[linux-2.6-block.git] / drivers / watchdog / mixcomwd.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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>
 *
 * 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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define VERSION "0.6"
#define WATCHDOG_NAME "mixcomwd"

#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 <linux/uaccess.h>
#include <linux/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[] = {
	/* 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(struct timer_list *unused);

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);
static char expect_close;

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

static void mixcomwd_timerfun(struct timer_list *unused)
{
	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 stream_open(inode, file);
}

static int mixcomwd_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		if (mixcomwd_timer_alive) {
			pr_err("release called while internal timer alive\n");
			return -EBUSY;
		}
		mixcomwd_timer_alive = 1;
		mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
	} else
		pr_crit("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 long mixcomwd_ioctl(struct file *file,
				unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int status;
	static const struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = "MixCOM watchdog",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		break;
	case WDIOC_GETSTATUS:
		status = mixcomwd_opened;
		if (!nowayout)
			status |= mixcomwd_timer_alive;
		return put_user(status, p);
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	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,
	.unlocked_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, ret, 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) {
		pr_err("No card detected, or port not available\n");
		return -ENODEV;
	}

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

	pr_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) {
			pr_warn("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");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* MixCom Watchdog: A Simple Hardware Watchdog Device
	4	* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
	5	*
	6	* Author: Gergely Madarasz <gorgo@itc.hu>
	7	*
	8	* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
	9	*
1da177e4 LT	10	* Version 0.1 (99/04/15):
	11	* - first version
	12	*
	13	* Version 0.2 (99/06/16):
	14	* - added kernel timer watchdog ping after close
	15	* since the hardware does not support watchdog shutdown
	16	*
	17	* Version 0.3 (99/06/21):
	18	* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
	19	*
	20	* Version 0.3.1 (99/06/22):
	21	* - allow module removal while internal timer is active,
	22	* print warning about probable reset
	23	*
	24	* Version 0.4 (99/11/15):
	25	* - support for one more type board
	26	*
	27	* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
39309645 AC	28	* - added nowayout module option to override
39309645 AC	29	* CONFIG_WATCHDOG_NOWAYOUT
b10958d3 WVS	30	*
	31	* Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
	32	* - make mixcomwd_opened unsigned,
	33	* removed lock_kernel/unlock_kernel from mixcomwd_release,
	34	* modified ioctl a bit to conform to API
1da177e4 LT	35	*/
1da177e4 LT	36
27c766aa JP	37	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	38
b10958d3	39	#define VERSION "0.6"
1c067318	40	#define WATCHDOG_NAME "mixcomwd"
1da177e4 LT	41
	42	#include <linux/module.h>
	43	#include <linux/moduleparam.h>
1da177e4 LT	44	#include <linux/types.h>
	45	#include <linux/miscdevice.h>
	46	#include <linux/ioport.h>
	47	#include <linux/watchdog.h>
	48	#include <linux/fs.h>
	49	#include <linux/reboot.h>
	50	#include <linux/init.h>
4e57b681 TS	51	#include <linux/jiffies.h>
4e57b681 TS	52	#include <linux/timer.h>
39309645 AC	53	#include <linux/uaccess.h>
