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/* herring-watchdog.c
*
* Copyright (C) 2010 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that 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.
*
*/
#include <plat/regs-watchdog.h>
#include <mach/map.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/io.h>
/* reset timeout in PCLK/256/128 (~2048:1s) */
static unsigned watchdog_reset = (30 * 2048);
/* pet timeout in jiffies */
static unsigned watchdog_pet = (10 * HZ);
static struct workqueue_struct *watchdog_wq;
static void watchdog_workfunc(struct work_struct *work);
static DECLARE_DELAYED_WORK(watchdog_work, watchdog_workfunc);
static void watchdog_workfunc(struct work_struct *work)
{
writel(watchdog_reset, S3C2410_WTCNT);
queue_delayed_work(watchdog_wq, &watchdog_work, watchdog_pet);
}
static void watchdog_start(void)
{
unsigned int val;
/* set to PCLK / 256 / 128 */
val = S3C2410_WTCON_DIV128;
val |= S3C2410_WTCON_PRESCALE(255);
writel(val, S3C2410_WTCON);
/* program initial count */
writel(watchdog_reset, S3C2410_WTCNT);
writel(watchdog_reset, S3C2410_WTDAT);
/* start timer */
val |= S3C2410_WTCON_RSTEN | S3C2410_WTCON_ENABLE;
writel(val, S3C2410_WTCON);
/* make sure we're ready to pet the dog */
queue_delayed_work(watchdog_wq, &watchdog_work, watchdog_pet);
}
static void watchdog_stop(void)
{
writel(0, S3C2410_WTCON);
}
static int watchdog_probe(struct platform_device *pdev)
{
watchdog_wq = alloc_workqueue("pet_watchdog",
WQ_UNBOUND | WQ_HIGHPRI, 1);
watchdog_start();
return 0;
}
static int watchdog_suspend(struct device *dev)
{
watchdog_stop();
return 0;
}
static int watchdog_resume(struct device *dev)
{
watchdog_start();
return 0;
}
static struct dev_pm_ops watchdog_pm_ops = {
.suspend_noirq = watchdog_suspend,
.resume_noirq = watchdog_resume,
};
static struct platform_driver watchdog_driver = {
.probe = watchdog_probe,
.driver = {
.owner = THIS_MODULE,
.name = "watchdog",
.pm = &watchdog_pm_ops,
},
};
static int __init watchdog_init(void)
{
return platform_driver_register(&watchdog_driver);
}
module_init(watchdog_init);
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