[linux-2.6-block.git] / drivers / watchdog / orion5x_wdt.c

/*
 * drivers/watchdog/orion5x_wdt.c
 *
 * Watchdog driver for Orion5x processors
 *
 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
 *
 * This file is licensed under  the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <plat/orion5x_wdt.h>

/*
 * Watchdog timer block registers.
 */
#define TIMER_CTRL		(TIMER_VIRT_BASE + 0x0000)
#define  WDT_EN			0x0010
#define WDT_VAL			(TIMER_VIRT_BASE + 0x0024)

#define WDT_MAX_CYCLE_COUNT	0xffffffff
#define WDT_IN_USE		0
#define WDT_OK_TO_CLOSE		1

static int nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = -1;		/* module parameter (seconds) */
static unsigned int wdt_max_duration;	/* (seconds) */
static unsigned int wdt_tclk;
static unsigned long wdt_status;
static spinlock_t wdt_lock;

static void orion5x_wdt_ping(void)
{
	spin_lock(&wdt_lock);

	/* Reload watchdog duration */
	writel(wdt_tclk * heartbeat, WDT_VAL);

	spin_unlock(&wdt_lock);
}

static void orion5x_wdt_enable(void)
{
	u32 reg;

	spin_lock(&wdt_lock);

	/* Set watchdog duration */
	writel(wdt_tclk * heartbeat, WDT_VAL);

	/* Clear watchdog timer interrupt */
	reg = readl(BRIDGE_CAUSE);
	reg &= ~WDT_INT_REQ;
	writel(reg, BRIDGE_CAUSE);

	/* Enable watchdog timer */
	reg = readl(TIMER_CTRL);
	reg |= WDT_EN;
	writel(reg, TIMER_CTRL);

	/* Enable reset on watchdog */
	reg = readl(CPU_RESET_MASK);
	reg |= WDT_RESET;
	writel(reg, CPU_RESET_MASK);

	spin_unlock(&wdt_lock);
}

static void orion5x_wdt_disable(void)
{
	u32 reg;

	spin_lock(&wdt_lock);

	/* Disable reset on watchdog */
	reg = readl(CPU_RESET_MASK);
	reg &= ~WDT_RESET;
	writel(reg, CPU_RESET_MASK);

	/* Disable watchdog timer */
	reg = readl(TIMER_CTRL);
	reg &= ~WDT_EN;
	writel(reg, TIMER_CTRL);

	spin_unlock(&wdt_lock);
}

static int orion5x_wdt_get_timeleft(int *time_left)
{
	spin_lock(&wdt_lock);
	*time_left = readl(WDT_VAL) / wdt_tclk;
	spin_unlock(&wdt_lock);
	return 0;
}

static int orion5x_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
		return -EBUSY;
	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	orion5x_wdt_enable();
	return nonseekable_open(inode, file);
}

static ssize_t orion5x_wdt_write(struct file *file, const char *data,
					size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					set_bit(WDT_OK_TO_CLOSE, &wdt_status);
			}
		}
		orion5x_wdt_ping();
	}
	return len;
}

static int orion5x_wdt_settimeout(int new_time)
{
	if ((new_time <= 0) || (new_time > wdt_max_duration))
		return -EINVAL;

	/* Set new watchdog time to be used when
	 * orion5x_wdt_enable() or orion5x_wdt_ping() is called. */
	heartbeat = new_time;
	return 0;
}

static const struct watchdog_info ident = {
	.options	= WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
			  WDIOF_KEEPALIVEPING,
	.identity	= "Orion5x Watchdog",
};

static long orion5x_wdt_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg)
{
	int ret = -ENOTTY;
	int time;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = copy_to_user((struct watchdog_info *)arg, &ident,
				   sizeof(ident)) ? -EFAULT : 0;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		ret = put_user(0, (int *)arg);
		break;

