |
|
|
|
if (core->flags & CLK_SET_RATE_UNGATE) { |
|
clk_core_prepare(core); |
|
clk_core_enable_lock(core); |
|
} |
|
|
|
if (core->new_parent && core->new_parent != core->parent) { |
|
old_parent = __clk_set_parent_before(core, core->new_parent); |
|
trace_clk_set_parent(core, core->new_parent); |
|
|
|
if (core->ops->set_rate_and_parent) { |
|
skip_set_rate = true; |
|
core->ops->set_rate_and_parent(core->hw, core->new_rate, |
|
best_parent_rate, |
|
core->new_parent_index); |
|
} else if (core->ops->set_parent) { |
|
core->ops->set_parent(core->hw, core->new_parent_index); |
|
} |
|
|
|
trace_clk_set_parent_complete(core, core->new_parent); |
|
__clk_set_parent_after(core, core->new_parent, old_parent); |
|
} |
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE) |
|
clk_core_prepare_enable(parent); |
|
|
|
trace_clk_set_rate(core, core->new_rate); |
|
|
|
if (!skip_set_rate && core->ops->set_rate) |
|
core->ops->set_rate(core->hw, core->new_rate, best_parent_rate); |
|
|
|
trace_clk_set_rate_complete(core, core->new_rate); |
|
|
|
core->rate = clk_recalc(core, best_parent_rate); |
|
|
|
if (core->flags & CLK_SET_RATE_UNGATE) { |
|
clk_core_disable_lock(core); |
|
clk_core_unprepare(core); |
|
} |
|
|
|
if (core->flags & CLK_OPS_PARENT_ENABLE) |
|
clk_core_disable_unprepare(parent); |
|
|
|
if (core->notifier_count && old_rate != core->rate) |
|
__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate); |
|
|
|
if (core->flags & CLK_RECALC_NEW_RATES) |
|
(void)clk_calc_new_rates(core, core->new_rate); |
|
|
|
/* |
|
* Use safe iteration, as change_rate can actually swap parents |
|
* for certain clock types. |
|
*/ |
|
hlist_for_each_entry_safe(child, tmp, &core->children, child_node) { |
|
/* Skip children who will be reparented to another clock */ |
|
if (child->new_parent && child->new_parent != core) |
|
continue; |
|
clk_change_rate(child); |
|
} |
|
|
|
/* handle the new child who might not be in core->children yet */ |
|
if (core->new_child) |
|
clk_change_rate(core->new_child); |
|
|
|
clk_pm_runtime_put(core); |
|
} |
|
|
|
static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, |
|
unsigned long req_rate) |
|
{ |
|
int ret, cnt; |
|
struct clk_rate_request req; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
/* simulate what the rate would be if it could be freely set */ |
|
cnt = clk_core_rate_nuke_protect(core); |
|
if (cnt < 0) |
|
return cnt; |
|
|
|
clk_core_init_rate_req(core, &req, req_rate); |
|
|
|
ret = clk_core_round_rate_nolock(core, &req); |
|
|
|
/* restore the protection */ |
|
clk_core_rate_restore_protect(core, cnt); |
|
|
|
return ret ? 0 : req.rate; |
|
} |
|
|
|
static int clk_core_set_rate_nolock(struct clk_core *core, |
|
unsigned long req_rate) |
|
{ |
|
struct clk_core *top, *fail_clk; |
|
unsigned long rate; |
|
int ret; |
|
|
|
if (!core) |
|
return 0; |
|
|
|
rate = clk_core_req_round_rate_nolock(core, req_rate); |
|
|
|
/* bail early if nothing to do */ |
|
if (rate == clk_core_get_rate_nolock(core)) |
|
return 0; |
|
|
|
/* fail on a direct rate set of a protected provider */ |
|
if (clk_core_rate_is_protected(core)) |
|
return -EBUSY; |
|
|
|
/* calculate new rates and get the topmost changed clock */ |
|
top = clk_calc_new_rates(core, req_rate); |
|
if (!top) |
|
return -EINVAL; |
|
|
|
ret = clk_pm_runtime_get(core); |
|
if (ret) |
|
return ret; |
|
|
|
/* notify that we are about to change rates */ |
|
fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); |
|
if (fail_clk) { |
|
pr_debug("%s: failed to set %s rate\n", __func__, |
|
fail_clk->name); |
|
clk_propagate_rate_change(top, ABORT_RATE_CHANGE); |
|
ret = -EBUSY; |
|
goto err; |
|
} |
|
|
|
/* change the rates */ |
|
clk_change_rate(top); |
|
|
|
core->req_rate = req_rate; |
|
err: |
|
clk_pm_runtime_put(core); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_set_rate - specify a new rate for clk |
|
* @clk: the clk whose rate is being changed |
|
* @rate: the new rate for clk |
|
* |
|
* In the simplest case clk_set_rate will only adjust the rate of clk. |
|
* |
|
* Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
|
* propagate up to clk's parent; whether or not this happens depends on the |
|
* outcome of clk's .round_rate implementation. If *parent_rate is unchanged |
|
* after calling .round_rate then upstream parent propagation is ignored. If |
|
* *parent_rate comes back with a new rate for clk's parent then we propagate |
|
* up to clk's parent and set its rate. Upward propagation will continue |
|
* until either a clk does not support the CLK_SET_RATE_PARENT flag or |
|
* .round_rate stops requesting changes to clk's parent_rate. |
|
* |
|
* Rate changes are accomplished via tree traversal that also recalculates the |
|
* rates for the clocks and fires off POST_RATE_CHANGE notifiers. |
|
* |
|
* Returns 0 on success, -EERROR otherwise. |
|
*/ |
|
int clk_set_rate(struct clk *clk, unsigned long rate) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
/* prevent racing with updates to the clock topology */ |
|
clk_prepare_lock(); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_rate); |
|
|
|
/** |
|
* clk_set_rate_exclusive - specify a new rate and get exclusive control |
|
* @clk: the clk whose rate is being changed |
|
* @rate: the new rate for clk |
|
* |
|
* This is a combination of clk_set_rate() and clk_rate_exclusive_get() |
|
* within a critical section |
|
* |
|
* This can be used initially to ensure that at least 1 consumer is |
|
* satisfied when several consumers are competing for exclusivity over the |
|
* same clock provider. |
|
* |
|
* The exclusivity is not applied if setting the rate failed. |
|
* |
|
* Calls to clk_rate_exclusive_get() should be balanced with calls to |
|
* clk_rate_exclusive_put(). |
|
* |
|
* Returns 0 on success, -EERROR otherwise. |
|
*/ |
|
int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
/* prevent racing with updates to the clock topology */ |
|
clk_prepare_lock(); |
|
|
|
/* |
|
* The temporary protection removal is not here, on purpose |
|
* This function is meant to be used instead of clk_rate_protect, |
|
* so before the consumer code path protect the clock provider |
|
*/ |
|
|
|
ret = clk_core_set_rate_nolock(clk->core, rate); |
|
if (!ret) { |
|
clk_core_rate_protect(clk->core); |
|
clk->exclusive_count++; |
|
} |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_rate_exclusive); |
|
|
|
static int clk_set_rate_range_nolock(struct clk *clk, |
|
unsigned long min, |
|
unsigned long max) |
|
{ |
|
int ret = 0; |
|
unsigned long old_min, old_max, rate; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
trace_clk_set_rate_range(clk->core, min, max); |
|
|
|
if (min > max) { |
|
pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n", |
|
__func__, clk->core->name, clk->dev_id, clk->con_id, |
|
min, max); |
|
return -EINVAL; |
|
} |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
/* Save the current values in case we need to rollback the change */ |
|
old_min = clk->min_rate; |
|
old_max = clk->max_rate; |
|
clk->min_rate = min; |
|
clk->max_rate = max; |
|
|
|
if (!clk_core_check_boundaries(clk->core, min, max)) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
rate = clk->core->req_rate; |
|
if (clk->core->flags & CLK_GET_RATE_NOCACHE) |
|
rate = clk_core_get_rate_recalc(clk->core); |
|
|
|
/* |
|
* Since the boundaries have been changed, let's give the |
|
* opportunity to the provider to adjust the clock rate based on |
|
* the new boundaries. |
|
* |
|
* We also need to handle the case where the clock is currently |
|
* outside of the boundaries. Clamping the last requested rate |
|
* to the current minimum and maximum will also handle this. |
|
* |
|
* FIXME: |
|
* There is a catch. It may fail for the usual reason (clock |
|
* broken, clock protected, etc) but also because: |
|
* - round_rate() was not favorable and fell on the wrong |
|
* side of the boundary |
|
* - the determine_rate() callback does not really check for |
|
* this corner case when determining the rate |
|
*/ |
|
rate = clamp(rate, min, max); |
|
ret = clk_core_set_rate_nolock(clk->core, rate); |
|
if (ret) { |
|
/* rollback the changes */ |
|
clk->min_rate = old_min; |
|
clk->max_rate = old_max; |
|
} |
|
|
|
out: |
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_set_rate_range - set a rate range for a clock source |
|
* @clk: clock source |
|
* @min: desired minimum clock rate in Hz, inclusive |
|
* @max: desired maximum clock rate in Hz, inclusive |
|
* |
|
* Return: 0 for success or negative errno on failure. |
|
*/ |
|
int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
|
|
ret = clk_set_rate_range_nolock(clk, min, max); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_rate_range); |
|
|
|
/** |
|
* clk_set_min_rate - set a minimum clock rate for a clock source |
|
* @clk: clock source |
|
* @rate: desired minimum clock rate in Hz, inclusive |
|
* |
|
* Returns success (0) or negative errno. |
|
*/ |
|
int clk_set_min_rate(struct clk *clk, unsigned long rate) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
trace_clk_set_min_rate(clk->core, rate); |
|
|
|
return clk_set_rate_range(clk, rate, clk->max_rate); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_min_rate); |
|
|
|
/** |
|
* clk_set_max_rate - set a maximum clock rate for a clock source |
|
* @clk: clock source |
|
* @rate: desired maximum clock rate in Hz, inclusive |
|
* |
|
* Returns success (0) or negative errno. |
|
*/ |
|
int clk_set_max_rate(struct clk *clk, unsigned long rate) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
trace_clk_set_max_rate(clk->core, rate); |
|
|
|
return clk_set_rate_range(clk, clk->min_rate, rate); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_max_rate); |
|
|
|
/** |
|
* clk_get_parent - return the parent of a clk |
|
* @clk: the clk whose parent gets returned |
|
* |
|
* Simply returns clk->parent. Returns NULL if clk is NULL. |
|
*/ |
|
struct clk *clk_get_parent(struct clk *clk) |
|
{ |
|
struct clk *parent; |
|
|
|
if (!clk) |
|
return NULL; |
|
|
|
clk_prepare_lock(); |
|
/* TODO: Create a per-user clk and change callers to call clk_put */ |
|
parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk; |
|
clk_prepare_unlock(); |
|
|
|
return parent; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_get_parent); |
|
|
|
static struct clk_core *__clk_init_parent(struct clk_core *core) |
|
{ |
|
u8 index = 0; |
|
|
|
if (core->num_parents > 1 && core->ops->get_parent) |
|
index = core->ops->get_parent(core->hw); |
|
|
|
return clk_core_get_parent_by_index(core, index); |
|
} |
|
|
|
static void clk_core_reparent(struct clk_core *core, |
|
struct clk_core *new_parent) |
|
{ |
|
clk_reparent(core, new_parent); |
|
__clk_recalc_accuracies(core); |
|
__clk_recalc_rates(core, true, POST_RATE_CHANGE); |
|
} |
|
|
|
void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) |
|
{ |
|
if (!hw) |
|
return; |
|
|
|
clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core); |
|
} |
|
|
|
/** |
|
* clk_has_parent - check if a clock is a possible parent for another |
|
* @clk: clock source |
|
* @parent: parent clock source |
|
* |
|
* This function can be used in drivers that need to check that a clock can be |
|
* the parent of another without actually changing the parent. |
|
* |
|
* Returns true if @parent is a possible parent for @clk, false otherwise. |
|
*/ |
|
bool clk_has_parent(const struct clk *clk, const struct clk *parent) |
|
{ |
|
/* NULL clocks should be nops, so return success if either is NULL. */ |
|
if (!clk || !parent) |
|
return true; |
|
|
|
return clk_core_has_parent(clk->core, parent->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_has_parent); |
|
|
|
static int clk_core_set_parent_nolock(struct clk_core *core, |
|
struct clk_core *parent) |
|
{ |
|
int ret = 0; |
|
int p_index = 0; |
|
unsigned long p_rate = 0; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
if (core->parent == parent) |
|
return 0; |
|
|
|
/* verify ops for multi-parent clks */ |
|
if (core->num_parents > 1 && !core->ops->set_parent) |
|
return -EPERM; |
|
|
|
/* check that we are allowed to re-parent if the clock is in use */ |
|
if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) |
|
return -EBUSY; |
|
|
|
if (clk_core_rate_is_protected(core)) |
|
return -EBUSY; |
|
|
|
/* try finding the new parent index */ |
|
if (parent) { |
|
p_index = clk_fetch_parent_index(core, parent); |
|
if (p_index < 0) { |
|
pr_debug("%s: clk %s can not be parent of clk %s\n", |
|
__func__, parent->name, core->name); |
|
return p_index; |
|
} |
|
p_rate = parent->rate; |
|
} |
|
|
|
ret = clk_pm_runtime_get(core); |
|
if (ret) |
|
return ret; |
|
|
|
/* propagate PRE_RATE_CHANGE notifications */ |
|
ret = __clk_speculate_rates(core, p_rate); |
|
|
|
/* abort if a driver objects */ |
|
if (ret & NOTIFY_STOP_MASK) |
|
goto runtime_put; |
|
|
|
/* do the re-parent */ |
|
ret = __clk_set_parent(core, parent, p_index); |
|
|
|
/* propagate rate an accuracy recalculation accordingly */ |
|
if (ret) { |
|
__clk_recalc_rates(core, true, ABORT_RATE_CHANGE); |
|
} else { |
|
__clk_recalc_rates(core, true, POST_RATE_CHANGE); |
|
