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230 lines
5.2 KiB
230 lines
5.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2017, Linaro Ltd. All rights reserved. |
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* |
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* Author: Daniel Lezcano <[email protected]> |
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*/ |
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#include <linux/clk.h> |
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#include <linux/interrupt.h> |
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#include <linux/of.h> |
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#include <linux/of_address.h> |
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#include <linux/of_irq.h> |
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#include <linux/slab.h> |
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#include "timer-of.h" |
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/** |
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* timer_of_irq_exit - Release the interrupt |
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* @of_irq: an of_timer_irq structure pointer |
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* |
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* Free the irq resource |
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*/ |
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static __init void timer_of_irq_exit(struct of_timer_irq *of_irq) |
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{ |
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struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); |
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struct clock_event_device *clkevt = &to->clkevt; |
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if (of_irq->percpu) |
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free_percpu_irq(of_irq->irq, clkevt); |
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else |
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free_irq(of_irq->irq, clkevt); |
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} |
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/** |
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* timer_of_irq_init - Request the interrupt |
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* @np: a device tree node pointer |
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* @of_irq: an of_timer_irq structure pointer |
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* |
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* Get the interrupt number from the DT from its definition and |
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* request it. The interrupt is gotten by falling back the following way: |
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* |
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* - Get interrupt number by name |
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* - Get interrupt number by index |
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* |
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* When the interrupt is per CPU, 'request_percpu_irq()' is called, |
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* otherwise 'request_irq()' is used. |
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* |
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* Returns 0 on success, < 0 otherwise |
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*/ |
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static __init int timer_of_irq_init(struct device_node *np, |
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struct of_timer_irq *of_irq) |
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{ |
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int ret; |
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struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); |
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struct clock_event_device *clkevt = &to->clkevt; |
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if (of_irq->name) { |
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of_irq->irq = ret = of_irq_get_byname(np, of_irq->name); |
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if (ret < 0) { |
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pr_err("Failed to get interrupt %s for %pOF\n", |
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of_irq->name, np); |
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return ret; |
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} |
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} else { |
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of_irq->irq = irq_of_parse_and_map(np, of_irq->index); |
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} |
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if (!of_irq->irq) { |
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pr_err("Failed to map interrupt for %pOF\n", np); |
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return -EINVAL; |
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} |
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ret = of_irq->percpu ? |
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request_percpu_irq(of_irq->irq, of_irq->handler, |
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np->full_name, clkevt) : |
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request_irq(of_irq->irq, of_irq->handler, |
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of_irq->flags ? of_irq->flags : IRQF_TIMER, |
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np->full_name, clkevt); |
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if (ret) { |
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pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np); |
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return ret; |
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} |
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clkevt->irq = of_irq->irq; |
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return 0; |
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} |
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/** |
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* timer_of_clk_exit - Release the clock resources |
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* @of_clk: a of_timer_clk structure pointer |
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* |
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* Disables and releases the refcount on the clk |
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*/ |
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static __init void timer_of_clk_exit(struct of_timer_clk *of_clk) |
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{ |
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of_clk->rate = 0; |
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clk_disable_unprepare(of_clk->clk); |
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clk_put(of_clk->clk); |
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} |
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/** |
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* timer_of_clk_init - Initialize the clock resources |
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* @np: a device tree node pointer |
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* @of_clk: a of_timer_clk structure pointer |
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* |
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* Get the clock by name or by index, enable it and get the rate |
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* |
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* Returns 0 on success, < 0 otherwise |
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*/ |
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static __init int timer_of_clk_init(struct device_node *np, |
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struct of_timer_clk *of_clk) |
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{ |
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int ret; |
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of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : |
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of_clk_get(np, of_clk->index); |
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if (IS_ERR(of_clk->clk)) { |
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ret = PTR_ERR(of_clk->clk); |
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if (ret != -EPROBE_DEFER) |
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pr_err("Failed to get clock for %pOF\n", np); |
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goto out; |
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} |
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ret = clk_prepare_enable(of_clk->clk); |
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if (ret) { |
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pr_err("Failed for enable clock for %pOF\n", np); |
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goto out_clk_put; |
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} |
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of_clk->rate = clk_get_rate(of_clk->clk); |
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if (!of_clk->rate) { |
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ret = -EINVAL; |
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pr_err("Failed to get clock rate for %pOF\n", np); |
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goto out_clk_disable; |
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} |
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of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); |
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out: |
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return ret; |
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out_clk_disable: |
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clk_disable_unprepare(of_clk->clk); |
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out_clk_put: |
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clk_put(of_clk->clk); |
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goto out; |
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} |
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static __init void timer_of_base_exit(struct of_timer_base *of_base) |
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{ |
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iounmap(of_base->base); |
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} |
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static __init int timer_of_base_init(struct device_node *np, |
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struct of_timer_base *of_base) |
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{ |
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of_base->base = of_base->name ? |
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of_io_request_and_map(np, of_base->index, of_base->name) : |
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of_iomap(np, of_base->index); |
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if (IS_ERR(of_base->base)) { |
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pr_err("Failed to iomap (%s)\n", of_base->name); |
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return PTR_ERR(of_base->base); |
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} |
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return 0; |
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} |
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int __init timer_of_init(struct device_node *np, struct timer_of *to) |
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{ |
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int ret = -EINVAL; |
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int flags = 0; |
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if (to->flags & TIMER_OF_BASE) { |
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ret = timer_of_base_init(np, &to->of_base); |
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if (ret) |
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goto out_fail; |
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flags |= TIMER_OF_BASE; |
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} |
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if (to->flags & TIMER_OF_CLOCK) { |
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ret = timer_of_clk_init(np, &to->of_clk); |
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if (ret) |
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goto out_fail; |
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flags |= TIMER_OF_CLOCK; |
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} |
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if (to->flags & TIMER_OF_IRQ) { |
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ret = timer_of_irq_init(np, &to->of_irq); |
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if (ret) |
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goto out_fail; |
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flags |= TIMER_OF_IRQ; |
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} |
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if (!to->clkevt.name) |
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to->clkevt.name = np->full_name; |
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to->np = np; |
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return ret; |
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out_fail: |
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if (flags & TIMER_OF_IRQ) |
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timer_of_irq_exit(&to->of_irq); |
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if (flags & TIMER_OF_CLOCK) |
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timer_of_clk_exit(&to->of_clk); |
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if (flags & TIMER_OF_BASE) |
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timer_of_base_exit(&to->of_base); |
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return ret; |
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} |
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/** |
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* timer_of_cleanup - release timer_of ressources |
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* @to: timer_of structure |
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* |
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* Release the ressources that has been used in timer_of_init(). |
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* This function should be called in init error cases |
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*/ |
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void __init timer_of_cleanup(struct timer_of *to) |
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{ |
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if (to->flags & TIMER_OF_IRQ) |
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timer_of_irq_exit(&to->of_irq); |
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if (to->flags & TIMER_OF_CLOCK) |
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timer_of_clk_exit(&to->of_clk); |
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if (to->flags & TIMER_OF_BASE) |
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timer_of_base_exit(&to->of_base); |
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}
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