[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / geodewdt.c

/* Watchdog timer for machines with the CS5535/CS5536 companion chip
 *
 * Copyright (C) 2006-2007, Advanced Micro Devices, Inc.
 * Copyright (C) 2009  Andres Salomon <dilinger@collabora.co.uk>
 *
 * 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.
 */

#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/platform_device.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>

#include <linux/cs5535.h>

#define GEODEWDT_HZ 500
#define GEODEWDT_SCALE 6
#define GEODEWDT_MAX_SECONDS 131

#define WDT_FLAGS_OPEN 1
#define WDT_FLAGS_ORPHAN 2

#define DRV_NAME "geodewdt"
#define WATCHDOG_NAME "Geode GX/LX WDT"
#define WATCHDOG_TIMEOUT 60

static int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <=131, 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) ")");

static struct platform_device *geodewdt_platform_device;
static unsigned long wdt_flags;
static struct cs5535_mfgpt_timer *wdt_timer;
static int safe_close;

static void geodewdt_ping(void)
{
	/* Stop the counter */
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);

	/* Reset the counter */
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);

	/* Enable the counter */
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
}

static void geodewdt_disable(void)
{
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
}

static int geodewdt_set_heartbeat(int val)
{
	if (val < 1 || val > GEODEWDT_MAX_SECONDS)
		return -EINVAL;

	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ);
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);

	timeout = val;
	return 0;
}

static int geodewdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags))
		return -EBUSY;

	if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags))
		__module_get(THIS_MODULE);

	geodewdt_ping();
	return nonseekable_open(inode, file);
}

static int geodewdt_release(struct inode *inode, struct file *file)
{
	if (safe_close) {
		geodewdt_disable();
		module_put(THIS_MODULE);
	} else {
		pr_crit("Unexpected close - watchdog is not stopping\n");
		geodewdt_ping();

		set_bit(WDT_FLAGS_ORPHAN, &wdt_flags);
	}

	clear_bit(WDT_FLAGS_OPEN, &wdt_flags);
	safe_close = 0;
	return 0;
}

static ssize_t geodewdt_write(struct file *file, const char __user *data,
				size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;
			safe_close = 0;

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

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

				if (c == 'V')
					safe_close = 1;
			}
		}

		geodewdt_ping();
	}
	return len;
}

static long geodewdt_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int interval;

	static const struct watchdog_info ident = {
		.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING
		| WDIOF_MAGICCLOSE,
		.firmware_version =     1,
		.identity =             WATCHDOG_NAME,
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ident,
				    sizeof(ident)) ? -EFAULT : 0;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_SETOPTIONS:
	{
		int options, ret = -EINVAL;

		if (get_user(options, p))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			geodewdt_disable();
			ret = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			geodewdt_ping();
			ret = 0;
		}

		return ret;
	}
	case WDIOC_KEEPALIVE:
		geodewdt_ping();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(interval, p))
			return -EFAULT;

		if (geodewdt_set_heartbeat(interval))
			return -EINVAL;
	/* Fall through */
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);

	default:
		return -ENOTTY;
	}

	return 0;
}

static const struct file_operations geodewdt_fops = {
	.owner          = THIS_MODULE,
	.llseek         = no_llseek,
	.write          = geodewdt_write,
	.unlocked_ioctl = geodewdt_ioctl,
	.open           = geodewdt_open,
	.release        = geodewdt_release,
};

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

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

	wdt_timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING);
	if (!wdt_timer) {
		pr_err("No timers were available\n");
		return -ENODEV;
	}

	/* Set up the timer */

	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP,
			  GEODEWDT_SCALE | (3 << 8));

	/* Set up comparator 2 to reset when the event fires */
	cs5535_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1);

	/* Set up the initial timeout */

	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2,
		timeout * GEODEWDT_HZ);

	ret = misc_register(&geodewdt_miscdev);

	return ret;
}

static int geodewdt_remove(struct platform_device *dev)
{
	misc_deregister(&geodewdt_miscdev);
	return 0;
}

static void geodewdt_shutdown(struct platform_device *dev)
{
	geodewdt_disable();
}

static struct platform_driver geodewdt_driver = {
	.probe		= geodewdt_probe,
	.remove		= geodewdt_remove,
	.shutdown	= geodewdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= DRV_NAME,
	},
};

static int __init geodewdt_init(void)
{
	int ret;

	ret = platform_driver_register(&geodewdt_driver);
	if (ret)
		return ret;

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

	return 0;
err:
	platform_driver_unregister(&geodewdt_driver);
	return ret;
}

static void __exit geodewdt_exit(void)
{
	platform_device_unregister(geodewdt_platform_device);
	platform_driver_unregister(&geodewdt_driver);
}

module_init(geodewdt_init);
module_exit(geodewdt_exit);

