[linux-2.6-block.git] / drivers / watchdog / bcm63xx_wdt.c

/*
 *  Broadcom BCM63xx SoC watchdog driver
 *
 *  Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
 *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
 *
 *  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/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/resource.h>
#include <linux/platform_device.h>

#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>
#include <bcm63xx_timer.h>

#define PFX KBUILD_MODNAME

#define WDT_HZ		50000000 /* Fclk */
#define WDT_DEFAULT_TIME	30      /* seconds */
#define WDT_MAX_TIME		256     /* seconds */

static struct {
	void __iomem *regs;
	struct timer_list timer;
	int default_ticks;
	unsigned long inuse;
	atomic_t ticks;
} bcm63xx_wdt_device;

static int expect_close;

static int wdt_time = WDT_DEFAULT_TIME;
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) ")");

/* HW functions */
static void bcm63xx_wdt_hw_start(void)
{
	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
}

static void bcm63xx_wdt_hw_stop(void)
{
	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
}

static void bcm63xx_wdt_isr(void *data)
{
	struct pt_regs *regs = get_irq_regs();

	die(PFX " fire", regs);
}

static void bcm63xx_timer_tick(unsigned long unused)
{
	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
		bcm63xx_wdt_hw_start();
		mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
	} else
		pr_crit("watchdog will restart system\n");
}

static void bcm63xx_wdt_pet(void)
{
	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
}

static void bcm63xx_wdt_start(void)
{
	bcm63xx_wdt_pet();
	bcm63xx_timer_tick(0);
}

static void bcm63xx_wdt_pause(void)
{
	del_timer_sync(&bcm63xx_wdt_device.timer);
	bcm63xx_wdt_hw_stop();
}

static int bcm63xx_wdt_settimeout(int new_time)
{
	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
		return -EINVAL;

	wdt_time = new_time;

	return 0;
}

static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
		return -EBUSY;

	bcm63xx_wdt_start();
	return nonseekable_open(inode, file);
}

static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		bcm63xx_wdt_pause();
	else {
		pr_crit("Unexpected close, not stopping watchdog!\n");
		bcm63xx_wdt_start();
	}
	clear_bit(0, &bcm63xx_wdt_device.inuse);
	expect_close = 0;
	return 0;
}

static ssize_t bcm63xx_wdt_write(struct file *file, const char *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;
			}
		}
		bcm63xx_wdt_pet();
	}
	return len;
}

static struct watchdog_info bcm63xx_wdt_info = {
	.identity       = PFX,
	.options        = WDIOF_SETTIMEOUT |
				WDIOF_KEEPALIVEPING |
				WDIOF_MAGICCLOSE,
};


static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_value, retval = -EINVAL;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &bcm63xx_wdt_info,
			sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;

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

	case WDIOC_SETOPTIONS:
		if (get_user(new_value, p))
			return -EFAULT;

		if (new_value & WDIOS_DISABLECARD) {
			bcm63xx_wdt_pause();
			retval = 0;
		}
		if (new_value & WDIOS_ENABLECARD) {
			bcm63xx_wdt_start();
			retval = 0;
		}

		return retval;

	case WDIOC_KEEPALIVE:
		bcm63xx_wdt_pet();
		return 0;

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

		if (bcm63xx_wdt_settimeout(new_value))
			return -EINVAL;

		bcm63xx_wdt_pet();

	case WDIOC_GETTIMEOUT:
		return put_user(wdt_time, p);

	default:
		return -ENOTTY;

	}
}

static const struct file_operations bcm63xx_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= bcm63xx_wdt_write,
	.unlocked_ioctl	= bcm63xx_wdt_ioctl,
	.open		= bcm63xx_wdt_open,
	.release	= bcm63xx_wdt_release,
};

static struct miscdevice bcm63xx_wdt_miscdev = {
	.minor	= WATCHDOG_MINOR,
	.name	= "watchdog",
	.fops	= &bcm63xx_wdt_fops,
};


static int bcm63xx_wdt_probe(struct platform_device *pdev)
{
	int ret;
	struct resource *r;

	setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		dev_err(&pdev->dev, "failed to get resources\n");
		return -ENODEV;
	}

	bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
							resource_size(r));
	if (!bcm63xx_wdt_device.regs) {
		dev_err(&pdev->dev, "failed to remap I/O resources\n");
		return -ENXIO;
	}

