[deliverable/linux.git] / drivers / watchdog / w83977f_wdt.c

/*
 *	W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
 *
 *	(c) Copyright 2005  Jose Goncalves <jose.goncalves@inov.pt>
 *
 *      Based on w83877f_wdt.c by Scott Jennings,
 *           and wdt977.c by Woody Suwalski
 *
 *			-----------------------
 *
 *	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.
 *
 */

#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/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include <asm/system.h>

#define WATCHDOG_VERSION  "1.00"
#define WATCHDOG_NAME     "W83977F WDT"

#define IO_INDEX_PORT     0x3F0
#define IO_DATA_PORT      (IO_INDEX_PORT+1)

#define UNLOCK_DATA       0x87
#define LOCK_DATA         0xAA
#define DEVICE_REGISTER   0x07

#define	DEFAULT_TIMEOUT   45		/* default timeout in seconds */

static	int timeout = DEFAULT_TIMEOUT;
static	int timeoutW;			/* timeout in watchdog counter units */
static	unsigned long timer_alive;
static	int testmode;
static	char expect_close;
static	DEFINE_SPINLOCK(spinlock);

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds (15..7635), default="
				__MODULE_STRING(DEFAULT_TIMEOUT) ")");
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

/*
 * Start the watchdog
 */

static int wdt_start(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/*
	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	 * F2 has the timeout in watchdog counter units.
	 * F3 is set to enable watchdog LED blink at timeout.
	 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
	 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutW, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);

	/* Set device Aux2 active */
	outb_p(0x30, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);

	/*
	 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
	 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
	 * Map GP16 at pin 119.
	 * In test mode watch the bit 0 on F4 to indicate "triggered" or
	 * check watchdog LED on SBC.
	 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x07, IO_DATA_PORT);
	if (!testmode) {
		unsigned pin_map;

		outb_p(0xE6, IO_INDEX_PORT);
		outb_p(0x0A, IO_DATA_PORT);
		outb_p(0x2C, IO_INDEX_PORT);
		pin_map = inb_p(IO_DATA_PORT);
		pin_map |= 0x10;
		pin_map &= ~(0x20);
		outb_p(0x2C, IO_INDEX_PORT);
		outb_p(pin_map, IO_DATA_PORT);
	}
	outb_p(0xE3, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);

	/* Set device Aux1 active */
	outb_p(0x30, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);

	/* Lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);

	pr_info("activated\n");

	return 0;
}

/*
 * Stop the watchdog
 */

static int wdt_stop(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/*
	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	 * F2 is reset to its default value (watchdog timer disabled).
	 * F3 is reset to its default state.
	 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
	 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0xFF, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);

	/*
	 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
	 * Gp13 (in reg E3) as inputs.
	 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x07, IO_DATA_PORT);
	if (!testmode) {
		outb_p(0xE6, IO_INDEX_PORT);
		outb_p(0x01, IO_DATA_PORT);
	}
	outb_p(0xE3, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);

	/* Lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);

	pr_info("shutdown\n");

	return 0;
}

/*
 * Send a keepalive ping to the watchdog
 * This is done by simply re-writing the timeout to reg. 0xF2
 */

static int wdt_keepalive(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutW, IO_DATA_PORT);

	/* Lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);

	return 0;
}

/*
 * Set the watchdog timeout value
 */

static int wdt_set_timeout(int t)
{
	int tmrval;

	/*
	 * Convert seconds to watchdog counter time units, rounding up.
	 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
	 * value. This information is supplied in the PCM-5335 manual and was
	 * checked by me on a real board. This is a bit strange because W83977f
	 * datasheet says counter unit is in minutes!
	 */
	if (t < 15)
		return -EINVAL;

	tmrval = ((t + 15) + 29) / 30;

	if (tmrval > 255)
		return -EINVAL;

