[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / wafer5823wdt.c

/*
 *	ICP Wafer 5823 Single Board Computer WDT driver
 *	http://www.icpamerica.com/wafer_5823.php
 *	May also work on other similar models
 *
 *	(c) Copyright 2002 Justin Cormack <justin@street-vision.com>
 *
 *	Release 0.02
 *
 *	Based on advantechwdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
 *						All Rights Reserved.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 */

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

#define WATCHDOG_NAME "Wafer 5823 WDT"
#define PFX WATCHDOG_NAME ": "
#define WD_TIMO 60			/* 60 sec default timeout */

static unsigned long wafwdt_is_open;
static char expect_close;
static DEFINE_SPINLOCK(wafwdt_lock);

/*
 *	You must set these - there is no sane way to probe for this board.
 *
 *	To enable, write the timeout value in seconds (1 to 255) to I/O
 *	port WDT_START, then read the port to start the watchdog. To pat
 *	the dog, read port WDT_STOP to stop the timer, then read WDT_START
 *	to restart it again.
 */

static int wdt_stop = 0x843;
static int wdt_start = 0x443;

static int timeout = WD_TIMO;  /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
				__MODULE_STRING(WD_TIMO) ".");

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) ")");

static void wafwdt_ping(void)
{
	/* pat watchdog */
	spin_lock(&wafwdt_lock);
	inb_p(wdt_stop);
	inb_p(wdt_start);
	spin_unlock(&wafwdt_lock);
}

static void wafwdt_start(void)
{
	/* start up watchdog */
	outb_p(timeout, wdt_start);
	inb_p(wdt_start);
}

static void wafwdt_stop(void)
{
	/* stop watchdog */
	inb_p(wdt_stop);
}

static ssize_t wafwdt_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 i;

			/* In case it was set long ago */
			expect_close = 0;

			/* scan to see whether or not we got the magic
			   character */
			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		/* Well, anyhow someone wrote to us, we should
		   return that favour */
		wafwdt_ping();
	}
	return count;
}

static long wafwdt_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 = 1,
		.identity = "Wafer 5823 WDT",
	};

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

	case WDIOC_GETSTATUS:
	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) {
			wafwdt_stop();
			retval = 0;
		}

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

		return retval;
	}

	case WDIOC_KEEPALIVE:
		wafwdt_ping();
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		if ((new_timeout < 1) || (new_timeout > 255))
			return -EINVAL;
		timeout = new_timeout;
		wafwdt_stop();
		wafwdt_start();
		/* Fall */
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);

	default:
		return -ENOTTY;
	}
	return 0;
}

static int wafwdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &wafwdt_is_open))
		return -EBUSY;

	/*
	 *      Activate
	 */
	wafwdt_start();
	return nonseekable_open(inode, file);
}

static int wafwdt_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		wafwdt_stop();
	else {
		pr_crit("WDT device closed unexpectedly.  WDT will not stop!\n");
		wafwdt_ping();
	}
	clear_bit(0, &wafwdt_is_open);
	expect_close = 0;
	return 0;
}

/*
 *	Notifier for system down
 */

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

/*
 *	Kernel Interfaces
 */

static const struct file_operations wafwdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wafwdt_write,
	.unlocked_ioctl	= wafwdt_ioctl,
	.open		= wafwdt_open,
	.release	= wafwdt_close,
};

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

/*
 *	The WDT needs to learn about soft shutdowns in order to
 *	turn the timebomb registers off.
 */

static struct notifier_block wafwdt_notifier = {
	.notifier_call = wafwdt_notify_sys,
};

static int __init wafwdt_init(void)
{
	int ret;

	pr_info("WDT driver for Wafer 5823 single board computer initialising\n");

	if (timeout < 1 || timeout > 255) {
		timeout = WD_TIMO;
		pr_info("timeout value must be 1 <= x <= 255, using %d\n",
			timeout);
	}

	if (wdt_stop != wdt_start) {
		if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
			pr_err("I/O address 0x%04x already in use\n", wdt_stop);
			ret = -EIO;
			goto error;
		}
	}

