[mirror_ubuntu-eoan-kernel.git] / drivers / watchdog / sc1200wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
 *	(c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
 *			All Rights Reserved.
 *	Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
 *
 *	The author(s) of this software shall not be held liable for damages
 *	of any nature resulting due to the use of this software. This
 *	software is provided AS-IS with no warranties.
 *
 *	Changelog:
 *	20020220 Zwane Mwaikambo	Code based on datasheet, no hardware.
 *	20020221 Zwane Mwaikambo	Cleanups as suggested by Jeff Garzik
 *					and Alan Cox.
 *	20020222 Zwane Mwaikambo	Added probing.
 *	20020225 Zwane Mwaikambo	Added ISAPNP support.
 *	20020412 Rob Radez		Broke out start/stop functions
 *		 <rob@osinvestor.com>	Return proper status instead of
 *					temperature warning
 *					Add WDIOC_GETBOOTSTATUS and
 *					WDIOC_SETOPTIONS ioctls
 *					Fix CONFIG_WATCHDOG_NOWAYOUT
 *	20020530 Joel Becker		Add Matt Domsch's nowayout module
 *					option
 *	20030116 Adam Belay		Updated to the latest pnp code
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

#define SC1200_MODULE_VER	"build 20020303"
#define SC1200_MODULE_NAME	"sc1200wdt"

#define	MAX_TIMEOUT	255	/* 255 minutes */
#define PMIR		(io)	/* Power Management Index Register */
#define PMDR		(io+1)	/* Power Management Data Register */

/* Data Register indexes */
#define FER1		0x00	/* Function enable register 1 */
#define FER2		0x01	/* Function enable register 2 */
#define PMC1		0x02	/* Power Management Ctrl 1 */
#define PMC2		0x03	/* Power Management Ctrl 2 */
#define PMC3		0x04	/* Power Management Ctrl 3 */
#define WDTO		0x05	/* Watchdog timeout register */
#define	WDCF		0x06	/* Watchdog config register */
#define WDST		0x07	/* Watchdog status register */

/* WDCF bitfields - which devices assert WDO */
#define KBC_IRQ		0x01	/* Keyboard Controller */
#define MSE_IRQ		0x02	/* Mouse */
#define UART1_IRQ	0x03	/* Serial0 */
#define UART2_IRQ	0x04	/* Serial1 */
/* 5 -7 are reserved */

static int timeout = 1;
static int io = -1;
static int io_len = 2;		/* for non plug and play */
static unsigned long open_flag;
static char expect_close;
static DEFINE_SPINLOCK(sc1200wdt_lock);	/* io port access serialisation */

#if defined CONFIG_PNP
static int isapnp = 1;
static struct pnp_dev *wdt_dev;

module_param(isapnp, int, 0);
MODULE_PARM_DESC(isapnp,
	"When set to 0 driver ISA PnP support will be disabled");
#endif

module_param_hw(io, int, ioport, 0);
MODULE_PARM_DESC(io, "io port");
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");

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) ")");


/* Read from Data Register */
static inline void __sc1200wdt_read_data(unsigned char index,
						unsigned char *data)
{
	outb_p(index, PMIR);
	*data = inb(PMDR);
}

static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
{
	spin_lock(&sc1200wdt_lock);
	__sc1200wdt_read_data(index, data);
	spin_unlock(&sc1200wdt_lock);
}

/* Write to Data Register */
static inline void __sc1200wdt_write_data(unsigned char index,
						unsigned char data)
{
	outb_p(index, PMIR);
	outb(data, PMDR);
}

static inline void sc1200wdt_write_data(unsigned char index,
						unsigned char data)
{
	spin_lock(&sc1200wdt_lock);
	__sc1200wdt_write_data(index, data);
	spin_unlock(&sc1200wdt_lock);
}


static void sc1200wdt_start(void)
{
	unsigned char reg;
	spin_lock(&sc1200wdt_lock);

