[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / 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@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>
 *
 *	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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/platform_device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/uaccess.h>


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

/* the watchdog platform device */
static struct platform_device *advwdt_platform_device;
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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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 long advwdt_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 = 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_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;
	}
	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);
	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 {
		pr_crit("Unexpected close, not stopping watchdog!\n");
		advwdt_ping();
	}
	clear_bit(0, &advwdt_is_open);
	adv_expect_close = 0;
	return 0;
}

/*
 *	Kernel Interfaces
 */

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

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

/*
 *	Init & exit routines
 */

static int advwdt_probe(struct platform_device *dev)
{
	int ret;

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

	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
		pr_err("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);
		pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
	}

	ret = misc_register(&advwdt_miscdev);
	if (ret != 0) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		goto unreg_regions;
	}
	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);
out:
	return ret;
unreg_regions:
	release_region(wdt_start, 1);
unreg_stop:
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
	goto out;
}

static int advwdt_remove(struct platform_device *dev)
{
	misc_deregister(&advwdt_miscdev);
	release_region(wdt_start, 1);
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);

	return 0;
}

static void advwdt_shutdown(struct platform_device *dev)
{
	/* Turn the WDT off if we have a soft shutdown */
	advwdt_disable();
}

static struct platform_driver advwdt_driver = {
	.probe		= advwdt_probe,
	.remove		= advwdt_remove,
	.shutdown	= advwdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= DRV_NAME,
	},
};

static int __init advwdt_init(void)
{
	int err;

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

	err = platform_driver_register(&advwdt_driver);
	if (err)
		return err;

	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
								-1, NULL, 0);
	if (IS_ERR(advwdt_platform_device)) {
		err = PTR_ERR(advwdt_platform_device);
		goto unreg_platform_driver;
	}

	return 0;

unreg_platform_driver:
	platform_driver_unregister(&advwdt_driver);
	return err;
}

static void __exit advwdt_exit(void)
{
	platform_device_unregister(advwdt_platform_device);
	platform_driver_unregister(&advwdt_driver);
	pr_info("Watchdog Module Unloaded\n");
}

