[mirror_ubuntu-bionic-kernel.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.
 */

#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.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 int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 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
		printk(KERN_CRIT PFX ": 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 {
		printk(KERN_CRIT PFX
			": 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 __devinit 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 = ioremap_nocache(r->start, r->end - r->start);
	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");
		goto unmap;
	}

	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);
unmap:
	iounmap(bcm63xx_wdt_device.regs);
	return ret;
}

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

	misc_deregister(&bcm63xx_wdt_miscdev);
	bcm63xx_timer_unregister(TIMER_WDT_ID);
	iounmap(bcm63xx_wdt_device.regs);
	return 0;
}

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

static struct platform_driver bcm63xx_wdt = {
	.probe	= bcm63xx_wdt_probe,
	.remove = __devexit_p(bcm63xx_wdt_remove),
	.shutdown = bcm63xx_wdt_shutdown,
	.driver = {
		.owner = THIS_MODULE,
		.name = "bcm63xx-wdt",
	}
};

static int __init bcm63xx_wdt_init(void)
{
	return platform_driver_register(&bcm63xx_wdt);
}

static void __exit bcm63xx_wdt_exit(void)
{
	platform_driver_unregister(&bcm63xx_wdt);
}

module_init(bcm63xx_wdt_init);
module_exit(bcm63xx_wdt_exit);

