[deliverable/linux.git] / drivers / watchdog / pc87413_wdt.c

/*
 *      NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
 *
 *      This code is based on wdt.c with original copyright.
 *
 *      (C) Copyright 2006 Sven Anders, <anders@anduras.de>
 *                     and Marcus Junker, <junker@anduras.de>
 *
 *      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 Sven Anders, Marcus Junker nor ANDURAS AG
 *      admit liability nor provide warranty for any of this software.
 *      This material is provided "AS-IS" and at no charge.
 *
 *      Release 1.1
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <asm/system.h>

/* #define DEBUG 1 */

#define DEFAULT_TIMEOUT     1		/* 1 minute */
#define MAX_TIMEOUT         255

#define VERSION             "1.1"
#define MODNAME             "pc87413 WDT"
#define PFX                 MODNAME ": "
#define DPFX                MODNAME " - DEBUG: "

#define WDT_INDEX_IO_PORT   (io+0)	/* I/O port base (index register) */
#define WDT_DATA_IO_PORT    (WDT_INDEX_IO_PORT+1)
#define SWC_LDN             0x04
#define SIOCFG2             0x22	/* Serial IO register */
#define WDCTL               0x10	/* Watchdog-Timer-Controll-Register */
#define WDTO                0x11	/* Watchdog timeout register */
#define WDCFG               0x12	/* Watchdog config register */

#define IO_DEFAULT	0x2E		/* Address used on Portwell Boards */

static int io = IO_DEFAULT;

static int timeout = DEFAULT_TIMEOUT;	/* timeout value */
static unsigned long timer_enabled;	/* is the timer enabled? */

static char expect_close;		/* is the close expected? */

static DEFINE_SPINLOCK(io_lock);	/* to guard us from io races */

static int nowayout = WATCHDOG_NOWAYOUT;

/* -- Low level function ----------------------------------------*/

/* Select pins for Watchdog output */

static inline void pc87413_select_wdt_out(void)
{
	unsigned int cr_data = 0;

	/* Step 1: Select multiple pin,pin55,as WDT output */

	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);

	cr_data = inb(WDT_DATA_IO_PORT);

	cr_data |= 0x80; /* Set Bit7 to 1*/
	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);

	outb_p(cr_data, WDT_DATA_IO_PORT);

#ifdef DEBUG
	printk(KERN_INFO DPFX
		"Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
								cr_data);
#endif
}

/* Enable SWC functions */

static inline void pc87413_enable_swc(void)
{
	unsigned int cr_data = 0;

	/* Step 2: Enable SWC functions */

	outb_p(0x07, WDT_INDEX_IO_PORT);	/* Point SWC_LDN (LDN=4) */
	outb_p(SWC_LDN, WDT_DATA_IO_PORT);

	outb_p(0x30, WDT_INDEX_IO_PORT);	/* Read Index 0x30 First */
	cr_data = inb(WDT_DATA_IO_PORT);
	cr_data |= 0x01;			/* Set Bit0 to 1 */
	outb_p(0x30, WDT_INDEX_IO_PORT);
	outb_p(cr_data, WDT_DATA_IO_PORT);	/* Index0x30_bit0P1 */

#ifdef DEBUG
	printk(KERN_INFO DPFX "pc87413 - Enable SWC functions\n");
#endif
}

/* Read SWC I/O base address */

static inline unsigned int pc87413_get_swc_base(void)
{
	unsigned int  swc_base_addr = 0;
	unsigned char addr_l, addr_h = 0;

	/* Step 3: Read SWC I/O Base Address */

	outb_p(0x60, WDT_INDEX_IO_PORT);	/* Read Index 0x60 */
	addr_h = inb(WDT_DATA_IO_PORT);

	outb_p(0x61, WDT_INDEX_IO_PORT);	/* Read Index 0x61 */

	addr_l = inb(WDT_DATA_IO_PORT);

	swc_base_addr = (addr_h << 8) + addr_l;
#ifdef DEBUG
	printk(KERN_INFO DPFX
		"Read SWC I/O Base Address: low %d, high %d, res %d\n",
						addr_l, addr_h, swc_base_addr);
#endif
	return swc_base_addr;
}

/* Select Bank 3 of SWC */

static inline void pc87413_swc_bank3(unsigned int swc_base_addr)
{
	/* Step 4: Select Bank3 of SWC */
	outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
#ifdef DEBUG
	printk(KERN_INFO DPFX "Select Bank3 of SWC\n");
#endif
}

