- 根目录:
- drivers
- watchdog
- wdt977.c
/*
* Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip
*
* (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
*
* -----------------------
*
* 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.
*
* -----------------------
* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
* 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
* 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
* from minutes to seconds.
* 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
* nwwatchdog_init.
* 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
* remove limitiation to be used on
* Netwinders only
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#define WATCHDOG_VERSION "0.04"
#define WATCHDOG_NAME "Wdt977"
#define PFX WATCHDOG_NAME ": "
#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
#define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */
#define IO_DATA_PORT (IO_INDEX_PORT + 1)
#define UNLOCK_DATA 0x87
#define LOCK_DATA 0xAA
#define DEVICE_REGISTER 0x07
#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
static int timeout = DEFAULT_TIMEOUT;
static int timeoutM; /* timeout in minutes */
static unsigned long timer_alive;
static int testmode;
static char expect_close;
static DEFINE_SPINLOCK(spinlock);
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
__MODULE_STRING(DEFAULT_TIMEOUT) ")");
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Start the watchdog
*/
static int wdt977_start(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
* F2 has the timeout in minutes
* F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
* at timeout, and to reset timer on kbd/mouse activity (not impl.)
* F4 is used to just clear the TIMEOUT'ed state (bit 0)
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(timeoutM, IO_DATA_PORT);
outb_p(0xF3, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for
kbd/mouse/LED */
outb_p(0xF4, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
/* At last select device Aux1 (dev=7) and set GP16 as a
* watchdog output. In test mode watch the bit 1 on F4 to
* indicate "triggered"
*/
if (!testmode) {
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x07, IO_DATA_PORT);
outb_p(0xE6, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
}
/* lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
printk(KERN_INFO PFX "activated.\n");
return 0;
}
/*
* Stop the watchdog
*/
static int wdt977_stop(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
* F3 is reset to its default state
* F4 can clear the TIMEOUT'ed state (bit 0) - back to default
* We can not use GP17 as a PowerLed, as we use its usage as a RedLed
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(0xFF, IO_DATA_PORT);
outb_p(0xF3, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
outb_p(0xF4, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
/* at last select device Aux1 (dev=7) and set
GP16 as a watchdog output */
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x07, IO_DATA_PORT);
outb_p(0xE6, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
/* lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
printk(KERN_INFO PFX "shutdown.\n");
return 0;
}
/*
* Send a keepalive ping to the watchdog
* This is done by simply re-writing the timeout to reg. 0xF2
*/
static int wdt977_keepalive(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* select device Aux2 (device=8) and kicks watchdog reg F2 */
/* F2 has the timeout in minutes */
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(timeoutM, IO_DATA_PORT);
/* lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
return 0;
}
/*
* Set the watchdog timeout value
*/
static int wdt977_set_timeout(int t)
{
int tmrval;
/* convert seconds to minutes, rounding up */
tmrval = (t + 59) / 60;
if (machine_is_netwinder()) {
/* we have a hw bug somewhere, so each 977 minute is actually
* only 30sec. This limits the max timeout to half of device
* max of 255 minutes...
*/
tmrval += tmrval;
}
if (tmrval < 1 || tmrval > 255)
return -EINVAL;
/* timeout is the timeout in seconds, timeoutM is
the timeout in minutes) */
timeout = t;
timeoutM = tmrval;
return 0;
}
/*
* Get the watchdog status
*/
static int wdt977_get_status(int *status)
{
int new_status;
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* select device Aux2 (device=8) and read watchdog reg F4 */
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF4, IO_INDEX_PORT);
new_status = inb_p(IO_DATA_PORT);
/* lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
*status = 0;
if (new_status & 1)
*status |= WDIOF_CARDRESET;
return 0;
}
/*
* /dev/watchdog handling
*/
static int wdt977_open(struct inode *inode, struct file *file)
{
/* If the watchdog is alive we don't need to start it again */
if (test_and_set_bit(0, &timer_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
wdt977_start();
return nonseekable_open(inode, file);
}
static int wdt977_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
* Lock it in if it's a module and we set nowayout
*/
if (expect_close == 42) {
wdt977_stop();
clear_bit(0, &timer_alive);
} else {
wdt977_keepalive();
printk(KERN_CRIT PFX
"Unexpected close, not stopping watchdog!\n");
}
expect_close = 0;
return 0;
}
/*
* wdt977_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t wdt977_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
/* someone wrote to us, we should restart timer */
wdt977_keepalive();
}
return count;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
/*
* wdt977_ioctl:
* @inode: inode of the device
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features.
*/
static long wdt977_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int status;
int new_options, retval = -EINVAL;
int new_timeout;
union {
struct watchdog_info __user *ident;
int __user *i;
} uarg;
uarg.i = (int __user *)arg;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(uarg.ident, &ident,
sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
wdt977_get_status(&status);
return put_user(status, uarg.i);
case WDIOC_GETBOOTSTATUS:
return put_user(0, uarg.i);
case WDIOC_SETOPTIONS:
if (get_user(new_options, uarg.i))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD) {
wdt977_stop();
retval = 0;
}
if (new_options & WDIOS_ENABLECARD) {
wdt977_start();
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
wdt977_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, uarg.i))
return -EFAULT;
if (wdt977_set_timeout(new_timeout))
return -EINVAL;
wdt977_keepalive();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(timeout, uarg.i);
default:
return -ENOTTY;
}
}
static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdt977_stop();
return NOTIFY_DONE;
}
static const struct file_operations wdt977_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdt977_write,
.unlocked_ioctl = wdt977_ioctl,
.open = wdt977_open,
.release = wdt977_release,
};
static struct miscdevice wdt977_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt977_fops,
};
static struct notifier_block wdt977_notifier = {
.notifier_call = wdt977_notify_sys,
};
static int __init wd977_init(void)
{
int rc;
printk(KERN_INFO PFX DRIVER_VERSION);
/* Check that the timeout value is within its range;
if not reset to the default */
if (wdt977_set_timeout(timeout)) {
wdt977_set_timeout(DEFAULT_TIMEOUT);
printk(KERN_INFO PFX
"timeout value must be 60 < timeout < 15300, using %d\n",
DEFAULT_TIMEOUT);
}
/* on Netwinder the IOports are already reserved by
* arch/arm/mach-footbridge/netwinder-hw.c
*/
if (!machine_is_netwinder()) {
if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
printk(KERN_ERR PFX
"I/O address 0x%04x already in use\n",
IO_INDEX_PORT);
rc = -EIO;
goto err_out;
}
}
rc = register_reboot_notifier(&wdt977_notifier);
if (rc) {
printk(KERN_ERR PFX
"cannot register reboot notifier (err=%d)\n", rc);
goto err_out_region;
}
rc = misc_register(&wdt977_miscdev);
if (rc) {
printk(KERN_ERR PFX
"cannot register miscdev on minor=%d (err=%d)\n",
wdt977_miscdev.minor, rc);
goto err_out_reboot;
}
printk(KERN_INFO PFX
"initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
timeout, nowayout, testmode);
return 0;
err_out_reboot:
unregister_reboot_notifier(&wdt977_notifier);
err_out_region:
if (!machine_is_netwinder())
release_region(IO_INDEX_PORT, 2);
err_out:
return rc;
}
static void __exit wd977_exit(void)
{
wdt977_stop();
misc_deregister(&wdt977_miscdev);
unregister_reboot_notifier(&wdt977_notifier);
release_region(IO_INDEX_PORT, 2);
}
module_init(wd977_init);
module_exit(wd977_exit);
MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
MODULE_DESCRIPTION("W83977AF Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);