[linux-2.6-block.git] / drivers / watchdog / w83977f_wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	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
 *
 *			-----------------------
 */

#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)
{
	unsigned 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 stream_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 through */

	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");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
b4cc4aa2 JMG	2	/*
	3	* W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
	4	*
	5	* (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
	6	*
	7	* Based on w83877f_wdt.c by Scott Jennings,
	8	* and wdt977.c by Woody Suwalski
	9	*
	10	* -----------------------
b4cc4aa2 JMG	11	*/
b4cc4aa2 JMG	12
27c766aa JP	13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	14
b4cc4aa2 JMG	15	#include <linux/module.h>
b4cc4aa2 JMG	16	#include <linux/moduleparam.h>
b4cc4aa2 JMG	17	#include <linux/types.h>
	18	#include <linux/kernel.h>
	19	#include <linux/fs.h>
	20	#include <linux/miscdevice.h>
	21	#include <linux/init.h>
	22	#include <linux/ioport.h>
	23	#include <linux/watchdog.h>
	24	#include <linux/notifier.h>
	25	#include <linux/reboot.h>
84af401a AC	26	#include <linux/uaccess.h>
84af401a AC	27	#include <linux/io.h>
b4cc4aa2	28
b4cc4aa2 JMG	29
	30	#define WATCHDOG_VERSION "1.00"
	31	#define WATCHDOG_NAME "W83977F WDT"
b4cc4aa2 JMG	32
	33	#define IO_INDEX_PORT 0x3F0
	34	#define IO_DATA_PORT (IO_INDEX_PORT+1)
	35
	36	#define UNLOCK_DATA 0x87
	37	#define LOCK_DATA 0xAA
	38	#define DEVICE_REGISTER 0x07
	39
	40	#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
	41
	42	static int timeout = DEFAULT_TIMEOUT;
	43	static int timeoutW; /* timeout in watchdog counter units */
	44	static unsigned long timer_alive;
	45	static int testmode;
	46	static char expect_close;
c7dfd0cc	47	static DEFINE_SPINLOCK(spinlock);
b4cc4aa2 JMG	48
b4cc4aa2 JMG	49	module_param(timeout, int, 0);
84af401a AC	50	MODULE_PARM_DESC(timeout,
	51	"Watchdog timeout in seconds (15..7635), default="
	52	__MODULE_STRING(DEFAULT_TIMEOUT) ")");
b4cc4aa2	53	module_param(testmode, int, 0);
84af401a	54	MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
b4cc4aa2	55
86a1e189 WVS	56	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	57	module_param(nowayout, bool, 0);
84af401a AC	58	MODULE_PARM_DESC(nowayout,
	59	"Watchdog cannot be stopped once started (default="
	60	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b4cc4aa2 JMG	61
	62	/*
	63	* Start the watchdog
	64	*/
	65
	66	static int wdt_start(void)
	67	{
	68	unsigned long flags;
	69
	70	spin_lock_irqsave(&spinlock, flags);
	71
	72	/* Unlock the SuperIO chip */
84af401a AC	73	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	74	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	75
	76	/*
	77	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	78	* F2 has the timeout in watchdog counter units.
	79	* F3 is set to enable watchdog LED blink at timeout.
	80	* F4 is used to just clear the TIMEOUT'ed state (bit 0).
	81	*/
84af401a AC	82	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	83	outb_p(0x08, IO_DATA_PORT);
	84	outb_p(0xF2, IO_INDEX_PORT);
	85	outb_p(timeoutW, IO_DATA_PORT);
	86	outb_p(0xF3, IO_INDEX_PORT);
	87	outb_p(0x08, IO_DATA_PORT);
	88	outb_p(0xF4, IO_INDEX_PORT);
	89	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	90
b4cc4aa2 JMG	91	/* Set device Aux2 active */
84af401a AC	92	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	93	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	94
84af401a	95	/*
b4cc4aa2 JMG	96	* Select device Aux1 (dev=7) to set GP16 as the watchdog output
	97	* (in reg E6) and GP13 as the watchdog LED output (in reg E3).
