[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / txx9wdt.c

/*
 * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs
 *
 * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#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/reboot.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <asm/txx9tmr.h>

#define TIMER_MARGIN	60		/* Default is 60 seconds */

static int timeout = TIMER_MARGIN;	/* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. "
	"(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
	"default=" __MODULE_STRING(TIMER_MARGIN) ")");

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) ")");

#define WD_TIMER_CCD	7	/* 1/256 */
#define WD_TIMER_CLK	(clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
#define WD_MAX_TIMEOUT	((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)

static unsigned long txx9wdt_alive;
static int expect_close;
static struct txx9_tmr_reg __iomem *txx9wdt_reg;
static struct clk *txx9_imclk;
static DEFINE_SPINLOCK(txx9_lock);

static void txx9wdt_ping(void)
{
	spin_lock(&txx9_lock);
	__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
	spin_unlock(&txx9_lock);
}

static void txx9wdt_start(void)
{
	spin_lock(&txx9_lock);
	__raw_writel(WD_TIMER_CLK * timeout, &txx9wdt_reg->cpra);
	__raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
	__raw_writel(0, &txx9wdt_reg->tisr);	/* clear pending interrupt */
	__raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG,
		     &txx9wdt_reg->tcr);
	__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
	spin_unlock(&txx9_lock);
}

static void txx9wdt_stop(void)
{
	spin_lock(&txx9_lock);
	__raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
	__raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
		     &txx9wdt_reg->tcr);
	spin_unlock(&txx9_lock);
}

static int txx9wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &txx9wdt_alive))
		return -EBUSY;

	if (__raw_readl(&txx9wdt_reg->tcr) & TXx9_TMTCR_TCE) {
		clear_bit(0, &txx9wdt_alive);
		return -EBUSY;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	txx9wdt_start();
	return nonseekable_open(inode, file);
}

static int txx9wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close)
		txx9wdt_stop();
	else {
		printk(KERN_CRIT "txx9wdt: "
		       "Unexpected close, not stopping watchdog!\n");
		txx9wdt_ping();
	}
	clear_bit(0, &txx9wdt_alive);
	expect_close = 0;
	return 0;
}

static ssize_t txx9wdt_write(struct file *file, const char __user *data,
			     size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			expect_close = 0;
			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 1;
			}
		}
		txx9wdt_ping();
	}
	return len;
}

static long txx9wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_timeout;
	static const struct watchdog_info ident = {
		.options =		WDIOF_SETTIMEOUT |
					WDIOF_KEEPALIVEPING |
					WDIOF_MAGICCLOSE,
		.firmware_version =	0,
		.identity =		"Hardware Watchdog for TXx9",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_KEEPALIVE:
		txx9wdt_ping();
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		if (new_timeout < 1 || new_timeout > WD_MAX_TIMEOUT)
			return -EINVAL;
		timeout = new_timeout;
		txx9wdt_stop();
		txx9wdt_start();
		/* Fall */
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);
	default:
		return -ENOTTY;
	}
}

static int txx9wdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		txx9wdt_stop();
	return NOTIFY_DONE;
}

static const struct file_operations txx9wdt_fops = {
	.owner		=	THIS_MODULE,
	.llseek		=	no_llseek,
	.write		=	txx9wdt_write,
	.unlocked_ioctl =	txx9wdt_ioctl,
	.open		=	txx9wdt_open,
	.release	=	txx9wdt_release,
};

static struct miscdevice txx9wdt_miscdev = {
	.minor	=	WATCHDOG_MINOR,
	.name	=	"watchdog",
	.fops	=	&txx9wdt_fops,
};

static struct notifier_block txx9wdt_notifier = {
	.notifier_call = txx9wdt_notify_sys,
};

static int __init txx9wdt_probe(struct platform_device *dev)
{
	struct resource *res;
	int ret;

	txx9_imclk = clk_get(NULL, "imbus_clk");
	if (IS_ERR(txx9_imclk)) {
		ret = PTR_ERR(txx9_imclk);
		txx9_imclk = NULL;
		goto exit;
	}
	ret = clk_enable(txx9_imclk);
	if (ret) {
		clk_put(txx9_imclk);
		txx9_imclk = NULL;
		goto exit;
	}

