forked from Minki/linux
1c63c1c089
Under certain circumstances, some specific operations must be done with the device node pointer, which forces the timer code to propagate the pointer to the functions which need it. In order to consolidate the function signatures in the different drivers by using the timer-of structure, let's store it in the timer-of structure as a handy pointer when it is needed. Tested-by: Benjamin Gaignard <benjamin.gaignard@st.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Benjamin Gaignard <benjamin.gaignard@st.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1515418139-23276-9-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
238 lines
5.7 KiB
C
238 lines
5.7 KiB
C
/*
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* Copyright (c) 2017, Linaro Ltd. All rights reserved.
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*
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* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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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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of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
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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 %s\n",
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of_irq->name, np->full_name);
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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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pr_err("Failed to get clock for %pOF\n", np);
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return PTR_ERR(of_clk->clk);
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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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const char *name = of_base->name ? of_base->name : np->full_name;
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of_base->base = of_io_request_and_map(np, of_base->index, name);
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if (IS_ERR(of_base->base)) {
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pr_err("Failed to iomap (%s)\n", 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->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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