	case WDIOC_KEEPALIVE:
		orion5x_wdt_ping();
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(time, (int *)arg);
		if (ret)
			break;

		if (orion5x_wdt_settimeout(time)) {
			ret = -EINVAL;
			break;
		}
		orion5x_wdt_ping();
		/* Fall through */

	case WDIOC_GETTIMEOUT:
		ret = put_user(heartbeat, (int *)arg);
		break;

	case WDIOC_GETTIMELEFT:
		if (orion5x_wdt_get_timeleft(&time)) {
			ret = -EINVAL;
			break;
		}
		ret = put_user(time, (int *)arg);
		break;
	}
	return ret;
}

static int orion5x_wdt_release(struct inode *inode, struct file *file)
{
	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
		orion5x_wdt_disable();
	else
		printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
					"timer will not stop\n");
	clear_bit(WDT_IN_USE, &wdt_status);
	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

	return 0;
}


static const struct file_operations orion5x_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= orion5x_wdt_write,
	.unlocked_ioctl	= orion5x_wdt_ioctl,
	.open		= orion5x_wdt_open,
	.release	= orion5x_wdt_release,
};

static struct miscdevice orion5x_wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &orion5x_wdt_fops,
};

static int __devinit orion5x_wdt_probe(struct platform_device *pdev)
{
	struct orion5x_wdt_platform_data *pdata = pdev->dev.platform_data;
	int ret;

	if (pdata) {
		wdt_tclk = pdata->tclk;
	} else {
		printk(KERN_ERR "Orion5x Watchdog misses platform data\n");
		return -ENODEV;
	}

	if (orion5x_wdt_miscdev.parent)
		return -EBUSY;
	orion5x_wdt_miscdev.parent = &pdev->dev;

	wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
	if (orion5x_wdt_settimeout(heartbeat))
		heartbeat = wdt_max_duration;

	ret = misc_register(&orion5x_wdt_miscdev);
	if (ret)
		return ret;

	printk(KERN_INFO "Orion5x Watchdog Timer: Initial timeout %d sec%s\n",
				heartbeat, nowayout ? ", nowayout" : "");
	return 0;
}

static int __devexit orion5x_wdt_remove(struct platform_device *pdev)
{
	int ret;

	if (test_bit(WDT_IN_USE, &wdt_status)) {
		orion5x_wdt_disable();
		clear_bit(WDT_IN_USE, &wdt_status);
	}

	ret = misc_deregister(&orion5x_wdt_miscdev);
	if (!ret)
		orion5x_wdt_miscdev.parent = NULL;

	return ret;
}

static void orion5x_wdt_shutdown(struct platform_device *pdev)
{
	if (test_bit(WDT_IN_USE, &wdt_status))
		orion5x_wdt_disable();
}

static struct platform_driver orion5x_wdt_driver = {
	.probe		= orion5x_wdt_probe,
	.remove		= __devexit_p(orion5x_wdt_remove),
	.shutdown	= orion5x_wdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "orion5x_wdt",
	},
};

static int __init orion5x_wdt_init(void)
{
	spin_lock_init(&wdt_lock);
	return platform_driver_register(&orion5x_wdt_driver);
}

static void __exit orion5x_wdt_exit(void)
{
	platform_driver_unregister(&orion5x_wdt_driver);
}

module_init(orion5x_wdt_init);
module_exit(orion5x_wdt_exit);

MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
MODULE_DESCRIPTION("Orion5x Processor Watchdog");

module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
22ac9232 SB	1	/*
	2	* drivers/watchdog/orion5x_wdt.c
	3	*
	4	* Watchdog driver for Orion5x processors
	5	*
	6	* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
	7	*
	8	* This file is licensed under the terms of the GNU General Public
	9	* License version 2. This program is licensed "as is" without any
	10	* warranty of any kind, whether express or implied.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/moduleparam.h>
	15	#include <linux/types.h>
	16	#include <linux/kernel.h>
	17	#include <linux/fs.h>
	18	#include <linux/miscdevice.h>
9e058d4f	19	#include <linux/platform_device.h>
22ac9232 SB	20	#include <linux/watchdog.h>
	21	#include <linux/init.h>
	22	#include <linux/uaccess.h>
	23	#include <linux/io.h>
6d0f0dfd	24	#include <linux/spinlock.h>
9e058d4f	25	#include <plat/orion5x_wdt.h>
22ac9232 SB	26
	27	/*
	28	* Watchdog timer block registers.
	29	*/
	30	#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
	31	#define WDT_EN 0x0010
	32	#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
	33
9e058d4f	34	#define WDT_MAX_CYCLE_COUNT 0xffffffff
22ac9232 SB	35	#define WDT_IN_USE 0
	36	#define WDT_OK_TO_CLOSE 1
	37
	38	static int nowayout = WATCHDOG_NOWAYOUT;
9e058d4f TR	39	static int heartbeat = -1; /* module parameter (seconds) */
	40	static unsigned int wdt_max_duration; /* (seconds) */
	41	static unsigned int wdt_tclk;
22ac9232	42	static unsigned long wdt_status;
6d0f0dfd	43	static spinlock_t wdt_lock;
22ac9232	44
df6707b2 TR	45	static void orion5x_wdt_ping(void)
	46	{
	47	spin_lock(&wdt_lock);
	48
	49	/* Reload watchdog duration */
	50	writel(wdt_tclk * heartbeat, WDT_VAL);
	51
	52	spin_unlock(&wdt_lock);
	53	}
	54
	55	static void orion5x_wdt_enable(void)
22ac9232 SB	56	{
	57	u32 reg;
	58
6d0f0dfd WVS	59	spin_lock(&wdt_lock);
6d0f0dfd WVS	60
22ac9232	61	/* Set watchdog duration */
9e058d4f	62	writel(wdt_tclk * heartbeat, WDT_VAL);
22ac9232 SB	63
	64	/* Clear watchdog timer interrupt */
	65	reg = readl(BRIDGE_CAUSE);
	66	reg &= ~WDT_INT_REQ;
	67	writel(reg, BRIDGE_CAUSE);
	68
	69	/* Enable watchdog timer */
	70	reg = readl(TIMER_CTRL);
	71	reg \|= WDT_EN;
	72	writel(reg, TIMER_CTRL);
	73
	74	/* Enable reset on watchdog */
	75	reg = readl(CPU_RESET_MASK);
	76	reg \|= WDT_RESET;
	77	writel(reg, CPU_RESET_MASK);
6d0f0dfd WVS	78
6d0f0dfd WVS	79	spin_unlock(&wdt_lock);
22ac9232 SB	80	}
22ac9232 SB	81
df6707b2	82	static void orion5x_wdt_disable(void)
22ac9232 SB	83	{
	84	u32 reg;
	85
6d0f0dfd WVS	86	spin_lock(&wdt_lock);
6d0f0dfd WVS	87
22ac9232 SB	88	/* Disable reset on watchdog */
	89	reg = readl(CPU_RESET_MASK);
	90	reg &= ~WDT_RESET;
	91	writel(reg, CPU_RESET_MASK);
	92
	93	/* Disable watchdog timer */
	94	reg = readl(TIMER_CTRL);
	95	reg &= ~WDT_EN;
	96	writel(reg, TIMER_CTRL);
6d0f0dfd WVS	97
	98	spin_unlock(&wdt_lock);
	99	}
	100
	101	static int orion5x_wdt_get_timeleft(int *time_left)
	102	{
	103	spin_lock(&wdt_lock);