	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register wdt timer isr\n");
		return ret;
	}

	if (bcm63xx_wdt_settimeout(wdt_time)) {
		bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
		dev_info(&pdev->dev,
			": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
			wdt_time);
	}

	ret = misc_register(&bcm63xx_wdt_miscdev);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register watchdog device\n");
		goto unregister_timer;
	}

	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
						WDT_DEFAULT_TIME);

	return 0;

unregister_timer:
	bcm63xx_timer_unregister(TIMER_WDT_ID);
	return ret;
}

static int bcm63xx_wdt_remove(struct platform_device *pdev)
{
	if (!nowayout)
		bcm63xx_wdt_pause();

	misc_deregister(&bcm63xx_wdt_miscdev);
	bcm63xx_timer_unregister(TIMER_WDT_ID);
	return 0;
}

static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
{
	bcm63xx_wdt_pause();
}

static struct platform_driver bcm63xx_wdt_driver = {
	.probe	= bcm63xx_wdt_probe,
	.remove = bcm63xx_wdt_remove,
	.shutdown = bcm63xx_wdt_shutdown,
	.driver = {
		.owner = THIS_MODULE,
		.name = "bcm63xx-wdt",
	}
};

module_platform_driver(bcm63xx_wdt_driver);

MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:bcm63xx-wdt");
Commit	Line	Data
b63aa731 FF	1	/*
	2	* Broadcom BCM63xx SoC watchdog driver
	3	*
	4	* Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
	5	* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
27c766aa JP	13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	14
b63aa731 FF	15	#include <linux/bitops.h>
	16	#include <linux/errno.h>
	17	#include <linux/fs.h>
	18	#include <linux/init.h>
626d65aa	19	#include <linux/io.h>
b63aa731 FF	20	#include <linux/kernel.h>
	21	#include <linux/miscdevice.h>
	22	#include <linux/module.h>
	23	#include <linux/moduleparam.h>
b63aa731 FF	24	#include <linux/types.h>
	25	#include <linux/uaccess.h>
	26	#include <linux/watchdog.h>
	27	#include <linux/timer.h>
	28	#include <linux/jiffies.h>
	29	#include <linux/interrupt.h>
	30	#include <linux/ptrace.h>
	31	#include <linux/resource.h>
	32	#include <linux/platform_device.h>
	33
	34	#include <bcm63xx_cpu.h>
	35	#include <bcm63xx_io.h>
	36	#include <bcm63xx_regs.h>
	37	#include <bcm63xx_timer.h>
	38
	39	#define PFX KBUILD_MODNAME
	40
	41	#define WDT_HZ 50000000 /* Fclk */
	42	#define WDT_DEFAULT_TIME 30 /* seconds */
	43	#define WDT_MAX_TIME 256 /* seconds */
	44
	45	static struct {
	46	void __iomem *regs;
	47	struct timer_list timer;
	48	int default_ticks;
	49	unsigned long inuse;
	50	atomic_t ticks;
	51	} bcm63xx_wdt_device;
	52
	53	static int expect_close;
	54
	55	static int wdt_time = WDT_DEFAULT_TIME;
86a1e189 WVS	56	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	57	module_param(nowayout, bool, 0);
b63aa731 FF	58	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	59	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	60
	61	/* HW functions */
	62	static void bcm63xx_wdt_hw_start(void)
	63	{
	64	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
	65	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	66	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	67	}
	68
	69	static void bcm63xx_wdt_hw_stop(void)
	70	{