__clk_recalc_accuracies(core); |
|
} |
|
|
|
runtime_put: |
|
clk_pm_runtime_put(core); |
|
|
|
return ret; |
|
} |
|
|
|
int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent) |
|
{ |
|
return clk_core_set_parent_nolock(hw->core, parent->core); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_set_parent); |
|
|
|
/** |
|
* clk_set_parent - switch the parent of a mux clk |
|
* @clk: the mux clk whose input we are switching |
|
* @parent: the new input to clk |
|
* |
|
* Re-parent clk to use parent as its new input source. If clk is in |
|
* prepared state, the clk will get enabled for the duration of this call. If |
|
* that's not acceptable for a specific clk (Eg: the consumer can't handle |
|
* that, the reparenting is glitchy in hardware, etc), use the |
|
* CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. |
|
* |
|
* After successfully changing clk's parent clk_set_parent will update the |
|
* clk topology, sysfs topology and propagate rate recalculation via |
|
* __clk_recalc_rates. |
|
* |
|
* Returns 0 on success, -EERROR otherwise. |
|
*/ |
|
int clk_set_parent(struct clk *clk, struct clk *parent) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
ret = clk_core_set_parent_nolock(clk->core, |
|
parent ? parent->core : NULL); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_parent); |
|
|
|
static int clk_core_set_phase_nolock(struct clk_core *core, int degrees) |
|
{ |
|
int ret = -EINVAL; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (!core) |
|
return 0; |
|
|
|
if (clk_core_rate_is_protected(core)) |
|
return -EBUSY; |
|
|
|
trace_clk_set_phase(core, degrees); |
|
|
|
if (core->ops->set_phase) { |
|
ret = core->ops->set_phase(core->hw, degrees); |
|
if (!ret) |
|
core->phase = degrees; |
|
} |
|
|
|
trace_clk_set_phase_complete(core, degrees); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_set_phase - adjust the phase shift of a clock signal |
|
* @clk: clock signal source |
|
* @degrees: number of degrees the signal is shifted |
|
* |
|
* Shifts the phase of a clock signal by the specified |
|
* degrees. Returns 0 on success, -EERROR otherwise. |
|
* |
|
* This function makes no distinction about the input or reference |
|
* signal that we adjust the clock signal phase against. For example |
|
* phase locked-loop clock signal generators we may shift phase with |
|
* respect to feedback clock signal input, but for other cases the |
|
* clock phase may be shifted with respect to some other, unspecified |
|
* signal. |
|
* |
|
* Additionally the concept of phase shift does not propagate through |
|
* the clock tree hierarchy, which sets it apart from clock rates and |
|
* clock accuracy. A parent clock phase attribute does not have an |
|
* impact on the phase attribute of a child clock. |
|
*/ |
|
int clk_set_phase(struct clk *clk, int degrees) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
/* sanity check degrees */ |
|
degrees %= 360; |
|
if (degrees < 0) |
|
degrees += 360; |
|
|
|
clk_prepare_lock(); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
ret = clk_core_set_phase_nolock(clk->core, degrees); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_phase); |
|
|
|
static int clk_core_get_phase(struct clk_core *core) |
|
{ |
|
int ret; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
if (!core->ops->get_phase) |
|
return 0; |
|
|
|
/* Always try to update cached phase if possible */ |
|
ret = core->ops->get_phase(core->hw); |
|
if (ret >= 0) |
|
core->phase = ret; |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_get_phase - return the phase shift of a clock signal |
|
* @clk: clock signal source |
|
* |
|
* Returns the phase shift of a clock node in degrees, otherwise returns |
|
* -EERROR. |
|
*/ |
|
int clk_get_phase(struct clk *clk) |
|
{ |
|
int ret; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
clk_prepare_lock(); |
|
ret = clk_core_get_phase(clk->core); |
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_get_phase); |
|
|
|
static void clk_core_reset_duty_cycle_nolock(struct clk_core *core) |
|
{ |
|
/* Assume a default value of 50% */ |
|
core->duty.num = 1; |
|
core->duty.den = 2; |
|
} |
|
|
|
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core); |
|
|
|
static int clk_core_update_duty_cycle_nolock(struct clk_core *core) |
|
{ |
|
struct clk_duty *duty = &core->duty; |
|
int ret = 0; |
|
|
|
if (!core->ops->get_duty_cycle) |
|
return clk_core_update_duty_cycle_parent_nolock(core); |
|
|
|
ret = core->ops->get_duty_cycle(core->hw, duty); |
|
if (ret) |
|
goto reset; |
|
|
|
/* Don't trust the clock provider too much */ |
|
if (duty->den == 0 || duty->num > duty->den) { |
|
ret = -EINVAL; |
|
goto reset; |
|
} |
|
|
|
return 0; |
|
|
|
reset: |
|
clk_core_reset_duty_cycle_nolock(core); |
|
return ret; |
|
} |
|
|
|
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core) |
|
{ |
|
int ret = 0; |
|
|
|
if (core->parent && |
|
core->flags & CLK_DUTY_CYCLE_PARENT) { |
|
ret = clk_core_update_duty_cycle_nolock(core->parent); |
|
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty)); |
|
} else { |
|
clk_core_reset_duty_cycle_nolock(core); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, |
|
struct clk_duty *duty); |
|
|
|
static int clk_core_set_duty_cycle_nolock(struct clk_core *core, |
|
struct clk_duty *duty) |
|
{ |
|
int ret; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
if (clk_core_rate_is_protected(core)) |
|
return -EBUSY; |
|
|
|
trace_clk_set_duty_cycle(core, duty); |
|
|
|
if (!core->ops->set_duty_cycle) |
|
return clk_core_set_duty_cycle_parent_nolock(core, duty); |
|
|
|
ret = core->ops->set_duty_cycle(core->hw, duty); |
|
if (!ret) |
|
memcpy(&core->duty, duty, sizeof(*duty)); |
|
|
|
trace_clk_set_duty_cycle_complete(core, duty); |
|
|
|
return ret; |
|
} |
|
|
|
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, |
|
struct clk_duty *duty) |
|
{ |
|
int ret = 0; |
|
|
|
if (core->parent && |
|
core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) { |
|
ret = clk_core_set_duty_cycle_nolock(core->parent, duty); |
|
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty)); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal |
|
* @clk: clock signal source |
|
* @num: numerator of the duty cycle ratio to be applied |
|
* @den: denominator of the duty cycle ratio to be applied |
|
* |
|
* Apply the duty cycle ratio if the ratio is valid and the clock can |
|
* perform this operation |
|
* |
|
* Returns (0) on success, a negative errno otherwise. |
|
*/ |
|
int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den) |
|
{ |
|
int ret; |
|
struct clk_duty duty; |
|
|
|
if (!clk) |
|
return 0; |
|
|
|
/* sanity check the ratio */ |
|
if (den == 0 || num > den) |
|
return -EINVAL; |
|
|
|
duty.num = num; |
|
duty.den = den; |
|
|
|
clk_prepare_lock(); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_unprotect(clk->core); |
|
|
|
ret = clk_core_set_duty_cycle_nolock(clk->core, &duty); |
|
|
|
if (clk->exclusive_count) |
|
clk_core_rate_protect(clk->core); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_set_duty_cycle); |
|
|
|
static int clk_core_get_scaled_duty_cycle(struct clk_core *core, |
|
unsigned int scale) |
|
{ |
|
struct clk_duty *duty = &core->duty; |
|
int ret; |
|
|
|
clk_prepare_lock(); |
|
|
|
ret = clk_core_update_duty_cycle_nolock(core); |
|
if (!ret) |
|
ret = mult_frac(scale, duty->num, duty->den); |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal |
|
* @clk: clock signal source |
|
* @scale: scaling factor to be applied to represent the ratio as an integer |
|
* |
|
* Returns the duty cycle ratio of a clock node multiplied by the provided |
|
* scaling factor, or negative errno on error. |
|
*/ |
|
int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale) |
|
{ |
|
if (!clk) |
|
return 0; |
|
|
|
return clk_core_get_scaled_duty_cycle(clk->core, scale); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle); |
|
|
|
/** |
|
* clk_is_match - check if two clk's point to the same hardware clock |
|
* @p: clk compared against q |
|
* @q: clk compared against p |
|
* |
|
* Returns true if the two struct clk pointers both point to the same hardware |
|
* clock node. Put differently, returns true if struct clk *p and struct clk *q |
|
* share the same struct clk_core object. |
|
* |
|
* Returns false otherwise. Note that two NULL clks are treated as matching. |
|
*/ |
|
bool clk_is_match(const struct clk *p, const struct clk *q) |
|
{ |
|
/* trivial case: identical struct clk's or both NULL */ |
|
if (p == q) |
|
return true; |
|
|
|
/* true if clk->core pointers match. Avoid dereferencing garbage */ |
|
if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q)) |
|
if (p->core == q->core) |
|
return true; |
|
|
|
return false; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_is_match); |
|
|
|
/*** debugfs support ***/ |
|
|
|
#ifdef CONFIG_DEBUG_FS |
|
#include <linux/debugfs.h> |
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|
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static struct dentry *rootdir; |
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static int inited = 0; |
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static DEFINE_MUTEX(clk_debug_lock); |
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static HLIST_HEAD(clk_debug_list); |
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|
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static struct hlist_head *orphan_list[] = { |
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&clk_orphan_list, |
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NULL, |
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}; |
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static void clk_summary_show_one(struct seq_file *s, struct clk_core *c, |
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int level) |
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{ |
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int phase; |
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seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ", |
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level * 3 + 1, "", |
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30 - level * 3, c->name, |
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c->enable_count, c->prepare_count, c->protect_count, |
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clk_core_get_rate_recalc(c), |
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clk_core_get_accuracy_recalc(c)); |
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phase = clk_core_get_phase(c); |
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if (phase >= 0) |
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seq_printf(s, "%5d", phase); |
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else |
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seq_puts(s, "-----"); |
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|
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seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000)); |
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if (c->ops->is_enabled) |
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seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N'); |
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else if (!c->ops->enable) |
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seq_printf(s, " %9c\n", 'Y'); |
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else |
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seq_printf(s, " %9c\n", '?'); |
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} |
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static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, |
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int level) |
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{ |
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struct clk_core *child; |
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|
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clk_pm_runtime_get(c); |
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clk_summary_show_one(s, c, level); |
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clk_pm_runtime_put(c); |
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hlist_for_each_entry(child, &c->children, child_node) |
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clk_summary_show_subtree(s, child, level + 1); |
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} |
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static int clk_summary_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *c; |
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struct hlist_head **lists = (struct hlist_head **)s->private; |
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|
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seq_puts(s, " enable prepare protect duty hardware\n"); |
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seq_puts(s, " clock count count count rate accuracy phase cycle enable\n"); |
