[GitHub/mt8127/android_kernel_alcatel_ttab.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>


#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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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 JMG	34
	35	#define WATCHDOG_VERSION "1.00"
	36	#define WATCHDOG_NAME "W83977F WDT"
b4cc4aa2 JMG	37
	38	#define IO_INDEX_PORT 0x3F0
	39	#define IO_DATA_PORT (IO_INDEX_PORT+1)
	40
	41	#define UNLOCK_DATA 0x87
	42	#define LOCK_DATA 0xAA
	43	#define DEVICE_REGISTER 0x07
	44
	45	#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
	46
	47	static int timeout = DEFAULT_TIMEOUT;
	48	static int timeoutW; /* timeout in watchdog counter units */
	49	static unsigned long timer_alive;
	50	static int testmode;
	51	static char expect_close;
c7dfd0cc	52	static DEFINE_SPINLOCK(spinlock);
b4cc4aa2 JMG	53
b4cc4aa2 JMG	54	module_param(timeout, int, 0);
84af401a AC	55	MODULE_PARM_DESC(timeout,
	56	"Watchdog timeout in seconds (15..7635), default="
	57	__MODULE_STRING(DEFAULT_TIMEOUT) ")");
b4cc4aa2	58	module_param(testmode, int, 0);
84af401a	59	MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
b4cc4aa2	60
86a1e189 WVS	61	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	62	module_param(nowayout, bool, 0);
84af401a AC	63	MODULE_PARM_DESC(nowayout,
	64	"Watchdog cannot be stopped once started (default="
	65	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b4cc4aa2 JMG	66
	67	/*
	68	* Start the watchdog
	69	*/
	70
	71	static int wdt_start(void)
	72	{
	73	unsigned long flags;
	74
	75	spin_lock_irqsave(&spinlock, flags);
	76
	77	/* Unlock the SuperIO chip */
84af401a AC	78	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	79	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	80
	81	/*
	82	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	83	* F2 has the timeout in watchdog counter units.
	84	* F3 is set to enable watchdog LED blink at timeout.
	85	* F4 is used to just clear the TIMEOUT'ed state (bit 0).
	86	*/
84af401a AC	87	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	88	outb_p(0x08, IO_DATA_PORT);
	89	outb_p(0xF2, IO_INDEX_PORT);
	90	outb_p(timeoutW, IO_DATA_PORT);
	91	outb_p(0xF3, IO_INDEX_PORT);
	92	outb_p(0x08, IO_DATA_PORT);
	93	outb_p(0xF4, IO_INDEX_PORT);
	94	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	95
b4cc4aa2 JMG	96	/* Set device Aux2 active */
84af401a AC	97	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	98	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	99
84af401a	100	/*
b4cc4aa2 JMG	101	* Select device Aux1 (dev=7) to set GP16 as the watchdog output
	102	* (in reg E6) and GP13 as the watchdog LED output (in reg E3).
	103	* Map GP16 at pin 119.
	104	* In test mode watch the bit 0 on F4 to indicate "triggered" or
	105	* check watchdog LED on SBC.
	106	*/
84af401a AC	107	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	108	outb_p(0x07, IO_DATA_PORT);
	109	if (!testmode) {
b4cc4aa2 JMG	110	unsigned pin_map;
b4cc4aa2 JMG	111
84af401a AC	112	outb_p(0xE6, IO_INDEX_PORT);
	113	outb_p(0x0A, IO_DATA_PORT);
	114	outb_p(0x2C, IO_INDEX_PORT);
b4cc4aa2 JMG	115	pin_map = inb_p(IO_DATA_PORT);
	116	pin_map \|= 0x10;
	117	pin_map &= ~(0x20);
84af401a AC	118	outb_p(0x2C, IO_INDEX_PORT);
84af401a AC	119	outb_p(pin_map, IO_DATA_PORT);
b4cc4aa2	120	}
84af401a AC	121	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	122	outb_p(0x08, IO_DATA_PORT);
b4cc4aa2 JMG	123
b4cc4aa2 JMG	124	/* Set device Aux1 active */
84af401a AC	125	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	126	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	127
b4cc4aa2 JMG	128	/* Lock the SuperIO chip */
84af401a	129	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	130
	131	spin_unlock_irqrestore(&spinlock, flags);
	132
27c766aa	133	pr_info("activated\n");
b4cc4aa2 JMG	134
	135	return 0;
	136	}
	137
	138	/*
	139	* Stop the watchdog
	140	*/
	141
	142	static int wdt_stop(void)
	143	{
	144	unsigned long flags;
	145
	146	spin_lock_irqsave(&spinlock, flags);
	147
	148	/* Unlock the SuperIO chip */
84af401a AC	149	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	150	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2	151
84af401a	152	/*
b4cc4aa2 JMG	153	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	154	* F2 is reset to its default value (watchdog timer disabled).
