[deliverable/linux.git] / drivers / char / watchdog / mixcomwd.c

/*
 * MixCom Watchdog: A Simple Hardware Watchdog Device
 * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
 *
 * Author: Gergely Madarasz <gorgo@itc.hu>
 *
 * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
 *
 * 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.
 *
 * Version 0.1 (99/04/15):
 *		- first version
 *
 * Version 0.2 (99/06/16):
 *		- added kernel timer watchdog ping after close
 *		  since the hardware does not support watchdog shutdown
 *
 * Version 0.3 (99/06/21):
 *		- added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
 *
 * Version 0.3.1 (99/06/22):
 *		- allow module removal while internal timer is active,
 *		  print warning about probable reset
 *
 * Version 0.4 (99/11/15):
 *		- support for one more type board
 *
 * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
 *		- added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *
 * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
 *		- make mixcomwd_opened unsigned,
 *		  removed lock_kernel/unlock_kernel from mixcomwd_release,
 *		  modified ioctl a bit to conform to API
 *
 */

#define VERSION "0.6"
#define WATCHDOG_NAME "mixcomwd"
#define PFX WATCHDOG_NAME ": "

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/*
 * We have two types of cards that can be probed:
 * 1) The Mixcom cards: these cards can be found at addresses
 *    0x180, 0x280, 0x380 with an additional offset of 0xc10.
 *    (Or 0xd90, 0xe90, 0xf90).
 * 2) The FlashCOM cards: these cards can be set up at
 *    0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
 *    (Or 0x304 -> 0x37c in 0x8 jumps).
 *    Each card has it's own ID.
 */
#define MIXCOM_ID 0x11
#define FLASHCOM_ID 0x18
static struct {
	int ioport;
	int id;
} mixcomwd_io_info[] __devinitdata = {
	/* The Mixcom cards */
	{0x0d90, MIXCOM_ID},
	{0x0e90, MIXCOM_ID},
	{0x0f90, MIXCOM_ID},
	/* The FlashCOM cards */
	{0x0304, FLASHCOM_ID},
	{0x030c, FLASHCOM_ID},
	{0x0314, FLASHCOM_ID},
	{0x031c, FLASHCOM_ID},
	{0x0324, FLASHCOM_ID},
	{0x032c, FLASHCOM_ID},
	{0x0334, FLASHCOM_ID},
	{0x033c, FLASHCOM_ID},
	{0x0344, FLASHCOM_ID},
	{0x034c, FLASHCOM_ID},
	{0x0354, FLASHCOM_ID},
	{0x035c, FLASHCOM_ID},
	{0x0364, FLASHCOM_ID},
	{0x036c, FLASHCOM_ID},
	{0x0374, FLASHCOM_ID},
	{0x037c, FLASHCOM_ID},
	/* The end of the list */
	{0x0000, 0},
};

static void mixcomwd_timerfun(unsigned long d);

static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */

static int watchdog_port;
static int mixcomwd_timer_alive;
static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
static char expect_close;

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) ")");

static void mixcomwd_ping(void)
{
	outb_p(55,watchdog_port);
	return;
}

static void mixcomwd_timerfun(unsigned long d)
{
	mixcomwd_ping();

	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
}

/*
 *	Allow only one person to hold it open
 */

static int mixcomwd_open(struct inode *inode, struct file *file)
{
	if(test_and_set_bit(0,&mixcomwd_opened)) {
		return -EBUSY;
	}
	mixcomwd_ping();

	if (nowayout) {
		/*
		 * fops_get() code via open() has already done
		 * a try_module_get() so it is safe to do the
		 * __module_get().
		 */
		__module_get(THIS_MODULE);
	} else {
		if(mixcomwd_timer_alive) {
			del_timer(&mixcomwd_timer);
			mixcomwd_timer_alive=0;
		}
	}
	return nonseekable_open(inode, file);
}

static int mixcomwd_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		if(mixcomwd_timer_alive) {
			printk(KERN_ERR PFX "release called while internal timer alive");
			return -EBUSY;
		}
		mixcomwd_timer_alive=1;
		mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
	} else {
		printk(KERN_CRIT PFX "WDT device closed unexpectedly.  WDT will not stop!\n");
	}

	clear_bit(0,&mixcomwd_opened);
	expect_close=0;
	return 0;
}


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

			/* In case it was set long ago */
			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;
			}
		}
		mixcomwd_ping();
	}
	return len;
}

static int mixcomwd_ioctl(struct inode *inode, struct file *file,
	unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int status;
	static struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = "MixCOM watchdog",
	};