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seq_puts(s, "-------------------------------------------------------------------------------------------------------\n"); |
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clk_prepare_lock(); |
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for (; *lists; lists++) |
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hlist_for_each_entry(c, *lists, child_node) |
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clk_summary_show_subtree(s, c, 0); |
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clk_prepare_unlock(); |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_summary); |
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static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level) |
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{ |
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int phase; |
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unsigned long min_rate, max_rate; |
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|
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clk_core_get_boundaries(c, &min_rate, &max_rate); |
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|
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/* This should be JSON format, i.e. elements separated with a comma */ |
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seq_printf(s, "\"%s\": { ", c->name); |
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seq_printf(s, "\"enable_count\": %d,", c->enable_count); |
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seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); |
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seq_printf(s, "\"protect_count\": %d,", c->protect_count); |
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seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c)); |
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seq_printf(s, "\"min_rate\": %lu,", min_rate); |
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seq_printf(s, "\"max_rate\": %lu,", max_rate); |
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seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c)); |
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phase = clk_core_get_phase(c); |
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if (phase >= 0) |
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seq_printf(s, "\"phase\": %d,", phase); |
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seq_printf(s, "\"duty_cycle\": %u", |
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clk_core_get_scaled_duty_cycle(c, 100000)); |
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} |
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static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level) |
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{ |
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struct clk_core *child; |
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clk_dump_one(s, c, level); |
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hlist_for_each_entry(child, &c->children, child_node) { |
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seq_putc(s, ','); |
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clk_dump_subtree(s, child, level + 1); |
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} |
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|
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seq_putc(s, '}'); |
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} |
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static int clk_dump_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *c; |
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bool first_node = true; |
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struct hlist_head **lists = (struct hlist_head **)s->private; |
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|
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seq_putc(s, '{'); |
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clk_prepare_lock(); |
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|
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for (; *lists; lists++) { |
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hlist_for_each_entry(c, *lists, child_node) { |
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if (!first_node) |
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seq_putc(s, ','); |
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first_node = false; |
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clk_dump_subtree(s, c, 0); |
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} |
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} |
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clk_prepare_unlock(); |
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seq_puts(s, "}\n"); |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_dump); |
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|
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#undef CLOCK_ALLOW_WRITE_DEBUGFS |
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#ifdef CLOCK_ALLOW_WRITE_DEBUGFS |
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/* |
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* This can be dangerous, therefore don't provide any real compile time |
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* configuration option for this feature. |
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* People who want to use this will need to modify the source code directly. |
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*/ |
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static int clk_rate_set(void *data, u64 val) |
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{ |
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struct clk_core *core = data; |
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int ret; |
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|
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clk_prepare_lock(); |
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ret = clk_core_set_rate_nolock(core, val); |
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clk_prepare_unlock(); |
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return ret; |
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} |
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#define clk_rate_mode 0644 |
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static int clk_prepare_enable_set(void *data, u64 val) |
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{ |
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struct clk_core *core = data; |
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int ret = 0; |
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if (val) |
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ret = clk_prepare_enable(core->hw->clk); |
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else |
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clk_disable_unprepare(core->hw->clk); |
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|
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return ret; |
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} |
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static int clk_prepare_enable_get(void *data, u64 *val) |
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{ |
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struct clk_core *core = data; |
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|
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*val = core->enable_count && core->prepare_count; |
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return 0; |
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} |
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DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get, |
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clk_prepare_enable_set, "%llu\n"); |
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#else |
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#define clk_rate_set NULL |
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#define clk_rate_mode 0444 |
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#endif |
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static int clk_rate_get(void *data, u64 *val) |
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{ |
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struct clk_core *core = data; |
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clk_prepare_lock(); |
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*val = clk_core_get_rate_recalc(core); |
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clk_prepare_unlock(); |
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return 0; |
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} |
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DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n"); |
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static const struct { |
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unsigned long flag; |
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const char *name; |
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} clk_flags[] = { |
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#define ENTRY(f) { f, #f } |
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ENTRY(CLK_SET_RATE_GATE), |
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ENTRY(CLK_SET_PARENT_GATE), |
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ENTRY(CLK_SET_RATE_PARENT), |
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ENTRY(CLK_IGNORE_UNUSED), |
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ENTRY(CLK_GET_RATE_NOCACHE), |
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ENTRY(CLK_SET_RATE_NO_REPARENT), |
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ENTRY(CLK_GET_ACCURACY_NOCACHE), |
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ENTRY(CLK_RECALC_NEW_RATES), |
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ENTRY(CLK_SET_RATE_UNGATE), |
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ENTRY(CLK_IS_CRITICAL), |
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ENTRY(CLK_OPS_PARENT_ENABLE), |
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ENTRY(CLK_DUTY_CYCLE_PARENT), |
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#undef ENTRY |
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}; |
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static int clk_flags_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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unsigned long flags = core->flags; |
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unsigned int i; |
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|
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for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) { |
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if (flags & clk_flags[i].flag) { |
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seq_printf(s, "%s\n", clk_flags[i].name); |
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flags &= ~clk_flags[i].flag; |
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} |
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} |
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if (flags) { |
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/* Unknown flags */ |
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seq_printf(s, "0x%lx\n", flags); |
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} |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_flags); |
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|
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static void possible_parent_show(struct seq_file *s, struct clk_core *core, |
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unsigned int i, char terminator) |
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{ |
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struct clk_core *parent; |
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|
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/* |
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* Go through the following options to fetch a parent's name. |
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* |
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* 1. Fetch the registered parent clock and use its name |
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* 2. Use the global (fallback) name if specified |
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* 3. Use the local fw_name if provided |
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* 4. Fetch parent clock's clock-output-name if DT index was set |
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* |
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* This may still fail in some cases, such as when the parent is |
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* specified directly via a struct clk_hw pointer, but it isn't |
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* registered (yet). |