MODULE_AUTHOR("Advanced Micro Devices, Inc");
MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
9b0fd114	1	/* Watchdog timer for machines with the CS5535/CS5536 companion chip
0b36086b JC	2	*
0b36086b JC	3	* Copyright (C) 2006-2007, Advanced Micro Devices, Inc.
9b0fd114	4	* Copyright (C) 2009 Andres Salomon <dilinger@collabora.co.uk>
0b36086b JC	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
27c766aa	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0b36086b JC	13
	14	#include <linux/module.h>
	15	#include <linux/moduleparam.h>
	16	#include <linux/types.h>
	17	#include <linux/miscdevice.h>
	18	#include <linux/watchdog.h>
	19	#include <linux/fs.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/reboot.h>
089ab079	22	#include <linux/uaccess.h>
0b36086b	23
9b0fd114	24	#include <linux/cs5535.h>
0b36086b JC	25
	26	#define GEODEWDT_HZ 500
	27	#define GEODEWDT_SCALE 6
	28	#define GEODEWDT_MAX_SECONDS 131
	29
	30	#define WDT_FLAGS_OPEN 1
	31	#define WDT_FLAGS_ORPHAN 2
	32
	33	#define DRV_NAME "geodewdt"
	34	#define WATCHDOG_NAME "Geode GX/LX WDT"
	35	#define WATCHDOG_TIMEOUT 60
	36
	37	static int timeout = WATCHDOG_TIMEOUT;
	38	module_param(timeout, int, 0);
143a2e54 WVS	39	MODULE_PARM_DESC(timeout,
	40	"Watchdog timeout in seconds. 1<= timeout <=131, default="
	41	__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
0b36086b	42
86a1e189 WVS	43	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	44	module_param(nowayout, bool, 0);
143a2e54 WVS	45	MODULE_PARM_DESC(nowayout,
	46	"Watchdog cannot be stopped once started (default="
	47	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
0b36086b JC	48
	49	static struct platform_device *geodewdt_platform_device;
	50	static unsigned long wdt_flags;
9b0fd114	51	static struct cs5535_mfgpt_timer *wdt_timer;
0b36086b JC	52	static int safe_close;
	53
	54	static void geodewdt_ping(void)
	55	{
	56	/* Stop the counter */
9b0fd114	57	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
0b36086b JC	58
0b36086b JC	59	/* Reset the counter */
9b0fd114	60	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
0b36086b JC	61
0b36086b JC	62	/* Enable the counter */
9b0fd114	63	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
0b36086b JC	64	}
	65
	66	static void geodewdt_disable(void)
	67	{
9b0fd114 AS	68	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
9b0fd114 AS	69	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
0b36086b JC	70	}
	71
	72	static int geodewdt_set_heartbeat(int val)
	73	{
	74	if (val < 1 \|\| val > GEODEWDT_MAX_SECONDS)
	75	return -EINVAL;
	76
9b0fd114 AS	77	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0);
	78	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ);
	79	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0);
	80	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
0b36086b JC	81
	82	timeout = val;
	83	return 0;
	84	}
	85
7944d3a5	86	static int geodewdt_open(struct inode inode, struct file file)
0b36086b	87	{
7944d3a5 WVS	88	if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags))
7944d3a5 WVS	89	return -EBUSY;
0b36086b	90
7944d3a5 WVS	91	if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags))
7944d3a5 WVS	92	__module_get(THIS_MODULE);
0b36086b JC	93
0b36086b JC	94	geodewdt_ping();
7944d3a5	95	return nonseekable_open(inode, file);
0b36086b JC	96	}
0b36086b JC	97
7944d3a5	98	static int geodewdt_release(struct inode inode, struct file file)
0b36086b JC	99	{
	100	if (safe_close) {
	101	geodewdt_disable();
	102	module_put(THIS_MODULE);
7944d3a5	103	} else {
27c766aa	104	pr_crit("Unexpected close - watchdog is not stopping\n");
0b36086b JC	105	geodewdt_ping();
	106
	107	set_bit(WDT_FLAGS_ORPHAN, &wdt_flags);
	108	}
	109
	110	clear_bit(WDT_FLAGS_OPEN, &wdt_flags);
	111	safe_close = 0;
	112	return 0;
	113	}
	114
7944d3a5 WVS	115	static ssize_t geodewdt_write(struct file file, const char __user data,
7944d3a5 WVS	116	size_t len, loff_t *ppos)
0b36086b	117	{
7944d3a5	118	if (len) {
0b36086b JC	119	if (!nowayout) {
	120	size_t i;
	121	safe_close = 0;
	122
	123	for (i = 0; i != len; i++) {
	124	char c;
	125
	126	if (get_user(c, data + i))
	127	return -EFAULT;
	128
	129	if (c == 'V')
	130	safe_close = 1;
	131	}
	132	}
	133
	134	geodewdt_ping();
	135	}
	136	return len;
	137	}
	138
7275fc8c WVS	139	static long geodewdt_ioctl(struct file *file, unsigned int cmd,