	__sc1200wdt_read_data(WDCF, &reg);
	/* assert WDO when any of the following interrupts are triggered too */
	reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
	__sc1200wdt_write_data(WDCF, reg);
	/* set the timeout and get the ball rolling */
	__sc1200wdt_write_data(WDTO, timeout);

	spin_unlock(&sc1200wdt_lock);
}

static void sc1200wdt_stop(void)
{
	sc1200wdt_write_data(WDTO, 0);
}

/* This returns the status of the WDO signal, inactive high. */
static inline int sc1200wdt_status(void)
{
	unsigned char ret;

	sc1200wdt_read_data(WDST, &ret);
	/* If the bit is inactive, the watchdog is enabled, so return
	 * KEEPALIVEPING which is a bit of a kludge because there's nothing
	 * else for enabled/disabled status
	 */
	return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
}

static int sc1200wdt_open(struct inode *inode, struct file *file)
{
	/* allow one at a time */
	if (test_and_set_bit(0, &open_flag))
		return -EBUSY;

	if (timeout > MAX_TIMEOUT)
		timeout = MAX_TIMEOUT;

	sc1200wdt_start();
	pr_info("Watchdog enabled, timeout = %d min(s)", timeout);

	return stream_open(inode, file);
}


static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
						unsigned long arg)
{
	int new_timeout;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static const struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
							WDIOF_MAGICCLOSE,
		.firmware_version = 0,
		.identity = "PC87307/PC97307",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		return 0;

	case WDIOC_GETSTATUS:
		return put_user(sc1200wdt_status(), p);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;

		if (get_user(options, p))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			sc1200wdt_stop();
			retval = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			sc1200wdt_start();
			retval = 0;
		}

		return retval;
	}
	case WDIOC_KEEPALIVE:
		sc1200wdt_write_data(WDTO, timeout);
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			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;
		sc1200wdt_write_data(WDTO, timeout);
		/* fall through - and return the new timeout */

	case WDIOC_GETTIMEOUT:
		return put_user(timeout * 60, p);

	default:
		return -ENOTTY;
	}
}


static int sc1200wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		sc1200wdt_stop();
		pr_info("Watchdog disabled\n");
	} else {
		sc1200wdt_write_data(WDTO, timeout);
		pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout);
	}
	clear_bit(0, &open_flag);
	expect_close = 0;

	return 0;
}


static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
						size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}

		sc1200wdt_write_data(WDTO, timeout);
		return len;
	}

	return 0;
}


static int sc1200wdt_notify_sys(struct notifier_block *this,
					unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		sc1200wdt_stop();

	return NOTIFY_DONE;
}


static struct notifier_block sc1200wdt_notifier = {
	.notifier_call =	sc1200wdt_notify_sys,
};

static const struct file_operations sc1200wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= sc1200wdt_write,
	.unlocked_ioctl = sc1200wdt_ioctl,
	.open		= sc1200wdt_open,
	.release	= sc1200wdt_release,
};

static struct miscdevice sc1200wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &sc1200wdt_fops,
};


static int __init sc1200wdt_probe(void)
{
	/* The probe works by reading the PMC3 register's default value of 0x0e
	 * there is one caveat, if the device disables the parallel port or any
	 * of the UARTs we won't be able to detect it.
	 * NB. This could be done with accuracy by reading the SID registers,
	 * but we don't have access to those io regions.
	 */

	unsigned char reg;

	sc1200wdt_read_data(PMC3, &reg);
	reg &= 0x0f;		/* we don't want the UART busy bits */
	return (reg == 0x0e) ? 0 : -ENODEV;
}


#if defined CONFIG_PNP

static const struct pnp_device_id scl200wdt_pnp_devices[] = {
	/* National Semiconductor PC87307/PC97307 watchdog component */
	{.id = "NSC0800", .driver_data = 0},
	{.id = ""},
};

static int scl200wdt_pnp_probe(struct pnp_dev *dev,
					const struct pnp_device_id *dev_id)
{
	/* this driver only supports one card at a time */
	if (wdt_dev || !isapnp)
		return -EBUSY;

	wdt_dev = dev;
	io = pnp_port_start(wdt_dev, 0);
	io_len = pnp_port_len(wdt_dev, 0);

	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
		pr_err("Unable to register IO port %#x\n", io);
		return -EBUSY;
	}

	pr_info("PnP device found at io port %#x/%d\n", io, io_len);
	return 0;
}

static void scl200wdt_pnp_remove(struct pnp_dev *dev)
{
	if (wdt_dev) {
		release_region(io, io_len);
		wdt_dev = NULL;
	}
}

static struct pnp_driver scl200wdt_pnp_driver = {
	.name		= "scl200wdt",
	.id_table	= scl200wdt_pnp_devices,
	.probe		= scl200wdt_pnp_probe,
	.remove		= scl200wdt_pnp_remove,
};