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*/ |
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parent = clk_core_get_parent_by_index(core, i); |
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if (parent) |
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seq_puts(s, parent->name); |
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else if (core->parents[i].name) |
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seq_puts(s, core->parents[i].name); |
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else if (core->parents[i].fw_name) |
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seq_printf(s, "<%s>(fw)", core->parents[i].fw_name); |
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else if (core->parents[i].index >= 0) |
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seq_puts(s, |
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of_clk_get_parent_name(core->of_node, |
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core->parents[i].index)); |
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else |
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seq_puts(s, "(missing)"); |
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seq_putc(s, terminator); |
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} |
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static int possible_parents_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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int i; |
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for (i = 0; i < core->num_parents - 1; i++) |
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possible_parent_show(s, core, i, ' '); |
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possible_parent_show(s, core, i, '\n'); |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(possible_parents); |
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static int current_parent_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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if (core->parent) |
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seq_printf(s, "%s\n", core->parent->name); |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(current_parent); |
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#ifdef CLOCK_ALLOW_WRITE_DEBUGFS |
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static ssize_t current_parent_write(struct file *file, const char __user *ubuf, |
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size_t count, loff_t *ppos) |
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{ |
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struct seq_file *s = file->private_data; |
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struct clk_core *core = s->private; |
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struct clk_core *parent; |
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u8 idx; |
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int err; |
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err = kstrtou8_from_user(ubuf, count, 0, &idx); |
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if (err < 0) |
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return err; |
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parent = clk_core_get_parent_by_index(core, idx); |
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if (!parent) |
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return -ENOENT; |
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clk_prepare_lock(); |
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err = clk_core_set_parent_nolock(core, parent); |
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clk_prepare_unlock(); |
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if (err) |
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return err; |
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return count; |
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} |
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static const struct file_operations current_parent_rw_fops = { |
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.open = current_parent_open, |
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.write = current_parent_write, |
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.read = seq_read, |
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.llseek = seq_lseek, |
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.release = single_release, |
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}; |
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#endif |
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static int clk_duty_cycle_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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struct clk_duty *duty = &core->duty; |
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|
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seq_printf(s, "%u/%u\n", duty->num, duty->den); |
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle); |
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static int clk_min_rate_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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unsigned long min_rate, max_rate; |
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|
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clk_prepare_lock(); |
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clk_core_get_boundaries(core, &min_rate, &max_rate); |
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clk_prepare_unlock(); |
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seq_printf(s, "%lu\n", min_rate); |
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|
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_min_rate); |
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|
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static int clk_max_rate_show(struct seq_file *s, void *data) |
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{ |
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struct clk_core *core = s->private; |
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unsigned long min_rate, max_rate; |
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|
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clk_prepare_lock(); |
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clk_core_get_boundaries(core, &min_rate, &max_rate); |
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clk_prepare_unlock(); |
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seq_printf(s, "%lu\n", max_rate); |
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|
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return 0; |
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} |
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DEFINE_SHOW_ATTRIBUTE(clk_max_rate); |
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|
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static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) |
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{ |
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struct dentry *root; |
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|
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if (!core || !pdentry) |
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return; |
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|
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root = debugfs_create_dir(core->name, pdentry); |
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core->dentry = root; |
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debugfs_create_file("clk_rate", clk_rate_mode, root, core, |
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&clk_rate_fops); |
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debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops); |
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debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops); |
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debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy); |
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debugfs_create_u32("clk_phase", 0444, root, &core->phase); |
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debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops); |
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debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count); |
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debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count); |
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debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count); |
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debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count); |
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debugfs_create_file("clk_duty_cycle", 0444, root, core, |
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&clk_duty_cycle_fops); |
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#ifdef CLOCK_ALLOW_WRITE_DEBUGFS |
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debugfs_create_file("clk_prepare_enable", 0644, root, core, |
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&clk_prepare_enable_fops); |
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|
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if (core->num_parents > 1) |
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debugfs_create_file("clk_parent", 0644, root, core, |
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¤t_parent_rw_fops); |
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else |
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#endif |
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if (core->num_parents > 0) |
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debugfs_create_file("clk_parent", 0444, root, core, |
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¤t_parent_fops); |
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|
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if (core->num_parents > 1) |
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debugfs_create_file("clk_possible_parents", 0444, root, core, |
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&possible_parents_fops); |
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|
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if (core->ops->debug_init) |
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core->ops->debug_init(core->hw, core->dentry); |
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} |
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|
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/** |
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* clk_debug_register - add a clk node to the debugfs clk directory |
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* @core: the clk being added to the debugfs clk directory |
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* |
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* Dynamically adds a clk to the debugfs clk directory if debugfs has been |
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* initialized. Otherwise it bails out early since the debugfs clk directory |
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* will be created lazily by clk_debug_init as part of a late_initcall. |
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*/ |
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static void clk_debug_register(struct clk_core *core) |
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{ |
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mutex_lock(&clk_debug_lock); |
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hlist_add_head(&core->debug_node, &clk_debug_list); |
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if (inited) |
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clk_debug_create_one(core, rootdir); |
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mutex_unlock(&clk_debug_lock); |
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} |
|
|
|
/** |
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* clk_debug_unregister - remove a clk node from the debugfs clk directory |
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* @core: the clk being removed from the debugfs clk directory |
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* |
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* Dynamically removes a clk and all its child nodes from the |
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* debugfs clk directory if clk->dentry points to debugfs created by |
|
* clk_debug_register in __clk_core_init. |
|
*/ |
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static void clk_debug_unregister(struct clk_core *core) |
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{ |
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mutex_lock(&clk_debug_lock); |
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hlist_del_init(&core->debug_node); |
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debugfs_remove_recursive(core->dentry); |
