mirror of https://gitee.com/openkylin/linux.git
289 lines
6.5 KiB
C
289 lines
6.5 KiB
C
/*
|
|
* Watchdog driver for Atmel AT91RM9200 (Thunder)
|
|
*
|
|
* Copyright (C) 2003 SAN People (Pty) Ltd
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/types.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/uaccess.h>
|
|
#include <mach/at91_st.h>
|
|
|
|
#define WDT_DEFAULT_TIME 5 /* seconds */
|
|
#define WDT_MAX_TIME 256 /* seconds */
|
|
|
|
static int wdt_time = WDT_DEFAULT_TIME;
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
module_param(wdt_time, int, 0);
|
|
MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
|
|
__MODULE_STRING(WDT_DEFAULT_TIME) ")");
|
|
|
|
#ifdef CONFIG_WATCHDOG_NOWAYOUT
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
#endif
|
|
|
|
|
|
static unsigned long at91wdt_busy;
|
|
|
|
/* ......................................................................... */
|
|
|
|
/*
|
|
* Disable the watchdog.
|
|
*/
|
|
static inline void at91_wdt_stop(void)
|
|
{
|
|
at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN);
|
|
}
|
|
|
|
/*
|
|
* Enable and reset the watchdog.
|
|
*/
|
|
static inline void at91_wdt_start(void)
|
|
{
|
|
at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
|
|
(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
|
|
at91_sys_write(AT91_ST_CR, AT91_ST_WDRST);
|
|
}
|
|
|
|
/*
|
|
* Reload the watchdog timer. (ie, pat the watchdog)
|
|
*/
|
|
static inline void at91_wdt_reload(void)
|
|
{
|
|
at91_sys_write(AT91_ST_CR, AT91_ST_WDRST);
|
|
}
|
|
|
|
/* ......................................................................... */
|
|
|
|
/*
|
|
* Watchdog device is opened, and watchdog starts running.
|
|
*/
|
|
static int at91_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(0, &at91wdt_busy))
|
|
return -EBUSY;
|
|
|
|
at91_wdt_start();
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
/*
|
|
* Close the watchdog device.
|
|
* If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
|
|
* disabled.
|
|
*/
|
|
static int at91_wdt_close(struct inode *inode, struct file *file)
|
|
{
|
|
/* Disable the watchdog when file is closed */
|
|
if (!nowayout)
|
|
at91_wdt_stop();
|
|
|
|
clear_bit(0, &at91wdt_busy);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Change the watchdog time interval.
|
|
*/
|
|
static int at91_wdt_settimeout(int new_time)
|
|
{
|
|
/*
|
|
* All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz
|
|
*
|
|
* Since WDV is a 16-bit counter, the maximum period is
|
|
* 65536 / 0.256 = 256 seconds.
|
|
*/
|
|
if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
|
|
return -EINVAL;
|
|
|
|
/* Set new watchdog time. It will be used when
|
|
at91_wdt_start() is called. */
|
|
wdt_time = new_time;
|
|
return 0;
|
|
}
|
|
|
|
static struct watchdog_info at91_wdt_info = {
|
|
.identity = "at91 watchdog",
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
|
|
};
|
|
|
|
/*
|
|
* Handle commands from user-space.
|
|
*/
|
|
static long at91_wdt_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int new_value;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &at91_wdt_info,
|
|
sizeof(at91_wdt_info)) ? -EFAULT : 0;
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
case WDIOC_SETOPTIONS:
|
|
if (get_user(new_value, p))
|
|
return -EFAULT;
|
|
if (new_value & WDIOS_DISABLECARD)
|
|
at91_wdt_stop();
|
|
if (new_value & WDIOS_ENABLECARD)
|
|
at91_wdt_start();
|
|
return 0;
|
|
case WDIOC_KEEPALIVE:
|
|
at91_wdt_reload(); /* pat the watchdog */
|
|
return 0;
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_value, p))
|
|
return -EFAULT;
|
|
if (at91_wdt_settimeout(new_value))
|
|
return -EINVAL;
|
|
/* Enable new time value */
|
|
at91_wdt_start();
|
|
/* Return current value */
|
|
return put_user(wdt_time, p);
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(wdt_time, p);
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Pat the watchdog whenever device is written to.
|
|
*/
|
|
static ssize_t at91_wdt_write(struct file *file, const char *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
at91_wdt_reload(); /* pat the watchdog */
|
|
return len;
|
|
}
|
|
|
|
/* ......................................................................... */
|
|
|
|
static const struct file_operations at91wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.unlocked_ioctl = at91_wdt_ioctl,
|
|
.open = at91_wdt_open,
|
|
.release = at91_wdt_close,
|
|
.write = at91_wdt_write,
|
|
};
|
|
|
|
static struct miscdevice at91wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &at91wdt_fops,
|
|
};
|
|
|
|
static int __init at91wdt_probe(struct platform_device *pdev)
|
|
{
|
|
int res;
|
|
|
|
if (at91wdt_miscdev.parent)
|
|
return -EBUSY;
|
|
at91wdt_miscdev.parent = &pdev->dev;
|
|
|
|
res = misc_register(&at91wdt_miscdev);
|
|
if (res)
|
|
return res;
|
|
|
|
printk(KERN_INFO "AT91 Watchdog Timer enabled (%d seconds%s)\n",
|
|
wdt_time, nowayout ? ", nowayout" : "");
|
|
return 0;
|
|
}
|
|
|
|
static int __exit at91wdt_remove(struct platform_device *pdev)
|
|
{
|
|
int res;
|
|
|
|
res = misc_deregister(&at91wdt_miscdev);
|
|
if (!res)
|
|
at91wdt_miscdev.parent = NULL;
|
|
|
|
return res;
|
|
}
|
|
|
|
static void at91wdt_shutdown(struct platform_device *pdev)
|
|
{
|
|
at91_wdt_stop();
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
|
|
static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message)
|
|
{
|
|
at91_wdt_stop();
|
|
return 0;
|
|
}
|
|
|
|
static int at91wdt_resume(struct platform_device *pdev)
|
|
{
|
|
if (at91wdt_busy)
|
|
at91_wdt_start();
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
#define at91wdt_suspend NULL
|
|
#define at91wdt_resume NULL
|
|
#endif
|
|
|
|
static struct platform_driver at91wdt_driver = {
|
|
.probe = at91wdt_probe,
|
|
.remove = __exit_p(at91wdt_remove),
|
|
.shutdown = at91wdt_shutdown,
|
|
.suspend = at91wdt_suspend,
|
|
.resume = at91wdt_resume,
|
|
.driver = {
|
|
.name = "at91_wdt",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init at91_wdt_init(void)
|
|
{
|
|
/* Check that the heartbeat value is within range;
|
|
if not reset to the default */
|
|
if (at91_wdt_settimeout(wdt_time)) {
|
|
at91_wdt_settimeout(WDT_DEFAULT_TIME);
|
|
pr_info("at91_wdt: wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time);
|
|
}
|
|
|
|
return platform_driver_register(&at91wdt_driver);
|
|
}
|
|
|
|
static void __exit at91_wdt_exit(void)
|
|
{
|
|
platform_driver_unregister(&at91wdt_driver);
|
|
}
|
|
|
|
module_init(at91_wdt_init);
|
|
module_exit(at91_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Andrew Victor");
|
|
MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
MODULE_ALIAS("platform:at91_wdt");
|