linux/drivers/watchdog/it87_wdt.c
Guenter Roeck 893dc8b5c9 watchdog: it87: Drop support for resetting watchdog though CIR and Game port
Resetting the watchdog timer on CIR interrupts or on game port interrupts
is not not supported on recent chips, and doesn't really tell if the system
is stable. On top of that, at least the bit to enable resetting the
watchdog through the game port is used differently on recent chips.
Drop resetting the watchdog on CIR  or game port interrupts to simplify
the code.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-07-03 10:58:50 +02:00

375 lines
7.9 KiB
C

/*
* Watchdog Timer Driver
* for ITE IT87xx Environment Control - Low Pin Count Input / Output
*
* (c) Copyright 2007 Oliver Schuster <olivers137@aol.com>
*
* Based on softdog.c by Alan Cox,
* 83977f_wdt.c by Jose Goncalves,
* it87.c by Chris Gauthron, Jean Delvare
*
* Data-sheets: Publicly available at the ITE website
* http://www.ite.com.tw/
*
* Support of the watchdog timers, which are available on
* IT8620, IT8702, IT8712, IT8716, IT8718, IT8720, IT8721, IT8726,
* IT8728 and IT8783.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/io.h>
#define WATCHDOG_NAME "IT87 WDT"
/* Defaults for Module Parameter */
#define DEFAULT_TIMEOUT 60
#define DEFAULT_TESTMODE 0
#define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT
/* IO Ports */
#define REG 0x2e
#define VAL 0x2f
/* Logical device Numbers LDN */
#define GPIO 0x07
/* Configuration Registers and Functions */
#define LDNREG 0x07
#define CHIPID 0x20
#define CHIPREV 0x22
/* Chip Id numbers */
#define NO_DEV_ID 0xffff
#define IT8620_ID 0x8620
#define IT8702_ID 0x8702
#define IT8705_ID 0x8705
#define IT8712_ID 0x8712
#define IT8716_ID 0x8716
#define IT8718_ID 0x8718
#define IT8720_ID 0x8720
#define IT8721_ID 0x8721
#define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */
#define IT8728_ID 0x8728
#define IT8783_ID 0x8783
/* GPIO Configuration Registers LDN=0x07 */
#define WDTCTRL 0x71
#define WDTCFG 0x72
#define WDTVALLSB 0x73
#define WDTVALMSB 0x74
/* GPIO Bits WDTCFG */
#define WDT_TOV1 0x80
#define WDT_KRST 0x40
#define WDT_TOVE 0x20
#define WDT_PWROK 0x10 /* not in it8721 */
#define WDT_INT_MASK 0x0f
static unsigned int max_units, chip_type;
static unsigned int timeout = DEFAULT_TIMEOUT;
static int testmode = DEFAULT_TESTMODE;
static bool nowayout = DEFAULT_NOWAYOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
__MODULE_STRING(DEFAULT_TIMEOUT));
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
__MODULE_STRING(DEFAULT_TESTMODE));
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
__MODULE_STRING(WATCHDOG_NOWAYOUT));
/* Superio Chip */
static inline int superio_enter(void)
{
/*
* Try to reserve REG and REG + 1 for exclusive access.