	/*
	 * timeout is the timeout in seconds,
	 * timeoutW is the timeout in watchdog counter units.
	 */
	timeoutW = tmrval;
	timeout = (timeoutW * 30) - 15;
	return 0;
}

/*
 * Get the watchdog status
 */

static int wdt_get_status(int *status)
{
	int new_status;
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* Select device Aux2 (device=8) to read watchdog reg F4 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	new_status = inb_p(IO_DATA_PORT);

	/* Lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);

	*status = 0;
	if (new_status & 1)
		*status |= WDIOF_CARDRESET;

	return 0;
}


/*
 *	/dev/watchdog handling
 */

static int wdt_open(struct inode *inode, struct file *file)
{
	/* If the watchdog is alive we don't need to start it again */
	if (test_and_set_bit(0, &timer_alive))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	wdt_start();
	return nonseekable_open(inode, file);
}

static int wdt_release(struct inode *inode, struct file *file)
{
	/*
	 * Shut off the timer.
	 * Lock it in if it's a module and we set nowayout
	 */
	if (expect_close == 42) {
		wdt_stop();
		clear_bit(0, &timer_alive);
	} else {
		wdt_keepalive();
		pr_crit("unexpected close, not stopping watchdog!\n");
	}
	expect_close = 0;
	return 0;
}

/*
 *      wdt_write:
 *      @file: file handle to the watchdog
 *      @buf: buffer to write (unused as data does not matter here
 *      @count: count of 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 wdt_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (count) {
		if (!nowayout) {
			size_t ofs;

			/* note: just in case someone wrote the
			   magic character long ago */
			expect_close = 0;

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

		/* someone wrote to us, we should restart timer */
		wdt_keepalive();
	}
	return count;
}

/*
 *      wdt_ioctl:
 *      @inode: inode of the device
 *      @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.
 */

static const struct watchdog_info ident = {
	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
	.firmware_version =	1,
	.identity = WATCHDOG_NAME,
};

static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	int status;
	int new_options, retval = -EINVAL;
	int new_timeout;
	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &ident,
						sizeof(ident)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
		wdt_get_status(&status);
		return put_user(status, uarg.i);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);

	case WDIOC_SETOPTIONS:
		if (get_user(new_options, uarg.i))
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD) {
			wdt_stop();
			retval = 0;
		}

		if (new_options & WDIOS_ENABLECARD) {
			wdt_start();
			retval = 0;
		}

		return retval;

	case WDIOC_KEEPALIVE:
		wdt_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;

		if (wdt_set_timeout(new_timeout))
			return -EINVAL;

		wdt_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(timeout, uarg.i);

	default:
		return -ENOTTY;

	}
}

static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt_stop();
	return NOTIFY_DONE;
}

static const struct file_operations wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wdt_write,
	.unlocked_ioctl	= wdt_ioctl,
	.open		= wdt_open,
	.release	= wdt_release,
};

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

static struct notifier_block wdt_notifier = {
	.notifier_call = wdt_notify_sys,
};

static int __init w83977f_wdt_init(void)
{
	int rc;

	pr_info("driver v%s\n", WATCHDOG_VERSION);

	/*
	 * Check that the timeout value is within it's range;
	 * if not reset to the default
	 */
	if (wdt_set_timeout(timeout)) {
		wdt_set_timeout(DEFAULT_TIMEOUT);
		pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n",
			DEFAULT_TIMEOUT);
	}

	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
		pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT);
		rc = -EIO;
		goto err_out;
	}

	rc = register_reboot_notifier(&wdt_notifier);
	if (rc) {
		pr_err("cannot register reboot notifier (err=%d)\n", rc);
		goto err_out_region;
	}

	rc = misc_register(&wdt_miscdev);
	if (rc) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       wdt_miscdev.minor, rc);
		goto err_out_reboot;
	}

	pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
		timeout, nowayout, testmode);

	return 0;

err_out_reboot:
	unregister_reboot_notifier(&wdt_notifier);
err_out_region:
	release_region(IO_INDEX_PORT, 2);
err_out:
	return rc;
}

static void __exit w83977f_wdt_exit(void)
{
	wdt_stop();
	misc_deregister(&wdt_miscdev);
	unregister_reboot_notifier(&wdt_notifier);
	release_region(IO_INDEX_PORT, 2);
}

module_init(w83977f_wdt_init);
module_exit(w83977f_wdt_exit);

MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
b4cc4aa2 JMG	1	/*
	2	* W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
	3	*
	4	* (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
	5	*
	6	* Based on w83877f_wdt.c by Scott Jennings,
	7	* and wdt977.c by Woody Suwalski
	8	*
	9	* -----------------------
	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*
	16	*/
	17
27c766aa JP	18	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	19
b4cc4aa2 JMG	20	#include <linux/module.h>
b4cc4aa2 JMG	21	#include <linux/moduleparam.h>
b4cc4aa2 JMG	22	#include <linux/types.h>
	23	#include <linux/kernel.h>
	24	#include <linux/fs.h>
	25	#include <linux/miscdevice.h>
	26	#include <linux/init.h>
	27	#include <linux/ioport.h>
	28	#include <linux/watchdog.h>
	29	#include <linux/notifier.h>
	30	#include <linux/reboot.h>
84af401a AC	31	#include <linux/uaccess.h>
84af401a AC	32	#include <linux/io.h>
b4cc4aa2	33
b4cc4aa2	34	#include <asm/system.h>
b4cc4aa2 JMG	35
	36	#define WATCHDOG_VERSION "1.00"
	37	#define WATCHDOG_NAME "W83977F WDT"
b4cc4aa2 JMG	38
	39	#define IO_INDEX_PORT 0x3F0
	40	#define IO_DATA_PORT (IO_INDEX_PORT+1)
	41
	42	#define UNLOCK_DATA 0x87
	43	#define LOCK_DATA 0xAA
	44	#define DEVICE_REGISTER 0x07
	45
	46	#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
	47
	48	static int timeout = DEFAULT_TIMEOUT;
	49	static int timeoutW; /* timeout in watchdog counter units */
	50	static unsigned long timer_alive;
	51	static int testmode;
	52	static char expect_close;
c7dfd0cc	53	static DEFINE_SPINLOCK(spinlock);
b4cc4aa2 JMG	54
b4cc4aa2 JMG	55	module_param(timeout, int, 0);
84af401a AC	56	MODULE_PARM_DESC(timeout,
	57	"Watchdog timeout in seconds (15..7635), default="
	58	__MODULE_STRING(DEFAULT_TIMEOUT) ")");
b4cc4aa2	59	module_param(testmode, int, 0);
84af401a	60	MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
b4cc4aa2	61
3908bb18	62	static int nowayout = WATCHDOG_NOWAYOUT;
b4cc4aa2	63	module_param(nowayout, int, 0);
84af401a AC	64	MODULE_PARM_DESC(nowayout,
	65	"Watchdog cannot be stopped once started (default="
	66	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b4cc4aa2 JMG	67
	68	/*
	69	* Start the watchdog
	70	*/
	71
	72	static int wdt_start(void)
	73	{
	74	unsigned long flags;
	75
	76	spin_lock_irqsave(&spinlock, flags);
	77
	78	/* Unlock the SuperIO chip */
84af401a AC	79	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	80	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	81
	82	/*
	83	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	84	* F2 has the timeout in watchdog counter units.
	85	* F3 is set to enable watchdog LED blink at timeout.
	86	* F4 is used to just clear the TIMEOUT'ed state (bit 0).
	87	*/
84af401a AC	88	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	89	outb_p(0x08, IO_DATA_PORT);
	90	outb_p(0xF2, IO_INDEX_PORT);
	91	outb_p(timeoutW, IO_DATA_PORT);
	92	outb_p(0xF3, IO_INDEX_PORT);
	93	outb_p(0x08, IO_DATA_PORT);
	94	outb_p(0xF4, IO_INDEX_PORT);
	95	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	96
b4cc4aa2 JMG	97	/* Set device Aux2 active */
84af401a AC	98	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	99	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	100
