[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / 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 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(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 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(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) {
			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");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
	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>
	32	* - added nowayout module option to override
	33	* CONFIG_WATCHDOG_NOWAYOUT
	34	*
	35	* Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
	36	* - make mixcomwd_opened unsigned,
	37	* removed lock_kernel/unlock_kernel from mixcomwd_release,
	38	* modified ioctl a bit to conform to API
	39	*
	40	*/
	41
	42	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	43
	44	#define VERSION "0.6"
	45	#define WATCHDOG_NAME "mixcomwd"
	46
	47	#include <linux/module.h>
	48	#include <linux/moduleparam.h>
	49	#include <linux/types.h>
	50	#include <linux/miscdevice.h>
	51	#include <linux/ioport.h>
	52	#include <linux/watchdog.h>
	53	#include <linux/fs.h>
	54	#include <linux/reboot.h>
	55	#include <linux/init.h>
	56	#include <linux/jiffies.h>
	57	#include <linux/timer.h>
	58	#include <linux/uaccess.h>
	59	#include <linux/io.h>
	60
	61	/*
	62	* We have two types of cards that can be probed:
	63	* 1) The Mixcom cards: these cards can be found at addresses
	64	* 0x180, 0x280, 0x380 with an additional offset of 0xc10.
	65	* (Or 0xd90, 0xe90, 0xf90).
	66	* 2) The FlashCOM cards: these cards can be set up at
	67	* 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
	68	* (Or 0x304 -> 0x37c in 0x8 jumps).
	69	* Each card has it's own ID.
	70	*/
	71	#define MIXCOM_ID 0x11
	72	#define FLASHCOM_ID 0x18
	73	static struct {
	74	int ioport;
	75	int id;
	76	} mixcomwd_io_info[] = {
	77	/* The Mixcom cards */
	78	{0x0d90, MIXCOM_ID},
	79	{0x0e90, MIXCOM_ID},
	80	{0x0f90, MIXCOM_ID},
	81	/* The FlashCOM cards */
	82	{0x0304, FLASHCOM_ID},
	83	{0x030c, FLASHCOM_ID},
	84	{0x0314, FLASHCOM_ID},
	85	{0x031c, FLASHCOM_ID},
	86	{0x0324, FLASHCOM_ID},
	87	{0x032c, FLASHCOM_ID},
	88	{0x0334, FLASHCOM_ID},
	89	{0x033c, FLASHCOM_ID},
	90	{0x0344, FLASHCOM_ID},
	91	{0x034c, FLASHCOM_ID},
	92	{0x0354, FLASHCOM_ID},
	93	{0x035c, FLASHCOM_ID},
	94	{0x0364, FLASHCOM_ID},
	95	{0x036c, FLASHCOM_ID},
	96	{0x0374, FLASHCOM_ID},
	97	{0x037c, FLASHCOM_ID},
	98	/* The end of the list */
	99	{0x0000, 0},
	100	};
	101
	102	static void mixcomwd_timerfun(unsigned long d);
	103
	104	static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
	105
	106	static int watchdog_port;
	107	static int mixcomwd_timer_alive;
	108	static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
	109	static char expect_close;
	110
	111	static bool nowayout = WATCHDOG_NOWAYOUT;
	112	module_param(nowayout, bool, 0);
	113	MODULE_PARM_DESC(nowayout,
	114	"Watchdog cannot be stopped once started (default="
	115	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	116
	117	static void mixcomwd_ping(void)
	118	{
	119	outb_p(55, watchdog_port);
	120	return;
	121	}
	122
	123	static void mixcomwd_timerfun(unsigned long d)
	124	{
	125	mixcomwd_ping();
	126	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
	127	}
	128
	129	/*
	130	* Allow only one person to hold it open
	131	*/
	132
	133	static int mixcomwd_open(struct inode inode, struct file file)
	134	{
	135	if (test_and_set_bit(0, &mixcomwd_opened))
	136	return -EBUSY;
	137
	138	mixcomwd_ping();
	139
	140	if (nowayout)
	141	/*
	142	* fops_get() code via open() has already done
	143	* a try_module_get() so it is safe to do the
	144	* __module_get().