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
		goto exit_busy;
	if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
				     "txx9wdt"))
		goto exit_busy;
	txx9wdt_reg = devm_ioremap(&dev->dev, res->start, resource_size(res));
	if (!txx9wdt_reg)
		goto exit_busy;

	ret = register_reboot_notifier(&txx9wdt_notifier);
	if (ret)
		goto exit;

	ret = misc_register(&txx9wdt_miscdev);
	if (ret) {
		unregister_reboot_notifier(&txx9wdt_notifier);
		goto exit;
	}

	printk(KERN_INFO "Hardware Watchdog Timer for TXx9: "
	       "timeout=%d sec (max %ld) (nowayout= %d)\n",
	       timeout, WD_MAX_TIMEOUT, nowayout);

	return 0;
exit_busy:
	ret = -EBUSY;
exit:
	if (txx9_imclk) {
		clk_disable(txx9_imclk);
		clk_put(txx9_imclk);
	}
	return ret;
}

static int __exit txx9wdt_remove(struct platform_device *dev)
{
	misc_deregister(&txx9wdt_miscdev);
	unregister_reboot_notifier(&txx9wdt_notifier);
	clk_disable(txx9_imclk);
	clk_put(txx9_imclk);
	return 0;
}

static struct platform_driver txx9wdt_driver = {
	.remove = __exit_p(txx9wdt_remove),
	.driver = {
		.name = "txx9wdt",
		.owner = THIS_MODULE,
	},
};

static int __init watchdog_init(void)
{
	return platform_driver_probe(&txx9wdt_driver, txx9wdt_probe);
}

static void __exit watchdog_exit(void)
{
	platform_driver_unregister(&txx9wdt_driver);
}

module_init(watchdog_init);
module_exit(watchdog_exit);

