[net-next-2.6.git] / drivers / watchdog / sbc_fitpc2_wdt.c

/*
 * Watchdog driver for SBC-FITPC2 board
 *
 * Author: Denis Turischev <denis@compulab.co.il>
 *
 * Adapted from the IXP2000 watchdog driver by Deepak Saxena.
 *
 * This file is licensed under  the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt

#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/dmi.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <asm/system.h>

static int nowayout = WATCHDOG_NOWAYOUT;
static unsigned int margin = 60;	/* (secs) Default is 1 minute */
static unsigned long wdt_status;
static DEFINE_MUTEX(wdt_lock);

#define WDT_IN_USE		0
#define WDT_OK_TO_CLOSE		1

#define COMMAND_PORT		0x4c
#define DATA_PORT		0x48

#define IFACE_ON_COMMAND	1
#define REBOOT_COMMAND		2

#define WATCHDOG_NAME 		"SBC-FITPC2 Watchdog"

static void wdt_send_data(unsigned char command, unsigned char data)
{
	outb(data, DATA_PORT);
	msleep(200);
	outb(command, COMMAND_PORT);
	msleep(100);
}

static void wdt_enable(void)
{
	mutex_lock(&wdt_lock);
	wdt_send_data(IFACE_ON_COMMAND, 1);
	wdt_send_data(REBOOT_COMMAND, margin);
	mutex_unlock(&wdt_lock);
}

static void wdt_disable(void)
{
	mutex_lock(&wdt_lock);
	wdt_send_data(IFACE_ON_COMMAND, 0);
	wdt_send_data(REBOOT_COMMAND, 0);
	mutex_unlock(&wdt_lock);
}

static int fitpc2_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
		return -EBUSY;

	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

	wdt_enable();

	return nonseekable_open(inode, file);
}

static ssize_t fitpc2_wdt_write(struct file *file, const char *data,
						size_t len, loff_t *ppos)
{
	size_t i;

	if (!len)
		return 0;

	if (nowayout) {
		len = 0;
		goto out;
	}

	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

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

		if (get_user(c, data + i))
			return -EFAULT;

		if (c == 'V')
			set_bit(WDT_OK_TO_CLOSE, &wdt_status);
	}

out:
	wdt_enable();

	return len;
}


static const struct watchdog_info ident = {
	.options	= WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
				WDIOF_KEEPALIVEPING,
	.identity	= WATCHDOG_NAME,
};


static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int ret = -ENOTTY;
	int time;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = copy_to_user((struct watchdog_info *)arg, &ident,
				   sizeof(ident)) ? -EFAULT : 0;
		break;

	case WDIOC_GETSTATUS:
		ret = put_user(0, (int *)arg);
		break;

	case WDIOC_GETBOOTSTATUS:
		ret = put_user(0, (int *)arg);
		break;

	case WDIOC_KEEPALIVE:
		wdt_enable();
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(time, (int *)arg);
		if (ret)
			break;

		if (time < 31 || time > 255) {
			ret = -EINVAL;
			break;
		}

		margin = time;
		wdt_enable();
		/* Fall through */

	case WDIOC_GETTIMEOUT:
		ret = put_user(margin, (int *)arg);
		break;
	}

	return ret;
}

static int fitpc2_wdt_release(struct inode *inode, struct file *file)
{
	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
		wdt_disable();
		pr_info("Device disabled\n");
	} else {
		pr_warning("Device closed unexpectedly -"
			" timer will not stop\n");
		wdt_enable();
	}

	clear_bit(WDT_IN_USE, &wdt_status);
	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

	return 0;
}


static const struct file_operations fitpc2_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= fitpc2_wdt_write,
	.unlocked_ioctl	= fitpc2_wdt_ioctl,
	.open		= fitpc2_wdt_open,
	.release	= fitpc2_wdt_release,
};

static struct miscdevice fitpc2_wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &fitpc2_wdt_fops,
};

static int __init fitpc2_wdt_init(void)
{
	int err;

	if (!strstr(dmi_get_system_info(DMI_BOARD_NAME), "SBC-FITPC2"))
		return -ENODEV;

	pr_info("%s found\n", dmi_get_system_info(DMI_BOARD_NAME));

	if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) {
		pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT);
		return -EIO;
	}