	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
		pr_err("I/O address 0x%04x already in use\n", wdt_start);
		ret = -EIO;
		goto error2;
	}

	ret = register_reboot_notifier(&wafwdt_notifier);
	if (ret != 0) {
		pr_err("cannot register reboot notifier (err=%d)\n", ret);
		goto error3;
	}

	ret = misc_register(&wafwdt_miscdev);
	if (ret != 0) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		goto error4;
	}

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

	return ret;
error4:
	unregister_reboot_notifier(&wafwdt_notifier);
error3:
	release_region(wdt_start, 1);
error2:
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
error:
	return ret;
}

static void __exit wafwdt_exit(void)
{
	misc_deregister(&wafwdt_miscdev);
	unregister_reboot_notifier(&wafwdt_notifier);
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
	release_region(wdt_start, 1);
}

module_init(wafwdt_init);
module_exit(wafwdt_exit);

MODULE_AUTHOR("Justin Cormack");
MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

/* end of wafer5823wdt.c */
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* ICP Wafer 5823 Single Board Computer WDT driver
7944d3a5 WVS	3	* http://www.icpamerica.com/wafer_5823.php
7944d3a5 WVS	4	* May also work on other similar models
1da177e4 LT	5	*
	6	* (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
	7	*
7944d3a5	8	* Release 0.02
1da177e4 LT	9	*
	10	* Based on advantechwdt.c which is based on wdt.c.
	11	* Original copyright messages:
	12	*
29fa0586 AC	13	* (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
29fa0586 AC	14	* All Rights Reserved.
1da177e4 LT	15	*
	16	* This program is free software; you can redistribute it and/or
	17	* modify it under the terms of the GNU General Public License
	18	* as published by the Free Software Foundation; either version
	19	* 2 of the License, or (at your option) any later version.
	20	*
	21	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	22	* warranty for any of this software. This material is provided
	23	* "AS-IS" and at no charge.
	24	*
	25	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
	26	*
	27	*/
	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/fs.h>
	36	#include <linux/ioport.h>
	37	#include <linux/notifier.h>
	38	#include <linux/reboot.h>
	39	#include <linux/init.h>
	40	#include <linux/spinlock.h>
694b16b2 AC	41	#include <linux/io.h>
694b16b2 AC	42	#include <linux/uaccess.h>
1da177e4 LT	43
	44	#define WATCHDOG_NAME "Wafer 5823 WDT"
	45	#define PFX WATCHDOG_NAME ": "
	46	#define WD_TIMO 60 /* 60 sec default timeout */
	47
	48	static unsigned long wafwdt_is_open;
	49	static char expect_close;
c7dfd0cc	50	static DEFINE_SPINLOCK(wafwdt_lock);
1da177e4 LT	51
	52	/*
	53	* You must set these - there is no sane way to probe for this board.
	54	*
7944d3a5 WVS	55	* To enable, write the timeout value in seconds (1 to 255) to I/O
	56	* port WDT_START, then read the port to start the watchdog. To pat
	57	* the dog, read port WDT_STOP to stop the timer, then read WDT_START
	58	* to restart it again.
1da177e4 LT	59	*/
	60
	61	static int wdt_stop = 0x843;
	62	static int wdt_start = 0x443;
	63
	64	static int timeout = WD_TIMO; /* in seconds */
	65	module_param(timeout, int, 0);
694b16b2 AC	66	MODULE_PARM_DESC(timeout,
	67	"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
	68	__MODULE_STRING(WD_TIMO) ".");
1da177e4	69