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core->dentry = NULL; |
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mutex_unlock(&clk_debug_lock); |
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} |
|
|
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/** |
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* clk_debug_init - lazily populate the debugfs clk directory |
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* |
|
* clks are often initialized very early during boot before memory can be |
|
* dynamically allocated and well before debugfs is setup. This function |
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* populates the debugfs clk directory once at boot-time when we know that |
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* debugfs is setup. It should only be called once at boot-time, all other clks |
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* added dynamically will be done so with clk_debug_register. |
|
*/ |
|
static int __init clk_debug_init(void) |
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{ |
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struct clk_core *core; |
|
|
|
#ifdef CLOCK_ALLOW_WRITE_DEBUGFS |
|
pr_warn("\n"); |
|
pr_warn("********************************************************************\n"); |
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
|
pr_warn("** **\n"); |
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pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); |
|
pr_warn("** **\n"); |
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pr_warn("** This means that this kernel is built to expose clk operations **\n"); |
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pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n"); |
|
pr_warn("** to userspace, which may compromise security on your system. **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** If you see this message and you are not debugging the **\n"); |
|
pr_warn("** kernel, report this immediately to your vendor! **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
|
pr_warn("********************************************************************\n"); |
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#endif |
|
|
|
rootdir = debugfs_create_dir("clk", NULL); |
|
|
|
debugfs_create_file("clk_summary", 0444, rootdir, &all_lists, |
|
&clk_summary_fops); |
|
debugfs_create_file("clk_dump", 0444, rootdir, &all_lists, |
|
&clk_dump_fops); |
|
debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list, |
|
&clk_summary_fops); |
|
debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list, |
|
&clk_dump_fops); |
|
|
|
mutex_lock(&clk_debug_lock); |
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hlist_for_each_entry(core, &clk_debug_list, debug_node) |
|
clk_debug_create_one(core, rootdir); |
|
|
|
inited = 1; |
|
mutex_unlock(&clk_debug_lock); |
|
|
|
return 0; |
|
} |
|
late_initcall(clk_debug_init); |
|
#else |
|
static inline void clk_debug_register(struct clk_core *core) { } |
|
static inline void clk_debug_unregister(struct clk_core *core) |
|
{ |
|
} |
|
#endif |
|
|
|
static void clk_core_reparent_orphans_nolock(void) |
|
{ |
|
struct clk_core *orphan; |
|
struct hlist_node *tmp2; |
|
|
|
/* |
|
* walk the list of orphan clocks and reparent any that newly finds a |
|
* parent. |
|
*/ |
|
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
|
struct clk_core *parent = __clk_init_parent(orphan); |
|
|
|
/* |
|
* We need to use __clk_set_parent_before() and _after() to |
|
* properly migrate any prepare/enable count of the orphan |
|
* clock. This is important for CLK_IS_CRITICAL clocks, which |
|
* are enabled during init but might not have a parent yet. |
|
*/ |
|
if (parent) { |
|
/* update the clk tree topology */ |
|
__clk_set_parent_before(orphan, parent); |
|
__clk_set_parent_after(orphan, parent, NULL); |
|
__clk_recalc_accuracies(orphan); |
|
__clk_recalc_rates(orphan, true, 0); |
|
|
|
/* |
|
* __clk_init_parent() will set the initial req_rate to |
|
* 0 if the clock doesn't have clk_ops::recalc_rate and |
|
* is an orphan when it's registered. |
|
* |
|
* 'req_rate' is used by clk_set_rate_range() and |
|
* clk_put() to trigger a clk_set_rate() call whenever |
|
* the boundaries are modified. Let's make sure |
|
* 'req_rate' is set to something non-zero so that |
|
* clk_set_rate_range() doesn't drop the frequency. |
|
*/ |
|
orphan->req_rate = orphan->rate; |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* __clk_core_init - initialize the data structures in a struct clk_core |
|
* @core: clk_core being initialized |
|
* |
|
* Initializes the lists in struct clk_core, queries the hardware for the |
|
* parent and rate and sets them both. |
|
*/ |
|
static int __clk_core_init(struct clk_core *core) |
|
{ |
|
int ret; |
|
struct clk_core *parent; |
|
unsigned long rate; |
|
int phase; |
|
|
|
clk_prepare_lock(); |
|
|
|
/* |
|
* Set hw->core after grabbing the prepare_lock to synchronize with |
|
* callers of clk_core_fill_parent_index() where we treat hw->core |
|
* being NULL as the clk not being registered yet. This is crucial so |
|
* that clks aren't parented until their parent is fully registered. |
|
*/ |
|
core->hw->core = core; |
|
|
|
ret = clk_pm_runtime_get(core); |
|
if (ret) |
|
goto unlock; |
|
|
|
/* check to see if a clock with this name is already registered */ |
|
if (clk_core_lookup(core->name)) { |
|
pr_debug("%s: clk %s already initialized\n", |
|
__func__, core->name); |
|
ret = -EEXIST; |
|
goto out; |
|
} |
|
|
|
/* check that clk_ops are sane. See Documentation/driver-api/clk.rst */ |
|
if (core->ops->set_rate && |
|
!((core->ops->round_rate || core->ops->determine_rate) && |
|
core->ops->recalc_rate)) { |
|
pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", |
|
__func__, core->name); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (core->ops->set_parent && !core->ops->get_parent) { |
|
pr_err("%s: %s must implement .get_parent & .set_parent\n", |
|
__func__, core->name); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (core->num_parents > 1 && !core->ops->get_parent) { |
|
pr_err("%s: %s must implement .get_parent as it has multi parents\n", |
|
__func__, core->name); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (core->ops->set_rate_and_parent && |
|
!(core->ops->set_parent && core->ops->set_rate)) { |
|
pr_err("%s: %s must implement .set_parent & .set_rate\n", |
|
__func__, core->name); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* optional platform-specific magic |
|
* |
|
* The .init callback is not used by any of the basic clock types, but |
|
* exists for weird hardware that must perform initialization magic for |
|
* CCF to get an accurate view of clock for any other callbacks. It may |
|
* also be used needs to perform dynamic allocations. Such allocation |
|
* must be freed in the terminate() callback. |
|
* This callback shall not be used to initialize the parameters state, |
|
* such as rate, parent, etc ... |
|
* |
|
* If it exist, this callback should called before any other callback of |
|
* the clock |
|
*/ |
|
if (core->ops->init) { |
|
ret = core->ops->init(core->hw); |
|
if (ret) |
|
goto out; |
|
} |
|
|
|
parent = core->parent = __clk_init_parent(core); |
|
|
|
/* |
|
* Populate core->parent if parent has already been clk_core_init'd. If |
|
* parent has not yet been clk_core_init'd then place clk in the orphan |
|
* list. If clk doesn't have any parents then place it in the root |
|
* clk list. |
|
* |
|
* Every time a new clk is clk_init'd then we walk the list of orphan |
|
* clocks and re-parent any that are children of the clock currently |
|
* being clk_init'd. |
|
*/ |
|
if (parent) { |
|
hlist_add_head(&core->child_node, &parent->children); |
|
core->orphan = parent->orphan; |
|
} else if (!core->num_parents) { |
|
hlist_add_head(&core->child_node, &clk_root_list); |
|
core->orphan = false; |
|
} else { |
|
hlist_add_head(&core->child_node, &clk_orphan_list); |
|
core->orphan = true; |
|
} |
|
|
|
/* |
|
* Set clk's accuracy. The preferred method is to use |
|
* .recalc_accuracy. For simple clocks and lazy developers the default |
|
* fallback is to use the parent's accuracy. If a clock doesn't have a |
|
* parent (or is orphaned) then accuracy is set to zero (perfect |
|
* clock). |
|
*/ |
|
if (core->ops->recalc_accuracy) |
|
core->accuracy = core->ops->recalc_accuracy(core->hw, |
|
clk_core_get_accuracy_no_lock(parent)); |
|
else if (parent) |
|
core->accuracy = parent->accuracy; |
|
else |
|
core->accuracy = 0; |
|
|
|
/* |
|
* Set clk's phase by clk_core_get_phase() caching the phase. |
|
* Since a phase is by definition relative to its parent, just |
|
* query the current clock phase, or just assume it's in phase. |
|
*/ |
|
phase = clk_core_get_phase(core); |
|
if (phase < 0) { |
|
ret = phase; |
|
pr_warn("%s: Failed to get phase for clk '%s'\n", __func__, |
|
core->name); |
|
goto out; |
|
} |
|
|
|
/* |
|
* Set clk's duty cycle. |
|
*/ |
|
clk_core_update_duty_cycle_nolock(core); |
|
|
|
/* |
|
* Set clk's rate. The preferred method is to use .recalc_rate. For |
|
* simple clocks and lazy developers the default fallback is to use the |
|
* parent's rate. If a clock doesn't have a parent (or is orphaned) |
|
* then rate is set to zero. |
|
*/ |
|
if (core->ops->recalc_rate) |
|
rate = core->ops->recalc_rate(core->hw, |
|
clk_core_get_rate_nolock(parent)); |
|
else if (parent) |
|
rate = parent->rate; |
|
else |
|
rate = 0; |
|
core->rate = core->req_rate = rate; |
|
|
|
/* |
|
* Enable CLK_IS_CRITICAL clocks so newly added critical clocks |
|
* don't get accidentally disabled when walking the orphan tree and |
|
* reparenting clocks |
|
*/ |
|
if (core->flags & CLK_IS_CRITICAL) { |
|
ret = clk_core_prepare(core); |
|
if (ret) { |
|
pr_warn("%s: critical clk '%s' failed to prepare\n", |
|
__func__, core->name); |
|
goto out; |
|
} |
|
|
|
ret = clk_core_enable_lock(core); |
|
if (ret) { |
|
pr_warn("%s: critical clk '%s' failed to enable\n", |
|
__func__, core->name); |
|
clk_core_unprepare(core); |
|
goto out; |
|
} |
|
} |
|
|
|
clk_core_reparent_orphans_nolock(); |
|
|
|
kref_init(&core->ref); |
|
out: |
|
clk_pm_runtime_put(core); |
|
unlock: |
|
if (ret) { |
|
hlist_del_init(&core->child_node); |
|
core->hw->core = NULL; |
|
} |
|
|
|
clk_prepare_unlock(); |
|
|
|
if (!ret) |
|
clk_debug_register(core); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core |
|
* @core: clk to add consumer to |
|
* @clk: consumer to link to a clk |
|
*/ |
|
static void clk_core_link_consumer(struct clk_core *core, struct clk *clk) |
|
{ |
|
clk_prepare_lock(); |
|
hlist_add_head(&clk->clks_node, &core->clks); |
|
clk_prepare_unlock(); |
|
} |
|
|
|
/** |
|
* clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core |
|
* @clk: consumer to unlink |
|
*/ |
|
static void clk_core_unlink_consumer(struct clk *clk) |
|
{ |
|
lockdep_assert_held(&prepare_lock); |
|
hlist_del(&clk->clks_node); |
|
} |
|
|
|
/** |
|
* alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core |
|
* @core: clk to allocate a consumer for |
|
* @dev_id: string describing device name |
|
* @con_id: connection ID string on device |
|
* |
|
* Returns: clk consumer left unlinked from the consumer list |
|
*/ |
|
static struct clk *alloc_clk(struct clk_core *core, const char *dev_id, |
|
const char *con_id) |
|
{ |
|
struct clk *clk; |
|
|
|
clk = kzalloc(sizeof(*clk), GFP_KERNEL); |
|
if (!clk) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
clk->core = core; |
|
clk->dev_id = dev_id; |
|
clk->con_id = kstrdup_const(con_id, GFP_KERNEL); |
|
clk->max_rate = ULONG_MAX; |
|
|
|
return clk; |
|
} |
|
|
|
/** |
|
* free_clk - Free a clk consumer |
|
* @clk: clk consumer to free |
|
* |
|
* Note, this assumes the clk has been unlinked from the clk_core consumer |
|
* list. |
|
*/ |
|
static void free_clk(struct clk *clk) |
|
{ |
|
kfree_const(clk->con_id); |
|
kfree(clk); |
|
} |
|
|
|
/** |
|
* clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given |
|
* a clk_hw |
|
* @dev: clk consumer device |
|
* @hw: clk_hw associated with the clk being consumed |
|
* @dev_id: string describing device name |
|
* @con_id: connection ID string on device |
|
* |
|
* This is the main function used to create a clk pointer for use by clk |
|
* consumers. It connects a consumer to the clk_core and clk_hw structures |
|
* used by the framework and clk provider respectively. |
|
*/ |
|
struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw, |
|
const char *dev_id, const char *con_id) |
|
{ |
|
struct clk *clk; |
|
struct clk_core *core; |
|
|
|
/* This is to allow this function to be chained to others */ |
|
if (IS_ERR_OR_NULL(hw)) |
|
return ERR_CAST(hw); |
|
|
|
core = hw->core; |
|
clk = alloc_clk(core, dev_id, con_id); |
|
if (IS_ERR(clk)) |
|
return clk; |
|
clk->dev = dev; |
|
|
|
if (!try_module_get(core->owner)) { |
|
free_clk(clk); |
|
return ERR_PTR(-ENOENT); |
|
} |
|
|
|
kref_get(&core->ref); |
|
clk_core_link_consumer(core, clk); |
|
|
|
return clk; |
|
} |
|
|
|
/** |
|