84af401a	101	/*
b4cc4aa2 JMG	102	* Select device Aux1 (dev=7) to set GP16 as the watchdog output
	103	* (in reg E6) and GP13 as the watchdog LED output (in reg E3).
	104	* Map GP16 at pin 119.
	105	* In test mode watch the bit 0 on F4 to indicate "triggered" or
	106	* check watchdog LED on SBC.
	107	*/
84af401a AC	108	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	109	outb_p(0x07, IO_DATA_PORT);
	110	if (!testmode) {
b4cc4aa2 JMG	111	unsigned pin_map;
b4cc4aa2 JMG	112
84af401a AC	113	outb_p(0xE6, IO_INDEX_PORT);
	114	outb_p(0x0A, IO_DATA_PORT);
	115	outb_p(0x2C, IO_INDEX_PORT);
b4cc4aa2 JMG	116	pin_map = inb_p(IO_DATA_PORT);
	117	pin_map \|= 0x10;
	118	pin_map &= ~(0x20);
84af401a AC	119	outb_p(0x2C, IO_INDEX_PORT);
84af401a AC	120	outb_p(pin_map, IO_DATA_PORT);
b4cc4aa2	121	}
84af401a AC	122	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	123	outb_p(0x08, IO_DATA_PORT);
b4cc4aa2 JMG	124
b4cc4aa2 JMG	125	/* Set device Aux1 active */
84af401a AC	126	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	127	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	128
b4cc4aa2 JMG	129	/* Lock the SuperIO chip */
84af401a	130	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	131
	132	spin_unlock_irqrestore(&spinlock, flags);
	133
27c766aa	134	pr_info("activated\n");
b4cc4aa2 JMG	135
	136	return 0;
	137	}
	138
	139	/*
	140	* Stop the watchdog
	141	*/
	142
	143	static int wdt_stop(void)
	144	{
	145	unsigned long flags;
	146
	147	spin_lock_irqsave(&spinlock, flags);
	148
	149	/* Unlock the SuperIO chip */
84af401a AC	150	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	151	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2	152
84af401a	153	/*
b4cc4aa2 JMG	154	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	155	* F2 is reset to its default value (watchdog timer disabled).
	156	* F3 is reset to its default state.
	157	* F4 clears the TIMEOUT'ed state (bit 0) - back to default.
	158	*/
84af401a AC	159	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	160	outb_p(0x08, IO_DATA_PORT);
	161	outb_p(0xF2, IO_INDEX_PORT);
	162	outb_p(0xFF, IO_DATA_PORT);
	163	outb_p(0xF3, IO_INDEX_PORT);
	164	outb_p(0x00, IO_DATA_PORT);
	165	outb_p(0xF4, IO_INDEX_PORT);
	166	outb_p(0x00, IO_DATA_PORT);
	167	outb_p(0xF2, IO_INDEX_PORT);
	168	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	169
b4cc4aa2 JMG	170	/*
84af401a	171	* Select device Aux1 (dev=7) to set GP16 (in reg E6) and
b4cc4aa2 JMG	172	* Gp13 (in reg E3) as inputs.
b4cc4aa2 JMG	173	*/
84af401a AC	174	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	175	outb_p(0x07, IO_DATA_PORT);
	176	if (!testmode) {
	177	outb_p(0xE6, IO_INDEX_PORT);
	178	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	179	}
84af401a AC	180	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	181	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	182
b4cc4aa2 JMG	183	/* Lock the SuperIO chip */
84af401a	184	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	185
	186	spin_unlock_irqrestore(&spinlock, flags);
	187
27c766aa	188	pr_info("shutdown\n");
b4cc4aa2 JMG	189
	190	return 0;
	191	}
	192
	193	/*