/* Set watchdog timeout to x minutes */

static inline void pc87413_programm_wdto(unsigned int swc_base_addr,
					 char pc87413_time)
{
	/* Step 5: Programm WDTO, Twd. */
	outb_p(pc87413_time, swc_base_addr + WDTO);
#ifdef DEBUG
	printk(KERN_INFO DPFX "Set WDTO to %d minutes\n", pc87413_time);
#endif
}

/* Enable WDEN */

static inline void pc87413_enable_wden(unsigned int swc_base_addr)
{
	/* Step 6: Enable WDEN */
	outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
#ifdef DEBUG
	printk(KERN_INFO DPFX "Enable WDEN\n");
#endif
}

/* Enable SW_WD_TREN */
static inline void pc87413_enable_sw_wd_tren(unsigned int swc_base_addr)
{
	/* Enable SW_WD_TREN */
	outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
#ifdef DEBUG
	printk(KERN_INFO DPFX "Enable SW_WD_TREN\n");
#endif
}

/* Disable SW_WD_TREN */

static inline void pc87413_disable_sw_wd_tren(unsigned int swc_base_addr)
{
	/* Disable SW_WD_TREN */
	outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
#ifdef DEBUG
	printk(KERN_INFO DPFX "pc87413 - Disable SW_WD_TREN\n");
#endif
}

/* Enable SW_WD_TRG */

static inline void pc87413_enable_sw_wd_trg(unsigned int swc_base_addr)
{
	/* Enable SW_WD_TRG */
	outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
#ifdef DEBUG
	printk(KERN_INFO DPFX "pc87413 - Enable SW_WD_TRG\n");
#endif
}

/* Disable SW_WD_TRG */

static inline void pc87413_disable_sw_wd_trg(unsigned int swc_base_addr)
{
	/* Disable SW_WD_TRG */
	outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
#ifdef DEBUG
	printk(KERN_INFO DPFX "Disable SW_WD_TRG\n");
#endif
}

/* -- Higher level functions ------------------------------------*/

/* Enable the watchdog */

static void pc87413_enable(void)
{
	unsigned int swc_base_addr;

	spin_lock(&io_lock);

	pc87413_select_wdt_out();
	pc87413_enable_swc();
	swc_base_addr = pc87413_get_swc_base();
	pc87413_swc_bank3(swc_base_addr);
	pc87413_programm_wdto(swc_base_addr, timeout);
	pc87413_enable_wden(swc_base_addr);
	pc87413_enable_sw_wd_tren(swc_base_addr);
	pc87413_enable_sw_wd_trg(swc_base_addr);

	spin_unlock(&io_lock);
}

/* Disable the watchdog */

static void pc87413_disable(void)
{
	unsigned int swc_base_addr;

	spin_lock(&io_lock);

	pc87413_select_wdt_out();
	pc87413_enable_swc();
	swc_base_addr = pc87413_get_swc_base();
	pc87413_swc_bank3(swc_base_addr);
	pc87413_disable_sw_wd_tren(swc_base_addr);
	pc87413_disable_sw_wd_trg(swc_base_addr);
	pc87413_programm_wdto(swc_base_addr, 0);

	spin_unlock(&io_lock);
}

/* Refresh the watchdog */

static void pc87413_refresh(void)
{
	unsigned int swc_base_addr;

	spin_lock(&io_lock);

	pc87413_select_wdt_out();
	pc87413_enable_swc();
	swc_base_addr = pc87413_get_swc_base();
	pc87413_swc_bank3(swc_base_addr);
	pc87413_disable_sw_wd_tren(swc_base_addr);
	pc87413_disable_sw_wd_trg(swc_base_addr);
	pc87413_programm_wdto(swc_base_addr, timeout);
	pc87413_enable_wden(swc_base_addr);
	pc87413_enable_sw_wd_tren(swc_base_addr);
	pc87413_enable_sw_wd_trg(swc_base_addr);

	spin_unlock(&io_lock);
}

/* -- File operations -------------------------------------------*/

/**
 *	pc87413_open:
 *	@inode: inode of device
 *	@file: file handle to device
 *
 */

static int pc87413_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */

	if (test_and_set_bit(0, &timer_enabled))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Reload and activate timer */
	pc87413_refresh();

	printk(KERN_INFO MODNAME
		"Watchdog enabled. Timeout set to %d minute(s).\n", timeout);

	return nonseekable_open(inode, file);
}

/**
 *	pc87413_release:
 *	@inode: inode to board
 *	@file: file handle to board
 *
 *	The watchdog has a configurable API. There is a religious dispute
 *	between people who want their watchdog to be able to shut down and
 *	those who want to be sure if the watchdog manager dies the machine
 *	reboots. In the former case we disable the counters, in the latter
 *	case you have to open it again very soon.
 */

static int pc87413_release(struct inode *inode, struct file *file)
{
	/* Shut off the timer. */

	if (expect_close == 42) {
		pc87413_disable();
		printk(KERN_INFO MODNAME
				"Watchdog disabled, sleeping again...\n");
	} else {
		printk(KERN_CRIT MODNAME
				"Unexpected close, not stopping watchdog!\n");
		pc87413_refresh();
	}
	clear_bit(0, &timer_enabled);
	expect_close = 0;
	return 0;
}