#endif /* CONFIG_PNP */


static int __init sc1200wdt_init(void)
{
	int ret;

	pr_info("%s\n", SC1200_MODULE_VER);

#if defined CONFIG_PNP
	if (isapnp) {
		ret = pnp_register_driver(&scl200wdt_pnp_driver);
		if (ret)
			goto out_clean;
	}
#endif

	if (io == -1) {
		pr_err("io parameter must be specified\n");
		ret = -EINVAL;
		goto out_pnp;
	}

#if defined CONFIG_PNP
	/* now that the user has specified an IO port and we haven't detected
	 * any devices, disable pnp support */
	if (isapnp)
		pnp_unregister_driver(&scl200wdt_pnp_driver);
	isapnp = 0;
#endif

	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
		pr_err("Unable to register IO port %#x\n", io);
		ret = -EBUSY;
		goto out_pnp;
	}

	ret = sc1200wdt_probe();
	if (ret)
		goto out_io;

	ret = register_reboot_notifier(&sc1200wdt_notifier);
	if (ret) {
		pr_err("Unable to register reboot notifier err = %d\n", ret);
		goto out_io;
	}

	ret = misc_register(&sc1200wdt_miscdev);
	if (ret) {
		pr_err("Unable to register miscdev on minor %d\n",
		       WATCHDOG_MINOR);
		goto out_rbt;
	}

	/* ret = 0 */

out_clean:
	return ret;

out_rbt:
	unregister_reboot_notifier(&sc1200wdt_notifier);

out_io:
	release_region(io, io_len);

out_pnp:
#if defined CONFIG_PNP
	if (isapnp)
		pnp_unregister_driver(&scl200wdt_pnp_driver);
#endif
	goto out_clean;
}


static void __exit sc1200wdt_exit(void)
{
	misc_deregister(&sc1200wdt_miscdev);
	unregister_reboot_notifier(&sc1200wdt_notifier);

#if defined CONFIG_PNP
	if (isapnp)
		pnp_unregister_driver(&scl200wdt_pnp_driver);
	else
#endif
	release_region(io, io_len);
}

module_init(sc1200wdt_init);
module_exit(sc1200wdt_exit);

MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
MODULE_DESCRIPTION(
	"Driver for National Semiconductor PC87307/PC97307 watchdog component");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
	4	* (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
	5	* All Rights Reserved.
	6	* Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
	7	*
1da177e4 LT	8	* The author(s) of this software shall not be held liable for damages
	9	* of any nature resulting due to the use of this software. This
	10	* software is provided AS-IS with no warranties.
	11	*
	12	* Changelog:
	13	* 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
103a1d5c AC	14	* 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik
103a1d5c AC	15	* and Alan Cox.
1da177e4 LT	16	* 20020222 Zwane Mwaikambo Added probing.
	17	* 20020225 Zwane Mwaikambo Added ISAPNP support.
	18	* 20020412 Rob Radez Broke out start/stop functions
103a1d5c AC	19	* <rob@osinvestor.com> Return proper status instead of
	20	* temperature warning
	21	* Add WDIOC_GETBOOTSTATUS and
	22	* WDIOC_SETOPTIONS ioctls
1da177e4	23	* Fix CONFIG_WATCHDOG_NOWAYOUT
103a1d5c AC	24	* 20020530 Joel Becker Add Matt Domsch's nowayout module
103a1d5c AC	25	* option
1da177e4	26	* 20030116 Adam Belay Updated to the latest pnp code
1da177e4 LT	27	*/
1da177e4 LT	28
27c766aa JP	29	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	30
1da177e4 LT	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/miscdevice.h>
	34	#include <linux/watchdog.h>
	35	#include <linux/ioport.h>
	36	#include <linux/spinlock.h>
	37	#include <linux/notifier.h>
	38	#include <linux/reboot.h>
	39	#include <linux/init.h>
	40	#include <linux/pnp.h>
	41	#include <linux/fs.h>
6188e10d	42	#include <linux/semaphore.h>
103a1d5c AC	43	#include <linux/io.h>
103a1d5c AC	44	#include <linux/uaccess.h>
1da177e4 LT	45
	46	#define SC1200_MODULE_VER "build 20020303"
	47	#define SC1200_MODULE_NAME "sc1200wdt"
1da177e4 LT	48
	49	#define MAX_TIMEOUT 255 /* 255 minutes */
	50	#define PMIR (io) /* Power Management Index Register */
	51	#define PMDR (io+1) /* Power Management Data Register */
	52
	53	/* Data Register indexes */
	54	#define FER1 0x00 /* Function enable register 1 */
	55	#define FER2 0x01 /* Function enable register 2 */
	56	#define PMC1 0x02 /* Power Management Ctrl 1 */
	57	#define PMC2 0x03 /* Power Management Ctrl 2 */
	58	#define PMC3 0x04 /* Power Management Ctrl 3 */
	59	#define WDTO 0x05 /* Watchdog timeout register */
	60	#define WDCF 0x06 /* Watchdog config register */
	61	#define WDST 0x07 /* Watchdog status register */
	62
	63	/* WDCF bitfields - which devices assert WDO */
	64	#define KBC_IRQ 0x01 /* Keyboard Controller */
	65	#define MSE_IRQ 0x02 /* Mouse */
	66	#define UART1_IRQ 0x03 /* Serial0 */
	67	#define UART2_IRQ 0x04 /* Serial1 */
	68	/* 5 -7 are reserved */
	69
1da177e4 LT	70	static int timeout = 1;
	71	static int io = -1;
	72	static int io_len = 2; /* for non plug and play */
103a1d5c	73	static unsigned long open_flag;
1da177e4	74	static char expect_close;
c7dfd0cc	75	static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
1da177e4 LT	76
	77	#if defined CONFIG_PNP
	78	static int isapnp = 1;
	79	static struct pnp_dev *wdt_dev;
	80
	81	module_param(isapnp, int, 0);
103a1d5c AC	82	MODULE_PARM_DESC(isapnp,
103a1d5c AC	83	"When set to 0 driver ISA PnP support will be disabled");
1da177e4 LT	84	#endif
1da177e4 LT	85
5d1c93ce	86	module_param_hw(io, int, ioport, 0);
1da177e4 LT	87	MODULE_PARM_DESC(io, "io port");
	88	module_param(timeout, int, 0);
	89	MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
	90
86a1e189 WVS	91	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	92	module_param(nowayout, bool, 0);