	98	* Map GP16 at pin 119.
	99	* In test mode watch the bit 0 on F4 to indicate "triggered" or
	100	* check watchdog LED on SBC.
	101	*/
84af401a AC	102	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	103	outb_p(0x07, IO_DATA_PORT);
	104	if (!testmode) {
b4cc4aa2 JMG	105	unsigned pin_map;
b4cc4aa2 JMG	106
84af401a AC	107	outb_p(0xE6, IO_INDEX_PORT);
	108	outb_p(0x0A, IO_DATA_PORT);
	109	outb_p(0x2C, IO_INDEX_PORT);
b4cc4aa2 JMG	110	pin_map = inb_p(IO_DATA_PORT);
	111	pin_map \|= 0x10;
	112	pin_map &= ~(0x20);
84af401a AC	113	outb_p(0x2C, IO_INDEX_PORT);
84af401a AC	114	outb_p(pin_map, IO_DATA_PORT);
b4cc4aa2	115	}
84af401a AC	116	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	117	outb_p(0x08, IO_DATA_PORT);
b4cc4aa2 JMG	118
b4cc4aa2 JMG	119	/* Set device Aux1 active */
84af401a AC	120	outb_p(0x30, IO_INDEX_PORT);
84af401a AC	121	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	122
b4cc4aa2 JMG	123	/* Lock the SuperIO chip */
84af401a	124	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	125
	126	spin_unlock_irqrestore(&spinlock, flags);
	127
27c766aa	128	pr_info("activated\n");
b4cc4aa2 JMG	129
	130	return 0;
	131	}
	132
	133	/*
	134	* Stop the watchdog
	135	*/
	136
	137	static int wdt_stop(void)
	138	{
	139	unsigned long flags;
	140
	141	spin_lock_irqsave(&spinlock, flags);
	142
	143	/* Unlock the SuperIO chip */
84af401a AC	144	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	145	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2	146
84af401a	147	/*
b4cc4aa2 JMG	148	* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	149	* F2 is reset to its default value (watchdog timer disabled).
	150	* F3 is reset to its default state.
	151	* F4 clears the TIMEOUT'ed state (bit 0) - back to default.
	152	*/
84af401a AC	153	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	154	outb_p(0x08, IO_DATA_PORT);
	155	outb_p(0xF2, IO_INDEX_PORT);
	156	outb_p(0xFF, IO_DATA_PORT);
	157	outb_p(0xF3, IO_INDEX_PORT);
	158	outb_p(0x00, IO_DATA_PORT);
	159	outb_p(0xF4, IO_INDEX_PORT);
	160	outb_p(0x00, IO_DATA_PORT);
	161	outb_p(0xF2, IO_INDEX_PORT);
	162	outb_p(0x00, IO_DATA_PORT);
b4cc4aa2 JMG	163
b4cc4aa2 JMG	164	/*
84af401a	165	* Select device Aux1 (dev=7) to set GP16 (in reg E6) and
b4cc4aa2 JMG	166	* Gp13 (in reg E3) as inputs.