7275fc8c WVS	140	unsigned long arg)
0b36086b JC	141	{
	142	void __user argp = (void __user )arg;
	143	int __user *p = argp;
	144	int interval;
	145
42747d71	146	static const struct watchdog_info ident = {
0b36086b JC	147	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING
	148	\| WDIOF_MAGICCLOSE,
	149	.firmware_version = 1,
	150	.identity = WATCHDOG_NAME,
7944d3a5	151	};
0b36086b	152
5eb82498	153	switch (cmd) {
0b36086b JC	154	case WDIOC_GETSUPPORT:
	155	return copy_to_user(argp, &ident,
	156	sizeof(ident)) ? -EFAULT : 0;
	157	break;
	158
	159	case WDIOC_GETSTATUS:
	160	case WDIOC_GETBOOTSTATUS:
	161	return put_user(0, p);
	162
0b36086b JC	163	case WDIOC_SETOPTIONS:
	164	{
	165	int options, ret = -EINVAL;
	166
	167	if (get_user(options, p))
	168	return -EFAULT;
	169
	170	if (options & WDIOS_DISABLECARD) {
	171	geodewdt_disable();
	172	ret = 0;
	173	}
	174
	175	if (options & WDIOS_ENABLECARD) {
	176	geodewdt_ping();
	177	ret = 0;
	178	}
	179
	180	return ret;
	181	}
0c06090c WVS	182	case WDIOC_KEEPALIVE:
	183	geodewdt_ping();
	184	return 0;
	185
	186	case WDIOC_SETTIMEOUT:
	187	if (get_user(interval, p))
	188	return -EFAULT;
	189
	190	if (geodewdt_set_heartbeat(interval))
	191	return -EINVAL;
	192	/* Fall through */
	193	case WDIOC_GETTIMEOUT:
	194	return put_user(timeout, p);
	195
0b36086b JC	196	default:
	197	return -ENOTTY;
	198	}
	199
	200	return 0;
	201	}
	202
	203	static const struct file_operations geodewdt_fops = {
7944d3a5 WVS	204	.owner = THIS_MODULE,
	205	.llseek = no_llseek,
	206	.write = geodewdt_write,
7275fc8c	207	.unlocked_ioctl = geodewdt_ioctl,
7944d3a5 WVS	208	.open = geodewdt_open,
7944d3a5 WVS	209	.release = geodewdt_release,
0b36086b JC	210	};
	211
	212	static struct miscdevice geodewdt_miscdev = {
	213	.minor = WATCHDOG_MINOR,
	214	.name = "watchdog",
7944d3a5	215	.fops = &geodewdt_fops,
0b36086b JC	216	};
0b36086b JC	217
2d991a16	218	static int geodewdt_probe(struct platform_device *dev)
0b36086b	219	{
9b0fd114	220	int ret;
0b36086b	221
9b0fd114 AS	222	wdt_timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING);
9b0fd114 AS	223	if (!wdt_timer) {
27c766aa	224	pr_err("No timers were available\n");
0b36086b JC	225	return -ENODEV;
	226	}
	227
0b36086b JC	228	/* Set up the timer */
0b36086b JC	229
9b0fd114	230	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP,
0b36086b JC	231	GEODEWDT_SCALE \| (3 << 8));
	232
	233	/* Set up comparator 2 to reset when the event fires */
9b0fd114	234	cs5535_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1);
0b36086b JC	235
	236	/* Set up the initial timeout */
	237
9b0fd114	238	cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2,
0b36086b JC	239	timeout * GEODEWDT_HZ);
	240
	241	ret = misc_register(&geodewdt_miscdev);
	242
	243	return ret;
	244	}
	245
4b12b896	246	static int geodewdt_remove(struct platform_device *dev)
0b36086b JC	247	{
	248	misc_deregister(&geodewdt_miscdev);
	249	return 0;
	250	}
	251
7944d3a5	252	static void geodewdt_shutdown(struct platform_device *dev)
0b36086b JC	253	{
	254	geodewdt_disable();
	255	}
	256
	257	static struct platform_driver geodewdt_driver = {
	258	.probe = geodewdt_probe,
82268714	259	.remove = geodewdt_remove,
0b36086b JC	260	.shutdown = geodewdt_shutdown,
	261	.driver = {
	262	.owner = THIS_MODULE,
	263	.name = DRV_NAME,
	264	},
	265	};
	266
7944d3a5	267	static int __init geodewdt_init(void)
0b36086b JC	268	{
	269	int ret;
	270
	271	ret = platform_driver_register(&geodewdt_driver);
	272	if (ret)
	273	return ret;
	274
143a2e54 WVS	275	geodewdt_platform_device = platform_device_register_simple(DRV_NAME,
143a2e54 WVS	276	-1, NULL, 0);
0b36086b JC	277	if (IS_ERR(geodewdt_platform_device)) {
	278	ret = PTR_ERR(geodewdt_platform_device);
	279	goto err;
	280	}
	281
	282	return 0;
	283	err:
	284	platform_driver_unregister(&geodewdt_driver);
	285	return ret;
	286	}
	287
7944d3a5	288	static void __exit geodewdt_exit(void)
0b36086b JC	289	{
	290	platform_device_unregister(geodewdt_platform_device);
	291	platform_driver_unregister(&geodewdt_driver);
	292	}
	293
	294	module_init(geodewdt_init);
	295	module_exit(geodewdt_exit);
	296
	297	MODULE_AUTHOR("Advanced Micro Devices, Inc");
	298	MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver");
	299	MODULE_LICENSE("GPL");
	300	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);