/**
 *	pc87413_status:
 *
 *      return, if the watchdog is enabled (timeout is set...)
 */


static int pc87413_status(void)
{
	  return 0; /* currently not supported */
}

/**
 *	pc87413_write:
 *	@file: file handle to the watchdog
 *	@data: data buffer to write
 *	@len: length in bytes
 *	@ppos: pointer to the position to write. No seeks allowed
 *
 *	A write to a watchdog device is defined as a keepalive signal. Any
 *	write of data will do, as we we don't define content meaning.
 */

static ssize_t pc87413_write(struct file *file, const char __user *data,
			     size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* reset expect flag */
			expect_close = 0;

			/* scan to see whether or not we got the
			   magic character */
			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		pc87413_refresh();
	}
	return len;
}

/**
 *	pc87413_ioctl:
 *	@file: file handle to the device
 *	@cmd: watchdog command
 *	@arg: argument pointer
 *
 *	The watchdog API defines a common set of functions for all watchdogs
 *	according to their available features. We only actually usefully support
 *	querying capabilities and current status.
 */

static long pc87413_ioctl(struct file *file, unsigned int cmd,
						unsigned long arg)
{
	int new_timeout;

	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	static const struct watchdog_info ident = {
		.options          = WDIOF_KEEPALIVEPING |
				    WDIOF_SETTIMEOUT |
				    WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity         = "PC87413(HF/F) watchdog",
	};

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &ident,
					sizeof(ident)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
		return put_user(pc87413_status(), uarg.i);
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);
	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;
		if (get_user(options, uarg.i))
			return -EFAULT;
		if (options & WDIOS_DISABLECARD) {
			pc87413_disable();
			retval = 0;
		}
		if (options & WDIOS_ENABLECARD) {
			pc87413_enable();
			retval = 0;
		}
		return retval;
	}
	case WDIOC_KEEPALIVE:
		pc87413_refresh();
#ifdef DEBUG
		printk(KERN_INFO DPFX "keepalive\n");
#endif
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;
		/* the API states this is given in secs */
		new_timeout /= 60;
		if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
			return -EINVAL;
		timeout = new_timeout;
		pc87413_refresh();
		/* fall through and return the new timeout... */
	case WDIOC_GETTIMEOUT:
		new_timeout = timeout * 60;
		return put_user(new_timeout, uarg.i);
	default:
		return -ENOTTY;
	}
}

/* -- Notifier funtions -----------------------------------------*/

/**
 *	notify_sys:
 *	@this: our notifier block
 *	@code: the event being reported
 *	@unused: unused
 *
 *	Our notifier is called on system shutdowns. We want to turn the card
 *	off at reboot otherwise the machine will reboot again during memory
 *	test or worse yet during the following fsck. This would suck, in fact
 *	trust me - if it happens it does suck.
 */

static int pc87413_notify_sys(struct notifier_block *this,
			      unsigned long code,
			      void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		/* Turn the card off */
		pc87413_disable();
	return NOTIFY_DONE;
}

/* -- Module's structures ---------------------------------------*/

static const struct file_operations pc87413_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= pc87413_write,
	.unlocked_ioctl	= pc87413_ioctl,
	.open		= pc87413_open,
	.release	= pc87413_release,
};

static struct notifier_block pc87413_notifier = {
	.notifier_call  = pc87413_notify_sys,
};

static struct miscdevice pc87413_miscdev = {
	.minor          = WATCHDOG_MINOR,
	.name           = "watchdog",
	.fops           = &pc87413_fops,
};

/* -- Module init functions -------------------------------------*/

/**
 * 	pc87413_init: module's "constructor"
 *
 *	Set up the WDT watchdog board. All we have to do is grab the
 *	resources we require and bitch if anyone beat us to them.
 *	The open() function will actually kick the board off.
 */

static int __init pc87413_init(void)
{
	int ret;

	printk(KERN_INFO PFX "Version " VERSION " at io 0x%X\n",
							WDT_INDEX_IO_PORT);