	71	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	72	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	73	}
	74
	75	static void bcm63xx_wdt_isr(void *data)
	76	{
	77	struct pt_regs *regs = get_irq_regs();
	78
	79	die(PFX " fire", regs);
	80	}
	81
	82	static void bcm63xx_timer_tick(unsigned long unused)
	83	{
	84	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
	85	bcm63xx_wdt_hw_start();
	86	mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
	87	} else
27c766aa	88	pr_crit("watchdog will restart system\n");
b63aa731 FF	89	}
	90
	91	static void bcm63xx_wdt_pet(void)
	92	{
	93	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
	94	}
	95
	96	static void bcm63xx_wdt_start(void)
	97	{
	98	bcm63xx_wdt_pet();
	99	bcm63xx_timer_tick(0);
	100	}
	101
	102	static void bcm63xx_wdt_pause(void)
	103	{
	104	del_timer_sync(&bcm63xx_wdt_device.timer);
	105	bcm63xx_wdt_hw_stop();
	106	}
	107
	108	static int bcm63xx_wdt_settimeout(int new_time)
	109	{
	110	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
	111	return -EINVAL;
	112
	113	wdt_time = new_time;
	114
	115	return 0;
	116	}
	117
	118	static int bcm63xx_wdt_open(struct inode inode, struct file file)
	119	{
	120	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
	121	return -EBUSY;
	122
	123	bcm63xx_wdt_start();
	124	return nonseekable_open(inode, file);
	125	}
	126
	127	static int bcm63xx_wdt_release(struct inode inode, struct file file)
	128	{
	129	if (expect_close == 42)
	130	bcm63xx_wdt_pause();
	131	else {
27c766aa	132	pr_crit("Unexpected close, not stopping watchdog!\n");
b63aa731 FF	133	bcm63xx_wdt_start();
	134	}
	135	clear_bit(0, &bcm63xx_wdt_device.inuse);
	136	expect_close = 0;
	137	return 0;
	138	}
	139
	140	static ssize_t bcm63xx_wdt_write(struct file file, const char data,
	141	size_t len, loff_t *ppos)
	142	{
	143	if (len) {
	144	if (!nowayout) {
	145	size_t i;
	146
	147	/* In case it was set long ago */
	148	expect_close = 0;
	149
	150	for (i = 0; i != len; i++) {
	151	char c;
	152	if (get_user(c, data + i))
	153	return -EFAULT;
	154	if (c == 'V')
	155	expect_close = 42;
	156	}
	157	}
	158	bcm63xx_wdt_pet();
	159	}
	160	return len;
	161	}
	162
	163	static struct watchdog_info bcm63xx_wdt_info = {
	164	.identity = PFX,
	165	.options = WDIOF_SETTIMEOUT \|
	166	WDIOF_KEEPALIVEPING \|
	167	WDIOF_MAGICCLOSE,
	168	};
	169
	170
	171	static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
	172	unsigned long arg)
	173	{
	174	void __user argp = (void __user )arg;
	175	int __user *p = argp;
	176	int new_value, retval = -EINVAL;
	177
	178	switch (cmd) {
	179	case WDIOC_GETSUPPORT:
	180	return copy_to_user(argp, &bcm63xx_wdt_info,
	181	sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
	182
	183	case WDIOC_GETSTATUS:
	184	case WDIOC_GETBOOTSTATUS:
	185	return put_user(0, p);
	186
	187	case WDIOC_SETOPTIONS:
	188	if (get_user(new_value, p))
	189	return -EFAULT;
	190
	191	if (new_value & WDIOS_DISABLECARD) {
	192	bcm63xx_wdt_pause();
	193	retval = 0;
	194	}
	195	if (new_value & WDIOS_ENABLECARD) {
	196	bcm63xx_wdt_start();
197	retval = 0;
198	}
199
200	return retval;
201
202	case WDIOC_KEEPALIVE:
203	bcm63xx_wdt_pet();
204	return 0;
205
206	case WDIOC_SETTIMEOUT:
207	if (get_user(new_value, p))
208	return -EFAULT;
209