	155	* F3 is reset to its default state.
	156	* F4 clears the TIMEOUT'ed state (bit 0) - back to default.
	157	*/
84af401a AC	158	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	159	outb_p(0x08, IO_DATA_PORT);
	160	outb_p(0xF2, IO_INDEX_PORT);
	161	outb_p(0xFF, IO_DATA_PORT);
	162	outb_p(0xF3, IO_INDEX_PORT);
	163	outb_p(0x00, IO_DATA_PORT);
	164	outb_p(0xF4, IO_INDEX_PORT);
	165	outb_p(0x00, IO_DATA_PORT);
	166	outb_p(0xF2, IO_INDEX_PORT);
	167	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	168
b4cc4aa2 JMG	169	/*
84af401a	170	* Select device Aux1 (dev=7) to set GP16 (in reg E6) and
b4cc4aa2 JMG	171	* Gp13 (in reg E3) as inputs.
b4cc4aa2 JMG	172	*/
84af401a AC	173	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	174	outb_p(0x07, IO_DATA_PORT);
	175	if (!testmode) {
	176	outb_p(0xE6, IO_INDEX_PORT);
	177	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	178	}
84af401a AC	179	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	180	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	181
b4cc4aa2 JMG	182	/* Lock the SuperIO chip */
84af401a	183	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	184
	185	spin_unlock_irqrestore(&spinlock, flags);
	186
27c766aa	187	pr_info("shutdown\n");
b4cc4aa2 JMG	188
	189	return 0;
	190	}
	191
	192	/*
	193	* Send a keepalive ping to the watchdog
	194	* This is done by simply re-writing the timeout to reg. 0xF2
	195	*/
	196
	197	static int wdt_keepalive(void)
	198	{
	199	unsigned long flags;
	200
	201	spin_lock_irqsave(&spinlock, flags);
	202
	203	/* Unlock the SuperIO chip */
84af401a AC	204	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	205	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	206
b4cc4aa2 JMG	207	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
84af401a AC	208	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	209	outb_p(0x08, IO_DATA_PORT);
	210	outb_p(0xF2, IO_INDEX_PORT);
	211	outb_p(timeoutW, IO_DATA_PORT);
b4cc4aa2 JMG	212
b4cc4aa2 JMG	213	/* Lock the SuperIO chip */
84af401a	214	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	215
	216	spin_unlock_irqrestore(&spinlock, flags);
	217
	218	return 0;
	219	}
	220
	221	/*
	222	* Set the watchdog timeout value
	223	*/
	224
	225	static int wdt_set_timeout(int t)
	226	{
	227	int tmrval;
	228
	229	/*
	230	* Convert seconds to watchdog counter time units, rounding up.
84af401a	231	* On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
b4cc4aa2 JMG	232	* value. This information is supplied in the PCM-5335 manual and was
	233	* checked by me on a real board. This is a bit strange because W83977f
	234	* datasheet says counter unit is in minutes!
	235	*/
	236	if (t < 15)
	237	return -EINVAL;
	238
	239	tmrval = ((t + 15) + 29) / 30;
	240
	241	if (tmrval > 255)
	242	return -EINVAL;
	243
	244	/*
84af401a	245	* timeout is the timeout in seconds,
b4cc4aa2 JMG	246	* timeoutW is the timeout in watchdog counter units.