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
	13	#include <linux/bitops.h>
	14	#include <linux/errno.h>
	15	#include <linux/fs.h>
	16	#include <linux/init.h>
	17	#include <linux/kernel.h>
	18	#include <linux/miscdevice.h>
	19	#include <linux/module.h>
	20	#include <linux/moduleparam.h>
b63aa731 FF	21	#include <linux/types.h>
	22	#include <linux/uaccess.h>
	23	#include <linux/watchdog.h>
	24	#include <linux/timer.h>
	25	#include <linux/jiffies.h>
	26	#include <linux/interrupt.h>
	27	#include <linux/ptrace.h>
	28	#include <linux/resource.h>
	29	#include <linux/platform_device.h>
	30
	31	#include <bcm63xx_cpu.h>
	32	#include <bcm63xx_io.h>
	33	#include <bcm63xx_regs.h>
	34	#include <bcm63xx_timer.h>
	35
	36	#define PFX KBUILD_MODNAME
	37
	38	#define WDT_HZ 50000000 /* Fclk */
	39	#define WDT_DEFAULT_TIME 30 /* seconds */
	40	#define WDT_MAX_TIME 256 /* seconds */
	41
	42	static struct {
	43	void __iomem *regs;
	44	struct timer_list timer;
	45	int default_ticks;
	46	unsigned long inuse;
	47	atomic_t ticks;
	48	} bcm63xx_wdt_device;
	49
	50	static int expect_close;
	51
	52	static int wdt_time = WDT_DEFAULT_TIME;
	53	static int nowayout = WATCHDOG_NOWAYOUT;
	54	module_param(nowayout, int, 0);
	55	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	56	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	57
	58	/* HW functions */
	59	static void bcm63xx_wdt_hw_start(void)
	60	{
	61	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
	62	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	63	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	64	}
	65
	66	static void bcm63xx_wdt_hw_stop(void)
	67	{
	68	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	69	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
	70	}
	71
	72	static void bcm63xx_wdt_isr(void *data)
	73	{
	74	struct pt_regs *regs = get_irq_regs();
	75
	76	die(PFX " fire", regs);
	77	}
	78
	79	static void bcm63xx_timer_tick(unsigned long unused)
	80	{
	81	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
	82	bcm63xx_wdt_hw_start();
	83	mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
	84	} else
85	printk(KERN_CRIT PFX ": watchdog will restart system\n");
86	}
87
88	static void bcm63xx_wdt_pet(void)
89	{
90	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
91	}
92
93	static void bcm63xx_wdt_start(void)
94	{
95	bcm63xx_wdt_pet();
96	bcm63xx_timer_tick(0);
97	}
98
99	static void bcm63xx_wdt_pause(void)
100	{
101	del_timer_sync(&bcm63xx_wdt_device.timer);
102	bcm63xx_wdt_hw_stop();
103	}
104
105	static int bcm63xx_wdt_settimeout(int new_time)
106	{
107	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
108	return -EINVAL;
109
110	wdt_time = new_time;
111
112	return 0;
113	}
114
115	static int bcm63xx_wdt_open(struct inode inode, struct file file)
116	{
117	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
118	return -EBUSY;
119
120	bcm63xx_wdt_start();
121	return nonseekable_open(inode, file);
122	}
123
124	static int bcm63xx_wdt_release(struct inode inode, struct file file)
125	{
126	if (expect_close == 42)
127	bcm63xx_wdt_pause();
128	else {
129	printk(KERN_CRIT PFX
130	": Unexpected close, not stopping watchdog!\n");
131	bcm63xx_wdt_start();
132	}
133	clear_bit(0, &bcm63xx_wdt_device.inuse);
134	expect_close = 0;
135	return 0;
136	}
137
138	static ssize_t bcm63xx_wdt_write(struct file file, const char data,
139	size_t len, loff_t *ppos)
140	{
141	if (len) {
142	if (!nowayout) {
143	size_t i;
144
145	/* In case it was set long ago */
146	expect_close = 0;
147
148	for (i = 0; i != len; i++) {
149	char c;
150	if (get_user(c, data + i))
151	return -EFAULT;
152	if (c == 'V')
153	expect_close = 42;
154	}
155	}
156	bcm63xx_wdt_pet();
157	}
158	return len;
159	}
160
161	static struct watchdog_info bcm63xx_wdt_info = {
162	.identity = PFX,
163	.options = WDIOF_SETTIMEOUT \|
164	WDIOF_KEEPALIVEPING \|
165	WDIOF_MAGICCLOSE,
166	};
167
168
169	static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
170	unsigned long arg)
171	{
172	void __user argp = (void __user )arg;
173	int __user *p = argp;
174	int new_value, retval = -EINVAL;
175
176	switch (cmd) {
177	case WDIOC_GETSUPPORT:
178	return copy_to_user(argp, &bcm63xx_wdt_info,
179	sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
180
181	case WDIOC_GETSTATUS:
182	case WDIOC_GETBOOTSTATUS:
183	return put_user(0, p);
184
185	case WDIOC_SETOPTIONS:
186	if (get_user(new_value, p))
187	return -EFAULT;
188
189	if (new_value & WDIOS_DISABLECARD) {
190	bcm63xx_wdt_pause();
191	retval = 0;
192	}
193	if (new_value & WDIOS_ENABLECARD) {
194	bcm63xx_wdt_start();
195	retval = 0;
196	}
197
198	return retval;
199
200	case WDIOC_KEEPALIVE:
201	bcm63xx_wdt_pet();
202	return 0;
203
204	case WDIOC_SETTIMEOUT:
205	if (get_user(new_value, p))
206	return -EFAULT;
207
208	if (bcm63xx_wdt_settimeout(new_value))
209	return -EINVAL;
210
211	bcm63xx_wdt_pet();
212
213	case WDIOC_GETTIMEOUT:
214	return put_user(wdt_time, p);
215
216	default:
217	return -ENOTTY;
218
219	}
220	}
221
b63aa731 FF	222	static const struct file_operations bcm63xx_wdt_fops = {
	223	.owner = THIS_MODULE,
	224	.llseek = no_llseek,
	225	.write = bcm63xx_wdt_write,
	226	.unlocked_ioctl = bcm63xx_wdt_ioctl,
	227	.open = bcm63xx_wdt_open,
	228	.release = bcm63xx_wdt_release,
	229	};
	230
	231	static struct miscdevice bcm63xx_wdt_miscdev = {
	232	.minor = WATCHDOG_MINOR,
	233	.name = "watchdog",
	234	.fops = &bcm63xx_wdt_fops,
	235	};
	236
b63aa731	237
e6c3b699	238	static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev)
b63aa731 FF	239	{
	240	int ret;
	241	struct resource *r;
	242
	243	setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
	244
	245	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	246	if (!r) {
	247	dev_err(&pdev->dev, "failed to get resources\n");
	248	return -ENODEV;
	249	}
	250
	251	bcm63xx_wdt_device.regs = ioremap_nocache(r->start, r->end - r->start);
	252	if (!bcm63xx_wdt_device.regs) {
	253	dev_err(&pdev->dev, "failed to remap I/O resources\n");
	254	return -ENXIO;
	255	}
	256
	257	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
	258	if (ret < 0) {
	259	dev_err(&pdev->dev, "failed to register wdt timer isr\n");
	260	goto unmap;
	261	}
	262
	263	if (bcm63xx_wdt_settimeout(wdt_time)) {
	264	bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
	265	dev_info(&pdev->dev,
	266	": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
	267	wdt_time);
	268	}
	269
b63aa731 FF	270	ret = misc_register(&bcm63xx_wdt_miscdev);
	271	if (ret < 0) {
	272	dev_err(&pdev->dev, "failed to register watchdog device\n");
e6c3b699	273	goto unregister_timer;
b63aa731 FF	274	}
	275
	276	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
	277	WDT_DEFAULT_TIME);
	278
	279	return 0;
	280
b63aa731 FF	281	unregister_timer:
	282	bcm63xx_timer_unregister(TIMER_WDT_ID);
	283	unmap:
	284	iounmap(bcm63xx_wdt_device.regs);
	285	return ret;
	286	}
	287
e6c3b699	288	static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev)
b63aa731 FF	289	{
	290	if (!nowayout)
	291	bcm63xx_wdt_pause();
	292
	293	misc_deregister(&bcm63xx_wdt_miscdev);
b63aa731	294	bcm63xx_timer_unregister(TIMER_WDT_ID);
e6c3b699	295	iounmap(bcm63xx_wdt_device.regs);
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
b63aa731 FF	304	static struct platform_driver bcm63xx_wdt = {
b63aa731 FF	305	.probe = bcm63xx_wdt_probe,
e6c3b699 WVS	306	.remove = __devexit_p(bcm63xx_wdt_remove),
e6c3b699 WVS	307	.shutdown = bcm63xx_wdt_shutdown,
b63aa731	308	.driver = {
e6c3b699	309	.owner = THIS_MODULE,
b63aa731 FF	310	.name = "bcm63xx-wdt",
	311	}
	312	};
	313
	314	static int __init bcm63xx_wdt_init(void)
	315	{
	316	return platform_driver_register(&bcm63xx_wdt);
	317	}
	318
	319	static void __exit bcm63xx_wdt_exit(void)
	320	{
	321	platform_driver_unregister(&bcm63xx_wdt);
	322	}
	323
	324	module_init(bcm63xx_wdt_init);
	325	module_exit(bcm63xx_wdt_exit);
	326
	327	MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
	328	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	329	MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
	330	MODULE_LICENSE("GPL");
	331	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	332	MODULE_ALIAS("platform:bcm63xx-wdt");