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

	if (margin < 31 || margin > 255) {
		pr_err("margin must be in range 31 - 255"
		       " seconds, you tried to set %d\n", margin);
		err = -EINVAL;
		goto err_margin;
	}

	err = misc_register(&fitpc2_wdt_miscdev);
	if (err) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
							WATCHDOG_MINOR, err);
		goto err_margin;
	}

	return 0;

err_margin:
	release_region(DATA_PORT, 1);
err_data_port:
	release_region(COMMAND_PORT, 1);

	return err;
}

static void __exit fitpc2_wdt_exit(void)
{
	misc_deregister(&fitpc2_wdt_miscdev);
	release_region(DATA_PORT, 1);
	release_region(COMMAND_PORT, 1);
}

module_init(fitpc2_wdt_init);
module_exit(fitpc2_wdt_exit);

MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
MODULE_DESCRIPTION("SBC-FITPC2 Watchdog");

module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
3a5f9000 DT	1	/*
	2	* Watchdog driver for SBC-FITPC2 board
	3	*
	4	* Author: Denis Turischev <denis@compulab.co.il>
	5	*
	6	* Adapted from the IXP2000 watchdog driver by Deepak Saxena.
	7	*
	8	* This file is licensed under the terms of the GNU General Public
	9	* License version 2. This program is licensed "as is" without any
	10	* warranty of any kind, whether express or implied.
	11	*/
	12
	13	#define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt
	14
	15	#include <linux/module.h>
	16	#include <linux/types.h>
	17	#include <linux/miscdevice.h>
	18	#include <linux/watchdog.h>
	19	#include <linux/ioport.h>
	20	#include <linux/delay.h>
	21	#include <linux/fs.h>
	22	#include <linux/init.h>
	23	#include <linux/moduleparam.h>
	24	#include <linux/dmi.h>
	25	#include <linux/io.h>
	26	#include <linux/uaccess.h>
	27
	28	#include <asm/system.h>
	29
	30	static int nowayout = WATCHDOG_NOWAYOUT;
	31	static unsigned int margin = 60; /* (secs) Default is 1 minute */
	32	static unsigned long wdt_status;
322af98c	33	static DEFINE_MUTEX(wdt_lock);
3a5f9000 DT	34
	35	#define WDT_IN_USE 0
	36	#define WDT_OK_TO_CLOSE 1
	37
	38	#define COMMAND_PORT 0x4c
	39	#define DATA_PORT 0x48
	40
	41	#define IFACE_ON_COMMAND 1
	42	#define REBOOT_COMMAND 2
	43
	44	#define WATCHDOG_NAME "SBC-FITPC2 Watchdog"
	45
	46	static void wdt_send_data(unsigned char command, unsigned char data)
	47	{
3a5f9000	48	outb(data, DATA_PORT);
ef39a1bf	49	msleep(200);
fcf1dd7e DT	50	outb(command, COMMAND_PORT);
fcf1dd7e DT	51	msleep(100);
3a5f9000 DT	52	}
	53
	54	static void wdt_enable(void)
	55	{
322af98c	56	mutex_lock(&wdt_lock);
3a5f9000 DT	57	wdt_send_data(IFACE_ON_COMMAND, 1);
3a5f9000 DT	58	wdt_send_data(REBOOT_COMMAND, margin);
322af98c	59	mutex_unlock(&wdt_lock);
3a5f9000 DT	60	}
	61
	62	static void wdt_disable(void)
	63	{
322af98c	64	mutex_lock(&wdt_lock);
3a5f9000 DT	65	wdt_send_data(IFACE_ON_COMMAND, 0);
3a5f9000 DT	66	wdt_send_data(REBOOT_COMMAND, 0);
322af98c	67	mutex_unlock(&wdt_lock);
3a5f9000 DT	68	}
	69
	70	static int fitpc2_wdt_open(struct inode inode, struct file file)
	71	{
	72	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
	73	return -EBUSY;
	74
	75	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	76
	77	wdt_enable();
	78
	79	return nonseekable_open(inode, file);
	80	}
	81
	82	static ssize_t fitpc2_wdt_write(struct file file, const char data,
	83	size_t len, loff_t *ppos)
	84	{
	85	size_t i;
	86
	87	if (!len)
	88	return 0;
	89
	90	if (nowayout) {
	91	len = 0;
	92	goto out;
	93	}
	94
	95	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	96
	97	for (i = 0; i != len; i++) {
	98	char c;
	99
	100	if (get_user(c, data + i))
	101	return -EFAULT;
	102
	103	if (c == 'V')
	104	set_bit(WDT_OK_TO_CLOSE, &wdt_status);
	105	}
	106
	107	out:
	108	wdt_enable();
	109
	110	return len;
	111	}
	112
	113
42747d71	114	static const struct watchdog_info ident = {