86a1e189 WVS	70	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	71	module_param(nowayout, bool, 0);
694b16b2 AC	72	MODULE_PARM_DESC(nowayout,
	73	"Watchdog cannot be stopped once started (default="
	74	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	75
	76	static void wafwdt_ping(void)
	77	{
	78	/* pat watchdog */
	79	spin_lock(&wafwdt_lock);
	80	inb_p(wdt_stop);
	81	inb_p(wdt_start);
	82	spin_unlock(&wafwdt_lock);
	83	}
	84
	85	static void wafwdt_start(void)
	86	{
	87	/* start up watchdog */
	88	outb_p(timeout, wdt_start);
	89	inb_p(wdt_start);
	90	}
	91
7944d3a5	92	static void wafwdt_stop(void)
1da177e4 LT	93	{
	94	/* stop watchdog */
	95	inb_p(wdt_stop);
	96	}
	97
694b16b2 AC	98	static ssize_t wafwdt_write(struct file file, const char __user buf,
694b16b2 AC	99	size_t count, loff_t *ppos)
1da177e4 LT	100	{
	101	/* See if we got the magic character 'V' and reload the timer */
	102	if (count) {
	103	if (!nowayout) {
	104	size_t i;
	105
	106	/* In case it was set long ago */
	107	expect_close = 0;
	108
694b16b2 AC	109	/* scan to see whether or not we got the magic
694b16b2 AC	110	character */
1da177e4 LT	111	for (i = 0; i != count; i++) {
	112	char c;
	113	if (get_user(c, buf + i))
	114	return -EFAULT;
	115	if (c == 'V')
	116	expect_close = 42;
	117	}
	118	}
694b16b2 AC	119	/* Well, anyhow someone wrote to us, we should
694b16b2 AC	120	return that favour */
1da177e4 LT	121	wafwdt_ping();
	122	}
	123	return count;
	124	}
	125
694b16b2 AC	126	static long wafwdt_ioctl(struct file *file, unsigned int cmd,
694b16b2 AC	127	unsigned long arg)
1da177e4 LT	128	{
	129	int new_timeout;
	130	void __user argp = (void __user )arg;
	131	int __user *p = argp;
694b16b2 AC	132	static const struct watchdog_info ident = {
	133	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	134	WDIOF_MAGICCLOSE,
1da177e4 LT	135	.firmware_version = 1,
	136	.identity = "Wafer 5823 WDT",
	137	};
	138
	139	switch (cmd) {
	140	case WDIOC_GETSUPPORT:
694b16b2	141	if (copy_to_user(argp, &ident, sizeof(ident)))
1da177e4 LT	142	return -EFAULT;
	143	break;
	144
	145	case WDIOC_GETSTATUS:
	146	case WDIOC_GETBOOTSTATUS:
	147	return put_user(0, p);
	148
1da177e4 LT	149	case WDIOC_SETOPTIONS:
	150	{
	151	int options, retval = -EINVAL;
	152
	153	if (get_user(options, p))
	154	return -EFAULT;
	155
	156	if (options & WDIOS_DISABLECARD) {
8a062ac6	157	wafwdt_stop();
1da177e4 LT	158	retval = 0;
	159	}
	160
	161	if (options & WDIOS_ENABLECARD) {
8a062ac6	162	wafwdt_start();
1da177e4 LT	163	retval = 0;
	164	}
	165
	166	return retval;
	167	}
	168
0c06090c WVS	169	case WDIOC_KEEPALIVE:
	170	wafwdt_ping();
	171	break;
	172
	173	case WDIOC_SETTIMEOUT:
	174	if (get_user(new_timeout, p))
	175	return -EFAULT;
	176	if ((new_timeout < 1) \|\| (new_timeout > 255))
	177	return -EINVAL;
	178	timeout = new_timeout;
	179	wafwdt_stop();
	180	wafwdt_start();
	181	/* Fall */
	182	case WDIOC_GETTIMEOUT:
	183	return put_user(timeout, p);
	184
1da177e4	185	default:
795b89d2	186	return -ENOTTY;
1da177e4 LT	187	}
	188	return 0;
	189	}
	190
	191	static int wafwdt_open(struct inode inode, struct file file)
	192	{
	193	if (test_and_set_bit(0, &wafwdt_is_open))
	194	return -EBUSY;
	195
	196	/*
	197	* Activate
	198	*/
	199	wafwdt_start();
	200	return nonseekable_open(inode, file);
	201	}
	202
7944d3a5	203	static int wafwdt_close(struct inode inode, struct file file)
1da177e4	204	{