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	*
29fa0586 AC	9	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
29fa0586 AC	10	* All Rights Reserved.
1da177e4 LT	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	*
29fa0586	21	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 LT	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
27c766aa JP	31	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	32
1da177e4 LT	33	#include <linux/module.h>
	34	#include <linux/moduleparam.h>
	35	#include <linux/types.h>
	36	#include <linux/miscdevice.h>
	37	#include <linux/watchdog.h>
	38	#include <linux/fs.h>
	39	#include <linux/ioport.h>
c2bd11c7	40	#include <linux/platform_device.h>
1da177e4	41	#include <linux/init.h>
089ab079 WVS	42	#include <linux/io.h>
089ab079 WVS	43	#include <linux/uaccess.h>
1da177e4	44
1da177e4	45
1d747be6	46	#define DRV_NAME "advantechwdt"
1da177e4	47	#define WATCHDOG_NAME "Advantech WDT"
1da177e4 LT	48	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
1da177e4 LT	49
7944d3a5 WVS	50	/* the watchdog platform device */
7944d3a5 WVS	51	static struct platform_device *advwdt_platform_device;
1da177e4 LT	52	static unsigned long advwdt_is_open;
	53	static char adv_expect_close;
	54
	55	/*
	56	* You must set these - there is no sane way to probe for this board.
	57	*
	58	* To enable or restart, write the timeout value in seconds (1 to 63)
	59	* to I/O port wdt_start. To disable, read I/O port wdt_stop.
	60	* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
	61	* check your manual (at least the PCA-6159 seems to be different -
	62	* the manual says wdt_stop is 0x43, not 0x443).
	63	* (0x43 is also a write-only control register for the 8254 timer!)
	64	*/
	65
	66	static int wdt_stop = 0x443;
	67	module_param(wdt_stop, int, 0);
	68	MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
	69
	70	static int wdt_start = 0x443;
	71	module_param(wdt_start, int, 0);
	72	MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
	73
	74	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	75	module_param(timeout, int, 0);
b6b4d9b8 AC	76	MODULE_PARM_DESC(timeout,
	77	"Watchdog timeout in seconds. 1<= timeout <=63, default="
	78	__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4	79
86a1e189 WVS	80	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	81	module_param(nowayout, bool, 0);
b6b4d9b8 AC	82	MODULE_PARM_DESC(nowayout,
	83	"Watchdog cannot be stopped once started (default="
	84	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	85
1da177e4 LT	86	/*
1d747be6	87	* Watchdog Operations
1da177e4 LT	88	*/
1da177e4 LT	89
b6b4d9b8	90	static void advwdt_ping(void)
1da177e4 LT	91	{
	92	/* Write a watchdog value */
	93	outb_p(timeout, wdt_start);
	94	}
	95
b6b4d9b8	96	static void advwdt_disable(void)
1da177e4 LT	97	{
	98	inb_p(wdt_stop);
	99	}
	100
b6b4d9b8	101	static int advwdt_set_heartbeat(int t)
0349a363	102	{
b6b4d9b8	103	if (t < 1 \|\| t > 63)
0349a363	104	return -EINVAL;
0349a363 WVS	105	timeout = t;
	106	return 0;
	107	}
	108
1d747be6 WVS	109	/*
	110	* /dev/watchdog handling
	111	*/
	112
b6b4d9b8 AC	113	static ssize_t advwdt_write(struct file file, const char __user buf,
b6b4d9b8 AC	114	size_t count, loff_t *ppos)
1da177e4 LT	115	{
	116	if (count) {
	117	if (!nowayout) {
	118	size_t i;
	119
	120	adv_expect_close = 0;
	121
	122	for (i = 0; i != count; i++) {
	123	char c;
7944d3a5	124	if (get_user(c, buf + i))
1da177e4 LT	125	return -EFAULT;
	126	if (c == 'V')
	127	adv_expect_close = 42;
	128	}
	129	}
	130	advwdt_ping();
	131	}
	132	return count;
	133	}
	134
b6b4d9b8	135	static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	136	{
	137	int new_timeout;
	138	void __user argp = (void __user )arg;
	139	int __user *p = argp;
42747d71	140	static const struct watchdog_info ident = {
143a2e54 WVS	141	.options = WDIOF_KEEPALIVEPING \|
	142	WDIOF_SETTIMEOUT \|
	143	WDIOF_MAGICCLOSE,
1da177e4	144	.firmware_version = 1,
1d747be6	145	.identity = WATCHDOG_NAME,
1da177e4 LT	146	};
	147
	148	switch (cmd) {
	149	case WDIOC_GETSUPPORT:
b6b4d9b8 AC	150	if (copy_to_user(argp, &ident, sizeof(ident)))
	151	return -EFAULT;
	152	break;
1da177e4 LT	153
	154	case WDIOC_GETSTATUS:
	155	case WDIOC_GETBOOTSTATUS:
b6b4d9b8	156	return put_user(0, p);
1da177e4	157
1da177e4 LT	158	case WDIOC_SETOPTIONS:
1da177e4 LT	159	{
b6b4d9b8	160	int options, retval = -EINVAL;
1da177e4	161
b6b4d9b8 AC	162	if (get_user(options, p))
	163	return -EFAULT;
	164	if (options & WDIOS_DISABLECARD) {
	165	advwdt_disable();
	166	retval = 0;
	167	}
	168	if (options & WDIOS_ENABLECARD) {
	169	advwdt_ping();
	170	retval = 0;
	171	}
	172	return retval;
1da177e4	173	}
0c06090c WVS	174	case WDIOC_KEEPALIVE:
	175	advwdt_ping();
	176	break;
	177
	178	case WDIOC_SETTIMEOUT:
	179	if (get_user(new_timeout, p))
	180	return -EFAULT;
	181	if (advwdt_set_heartbeat(new_timeout))