MODULE_DESCRIPTION("TXx9 Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:txx9wdt");
Commit	Line	Data
6f702fce AN	1	/*
	2	* txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs
	3	*
	4	* Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10	#include <linux/module.h>
	11	#include <linux/moduleparam.h>
	12	#include <linux/types.h>
	13	#include <linux/miscdevice.h>
	14	#include <linux/watchdog.h>
	15	#include <linux/fs.h>
	16	#include <linux/reboot.h>
	17	#include <linux/init.h>
	18	#include <linux/uaccess.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/clk.h>
	21	#include <linux/err.h>
	22	#include <linux/io.h>
	23	#include <asm/txx9tmr.h>
	24
	25	#define TIMER_MARGIN 60 /* Default is 60 seconds */
	26
	27	static int timeout = TIMER_MARGIN; /* in seconds */
	28	module_param(timeout, int, 0);
	29	MODULE_PARM_DESC(timeout,
	30	"Watchdog timeout in seconds. "
	31	"(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
	32	"default=" __MODULE_STRING(TIMER_MARGIN) ")");
	33
	34	static int nowayout = WATCHDOG_NOWAYOUT;
	35	module_param(nowayout, int, 0);
	36	MODULE_PARM_DESC(nowayout,
	37	"Watchdog cannot be stopped once started "
	38	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	39
	40	#define WD_TIMER_CCD 7 /* 1/256 */
	41	#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
	42	#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
	43
	44	static unsigned long txx9wdt_alive;
	45	static int expect_close;
	46	static struct txx9_tmr_reg __iomem *txx9wdt_reg;
	47	static struct clk *txx9_imclk;
f8494e06	48	static DEFINE_SPINLOCK(txx9_lock);
6f702fce AN	49
	50	static void txx9wdt_ping(void)
	51	{
8dc244f7	52	spin_lock(&txx9_lock);
6f702fce	53	__raw_writel(TXx9_TMWTMR_TWIE \| TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
8dc244f7	54	spin_unlock(&txx9_lock);
6f702fce AN	55	}
	56
	57	static void txx9wdt_start(void)
	58	{
8dc244f7	59	spin_lock(&txx9_lock);
6f702fce AN	60	__raw_writel(WD_TIMER_CLK * timeout, &txx9wdt_reg->cpra);
	61	__raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
	62	__raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */
	63	__raw_writel(TXx9_TMTCR_TCE \| TXx9_TMTCR_CCDE \| TXx9_TMTCR_TMODE_WDOG,
	64	&txx9wdt_reg->tcr);
	65	__raw_writel(TXx9_TMWTMR_TWIE \| TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
8dc244f7	66	spin_unlock(&txx9_lock);
6f702fce AN	67	}
	68
	69	static void txx9wdt_stop(void)
	70	{
8dc244f7	71	spin_lock(&txx9_lock);
6f702fce AN	72	__raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
	73	__raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
	74	&txx9wdt_reg->tcr);
8dc244f7	75	spin_unlock(&txx9_lock);
6f702fce AN	76	}
	77
	78	static int txx9wdt_open(struct inode inode, struct file file)
	79	{
	80	if (test_and_set_bit(0, &txx9wdt_alive))
	81	return -EBUSY;
	82
	83	if (__raw_readl(&txx9wdt_reg->tcr) & TXx9_TMTCR_TCE) {
	84	clear_bit(0, &txx9wdt_alive);
	85	return -EBUSY;
	86	}
	87
	88	if (nowayout)
	89	__module_get(THIS_MODULE);
	90
	91	txx9wdt_start();
	92	return nonseekable_open(inode, file);
	93	}
	94
	95	static int txx9wdt_release(struct inode inode, struct file file)
	96	{
	97	if (expect_close)
	98	txx9wdt_stop();
	99	else {
	100	printk(KERN_CRIT "txx9wdt: "
	101	"Unexpected close, not stopping watchdog!\n");
	102	txx9wdt_ping();
	103	}
	104	clear_bit(0, &txx9wdt_alive);
	105	expect_close = 0;
	106	return 0;
	107	}
	108
	109	static ssize_t txx9wdt_write(struct file file, const char __user data,
	110	size_t len, loff_t *ppos)
	111	{
	112	if (len) {
	113	if (!nowayout) {
	114	size_t i;
	115
	116	expect_close = 0;
	117	for (i = 0; i != len; i++) {
	118	char c;
	119	if (get_user(c, data + i))
	120	return -EFAULT;
	121	if (c == 'V')
	122	expect_close = 1;
	123	}
	124	}
	125	txx9wdt_ping();
	126	}
	127	return len;
	128	}
	129
8dc244f7 AC	130	static long txx9wdt_ioctl(struct file *file, unsigned int cmd,
8dc244f7 AC	131	unsigned long arg)
6f702fce AN	132	{
	133	void __user argp = (void __user )arg;
	134	int __user *p = argp;