9e058d4f	104	*time_left = readl(WDT_VAL) / wdt_tclk;
6d0f0dfd WVS	105	spin_unlock(&wdt_lock);
6d0f0dfd WVS	106	return 0;
22ac9232 SB	107	}
	108
	109	static int orion5x_wdt_open(struct inode inode, struct file file)
	110	{
	111	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
	112	return -EBUSY;
	113	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
df6707b2	114	orion5x_wdt_enable();
22ac9232 SB	115	return nonseekable_open(inode, file);
	116	}
	117
22ac9232 SB	118	static ssize_t orion5x_wdt_write(struct file file, const char data,
	119	size_t len, loff_t *ppos)
	120	{
	121	if (len) {
	122	if (!nowayout) {
	123	size_t i;
	124
	125	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	126	for (i = 0; i != len; i++) {
	127	char c;
	128
	129	if (get_user(c, data + i))
	130	return -EFAULT;
	131	if (c == 'V')
	132	set_bit(WDT_OK_TO_CLOSE, &wdt_status);
	133	}
	134	}
df6707b2	135	orion5x_wdt_ping();
22ac9232 SB	136	}
	137	return len;
	138	}
	139
df6707b2 TR	140	static int orion5x_wdt_settimeout(int new_time)
	141	{
	142	if ((new_time <= 0) \|\| (new_time > wdt_max_duration))
	143	return -EINVAL;
	144
	145	/* Set new watchdog time to be used when
	146	* orion5x_wdt_enable() or orion5x_wdt_ping() is called. */
	147	heartbeat = new_time;
	148	return 0;
	149	}
	150
	151	static const struct watchdog_info ident = {
22ac9232 SB	152	.options = WDIOF_MAGICCLOSE \| WDIOF_SETTIMEOUT \|
	153	WDIOF_KEEPALIVEPING,
	154	.identity = "Orion5x Watchdog",
	155	};
	156
22ac9232 SB	157	static long orion5x_wdt_ioctl(struct file *file, unsigned int cmd,
	158	unsigned long arg)
	159	{
	160	int ret = -ENOTTY;
	161	int time;
	162
	163	switch (cmd) {
	164	case WDIOC_GETSUPPORT:
	165	ret = copy_to_user((struct watchdog_info *)arg, &ident,
	166	sizeof(ident)) ? -EFAULT : 0;
	167	break;
	168
	169	case WDIOC_GETSTATUS:
	170	case WDIOC_GETBOOTSTATUS:
	171	ret = put_user(0, (int *)arg);
	172	break;
	173
	174	case WDIOC_KEEPALIVE:
df6707b2	175	orion5x_wdt_ping();
22ac9232 SB	176	ret = 0;
	177	break;
	178
	179	case WDIOC_SETTIMEOUT:
	180	ret = get_user(time, (int *)arg);
	181	if (ret)
	182	break;
	183
df6707b2	184	if (orion5x_wdt_settimeout(time)) {
22ac9232 SB	185	ret = -EINVAL;
	186	break;
	187	}
df6707b2	188	orion5x_wdt_ping();
22ac9232 SB	189	/* Fall through */
	190
	191	case WDIOC_GETTIMEOUT:
	192	ret = put_user(heartbeat, (int *)arg);
	193	break;
	194
	195	case WDIOC_GETTIMELEFT:
	196	if (orion5x_wdt_get_timeleft(&time)) {
	197	ret = -EINVAL;
	198	break;
	199	}
	200	ret = put_user(time, (int *)arg);
	201	break;
	202	}
	203	return ret;
	204	}
	205
	206	static int orion5x_wdt_release(struct inode inode, struct file file)
	207	{
	208	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
df6707b2	209	orion5x_wdt_disable();
22ac9232 SB	210	else
	211	printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
	212	"timer will not stop\n");
	213	clear_bit(WDT_IN_USE, &wdt_status);
	214	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	215
	216	return 0;
	217	}
	218
	219
	220	static const struct file_operations orion5x_wdt_fops = {
	221	.owner = THIS_MODULE,