39309645 AC	54	#include <linux/io.h>
1da177e4	55
63e6e17e WVS	56	/*
	57	* We have two types of cards that can be probed:
	58	* 1) The Mixcom cards: these cards can be found at addresses
	59	* 0x180, 0x280, 0x380 with an additional offset of 0xc10.
	60	* (Or 0xd90, 0xe90, 0xf90).
	61	* 2) The FlashCOM cards: these cards can be set up at
	62	* 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
	63	* (Or 0x304 -> 0x37c in 0x8 jumps).
	64	* Each card has it's own ID.
	65	*/
1da177e4	66	#define MIXCOM_ID 0x11
1da177e4	67	#define FLASHCOM_ID 0x18
21baf3c7 WVS	68	static struct {
	69	int ioport;
	70	int id;
1d131368	71	} mixcomwd_io_info[] = {
21baf3c7 WVS	72	/* The Mixcom cards */
	73	{0x0d90, MIXCOM_ID},
	74	{0x0e90, MIXCOM_ID},
	75	{0x0f90, MIXCOM_ID},
	76	/* The FlashCOM cards */
	77	{0x0304, FLASHCOM_ID},
	78	{0x030c, FLASHCOM_ID},
	79	{0x0314, FLASHCOM_ID},
	80	{0x031c, FLASHCOM_ID},
	81	{0x0324, FLASHCOM_ID},
	82	{0x032c, FLASHCOM_ID},
	83	{0x0334, FLASHCOM_ID},
	84	{0x033c, FLASHCOM_ID},
	85	{0x0344, FLASHCOM_ID},
	86	{0x034c, FLASHCOM_ID},
	87	{0x0354, FLASHCOM_ID},
	88	{0x035c, FLASHCOM_ID},
	89	{0x0364, FLASHCOM_ID},
	90	{0x036c, FLASHCOM_ID},
	91	{0x0374, FLASHCOM_ID},
	92	{0x037c, FLASHCOM_ID},
	93	/* The end of the list */
	94	{0x0000, 0},
	95	};
1da177e4	96
24ed960a	97	static void mixcomwd_timerfun(struct timer_list *unused);
82eb7c50	98
1da177e4 LT	99	static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
	100
	101	static int watchdog_port;
	102	static int mixcomwd_timer_alive;
1d27e3e2	103	static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun);
1da177e4 LT	104	static char expect_close;
1da177e4 LT	105
86a1e189 WVS	106	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	107	module_param(nowayout, bool, 0);
39309645 AC	108	MODULE_PARM_DESC(nowayout,
	109	"Watchdog cannot be stopped once started (default="
	110	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	111
	112	static void mixcomwd_ping(void)
	113	{
39309645	114	outb_p(55, watchdog_port);
1da177e4 LT	115	return;
	116	}
	117
24ed960a	118	static void mixcomwd_timerfun(struct timer_list *unused)
1da177e4 LT	119	{
1da177e4 LT	120	mixcomwd_ping();
82eb7c50	121	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
1da177e4 LT	122	}
	123
	124	/*
	125	* Allow only one person to hold it open
	126	*/
	127
	128	static int mixcomwd_open(struct inode inode, struct file file)
	129	{
39309645	130	if (test_and_set_bit(0, &mixcomwd_opened))
1da177e4	131	return -EBUSY;
39309645	132
1da177e4 LT	133	mixcomwd_ping();
1da177e4 LT	134
39309645	135	if (nowayout)
1da177e4 LT	136	/*
	137	* fops_get() code via open() has already done
	138	* a try_module_get() so it is safe to do the
	139	* __module_get().
	140	*/
	141	__module_get(THIS_MODULE);
39309645 AC	142	else {
39309645 AC	143	if (mixcomwd_timer_alive) {
1da177e4	144	del_timer(&mixcomwd_timer);
39309645	145	mixcomwd_timer_alive = 0;
1da177e4 LT	146	}
1da177e4 LT	147	}
c5bf68fe	148	return stream_open(inode, file);
1da177e4 LT	149	}
	150
	151	static int mixcomwd_release(struct inode inode, struct file file)
	152	{
	153	if (expect_close == 42) {
39309645	154	if (mixcomwd_timer_alive) {
27c766aa	155	pr_err("release called while internal timer alive\n");
1da177e4 LT	156	return -EBUSY;
1da177e4 LT	157	}
39309645	158	mixcomwd_timer_alive = 1;
82eb7c50	159	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
39309645	160	} else
27c766aa	161	pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4	162
39309645 AC	163	clear_bit(0, &mixcomwd_opened);
39309645 AC	164	expect_close = 0;
1da177e4 LT	165	return 0;
	166	}
	167
	168
39309645 AC	169	static ssize_t mixcomwd_write(struct file file, const char __user data,
39309645 AC	170	size_t len, loff_t *ppos)
1da177e4	171	{
39309645	172	if (len) {
1da177e4 LT	173	if (!nowayout) {
	174	size_t i;
	175
	176	/* In case it was set long ago */
