linux/drivers/char/watchdog/wdt977.c

455 lines
10 KiB
C

/*
* Wdt977 0.03: 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.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#include <asm/uaccess.h>
#define PFX "Wdt977: "
#define WATCHDOG_MINOR 130
#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;
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=CONFIG_WATCHDOG_NOWAYOUT)");
/*
* Start the watchdog
*/
static int wdt977_start(void)
{
/* unlock the SuperIO chip */
outb(0x87,0x370);
outb(0x87,0x370);
/* 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(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(timeoutM,0x371);
outb(0xF3,0x370);
outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */
outb(0xF4,0x370);
outb(0x00,0x371);
/* 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(0x07,0x370);
outb(0x07,0x371);
outb(0xE6,0x370);
outb(0x08,0x371);
}
/* lock the SuperIO chip */
outb(0xAA,0x370);
printk(KERN_INFO PFX "activated.\n");
return 0;
}
/*
* Stop the watchdog
*/
static int wdt977_stop(void)
{
/* unlock the SuperIO chip */
outb(0x87,0x370);
outb(0x87,0x370);
/* 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(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(0xFF,0x371);
outb(0xF3,0x370);
outb(0x00,0x371);
outb(0xF4,0x370);
outb(0x00,0x371);
outb(0xF2,0x370);
outb(0x00,0x371);
/* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
outb(0x07,0x370);
outb(0x07,0x371);
outb(0xE6,0x370);
outb(0x08,0x371);
/* lock the SuperIO chip */
outb(0xAA,0x370);
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)
{
/* unlock the SuperIO chip */
outb(0x87,0x370);
outb(0x87,0x370);
/* select device Aux2 (device=8) and kicks watchdog reg F2 */
/* F2 has the timeout in minutes */
outb(0x07,0x370);
outb(0x08,0x371);
outb(0xF2,0x370);
outb(timeoutM,0x371);
/* lock the SuperIO chip */
outb(0xAA,0x370);
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;
*status=0;
/* unlock the SuperIO chip */
outb(0x87,0x370);
outb(0x87,0x370);
/* select device Aux2 (device=8) and read watchdog reg F4 */
outb(0x07,0x370);
outb(0x08,0x371);
outb(0xF4,0x370);
new_status = inb(0x371);
/* lock the SuperIO chip */
outb(0xAA,0x370);
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 {
printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
wdt977_keepalive();
}
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;
}
}
wdt977_keepalive();
}
return count;
}
/*
* 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 struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = "Winbond 83977",
};
static int wdt977_ioctl(struct inode *inode, 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)
{
default:
return -ENOIOCTLCMD;
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_KEEPALIVE:
wdt977_keepalive();
return 0;
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_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);
}
}
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 struct file_operations wdt977_fops=
{
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdt977_write,
.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 nwwatchdog_init(void)
{
int retval;
if (!machine_is_netwinder())
return -ENODEV;
/* Check that the timeout value is within it's 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);
}
retval = register_reboot_notifier(&wdt977_notifier);
if (retval) {
printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
retval);
return retval;
}
retval = misc_register(&wdt977_miscdev);
if (retval) {
printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, retval);
unregister_reboot_notifier(&wdt977_notifier);
return retval;
}
printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode = %i)\n",
timeout, nowayout, testmode);
return 0;
}
static void __exit nwwatchdog_exit(void)
{
misc_deregister(&wdt977_miscdev);
unregister_reboot_notifier(&wdt977_notifier);
}
module_init(nwwatchdog_init);
module_exit(nwwatchdog_exit);
MODULE_AUTHOR("Woody Suwalski <woody@netwinder.org>");
MODULE_DESCRIPTION("W83977AF Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);