b4cc4aa2 JMG	167	*/
84af401a AC	168	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	169	outb_p(0x07, IO_DATA_PORT);
	170	if (!testmode) {
	171	outb_p(0xE6, IO_INDEX_PORT);
	172	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2	173	}
84af401a AC	174	outb_p(0xE3, IO_INDEX_PORT);
84af401a AC	175	outb_p(0x01, IO_DATA_PORT);
b4cc4aa2 JMG	176
b4cc4aa2 JMG	177	/* Lock the SuperIO chip */
84af401a	178	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	179
	180	spin_unlock_irqrestore(&spinlock, flags);
	181
27c766aa	182	pr_info("shutdown\n");
b4cc4aa2 JMG	183
	184	return 0;
	185	}
	186
	187	/*
	188	* Send a keepalive ping to the watchdog
	189	* This is done by simply re-writing the timeout to reg. 0xF2
	190	*/
	191
	192	static int wdt_keepalive(void)
	193	{
	194	unsigned long flags;
	195
	196	spin_lock_irqsave(&spinlock, flags);
	197
	198	/* Unlock the SuperIO chip */
84af401a AC	199	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	200	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	201
b4cc4aa2 JMG	202	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
84af401a AC	203	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	204	outb_p(0x08, IO_DATA_PORT);
	205	outb_p(0xF2, IO_INDEX_PORT);
	206	outb_p(timeoutW, IO_DATA_PORT);
b4cc4aa2 JMG	207
b4cc4aa2 JMG	208	/* Lock the SuperIO chip */
84af401a	209	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	210
	211	spin_unlock_irqrestore(&spinlock, flags);
	212
	213	return 0;
	214	}
	215
	216	/*
	217	* Set the watchdog timeout value
	218	*/
	219
	220	static int wdt_set_timeout(int t)
	221	{
62ed853c	222	unsigned int tmrval;
b4cc4aa2 JMG	223
	224	/*
	225	* Convert seconds to watchdog counter time units, rounding up.
84af401a	226	* On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
b4cc4aa2 JMG	227	* value. This information is supplied in the PCM-5335 manual and was
	228	* checked by me on a real board. This is a bit strange because W83977f
	229	* datasheet says counter unit is in minutes!
	230	*/
	231	if (t < 15)
	232	return -EINVAL;
	233
	234	tmrval = ((t + 15) + 29) / 30;
	235
	236	if (tmrval > 255)
	237	return -EINVAL;
	238
	239	/*
84af401a	240	* timeout is the timeout in seconds,
b4cc4aa2 JMG	241	* timeoutW is the timeout in watchdog counter units.
	242	*/
	243	timeoutW = tmrval;
	244	timeout = (timeoutW * 30) - 15;
	245	return 0;
	246	}
	247
	248	/*
	249	* Get the watchdog status
	250	*/
	251
	252	static int wdt_get_status(int *status)
	253	{
	254	int new_status;
	255	unsigned long flags;
	256
	257	spin_lock_irqsave(&spinlock, flags);
	258
	259	/* Unlock the SuperIO chip */
84af401a AC	260	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
84af401a AC	261	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	262
b4cc4aa2 JMG	263	/* Select device Aux2 (device=8) to read watchdog reg F4 */
84af401a AC	264	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	265	outb_p(0x08, IO_DATA_PORT);
	266	outb_p(0xF4, IO_INDEX_PORT);
b4cc4aa2 JMG	267	new_status = inb_p(IO_DATA_PORT);
	268
	269	/* Lock the SuperIO chip */
84af401a	270	outb_p(LOCK_DATA, IO_INDEX_PORT);
b4cc4aa2 JMG	271
	272	spin_unlock_irqrestore(&spinlock, flags);
	273
	274	*status = 0;
	275	if (new_status & 1)
	276	*status \|= WDIOF_CARDRESET;
	277
	278	return 0;
	279	}
	280
	281
	282	/*
	283	* /dev/watchdog handling
	284	*/
	285
	286	static int wdt_open(struct inode inode, struct file file)
	287	{
	288	/* If the watchdog is alive we don't need to start it again */
84af401a	289	if (test_and_set_bit(0, &timer_alive))
b4cc4aa2 JMG	290	return -EBUSY;
	291
	292	if (nowayout)
	293	__module_get(THIS_MODULE);
	294
	295	wdt_start();
c5bf68fe	296	return stream_open(inode, file);
b4cc4aa2 JMG	297	}
	298
	299	static int wdt_release(struct inode inode, struct file file)
	300	{
	301	/*
	302	* Shut off the timer.
