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220 lines
5.2 KiB
220 lines
5.2 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 Mike Turquette, Linaro Ltd <[email protected]> |
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* |
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* Fixed rate clock implementation |
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*/ |
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#include <linux/clk-provider.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/io.h> |
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#include <linux/err.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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/* |
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* DOC: basic fixed-rate clock that cannot gate |
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* |
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* Traits of this clock: |
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* prepare - clk_(un)prepare only ensures parents are prepared |
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* enable - clk_enable only ensures parents are enabled |
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* rate - rate is always a fixed value. No clk_set_rate support |
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* parent - fixed parent. No clk_set_parent support |
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*/ |
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#define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw) |
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static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw, |
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unsigned long parent_rate) |
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{ |
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return to_clk_fixed_rate(hw)->fixed_rate; |
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} |
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static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw, |
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unsigned long parent_accuracy) |
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{ |
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struct clk_fixed_rate *fixed = to_clk_fixed_rate(hw); |
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if (fixed->flags & CLK_FIXED_RATE_PARENT_ACCURACY) |
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return parent_accuracy; |
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return fixed->fixed_accuracy; |
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} |
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const struct clk_ops clk_fixed_rate_ops = { |
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.recalc_rate = clk_fixed_rate_recalc_rate, |
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.recalc_accuracy = clk_fixed_rate_recalc_accuracy, |
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}; |
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EXPORT_SYMBOL_GPL(clk_fixed_rate_ops); |
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struct clk_hw *__clk_hw_register_fixed_rate(struct device *dev, |
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struct device_node *np, const char *name, |
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const char *parent_name, const struct clk_hw *parent_hw, |
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const struct clk_parent_data *parent_data, unsigned long flags, |
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unsigned long fixed_rate, unsigned long fixed_accuracy, |
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unsigned long clk_fixed_flags) |
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{ |
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struct clk_fixed_rate *fixed; |
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struct clk_hw *hw; |
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struct clk_init_data init = {}; |
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int ret = -EINVAL; |
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/* allocate fixed-rate clock */ |
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fixed = kzalloc(sizeof(*fixed), GFP_KERNEL); |
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if (!fixed) |
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return ERR_PTR(-ENOMEM); |
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init.name = name; |
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init.ops = &clk_fixed_rate_ops; |
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init.flags = flags; |
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init.parent_names = parent_name ? &parent_name : NULL; |
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init.parent_hws = parent_hw ? &parent_hw : NULL; |
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init.parent_data = parent_data; |
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if (parent_name || parent_hw || parent_data) |
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init.num_parents = 1; |
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else |
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init.num_parents = 0; |
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/* struct clk_fixed_rate assignments */ |
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fixed->flags = clk_fixed_flags; |
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fixed->fixed_rate = fixed_rate; |
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fixed->fixed_accuracy = fixed_accuracy; |
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fixed->hw.init = &init; |
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/* register the clock */ |
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hw = &fixed->hw; |
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if (dev || !np) |
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ret = clk_hw_register(dev, hw); |
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else if (np) |
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ret = of_clk_hw_register(np, hw); |
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if (ret) { |
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kfree(fixed); |
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hw = ERR_PTR(ret); |
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} |
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return hw; |
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} |
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EXPORT_SYMBOL_GPL(__clk_hw_register_fixed_rate); |
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struct clk *clk_register_fixed_rate(struct device *dev, const char *name, |
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const char *parent_name, unsigned long flags, |
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unsigned long fixed_rate) |
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{ |
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struct clk_hw *hw; |
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hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name, |
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flags, fixed_rate, 0); |
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if (IS_ERR(hw)) |
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return ERR_CAST(hw); |
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return hw->clk; |
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} |
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EXPORT_SYMBOL_GPL(clk_register_fixed_rate); |
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void clk_unregister_fixed_rate(struct clk *clk) |
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{ |
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struct clk_hw *hw; |
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hw = __clk_get_hw(clk); |
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if (!hw) |
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return; |
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clk_unregister(clk); |
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kfree(to_clk_fixed_rate(hw)); |
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} |
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EXPORT_SYMBOL_GPL(clk_unregister_fixed_rate); |
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void clk_hw_unregister_fixed_rate(struct clk_hw *hw) |
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{ |
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struct clk_fixed_rate *fixed; |
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fixed = to_clk_fixed_rate(hw); |
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clk_hw_unregister(hw); |
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kfree(fixed); |
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} |
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EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_rate); |
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#ifdef CONFIG_OF |
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static struct clk_hw *_of_fixed_clk_setup(struct device_node *node) |
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{ |
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struct clk_hw *hw; |
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const char *clk_name = node->name; |
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u32 rate; |
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u32 accuracy = 0; |
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int ret; |
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if (of_property_read_u32(node, "clock-frequency", &rate)) |
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return ERR_PTR(-EIO); |
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of_property_read_u32(node, "clock-accuracy", &accuracy); |
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of_property_read_string(node, "clock-output-names", &clk_name); |
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hw = clk_hw_register_fixed_rate_with_accuracy(NULL, clk_name, NULL, |
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0, rate, accuracy); |
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if (IS_ERR(hw)) |
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return hw; |
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ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw); |
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if (ret) { |
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clk_hw_unregister_fixed_rate(hw); |
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return ERR_PTR(ret); |
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} |
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return hw; |
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} |
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/** |
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* of_fixed_clk_setup() - Setup function for simple fixed rate clock |
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* @node: device node for the clock |
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*/ |
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void __init of_fixed_clk_setup(struct device_node *node) |
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{ |
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_of_fixed_clk_setup(node); |
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} |
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CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup); |
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static int of_fixed_clk_remove(struct platform_device *pdev) |
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{ |
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struct clk_hw *hw = platform_get_drvdata(pdev); |
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of_clk_del_provider(pdev->dev.of_node); |
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clk_hw_unregister_fixed_rate(hw); |
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return 0; |
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} |
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static int of_fixed_clk_probe(struct platform_device *pdev) |
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{ |
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struct clk_hw *hw; |
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/* |
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* This function is not executed when of_fixed_clk_setup |
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* succeeded. |
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*/ |
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hw = _of_fixed_clk_setup(pdev->dev.of_node); |
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if (IS_ERR(hw)) |
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return PTR_ERR(hw); |
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platform_set_drvdata(pdev, hw); |
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return 0; |
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} |
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static const struct of_device_id of_fixed_clk_ids[] = { |
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{ .compatible = "fixed-clock" }, |
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{ } |
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}; |
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static struct platform_driver of_fixed_clk_driver = { |
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.driver = { |
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.name = "of_fixed_clk", |
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.of_match_table = of_fixed_clk_ids, |
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}, |
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.probe = of_fixed_clk_probe, |
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.remove = of_fixed_clk_remove, |
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}; |
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builtin_platform_driver(of_fixed_clk_driver); |
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#endif
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