	/* request_region(io, 2, "pc87413"); */

	ret = register_reboot_notifier(&pc87413_notifier);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", ret);
	}

	ret = misc_register(&pc87413_miscdev);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		unregister_reboot_notifier(&pc87413_notifier);
		return ret;
	}
	printk(KERN_INFO PFX "initialized. timeout=%d min \n", timeout);
	pc87413_enable();
	return 0;
}

/**
 *	pc87413_exit: module's "destructor"
 *
 *	Unload the watchdog. You cannot do this with any file handles open.
 *	If your watchdog is set to continue ticking on close and you unload
 *	it, well it keeps ticking. We won't get the interrupt but the board
 *	will not touch PC memory so all is fine. You just have to load a new
 *	module in 60 seconds or reboot.
 */

static void __exit pc87413_exit(void)
{
	/* Stop the timer before we leave */
	if (!nowayout) {
		pc87413_disable();
		printk(KERN_INFO MODNAME "Watchdog disabled.\n");
	}

	misc_deregister(&pc87413_miscdev);
	unregister_reboot_notifier(&pc87413_notifier);
	/* release_region(io, 2); */

	printk(KERN_INFO MODNAME " watchdog component driver removed.\n");
}

module_init(pc87413_init);
module_exit(pc87413_exit);

MODULE_AUTHOR("Sven Anders <anders@anduras.de>, "
		"Marcus Junker <junker@anduras.de>,");
MODULE_DESCRIPTION("PC87413 WDT driver");
MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(io, int, 0);
MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
					__MODULE_STRING(IO_DEFAULT) ").");

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in minutes (default="
				__MODULE_STRING(DEFAULT_TIMEOUT) ").");