	194	* Send a keepalive ping to the watchdog
	195	* This is done by simply re-writing the timeout to reg. 0xF2
	196	*/
	197
	198	static int wdt_keepalive(void)
	199	{
	200	unsigned long flags;
	201
	202	spin_lock_irqsave(&spinlock, flags);
	203
	204	/* Unlock the SuperIO chip */
84af401a AC	205	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	206	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	207
b4cc4aa2 JMG	208	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
84af401a AC	209	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	210	outb_p(0x08, IO_DATA_PORT);
	211	outb_p(0xF2, IO_INDEX_PORT);
	212	outb_p(timeoutW, IO_DATA_PORT);
b4cc4aa2 JMG	213
b4cc4aa2 JMG	214	/* Lock the SuperIO chip */
84af401a	215	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	216
	217	spin_unlock_irqrestore(&spinlock, flags);
	218
	219	return 0;
	220	}
	221
	222	/*
	223	* Set the watchdog timeout value
	224	*/
	225
	226	static int wdt_set_timeout(int t)
	227	{
	228	int tmrval;
	229
	230	/*
	231	* Convert seconds to watchdog counter time units, rounding up.
84af401a	232	* On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
b4cc4aa2 JMG	233	* value. This information is supplied in the PCM-5335 manual and was
	234	* checked by me on a real board. This is a bit strange because W83977f
	235	* datasheet says counter unit is in minutes!
	236	*/
	237	if (t < 15)
	238	return -EINVAL;
	239
	240	tmrval = ((t + 15) + 29) / 30;
	241
	242	if (tmrval > 255)
	243	return -EINVAL;
	244
	245	/*
84af401a	246	* timeout is the timeout in seconds,
b4cc4aa2 JMG	247	* timeoutW is the timeout in watchdog counter units.
	248	*/
	249	timeoutW = tmrval;
	250	timeout = (timeoutW * 30) - 15;
	251	return 0;
	252	}
	253
	254	/*
	255	* Get the watchdog status
	256	*/
	257
	258	static int wdt_get_status(int *status)
	259	{
	260	int new_status;
	261	unsigned long flags;
	262
	263	spin_lock_irqsave(&spinlock, flags);
	264
	265	/* Unlock the SuperIO chip */
84af401a AC	266	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	267	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	268
b4cc4aa2 JMG	269	/* Select device Aux2 (device=8) to read watchdog reg F4 */
84af401a AC	270	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	271	outb_p(0x08, IO_DATA_PORT);
	272	outb_p(0xF4, IO_INDEX_PORT);
b4cc4aa2 JMG	273	new_status = inb_p(IO_DATA_PORT);
	274
	275	/* Lock the SuperIO chip */
84af401a	276	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	277
	278	spin_unlock_irqrestore(&spinlock, flags);
	279
	280	*status = 0;
	281	if (new_status & 1)
	282	*status \|= WDIOF_CARDRESET;
	283
	284	return 0;
	285	}
	286
	287
	288	/*
	289	* /dev/watchdog handling
	290	*/
	291
	292	static int wdt_open(struct inode inode, struct file file)
	293	{
	294	/* If the watchdog is alive we don't need to start it again */
84af401a	295	if (test_and_set_bit(0, &timer_alive))
b4cc4aa2 JMG	296	return -EBUSY;
	297
	298	if (nowayout)
	299	__module_get(THIS_MODULE);
	300
	301	wdt_start();
	302	return nonseekable_open(inode, file);
	303	}
	304
	305	static int wdt_release(struct inode inode, struct file file)
	306	{
	307	/*
	308	* Shut off the timer.