*/
if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
return -EBUSY;
outb(0x87, REG);
outb(0x01, REG);
outb(0x55, REG);
outb(0x55, REG);
return 0;
}
static inline void superio_exit(void)
{
outb(0x02, REG);
outb(0x02, VAL);
release_region(REG, 2);
}
static inline void superio_select(int ldn)
{
outb(LDNREG, REG);
outb(ldn, VAL);
}
static inline int superio_inb(int reg)
{
outb(reg, REG);
return inb(VAL);
}
static inline void superio_outb(int val, int reg)
{
outb(reg, REG);
outb(val, VAL);
}
static inline 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_outw(int val, int reg)
{
outb(reg++, REG);
outb(val >> 8, VAL);
outb(reg, REG);
outb(val, VAL);
}
/* Internal function, should be called after superio_select(GPIO) */
static void _wdt_update_timeout(unsigned int t)
{
unsigned char cfg = WDT_KRST;
if (testmode)
cfg = 0;
if (t <= max_units)
cfg |= WDT_TOV1;
else
t /= 60;
if (chip_type != IT8721_ID)
cfg |= WDT_PWROK;
superio_outb(cfg, WDTCFG);
superio_outb(t, WDTVALLSB);
if (max_units > 255)
superio_outb(t >> 8, WDTVALMSB);
}
static int wdt_update_timeout(unsigned int t)
{
int ret;
ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
_wdt_update_timeout(t);
superio_exit();
return 0;
}
static int wdt_round_time(int t)
{
t += 59;
t -= t % 60;
return t;
}
/* watchdog timer handling */
static int wdt_start(struct watchdog_device *wdd)
{
return wdt_update_timeout(wdd->timeout);
}
static int wdt_stop(struct watchdog_device *wdd)
{
return wdt_update_timeout(0);
}
/**
* wdt_set_timeout - set a new timeout value with watchdog ioctl
* @t: timeout value in seconds
*
* The hardware device has a 8 or 16 bit watchdog timer (depends on
* chip version) that can be configured to count seconds or minutes.
*
* Used within WDIOC_SETTIMEOUT watchdog device ioctl.
*/
static int wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
int ret = 0;
if (t > max_units)
t = wdt_round_time(t);
wdd->timeout = t;
if (watchdog_hw_running(wdd))
ret = wdt_update_timeout(t);
return ret;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
static struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.set_timeout = wdt_set_timeout,
};
static struct watchdog_device wdt_dev = {
.info = &ident,
.ops = &wdt_ops,
.min_timeout = 1,
};
static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdt_stop(&wdt_dev);
return NOTIFY_DONE;
}
static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
static int __init it87_wdt_init(void)
{
u8 chip_rev;
int rc;
rc = superio_enter();
if (rc)
return rc;
chip_type = superio_inw(CHIPID);
chip_rev = superio_inb(CHIPREV) & 0x0f;
superio_exit();
switch (chip_type) {
case IT8702_ID:
max_units = 255;
break;
case IT8712_ID:
max_units = (chip_rev < 8) ? 255 : 65535;
break;
case IT8716_ID:
case IT8726_ID:
max_units = 65535;
break;
case IT8620_ID:
case IT8718_ID:
case IT8720_ID:
case IT8721_ID:
case IT8728_ID:
case IT8783_ID:
max_units = 65535;
break;
case IT8705_ID:
pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
chip_type, chip_rev);
return -ENODEV;
case NO_DEV_ID:
pr_err("no device\n");
return -ENODEV;
default:
pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
chip_type, chip_rev);
return -ENODEV;
}
rc = superio_enter();
if (rc)
return rc;
superio_select(GPIO);
superio_outb(WDT_TOV1, WDTCFG);
superio_outb(0x00, WDTCTRL);
superio_exit();
if (timeout < 1 || timeout > max_units * 60) {
timeout = DEFAULT_TIMEOUT;
pr_warn("Timeout value out of range, use default %d sec\n",
DEFAULT_TIMEOUT);
}
if (timeout > max_units)
timeout = wdt_round_time(timeout);
wdt_dev.timeout = timeout;
wdt_dev.max_timeout = max_units * 60;
rc = register_reboot_notifier(&wdt_notifier);
if (rc) {
pr_err("Cannot register reboot notifier (err=%d)\n", rc);
return rc;
}
rc = watchdog_register_device(&wdt_dev);
if (rc) {
pr_err("Cannot register watchdog device (err=%d)\n", rc);
goto err_out_reboot;
}
pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
chip_type, chip_rev, timeout, nowayout, testmode);
return 0;
err_out_reboot:
unregister_reboot_notifier(&wdt_notifier);
return rc;
}
static void __exit it87_wdt_exit(void)
{
watchdog_unregister_device(&wdt_dev);
unregister_reboot_notifier(&wdt_notifier);
}
module_init(it87_wdt_init);
module_exit(it87_wdt_exit);
MODULE_AUTHOR("Oliver Schuster");
MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
MODULE_LICENSE("GPL");