103a1d5c AC	93	MODULE_PARM_DESC(nowayout,
	94	"Watchdog cannot be stopped once started (default="
	95	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	96
	97
	98
	99	/* Read from Data Register */
103a1d5c AC	100	static inline void __sc1200wdt_read_data(unsigned char index,
103a1d5c AC	101	unsigned char *data)
1da177e4	102	{
1da177e4 LT	103	outb_p(index, PMIR);
1da177e4 LT	104	*data = inb(PMDR);
1da177e4 LT	105	}
1da177e4 LT	106
103a1d5c AC	107	static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
	108	{
	109	spin_lock(&sc1200wdt_lock);
	110	__sc1200wdt_read_data(index, data);
	111	spin_unlock(&sc1200wdt_lock);
	112	}
1da177e4 LT	113
1da177e4 LT	114	/* Write to Data Register */
103a1d5c AC	115	static inline void __sc1200wdt_write_data(unsigned char index,
103a1d5c AC	116	unsigned char data)
1da177e4	117	{
1da177e4 LT	118	outb_p(index, PMIR);
1da177e4 LT	119	outb(data, PMDR);
103a1d5c AC	120	}
	121
	122	static inline void sc1200wdt_write_data(unsigned char index,
	123	unsigned char data)
	124	{
	125	spin_lock(&sc1200wdt_lock);
	126	__sc1200wdt_write_data(index, data);
1da177e4 LT	127	spin_unlock(&sc1200wdt_lock);
	128	}
	129
	130
	131	static void sc1200wdt_start(void)
	132	{
	133	unsigned char reg;
103a1d5c	134	spin_lock(&sc1200wdt_lock);
1da177e4	135
103a1d5c	136	__sc1200wdt_read_data(WDCF, &reg);
1da177e4 LT	137	/* assert WDO when any of the following interrupts are triggered too */
1da177e4 LT	138	reg \|= (KBC_IRQ \| MSE_IRQ \| UART1_IRQ \| UART2_IRQ);
103a1d5c	139	__sc1200wdt_write_data(WDCF, reg);
1da177e4	140	/* set the timeout and get the ball rolling */
103a1d5c	141	__sc1200wdt_write_data(WDTO, timeout);
1da177e4	142
103a1d5c AC	143	spin_unlock(&sc1200wdt_lock);
103a1d5c AC	144	}
1da177e4 LT	145
	146	static void sc1200wdt_stop(void)
	147	{
	148	sc1200wdt_write_data(WDTO, 0);
	149	}
	150
1da177e4 LT	151	/* This returns the status of the WDO signal, inactive high. */
	152	static inline int sc1200wdt_status(void)
	153	{
	154	unsigned char ret;
	155
	156	sc1200wdt_read_data(WDST, &ret);
	157	/* If the bit is inactive, the watchdog is enabled, so return
	158	* KEEPALIVEPING which is a bit of a kludge because there's nothing
	159	* else for enabled/disabled status
	160	*/
103a1d5c	161	return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
1da177e4 LT	162	}
1da177e4 LT	163
1da177e4 LT	164	static int sc1200wdt_open(struct inode inode, struct file file)
1da177e4 LT	165	{
1da177e4	166	/* allow one at a time */
103a1d5c	167	if (test_and_set_bit(0, &open_flag))
1da177e4 LT	168	return -EBUSY;
	169
	170	if (timeout > MAX_TIMEOUT)
	171	timeout = MAX_TIMEOUT;
	172
	173	sc1200wdt_start();
27c766aa	174	pr_info("Watchdog enabled, timeout = %d min(s)", timeout);
1da177e4	175
c5bf68fe	176	return stream_open(inode, file);
1da177e4 LT	177	}
	178
	179
103a1d5c AC	180	static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
103a1d5c AC	181	unsigned long arg)
1da177e4 LT	182	{
	183	int new_timeout;
	184	void __user argp = (void __user )arg;
	185	int __user *p = argp;
103a1d5c AC	186	static const struct watchdog_info ident = {
	187	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	188	WDIOF_MAGICCLOSE,
1da177e4 LT	189	.firmware_version = 0,
	190	.identity = "PC87307/PC97307",
	191	};
	192
	193	switch (cmd) {
103a1d5c	194	case WDIOC_GETSUPPORT:
e04ab958	195	if (copy_to_user(argp, &ident, sizeof(ident)))
103a1d5c AC	196	return -EFAULT;
103a1d5c AC	197	return 0;
1da177e4	198
103a1d5c AC	199	case WDIOC_GETSTATUS:
103a1d5c AC	200	return put_user(sc1200wdt_status(), p);
1da177e4	201
103a1d5c AC	202	case WDIOC_GETBOOTSTATUS:
103a1d5c AC	203	return put_user(0, p);