	177	expect_close = 0;
	178
	179	for (i = 0; i != len; i++) {
	180	char c;
	181	if (get_user(c, data + i))
	182	return -EFAULT;
	183	if (c == 'V')
	184	expect_close = 42;
	185	}
	186	}
	187	mixcomwd_ping();
	188	}
	189	return len;
	190	}
	191
39309645 AC	192	static long mixcomwd_ioctl(struct file *file,
39309645 AC	193	unsigned int cmd, unsigned long arg)
1da177e4 LT	194	{
	195	void __user argp = (void __user )arg;
	196	int __user *p = argp;
	197	int status;
42747d71	198	static const struct watchdog_info ident = {
1da177e4 LT	199	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	200	.firmware_version = 1,
	201	.identity = "MixCOM watchdog",
	202	};
	203
39309645	204	switch (cmd) {
0c06090c WVS	205	case WDIOC_GETSUPPORT:
	206	if (copy_to_user(argp, &ident, sizeof(ident)))
	207	return -EFAULT;
	208	break;
39309645 AC	209	case WDIOC_GETSTATUS:
	210	status = mixcomwd_opened;
	211	if (!nowayout)
	212	status \|= mixcomwd_timer_alive;
	213	return put_user(status, p);
	214	case WDIOC_GETBOOTSTATUS:
	215	return put_user(0, p);
39309645 AC	216	case WDIOC_KEEPALIVE:
	217	mixcomwd_ping();
	218	break;
	219	default:
	220	return -ENOTTY;
1da177e4 LT	221	}
	222	return 0;
	223	}
	224
10a29304	225	static const struct file_operations mixcomwd_fops = {
1da177e4 LT	226	.owner = THIS_MODULE,
	227	.llseek = no_llseek,
	228	.write = mixcomwd_write,
39309645	229	.unlocked_ioctl = mixcomwd_ioctl,
1da177e4 LT	230	.open = mixcomwd_open,
	231	.release = mixcomwd_release,
	232	};
	233
10a29304	234	static struct miscdevice mixcomwd_miscdev = {
1da177e4 LT	235	.minor = WATCHDOG_MINOR,
	236	.name = "watchdog",
	237	.fops = &mixcomwd_fops,
	238	};
	239
4194db10	240	static int __init checkcard(int port, int card_id)
1da177e4 LT	241	{
	242	int id;
	243
39309645	244	if (!request_region(port, 1, "MixCOM watchdog"))
1da177e4	245	return 0;
1da177e4	246
39309645 AC	247	id = inb_p(port);
39309645 AC	248	if (card_id == MIXCOM_ID)
4194db10 WVS	249	id &= 0x3f;
4194db10 WVS	250
39309645	251	if (id != card_id) {
1da177e4 LT	252	release_region(port, 1);
	253	return 0;
	254	}
4194db10 WVS	255	return 1;
4194db10 WVS	256	}
1da177e4 LT	257
	258	static int __init mixcomwd_init(void)
	259	{
39309645	260	int i, ret, found = 0;
1da177e4	261
21baf3c7 WVS	262	for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
	263	if (checkcard(mixcomwd_io_info[i].ioport,
	264	mixcomwd_io_info[i].id)) {
1da177e4	265	found = 1;
21baf3c7	266	watchdog_port = mixcomwd_io_info[i].ioport;
1da177e4 LT	267	}
	268	}
	269
	270	if (!found) {
27c766aa	271	pr_err("No card detected, or port not available\n");
1da177e4 LT	272	return -ENODEV;
	273	}
	274
	275	ret = misc_register(&mixcomwd_miscdev);
39309645	276	if (ret) {
27c766aa JP	277	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	278	WATCHDOG_MINOR, ret);
27c7742e	279	goto error_misc_register_watchdog;
1da177e4 LT	280	}
1da177e4 LT	281
27c766aa JP	282	pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
27c766aa JP	283	VERSION, watchdog_port);
1da177e4 LT	284
1da177e4 LT	285	return 0;
27c7742e WVS	286
	287	error_misc_register_watchdog:
	288	release_region(watchdog_port, 1);
	289	watchdog_port = 0x0000;
	290	return ret;
1da177e4 LT	291	}
	292
	293	static void __exit mixcomwd_exit(void)
	294	{
	295	if (!nowayout) {
39309645	296	if (mixcomwd_timer_alive) {
27c766aa	297	pr_warn("I quit now, hardware will probably reboot!\n");
82eb7c50	298	del_timer_sync(&mixcomwd_timer);
39309645	299	mixcomwd_timer_alive = 0;
1da177e4 LT	300	}
1da177e4 LT	301	}
1da177e4	302	misc_deregister(&mixcomwd_miscdev);
39309645	303	release_region(watchdog_port, 1);
1da177e4 LT	304	}
	305
	306	module_init(mixcomwd_init);
	307	module_exit(mixcomwd_exit);
	308
	309	MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
	310	MODULE_DESCRIPTION("MixCom Watchdog driver");
1c067318	311	MODULE_VERSION(VERSION);
1da177e4	312	MODULE_LICENSE("GPL");