	switch(cmd)
	{
		case WDIOC_GETSTATUS:
			status=mixcomwd_opened;
			if (!nowayout) {
				status|=mixcomwd_timer_alive;
			}
			if (copy_to_user(p, &status, sizeof(int))) {
				return -EFAULT;
			}
			break;
		case WDIOC_GETSUPPORT:
			if (copy_to_user(argp, &ident, sizeof(ident))) {
				return -EFAULT;
			}
			break;
		case WDIOC_KEEPALIVE:
			mixcomwd_ping();
			break;
		default:
			return -ENOTTY;
	}
	return 0;
}

static const struct file_operations mixcomwd_fops=
{
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= mixcomwd_write,
	.ioctl		= mixcomwd_ioctl,
	.open		= mixcomwd_open,
	.release	= mixcomwd_release,
};

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

static int __init checkcard(int port, int card_id)
{
	int id;

	if (!request_region(port, 1, "MixCOM watchdog")) {
		return 0;
	}

	id=inb_p(port);
	if (card_id==MIXCOM_ID)
		id &= 0x3f;

	if (id!=card_id) {
		release_region(port, 1);
		return 0;
	}
	return 1;
}

static int __init mixcomwd_init(void)
{
	int i;
	int ret;
	int found=0;

	for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
		if (checkcard(mixcomwd_io_info[i].ioport,
			      mixcomwd_io_info[i].id)) {
			found = 1;
			watchdog_port = mixcomwd_io_info[i].ioport;
		}
	}

	if (!found) {
		printk(KERN_ERR PFX "No card detected, or port not available.\n");
		return -ENODEV;
	}

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

	printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);

	return 0;

error_misc_register_watchdog:
	release_region(watchdog_port, 1);
	watchdog_port = 0x0000;
	return ret;
}

static void __exit mixcomwd_exit(void)
{
	if (!nowayout) {
		if(mixcomwd_timer_alive) {
			printk(KERN_WARNING PFX "I quit now, hardware will"
			       " probably reboot!\n");
			del_timer_sync(&mixcomwd_timer);
			mixcomwd_timer_alive=0;
		}
	}
	misc_deregister(&mixcomwd_miscdev);
	release_region(watchdog_port,1);
}

module_init(mixcomwd_init);
module_exit(mixcomwd_exit);

MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
MODULE_DESCRIPTION("MixCom Watchdog driver");
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* MixCom Watchdog: A Simple Hardware Watchdog Device
	3	* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
	4	*
	5	* Author: Gergely Madarasz <gorgo@itc.hu>
	6	*
	7	* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* Version 0.1 (99/04/15):
	15	* - first version
	16	*
	17	* Version 0.2 (99/06/16):
	18	* - added kernel timer watchdog ping after close
	19	* since the hardware does not support watchdog shutdown
	20	*
	21	* Version 0.3 (99/06/21):
	22	* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
	23	*
	24	* Version 0.3.1 (99/06/22):
	25	* - allow module removal while internal timer is active,
	26	* print warning about probable reset
	27	*
	28	* Version 0.4 (99/11/15):
	29	* - support for one more type board
	30	*
	31	* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
b10958d3 WVS	32	* - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	33	*
	34	* Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
	35	* - make mixcomwd_opened unsigned,
	36	* removed lock_kernel/unlock_kernel from mixcomwd_release,
	37	* modified ioctl a bit to conform to API
1da177e4 LT	38	*
	39	*/
	40
b10958d3	41	#define VERSION "0.6"
1c067318 WVS	42	#define WATCHDOG_NAME "mixcomwd"
1c067318 WVS	43	#define PFX WATCHDOG_NAME ": "
1da177e4 LT	44
	45	#include <linux/module.h>
	46	#include <linux/moduleparam.h>
1da177e4 LT	47	#include <linux/types.h>
	48	#include <linux/miscdevice.h>
	49	#include <linux/ioport.h>
	50	#include <linux/watchdog.h>
	51	#include <linux/fs.h>
	52	#include <linux/reboot.h>
	53	#include <linux/init.h>
4e57b681 TS	54	#include <linux/jiffies.h>
4e57b681 TS	55	#include <linux/timer.h>
1da177e4 LT	56	#include <asm/uaccess.h>
	57	#include <asm/io.h>
	58
63e6e17e WVS	59	/*
	60	* We have two types of cards that can be probed:
	61	* 1) The Mixcom cards: these cards can be found at addresses
	62	* 0x180, 0x280, 0x380 with an additional offset of 0xc10.
	63	* (Or 0xd90, 0xe90, 0xf90).
	64	* 2) The FlashCOM cards: these cards can be set up at
	65	* 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
	66	* (Or 0x304 -> 0x37c in 0x8 jumps).
	67	* Each card has it's own ID.
	68	*/
1da177e4	69	#define MIXCOM_ID 0x11
1da177e4	70	#define FLASHCOM_ID 0x18
21baf3c7 WVS	71	static struct {
	72	int ioport;
	73	int id;
	74	} mixcomwd_io_info[] __devinitdata = {
	75	/* The Mixcom cards */
	76	{0x0d90, MIXCOM_ID},
	77	{0x0e90, MIXCOM_ID},
	78	{0x0f90, MIXCOM_ID},
	79	/* The FlashCOM cards */
	80	{0x0304, FLASHCOM_ID},
	81	{0x030c, FLASHCOM_ID},
	82	{0x0314, FLASHCOM_ID},
	83	{0x031c, FLASHCOM_ID},
	84	{0x0324, FLASHCOM_ID},
	85	{0x032c, FLASHCOM_ID},
	86	{0x0334, FLASHCOM_ID},
	87	{0x033c, FLASHCOM_ID},
	88	{0x0344, FLASHCOM_ID},
	89	{0x034c, FLASHCOM_ID},
	90	{0x0354, FLASHCOM_ID},
	91	{0x035c, FLASHCOM_ID},
	92	{0x0364, FLASHCOM_ID},
	93	{0x036c, FLASHCOM_ID},
	94	{0x0374, FLASHCOM_ID},
	95	{0x037c, FLASHCOM_ID},
	96	/* The end of the list */
	97	{0x0000, 0},
	98	};
1da177e4	99
82eb7c50 JS	100	static void mixcomwd_timerfun(unsigned long d);
82eb7c50 JS	101
1da177e4 LT	102	static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
	103
	104	static int watchdog_port;
	105	static int mixcomwd_timer_alive;
82eb7c50	106	static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
1da177e4 LT	107	static char expect_close;
1da177e4 LT	108
4bfdf378	109	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	110	module_param(nowayout, int, 0);
bffda5c8	111	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	112
	113	static void mixcomwd_ping(void)
	114	{
	115	outb_p(55,watchdog_port);
	116	return;
	117	}
	118
	119	static void mixcomwd_timerfun(unsigned long d)
	120	{
	121	mixcomwd_ping();
	122
82eb7c50	123	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
1da177e4 LT	124	}
	125
	126	/*
	127	* Allow only one person to hold it open
	128	*/
	129
	130	static int mixcomwd_open(struct inode inode, struct file file)
	131	{
	132	if(test_and_set_bit(0,&mixcomwd_opened)) {
	133	return -EBUSY;
	134	}
	135	mixcomwd_ping();
	136
	137	if (nowayout) {
	138	/*
	139	* fops_get() code via open() has already done
	140	* a try_module_get() so it is safe to do the
	141	* __module_get().
	142	*/
	143	__module_get(THIS_MODULE);
	144	} else {
	145	if(mixcomwd_timer_alive) {
	146	del_timer(&mixcomwd_timer);
	147	mixcomwd_timer_alive=0;
	148	}
	149	}
	150	return nonseekable_open(inode, file);
	151	}
	152