1da177e4	204
103a1d5c AC	205	case WDIOC_SETOPTIONS:
	206	{
	207	int options, retval = -EINVAL;
1da177e4	208
103a1d5c AC	209	if (get_user(options, p))
103a1d5c AC	210	return -EFAULT;
1da177e4	211
103a1d5c AC	212	if (options & WDIOS_DISABLECARD) {
	213	sc1200wdt_stop();
	214	retval = 0;
	215	}
1da177e4	216
103a1d5c AC	217	if (options & WDIOS_ENABLECARD) {
	218	sc1200wdt_start();
	219	retval = 0;
1da177e4	220	}
103a1d5c AC	221
	222	return retval;
	223	}
0c06090c WVS	224	case WDIOC_KEEPALIVE:
	225	sc1200wdt_write_data(WDTO, timeout);
	226	return 0;
	227
	228	case WDIOC_SETTIMEOUT:
	229	if (get_user(new_timeout, p))
	230	return -EFAULT;
	231	/* the API states this is given in secs */
	232	new_timeout /= 60;
	233	if (new_timeout < 0 \|\| new_timeout > MAX_TIMEOUT)
	234	return -EINVAL;
	235	timeout = new_timeout;
	236	sc1200wdt_write_data(WDTO, timeout);
51c802f5	237	/* fall through - and return the new timeout */
0c06090c WVS	238
	239	case WDIOC_GETTIMEOUT:
	240	return put_user(timeout * 60, p);
	241
103a1d5c AC	242	default:
103a1d5c AC	243	return -ENOTTY;
1da177e4 LT	244	}
	245	}
	246
	247
	248	static int sc1200wdt_release(struct inode inode, struct file file)
	249	{
	250	if (expect_close == 42) {
	251	sc1200wdt_stop();
27c766aa	252	pr_info("Watchdog disabled\n");
1da177e4 LT	253	} else {
1da177e4 LT	254	sc1200wdt_write_data(WDTO, timeout);
27c766aa	255	pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout);
1da177e4	256	}
103a1d5c	257	clear_bit(0, &open_flag);
1da177e4 LT	258	expect_close = 0;
	259
	260	return 0;
	261	}
	262
	263
103a1d5c AC	264	static ssize_t sc1200wdt_write(struct file file, const char __user data,
103a1d5c AC	265	size_t len, loff_t *ppos)
1da177e4 LT	266	{
	267	if (len) {
	268	if (!nowayout) {
	269	size_t i;
	270
	271	expect_close = 0;
	272
	273	for (i = 0; i != len; i++) {
	274	char c;
	275
7944d3a5	276	if (get_user(c, data + i))
1da177e4 LT	277	return -EFAULT;
	278	if (c == 'V')
	279	expect_close = 42;
	280	}
	281	}
	282
	283	sc1200wdt_write_data(WDTO, timeout);
	284	return len;
	285	}
	286
	287	return 0;
	288	}
	289
	290
103a1d5c AC	291	static int sc1200wdt_notify_sys(struct notifier_block *this,
103a1d5c AC	292	unsigned long code, void *unused)
1da177e4 LT	293	{
	294	if (code == SYS_DOWN \|\| code == SYS_HALT)
	295	sc1200wdt_stop();
	296
	297	return NOTIFY_DONE;
	298	}
	299
	300
103a1d5c	301	static struct notifier_block sc1200wdt_notifier = {
1da177e4 LT	302	.notifier_call = sc1200wdt_notify_sys,
	303	};
	304
103a1d5c	305	static const struct file_operations sc1200wdt_fops = {
1da177e4 LT	306	.owner = THIS_MODULE,
	307	.llseek = no_llseek,
	308	.write = sc1200wdt_write,
103a1d5c	309	.unlocked_ioctl = sc1200wdt_ioctl,
1da177e4 LT	310	.open = sc1200wdt_open,
	311	.release = sc1200wdt_release,
	312	};
	313
103a1d5c	314	static struct miscdevice sc1200wdt_miscdev = {
1da177e4 LT	315	.minor = WATCHDOG_MINOR,
	316	.name = "watchdog",
	317	.fops = &sc1200wdt_fops,
	318	};
	319
	320
	321	static int __init sc1200wdt_probe(void)
	322	{
	323	/* The probe works by reading the PMC3 register's default value of 0x0e
	324	* there is one caveat, if the device disables the parallel port or any
	325	* of the UARTs we won't be able to detect it.
103a1d5c AC	326	* NB. This could be done with accuracy by reading the SID registers,
103a1d5c AC	327	* but we don't have access to those io regions.
1da177e4 LT	328	*/
	329
	330	unsigned char reg;
	331
	332	sc1200wdt_read_data(PMC3, &reg);
103a1d5c	333	reg &= 0x0f; /* we don't want the UART busy bits */
1da177e4 LT	334	return (reg == 0x0e) ? 0 : -ENODEV;
	335	}
	336
	337
	338	#if defined CONFIG_PNP
	339
39ad8089	340	static const struct pnp_device_id scl200wdt_pnp_devices[] = {
