[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / char / watchdog / advantechwdt.c

/*
 *	Advantech Single Board Computer WDT driver
 *
 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
 *
 *	Based on acquirewdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
 *				http://www.redhat.com
 *
 *	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@redhat.com>
 *
 *	14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *	    Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *
 *	16-Oct-2002 Rob Radez <rob@osinvestor.com>
 *	    Clean up ioctls, clean up init + exit, add expect close support,
 *	    add wdt_start and wdt_stop as parameters.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.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 <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>

#define DRV_NAME "advantechwdt"
#define PFX DRV_NAME ": "
#define WATCHDOG_NAME "Advantech WDT"
#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */

static unsigned long advwdt_is_open;
static char adv_expect_close;

/*
 *	You must set these - there is no sane way to probe for this board.
 *
 *	To enable or restart, write the timeout value in seconds (1 to 63)
 *	to I/O port wdt_start.  To disable, read I/O port wdt_stop.
 *	Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
 *	check your manual (at least the PCA-6159 seems to be different -
 *	the manual says wdt_stop is 0x43, not 0x443).
 *	(0x43 is also a write-only control register for the 8254 timer!)
 */

static int wdt_stop = 0x443;
module_param(wdt_stop, int, 0);
MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");

static int wdt_start = 0x443;
module_param(wdt_start, int, 0);
MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");

static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");

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

/*
 *	Watchdog Operations
 */

static void
advwdt_ping(void)
{
	/* Write a watchdog value */
	outb_p(timeout, wdt_start);
}

static void
advwdt_disable(void)
{
	inb_p(wdt_stop);
}

static int
advwdt_set_heartbeat(int t)
{
	if ((t < 1) || (t > 63))
		return -EINVAL;

	timeout = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */

static ssize_t
advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			adv_expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf+i))
					return -EFAULT;
				if (c == 'V')
					adv_expect_close = 42;
			}
		}
		advwdt_ping();
	}
	return count;
}

static int
advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	  unsigned long arg)
{
	int new_timeout;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = WATCHDOG_NAME,
	};

	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_KEEPALIVE:
	  advwdt_ping();
	  break;

	case WDIOC_SETTIMEOUT:
	  if (get_user(new_timeout, p))
		  return -EFAULT;
	  if (advwdt_set_heartbeat(new_timeout))
		  return -EINVAL;
	  advwdt_ping();
	  /* Fall */

	case WDIOC_GETTIMEOUT:
	  return put_user(timeout, p);

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

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

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

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

	  return retval;
	}

	default:
	  return -ENOTTY;
	}
	return 0;
}

static int
advwdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &advwdt_is_open))
		return -EBUSY;
	/*
	 *	Activate
	 */

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

static int
advwdt_close(struct inode *inode, struct file *file)
{
	if (adv_expect_close == 42) {
		advwdt_disable();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		advwdt_ping();
	}
	clear_bit(0, &advwdt_is_open);
	adv_expect_close = 0;
	return 0;
}

/*
 *	Notifier for system down
 */

static int
advwdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT) {
		/* Turn the WDT off */
		advwdt_disable();
	}
	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static const struct file_operations advwdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= advwdt_write,
	.ioctl		= advwdt_ioctl,
	.open		= advwdt_open,
	.release	= advwdt_close,
};

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

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

static struct notifier_block advwdt_notifier = {
	.notifier_call = advwdt_notify_sys,
};

/*
 *	Init & exit routines
 */

static int __init
advwdt_init(void)
{
	int ret;

	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");

	if (wdt_stop != wdt_start) {
		if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
			printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
				wdt_stop);
			ret = -EIO;
			goto out;
		}
	}

	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
			wdt_start);
		ret = -EIO;
		goto unreg_stop;
	}

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (advwdt_set_heartbeat(timeout)) {
		advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
		printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
			timeout);
	}

	ret = register_reboot_notifier(&advwdt_notifier);
	if (ret != 0) {
		printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		goto unreg_regions;
	}

	ret = misc_register(&advwdt_miscdev);
	if (ret != 0) {
		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		goto unreg_reboot;
	}

	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);

out:
	return ret;
unreg_reboot:
	unregister_reboot_notifier(&advwdt_notifier);
unreg_regions:
	release_region(wdt_start, 1);
unreg_stop:
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
	goto out;
}

static void __exit
advwdt_exit(void)
{
	misc_deregister(&advwdt_miscdev);
	unregister_reboot_notifier(&advwdt_notifier);
	release_region(wdt_start,1);
	if(wdt_stop != wdt_start)
		release_region(wdt_stop,1);
}

