/*
* 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 */
static void w83627hf_select_wd_register(void)
{
outb_p(0x87, WDT_EFER); /* Enter extended function mode */
outb_p(0x87, WDT_EFER); /* Again according to manual */
outb_p(0x07, WDT_EFER); /* point to logical device number reg */
outb_p(0x08, WDT_EFDR); /* select logical device 8 (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(struct watchdog_device *wdog)
{
unsigned char t;
w83627hf_select_wd_register();
outb(0x20, WDT_EFER); /* check chip version */
t = inb(WDT_EFDR);
if (t == 0x82) { /* W83627THF */
outb_p(0x2b, WDT_EFER); /* select GPIO3 */
t = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
outb_p(0x2b, WDT_EFER);
outb_p(t, WDT_EFDR); /* set GPIO3 to WDT0 */
} else if (t == 0x88 || t == 0xa0) { /* W83627EHF / W83627DHG */
outb_p(0x2d, WDT_EFER); /* select GPIO5 */
t = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */
outb_p(0x2d, WDT_EFER);
outb_p(t, WDT_EFDR); /* set GPIO5 to WDT0 */
}
outb_p(0x30, WDT_EFER); /* select CR30 */
t = inb(WDT_EFDR);
if (!(t & 0x01))
outb_p(t | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
outb_p(0xF6, WDT_EFER); /* Select CRF6 */
t = inb_p(WDT_EFDR); /* read CRF6 */
if (t != 0) {
pr_info("Watchdog already running. Resetting timeout to %d sec\n",
wdog->timeout);
outb_p(wdog->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 */
t |= 0x02; /* enable the WDTO# output low pulse
to the KBRST# pin (PIN60) */
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 int wdt_set_time(unsigned int timeout)
{
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();
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;
w83627hf_select_wd_register();
outb_p(0xF6, WDT_EFER); /* Select CRF6 */
timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */
w83627hf_unselect_wd_register();
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");
if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", wdt_io);
return -EIO;
}
watchdog_init_timeout(&wdt_dev, timeout, NULL);
watchdog_set_nowayout(&wdt_dev, nowayout);
w83627hf_init(&wdt_dev);
ret = register_reboot_notifier(&wdt_notifier);
if (ret != 0) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
goto unreg_regions;
}
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);
unreg_regions:
release_region(wdt_io, 1);
return ret;
}
static void __exit wdt_exit(void)
{
watchdog_unregister_device(&wdt_dev);
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");