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Commit	Line	Data
	1	/*
	2	* NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
	3	*
	4	* This code is based on wdt.c with original copyright.
	5	*
	6	* (C) Copyright 2006 Sven Anders, <anders@anduras.de>
	7	* and Marcus Junker, <junker@anduras.de>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* Neither Sven Anders, Marcus Junker nor ANDURAS AG
	15	* admit liability nor provide warranty for any of this software.
	16	* This material is provided "AS-IS" and at no charge.
	17	*
	18	* Release 1.1
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/types.h>
	23	#include <linux/miscdevice.h>
	24	#include <linux/watchdog.h>
	25	#include <linux/ioport.h>
	26	#include <linux/delay.h>
	27	#include <linux/notifier.h>
	28	#include <linux/fs.h>
	29	#include <linux/reboot.h>
	30	#include <linux/init.h>
	31	#include <linux/spinlock.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/io.h>
	34	#include <linux/uaccess.h>
	35
	36	#include <asm/system.h>
	37
	38	/* #define DEBUG 1 */
	39
	40	#define DEFAULT_TIMEOUT 1 /* 1 minute */
	41	#define MAX_TIMEOUT 255
	42
	43	#define VERSION "1.1"
	44	#define MODNAME "pc87413 WDT"
	45	#define PFX MODNAME ": "
	46	#define DPFX MODNAME " - DEBUG: "
	47
	48	#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */
	49	#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1)
	50	#define SWC_LDN 0x04
	51	#define SIOCFG2 0x22 /* Serial IO register */
	52	#define WDCTL 0x10 /* Watchdog-Timer-Controll-Register */
	53	#define WDTO 0x11 /* Watchdog timeout register */
	54	#define WDCFG 0x12 /* Watchdog config register */
	55
	56	#define IO_DEFAULT 0x2E /* Address used on Portwell Boards */
	57
	58	static int io = IO_DEFAULT;
	59
	60	static int timeout = DEFAULT_TIMEOUT; /* timeout value */
	61	static unsigned long timer_enabled; /* is the timer enabled? */
	62
	63	static char expect_close; /* is the close expected? */
	64
	65	static DEFINE_SPINLOCK(io_lock); /* to guard us from io races */
	66
	67	static int nowayout = WATCHDOG_NOWAYOUT;
	68
	69	/* -- Low level function ----------------------------------------*/
	70
	71	/* Select pins for Watchdog output */
	72
	73	static inline void pc87413_select_wdt_out(void)
	74	{
	75	unsigned int cr_data = 0;
	76
	77	/* Step 1: Select multiple pin,pin55,as WDT output */
	78
	79	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
	80
	81	cr_data = inb(WDT_DATA_IO_PORT);
	82
	83	cr_data \|= 0x80; /* Set Bit7 to 1*/
	84	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
	85
	86	outb_p(cr_data, WDT_DATA_IO_PORT);
	87
	88	#ifdef DEBUG
	89	printk(KERN_INFO DPFX
	90	"Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
	91	cr_data);
	92	#endif
	93	}
	94
	95	/* Enable SWC functions */
	96
	97	static inline void pc87413_enable_swc(void)
	98	{
	99	unsigned int cr_data = 0;
	100
	101	/* Step 2: Enable SWC functions */
	102
	103	outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */
	104	outb_p(SWC_LDN, WDT_DATA_IO_PORT);
	105
	106	outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */
	107	cr_data = inb(WDT_DATA_IO_PORT);
	108	cr_data \|= 0x01; /* Set Bit0 to 1 */
	109	outb_p(0x30, WDT_INDEX_IO_PORT);
	110	outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */
	111
	112	#ifdef DEBUG
	113	printk(KERN_INFO DPFX "pc87413 - Enable SWC functions\n");
	114	#endif
	115	}
	116
	117	/* Read SWC I/O base address */
	118
	119	static inline unsigned int pc87413_get_swc_base(void)
	120	{
	121	unsigned int swc_base_addr = 0;
	122	unsigned char addr_l, addr_h = 0;
	123
	124	/* Step 3: Read SWC I/O Base Address */
	125
	126	outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */
	127	addr_h = inb(WDT_DATA_IO_PORT);
	128
	129	outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */
	130
	131	addr_l = inb(WDT_DATA_IO_PORT);
	132
	133	swc_base_addr = (addr_h << 8) + addr_l;
	134	#ifdef DEBUG
	135	printk(KERN_INFO DPFX
	136	"Read SWC I/O Base Address: low %d, high %d, res %d\n",
	137	addr_l, addr_h, swc_base_addr);
	138	#endif
	139	return swc_base_addr;
	140	}
	141
	142	/* Select Bank 3 of SWC */
	143
	144	static inline void pc87413_swc_bank3(unsigned int swc_base_addr)
	145	{
	146	/* Step 4: Select Bank3 of SWC */