	309	* Lock it in if it's a module and we set nowayout
	310	*/
84af401a	311	if (expect_close == 42) {
b4cc4aa2 JMG	312	wdt_stop();
	313	clear_bit(0, &timer_alive);
	314	} else {
	315	wdt_keepalive();
27c766aa	316	pr_crit("unexpected close, not stopping watchdog!\n");
b4cc4aa2 JMG	317	}
	318	expect_close = 0;
	319	return 0;
	320	}
	321
	322	/*
	323	* wdt_write:
	324	* @file: file handle to the watchdog
	325	* @buf: buffer to write (unused as data does not matter here
	326	* @count: count of bytes
	327	* @ppos: pointer to the position to write. No seeks allowed
	328	*
	329	* A write to a watchdog device is defined as a keepalive signal. Any
	330	* write of data will do, as we we don't define content meaning.
	331	*/
	332
	333	static ssize_t wdt_write(struct file file, const char __user buf,
	334	size_t count, loff_t *ppos)
	335	{
	336	/* See if we got the magic character 'V' and reload the timer */
84af401a AC	337	if (count) {
84af401a AC	338	if (!nowayout) {
b4cc4aa2 JMG	339	size_t ofs;
b4cc4aa2 JMG	340
84af401a AC	341	/* note: just in case someone wrote the
84af401a AC	342	magic character long ago */
b4cc4aa2 JMG	343	expect_close = 0;
b4cc4aa2 JMG	344
84af401a AC	345	/* scan to see whether or not we got the
	346	magic character */
	347	for (ofs = 0; ofs != count; ofs++) {
b4cc4aa2 JMG	348	char c;
	349	if (get_user(c, buf + ofs))
	350	return -EFAULT;
84af401a	351	if (c == 'V')
b4cc4aa2	352	expect_close = 42;
b4cc4aa2 JMG	353	}
	354	}
	355
	356	/* someone wrote to us, we should restart timer */
	357	wdt_keepalive();
	358	}
	359	return count;
	360	}
	361
	362	/*
	363	* wdt_ioctl:
	364	* @inode: inode of the device
	365	* @file: file handle to the device
	366	* @cmd: watchdog command
	367	* @arg: argument pointer
	368	*
	369	* The watchdog API defines a common set of functions for all watchdogs
	370	* according to their available features.
	371	*/
	372
42747d71	373	static const struct watchdog_info ident = {
b4cc4aa2 JMG	374	.options = WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE \| WDIOF_KEEPALIVEPING,
	375	.firmware_version = 1,
	376	.identity = WATCHDOG_NAME,
	377	};
	378
84af401a	379	static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
b4cc4aa2 JMG	380	{
	381	int status;
	382	int new_options, retval = -EINVAL;
	383	int new_timeout;
	384	union {
	385	struct watchdog_info __user *ident;
	386	int __user *i;
	387	} uarg;
	388
	389	uarg.i = (int __user *)arg;
	390
84af401a	391	switch (cmd) {
b4cc4aa2	392	case WDIOC_GETSUPPORT:
84af401a AC	393	return copy_to_user(uarg.ident, &ident,
84af401a AC	394	sizeof(ident)) ? -EFAULT : 0;
b4cc4aa2 JMG	395
	396	case WDIOC_GETSTATUS:
	397	wdt_get_status(&status);
	398	return put_user(status, uarg.i);
	399
	400	case WDIOC_GETBOOTSTATUS:
	401	return put_user(0, uarg.i);
	402
b4cc4aa2	403	case WDIOC_SETOPTIONS:
84af401a	404	if (get_user(new_options, uarg.i))
b4cc4aa2 JMG	405	return -EFAULT;
	406
	407	if (new_options & WDIOS_DISABLECARD) {
	408	wdt_stop();
	409	retval = 0;
	410	}
	411
	412	if (new_options & WDIOS_ENABLECARD) {
	413	wdt_start();
	414	retval = 0;
	415	}
	416
	417	return retval;
	418
0c06090c WVS	419	case WDIOC_KEEPALIVE:
	420	wdt_keepalive();
	421	return 0;
	422
