271 lines
6.0 KiB
C
271 lines
6.0 KiB
C
/*
|
|
* Driver for the Atheros AR71xx SoC's built-in hardware watchdog timer.
|
|
*
|
|
* Copyright (C) 2008 Gabor Juhos <juhosg@openwrt.org>
|
|
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
|
|
*
|
|
* This driver was based on: drivers/watchdog/ixp4xx_wdt.c
|
|
* Author: Deepak Saxena <dsaxena@plexity.net>
|
|
* Copyright 2004 (c) MontaVista, Software, Inc.
|
|
*
|
|
* which again was based on sa1100 driver,
|
|
* Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published
|
|
* by the Free Software Foundation.
|
|
*
|
|
*/
|
|
|
|
#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 <asm/mach-ar71xx/ar71xx.h>
|
|
|
|
#define DRV_NAME "ar71xx-wdt"
|
|
#define DRV_DESC "Atheros AR71xx hardware watchdog driver"
|
|
#define DRV_VERSION "0.1.0"
|
|
|
|
#define WDT_TIMEOUT 15 /* seconds */
|
|
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
#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 wdt_flags;
|
|
|
|
#define WDT_FLAGS_BUSY 0
|
|
#define WDT_FLAGS_EXPECT_CLOSE 1
|
|
|
|
static int wdt_timeout = WDT_TIMEOUT;
|
|
static int boot_status;
|
|
static int max_timeout;
|
|
|
|
static void inline ar71xx_wdt_keepalive(void)
|
|
{
|
|
ar71xx_reset_wr(AR71XX_RESET_REG_WDOG, ar71xx_ahb_freq * wdt_timeout);
|
|
}
|
|
|
|
static void inline ar71xx_wdt_enable(void)
|
|
{
|
|
printk(KERN_DEBUG DRV_NAME ": enabling watchdog timer\n");
|
|
ar71xx_wdt_keepalive();
|
|
ar71xx_reset_wr(AR71XX_RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_FCR);
|
|
}
|
|
|
|
static void inline ar71xx_wdt_disable(void)
|
|
{
|
|
printk(KERN_DEBUG DRV_NAME ": disabling watchdog timer\n");
|
|
ar71xx_reset_wr(AR71XX_RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_NONE);
|
|
}
|
|
|
|
static int ar71xx_wdt_set_timeout(int val)
|
|
{
|
|
if (val < 1 || val > max_timeout)
|
|
return -EINVAL;
|
|
|
|
wdt_timeout = val;
|
|
ar71xx_wdt_keepalive();
|
|
|
|
printk(KERN_DEBUG DRV_NAME ": timeout=%d secs\n", wdt_timeout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ar71xx_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(WDT_FLAGS_BUSY, &wdt_flags))
|
|
return -EBUSY;
|
|
|
|
clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
|
|
|
|
ar71xx_wdt_enable();
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int ar71xx_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags)) {
|
|
ar71xx_wdt_disable();
|
|
} else {
|
|
printk(KERN_CRIT DRV_NAME ": device closed unexpectedly, "
|
|
"watchdog timer will not stop!\n");
|
|
}
|
|
|
|
clear_bit(WDT_FLAGS_BUSY, &wdt_flags);
|
|
clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t ar71xx_wdt_write(struct file *file, const char *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
if (len) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
|
|
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
|
|
if (c == 'V')
|
|
set_bit(WDT_FLAGS_EXPECT_CLOSE,
|
|
&wdt_flags);
|
|
}
|
|
}
|
|
|
|
ar71xx_wdt_keepalive();
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
static struct watchdog_info ar71xx_wdt_info = {
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
|
|
WDIOF_MAGICCLOSE | WDIOF_CARDRESET,
|
|
.firmware_version = 0,
|
|
.identity = "AR71XX watchdog",
|
|
};
|
|
|
|
static long ar71xx_wdt_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
int t;
|
|
int ret;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
ret = copy_to_user((struct watchdog_info *)arg,
|
|
&ar71xx_wdt_info,
|
|
sizeof(&ar71xx_wdt_info)) ? -EFAULT : 0;
|
|
break;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
ret = put_user(0, (int *)arg) ? -EFAULT : 0;
|
|
break;
|
|
|
|
case WDIOC_GETBOOTSTATUS:
|
|
ret = put_user(boot_status, (int *)arg) ? -EFAULT : 0;
|
|
break;
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
ar71xx_wdt_keepalive();
|
|
ret = 0;
|
|
break;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
ret = get_user(t, (int *)arg) ? -EFAULT : 0;
|
|
if (ret)
|
|
break;
|
|
|
|
ret = ar71xx_wdt_set_timeout(t);
|
|
if (ret)
|
|
break;
|
|
|
|
/* fallthrough */
|
|
case WDIOC_GETTIMEOUT:
|
|
ret = put_user(wdt_timeout, (int *)arg) ? -EFAULT : 0;
|
|
break;
|
|
|
|
default:
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations ar71xx_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.write = ar71xx_wdt_write,
|
|
.unlocked_ioctl = ar71xx_wdt_ioctl,
|
|
.open = ar71xx_wdt_open,
|
|
.release = ar71xx_wdt_release,
|
|
};
|
|
|
|
static struct miscdevice ar71xx_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &ar71xx_wdt_fops,
|
|
};
|
|
|
|
static int __devinit ar71xx_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
int ret;
|
|
|
|
max_timeout = (0xfffffffful / ar71xx_ahb_freq);
|
|
wdt_timeout = (max_timeout < WDT_TIMEOUT) ? max_timeout : WDT_TIMEOUT;
|
|
|
|
boot_status =
|
|
(ar71xx_reset_rr(AR71XX_RESET_REG_WDOG_CTRL) & WDOG_CTRL_LAST_RESET) ?
|
|
WDIOF_CARDRESET : 0;
|
|
|
|
ret = misc_register(&ar71xx_wdt_miscdev);
|
|
if (ret)
|
|
goto err_out;
|
|
|
|
printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
|
|
|
|
printk(KERN_DEBUG DRV_NAME ": timeout=%d secs (max=%d)\n",
|
|
wdt_timeout, max_timeout);
|
|
|
|
return 0;
|
|
|
|
err_out:
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit ar71xx_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
misc_deregister(&ar71xx_wdt_miscdev);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ar71xx_wdt_driver = {
|
|
.probe = ar71xx_wdt_probe,
|
|
.remove = __devexit_p(ar71xx_wdt_remove),
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init ar71xx_wdt_init(void)
|
|
{
|
|
return platform_driver_register(&ar71xx_wdt_driver);
|
|
}
|
|
module_init(ar71xx_wdt_init);
|
|
|
|
static void __exit ar71xx_wdt_exit(void)
|
|
{
|
|
platform_driver_unregister(&ar71xx_wdt_driver);
|
|
}
|
|
module_exit(ar71xx_wdt_exit);
|
|
|
|
MODULE_DESCRIPTION(DRV_DESC);
|
|
MODULE_VERSION(DRV_VERSION);
|
|
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
|
|
MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:" DRV_NAME);
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|