3a5f9000 DT	115	.options = WDIOF_MAGICCLOSE \| WDIOF_SETTIMEOUT \|
	116	WDIOF_KEEPALIVEPING,
	117	.identity = WATCHDOG_NAME,
	118	};
	119
	120
	121	static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
	122	unsigned long arg)
	123	{
	124	int ret = -ENOTTY;
	125	int time;
	126
	127	switch (cmd) {
	128	case WDIOC_GETSUPPORT:
	129	ret = copy_to_user((struct watchdog_info *)arg, &ident,
	130	sizeof(ident)) ? -EFAULT : 0;
	131	break;
	132
	133	case WDIOC_GETSTATUS:
	134	ret = put_user(0, (int *)arg);
	135	break;
	136
	137	case WDIOC_GETBOOTSTATUS:
	138	ret = put_user(0, (int *)arg);
	139	break;
	140
	141	case WDIOC_KEEPALIVE:
	142	wdt_enable();
	143	ret = 0;
	144	break;
	145
	146	case WDIOC_SETTIMEOUT:
	147	ret = get_user(time, (int *)arg);
	148	if (ret)
	149	break;
	150
	151	if (time < 31 \|\| time > 255) {
	152	ret = -EINVAL;
	153	break;
	154	}
	155
	156	margin = time;
	157	wdt_enable();
	158	/* Fall through */
	159
	160	case WDIOC_GETTIMEOUT:
	161	ret = put_user(margin, (int *)arg);
	162	break;
	163	}
	164
	165	return ret;
	166	}
	167
	168	static int fitpc2_wdt_release(struct inode inode, struct file file)
	169	{
	170	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
	171	wdt_disable();
	172	pr_info("Device disabled\n");
	173	} else {
	174	pr_warning("Device closed unexpectedly -"
	175	" timer will not stop\n");
	176	wdt_enable();
	177	}
	178
179	clear_bit(WDT_IN_USE, &wdt_status);
180	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
181
182	return 0;
183	}
184
185
186	static const struct file_operations fitpc2_wdt_fops = {
187	.owner = THIS_MODULE,
188	.llseek = no_llseek,
189	.write = fitpc2_wdt_write,
190	.unlocked_ioctl = fitpc2_wdt_ioctl,
191	.open = fitpc2_wdt_open,
192	.release = fitpc2_wdt_release,
193	};
194
195	static struct miscdevice fitpc2_wdt_miscdev = {
196	.minor = WATCHDOG_MINOR,
197	.name = "watchdog",
198	.fops = &fitpc2_wdt_fops,
199	};
200
201	static int __init fitpc2_wdt_init(void)
202	{
203	int err;
204
ef39a1bf	205	if (!strstr(dmi_get_system_info(DMI_BOARD_NAME), "SBC-FITPC2"))
3a5f9000	206	return -ENODEV;
ef39a1bf DT	207
ef39a1bf DT	208	pr_info("%s found\n", dmi_get_system_info(DMI_BOARD_NAME));
3a5f9000 DT	209
	210	if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) {
	211	pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT);
	212	return -EIO;
	213	}
	214
	215	if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) {
	216	pr_err("I/O address 0x%04x already in use\n", DATA_PORT);
	217	err = -EIO;
	218	goto err_data_port;
	219	}
	220
	221	if (margin < 31 \|\| margin > 255) {
	222	pr_err("margin must be in range 31 - 255"
	223	" seconds, you tried to set %d\n", margin);
	224	err = -EINVAL;
	225	goto err_margin;
	226	}
	227
	228	err = misc_register(&fitpc2_wdt_miscdev);
1efd374d	229	if (err) {
3a5f9000 DT	230	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	231	WATCHDOG_MINOR, err);
	232	goto err_margin;
	233	}
	234
	235	return 0;
	236
	237	err_margin:
	238	release_region(DATA_PORT, 1);
	239	err_data_port:
	240	release_region(COMMAND_PORT, 1);
	241
	242	return err;
	243	}
	244
	245	static void __exit fitpc2_wdt_exit(void)
	246	{
	247	misc_deregister(&fitpc2_wdt_miscdev);
	248	release_region(DATA_PORT, 1);
	249	release_region(COMMAND_PORT, 1);
	250	}
	251
	252	module_init(fitpc2_wdt_init);
	253	module_exit(fitpc2_wdt_exit);
	254
	255	MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
	256	MODULE_DESCRIPTION("SBC-FITPC2 Watchdog");
	257
	258	module_param(margin, int, 0);
	259	MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
	260
	261	module_param(nowayout, int, 0);
	262	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
	263
	264	MODULE_LICENSE("GPL");
	265	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	266