/*
* w83627hf/thf WDT driver
*
* (c) Copyright 2013 Guenter Roeck
* converted to watchdog infrastructure
*
* (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@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* 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@lxorguk.ukuu.org.uk>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/io.h>
#define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
/* 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; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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 */
#define W83627HF_LD_WDT 0x08
static void superio_outb(int reg, int val)
{
outb(reg, WDT_EFER);
outb(val, WDT_EFDR);
}
static inline int superio_inb(int reg)
{
outb(reg, WDT_EFER);
return inb(WDT_EFDR);
}
static int superio_enter(void)
{
if (!request_muxed_region(wdt_io, 2, WATCHDOG_NAME))
return -EBUSY;
outb_p(0x87, WDT_EFER); /* Enter extended function mode */
outb_p(0x87, WDT_EFER); /* Again according to manual */
return 0;
}
static void superio_select(int ld)
{
superio_outb(0x07, ld);
}
static void superio_exit(void)
{
outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
release_region(wdt_io, 2);
}
/* tyan motherboards seem to set F5 to 0x4C ?
* So explicitly init to appropriate value. */
static int w83627hf_init(struct watchdog_device *wdog)
{
int ret;
unsigned char t;
ret = superio_enter();
if (ret)
return ret;
superio_select(W83627HF_LD_WDT);
t = superio_inb(0x20); /* check chip version */
if (t == 0x82) { /* W83627THF */
t = (superio_inb(0x2b) & 0xf7);
superio_outb(0x2b, t | 0x04); /* set GPIO3 to WDT0 */
} else if (t == 0x88 || t == 0xa0) { /* W83627EHF / W83627DHG */
t = superio_inb(0x2d);
superio_outb(0x2d, t & ~0x01); /* set GPIO5 to WDT0 */
}
/* set CR30 bit 0 to activate GPIO2 */
t = superio_inb(0x30);
if (!(t & 0x01))
superio_outb(0x30, t | 0x01);
t = superio_inb(0xF6);
if (t != 0) {
pr_info("Watchdog already running. Resetting timeout to %d sec\n",
wdog->timeout);
superio_outb(0xF6, wdog->timeout);
}
/* set second mode & disable keyboard turning off watchdog */
t = superio_inb(0xF5) & ~0x0C;
/* enable the WDTO# output low pulse to the KBRST# pin */
t |= 0x02;
superio_outb(0xF5, t);
/* disable keyboard & mouse turning off watchdog */
t = superio_inb(0xF7) & ~0xC0;
superio_outb(0xF7, t);
superio_exit();
return 0;
}
static int wdt_set_time(unsigned int timeout)
{
int ret;
ret = superio_enter();
if (ret)
return ret;
superio_select(W83627HF_LD_WDT);
superio_outb(0xF6, timeout);
superio_exit();
return 0;
}
static int wdt_start(struct watchdog_device *wdog)
{
return wdt_set_time(wdog->timeout);
}
static int wdt_stop(struct watchdog_device *wdog)
{
return wdt_set_time(0);
}
static int wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout)
{
wdog->timeout = timeout;
return 0;
}
static unsigned int wdt_get_time(struct watchdog_device *wdog)
{
unsigned int timeleft;
int ret;
ret = superio_enter();
if (ret)
return 0;
superio_select(W83627HF_LD_WDT);
timeleft = superio_inb(0xF6);
superio_exit();
return timeleft;
}
/*
* 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)
wdt_set_time(0); /* Turn the WDT off */
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static struct watchdog_info wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "W83627HF Watchdog",
};
static struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.set_timeout = wdt_set_timeout,
.get_timeleft = wdt_get_time,
};
static struct watchdog_device wdt_dev = {
.info = &wdt_info,
.ops = &wdt_ops,
.timeout = WATCHDOG_TIMEOUT,
.min_timeout = 1,
.max_timeout = 255,
};
/*
* 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;
pr_info("WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising\n");
watchdog_init_timeout(&wdt_dev, timeout, NULL);
watchdog_set_nowayout(&wdt_dev, nowayout);
ret = w83627hf_init(&wdt_dev);
if (ret) {
pr_err("failed to initialize watchdog (err=%d)\n", ret);
return ret;
}
ret = register_reboot_notifier(&wdt_notifier);
if (ret != 0) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
return ret;
}
ret = watchdog_register_device(&wdt_dev);
if (ret)
goto unreg_reboot;
pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
wdt_dev.timeout, nowayout);
return ret;
unreg_reboot:
unregister_reboot_notifier(&wdt_notifier);
return ret;
}
static void __exit wdt_exit(void)
{
watchdog_unregister_device(&wdt_dev);
unregister_reboot_notifier(&wdt_notifier);
}
module_init(wdt_init);
module_exit(wdt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
MODULE_DESCRIPTION("w83627hf/thf WDT driver");
