linux-hardened/drivers/watchdog/it8712f_wdt.c
Andrew Paprocki cc1020f15a [WATCHDOG] it8712f_wdt Zero MSB timeout byte when disabling watchdog
I noticed this while testing the latest code. I'm not sure if it is required,
but the normal (or LSB) timeout value is set to zero, so the MSB should
be as well to stay consistent.

If the chip revision is >= 8, set MSB of the 16-bit timeout value to zero
when disabling the watchdog in it8712f_wdt_disable().

Signed-off-by: Andrew Paprocki <andrew@ishiboo.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-04-06 19:12:22 +00:00

442 lines
9.1 KiB
C

/*
* IT8712F "Smart Guardian" Watchdog support
*
* Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
*
* Based on info and code taken from:
*
* drivers/char/watchdog/scx200_wdt.c
* drivers/hwmon/it87.c
* IT8712F EC-LPC I/O Preliminary Specification 0.8.2
* IT8712F EC-LPC I/O Preliminary Specification 0.9.3
*
* 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.
*
* The author(s) of this software shall not be held liable for damages
* of any nature resulting due to the use of this software. This
* software is provided AS-IS with no warranties.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#define NAME "it8712f_wdt"
MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
MODULE_DESCRIPTION("IT8712F Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
static int max_units = 255;
static int margin = 60; /* in seconds */
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
static struct semaphore it8712f_wdt_sem;
static unsigned expect_close;
static spinlock_t io_lock;
static unsigned char revision;
/* Dog Food address - We use the game port address */
static unsigned short address;
#define REG 0x2e /* The register to read/write */
#define VAL 0x2f /* The value to read/write */
#define LDN 0x07 /* Register: Logical device select */
#define DEVID 0x20 /* Register: Device ID */
#define DEVREV 0x22 /* Register: Device Revision */
#define ACT_REG 0x30 /* LDN Register: Activation */
#define BASE_REG 0x60 /* LDN Register: Base address */
#define IT8712F_DEVID 0x8712
#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
#define LDN_GAME 0x09 /* Game Port */
#define WDT_CONTROL 0x71 /* WDT Register: Control */
#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
#define WDT_RESET_GAME 0x10
#define WDT_RESET_KBD 0x20
#define WDT_RESET_MOUSE 0x40
#define WDT_RESET_CIR 0x80
#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
#define WDT_OUT_PWROK 0x10
#define WDT_OUT_KRST 0x40
static int
superio_inb(int reg)
{
outb(reg, REG);
return inb(VAL);
}
static void
superio_outb(int val, int reg)
{
outb(reg, REG);
outb(val, VAL);
}
static int
superio_inw(int reg)
{
int val;
outb(reg++, REG);
val = inb(VAL) << 8;
outb(reg, REG);
val |= inb(VAL);
return val;
}
static inline void
superio_select(int ldn)
{
outb(LDN, REG);
outb(ldn, VAL);
}
static inline void
superio_enter(void)
{
spin_lock(&io_lock);
outb(0x87, REG);
outb(0x01, REG);
outb(0x55, REG);
outb(0x55, REG);
}
static inline void
superio_exit(void)
{
outb(0x02, REG);
outb(0x02, VAL);
spin_unlock(&io_lock);
}
static inline void
it8712f_wdt_ping(void)
{
inb(address);
}
static void
it8712f_wdt_update_margin(void)
{
int config = WDT_OUT_KRST | WDT_OUT_PWROK;
int units = margin;
/* Switch to minutes precision if the configured margin
* value does not fit within the register width.
*/
if (units <= max_units) {
config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */
printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
} else {
units /= 60;
printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
}
superio_outb(config, WDT_CONFIG);
if (revision >= 0x08)
superio_outb(units >> 8, WDT_TIMEOUT + 1);
superio_outb(units, WDT_TIMEOUT);
}
static int
it8712f_wdt_get_status(void)
{
if (superio_inb(WDT_CONTROL) & 0x01)
return WDIOF_CARDRESET;
else
return 0;
}
static void
it8712f_wdt_enable(void)
{
printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
superio_enter();
superio_select(LDN_GPIO);
superio_outb(WDT_RESET_GAME, WDT_CONTROL);
it8712f_wdt_update_margin();
superio_exit();
it8712f_wdt_ping();
}
static void
it8712f_wdt_disable(void)
{
printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
superio_enter();
superio_select(LDN_GPIO);