* clk_hw_get_clk - get clk consumer given an clk_hw |
|
* @hw: clk_hw associated with the clk being consumed |
|
* @con_id: connection ID string on device |
|
* |
|
* Returns: new clk consumer |
|
* This is the function to be used by providers which need |
|
* to get a consumer clk and act on the clock element |
|
* Calls to this function must be balanced with calls clk_put() |
|
*/ |
|
struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id) |
|
{ |
|
struct device *dev = hw->core->dev; |
|
const char *name = dev ? dev_name(dev) : NULL; |
|
|
|
return clk_hw_create_clk(dev, hw, name, con_id); |
|
} |
|
EXPORT_SYMBOL(clk_hw_get_clk); |
|
|
|
static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist) |
|
{ |
|
const char *dst; |
|
|
|
if (!src) { |
|
if (must_exist) |
|
return -EINVAL; |
|
return 0; |
|
} |
|
|
|
*dst_p = dst = kstrdup_const(src, GFP_KERNEL); |
|
if (!dst) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
static int clk_core_populate_parent_map(struct clk_core *core, |
|
const struct clk_init_data *init) |
|
{ |
|
u8 num_parents = init->num_parents; |
|
const char * const *parent_names = init->parent_names; |
|
const struct clk_hw **parent_hws = init->parent_hws; |
|
const struct clk_parent_data *parent_data = init->parent_data; |
|
int i, ret = 0; |
|
struct clk_parent_map *parents, *parent; |
|
|
|
if (!num_parents) |
|
return 0; |
|
|
|
/* |
|
* Avoid unnecessary string look-ups of clk_core's possible parents by |
|
* having a cache of names/clk_hw pointers to clk_core pointers. |
|
*/ |
|
parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL); |
|
core->parents = parents; |
|
if (!parents) |
|
return -ENOMEM; |
|
|
|
/* Copy everything over because it might be __initdata */ |
|
for (i = 0, parent = parents; i < num_parents; i++, parent++) { |
|
parent->index = -1; |
|
if (parent_names) { |
|
/* throw a WARN if any entries are NULL */ |
|
WARN(!parent_names[i], |
|
"%s: invalid NULL in %s's .parent_names\n", |
|
__func__, core->name); |
|
ret = clk_cpy_name(&parent->name, parent_names[i], |
|
true); |
|
} else if (parent_data) { |
|
parent->hw = parent_data[i].hw; |
|
parent->index = parent_data[i].index; |
|
ret = clk_cpy_name(&parent->fw_name, |
|
parent_data[i].fw_name, false); |
|
if (!ret) |
|
ret = clk_cpy_name(&parent->name, |
|
parent_data[i].name, |
|
false); |
|
} else if (parent_hws) { |
|
parent->hw = parent_hws[i]; |
|
} else { |
|
ret = -EINVAL; |
|
WARN(1, "Must specify parents if num_parents > 0\n"); |
|
} |
|
|
|
if (ret) { |
|
do { |
|
kfree_const(parents[i].name); |
|
kfree_const(parents[i].fw_name); |
|
} while (--i >= 0); |
|
kfree(parents); |
|
|
|
return ret; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void clk_core_free_parent_map(struct clk_core *core) |
|
{ |
|
int i = core->num_parents; |
|
|
|
if (!core->num_parents) |
|
return; |
|
|
|
while (--i >= 0) { |
|
kfree_const(core->parents[i].name); |
|
kfree_const(core->parents[i].fw_name); |
|
} |
|
|
|
kfree(core->parents); |
|
} |
|
|
|
static struct clk * |
|
__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) |
|
{ |
|
int ret; |
|
struct clk_core *core; |
|
const struct clk_init_data *init = hw->init; |
|
|
|
/* |
|
* The init data is not supposed to be used outside of registration path. |
|
* Set it to NULL so that provider drivers can't use it either and so that |
|
* we catch use of hw->init early on in the core. |
|
*/ |
|
hw->init = NULL; |
|
|
|
core = kzalloc(sizeof(*core), GFP_KERNEL); |
|
if (!core) { |
|
ret = -ENOMEM; |
|
goto fail_out; |
|
} |
|
|
|
core->name = kstrdup_const(init->name, GFP_KERNEL); |
|
if (!core->name) { |
|
ret = -ENOMEM; |
|
goto fail_name; |
|
} |
|
|
|
if (WARN_ON(!init->ops)) { |
|
ret = -EINVAL; |
|
goto fail_ops; |
|
} |
|
core->ops = init->ops; |
|
|
|
if (dev && pm_runtime_enabled(dev)) |
|
core->rpm_enabled = true; |
|
core->dev = dev; |
|
core->of_node = np; |
|
if (dev && dev->driver) |
|
core->owner = dev->driver->owner; |
|
core->hw = hw; |
|
core->flags = init->flags; |
|
core->num_parents = init->num_parents; |
|
core->min_rate = 0; |
|
core->max_rate = ULONG_MAX; |
|
|
|
ret = clk_core_populate_parent_map(core, init); |
|
if (ret) |
|
goto fail_parents; |
|
|
|
INIT_HLIST_HEAD(&core->clks); |
|
|
|
/* |
|
* Don't call clk_hw_create_clk() here because that would pin the |
|
* provider module to itself and prevent it from ever being removed. |
|
*/ |
|
hw->clk = alloc_clk(core, NULL, NULL); |
|
if (IS_ERR(hw->clk)) { |
|
ret = PTR_ERR(hw->clk); |
|
goto fail_create_clk; |
|
} |
|
|
|
clk_core_link_consumer(core, hw->clk); |
|
|
|
ret = __clk_core_init(core); |
|
if (!ret) |
|
return hw->clk; |
|
|
|
clk_prepare_lock(); |
|
clk_core_unlink_consumer(hw->clk); |
|
clk_prepare_unlock(); |
|
|
|
free_clk(hw->clk); |
|
hw->clk = NULL; |
|
|
|
fail_create_clk: |
|
clk_core_free_parent_map(core); |
|
fail_parents: |
|
fail_ops: |
|
kfree_const(core->name); |
|
fail_name: |
|
kfree(core); |
|
fail_out: |
|
return ERR_PTR(ret); |
|
} |
|
|
|
/** |
|
* dev_or_parent_of_node() - Get device node of @dev or @dev's parent |
|
* @dev: Device to get device node of |
|
* |
|
* Return: device node pointer of @dev, or the device node pointer of |
|
* @dev->parent if dev doesn't have a device node, or NULL if neither |
|
* @dev or @dev->parent have a device node. |
|
*/ |
|
static struct device_node *dev_or_parent_of_node(struct device *dev) |
|
{ |
|
struct device_node *np; |
|
|
|
if (!dev) |
|
return NULL; |
|
|
|
np = dev_of_node(dev); |
|
if (!np) |
|
np = dev_of_node(dev->parent); |
|
|
|
return np; |
|
} |
|
|
|
/** |
|
* clk_register - allocate a new clock, register it and return an opaque cookie |
|
* @dev: device that is registering this clock |
|
* @hw: link to hardware-specific clock data |
|
* |
|
* clk_register is the *deprecated* interface for populating the clock tree with |
|
* new clock nodes. Use clk_hw_register() instead. |
|
* |
|
* Returns: a pointer to the newly allocated struct clk which |
|
* cannot be dereferenced by driver code but may be used in conjunction with the |
|
* rest of the clock API. In the event of an error clk_register will return an |
|
* error code; drivers must test for an error code after calling clk_register. |
|
*/ |
|
struct clk *clk_register(struct device *dev, struct clk_hw *hw) |
|
{ |
|
return __clk_register(dev, dev_or_parent_of_node(dev), hw); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_register); |
|
|
|
/** |
|
* clk_hw_register - register a clk_hw and return an error code |
|
* @dev: device that is registering this clock |
|
* @hw: link to hardware-specific clock data |
|
* |
|
* clk_hw_register is the primary interface for populating the clock tree with |
|
* new clock nodes. It returns an integer equal to zero indicating success or |
|
* less than zero indicating failure. Drivers must test for an error code after |
|
* calling clk_hw_register(). |
|
*/ |
|
int clk_hw_register(struct device *dev, struct clk_hw *hw) |
|
{ |
|
return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev), |
|
hw)); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_register); |
|
|
|
/* |
|
* of_clk_hw_register - register a clk_hw and return an error code |
|
* @node: device_node of device that is registering this clock |
|
* @hw: link to hardware-specific clock data |
|
* |
|
* of_clk_hw_register() is the primary interface for populating the clock tree |
|
* with new clock nodes when a struct device is not available, but a struct |
|
* device_node is. It returns an integer equal to zero indicating success or |
|
* less than zero indicating failure. Drivers must test for an error code after |
|
* calling of_clk_hw_register(). |
|
*/ |
|
int of_clk_hw_register(struct device_node *node, struct clk_hw *hw) |
|
{ |
|
return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw)); |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_hw_register); |
|
|
|
/* Free memory allocated for a clock. */ |
|
static void __clk_release(struct kref *ref) |
|
{ |
|
struct clk_core *core = container_of(ref, struct clk_core, ref); |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
clk_core_free_parent_map(core); |
|
kfree_const(core->name); |
|
kfree(core); |
|
} |
|
|
|
/* |
|
* Empty clk_ops for unregistered clocks. These are used temporarily |
|
* after clk_unregister() was called on a clock and until last clock |
|
* consumer calls clk_put() and the struct clk object is freed. |
|
*/ |
|
static int clk_nodrv_prepare_enable(struct clk_hw *hw) |
|
{ |
|
return -ENXIO; |
|
} |
|
|
|
static void clk_nodrv_disable_unprepare(struct clk_hw *hw) |
|
{ |
|
WARN_ON_ONCE(1); |
|
} |
|
|
|
static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, |
|
unsigned long parent_rate) |
|
{ |
|
return -ENXIO; |
|
} |
|
|
|
static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) |
|
{ |
|
return -ENXIO; |
|
} |
|
|
|
static const struct clk_ops clk_nodrv_ops = { |
|
.enable = clk_nodrv_prepare_enable, |
|
.disable = clk_nodrv_disable_unprepare, |
|
.prepare = clk_nodrv_prepare_enable, |
|
.unprepare = clk_nodrv_disable_unprepare, |
|
.set_rate = clk_nodrv_set_rate, |
|
.set_parent = clk_nodrv_set_parent, |
|
}; |
|
|
|
static void clk_core_evict_parent_cache_subtree(struct clk_core *root, |
|
const struct clk_core *target) |
|
{ |
|
int i; |
|
struct clk_core *child; |
|
|
|
for (i = 0; i < root->num_parents; i++) |
|
if (root->parents[i].core == target) |
|
root->parents[i].core = NULL; |
|
|
|
hlist_for_each_entry(child, &root->children, child_node) |
|
clk_core_evict_parent_cache_subtree(child, target); |
|
} |
|
|
|
/* Remove this clk from all parent caches */ |
|
static void clk_core_evict_parent_cache(struct clk_core *core) |
|
{ |
|
const struct hlist_head **lists; |
|
struct clk_core *root; |
|
|
|
lockdep_assert_held(&prepare_lock); |
|
|
|
for (lists = all_lists; *lists; lists++) |
|
hlist_for_each_entry(root, *lists, child_node) |
|
clk_core_evict_parent_cache_subtree(root, core); |
|
|
|
} |
|
|
|
/** |
|
* clk_unregister - unregister a currently registered clock |
|
* @clk: clock to unregister |
|
*/ |
|
void clk_unregister(struct clk *clk) |
|
{ |
|
unsigned long flags; |
|
const struct clk_ops *ops; |
|
|
|
if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
|
return; |
|
|
|
clk_debug_unregister(clk->core); |
|
|
|
clk_prepare_lock(); |
|
|
|
ops = clk->core->ops; |
|
if (ops == &clk_nodrv_ops) { |
|
pr_err("%s: unregistered clock: %s\n", __func__, |
|
clk->core->name); |
|
goto unlock; |
|
} |
|
/* |
|
* Assign empty clock ops for consumers that might still hold |
|
* a reference to this clock. |
|
*/ |
|
flags = clk_enable_lock(); |
|
clk->core->ops = &clk_nodrv_ops; |
|
clk_enable_unlock(flags); |
|
|
|
if (ops->terminate) |
|
ops->terminate(clk->core->hw); |
|
|
|
if (!hlist_empty(&clk->core->children)) { |
|
struct clk_core *child; |
|
struct hlist_node *t; |
|
|
|
/* Reparent all children to the orphan list. */ |
|
hlist_for_each_entry_safe(child, t, &clk->core->children, |
|
child_node) |
|
clk_core_set_parent_nolock(child, NULL); |
|
} |
|
|
|
clk_core_evict_parent_cache(clk->core); |
|
|
|
hlist_del_init(&clk->core->child_node); |
|
|
|
if (clk->core->prepare_count) |
|
pr_warn("%s: unregistering prepared clock: %s\n", |
|
__func__, clk->core->name); |
|
|
|
if (clk->core->protect_count) |
|
pr_warn("%s: unregistering protected clock: %s\n", |
|
__func__, clk->core->name); |
|
|
|
kref_put(&clk->core->ref, __clk_release); |
|
free_clk(clk); |
|
unlock: |
|
clk_prepare_unlock(); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_unregister); |
|
|
|
/** |
|
* clk_hw_unregister - unregister a currently registered clk_hw |
|
* @hw: hardware-specific clock data to unregister |
|
*/ |
|
void clk_hw_unregister(struct clk_hw *hw) |
|
{ |
|
clk_unregister(hw->clk); |
|
} |
|
EXPORT_SYMBOL_GPL(clk_hw_unregister); |
|
|
|
static void devm_clk_unregister_cb(struct device *dev, void *res) |
|
{ |
|
clk_unregister(*(struct clk **)res); |
|
} |
|
|
|
static void devm_clk_hw_unregister_cb(struct device *dev, void *res) |
|
{ |
|
clk_hw_unregister(*(struct clk_hw **)res); |
|
} |
|
|
|
/** |
|
* devm_clk_register - resource managed clk_register() |
|
* @dev: device that is registering this clock |
|
* @hw: link to hardware-specific clock data |
|
* |
|
* Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead. |
|
* |
|
* Clocks returned from this function are automatically clk_unregister()ed on |
|
* driver detach. See clk_register() for more information. |
|
*/ |
|
struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) |
|
{ |
|
struct clk *clk; |
|
struct clk **clkp; |
|
|
|
clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL); |
|
if (!clkp) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
clk = clk_register(dev, hw); |
|
if (!IS_ERR(clk)) { |
|
*clkp = clk; |
|
devres_add(dev, clkp); |
|
} else { |
|
devres_free(clkp); |
|
} |
|
|
|
return clk; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_clk_register); |
|
|
|
/** |
|
* devm_clk_hw_register - resource managed clk_hw_register() |
|
* @dev: device that is registering this clock |
|
* @hw: link to hardware-specific clock data |
|
* |
|