	303	* Lock it in if it's a module and we set nowayout
	304	*/
84af401a	305	if (expect_close == 42) {
b4cc4aa2 JMG	306	wdt_stop();
	307	clear_bit(0, &timer_alive);
	308	} else {
	309	wdt_keepalive();
27c766aa	310	pr_crit("unexpected close, not stopping watchdog!\n");
b4cc4aa2 JMG	311	}
	312	expect_close = 0;
	313	return 0;
	314	}
	315
	316	/*
	317	* wdt_write:
	318	* @file: file handle to the watchdog
	319	* @buf: buffer to write (unused as data does not matter here
	320	* @count: count of bytes
	321	* @ppos: pointer to the position to write. No seeks allowed
	322	*
	323	* A write to a watchdog device is defined as a keepalive signal. Any
	324	* write of data will do, as we we don't define content meaning.
	325	*/
	326
	327	static ssize_t wdt_write(struct file file, const char __user buf,
	328	size_t count, loff_t *ppos)
	329	{
	330	/* See if we got the magic character 'V' and reload the timer */
84af401a AC	331	if (count) {
84af401a AC	332	if (!nowayout) {
b4cc4aa2 JMG	333	size_t ofs;
b4cc4aa2 JMG	334
84af401a AC	335	/* note: just in case someone wrote the
84af401a AC	336	magic character long ago */
b4cc4aa2 JMG	337	expect_close = 0;
b4cc4aa2 JMG	338
84af401a AC	339	/* scan to see whether or not we got the
	340	magic character */
	341	for (ofs = 0; ofs != count; ofs++) {
b4cc4aa2 JMG	342	char c;
	343	if (get_user(c, buf + ofs))
	344	return -EFAULT;
84af401a	345	if (c == 'V')
b4cc4aa2	346	expect_close = 42;
b4cc4aa2 JMG	347	}
	348	}
	349
	350	/* someone wrote to us, we should restart timer */
	351	wdt_keepalive();
	352	}
	353	return count;
	354	}
	355
	356	/*
	357	* wdt_ioctl:
	358	* @inode: inode of the device
	359	* @file: file handle to the device
	360	* @cmd: watchdog command
	361	* @arg: argument pointer
	362	*
	363	* The watchdog API defines a common set of functions for all watchdogs
	364	* according to their available features.
	365	*/
	366
42747d71	367	static const struct watchdog_info ident = {
b4cc4aa2 JMG	368	.options = WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE \| WDIOF_KEEPALIVEPING,
	369	.firmware_version = 1,
	370	.identity = WATCHDOG_NAME,
	371	};
	372
84af401a	373	static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
b4cc4aa2 JMG	374	{
	375	int status;
	376	int new_options, retval = -EINVAL;
	377	int new_timeout;
	378	union {
	379	struct watchdog_info __user *ident;
	380	int __user *i;
	381	} uarg;
	382
	383	uarg.i = (int __user *)arg;
	384
84af401a	385	switch (cmd) {
b4cc4aa2	386	case WDIOC_GETSUPPORT:
84af401a AC	387	return copy_to_user(uarg.ident, &ident,
84af401a AC	388	sizeof(ident)) ? -EFAULT : 0;
b4cc4aa2 JMG	389
	390	case WDIOC_GETSTATUS:
	391	wdt_get_status(&status);
	392	return put_user(status, uarg.i);
	393
	394	case WDIOC_GETBOOTSTATUS:
	395	return put_user(0, uarg.i);
	396
b4cc4aa2	397	case WDIOC_SETOPTIONS:
84af401a	398	if (get_user(new_options, uarg.i))
b4cc4aa2 JMG	399	return -EFAULT;
	400
	401	if (new_options & WDIOS_DISABLECARD) {
	402	wdt_stop();
	403	retval = 0;
	404	}
	405
	406	if (new_options & WDIOS_ENABLECARD) {
	407	wdt_start();
	408	retval = 0;
	409	}
	410
	411	return retval;
	412
0c06090c WVS	413	case WDIOC_KEEPALIVE:
	414	wdt_keepalive();
