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/*
* Copyright (c) 2017, Linaro Ltd. All rights reserved.
*
* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#include "timer-of.h"
/**
* timer_of_irq_exit - Release the interrupt
* @of_irq: an of_timer_irq structure pointer
*
* Free the irq resource
*/
static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
{
struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
struct clock_event_device *clkevt = &to->clkevt;
of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
free_irq(of_irq->irq, clkevt);
}
/**
* timer_of_irq_init - Request the interrupt
* @np: a device tree node pointer
* @of_irq: an of_timer_irq structure pointer
*
* Get the interrupt number from the DT from its definition and
* request it. The interrupt is gotten by falling back the following way:
*
* - Get interrupt number by name
* - Get interrupt number by index
*
* When the interrupt is per CPU, 'request_percpu_irq()' is called,
* otherwise 'request_irq()' is used.
*
* Returns 0 on success, < 0 otherwise
*/
static __init int timer_of_irq_init(struct device_node *np,
struct of_timer_irq *of_irq)
{
int ret;
struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
struct clock_event_device *clkevt = &to->clkevt;
if (of_irq->name) {
of_irq->irq = ret = of_irq_get_byname(np, of_irq->name);
if (ret < 0) {
pr_err("Failed to get interrupt %s for %s\n",
of_irq->name, np->full_name);
return ret;
}
} else {
of_irq->irq = irq_of_parse_and_map(np, of_irq->index);
}
if (!of_irq->irq) {
pr_err("Failed to map interrupt for %pOF\n", np);
return -EINVAL;
}
ret = of_irq->percpu ?
request_percpu_irq(of_irq->irq, of_irq->handler,
np->full_name, clkevt) :
request_irq(of_irq->irq, of_irq->handler,
of_irq->flags ? of_irq->flags : IRQF_TIMER,
np->full_name, clkevt);
if (ret) {
pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np);
return ret;
}
clkevt->irq = of_irq->irq;
return 0;
}
/**
* timer_of_clk_exit - Release the clock resources
* @of_clk: a of_timer_clk structure pointer
*
* Disables and releases the refcount on the clk
*/
static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
{
of_clk->rate = 0;
clk_disable_unprepare(of_clk->clk);
clk_put(of_clk->clk);
}
/**
* timer_of_clk_init - Initialize the clock resources
* @np: a device tree node pointer
* @of_clk: a of_timer_clk structure pointer
*
* Get the clock by name or by index, enable it and get the rate
*
* Returns 0 on success, < 0 otherwise
*/
static __init int timer_of_clk_init(struct device_node *np,
struct of_timer_clk *of_clk)
{
int ret;
of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
of_clk_get(np, of_clk->index);
if (IS_ERR(of_clk->clk)) {
pr_err("Failed to get clock for %pOF\n", np);
return PTR_ERR(of_clk->clk);
}
ret = clk_prepare_enable(of_clk->clk);
if (ret) {
pr_err("Failed for enable clock for %pOF\n", np);
goto out_clk_put;
}
of_clk->rate = clk_get_rate(of_clk->clk);
if (!of_clk->rate) {
ret = -EINVAL;
pr_err("Failed to get clock rate for %pOF\n", np);
goto out_clk_disable;
}
of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ);
out:
return ret;
out_clk_disable:
clk_disable_unprepare(of_clk->clk);
out_clk_put:
clk_put(of_clk->clk);
goto out;
}
static __init void timer_of_base_exit(struct of_timer_base *of_base)
{
iounmap(of_base->base);
}
static __init int timer_of_base_init(struct device_node *np,
struct of_timer_base *of_base)
{
const char *name = of_base->name ? of_base->name : np->full_name;
of_base->base = of_io_request_and_map(np, of_base->index, name);
if (IS_ERR(of_base->base)) {
pr_err("Failed to iomap (%s)\n", name);
return PTR_ERR(of_base->base);
}
return 0;
}
int __init timer_of_init(struct device_node *np, struct timer_of *to)
{
int ret = -EINVAL;
int flags = 0;
if (to->flags & TIMER_OF_BASE) {
ret = timer_of_base_init(np, &to->of_base);
if (ret)
goto out_fail;
flags |= TIMER_OF_BASE;
}
if (to->flags & TIMER_OF_CLOCK) {
ret = timer_of_clk_init(np, &to->of_clk);
if (ret)
goto out_fail;
flags |= TIMER_OF_CLOCK;
}
if (to->flags & TIMER_OF_IRQ) {
ret = timer_of_irq_init(np, &to->of_irq);
if (ret)
goto out_fail;
flags |= TIMER_OF_IRQ;
}
if (!to->clkevt.name)
to->clkevt.name = np->name;
to->np = np;
return ret;
out_fail:
if (flags & TIMER_OF_IRQ)
timer_of_irq_exit(&to->of_irq);
if (flags & TIMER_OF_CLOCK)
timer_of_clk_exit(&to->of_clk);
if (flags & TIMER_OF_BASE)
timer_of_base_exit(&to->of_base);
return ret;
}
/**
* timer_of_cleanup - release timer_of ressources
* @to: timer_of structure
*
* Release the ressources that has been used in timer_of_init().
* This function should be called in init error cases
*/
void __init timer_of_cleanup(struct timer_of *to)
{
if (to->flags & TIMER_OF_IRQ)
timer_of_irq_exit(&to->of_irq);
if (to->flags & TIMER_OF_CLOCK)
timer_of_clk_exit(&to->of_clk);
if (to->flags & TIMER_OF_BASE)
timer_of_base_exit(&to->of_base);
}
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