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linux/drivers/watchdog/w83697hf_wdt.c
Alexey Dobriyan c7dfd0cca3 [WATCHDOG] spin_lock_init() fixes 
Some watchdog drivers initialize global spinlocks in module's init function
which is tolerable, but some do it in PCI probe function.  So, switch to
static initialization to fix theoretical bugs and, more importantly, stop
giving people bad examples.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-11-02 19:09:07 +00:00

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9.3 KiB
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/*
* w83697hf/hg WDT driver
*
* (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
* (c) Copyright 2006 Marcus Junker <junker@anduras.de>
*
* Based on w83627hf_wdt.c which is based on advantechwdt.c
* which is based on wdt.c.
* Original copyright messages:
*
* (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
*
* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
*
* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
* http://www.redhat.com
*
* 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.
*
* Neither Marcus Junker nor ANDURAS AG admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define WATCHDOG_NAME "w83697hf/hg WDT"
#define PFX WATCHDOG_NAME ": "
#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
static unsigned long wdt_is_open;
static char expect_close;
static DEFINE_SPINLOCK(io_lock);
/* You must set this - there is no sane way to probe for this board. */
static int wdt_io = 0x2e;
module_param(wdt_io, int, 0);
MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
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) ")");
/*
* Kernel methods.
*/
#define W83697HF_EFER (wdt_io+0) /* Extended Function Enable Register */
#define W83697HF_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
#define W83697HF_EFDR (wdt_io+1) /* Extended Function Data Register */
static inline void
w83697hf_unlock(void)
{
outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
outb_p(0x87, W83697HF_EFER); /* Again according to manual */
}
static inline void
w83697hf_lock(void)
{
outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
}
/*
* The three functions w83697hf_get_reg(), w83697hf_set_reg() and
* w83697hf_write_timeout() must be called with the device unlocked.
*/
static unsigned char
w83697hf_get_reg(unsigned char reg)
{
outb_p(reg, W83697HF_EFIR);
return inb_p(W83697HF_EFDR);
}
static void
w83697hf_set_reg(unsigned char reg, unsigned char data)
{
outb_p(reg, W83697HF_EFIR);
outb_p(data, W83697HF_EFDR);
}
static void
w83697hf_write_timeout(int timeout)
{
w83697hf_set_reg(0xF4, timeout); /* Write Timeout counter to CRF4 */
}
static void
w83697hf_select_wdt(void)
{
w83697hf_unlock();
w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
}
static inline void
w83697hf_deselect_wdt(void)
{
w83697hf_lock();
}
static void
w83697hf_init(void)
{
unsigned char bbuf;
w83697hf_select_wdt();
bbuf = w83697hf_get_reg(0x29);
bbuf &= ~0x60;
bbuf |= 0x20;
w83697hf_set_reg(0x29, bbuf); /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
bbuf = w83697hf_get_reg(0xF3);
bbuf &= ~0x04;
w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
w83697hf_deselect_wdt();
}
static int
wdt_ping(void)
{
spin_lock(&io_lock);
w83697hf_select_wdt();
w83697hf_write_timeout(timeout);
w83697hf_deselect_wdt();
spin_unlock(&io_lock);
return 0;
}
static int
wdt_enable(void)
{
spin_lock(&io_lock);
w83697hf_select_wdt();
w83697hf_write_timeout(timeout);
w83697hf_set_reg(0x30, 1); /* Enable timer */
w83697hf_deselect_wdt();
spin_unlock(&io_lock);
return 0;
}
static int
wdt_disable(void)
{
spin_lock(&io_lock);
w83697hf_select_wdt();
w83697hf_set_reg(0x30, 0); /* Disable timer */
w83697hf_write_timeout(0);
w83697hf_deselect_wdt();
spin_unlock(&io_lock);
return 0;
}
static int
wdt_set_heartbeat(int t)
{
if ((t < 1) || (t > 255))
return -EINVAL;
timeout = t;
return 0;
}
static ssize_t
wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
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;
}
}
wdt_ping();
}
return count;
}
static int
wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_timeout;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "W83697HF WDT",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
wdt_ping();
break;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
if (wdt_set_heartbeat(new_timeout))
return -EINVAL;
wdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
wdt_disable();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
wdt_enable();
retval = 0;
}
return retval;
}
default:
return -ENOTTY;
}
return 0;
}
static int
wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &wdt_is_open))
return -EBUSY;
/*
* Activate
*/
wdt_enable();
return nonseekable_open(inode, file);
}
static int
wdt_close(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
wdt_disable();
} else {
printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
wdt_ping();
}
expect_close = 0;
clear_bit(0, &wdt_is_open);
return 0;
}
/*
* Notifier for system down
*/
static int
wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT) {
/* Turn the WDT off */
wdt_disable();
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdt_write,
.ioctl = wdt_ioctl,
.open = wdt_open,
.release = wdt_close,
};
static struct miscdevice wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt_fops,
};
/*
* The WDT needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
static int
w83697hf_check_wdt(void)
{
if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
printk (KERN_ERR PFX "I/O address 0x%x already in use\n", wdt_io);
return -EIO;
}
printk (KERN_DEBUG PFX "Looking for watchdog at address 0x%x\n", wdt_io);
w83697hf_unlock();
if (w83697hf_get_reg(0x20) == 0x60) {
printk (KERN_INFO PFX "watchdog found at address 0x%x\n", wdt_io);
w83697hf_lock();
return 0;
}
w83697hf_lock(); /* Reprotect in case it was a compatible device */
printk (KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io);
release_region(wdt_io, 2);
return -EIO;
}
static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
static int __init
wdt_init(void)
{
int ret, i, found = 0;
printk (KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n");
if (wdt_io == 0) {
/* we will autodetect the W83697HF/HG watchdog */
for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
wdt_io = w83697hf_ioports[i];
if (!w83697hf_check_wdt())
found++;
}
} else {
if (!w83697hf_check_wdt())
found++;
}
if (!found) {
printk (KERN_ERR PFX "No W83697HF/HG could be found\n");
ret = -EIO;
goto out;
}
w83697hf_init();
wdt_disable(); /* Disable watchdog until first use */
if (wdt_set_heartbeat(timeout)) {
wdt_set_heartbeat(WATCHDOG_TIMEOUT);
printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
WATCHDOG_TIMEOUT);
}
ret = register_reboot_notifier(&wdt_notifier);
if (ret != 0) {
printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
ret);
goto unreg_regions;
}
ret = misc_register(&wdt_miscdev);
if (ret != 0) {
printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto unreg_reboot;
}
printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
out:
return ret;
unreg_reboot:
unregister_reboot_notifier(&wdt_notifier);
unreg_regions:
release_region(wdt_io, 2);
goto out;
}
static void __exit
wdt_exit(void)
{
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
release_region(wdt_io, 2);
}
module_init(wdt_init);
module_exit(wdt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>");
MODULE_DESCRIPTION("w83697hf/hg WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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