	153	static int mixcomwd_release(struct inode inode, struct file file)
	154	{
	155	if (expect_close == 42) {
	156	if(mixcomwd_timer_alive) {
1c067318	157	printk(KERN_ERR PFX "release called while internal timer alive");
1da177e4 LT	158	return -EBUSY;
1da177e4 LT	159	}
1da177e4	160	mixcomwd_timer_alive=1;
82eb7c50	161	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
1da177e4	162	} else {
1c067318	163	printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4 LT	164	}
	165
	166	clear_bit(0,&mixcomwd_opened);
	167	expect_close=0;
	168	return 0;
	169	}
	170
	171
	172	static ssize_t mixcomwd_write(struct file file, const char __user data, size_t len, loff_t *ppos)
	173	{
	174	if(len)
	175	{
	176	if (!nowayout) {
	177	size_t i;
	178
	179	/* In case it was set long ago */
	180	expect_close = 0;
	181
	182	for (i = 0; i != len; i++) {
	183	char c;
	184	if (get_user(c, data + i))
	185	return -EFAULT;
	186	if (c == 'V')
	187	expect_close = 42;
	188	}
	189	}
	190	mixcomwd_ping();
	191	}
	192	return len;
	193	}
	194
	195	static int mixcomwd_ioctl(struct inode inode, struct file file,
	196	unsigned int cmd, unsigned long arg)
	197	{
	198	void __user argp = (void __user )arg;
	199	int __user *p = argp;
	200	int status;
	201	static struct watchdog_info ident = {
	202	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	203	.firmware_version = 1,
	204	.identity = "MixCOM watchdog",
	205	};
	206
	207	switch(cmd)
	208	{
	209	case WDIOC_GETSTATUS:
	210	status=mixcomwd_opened;
	211	if (!nowayout) {
	212	status\|=mixcomwd_timer_alive;
	213	}
	214	if (copy_to_user(p, &status, sizeof(int))) {
	215	return -EFAULT;
	216	}
	217	break;
	218	case WDIOC_GETSUPPORT:
	219	if (copy_to_user(argp, &ident, sizeof(ident))) {
	220	return -EFAULT;
	221	}
	222	break;
	223	case WDIOC_KEEPALIVE:
	224	mixcomwd_ping();
	225	break;
	226	default:
795b89d2	227	return -ENOTTY;
1da177e4 LT	228	}
	229	return 0;
	230	}
	231
62322d25	232	static const struct file_operations mixcomwd_fops=
1da177e4 LT	233	{
	234	.owner = THIS_MODULE,
	235	.llseek = no_llseek,
	236	.write = mixcomwd_write,
	237	.ioctl = mixcomwd_ioctl,
	238	.open = mixcomwd_open,
	239	.release = mixcomwd_release,
	240	};
	241
	242	static struct miscdevice mixcomwd_miscdev=
	243	{
	244	.minor = WATCHDOG_MINOR,
	245	.name = "watchdog",
	246	.fops = &mixcomwd_fops,
	247	};
	248
4194db10	249	static int __init checkcard(int port, int card_id)
1da177e4 LT	250	{
	251	int id;
	252
1da177e4 LT	253	if (!request_region(port, 1, "MixCOM watchdog")) {
	254	return 0;
	255	}
	256
	257	id=inb_p(port);
4194db10 WVS	258	if (card_id==MIXCOM_ID)
	259	id &= 0x3f;
	260
	261	if (id!=card_id) {
1da177e4 LT	262	release_region(port, 1);
	263	return 0;
	264	}
4194db10 WVS	265	return 1;
4194db10 WVS	266	}
1da177e4 LT	267
	268	static int __init mixcomwd_init(void)
	269	{
	270	int i;
	271	int ret;
	272	int found=0;
	273
21baf3c7 WVS	274	for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
	275	if (checkcard(mixcomwd_io_info[i].ioport,
	276	mixcomwd_io_info[i].id)) {
1da177e4	277	found = 1;
21baf3c7	278	watchdog_port = mixcomwd_io_info[i].ioport;
1da177e4 LT	279	}
	280	}
	281
	282	if (!found) {
1c067318	283	printk(KERN_ERR PFX "No card detected, or port not available.\n");
1da177e4 LT	284	return -ENODEV;
	285	}
	286
	287	ret = misc_register(&mixcomwd_miscdev);
	288	if (ret)
	289	{
27c7742e WVS	290	printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
	291	WATCHDOG_MINOR, ret);
	292	goto error_misc_register_watchdog;
1da177e4 LT	293	}
	294
	295	printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);
	296
	297	return 0;
27c7742e WVS	298
	299	error_misc_register_watchdog:
	300	release_region(watchdog_port, 1);
	301	watchdog_port = 0x0000;
	302	return ret;
1da177e4 LT	303	}
	304
	305	static void __exit mixcomwd_exit(void)
	306	{
	307	if (!nowayout) {
	308	if(mixcomwd_timer_alive) {
1c067318	309	printk(KERN_WARNING PFX "I quit now, hardware will"
1da177e4	310	" probably reboot!\n");
82eb7c50	311	del_timer_sync(&mixcomwd_timer);
1da177e4 LT	312	mixcomwd_timer_alive=0;
	313	}
	314	}
1da177e4	315	misc_deregister(&mixcomwd_miscdev);
27c7742e	316	release_region(watchdog_port,1);
1da177e4 LT	317	}
	318
	319	module_init(mixcomwd_init);
	320	module_exit(mixcomwd_exit);
	321
	322	MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
	323	MODULE_DESCRIPTION("MixCom Watchdog driver");
1c067318	324	MODULE_VERSION(VERSION);
1da177e4 LT	325	MODULE_LICENSE("GPL");
1da177e4 LT	326	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);