210	if (bcm63xx_wdt_settimeout(new_value))
211	return -EINVAL;
212
213	bcm63xx_wdt_pet();
214
215	case WDIOC_GETTIMEOUT:
216	return put_user(wdt_time, p);
217
218	default:
219	return -ENOTTY;
220
221	}
222	}
223
b63aa731 FF	224	static const struct file_operations bcm63xx_wdt_fops = {
	225	.owner = THIS_MODULE,
	226	.llseek = no_llseek,
	227	.write = bcm63xx_wdt_write,
	228	.unlocked_ioctl = bcm63xx_wdt_ioctl,
	229	.open = bcm63xx_wdt_open,
	230	.release = bcm63xx_wdt_release,
	231	};
	232
	233	static struct miscdevice bcm63xx_wdt_miscdev = {
	234	.minor = WATCHDOG_MINOR,
	235	.name = "watchdog",
	236	.fops = &bcm63xx_wdt_fops,
	237	};
	238
b63aa731	239
2d991a16	240	static int bcm63xx_wdt_probe(struct platform_device *pdev)
b63aa731 FF	241	{
	242	int ret;
	243	struct resource *r;
	244
	245	setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
	246
	247	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	248	if (!r) {
	249	dev_err(&pdev->dev, "failed to get resources\n");
	250	return -ENODEV;
	251	}
	252
626d65aa JH	253	bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
626d65aa JH	254	resource_size(r));
b63aa731 FF	255	if (!bcm63xx_wdt_device.regs) {
	256	dev_err(&pdev->dev, "failed to remap I/O resources\n");
	257	return -ENXIO;
	258	}
	259
	260	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
	261	if (ret < 0) {
	262	dev_err(&pdev->dev, "failed to register wdt timer isr\n");
626d65aa	263	return ret;
b63aa731 FF	264	}
	265
	266	if (bcm63xx_wdt_settimeout(wdt_time)) {
	267	bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
	268	dev_info(&pdev->dev,
	269	": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
	270	wdt_time);
	271	}
	272
b63aa731 FF	273	ret = misc_register(&bcm63xx_wdt_miscdev);
	274	if (ret < 0) {
	275	dev_err(&pdev->dev, "failed to register watchdog device\n");
e6c3b699	276	goto unregister_timer;
b63aa731 FF	277	}
	278
	279	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
	280	WDT_DEFAULT_TIME);
	281
	282	return 0;
	283
b63aa731 FF	284	unregister_timer:
b63aa731 FF	285	bcm63xx_timer_unregister(TIMER_WDT_ID);
b63aa731 FF	286	return ret;
	287	}
	288
4b12b896	289	static int bcm63xx_wdt_remove(struct platform_device *pdev)
b63aa731 FF	290	{
	291	if (!nowayout)
	292	bcm63xx_wdt_pause();
	293
	294	misc_deregister(&bcm63xx_wdt_miscdev);
b63aa731	295	bcm63xx_timer_unregister(TIMER_WDT_ID);
b63aa731 FF	296	return 0;
	297	}
	298
e6c3b699 WVS	299	static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
	300	{
	301	bcm63xx_wdt_pause();
	302	}
	303
5a135f3c	304	static struct platform_driver bcm63xx_wdt_driver = {
b63aa731	305	.probe = bcm63xx_wdt_probe,
82268714	306	.remove = bcm63xx_wdt_remove,
e6c3b699	307	.shutdown = bcm63xx_wdt_shutdown,
b63aa731	308	.driver = {
e6c3b699	309	.owner = THIS_MODULE,
b63aa731 FF	310	.name = "bcm63xx-wdt",
	311	}
	312	};
	313
5a135f3c	314	module_platform_driver(bcm63xx_wdt_driver);
b63aa731 FF	315
	316	MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
	317	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	318	MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
	319	MODULE_LICENSE("GPL");
	320	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	321	MODULE_ALIAS("platform:bcm63xx-wdt");