	147	outb_p(inb(swc_base_addr + 0x0f) \| 0x03, swc_base_addr + 0x0f);
	148	#ifdef DEBUG
	149	printk(KERN_INFO DPFX "Select Bank3 of SWC\n");
	150	#endif
	151	}
	152
	153	/* Set watchdog timeout to x minutes */
	154
	155	static inline void pc87413_programm_wdto(unsigned int swc_base_addr,
	156	char pc87413_time)
	157	{
	158	/* Step 5: Programm WDTO, Twd. */
	159	outb_p(pc87413_time, swc_base_addr + WDTO);
	160	#ifdef DEBUG
	161	printk(KERN_INFO DPFX "Set WDTO to %d minutes\n", pc87413_time);
	162	#endif
	163	}
	164
	165	/* Enable WDEN */
	166
	167	static inline void pc87413_enable_wden(unsigned int swc_base_addr)
	168	{
	169	/* Step 6: Enable WDEN */
	170	outb_p(inb(swc_base_addr + WDCTL) \| 0x01, swc_base_addr + WDCTL);
	171	#ifdef DEBUG
	172	printk(KERN_INFO DPFX "Enable WDEN\n");
	173	#endif
	174	}
	175
	176	/* Enable SW_WD_TREN */
	177	static inline void pc87413_enable_sw_wd_tren(unsigned int swc_base_addr)
	178	{
	179	/* Enable SW_WD_TREN */
	180	outb_p(inb(swc_base_addr + WDCFG) \| 0x80, swc_base_addr + WDCFG);
	181	#ifdef DEBUG
	182	printk(KERN_INFO DPFX "Enable SW_WD_TREN\n");
	183	#endif
	184	}
	185
	186	/* Disable SW_WD_TREN */
	187
	188	static inline void pc87413_disable_sw_wd_tren(unsigned int swc_base_addr)
	189	{
	190	/* Disable SW_WD_TREN */
	191	outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
	192	#ifdef DEBUG
	193	printk(KERN_INFO DPFX "pc87413 - Disable SW_WD_TREN\n");
	194	#endif
	195	}
	196
	197	/* Enable SW_WD_TRG */
	198
	199	static inline void pc87413_enable_sw_wd_trg(unsigned int swc_base_addr)
	200	{
	201	/* Enable SW_WD_TRG */
	202	outb_p(inb(swc_base_addr + WDCTL) \| 0x80, swc_base_addr + WDCTL);
	203	#ifdef DEBUG
	204	printk(KERN_INFO DPFX "pc87413 - Enable SW_WD_TRG\n");
	205	#endif
	206	}
	207
	208	/* Disable SW_WD_TRG */
	209
	210	static inline void pc87413_disable_sw_wd_trg(unsigned int swc_base_addr)
	211	{
	212	/* Disable SW_WD_TRG */
	213	outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
	214	#ifdef DEBUG
	215	printk(KERN_INFO DPFX "Disable SW_WD_TRG\n");
	216	#endif
	217	}
	218
	219	/* -- Higher level functions ------------------------------------*/
	220
	221	/* Enable the watchdog */
	222
	223	static void pc87413_enable(void)
	224	{
	225	unsigned int swc_base_addr;
	226
	227	spin_lock(&io_lock);
	228
	229	pc87413_select_wdt_out();
	230	pc87413_enable_swc();
	231	swc_base_addr = pc87413_get_swc_base();
	232	pc87413_swc_bank3(swc_base_addr);
	233	pc87413_programm_wdto(swc_base_addr, timeout);
	234	pc87413_enable_wden(swc_base_addr);
	235	pc87413_enable_sw_wd_tren(swc_base_addr);
	236	pc87413_enable_sw_wd_trg(swc_base_addr);
	237
	238	spin_unlock(&io_lock);
	239	}
	240
	241	/* Disable the watchdog */
	242
	243	static void pc87413_disable(void)
	244	{
	245	unsigned int swc_base_addr;
	246
	247	spin_lock(&io_lock);
	248
	249	pc87413_select_wdt_out();
	250	pc87413_enable_swc();
	251	swc_base_addr = pc87413_get_swc_base();
	252	pc87413_swc_bank3(swc_base_addr);
	253	pc87413_disable_sw_wd_tren(swc_base_addr);
	254	pc87413_disable_sw_wd_trg(swc_base_addr);
	255	pc87413_programm_wdto(swc_base_addr, 0);
	256
	257	spin_unlock(&io_lock);
	258	}
	259
	260	/* Refresh the watchdog */
	261
	262	static void pc87413_refresh(void)
	263	{
	264	unsigned int swc_base_addr;
	265
	266	spin_lock(&io_lock);
	267
	268	pc87413_select_wdt_out();
	269	pc87413_enable_swc();
	270	swc_base_addr = pc87413_get_swc_base();
	271	pc87413_swc_bank3(swc_base_addr);
	272	pc87413_disable_sw_wd_tren(swc_base_addr);
	273	pc87413_disable_sw_wd_trg(swc_base_addr);
	274	pc87413_programm_wdto(swc_base_addr, timeout);
	275	pc87413_enable_wden(swc_base_addr);
	276	pc87413_enable_sw_wd_tren(swc_base_addr);
	277	pc87413_enable_sw_wd_trg(swc_base_addr);
	278
	279	spin_unlock(&io_lock);
	280	}
	281
	282	/* -- File operations -------------------------------------------*/
	283
	284	/**
	285	* pc87413_open:
	286	* @inode: inode of device
	287	* @file: file handle to device
	288	*
	289	*/
	290
	291	static int pc87413_open(struct inode inode, struct file file)
	292	{
	293	/* /dev/watchdog can only be opened once */
	294
	295	if (test_and_set_bit(0, &timer_enabled))
	296	return -EBUSY;
	297
	298	if (nowayout)
	299	__module_get(THIS_MODULE);
	300
	301	/* Reload and activate timer */