	415	return 0;
	416
b4cc4aa2 JMG	417	case WDIOC_SETTIMEOUT:
	418	if (get_user(new_timeout, uarg.i))
	419	return -EFAULT;
	420
	421	if (wdt_set_timeout(new_timeout))
143a2e54	422	return -EINVAL;
b4cc4aa2 JMG	423
b4cc4aa2 JMG	424	wdt_keepalive();
3ff0751f	425	/* Fall through */
b4cc4aa2 JMG	426
	427	case WDIOC_GETTIMEOUT:
	428	return put_user(timeout, uarg.i);
	429
0c06090c WVS	430	default:
	431	return -ENOTTY;
	432
b4cc4aa2 JMG	433	}
	434	}
	435
	436	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	437	void *unused)
	438	{
84af401a	439	if (code == SYS_DOWN \|\| code == SYS_HALT)
b4cc4aa2 JMG	440	wdt_stop();
	441	return NOTIFY_DONE;
	442	}
	443
84af401a	444	static const struct file_operations wdt_fops = {
b4cc4aa2 JMG	445	.owner = THIS_MODULE,
	446	.llseek = no_llseek,
	447	.write = wdt_write,
84af401a	448	.unlocked_ioctl = wdt_ioctl,
b4cc4aa2 JMG	449	.open = wdt_open,
	450	.release = wdt_release,
	451	};
	452
84af401a	453	static struct miscdevice wdt_miscdev = {
b4cc4aa2 JMG	454	.minor = WATCHDOG_MINOR,
	455	.name = "watchdog",
	456	.fops = &wdt_fops,
	457	};
	458
	459	static struct notifier_block wdt_notifier = {
	460	.notifier_call = wdt_notify_sys,
	461	};
	462
	463	static int __init w83977f_wdt_init(void)
	464	{
	465	int rc;
	466
27c766aa	467	pr_info("driver v%s\n", WATCHDOG_VERSION);
b4cc4aa2	468
b4cc4aa2	469	/*
84af401a	470	* Check that the timeout value is within it's range;
b4cc4aa2 JMG	471	* if not reset to the default
	472	*/
	473	if (wdt_set_timeout(timeout)) {
	474	wdt_set_timeout(DEFAULT_TIMEOUT);
27c766aa JP	475	pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n",
27c766aa JP	476	DEFAULT_TIMEOUT);
b4cc4aa2 JMG	477	}
b4cc4aa2 JMG	478
84af401a	479	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
27c766aa	480	pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT);
b4cc4aa2 JMG	481	rc = -EIO;
	482	goto err_out;
	483	}
	484
c6cb13ae	485	rc = register_reboot_notifier(&wdt_notifier);
84af401a	486	if (rc) {
27c766aa	487	pr_err("cannot register reboot notifier (err=%d)\n", rc);
b4cc4aa2 JMG	488	goto err_out_region;
	489	}
	490
c6cb13ae	491	rc = misc_register(&wdt_miscdev);
84af401a	492	if (rc) {
27c766aa JP	493	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	494	wdt_miscdev.minor, rc);
c6cb13ae	495	goto err_out_reboot;
b4cc4aa2 JMG	496	}
b4cc4aa2 JMG	497
27c766aa JP	498	pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
27c766aa JP	499	timeout, nowayout, testmode);
b4cc4aa2 JMG	500
	501	return 0;
	502
c6cb13ae WVS	503	err_out_reboot:
c6cb13ae WVS	504	unregister_reboot_notifier(&wdt_notifier);
b4cc4aa2	505	err_out_region:
84af401a	506	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	507	err_out:
	508	return rc;
	509	}
	510
	511	static void __exit w83977f_wdt_exit(void)
	512	{
	513	wdt_stop();
	514	misc_deregister(&wdt_miscdev);
	515	unregister_reboot_notifier(&wdt_notifier);
84af401a	516	release_region(IO_INDEX_PORT, 2);
b4cc4aa2 JMG	517	}
	518
	519	module_init(w83977f_wdt_init);
	520	module_exit(w83977f_wdt_exit);
	521
	522	MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
	523	MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
	524	MODULE_LICENSE("GPL");