[linux.git] / drivers / watchdog / w83627hf_wdt.c

/*
 *	w83627hf/thf WDT driver
 *
 *	(c) Copyright 2007 Vlad Drukker <[email protected]>
 *		added support for W83627THF.
 *
 *	(c) Copyright 2003,2007 Pádraig Brady <[email protected]>
 *
 *	Based on advantechwdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 2000-2001 Marek Michalkiewicz <[email protected]>
 *
 *	(c) Copyright 1996 Alan Cox <[email protected]>,
 *						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 <[email protected]>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/io.h>
#include <linux/uaccess.h>


#define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
#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 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)
{
	unsigned char c;
	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
	outb_p(0x87, WDT_EFER); /* Again according to manual */
Commit	Line	Data
1da177e4	1	/*
0e94f2ee VD	2	* w83627hf/thf WDT driver
	3	*
	4	* (c) Copyright 2007 Vlad Drukker <[email protected]>
	5	* added support for W83627THF.
1da177e4	6	*
d36b6910	7	* (c) Copyright 2003,2007 Pádraig Brady <[email protected]>
1da177e4 LT	8	*
	9	* Based on advantechwdt.c which is based on wdt.c.
	10	* Original copyright messages:
	11	*
	12	* (c) Copyright 2000-2001 Marek Michalkiewicz <[email protected]>
	13	*
29fa0586 AC	14	* (c) Copyright 1996 Alan Cox <[email protected]>,
29fa0586 AC	15	* All Rights Reserved.
1da177e4 LT	16	*
	17	* This program is free software; you can redistribute it and/or
	18	* modify it under the terms of the GNU General Public License
	19	* as published by the Free Software Foundation; either version
	20	* 2 of the License, or (at your option) any later version.
	21	*
	22	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	23	* warranty for any of this software. This material is provided
	24	* "AS-IS" and at no charge.
	25	*
29fa0586	26	* (c) Copyright 1995 Alan Cox <[email protected]>
1da177e4 LT	27	*/
1da177e4 LT	28
27c766aa JP	29	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	30
1da177e4 LT	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/types.h>
	34	#include <linux/miscdevice.h>
	35	#include <linux/watchdog.h>
	36	#include <linux/fs.h>
	37	#include <linux/ioport.h>
	38	#include <linux/notifier.h>
	39	#include <linux/reboot.h>
	40	#include <linux/init.h>
ab9d4414	41	#include <linux/spinlock.h>
46a3949d AC	42	#include <linux/io.h>
46a3949d AC	43	#include <linux/uaccess.h>
1da177e4	44
1da177e4	45
9c67bea4	46	#define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
1da177e4 LT	47	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
	48
	49	static unsigned long wdt_is_open;
	50	static char expect_close;
c7dfd0cc	51	static DEFINE_SPINLOCK(io_lock);
1da177e4 LT	52
	53	/* You must set this - there is no sane way to probe for this board. */
	54	static int wdt_io = 0x2E;
	55	module_param(wdt_io, int, 0);
0e94f2ee	56	MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)");
1da177e4 LT	57
	58	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	59	module_param(timeout, int, 0);
46a3949d AC	60	MODULE_PARM_DESC(timeout,
	61	"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
	62	__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4	63
86a1e189 WVS	64	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	65	module_param(nowayout, bool, 0);
46a3949d AC	66	MODULE_PARM_DESC(nowayout,
	67	"Watchdog cannot be stopped once started (default="
	68	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	69
	70	/*
	71	* Kernel methods.
	72	*/
	73
	74	#define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
46a3949d AC	75	#define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
46a3949d AC	76	(same as EFER) */
1da177e4 LT	77	#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
1da177e4 LT	78
46a3949d	79	static void w83627hf_select_wd_register(void)
1da177e4	80	{
0e94f2ee	81	unsigned char c;
1da177e4 LT	82	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
	83	outb_p(0x87, WDT_EFER); /* Again according to manual */
	84