	135	int new_timeout;
8dc244f7	136	static const struct watchdog_info ident = {
6f702fce AN	137	.options = WDIOF_SETTIMEOUT \|
	138	WDIOF_KEEPALIVEPING \|
	139	WDIOF_MAGICCLOSE,
	140	.firmware_version = 0,
	141	.identity = "Hardware Watchdog for TXx9",
	142	};
	143
	144	switch (cmd) {
6f702fce AN	145	case WDIOC_GETSUPPORT:
	146	return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	147	case WDIOC_GETSTATUS:
	148	case WDIOC_GETBOOTSTATUS:
	149	return put_user(0, p);
	150	case WDIOC_KEEPALIVE:
	151	txx9wdt_ping();
	152	return 0;
	153	case WDIOC_SETTIMEOUT:
	154	if (get_user(new_timeout, p))
	155	return -EFAULT;
	156	if (new_timeout < 1 \|\| new_timeout > WD_MAX_TIMEOUT)
	157	return -EINVAL;
	158	timeout = new_timeout;
	159	txx9wdt_stop();
	160	txx9wdt_start();
	161	/* Fall */
	162	case WDIOC_GETTIMEOUT:
	163	return put_user(timeout, p);
0c06090c WVS	164	default:
0c06090c WVS	165	return -ENOTTY;
6f702fce AN	166	}
	167	}
	168
	169	static int txx9wdt_notify_sys(struct notifier_block *this, unsigned long code,
	170	void *unused)
	171	{
	172	if (code == SYS_DOWN \|\| code == SYS_HALT)
	173	txx9wdt_stop();
	174	return NOTIFY_DONE;
	175	}
	176
	177	static const struct file_operations txx9wdt_fops = {
8dc244f7 AC	178	.owner = THIS_MODULE,
	179	.llseek = no_llseek,
	180	.write = txx9wdt_write,
	181	.unlocked_ioctl = txx9wdt_ioctl,
	182	.open = txx9wdt_open,
	183	.release = txx9wdt_release,
6f702fce AN	184	};
	185
	186	static struct miscdevice txx9wdt_miscdev = {
8dc244f7 AC	187	.minor = WATCHDOG_MINOR,
	188	.name = "watchdog",
	189	.fops = &txx9wdt_fops,
6f702fce AN	190	};
	191
	192	static struct notifier_block txx9wdt_notifier = {
7944d3a5	193	.notifier_call = txx9wdt_notify_sys,
6f702fce AN	194	};
	195
	196	static int __init txx9wdt_probe(struct platform_device *dev)
	197	{
	198	struct resource *res;
	199	int ret;
	200
	201	txx9_imclk = clk_get(NULL, "imbus_clk");
	202	if (IS_ERR(txx9_imclk)) {
	203	ret = PTR_ERR(txx9_imclk);
	204	txx9_imclk = NULL;
	205	goto exit;
	206	}
	207	ret = clk_enable(txx9_imclk);
	208	if (ret) {
	209	clk_put(txx9_imclk);
	210	txx9_imclk = NULL;
	211	goto exit;
	212	}
	213
	214	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	215	if (!res)
	216	goto exit_busy;
b782a563	217	if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
6f702fce AN	218	"txx9wdt"))
6f702fce AN	219	goto exit_busy;
b782a563	220	txx9wdt_reg = devm_ioremap(&dev->dev, res->start, resource_size(res));
6f702fce AN	221	if (!txx9wdt_reg)
	222	goto exit_busy;
	223
	224	ret = register_reboot_notifier(&txx9wdt_notifier);
	225	if (ret)
	226	goto exit;
	227
	228	ret = misc_register(&txx9wdt_miscdev);
	229	if (ret) {
	230	unregister_reboot_notifier(&txx9wdt_notifier);
	231	goto exit;
	232	}
	233
	234	printk(KERN_INFO "Hardware Watchdog Timer for TXx9: "
	235	"timeout=%d sec (max %ld) (nowayout= %d)\n",
	236	timeout, WD_MAX_TIMEOUT, nowayout);
	237
	238	return 0;
	239	exit_busy:
	240	ret = -EBUSY;
	241	exit:
	242	if (txx9_imclk) {
	243	clk_disable(txx9_imclk);
	244	clk_put(txx9_imclk);
	245	}
	246	return ret;
	247	}
	248
	249	static int __exit txx9wdt_remove(struct platform_device *dev)
	250	{
	251	misc_deregister(&txx9wdt_miscdev);
	252	unregister_reboot_notifier(&txx9wdt_notifier);
	253	clk_disable(txx9_imclk);
	254	clk_put(txx9_imclk);
	255	return 0;
	256	}
	257
	258	static struct platform_driver txx9wdt_driver = {
	259	.remove = __exit_p(txx9wdt_remove),
	260	.driver = {
	261	.name = "txx9wdt",
	262	.owner = THIS_MODULE,
	263	},
	264	};
	265
	266	static int __init watchdog_init(void)
	267	{
	268	return platform_driver_probe(&txx9wdt_driver, txx9wdt_probe);
	269	}
	270
	271	static void __exit watchdog_exit(void)
	272	{
	273	platform_driver_unregister(&txx9wdt_driver);
	274	}
	275
	276	module_init(watchdog_init);
	277	module_exit(watchdog_exit);
	278
	279	MODULE_DESCRIPTION("TXx9 Watchdog Driver");
	280	MODULE_LICENSE("GPL");
	281	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
f37d193c	282	MODULE_ALIAS("platform:txx9wdt");