	247	*/
	248	timeoutW = tmrval;
	249	timeout = (timeoutW * 30) - 15;
	250	return 0;
	251	}
	252
	253	/*
	254	* Get the watchdog status
	255	*/
	256
	257	static int wdt_get_status(int *status)
	258	{
	259	int new_status;
	260	unsigned long flags;
	261
	262	spin_lock_irqsave(&spinlock, flags);
	263
	264	/* Unlock the SuperIO chip */
84af401a AC	265	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	266	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	267
b4cc4aa2 JMG	268	/* Select device Aux2 (device=8) to read watchdog reg F4 */
84af401a AC	269	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	270	outb_p(0x08, IO_DATA_PORT);
	271	outb_p(0xF4, IO_INDEX_PORT);
b4cc4aa2 JMG	272	new_status = inb_p(IO_DATA_PORT);
	273
	274	/* Lock the SuperIO chip */
84af401a	275	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	276
	277	spin_unlock_irqrestore(&spinlock, flags);
	278
	279	*status = 0;
	280	if (new_status & 1)
	281	*status \|= WDIOF_CARDRESET;
	282
	283	return 0;
	284	}
	285
	286
	287	/*
	288	* /dev/watchdog handling
	289	*/
	290
	291	static int wdt_open(struct inode inode, struct file file)
	292	{
	293	/* If the watchdog is alive we don't need to start it again */
84af401a	294	if (test_and_set_bit(0, &timer_alive))
b4cc4aa2 JMG	295	return -EBUSY;
	296
	297	if (nowayout)
	298	__module_get(THIS_MODULE);
	299
	300	wdt_start();
	301	return nonseekable_open(inode, file);
	302	}
	303
	304	static int wdt_release(struct inode inode, struct file file)
	305	{
	306	/*
	307	* Shut off the timer.
	308	* Lock it in if it's a module and we set nowayout
	309	*/
84af401a	310	if (expect_close == 42) {
b4cc4aa2 JMG	311	wdt_stop();
	312	clear_bit(0, &timer_alive);
	313	} else {
	314	wdt_keepalive();
27c766aa	315	pr_crit("unexpected close, not stopping watchdog!\n");
b4cc4aa2 JMG	316	}
	317	expect_close = 0;
	318	return 0;
	319	}
	320
	321	/*
	322	* wdt_write:
	323	* @file: file handle to the watchdog
	324	* @buf: buffer to write (unused as data does not matter here
	325	* @count: count of bytes
	326	* @ppos: pointer to the position to write. No seeks allowed
	327	*
	328	* A write to a watchdog device is defined as a keepalive signal. Any
	329	* write of data will do, as we we don't define content meaning.
	330	*/
	331
	332	static ssize_t wdt_write(struct file file, const char __user buf,
	333	size_t count, loff_t *ppos)
	334	{
	335	/* See if we got the magic character 'V' and reload the timer */
84af401a AC	336	if (count) {
84af401a AC	337	if (!nowayout) {
b4cc4aa2 JMG	338	size_t ofs;
b4cc4aa2 JMG	339
84af401a AC	340	/* note: just in case someone wrote the
84af401a AC	341	magic character long ago */
b4cc4aa2 JMG	342	expect_close = 0;
b4cc4aa2 JMG	343
84af401a AC	344	/* scan to see whether or not we got the
	345	magic character */
	346	for (ofs = 0; ofs != count; ofs++) {
b4cc4aa2 JMG	347	char c;
	348	if (get_user(c, buf + ofs))
	349	return -EFAULT;
84af401a	350	if (c == 'V')
b4cc4aa2	351	expect_close = 42;
b4cc4aa2 JMG	352	}
	353	}
	354
	355	/* someone wrote to us, we should restart timer */
	356	wdt_keepalive();
	357	}
	358	return count;
	359	}
	360
	361	/*
	362	* wdt_ioctl:
	363	* @inode: inode of the device
	364	* @file: file handle to the device
	365	* @cmd: watchdog command
	366	* @arg: argument pointer
	367	*
	368	* The watchdog API defines a common set of functions for all watchdogs
	369	* according to their available features.