superio_outb(0, WDT_CONFIG);
superio_outb(0, WDT_CONTROL);
if (revision >= 0x08)
superio_outb(0, WDT_TIMEOUT + 1);
superio_outb(0, WDT_TIMEOUT);
superio_exit();
}
static int
it8712f_wdt_notify(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_HALT || code == SYS_POWER_OFF)
if (!nowayout)
it8712f_wdt_disable();
return NOTIFY_DONE;
}
static struct notifier_block it8712f_wdt_notifier = {
.notifier_call = it8712f_wdt_notify,
};
static ssize_t
it8712f_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* check for a magic close character */
if (len) {
size_t i;
it8712f_wdt_ping();
expect_close = 0;
for (i = 0; i < len; ++i) {
char c;
if (get_user(c, data+i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
return len;
}
static int
it8712f_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
static struct watchdog_info ident = {
.identity = "IT8712F Watchdog",
.firmware_version = 1,
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
};
int value;
switch (cmd) {
default:
return -ENOTTY;
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
superio_enter();
superio_select(LDN_GPIO);
value = it8712f_wdt_get_status();
superio_exit();
return put_user(value, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
it8712f_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(value, p))
return -EFAULT;
if (value < 1)
return -EINVAL;
if (value > (max_units * 60))
return -EINVAL;
margin = value;
superio_enter();
superio_select(LDN_GPIO);
it8712f_wdt_update_margin();
superio_exit();
it8712f_wdt_ping();
/* Fall through */
case WDIOC_GETTIMEOUT:
if (put_user(margin, p))
return -EFAULT;
return 0;
}
}
static int
it8712f_wdt_open(struct inode *inode, struct file *file)
{
/* only allow one at a time */
if (down_trylock(&it8712f_wdt_sem))
return -EBUSY;
it8712f_wdt_enable();
return nonseekable_open(inode, file);
}
static int
it8712f_wdt_release(struct inode *inode, struct file *file)
{
if (expect_close != 42) {
printk(KERN_WARNING NAME
": watchdog device closed unexpectedly, will not"
" disable the watchdog timer\n");
} else if (!nowayout) {
it8712f_wdt_disable();
}
expect_close = 0;
up(&it8712f_wdt_sem);
return 0;
}
static const struct file_operations it8712f_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = it8712f_wdt_write,
.ioctl = it8712f_wdt_ioctl,
.open = it8712f_wdt_open,
.release = it8712f_wdt_release,
};
static struct miscdevice it8712f_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &it8712f_wdt_fops,
};
static int __init
it8712f_wdt_find(unsigned short *address)
{
int err = -ENODEV;
int chip_type;
superio_enter();
chip_type = superio_inw(DEVID);
if (chip_type != IT8712F_DEVID)
goto exit;
superio_select(LDN_GAME);
superio_outb(1, ACT_REG);
if (!(superio_inb(ACT_REG) & 0x01)) {
printk(KERN_ERR NAME ": Device not activated, skipping\n");
goto exit;
}
*address = superio_inw(BASE_REG);
if (*address == 0) {
printk(KERN_ERR NAME ": Base address not set, skipping\n");
goto exit;
}
err = 0;
revision = superio_inb(DEVREV) & 0x0f;
/* Later revisions have 16-bit values per datasheet 0.9.1 */
if (revision >= 0x08)
max_units = 65535;
if (margin > (max_units * 60))
margin = (max_units * 60);
printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
"using DogFood address 0x%x\n",
chip_type, revision, *address);
exit:
superio_exit();
return err;
}
static int __init
it8712f_wdt_init(void)
{
int err = 0;
spin_lock_init(&io_lock);
if (it8712f_wdt_find(&address))
return -ENODEV;
if (!request_region(address, 1, "IT8712F Watchdog")) {
printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
return -EBUSY;
}
it8712f_wdt_disable();
sema_init(&it8712f_wdt_sem, 1);
err = register_reboot_notifier(&it8712f_wdt_notifier);
if (err) {
printk(KERN_ERR NAME ": unable to register reboot notifier\n");
goto out;
}
err = misc_register(&it8712f_wdt_miscdev);
if (err) {
printk(KERN_ERR NAME
": cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, err);
goto reboot_out;
}
return 0;
reboot_out:
unregister_reboot_notifier(&it8712f_wdt_notifier);
out:
release_region(address, 1);
return err;
}
static void __exit
it8712f_wdt_exit(void)
{
misc_deregister(&it8712f_wdt_miscdev);
unregister_reboot_notifier(&it8712f_wdt_notifier);
release_region(address, 1);
}
module_init(it8712f_wdt_init);
module_exit(it8712f_wdt_exit);