b4cc4aa2 JMG	423	case WDIOC_SETTIMEOUT:
	424	if (get_user(new_timeout, uarg.i))
	425	return -EFAULT;
	426
	427	if (wdt_set_timeout(new_timeout))
143a2e54	428	return -EINVAL;
b4cc4aa2 JMG	429
	430	wdt_keepalive();
	431	/* Fall */
	432
	433	case WDIOC_GETTIMEOUT:
	434	return put_user(timeout, uarg.i);
	435
0c06090c WVS	436	default:
	437	return -ENOTTY;
	438
b4cc4aa2 JMG	439	}
	440	}
	441
	442	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	443	void *unused)
	444	{
84af401a	445	if (code == SYS_DOWN \|\| code == SYS_HALT)
b4cc4aa2 JMG	446	wdt_stop();
	447	return NOTIFY_DONE;
	448	}
	449
84af401a	450	static const struct file_operations wdt_fops = {
b4cc4aa2 JMG	451	.owner = THIS_MODULE,
	452	.llseek = no_llseek,
	453	.write = wdt_write,
84af401a	454	.unlocked_ioctl = wdt_ioctl,
b4cc4aa2 JMG	455	.open = wdt_open,
	456	.release = wdt_release,
	457	};
	458
84af401a	459	static struct miscdevice wdt_miscdev = {
b4cc4aa2 JMG	460	.minor = WATCHDOG_MINOR,
	461	.name = "watchdog",
	462	.fops = &wdt_fops,
	463	};
	464
	465	static struct notifier_block wdt_notifier = {
	466	.notifier_call = wdt_notify_sys,
	467	};
	468
	469	static int __init w83977f_wdt_init(void)
	470	{
	471	int rc;
	472
27c766aa	473	pr_info("driver v%s\n", WATCHDOG_VERSION);
b4cc4aa2	474
b4cc4aa2	475	/*
84af401a	476	* Check that the timeout value is within it's range;
b4cc4aa2 JMG	477	* if not reset to the default
	478	*/
	479	if (wdt_set_timeout(timeout)) {
	480	wdt_set_timeout(DEFAULT_TIMEOUT);
27c766aa JP	481	pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n",
27c766aa JP	482	DEFAULT_TIMEOUT);
b4cc4aa2 JMG	483	}
b4cc4aa2 JMG	484
84af401a	485	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
27c766aa	486	pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT);
b4cc4aa2 JMG	487	rc = -EIO;
	488	goto err_out;
	489	}
	490
c6cb13ae	491	rc = register_reboot_notifier(&wdt_notifier);
84af401a	492	if (rc) {
27c766aa	493	pr_err("cannot register reboot notifier (err=%d)\n", rc);
b4cc4aa2 JMG	494	goto err_out_region;
	495	}
	496
c6cb13ae	497	rc = misc_register(&wdt_miscdev);
84af401a	498	if (rc) {
27c766aa JP	499	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	500	wdt_miscdev.minor, rc);
c6cb13ae	501	goto err_out_reboot;
b4cc4aa2 JMG	502	}
b4cc4aa2 JMG	503
27c766aa JP	504	pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
27c766aa JP	505	timeout, nowayout, testmode);
b4cc4aa2 JMG	506
	507	return 0;
	508
c6cb13ae WVS	509	err_out_reboot:
c6cb13ae WVS	510	unregister_reboot_notifier(&wdt_notifier);
b4cc4aa2	511	err_out_region:
84af401a	512	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	513	err_out:
	514	return rc;
	515	}
	516
	517	static void __exit w83977f_wdt_exit(void)
	518	{
	519	wdt_stop();
	520	misc_deregister(&wdt_miscdev);
	521	unregister_reboot_notifier(&wdt_notifier);
84af401a	522	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	523	}
	524
	525	module_init(w83977f_wdt_init);
	526	module_exit(w83977f_wdt_exit);
	527
	528	MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
	529	MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
	530	MODULE_LICENSE("GPL");
	531	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);