* Managed clk_hw_register(). Clocks registered by this function are |
|
* automatically clk_hw_unregister()ed on driver detach. See clk_hw_register() |
|
* for more information. |
|
*/ |
|
int devm_clk_hw_register(struct device *dev, struct clk_hw *hw) |
|
{ |
|
struct clk_hw **hwp; |
|
int ret; |
|
|
|
hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL); |
|
if (!hwp) |
|
return -ENOMEM; |
|
|
|
ret = clk_hw_register(dev, hw); |
|
if (!ret) { |
|
*hwp = hw; |
|
devres_add(dev, hwp); |
|
} else { |
|
devres_free(hwp); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_clk_hw_register); |
|
|
|
static void devm_clk_release(struct device *dev, void *res) |
|
{ |
|
clk_put(*(struct clk **)res); |
|
} |
|
|
|
/** |
|
* devm_clk_hw_get_clk - resource managed clk_hw_get_clk() |
|
* @dev: device that is registering this clock |
|
* @hw: clk_hw associated with the clk being consumed |
|
* @con_id: connection ID string on device |
|
* |
|
* Managed clk_hw_get_clk(). Clocks got with this function are |
|
* automatically clk_put() on driver detach. See clk_put() |
|
* for more information. |
|
*/ |
|
struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw, |
|
const char *con_id) |
|
{ |
|
struct clk *clk; |
|
struct clk **clkp; |
|
|
|
/* This should not happen because it would mean we have drivers |
|
* passing around clk_hw pointers instead of having the caller use |
|
* proper clk_get() style APIs |
|
*/ |
|
WARN_ON_ONCE(dev != hw->core->dev); |
|
|
|
clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
|
if (!clkp) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
clk = clk_hw_get_clk(hw, con_id); |
|
if (!IS_ERR(clk)) { |
|
*clkp = clk; |
|
devres_add(dev, clkp); |
|
} else { |
|
devres_free(clkp); |
|
} |
|
|
|
return clk; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk); |
|
|
|
/* |
|
* clkdev helpers |
|
*/ |
|
|
|
void __clk_put(struct clk *clk) |
|
{ |
|
struct module *owner; |
|
|
|
if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
|
return; |
|
|
|
clk_prepare_lock(); |
|
|
|
/* |
|
* Before calling clk_put, all calls to clk_rate_exclusive_get() from a |
|
* given user should be balanced with calls to clk_rate_exclusive_put() |
|
* and by that same consumer |
|
*/ |
|
if (WARN_ON(clk->exclusive_count)) { |
|
/* We voiced our concern, let's sanitize the situation */ |
|
clk->core->protect_count -= (clk->exclusive_count - 1); |
|
clk_core_rate_unprotect(clk->core); |
|
clk->exclusive_count = 0; |
|
} |
|
|
|
hlist_del(&clk->clks_node); |
|
|
|
/* If we had any boundaries on that clock, let's drop them. */ |
|
if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX) |
|
clk_set_rate_range_nolock(clk, 0, ULONG_MAX); |
|
|
|
owner = clk->core->owner; |
|
kref_put(&clk->core->ref, __clk_release); |
|
|
|
clk_prepare_unlock(); |
|
|
|
module_put(owner); |
|
|
|
free_clk(clk); |
|
} |
|
|
|
/*** clk rate change notifiers ***/ |
|
|
|
/** |
|
* clk_notifier_register - add a clk rate change notifier |
|
* @clk: struct clk * to watch |
|
* @nb: struct notifier_block * with callback info |
|
* |
|
* Request notification when clk's rate changes. This uses an SRCU |
|
* notifier because we want it to block and notifier unregistrations are |
|
* uncommon. The callbacks associated with the notifier must not |
|
* re-enter into the clk framework by calling any top-level clk APIs; |
|
* this will cause a nested prepare_lock mutex. |
|
* |
|
* In all notification cases (pre, post and abort rate change) the original |
|
* clock rate is passed to the callback via struct clk_notifier_data.old_rate |
|
* and the new frequency is passed via struct clk_notifier_data.new_rate. |
|
* |
|
* clk_notifier_register() must be called from non-atomic context. |
|
* Returns -EINVAL if called with null arguments, -ENOMEM upon |
|
* allocation failure; otherwise, passes along the return value of |
|
* srcu_notifier_chain_register(). |
|
*/ |
|
int clk_notifier_register(struct clk *clk, struct notifier_block *nb) |
|
{ |
|
struct clk_notifier *cn; |
|
int ret = -ENOMEM; |
|
|
|
if (!clk || !nb) |
|
return -EINVAL; |
|
|
|
clk_prepare_lock(); |
|
|
|
/* search the list of notifiers for this clk */ |
|
list_for_each_entry(cn, &clk_notifier_list, node) |
|
if (cn->clk == clk) |
|
goto found; |
|
|
|
/* if clk wasn't in the notifier list, allocate new clk_notifier */ |
|
cn = kzalloc(sizeof(*cn), GFP_KERNEL); |
|
if (!cn) |
|
goto out; |
|
|
|
cn->clk = clk; |
|
srcu_init_notifier_head(&cn->notifier_head); |
|
|
|
list_add(&cn->node, &clk_notifier_list); |
|
|
|
found: |
|
ret = srcu_notifier_chain_register(&cn->notifier_head, nb); |
|
|
|
clk->core->notifier_count++; |
|
|
|
out: |
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_notifier_register); |
|
|
|
/** |
|
* clk_notifier_unregister - remove a clk rate change notifier |
|
* @clk: struct clk * |
|
* @nb: struct notifier_block * with callback info |
|
* |
|
* Request no further notification for changes to 'clk' and frees memory |
|
* allocated in clk_notifier_register. |
|
* |
|
* Returns -EINVAL if called with null arguments; otherwise, passes |
|
* along the return value of srcu_notifier_chain_unregister(). |
|
*/ |
|
int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) |
|
{ |
|
struct clk_notifier *cn; |
|
int ret = -ENOENT; |
|
|
|
if (!clk || !nb) |
|
return -EINVAL; |
|
|
|
clk_prepare_lock(); |
|
|
|
list_for_each_entry(cn, &clk_notifier_list, node) { |
|
if (cn->clk == clk) { |
|
ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); |
|
|
|
clk->core->notifier_count--; |
|
|
|
/* XXX the notifier code should handle this better */ |
|
if (!cn->notifier_head.head) { |
|
srcu_cleanup_notifier_head(&cn->notifier_head); |
|
list_del(&cn->node); |
|
kfree(cn); |
|
} |
|
break; |
|
} |
|
} |
|
|
|
clk_prepare_unlock(); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(clk_notifier_unregister); |
|
|
|
struct clk_notifier_devres { |
|
struct clk *clk; |
|
struct notifier_block *nb; |
|
}; |
|
|
|
static void devm_clk_notifier_release(struct device *dev, void *res) |
|
{ |
|
struct clk_notifier_devres *devres = res; |
|
|
|
clk_notifier_unregister(devres->clk, devres->nb); |
|
} |
|
|
|
int devm_clk_notifier_register(struct device *dev, struct clk *clk, |
|
struct notifier_block *nb) |
|
{ |
|
struct clk_notifier_devres *devres; |
|
int ret; |
|
|
|
devres = devres_alloc(devm_clk_notifier_release, |
|
sizeof(*devres), GFP_KERNEL); |
|
|
|
if (!devres) |
|
return -ENOMEM; |
|
|
|
ret = clk_notifier_register(clk, nb); |
|
if (!ret) { |
|
devres->clk = clk; |
|
devres->nb = nb; |
|
} else { |
|
devres_free(devres); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_clk_notifier_register); |
|
|
|
#ifdef CONFIG_OF |
|
static void clk_core_reparent_orphans(void) |
|
{ |
|
clk_prepare_lock(); |
|
clk_core_reparent_orphans_nolock(); |
|
clk_prepare_unlock(); |
|
} |
|
|
|
/** |
|
* struct of_clk_provider - Clock provider registration structure |
|
* @link: Entry in global list of clock providers |
|
* @node: Pointer to device tree node of clock provider |
|
* @get: Get clock callback. Returns NULL or a struct clk for the |
|
* given clock specifier |
|
* @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a |
|
* struct clk_hw for the given clock specifier |
|
* @data: context pointer to be passed into @get callback |
|
*/ |
|
struct of_clk_provider { |
|
struct list_head link; |
|
|
|
struct device_node *node; |
|
struct clk *(*get)(struct of_phandle_args *clkspec, void *data); |
|
struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data); |
|
void *data; |
|
}; |
|
|
|
extern struct of_device_id __clk_of_table; |
|
static const struct of_device_id __clk_of_table_sentinel |
|
__used __section("__clk_of_table_end"); |
|
|
|
static LIST_HEAD(of_clk_providers); |
|
static DEFINE_MUTEX(of_clk_mutex); |
|
|
|
struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, |
|
void *data) |
|
{ |
|
return data; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_src_simple_get); |
|
|
|
struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data) |
|
{ |
|
return data; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_hw_simple_get); |
|
|
|
struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
|
{ |
|
struct clk_onecell_data *clk_data = data; |
|
unsigned int idx = clkspec->args[0]; |
|
|
|
if (idx >= clk_data->clk_num) { |
|
pr_err("%s: invalid clock index %u\n", __func__, idx); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
return clk_data->clks[idx]; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); |
|
|
|
struct clk_hw * |
|
of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data) |
|
{ |
|
struct clk_hw_onecell_data *hw_data = data; |
|
unsigned int idx = clkspec->args[0]; |
|
|
|
if (idx >= hw_data->num) { |
|
pr_err("%s: invalid index %u\n", __func__, idx); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
return hw_data->hws[idx]; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get); |
|
|
|
/** |
|
* of_clk_add_provider() - Register a clock provider for a node |
|
* @np: Device node pointer associated with clock provider |
|
* @clk_src_get: callback for decoding clock |
|
* @data: context pointer for @clk_src_get callback. |
|
* |
|
* This function is *deprecated*. Use of_clk_add_hw_provider() instead. |
|
*/ |
|
int of_clk_add_provider(struct device_node *np, |
|
struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, |
|
void *data), |
|
void *data) |
|
{ |
|
struct of_clk_provider *cp; |
|
int ret; |
|
|
|
if (!np) |
|
return 0; |
|
|
|
cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
|
if (!cp) |
|
return -ENOMEM; |
|
|
|
cp->node = of_node_get(np); |
|
cp->data = data; |
|
cp->get = clk_src_get; |
|
|
|
mutex_lock(&of_clk_mutex); |
|
list_add(&cp->link, &of_clk_providers); |
|
mutex_unlock(&of_clk_mutex); |
|
pr_debug("Added clock from %pOF\n", np); |
|
|
|
clk_core_reparent_orphans(); |
|
|
|
ret = of_clk_set_defaults(np, true); |
|
if (ret < 0) |
|
of_clk_del_provider(np); |
|
|
|
fwnode_dev_initialized(&np->fwnode, true); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_add_provider); |
|
|
|
/** |
|
* of_clk_add_hw_provider() - Register a clock provider for a node |
|
* @np: Device node pointer associated with clock provider |
|
* @get: callback for decoding clk_hw |
|
* @data: context pointer for @get callback. |
|
*/ |
|
int of_clk_add_hw_provider(struct device_node *np, |
|
struct clk_hw *(*get)(struct of_phandle_args *clkspec, |
|
void *data), |
|
void *data) |
|
{ |
|
struct of_clk_provider *cp; |
|
int ret; |
|
|
|
if (!np) |
|
return 0; |
|
|
|
cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
|
if (!cp) |
|
return -ENOMEM; |
|
|
|
cp->node = of_node_get(np); |
|
cp->data = data; |
|
cp->get_hw = get; |
|
|
|
mutex_lock(&of_clk_mutex); |
|
list_add(&cp->link, &of_clk_providers); |
|
mutex_unlock(&of_clk_mutex); |
|
pr_debug("Added clk_hw provider from %pOF\n", np); |
|
|
|
clk_core_reparent_orphans(); |
|
|
|
ret = of_clk_set_defaults(np, true); |
|
if (ret < 0) |
|
of_clk_del_provider(np); |
|
|
|
fwnode_dev_initialized(&np->fwnode, true); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_add_hw_provider); |
|
|
|
static void devm_of_clk_release_provider(struct device *dev, void *res) |
|
{ |
|
of_clk_del_provider(*(struct device_node **)res); |
|
} |
|
|
|
/* |
|
* We allow a child device to use its parent device as the clock provider node |
|
* for cases like MFD sub-devices where the child device driver wants to use |
|
* devm_*() APIs but not list the device in DT as a sub-node. |
|
*/ |
|
static struct device_node *get_clk_provider_node(struct device *dev) |
|
{ |
|
struct device_node *np, *parent_np; |
|
|
|
np = dev->of_node; |
|
parent_np = dev->parent ? dev->parent->of_node : NULL; |
|
|
|
if (!of_find_property(np, "#clock-cells", NULL)) |
|
if (of_find_property(parent_np, "#clock-cells", NULL)) |
|
np = parent_np; |
|
|
|
return np; |
|
} |
|
|
|
/** |
|
* devm_of_clk_add_hw_provider() - Managed clk provider node registration |
|
* @dev: Device acting as the clock provider (used for DT node and lifetime) |
|
* @get: callback for decoding clk_hw |
|
* @data: context pointer for @get callback |
|
* |
|
* Registers clock provider for given device's node. If the device has no DT |
|
* node or if the device node lacks of clock provider information (#clock-cells) |
|
* then the parent device's node is scanned for this information. If parent node |
|
* has the #clock-cells then it is used in registration. Provider is |
|
* automatically released at device exit. |
|
* |
|
* Return: 0 on success or an errno on failure. |
|
*/ |
|
int devm_of_clk_add_hw_provider(struct device *dev, |
|
struct clk_hw *(*get)(struct of_phandle_args *clkspec, |
|
void *data), |
|
void *data) |
|
{ |
|
struct device_node **ptr, *np; |
|
int ret; |
|
|
|
ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr), |
|
GFP_KERNEL); |
|
if (!ptr) |
|
return -ENOMEM; |
|
|
|
np = get_clk_provider_node(dev); |
|
ret = of_clk_add_hw_provider(np, get, data); |
|
if (!ret) { |
|
*ptr = np; |
|
devres_add(dev, ptr); |
|
} else { |
|
devres_free(ptr); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider); |
|
|
|
/** |
|