module_init(advwdt_init);
module_exit(advwdt_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Advantech Single Board Computer WDT driver
	3	*
	4	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	5	*
	6	* Based on acquirewdt.c which is based on wdt.c.
	7	* Original copyright messages:
	8	*
	9	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	10	* http://www.redhat.com
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*
	17	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	18	* warranty for any of this software. This material is provided
	19	* "AS-IS" and at no charge.
	20	*
	21	* (c) Copyright 1995 Alan Cox <alan@redhat.com>
	22	*
	23	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	24	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	25	*
	26	* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
	27	* Clean up ioctls, clean up init + exit, add expect close support,
	28	* add wdt_start and wdt_stop as parameters.
	29	*/
	30
	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/types.h>
	34	#include <linux/miscdevice.h>
	35	#include <linux/watchdog.h>
	36	#include <linux/fs.h>
	37	#include <linux/ioport.h>
	38	#include <linux/notifier.h>
	39	#include <linux/reboot.h>
	40	#include <linux/init.h>
	41
	42	#include <asm/io.h>
	43	#include <asm/uaccess.h>
	44	#include <asm/system.h>
	45
1d747be6 WVS	46	#define DRV_NAME "advantechwdt"
1d747be6 WVS	47	#define PFX DRV_NAME ": "
1da177e4	48	#define WATCHDOG_NAME "Advantech WDT"
1da177e4 LT	49	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
	50
	51	static unsigned long advwdt_is_open;
	52	static char adv_expect_close;
	53
	54	/*
	55	* You must set these - there is no sane way to probe for this board.
	56	*
	57	* To enable or restart, write the timeout value in seconds (1 to 63)
	58	* to I/O port wdt_start. To disable, read I/O port wdt_stop.
	59	* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
	60	* check your manual (at least the PCA-6159 seems to be different -
	61	* the manual says wdt_stop is 0x43, not 0x443).
	62	* (0x43 is also a write-only control register for the 8254 timer!)
	63	*/
	64
	65	static int wdt_stop = 0x443;
	66	module_param(wdt_stop, int, 0);
	67	MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
	68
	69	static int wdt_start = 0x443;
	70	module_param(wdt_start, int, 0);
	71	MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
	72
	73	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	74	module_param(timeout, int, 0);
	75	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
	76
4bfdf378	77	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	78	module_param(nowayout, int, 0);
1d747be6	79	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	80
1da177e4 LT	81	/*
1d747be6	82	* Watchdog Operations
1da177e4 LT	83	*/
	84
	85	static void
	86	advwdt_ping(void)
	87	{
	88	/* Write a watchdog value */
	89	outb_p(timeout, wdt_start);
	90	}
	91
	92	static void
	93	advwdt_disable(void)
	94	{
	95	inb_p(wdt_stop);
	96	}
	97
0349a363 WVS	98	static int
	99	advwdt_set_heartbeat(int t)
	100	{
	101	if ((t < 1) \|\| (t > 63))
	102	return -EINVAL;
	103
	104	timeout = t;
	105	return 0;
	106	}
	107
1d747be6 WVS	108	/*
	109	* /dev/watchdog handling
	110	*/
	111
1da177e4 LT	112	static ssize_t
	113	advwdt_write(struct file file, const char __user buf, size_t count, loff_t *ppos)
	114	{
	115	if (count) {
	116	if (!nowayout) {
	117	size_t i;
	118
	119	adv_expect_close = 0;
	120
	121	for (i = 0; i != count; i++) {
	122	char c;
	123	if (get_user(c, buf+i))
	124	return -EFAULT;
	125	if (c == 'V')
	126	adv_expect_close = 42;
	127	}
	128	}
	129	advwdt_ping();
	130	}
	131	return count;
	132	}
	133
	134	static int
	135	advwdt_ioctl(struct inode inode, struct file file, unsigned int cmd,
	136	unsigned long arg)
	137	{
	138	int new_timeout;
	139	void __user argp = (void __user )arg;
	140	int __user *p = argp;
	141	static struct watchdog_info ident = {
	142	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	143	.firmware_version = 1,
1d747be6	144	.identity = WATCHDOG_NAME,
1da177e4 LT	145	};
	146
	147	switch (cmd) {
	148	case WDIOC_GETSUPPORT:
	149	if (copy_to_user(argp, &ident, sizeof(ident)))
	150	return -EFAULT;
	151	break;
	152
	153	case WDIOC_GETSTATUS:
	154	case WDIOC_GETBOOTSTATUS:
	155	return put_user(0, p);
	156
	157	case WDIOC_KEEPALIVE:
	158	advwdt_ping();
	159	break;
	160
	161	case WDIOC_SETTIMEOUT:
	162	if (get_user(new_timeout, p))
	163	return -EFAULT;
