297 lines
6.5 KiB
C
297 lines
6.5 KiB
C
/*
|
|
* Watchdog driver for Freescale STMP37XX/STMP378X
|
|
*
|
|
* Author: Vitaly Wool <vital@embeddedalley.com>
|
|
*
|
|
* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
|
|
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <mach/platform.h>
|
|
#include <mach/regs-rtc.h>
|
|
|
|
#define DEFAULT_HEARTBEAT 19
|
|
#define MAX_HEARTBEAT (0x10000000 >> 6)
|
|
|
|
/* missing bitmask in headers */
|
|
#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
|
|
|
|
#define WDT_IN_USE 0
|
|
#define WDT_OK_TO_CLOSE 1
|
|
|
|
#define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */
|
|
|
|
static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
|
|
static unsigned long wdt_status;
|
|
static const int nowayout = WATCHDOG_NOWAYOUT;
|
|
static int heartbeat = DEFAULT_HEARTBEAT;
|
|
static unsigned long boot_status;
|
|
|
|
static void wdt_enable(u32 value)
|
|
{
|
|
spin_lock(&stmp3xxx_wdt_io_lock);
|
|
__raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
|
|
stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
|
|
stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
|
|
REGS_RTC_BASE + HW_RTC_PERSISTENT1);
|
|
spin_unlock(&stmp3xxx_wdt_io_lock);
|
|
}
|
|
|
|
static void wdt_disable(void)
|
|
{
|
|
spin_lock(&stmp3xxx_wdt_io_lock);
|
|
stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
|
|
REGS_RTC_BASE + HW_RTC_PERSISTENT1);
|
|
stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
|
|
spin_unlock(&stmp3xxx_wdt_io_lock);
|
|
}
|
|
|
|
static void wdt_ping(void)
|
|
{
|
|
wdt_enable(heartbeat * WDOG_COUNTER_RATE);
|
|
}
|
|
|
|
static int stmp3xxx_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
|
|
return -EBUSY;
|
|
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
wdt_ping();
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
if (len) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
}
|
|
}
|
|
wdt_ping();
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
static struct watchdog_info ident = {
|
|
.options = WDIOF_CARDRESET |
|
|
WDIOF_MAGICCLOSE |
|
|
WDIOF_SETTIMEOUT |
|
|
WDIOF_KEEPALIVEPING,
|
|
.identity = "STMP3XXX Watchdog",
|
|
};
|
|
|
|
static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int new_heartbeat, opts;
|
|
int ret = -ENOTTY;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
|
|
break;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
ret = put_user(0, p);
|
|
break;
|
|
|
|
case WDIOC_GETBOOTSTATUS:
|
|
ret = put_user(boot_status, p);
|
|
break;
|
|
|
|
case WDIOC_SETOPTIONS:
|
|
if (get_user(opts, p)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
if (opts & WDIOS_DISABLECARD)
|
|
wdt_disable();
|
|
else if (opts & WDIOS_ENABLECARD)
|
|
wdt_ping();
|
|
else {
|
|
pr_debug("%s: unknown option 0x%x\n", __func__, opts);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
ret = 0;
|
|
break;
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
wdt_ping();
|
|
ret = 0;
|
|
break;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_heartbeat, p)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
heartbeat = new_heartbeat;
|
|
wdt_ping();
|
|
/* Fall through */
|
|
|
|
case WDIOC_GETTIMEOUT:
|
|
ret = put_user(heartbeat, p);
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int stmp3xxx_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!nowayout) {
|
|
if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
|
|
wdt_ping();
|
|
pr_debug("%s: Device closed unexpectdly\n", __func__);
|
|
ret = -EINVAL;
|
|
} else {
|
|
wdt_disable();
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
}
|
|
}
|
|
clear_bit(WDT_IN_USE, &wdt_status);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations stmp3xxx_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = stmp3xxx_wdt_write,
|
|
.unlocked_ioctl = stmp3xxx_wdt_ioctl,
|
|
.open = stmp3xxx_wdt_open,
|
|
.release = stmp3xxx_wdt_release,
|
|
};
|
|
|
|
static struct miscdevice stmp3xxx_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &stmp3xxx_wdt_fops,
|
|
};
|
|
|
|
static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
|
|
heartbeat = DEFAULT_HEARTBEAT;
|
|
|
|
boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
|
|
BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
|
|
boot_status = !!boot_status;
|
|
stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
|
|
REGS_RTC_BASE + HW_RTC_PERSISTENT1);
|
|
wdt_disable(); /* disable for now */
|
|
|
|
ret = misc_register(&stmp3xxx_wdt_miscdev);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "cannot register misc device\n");
|
|
return ret;
|
|
}
|
|
|
|
printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n",
|
|
heartbeat);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
misc_deregister(&stmp3xxx_wdt_miscdev);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int wdt_suspended;
|
|
static u32 wdt_saved_time;
|
|
|
|
static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
|
|
pm_message_t state)
|
|
{
|
|
if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
|
|
BM_RTC_CTRL_WATCHDOGEN) {
|
|
wdt_suspended = 1;
|
|
wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
|
|
wdt_disable();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int stmp3xxx_wdt_resume(struct platform_device *pdev)
|
|
{
|
|
if (wdt_suspended) {
|
|
wdt_enable(wdt_saved_time);
|
|
wdt_suspended = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
#else
|
|
#define stmp3xxx_wdt_suspend NULL
|
|
#define stmp3xxx_wdt_resume NULL
|
|
#endif
|
|
|
|
static struct platform_driver platform_wdt_driver = {
|
|
.driver = {
|
|
.name = "stmp3xxx_wdt",
|
|
},
|
|
.probe = stmp3xxx_wdt_probe,
|
|
.remove = __devexit_p(stmp3xxx_wdt_remove),
|
|
.suspend = stmp3xxx_wdt_suspend,
|
|
.resume = stmp3xxx_wdt_resume,
|
|
};
|
|
|
|
static int __init stmp3xxx_wdt_init(void)
|
|
{
|
|
return platform_driver_register(&platform_wdt_driver);
|
|
}
|
|
|
|
static void __exit stmp3xxx_wdt_exit(void)
|
|
{
|
|
return platform_driver_unregister(&platform_wdt_driver);
|
|
}
|
|
|
|
module_init(stmp3xxx_wdt_init);
|
|
module_exit(stmp3xxx_wdt_exit);
|
|
|
|
MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_param(heartbeat, int, 0);
|
|
MODULE_PARM_DESC(heartbeat,
|
|
"Watchdog heartbeat period in seconds from 1 to "
|
|
__MODULE_STRING(MAX_HEARTBEAT) ", default "
|
|
__MODULE_STRING(DEFAULT_HEARTBEAT));
|
|
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|