	302	pc87413_refresh();
	303
	304	printk(KERN_INFO MODNAME
	305	"Watchdog enabled. Timeout set to %d minute(s).\n", timeout);
	306
	307	return nonseekable_open(inode, file);
	308	}
	309
	310	/**
	311	* pc87413_release:
	312	* @inode: inode to board
	313	* @file: file handle to board
	314	*
	315	* The watchdog has a configurable API. There is a religious dispute
	316	* between people who want their watchdog to be able to shut down and
	317	* those who want to be sure if the watchdog manager dies the machine
	318	* reboots. In the former case we disable the counters, in the latter
	319	* case you have to open it again very soon.
	320	*/
	321
	322	static int pc87413_release(struct inode inode, struct file file)
	323	{
	324	/* Shut off the timer. */
	325
	326	if (expect_close == 42) {
	327	pc87413_disable();
	328	printk(KERN_INFO MODNAME
	329	"Watchdog disabled, sleeping again...\n");
	330	} else {
	331	printk(KERN_CRIT MODNAME
	332	"Unexpected close, not stopping watchdog!\n");
	333	pc87413_refresh();
	334	}
	335	clear_bit(0, &timer_enabled);
	336	expect_close = 0;
	337	return 0;
	338	}
	339
	340	/**
	341	* pc87413_status:
	342	*
	343	* return, if the watchdog is enabled (timeout is set...)
	344	*/
	345
	346
	347	static int pc87413_status(void)
	348	{
	349	return 0; /* currently not supported */
	350	}
	351
	352	/**
	353	* pc87413_write:
	354	* @file: file handle to the watchdog
	355	* @data: data buffer to write
	356	* @len: length in bytes
	357	* @ppos: pointer to the position to write. No seeks allowed
	358	*
	359	* A write to a watchdog device is defined as a keepalive signal. Any
	360	* write of data will do, as we we don't define content meaning.
	361	*/
	362
	363	static ssize_t pc87413_write(struct file file, const char __user data,
	364	size_t len, loff_t *ppos)
	365	{
	366	/* See if we got the magic character 'V' and reload the timer */
	367	if (len) {
	368	if (!nowayout) {
	369	size_t i;
	370
	371	/* reset expect flag */
	372	expect_close = 0;
	373
	374	/* scan to see whether or not we got the
	375	magic character */
	376	for (i = 0; i != len; i++) {
	377	char c;
	378	if (get_user(c, data + i))
	379	return -EFAULT;
	380	if (c == 'V')
	381	expect_close = 42;
	382	}
	383	}
	384
	385	/* someone wrote to us, we should reload the timer */
	386	pc87413_refresh();
	387	}
	388	return len;
	389	}
	390
	391	/**
	392	* pc87413_ioctl:
	393	* @file: file handle to the device
	394	* @cmd: watchdog command
	395	* @arg: argument pointer
	396	*
	397	* The watchdog API defines a common set of functions for all watchdogs
	398	* according to their available features. We only actually usefully support
	399	* querying capabilities and current status.
	400	*/
	401
	402	static long pc87413_ioctl(struct file *file, unsigned int cmd,
	403	unsigned long arg)
	404	{
	405	int new_timeout;
	406
	407	union {
	408	struct watchdog_info __user *ident;
	409	int __user *i;
	410	} uarg;
	411
	412	static const struct watchdog_info ident = {
	413	.options = WDIOF_KEEPALIVEPING \|
	414	WDIOF_SETTIMEOUT \|
	415	WDIOF_MAGICCLOSE,
	416	.firmware_version = 1,
	417	.identity = "PC87413(HF/F) watchdog",
	418	};
	419
	420	uarg.i = (int __user *)arg;
	421
	422	switch (cmd) {
	423	case WDIOC_GETSUPPORT:
	424	return copy_to_user(uarg.ident, &ident,
	425	sizeof(ident)) ? -EFAULT : 0;
	426	case WDIOC_GETSTATUS:
	427	return put_user(pc87413_status(), uarg.i);
	428	case WDIOC_GETBOOTSTATUS:
	429	return put_user(0, uarg.i);
	430	case WDIOC_SETOPTIONS:
	431	{
	432	int options, retval = -EINVAL;
	433	if (get_user(options, uarg.i))
	434	return -EFAULT;
	435	if (options & WDIOS_DISABLECARD) {
	436	pc87413_disable();
	437	retval = 0;
	438	}
	439	if (options & WDIOS_ENABLECARD) {
	440	pc87413_enable();
	441	retval = 0;
	442	}
	443	return retval;
	444	}
	445	case WDIOC_KEEPALIVE:
	446	pc87413_refresh();
	447	#ifdef DEBUG
	448	printk(KERN_INFO DPFX "keepalive\n");
	449	#endif
	450	return 0;
	451	case WDIOC_SETTIMEOUT:
	452	if (get_user(new_timeout, uarg.i))
	453	return -EFAULT;
	454	/* the API states this is given in secs */
	455	new_timeout /= 60;
	456	if (new_timeout < 0 \|\| new_timeout > MAX_TIMEOUT)
	457	return -EINVAL;
	458	timeout = new_timeout;
	459	pc87413_refresh();
	460	/* fall through and return the new timeout... */