0349a363	164	if (advwdt_set_heartbeat(new_timeout))
1da177e4	165	return -EINVAL;
1da177e4 LT	166	advwdt_ping();
	167	/* Fall */
	168
	169	case WDIOC_GETTIMEOUT:
	170	return put_user(timeout, p);
	171
	172	case WDIOC_SETOPTIONS:
	173	{
	174	int options, retval = -EINVAL;
	175
	176	if (get_user(options, p))
	177	return -EFAULT;
	178
	179	if (options & WDIOS_DISABLECARD) {
	180	advwdt_disable();
	181	retval = 0;
	182	}
	183
	184	if (options & WDIOS_ENABLECARD) {
	185	advwdt_ping();
	186	retval = 0;
	187	}
	188
	189	return retval;
	190	}
	191
	192	default:
795b89d2	193	return -ENOTTY;
1da177e4 LT	194	}
	195	return 0;
	196	}
	197
	198	static int
	199	advwdt_open(struct inode inode, struct file file)
	200	{
	201	if (test_and_set_bit(0, &advwdt_is_open))
	202	return -EBUSY;
	203	/*
	204	* Activate
	205	*/
	206
	207	advwdt_ping();
	208	return nonseekable_open(inode, file);
	209	}
	210
	211	static int
	212	advwdt_close(struct inode inode, struct file file)
	213	{
	214	if (adv_expect_close == 42) {
	215	advwdt_disable();
	216	} else {
	217	printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
	218	advwdt_ping();
	219	}
	220	clear_bit(0, &advwdt_is_open);
	221	adv_expect_close = 0;
	222	return 0;
	223	}
	224
	225	/*
	226	* Notifier for system down
	227	*/
	228
	229	static int
	230	advwdt_notify_sys(struct notifier_block *this, unsigned long code,
	231	void *unused)
	232	{
	233	if (code == SYS_DOWN \|\| code == SYS_HALT) {
	234	/* Turn the WDT off */
	235	advwdt_disable();
	236	}
	237	return NOTIFY_DONE;
	238	}
	239
	240	/*
	241	* Kernel Interfaces
	242	*/
	243
62322d25	244	static const struct file_operations advwdt_fops = {
1da177e4 LT	245	.owner = THIS_MODULE,
	246	.llseek = no_llseek,
	247	.write = advwdt_write,
	248	.ioctl = advwdt_ioctl,
	249	.open = advwdt_open,
	250	.release = advwdt_close,
	251	};
	252
	253	static struct miscdevice advwdt_miscdev = {
1d747be6 WVS	254	.minor = WATCHDOG_MINOR,
	255	.name = "watchdog",
	256	.fops = &advwdt_fops,
1da177e4 LT	257	};
	258
	259	/*
	260	* The WDT needs to learn about soft shutdowns in order to
	261	* turn the timebomb registers off.
	262	*/
	263
	264	static struct notifier_block advwdt_notifier = {
	265	.notifier_call = advwdt_notify_sys,
	266	};
	267
1d747be6 WVS	268	/*
	269	* Init & exit routines
	270	*/
	271
1da177e4 LT	272	static int __init
	273	advwdt_init(void)
	274	{
	275	int ret;
	276
	277	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
	278
1da177e4 LT	279	if (wdt_stop != wdt_start) {
	280	if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
	281	printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
	282	wdt_stop);
	283	ret = -EIO;
	284	goto out;
	285	}
	286	}
	287
	288	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
	289	printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
	290	wdt_start);
	291	ret = -EIO;
	292	goto unreg_stop;
	293	}
	294
0349a363 WVS	295	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	296	if (advwdt_set_heartbeat(timeout)) {
	297	advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
	298	printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
	299	timeout);
	300	}
	301
1da177e4 LT	302	ret = register_reboot_notifier(&advwdt_notifier);
	303	if (ret != 0) {
	304	printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
	305	ret);
	306	goto unreg_regions;
	307	}
	308
	309	ret = misc_register(&advwdt_miscdev);
	310	if (ret != 0) {
	311	printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
	312	WATCHDOG_MINOR, ret);
	313	goto unreg_reboot;
	314	}
	315
	316	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
	317	timeout, nowayout);
	318
	319	out:
	320	return ret;
	321	unreg_reboot:
	322	unregister_reboot_notifier(&advwdt_notifier);
	323	unreg_regions:
	324	release_region(wdt_start, 1);
	325	unreg_stop:
	326	if (wdt_stop != wdt_start)
	327	release_region(wdt_stop, 1);
	328	goto out;
	329	}
	330
	331	static void __exit
	332	advwdt_exit(void)
	333	{
	334	misc_deregister(&advwdt_miscdev);
	335	unregister_reboot_notifier(&advwdt_notifier);
1d747be6	336	release_region(wdt_start,1);
1da177e4 LT	337	if(wdt_stop != wdt_start)
1da177e4 LT	338	release_region(wdt_stop,1);
1da177e4 LT	339	}
	340
	341	module_init(advwdt_init);
	342	module_exit(advwdt_exit);
	343
	344	MODULE_LICENSE("GPL");
	345	MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
	346	MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
	347	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);