	222	.llseek = no_llseek,
	223	.write = orion5x_wdt_write,
	224	.unlocked_ioctl = orion5x_wdt_ioctl,
	225	.open = orion5x_wdt_open,
	226	.release = orion5x_wdt_release,
	227	};
	228
	229	static struct miscdevice orion5x_wdt_miscdev = {
	230	.minor = WATCHDOG_MINOR,
	231	.name = "watchdog",
	232	.fops = &orion5x_wdt_fops,
	233	};
	234
9e058d4f	235	static int __devinit orion5x_wdt_probe(struct platform_device *pdev)
22ac9232	236	{
9e058d4f	237	struct orion5x_wdt_platform_data *pdata = pdev->dev.platform_data;
22ac9232 SB	238	int ret;
22ac9232 SB	239
9e058d4f TR	240	if (pdata) {
	241	wdt_tclk = pdata->tclk;
	242	} else {
	243	printk(KERN_ERR "Orion5x Watchdog misses platform data\n");
	244	return -ENODEV;
	245	}
	246
	247	if (orion5x_wdt_miscdev.parent)
	248	return -EBUSY;
	249	orion5x_wdt_miscdev.parent = &pdev->dev;
	250
	251	wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
df6707b2	252	if (orion5x_wdt_settimeout(heartbeat))
9e058d4f	253	heartbeat = wdt_max_duration;
6d0f0dfd	254
22ac9232	255	ret = misc_register(&orion5x_wdt_miscdev);
9e058d4f TR	256	if (ret)
	257	return ret;
	258
	259	printk(KERN_INFO "Orion5x Watchdog Timer: Initial timeout %d sec%s\n",
	260	heartbeat, nowayout ? ", nowayout" : "");
	261	return 0;
	262	}
	263
	264	static int __devexit orion5x_wdt_remove(struct platform_device *pdev)
	265	{
	266	int ret;
	267
	268	if (test_bit(WDT_IN_USE, &wdt_status)) {
df6707b2	269	orion5x_wdt_disable();
9e058d4f TR	270	clear_bit(WDT_IN_USE, &wdt_status);
	271	}
	272
	273	ret = misc_deregister(&orion5x_wdt_miscdev);
	274	if (!ret)
	275	orion5x_wdt_miscdev.parent = NULL;
22ac9232 SB	276
	277	return ret;
	278	}
	279
df6707b2 TR	280	static void orion5x_wdt_shutdown(struct platform_device *pdev)
	281	{
	282	if (test_bit(WDT_IN_USE, &wdt_status))
	283	orion5x_wdt_disable();
	284	}
	285
9e058d4f TR	286	static struct platform_driver orion5x_wdt_driver = {
	287	.probe = orion5x_wdt_probe,
	288	.remove = __devexit_p(orion5x_wdt_remove),
df6707b2	289	.shutdown = orion5x_wdt_shutdown,
9e058d4f TR	290	.driver = {
	291	.owner = THIS_MODULE,
	292	.name = "orion5x_wdt",
	293	},
	294	};
	295
	296	static int __init orion5x_wdt_init(void)
	297	{
	298	spin_lock_init(&wdt_lock);
	299	return platform_driver_register(&orion5x_wdt_driver);
	300	}
	301
22ac9232 SB	302	static void __exit orion5x_wdt_exit(void)
22ac9232 SB	303	{
9e058d4f	304	platform_driver_unregister(&orion5x_wdt_driver);
22ac9232 SB	305	}
	306
	307	module_init(orion5x_wdt_init);
	308	module_exit(orion5x_wdt_exit);
	309
	310	MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
	311	MODULE_DESCRIPTION("Orion5x Processor Watchdog");
	312
	313	module_param(heartbeat, int, 0);
df6707b2	314	MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
22ac9232 SB	315
22ac9232 SB	316	module_param(nowayout, int, 0);
df6707b2 TR	317	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
df6707b2 TR	318	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
22ac9232 SB	319
	320	MODULE_LICENSE("GPL");
	321	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);