* of_clk_del_provider() - Remove a previously registered clock provider |
|
* @np: Device node pointer associated with clock provider |
|
*/ |
|
void of_clk_del_provider(struct device_node *np) |
|
{ |
|
struct of_clk_provider *cp; |
|
|
|
if (!np) |
|
return; |
|
|
|
mutex_lock(&of_clk_mutex); |
|
list_for_each_entry(cp, &of_clk_providers, link) { |
|
if (cp->node == np) { |
|
list_del(&cp->link); |
|
fwnode_dev_initialized(&np->fwnode, false); |
|
of_node_put(cp->node); |
|
kfree(cp); |
|
break; |
|
} |
|
} |
|
mutex_unlock(&of_clk_mutex); |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_del_provider); |
|
|
|
/** |
|
* of_parse_clkspec() - Parse a DT clock specifier for a given device node |
|
* @np: device node to parse clock specifier from |
|
* @index: index of phandle to parse clock out of. If index < 0, @name is used |
|
* @name: clock name to find and parse. If name is NULL, the index is used |
|
* @out_args: Result of parsing the clock specifier |
|
* |
|
* Parses a device node's "clocks" and "clock-names" properties to find the |
|
* phandle and cells for the index or name that is desired. The resulting clock |
|
* specifier is placed into @out_args, or an errno is returned when there's a |
|
* parsing error. The @index argument is ignored if @name is non-NULL. |
|
* |
|
* Example: |
|
* |
|
* phandle1: clock-controller@1 { |
|
* #clock-cells = <2>; |
|
* } |
|
* |
|
* phandle2: clock-controller@2 { |
|
* #clock-cells = <1>; |
|
* } |
|
* |
|
* clock-consumer@3 { |
|
* clocks = <&phandle1 1 2 &phandle2 3>; |
|
* clock-names = "name1", "name2"; |
|
* } |
|
* |
|
* To get a device_node for `clock-controller@2' node you may call this |
|
* function a few different ways: |
|
* |
|
* of_parse_clkspec(clock-consumer@3, -1, "name2", &args); |
|
* of_parse_clkspec(clock-consumer@3, 1, NULL, &args); |
|
* of_parse_clkspec(clock-consumer@3, 1, "name2", &args); |
|
* |
|
* Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT |
|
* if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in |
|
* the "clock-names" property of @np. |
|
*/ |
|
static int of_parse_clkspec(const struct device_node *np, int index, |
|
const char *name, struct of_phandle_args *out_args) |
|
{ |
|
int ret = -ENOENT; |
|
|
|
/* Walk up the tree of devices looking for a clock property that matches */ |
|
while (np) { |
|
/* |
|
* For named clocks, first look up the name in the |
|
* "clock-names" property. If it cannot be found, then index |
|
* will be an error code and of_parse_phandle_with_args() will |
|
* return -EINVAL. |
|
*/ |
|
if (name) |
|
index = of_property_match_string(np, "clock-names", name); |
|
ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells", |
|
index, out_args); |
|
if (!ret) |
|
break; |
|
if (name && index >= 0) |
|
break; |
|
|
|
/* |
|
* No matching clock found on this node. If the parent node |
|
* has a "clock-ranges" property, then we can try one of its |
|
* clocks. |
|
*/ |
|
np = np->parent; |
|
if (np && !of_get_property(np, "clock-ranges", NULL)) |
|
break; |
|
index = 0; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static struct clk_hw * |
|
__of_clk_get_hw_from_provider(struct of_clk_provider *provider, |
|
struct of_phandle_args *clkspec) |
|
{ |
|
struct clk *clk; |
|
|
|
if (provider->get_hw) |
|
return provider->get_hw(clkspec, provider->data); |
|
|
|
clk = provider->get(clkspec, provider->data); |
|
if (IS_ERR(clk)) |
|
return ERR_CAST(clk); |
|
return __clk_get_hw(clk); |
|
} |
|
|
|
static struct clk_hw * |
|
of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) |
|
{ |
|
struct of_clk_provider *provider; |
|
struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER); |
|
|
|
if (!clkspec) |
|
return ERR_PTR(-EINVAL); |
|
|
|
mutex_lock(&of_clk_mutex); |
|
list_for_each_entry(provider, &of_clk_providers, link) { |
|
if (provider->node == clkspec->np) { |
|
hw = __of_clk_get_hw_from_provider(provider, clkspec); |
|
if (!IS_ERR(hw)) |
|
break; |
|
} |
|
} |
|
mutex_unlock(&of_clk_mutex); |
|
|
|
return hw; |
|
} |
|
|
|
/** |
|
* of_clk_get_from_provider() - Lookup a clock from a clock provider |
|
* @clkspec: pointer to a clock specifier data structure |
|
* |
|
* This function looks up a struct clk from the registered list of clock |
|
* providers, an input is a clock specifier data structure as returned |
|
* from the of_parse_phandle_with_args() function call. |
|
*/ |
|
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) |
|
{ |
|
struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec); |
|
|
|
return clk_hw_create_clk(NULL, hw, NULL, __func__); |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_get_from_provider); |
|
|
|
struct clk_hw *of_clk_get_hw(struct device_node *np, int index, |
|
const char *con_id) |
|
{ |
|
int ret; |
|
struct clk_hw *hw; |
|
struct of_phandle_args clkspec; |
|
|
|
ret = of_parse_clkspec(np, index, con_id, &clkspec); |
|
if (ret) |
|
return ERR_PTR(ret); |
|
|
|
hw = of_clk_get_hw_from_clkspec(&clkspec); |
|
of_node_put(clkspec.np); |
|
|
|
return hw; |
|
} |
|
|
|
static struct clk *__of_clk_get(struct device_node *np, |
|
int index, const char *dev_id, |
|
const char *con_id) |
|
{ |
|
struct clk_hw *hw = of_clk_get_hw(np, index, con_id); |
|
|
|
return clk_hw_create_clk(NULL, hw, dev_id, con_id); |
|
} |
|
|
|
struct clk *of_clk_get(struct device_node *np, int index) |
|
{ |
|
return __of_clk_get(np, index, np->full_name, NULL); |
|
} |
|
EXPORT_SYMBOL(of_clk_get); |
|
|
|
/** |
|
* of_clk_get_by_name() - Parse and lookup a clock referenced by a device node |
|
* @np: pointer to clock consumer node |
|
* @name: name of consumer's clock input, or NULL for the first clock reference |
|
* |
|
* This function parses the clocks and clock-names properties, |
|
* and uses them to look up the struct clk from the registered list of clock |
|
* providers. |
|
*/ |
|
struct clk *of_clk_get_by_name(struct device_node *np, const char *name) |
|
{ |
|
if (!np) |
|
return ERR_PTR(-ENOENT); |
|
|
|
return __of_clk_get(np, 0, np->full_name, name); |
|
} |
|
EXPORT_SYMBOL(of_clk_get_by_name); |
|
|
|
/** |
|
* of_clk_get_parent_count() - Count the number of clocks a device node has |
|
* @np: device node to count |
|
* |
|
* Returns: The number of clocks that are possible parents of this node |
|
*/ |
|
unsigned int of_clk_get_parent_count(const struct device_node *np) |
|
{ |
|
int count; |
|
|
|
count = of_count_phandle_with_args(np, "clocks", "#clock-cells"); |
|
if (count < 0) |
|
return 0; |
|
|
|
return count; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_get_parent_count); |
|
|
|
const char *of_clk_get_parent_name(const struct device_node *np, int index) |
|
{ |
|
struct of_phandle_args clkspec; |
|
struct property *prop; |
|
const char *clk_name; |
|
const __be32 *vp; |
|
u32 pv; |
|
int rc; |
|
int count; |
|
struct clk *clk; |
|
|
|
rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, |
|
&clkspec); |
|
if (rc) |
|
return NULL; |
|
|
|
index = clkspec.args_count ? clkspec.args[0] : 0; |
|
count = 0; |
|
|
|
/* if there is an indices property, use it to transfer the index |
|
* specified into an array offset for the clock-output-names property. |
|
*/ |
|
of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { |
|
if (index == pv) { |
|
index = count; |
|
break; |
|
} |
|
count++; |
|
} |
|
/* We went off the end of 'clock-indices' without finding it */ |
|
if (prop && !vp) |
|
return NULL; |
|
|
|
if (of_property_read_string_index(clkspec.np, "clock-output-names", |
|
index, |
|
&clk_name) < 0) { |
|
/* |
|
* Best effort to get the name if the clock has been |
|
* registered with the framework. If the clock isn't |
|
* registered, we return the node name as the name of |
|
* the clock as long as #clock-cells = 0. |
|
*/ |
|
clk = of_clk_get_from_provider(&clkspec); |
|
if (IS_ERR(clk)) { |
|
if (clkspec.args_count == 0) |
|
clk_name = clkspec.np->name; |
|
else |
|
clk_name = NULL; |
|
} else { |
|
clk_name = __clk_get_name(clk); |
|
clk_put(clk); |
|
} |
|
} |
|
|
|
|
|
of_node_put(clkspec.np); |
|
return clk_name; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_get_parent_name); |
|
|
|
/** |
|
* of_clk_parent_fill() - Fill @parents with names of @np's parents and return |
|
* number of parents |
|
* @np: Device node pointer associated with clock provider |
|
* @parents: pointer to char array that hold the parents' names |
|
* @size: size of the @parents array |
|
* |
|
* Return: number of parents for the clock node. |
|
*/ |
|
int of_clk_parent_fill(struct device_node *np, const char **parents, |
|
unsigned int size) |
|
{ |
|
unsigned int i = 0; |
|
|
|
while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL) |
|
i++; |
|
|
|
return i; |
|
} |
|
EXPORT_SYMBOL_GPL(of_clk_parent_fill); |
|
|
|
struct clock_provider { |
|
void (*clk_init_cb)(struct device_node *); |
|
struct device_node *np; |
|
struct list_head node; |
|
}; |
|
|
|
/* |
|
* This function looks for a parent clock. If there is one, then it |
|
* checks that the provider for this parent clock was initialized, in |
|
* this case the parent clock will be ready. |
|
*/ |
|
static int parent_ready(struct device_node *np) |
|
{ |
|
int i = 0; |
|
|
|
while (true) { |
|
struct clk *clk = of_clk_get(np, i); |
|
|
|
/* this parent is ready we can check the next one */ |
|
if (!IS_ERR(clk)) { |
|
clk_put(clk); |
|
i++; |
|
continue; |
|
} |
|
|
|
/* at least one parent is not ready, we exit now */ |
|
if (PTR_ERR(clk) == -EPROBE_DEFER) |
|
return 0; |
|
|
|
/* |
|
* Here we make assumption that the device tree is |
|
* written correctly. So an error means that there is |
|
* no more parent. As we didn't exit yet, then the |
|
* previous parent are ready. If there is no clock |
|
* parent, no need to wait for them, then we can |
|
* consider their absence as being ready |
|
*/ |
|
return 1; |
|
} |
|
} |
|
|
|
/** |
|
* of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree |
|
* @np: Device node pointer associated with clock provider |
|
* @index: clock index |
|
* @flags: pointer to top-level framework flags |
|
* |
|
* Detects if the clock-critical property exists and, if so, sets the |
|
* corresponding CLK_IS_CRITICAL flag. |
|
* |
|
* Do not use this function. It exists only for legacy Device Tree |
|
* bindings, such as the one-clock-per-node style that are outdated. |
|
* Those bindings typically put all clock data into .dts and the Linux |
|
* driver has no clock data, thus making it impossible to set this flag |
|
* correctly from the driver. Only those drivers may call |
|
* of_clk_detect_critical from their setup functions. |
|
* |
|
* Return: error code or zero on success |
|
*/ |
|
int of_clk_detect_critical(struct device_node *np, int index, |
|
unsigned long *flags) |
|
{ |
|
struct property *prop; |
|
const __be32 *cur; |
|
uint32_t idx; |
|
|
|
if (!np || !flags) |
|
return -EINVAL; |
|
|
|
of_property_for_each_u32(np, "clock-critical", prop, cur, idx) |
|
if (index == idx) |
|
*flags |= CLK_IS_CRITICAL; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* of_clk_init() - Scan and init clock providers from the DT |
|
* @matches: array of compatible values and init functions for providers. |
|
* |
|
* This function scans the device tree for matching clock providers |
|
* and calls their initialization functions. It also does it by trying |
|
* to follow the dependencies. |
|
*/ |
|
void __init of_clk_init(const struct of_device_id *matches) |
|
{ |
|
const struct of_device_id *match; |
|
struct device_node *np; |
|
struct clock_provider *clk_provider, *next; |
|
bool is_init_done; |
|
bool force = false; |
|
LIST_HEAD(clk_provider_list); |
|
|
|
if (!matches) |
|
matches = &__clk_of_table; |
|
|
|
/* First prepare the list of the clocks providers */ |
|
for_each_matching_node_and_match(np, matches, &match) { |
|
struct clock_provider *parent; |
|
|
|
if (!of_device_is_available(np)) |
|
continue; |
|
|
|
parent = kzalloc(sizeof(*parent), GFP_KERNEL); |
|
if (!parent) { |
|
list_for_each_entry_safe(clk_provider, next, |
|
&clk_provider_list, node) { |
|
list_del(&clk_provider->node); |
|
of_node_put(clk_provider->np); |
|
kfree(clk_provider); |
|
} |
|
of_node_put(np); |
|
return; |
|
} |
|
|
|
parent->clk_init_cb = match->data; |
|
parent->np = of_node_get(np); |
|
list_add_tail(&parent->node, &clk_provider_list); |
|
} |
|
|
|
while (!list_empty(&clk_provider_list)) { |
|
is_init_done = false; |
|
list_for_each_entry_safe(clk_provider, next, |
|
&clk_provider_list, node) { |
|
if (force || parent_ready(clk_provider->np)) { |
|
|
|
/* Don't populate platform devices */ |
|
of_node_set_flag(clk_provider->np, |
|
OF_POPULATED); |
|
|
|
clk_provider->clk_init_cb(clk_provider->np); |
|
of_clk_set_defaults(clk_provider->np, true); |
|
|
|
list_del(&clk_provider->node); |
|
of_node_put(clk_provider->np); |
|
kfree(clk_provider); |
|
is_init_done = true; |
|
} |
|
} |
|
|
|
/* |
|
* We didn't manage to initialize any of the |
|
* remaining providers during the last loop, so now we |
|
* initialize all the remaining ones unconditionally |
|
* in case the clock parent was not mandatory |
|
*/ |
|
if (!is_init_done) |
|
force = true; |
|
} |
|
} |
|
#endif
|
|
|