	145	*/
	146	__module_get(THIS_MODULE);
	147	else {
	148	if (mixcomwd_timer_alive) {
	149	del_timer(&mixcomwd_timer);
	150	mixcomwd_timer_alive = 0;
	151	}
	152	}
	153	return nonseekable_open(inode, file);
	154	}
	155
	156	static int mixcomwd_release(struct inode inode, struct file file)
	157	{
	158	if (expect_close == 42) {
	159	if (mixcomwd_timer_alive) {
	160	pr_err("release called while internal timer alive\n");
	161	return -EBUSY;
	162	}
	163	mixcomwd_timer_alive = 1;
	164	mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
	165	} else
	166	pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
	167
	168	clear_bit(0, &mixcomwd_opened);
	169	expect_close = 0;
	170	return 0;
	171	}
	172
	173
	174	static ssize_t mixcomwd_write(struct file file, const char __user data,
	175	size_t len, loff_t *ppos)
	176	{
	177	if (len) {
	178	if (!nowayout) {
	179	size_t i;
	180
	181	/* In case it was set long ago */
	182	expect_close = 0;
	183
	184	for (i = 0; i != len; i++) {
	185	char c;
	186	if (get_user(c, data + i))
	187	return -EFAULT;
	188	if (c == 'V')
	189	expect_close = 42;
	190	}
	191	}
	192	mixcomwd_ping();
	193	}
	194	return len;
	195	}
	196
	197	static long mixcomwd_ioctl(struct file *file,
	198	unsigned int cmd, unsigned long arg)
	199	{
	200	void __user argp = (void __user )arg;
	201	int __user *p = argp;
	202	int status;
	203	static const struct watchdog_info ident = {
	204	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	205	.firmware_version = 1,
	206	.identity = "MixCOM watchdog",
	207	};
	208
	209	switch (cmd) {
	210	case WDIOC_GETSUPPORT:
	211	if (copy_to_user(argp, &ident, sizeof(ident)))
	212	return -EFAULT;
	213	break;
	214	case WDIOC_GETSTATUS:
	215	status = mixcomwd_opened;
	216	if (!nowayout)
	217	status \|= mixcomwd_timer_alive;
	218	return put_user(status, p);
	219	case WDIOC_GETBOOTSTATUS:
	220	return put_user(0, p);
	221	case WDIOC_KEEPALIVE:
	222	mixcomwd_ping();
	223	break;
	224	default:
	225	return -ENOTTY;
	226	}
	227	return 0;
	228	}
	229
	230	static const struct file_operations mixcomwd_fops = {
	231	.owner = THIS_MODULE,
	232	.llseek = no_llseek,
	233	.write = mixcomwd_write,
	234	.unlocked_ioctl = mixcomwd_ioctl,
	235	.open = mixcomwd_open,
	236	.release = mixcomwd_release,
	237	};
	238
	239	static struct miscdevice mixcomwd_miscdev = {
	240	.minor = WATCHDOG_MINOR,
	241	.name = "watchdog",
	242	.fops = &mixcomwd_fops,
	243	};
	244
	245	static int __init checkcard(int port, int card_id)
	246	{
	247	int id;
	248
	249	if (!request_region(port, 1, "MixCOM watchdog"))
	250	return 0;
	251
	252	id = inb_p(port);
	253	if (card_id == MIXCOM_ID)
	254	id &= 0x3f;
	255
	256	if (id != card_id) {
	257	release_region(port, 1);
	258	return 0;
	259	}
	260	return 1;
	261	}
	262
	263	static int __init mixcomwd_init(void)
	264	{
	265	int i, ret, found = 0;
	266
	267	for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
	268	if (checkcard(mixcomwd_io_info[i].ioport,
	269	mixcomwd_io_info[i].id)) {
	270	found = 1;
	271	watchdog_port = mixcomwd_io_info[i].ioport;
	272	}
	273	}
	274
	275	if (!found) {
	276	pr_err("No card detected, or port not available\n");
	277	return -ENODEV;
	278	}
	279
	280	ret = misc_register(&mixcomwd_miscdev);
	281	if (ret) {
	282	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	283	WATCHDOG_MINOR, ret);
	284	goto error_misc_register_watchdog;
	285	}
	286
	287	pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
	288	VERSION, watchdog_port);
	289
	290	return 0;
	291
	292	error_misc_register_watchdog:
	293	release_region(watchdog_port, 1);
	294	watchdog_port = 0x0000;
	295	return ret;
	296	}
	297
	298	static void __exit mixcomwd_exit(void)
	299	{
	300	if (!nowayout) {
	301	if (mixcomwd_timer_alive) {
	302	pr_warn("I quit now, hardware will probably reboot!\n");
	303	del_timer_sync(&mixcomwd_timer);
	304	mixcomwd_timer_alive = 0;
	305	}
	306	}
	307	misc_deregister(&mixcomwd_miscdev);
	308	release_region(watchdog_port, 1);
	309	}
	310
	311	module_init(mixcomwd_init);
	312	module_exit(mixcomwd_exit);
	313
	314	MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
	315	MODULE_DESCRIPTION("MixCom Watchdog driver");
	316	MODULE_VERSION(VERSION);
	317	MODULE_LICENSE("GPL");
	318	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);