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linux/drivers/watchdog/w83627hf_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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/*
* w83627hf/thf WDT driver
*
* (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
* added support for W83627THF.
*
* (c) Copyright 2003,2007 Pádraig Brady <P@draigBrady.com>
*
* Based on advantechwdt.c which is based on wdt.c.
* Original copyright messages:
*
* (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 Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@redhat.com>
*/
#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 "w83627hf/thf/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, "w83627hf/thf WDT io port (default 0x2E)");
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 WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
#define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
static void
w83627hf_select_wd_register(void)
{
unsigned char c;
outb_p(0x87, WDT_EFER); /* Enter extended function mode */
outb_p(0x87, WDT_EFER); /* Again according to manual */
outb(0x20, WDT_EFER); /* check chip version */
c = inb(WDT_EFDR);
if (c == 0x82) { /* W83627THF */
outb_p(0x2b, WDT_EFER); /* select GPIO3 */
c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
outb_p(0x2b, WDT_EFER);
outb_p(c, WDT_EFDR); /* set GPIO3 to WDT0 */
}
outb_p(0x07, WDT_EFER); /* point to logical device number reg */
outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
outb_p(0x30, WDT_EFER); /* select CR30 */
outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
}
static void
w83627hf_unselect_wd_register(void)
{
outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
}
/* tyan motherboards seem to set F5 to 0x4C ?
* So explicitly init to appropriate value. */
static void
w83627hf_init(void)
{
unsigned char t;
w83627hf_select_wd_register();
outb_p(0xF6, WDT_EFER); /* Select CRF6 */
t=inb_p(WDT_EFDR); /* read CRF6 */
if (t != 0) {
printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
}
outb_p(0xF5, WDT_EFER); /* Select CRF5 */
t=inb_p(WDT_EFDR); /* read CRF5 */
t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
outb_p(t, WDT_EFDR); /* Write back to CRF5 */
outb_p(0xF7, WDT_EFER); /* Select CRF7 */
t=inb_p(WDT_EFDR); /* read CRF7 */
t&=~0xC0; /* disable keyboard & mouse turning off watchdog */
outb_p(t, WDT_EFDR); /* Write back to CRF7 */
w83627hf_unselect_wd_register();
}
static void
wdt_ctrl(int timeout)
{
spin_lock(&io_lock);
w83627hf_select_wd_register();
outb_p(0xF6, WDT_EFER); /* Select CRF6 */
outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
w83627hf_unselect_wd_register();
spin_unlock(&io_lock);
}
static int
wdt_ping(void)
{
wdt_ctrl(timeout);
return 0;
}
static int
wdt_disable(void)
{
wdt_ctrl(0);
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 = "W83627HF 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_ping();
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_ping();
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 __init
wdt_init(void)
{
int ret;
printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
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);
}
if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
wdt_io);
ret = -EIO;
goto out;
}
w83627hf_init();
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, 1);
goto out;
}
static void __exit
wdt_exit(void)
{
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
release_region(wdt_io,1);
}
module_init(wdt_init);
module_exit(wdt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
MODULE_DESCRIPTION("w83627hf/thf WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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