	182	return -EINVAL;
	183	advwdt_ping();
	184	/* Fall */
	185	case WDIOC_GETTIMEOUT:
	186	return put_user(timeout, p);
1da177e4	187	default:
b6b4d9b8	188	return -ENOTTY;
1da177e4 LT	189	}
	190	return 0;
	191	}
	192
b6b4d9b8	193	static int advwdt_open(struct inode inode, struct file file)
1da177e4 LT	194	{
	195	if (test_and_set_bit(0, &advwdt_is_open))
	196	return -EBUSY;
	197	/*
	198	* Activate
	199	*/
	200
	201	advwdt_ping();
	202	return nonseekable_open(inode, file);
	203	}
	204
7944d3a5	205	static int advwdt_close(struct inode inode, struct file file)
1da177e4 LT	206	{
	207	if (adv_expect_close == 42) {
	208	advwdt_disable();
	209	} else {
27c766aa	210	pr_crit("Unexpected close, not stopping watchdog!\n");
1da177e4 LT	211	advwdt_ping();
	212	}
	213	clear_bit(0, &advwdt_is_open);
	214	adv_expect_close = 0;
	215	return 0;
	216	}
	217
1da177e4 LT	218	/*
	219	* Kernel Interfaces
	220	*/
	221
62322d25	222	static const struct file_operations advwdt_fops = {
1da177e4 LT	223	.owner = THIS_MODULE,
	224	.llseek = no_llseek,
	225	.write = advwdt_write,
b6b4d9b8	226	.unlocked_ioctl = advwdt_ioctl,
1da177e4 LT	227	.open = advwdt_open,
	228	.release = advwdt_close,
	229	};
	230
	231	static struct miscdevice advwdt_miscdev = {
1d747be6 WVS	232	.minor = WATCHDOG_MINOR,
	233	.name = "watchdog",
	234	.fops = &advwdt_fops,
1da177e4 LT	235	};
1da177e4 LT	236
1d747be6 WVS	237	/*
	238	* Init & exit routines
	239	*/
	240
2d991a16	241	static int advwdt_probe(struct platform_device *dev)
1da177e4 LT	242	{
	243	int ret;
	244
1da177e4 LT	245	if (wdt_stop != wdt_start) {
1da177e4 LT	246	if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
27c766aa JP	247	pr_err("I/O address 0x%04x already in use\n",
27c766aa JP	248	wdt_stop);
1da177e4 LT	249	ret = -EIO;
	250	goto out;
	251	}
	252	}
	253
	254	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
27c766aa	255	pr_err("I/O address 0x%04x already in use\n", wdt_start);
1da177e4 LT	256	ret = -EIO;
	257	goto unreg_stop;
	258	}
	259
143a2e54 WVS	260	/* Check that the heartbeat value is within it's range ;
143a2e54 WVS	261	* if not reset to the default */
0349a363 WVS	262	if (advwdt_set_heartbeat(timeout)) {
0349a363 WVS	263	advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
27c766aa	264	pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
0349a363 WVS	265	}
0349a363 WVS	266
1da177e4 LT	267	ret = misc_register(&advwdt_miscdev);
1da177e4 LT	268	if (ret != 0) {
27c766aa JP	269	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	270	WATCHDOG_MINOR, ret);
2e9c9cf4	271	goto unreg_regions;
1da177e4	272	}
27c766aa	273	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4	274	timeout, nowayout);
1da177e4 LT	275	out:
1da177e4 LT	276	return ret;
1da177e4 LT	277	unreg_regions:
	278	release_region(wdt_start, 1);
	279	unreg_stop:
	280	if (wdt_stop != wdt_start)
	281	release_region(wdt_stop, 1);
	282	goto out;
	283	}
	284
4b12b896	285	static int advwdt_remove(struct platform_device *dev)
1da177e4 LT	286	{
1da177e4 LT	287	misc_deregister(&advwdt_miscdev);
7944d3a5 WVS	288	release_region(wdt_start, 1);
	289	if (wdt_stop != wdt_start)
	290	release_region(wdt_stop, 1);
c2bd11c7 WVS	291
	292	return 0;
	293	}
	294
b6b4d9b8	295	static void advwdt_shutdown(struct platform_device *dev)
2e9c9cf4 WVS	296	{
	297	/* Turn the WDT off if we have a soft shutdown */
	298	advwdt_disable();
	299	}
	300
c2bd11c7 WVS	301	static struct platform_driver advwdt_driver = {
c2bd11c7 WVS	302	.probe = advwdt_probe,
82268714	303	.remove = advwdt_remove,
2e9c9cf4	304	.shutdown = advwdt_shutdown,
c2bd11c7 WVS	305	.driver = {
	306	.owner = THIS_MODULE,
	307	.name = DRV_NAME,
	308	},
	309	};
	310
b6b4d9b8	311	static int __init advwdt_init(void)
c2bd11c7 WVS	312	{
	313	int err;
	314
27c766aa	315	pr_info("WDT driver for Advantech single board computer initialising\n");
c2bd11c7 WVS	316
	317	err = platform_driver_register(&advwdt_driver);
	318	if (err)
	319	return err;
	320
b6b4d9b8 AC	321	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
b6b4d9b8 AC	322	-1, NULL, 0);
c2bd11c7 WVS	323	if (IS_ERR(advwdt_platform_device)) {
	324	err = PTR_ERR(advwdt_platform_device);
	325	goto unreg_platform_driver;
	326	}
	327
	328	return 0;
	329
	330	unreg_platform_driver:
	331	platform_driver_unregister(&advwdt_driver);
	332	return err;
	333	}
	334
b6b4d9b8	335	static void __exit advwdt_exit(void)
c2bd11c7 WVS	336	{
	337	platform_device_unregister(advwdt_platform_device);
	338	platform_driver_unregister(&advwdt_driver);
27c766aa	339	pr_info("Watchdog Module Unloaded\n");
1da177e4 LT	340	}
	341
	342	module_init(advwdt_init);
	343	module_exit(advwdt_exit);
	344
	345	MODULE_LICENSE("GPL");
	346	MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
	347	MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
	348	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);