	370	*/
	371
42747d71	372	static const struct watchdog_info ident = {
b4cc4aa2 JMG	373	.options = WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE \| WDIOF_KEEPALIVEPING,
	374	.firmware_version = 1,
	375	.identity = WATCHDOG_NAME,
	376	};
	377
84af401a	378	static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
b4cc4aa2 JMG	379	{
	380	int status;
	381	int new_options, retval = -EINVAL;
	382	int new_timeout;
	383	union {
	384	struct watchdog_info __user *ident;
	385	int __user *i;
	386	} uarg;
	387
	388	uarg.i = (int __user *)arg;
	389
84af401a	390	switch (cmd) {
b4cc4aa2	391	case WDIOC_GETSUPPORT:
84af401a AC	392	return copy_to_user(uarg.ident, &ident,
84af401a AC	393	sizeof(ident)) ? -EFAULT : 0;
b4cc4aa2 JMG	394
	395	case WDIOC_GETSTATUS:
	396	wdt_get_status(&status);
	397	return put_user(status, uarg.i);
	398
	399	case WDIOC_GETBOOTSTATUS:
	400	return put_user(0, uarg.i);
	401
b4cc4aa2	402	case WDIOC_SETOPTIONS:
84af401a	403	if (get_user(new_options, uarg.i))
b4cc4aa2 JMG	404	return -EFAULT;
	405
	406	if (new_options & WDIOS_DISABLECARD) {
	407	wdt_stop();
	408	retval = 0;
	409	}
	410
	411	if (new_options & WDIOS_ENABLECARD) {
	412	wdt_start();
	413	retval = 0;
	414	}
	415
	416	return retval;
	417
0c06090c WVS	418	case WDIOC_KEEPALIVE:
	419	wdt_keepalive();
	420	return 0;
	421
b4cc4aa2 JMG	422	case WDIOC_SETTIMEOUT:
	423	if (get_user(new_timeout, uarg.i))
	424	return -EFAULT;
	425
	426	if (wdt_set_timeout(new_timeout))
143a2e54	427	return -EINVAL;
b4cc4aa2 JMG	428
	429	wdt_keepalive();
	430	/* Fall */
	431
	432	case WDIOC_GETTIMEOUT:
	433	return put_user(timeout, uarg.i);
	434
0c06090c WVS	435	default:
	436	return -ENOTTY;
	437
b4cc4aa2 JMG	438	}
	439	}
	440
	441	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	442	void *unused)
	443	{
84af401a	444	if (code == SYS_DOWN \|\| code == SYS_HALT)
b4cc4aa2 JMG	445	wdt_stop();
	446	return NOTIFY_DONE;
	447	}
	448
84af401a	449	static const struct file_operations wdt_fops = {
b4cc4aa2 JMG	450	.owner = THIS_MODULE,
	451	.llseek = no_llseek,
	452	.write = wdt_write,
84af401a	453	.unlocked_ioctl = wdt_ioctl,
b4cc4aa2 JMG	454	.open = wdt_open,
	455	.release = wdt_release,
	456	};
	457
84af401a	458	static struct miscdevice wdt_miscdev = {
b4cc4aa2 JMG	459	.minor = WATCHDOG_MINOR,
	460	.name = "watchdog",
	461	.fops = &wdt_fops,
	462	};
	463
	464	static struct notifier_block wdt_notifier = {
	465	.notifier_call = wdt_notify_sys,
	466	};
	467
	468	static int __init w83977f_wdt_init(void)
	469	{
	470	int rc;
	471
27c766aa	472	pr_info("driver v%s\n", WATCHDOG_VERSION);
b4cc4aa2	473
b4cc4aa2	474	/*
84af401a	475	* Check that the timeout value is within it's range;
b4cc4aa2 JMG	476	* if not reset to the default
	477	*/
	478	if (wdt_set_timeout(timeout)) {
	479	wdt_set_timeout(DEFAULT_TIMEOUT);
27c766aa JP	480	pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n",
27c766aa JP	481	DEFAULT_TIMEOUT);
b4cc4aa2 JMG	482	}
b4cc4aa2 JMG	483
84af401a	484	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
27c766aa	485	pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT);
b4cc4aa2 JMG	486	rc = -EIO;
	487	goto err_out;
	488	}
	489
c6cb13ae	490	rc = register_reboot_notifier(&wdt_notifier);
84af401a	491	if (rc) {
27c766aa	492	pr_err("cannot register reboot notifier (err=%d)\n", rc);
b4cc4aa2 JMG	493	goto err_out_region;
	494	}
	495
c6cb13ae	496	rc = misc_register(&wdt_miscdev);
84af401a	497	if (rc) {
27c766aa JP	498	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	499	wdt_miscdev.minor, rc);
c6cb13ae	500	goto err_out_reboot;
b4cc4aa2 JMG	501	}
b4cc4aa2 JMG	502
27c766aa JP	503	pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
27c766aa JP	504	timeout, nowayout, testmode);
b4cc4aa2 JMG	505
	506	return 0;
	507
c6cb13ae WVS	508	err_out_reboot:
c6cb13ae WVS	509	unregister_reboot_notifier(&wdt_notifier);
b4cc4aa2	510	err_out_region:
84af401a	511	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	512	err_out:
	513	return rc;
	514	}
	515
	516	static void __exit w83977f_wdt_exit(void)
	517	{
	518	wdt_stop();
	519	misc_deregister(&wdt_miscdev);
	520	unregister_reboot_notifier(&wdt_notifier);
84af401a	521	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	522	}
	523
	524	module_init(w83977f_wdt_init);
	525	module_exit(w83977f_wdt_exit);
	526
	527	MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
	528	MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
	529	MODULE_LICENSE("GPL");
	530	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);