1da177e4 LT	341	/* National Semiconductor PC87307/PC97307 watchdog component */
	342	{.id = "NSC0800", .driver_data = 0},
	343	{.id = ""},
	344	};
	345
103a1d5c AC	346	static int scl200wdt_pnp_probe(struct pnp_dev *dev,
103a1d5c AC	347	const struct pnp_device_id *dev_id)
1da177e4 LT	348	{
	349	/* this driver only supports one card at a time */
	350	if (wdt_dev \|\| !isapnp)
	351	return -EBUSY;
	352
	353	wdt_dev = dev;
	354	io = pnp_port_start(wdt_dev, 0);
	355	io_len = pnp_port_len(wdt_dev, 0);
	356
	357	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
27c766aa	358	pr_err("Unable to register IO port %#x\n", io);
1da177e4 LT	359	return -EBUSY;
	360	}
	361
27c766aa	362	pr_info("PnP device found at io port %#x/%d\n", io, io_len);
1da177e4 LT	363	return 0;
	364	}
	365
103a1d5c	366	static void scl200wdt_pnp_remove(struct pnp_dev *dev)
1da177e4	367	{
103a1d5c	368	if (wdt_dev) {
1da177e4 LT	369	release_region(io, io_len);
	370	wdt_dev = NULL;
	371	}
	372	}
	373
	374	static struct pnp_driver scl200wdt_pnp_driver = {
	375	.name = "scl200wdt",
	376	.id_table = scl200wdt_pnp_devices,
	377	.probe = scl200wdt_pnp_probe,
	378	.remove = scl200wdt_pnp_remove,
	379	};
	380
	381	#endif /* CONFIG_PNP */
	382
	383
	384	static int __init sc1200wdt_init(void)
	385	{
	386	int ret;
	387
27c766aa	388	pr_info("%s\n", SC1200_MODULE_VER);
1da177e4	389
1da177e4 LT	390	#if defined CONFIG_PNP
	391	if (isapnp) {
	392	ret = pnp_register_driver(&scl200wdt_pnp_driver);
	393	if (ret)
	394	goto out_clean;
	395	}
	396	#endif
	397
	398	if (io == -1) {
27c766aa	399	pr_err("io parameter must be specified\n");
1da177e4	400	ret = -EINVAL;
150ed8ed	401	goto out_pnp;
1da177e4 LT	402	}
	403
	404	#if defined CONFIG_PNP
	405	/* now that the user has specified an IO port and we haven't detected
	406	* any devices, disable pnp support */
dace8bbf A	407	if (isapnp)
dace8bbf A	408	pnp_unregister_driver(&scl200wdt_pnp_driver);
1da177e4	409	isapnp = 0;
1da177e4 LT	410	#endif
	411
	412	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
27c766aa	413	pr_err("Unable to register IO port %#x\n", io);
1da177e4	414	ret = -EBUSY;
150ed8ed	415	goto out_pnp;
1da177e4 LT	416	}
	417
	418	ret = sc1200wdt_probe();
	419	if (ret)
	420	goto out_io;
	421
	422	ret = register_reboot_notifier(&sc1200wdt_notifier);
	423	if (ret) {
27c766aa	424	pr_err("Unable to register reboot notifier err = %d\n", ret);
1da177e4 LT	425	goto out_io;
	426	}
	427
	428	ret = misc_register(&sc1200wdt_miscdev);
	429	if (ret) {
27c766aa JP	430	pr_err("Unable to register miscdev on minor %d\n",
27c766aa JP	431	WATCHDOG_MINOR);
1da177e4 LT	432	goto out_rbt;
	433	}
	434
	435	/* ret = 0 */
	436
	437	out_clean:
	438	return ret;
	439
	440	out_rbt:
	441	unregister_reboot_notifier(&sc1200wdt_notifier);
	442
	443	out_io:
	444	release_region(io, io_len);
	445
150ed8ed AM	446	out_pnp:
	447	#if defined CONFIG_PNP
	448	if (isapnp)
	449	pnp_unregister_driver(&scl200wdt_pnp_driver);
	450	#endif
1da177e4 LT	451	goto out_clean;
	452	}
	453
	454
	455	static void __exit sc1200wdt_exit(void)
	456	{
	457	misc_deregister(&sc1200wdt_miscdev);
	458	unregister_reboot_notifier(&sc1200wdt_notifier);
	459
	460	#if defined CONFIG_PNP
103a1d5c	461	if (isapnp)
1da177e4 LT	462	pnp_unregister_driver(&scl200wdt_pnp_driver);
	463	else
	464	#endif
	465	release_region(io, io_len);
	466	}
	467
	468	module_init(sc1200wdt_init);
	469	module_exit(sc1200wdt_exit);
	470
	471	MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
143a2e54 WVS	472	MODULE_DESCRIPTION(
143a2e54 WVS	473	"Driver for National Semiconductor PC87307/PC97307 watchdog component");
1da177e4	474	MODULE_LICENSE("GPL");