694b16b2	205	if (expect_close == 42)
1da177e4	206	wafwdt_stop();
694b16b2	207	else {
27c766aa	208	pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4 LT	209	wafwdt_ping();
	210	}
	211	clear_bit(0, &wafwdt_is_open);
	212	expect_close = 0;
	213	return 0;
	214	}
	215
	216	/*
	217	* Notifier for system down
	218	*/
	219
694b16b2 AC	220	static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
694b16b2 AC	221	void *unused)
1da177e4	222	{
694b16b2	223	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	224	wafwdt_stop();
1da177e4 LT	225	return NOTIFY_DONE;
	226	}
	227
	228	/*
	229	* Kernel Interfaces
	230	*/
	231
62322d25	232	static const struct file_operations wafwdt_fops = {
1da177e4 LT	233	.owner = THIS_MODULE,
	234	.llseek = no_llseek,
	235	.write = wafwdt_write,
694b16b2	236	.unlocked_ioctl = wafwdt_ioctl,
1da177e4 LT	237	.open = wafwdt_open,
	238	.release = wafwdt_close,
	239	};
	240
	241	static struct miscdevice wafwdt_miscdev = {
	242	.minor = WATCHDOG_MINOR,
	243	.name = "watchdog",
	244	.fops = &wafwdt_fops,
	245	};
	246
	247	/*
	248	* The WDT needs to learn about soft shutdowns in order to
	249	* turn the timebomb registers off.
	250	*/
	251
	252	static struct notifier_block wafwdt_notifier = {
	253	.notifier_call = wafwdt_notify_sys,
	254	};
	255
	256	static int __init wafwdt_init(void)
	257	{
	258	int ret;
	259
27c766aa	260	pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
1da177e4	261
1da177e4 LT	262	if (timeout < 1 \|\| timeout > 255) {
1da177e4 LT	263	timeout = WD_TIMO;
27c766aa JP	264	pr_info("timeout value must be 1 <= x <= 255, using %d\n",
27c766aa JP	265	timeout);
1da177e4 LT	266	}
	267
	268	if (wdt_stop != wdt_start) {
694b16b2	269	if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
27c766aa	270	pr_err("I/O address 0x%04x already in use\n", wdt_stop);
1da177e4 LT	271	ret = -EIO;
	272	goto error;
	273	}
	274	}
	275
694b16b2	276	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
27c766aa	277	pr_err("I/O address 0x%04x already in use\n", wdt_start);
1da177e4 LT	278	ret = -EIO;
	279	goto error2;
	280	}
	281
	282	ret = register_reboot_notifier(&wafwdt_notifier);
	283	if (ret != 0) {
27c766aa	284	pr_err("cannot register reboot notifier (err=%d)\n", ret);
1da177e4 LT	285	goto error3;
	286	}
	287
	288	ret = misc_register(&wafwdt_miscdev);
	289	if (ret != 0) {
27c766aa JP	290	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	291	WATCHDOG_MINOR, ret);
1da177e4 LT	292	goto error4;
	293	}
	294
27c766aa	295	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	296	timeout, nowayout);
	297
	298	return ret;
	299	error4:
	300	unregister_reboot_notifier(&wafwdt_notifier);
	301	error3:
	302	release_region(wdt_start, 1);
	303	error2:
	304	if (wdt_stop != wdt_start)
	305	release_region(wdt_stop, 1);
	306	error:
	307	return ret;
	308	}
	309
	310	static void __exit wafwdt_exit(void)
	311	{
	312	misc_deregister(&wafwdt_miscdev);
	313	unregister_reboot_notifier(&wafwdt_notifier);
694b16b2	314	if (wdt_stop != wdt_start)
1da177e4 LT	315	release_region(wdt_stop, 1);
	316	release_region(wdt_start, 1);
	317	}
	318
	319	module_init(wafwdt_init);
	320	module_exit(wafwdt_exit);
	321
	322	MODULE_AUTHOR("Justin Cormack");
	323	MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
	324	MODULE_LICENSE("GPL");
	325	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	326
	327	/* end of wafer5823wdt.c */