	461	case WDIOC_GETTIMEOUT:
	462	new_timeout = timeout * 60;
	463	return put_user(new_timeout, uarg.i);
	464	default:
	465	return -ENOTTY;
	466	}
	467	}
	468
	469	/* -- Notifier funtions -----------------------------------------*/
	470
	471	/**
	472	* notify_sys:
	473	* @this: our notifier block
	474	* @code: the event being reported
	475	* @unused: unused
	476	*
	477	* Our notifier is called on system shutdowns. We want to turn the card
	478	* off at reboot otherwise the machine will reboot again during memory
	479	* test or worse yet during the following fsck. This would suck, in fact
	480	* trust me - if it happens it does suck.
	481	*/
	482
	483	static int pc87413_notify_sys(struct notifier_block *this,
	484	unsigned long code,
	485	void *unused)
	486	{
	487	if (code == SYS_DOWN \|\| code == SYS_HALT)
	488	/* Turn the card off */
	489	pc87413_disable();
	490	return NOTIFY_DONE;
	491	}
	492
	493	/* -- Module's structures ---------------------------------------*/
	494
	495	static const struct file_operations pc87413_fops = {
	496	.owner = THIS_MODULE,
	497	.llseek = no_llseek,
	498	.write = pc87413_write,
	499	.unlocked_ioctl = pc87413_ioctl,
	500	.open = pc87413_open,
	501	.release = pc87413_release,
	502	};
	503
	504	static struct notifier_block pc87413_notifier = {
	505	.notifier_call = pc87413_notify_sys,
	506	};
	507
	508	static struct miscdevice pc87413_miscdev = {
	509	.minor = WATCHDOG_MINOR,
	510	.name = "watchdog",
	511	.fops = &pc87413_fops,
	512	};
	513
	514	/* -- Module init functions -------------------------------------*/
	515
	516	/**
	517	* pc87413_init: module's "constructor"
	518	*
	519	* Set up the WDT watchdog board. All we have to do is grab the
	520	* resources we require and bitch if anyone beat us to them.
	521	* The open() function will actually kick the board off.
	522	*/
	523
	524	static int __init pc87413_init(void)
	525	{
	526	int ret;
	527
	528	printk(KERN_INFO PFX "Version " VERSION " at io 0x%X\n",
	529	WDT_INDEX_IO_PORT);
	530
	531	/* request_region(io, 2, "pc87413"); */
	532
	533	ret = register_reboot_notifier(&pc87413_notifier);
	534	if (ret != 0) {
	535	printk(KERN_ERR PFX
	536	"cannot register reboot notifier (err=%d)\n", ret);
	537	}
	538
	539	ret = misc_register(&pc87413_miscdev);
	540	if (ret != 0) {
	541	printk(KERN_ERR PFX
	542	"cannot register miscdev on minor=%d (err=%d)\n",
	543	WATCHDOG_MINOR, ret);
	544	unregister_reboot_notifier(&pc87413_notifier);
	545	return ret;
	546	}
	547	printk(KERN_INFO PFX "initialized. timeout=%d min \n", timeout);
	548	pc87413_enable();
	549	return 0;
	550	}
	551
	552	/**
	553	* pc87413_exit: module's "destructor"
	554	*
	555	* Unload the watchdog. You cannot do this with any file handles open.
	556	* If your watchdog is set to continue ticking on close and you unload
	557	* it, well it keeps ticking. We won't get the interrupt but the board
	558	* will not touch PC memory so all is fine. You just have to load a new
	559	* module in 60 seconds or reboot.
	560	*/
	561
	562	static void __exit pc87413_exit(void)
	563	{
	564	/* Stop the timer before we leave */
	565	if (!nowayout) {
	566	pc87413_disable();
	567	printk(KERN_INFO MODNAME "Watchdog disabled.\n");
	568	}
	569
	570	misc_deregister(&pc87413_miscdev);
	571	unregister_reboot_notifier(&pc87413_notifier);
	572	/* release_region(io, 2); */
	573
	574	printk(KERN_INFO MODNAME " watchdog component driver removed.\n");
	575	}
	576
	577	module_init(pc87413_init);
	578	module_exit(pc87413_exit);
	579
	580	MODULE_AUTHOR("Sven Anders <anders@anduras.de>, "
	581	"Marcus Junker <junker@anduras.de>,");
	582	MODULE_DESCRIPTION("PC87413 WDT driver");
	583	MODULE_LICENSE("GPL");
	584
	585	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	586
	587	module_param(io, int, 0);
	588	MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
	589	__MODULE_STRING(IO_DEFAULT) ").");
	590
	591	module_param(timeout, int, 0);
	592	MODULE_PARM_DESC(timeout,
	593	"Watchdog timeout in minutes (default="
	594	__MODULE_STRING(DEFAULT_TIMEOUT) ").");
	595
	596	module_param(nowayout, int, 0);
	597	MODULE_PARM_DESC(nowayout,
	598	"Watchdog cannot be stopped once started (default="
	599	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	600