[deliverable/linux.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 <mach/bridge-regs.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>
fdd8b079	25	#include <mach/bridge-regs.h>
9e058d4f	26	#include <plat/orion5x_wdt.h>
22ac9232 SB	27
	28	/*
	29	* Watchdog timer block registers.
	30	*/
	31	#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
	32	#define WDT_EN 0x0010
	33	#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
	34
9e058d4f	35	#define WDT_MAX_CYCLE_COUNT 0xffffffff
22ac9232 SB	36	#define WDT_IN_USE 0
	37	#define WDT_OK_TO_CLOSE 1
	38
	39	static int nowayout = WATCHDOG_NOWAYOUT;
9e058d4f TR	40	static int heartbeat = -1; /* module parameter (seconds) */
	41	static unsigned int wdt_max_duration; /* (seconds) */
	42	static unsigned int wdt_tclk;
22ac9232	43	static unsigned long wdt_status;
6d0f0dfd	44	static spinlock_t wdt_lock;
22ac9232	45
df6707b2 TR	46	static void orion5x_wdt_ping(void)
	47	{
	48	spin_lock(&wdt_lock);
	49
	50	/* Reload watchdog duration */
	51	writel(wdt_tclk * heartbeat, WDT_VAL);
	52
	53	spin_unlock(&wdt_lock);
	54	}
	55
	56	static void orion5x_wdt_enable(void)
22ac9232 SB	57	{
	58	u32 reg;
	59
6d0f0dfd WVS	60	spin_lock(&wdt_lock);
6d0f0dfd WVS	61
22ac9232	62	/* Set watchdog duration */
9e058d4f	63	writel(wdt_tclk * heartbeat, WDT_VAL);
22ac9232 SB	64
	65	/* Clear watchdog timer interrupt */
	66	reg = readl(BRIDGE_CAUSE);
	67	reg &= ~WDT_INT_REQ;
	68	writel(reg, BRIDGE_CAUSE);
	69
	70	/* Enable watchdog timer */
	71	reg = readl(TIMER_CTRL);
	72	reg \|= WDT_EN;
	73	writel(reg, TIMER_CTRL);
	74
	75	/* Enable reset on watchdog */
	76	reg = readl(CPU_RESET_MASK);
	77	reg \|= WDT_RESET;
	78	writel(reg, CPU_RESET_MASK);
6d0f0dfd WVS	79
6d0f0dfd WVS	80	spin_unlock(&wdt_lock);
22ac9232 SB	81	}
22ac9232 SB	82
df6707b2	83	static void orion5x_wdt_disable(void)
22ac9232 SB	84	{
	85	u32 reg;
	86
6d0f0dfd WVS	87	spin_lock(&wdt_lock);
6d0f0dfd WVS	88
22ac9232 SB	89	/* Disable reset on watchdog */
	90	reg = readl(CPU_RESET_MASK);
	91	reg &= ~WDT_RESET;
	92	writel(reg, CPU_RESET_MASK);
	93
	94	/* Disable watchdog timer */
	95	reg = readl(TIMER_CTRL);
	96	reg &= ~WDT_EN;
	97	writel(reg, TIMER_CTRL);
6d0f0dfd WVS	98
	99	spin_unlock(&wdt_lock);
	100	}
	101
	102	static int orion5x_wdt_get_timeleft(int *time_left)
	103	{
	104	spin_lock(&wdt_lock);
9e058d4f	105	*time_left = readl(WDT_VAL) / wdt_tclk;
6d0f0dfd WVS	106	spin_unlock(&wdt_lock);
6d0f0dfd WVS	107	return 0;
22ac9232 SB	108	}
	109
	110	static int orion5x_wdt_open(struct inode inode, struct file file)
	111	{
	112	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
	113	return -EBUSY;
	114	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
df6707b2	115	orion5x_wdt_enable();
22ac9232 SB	116	return nonseekable_open(inode, file);
	117	}
	118
22ac9232 SB	119	static ssize_t orion5x_wdt_write(struct file file, const char data,
	120	size_t len, loff_t *ppos)
	121	{
	122	if (len) {
	123	if (!nowayout) {
	124	size_t i;
	125
	126	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	127	for (i = 0; i != len; i++) {
	128	char c;
	129
	130	if (get_user(c, data + i))
	131	return -EFAULT;
	132	if (c == 'V')
	133	set_bit(WDT_OK_TO_CLOSE, &wdt_status);
	134	}
	135	}
df6707b2	136	orion5x_wdt_ping();
22ac9232 SB	137	}
	138	return len;
	139	}
	140
df6707b2 TR	141	static int orion5x_wdt_settimeout(int new_time)
	142	{
	143	if ((new_time <= 0) \|\| (new_time > wdt_max_duration))
	144	return -EINVAL;
	145
	146	/* Set new watchdog time to be used when
	147	* orion5x_wdt_enable() or orion5x_wdt_ping() is called. */
	148	heartbeat = new_time;
	149	return 0;
	150	}
	151
	152	static const struct watchdog_info ident = {
22ac9232 SB	153	.options = WDIOF_MAGICCLOSE \| WDIOF_SETTIMEOUT \|
	154	WDIOF_KEEPALIVEPING,
	155	.identity = "Orion5x Watchdog",
	156	};
	157
22ac9232 SB	158	static long orion5x_wdt_ioctl(struct file *file, unsigned int cmd,
	159	unsigned long arg)
	160	{
	161	int ret = -ENOTTY;
	162	int time;
	163
	164	switch (cmd) {
	165	case WDIOC_GETSUPPORT:
	166	ret = copy_to_user((struct watchdog_info *)arg, &ident,
	167	sizeof(ident)) ? -EFAULT : 0;
	168	break;
	169
	170	case WDIOC_GETSTATUS:
	171	case WDIOC_GETBOOTSTATUS:
	172	ret = put_user(0, (int *)arg);
	173	break;
	174
	175	case WDIOC_KEEPALIVE:
df6707b2	176	orion5x_wdt_ping();
22ac9232 SB	177	ret = 0;
	178	break;
	179
	180	case WDIOC_SETTIMEOUT:
	181	ret = get_user(time, (int *)arg);
	182	if (ret)
	183	break;
	184
df6707b2	185	if (orion5x_wdt_settimeout(time)) {
22ac9232 SB	186	ret = -EINVAL;
	187	break;
	188	}
df6707b2	189	orion5x_wdt_ping();
22ac9232 SB	190	/* Fall through */
	191
	192	case WDIOC_GETTIMEOUT:
	193	ret = put_user(heartbeat, (int *)arg);
	194	break;
	195
	196	case WDIOC_GETTIMELEFT:
	197	if (orion5x_wdt_get_timeleft(&time)) {
	198	ret = -EINVAL;
	199	break;
	200	}
	201	ret = put_user(time, (int *)arg);
	202	break;
	203	}
	204	return ret;
	205	}
	206
	207	static int orion5x_wdt_release(struct inode inode, struct file file)
	208	{
	209	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
df6707b2	210	orion5x_wdt_disable();
22ac9232 SB	211	else
	212	printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
	213	"timer will not stop\n");
	214	clear_bit(WDT_IN_USE, &wdt_status);
	215	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	216
	217	return 0;
	218	}
	219
	220
	221	static const struct file_operations orion5x_wdt_fops = {
	222	.owner = THIS_MODULE,
	223	.llseek = no_llseek,
	224	.write = orion5x_wdt_write,
	225	.unlocked_ioctl = orion5x_wdt_ioctl,
	226	.open = orion5x_wdt_open,
	227	.release = orion5x_wdt_release,
	228	};
	229
	230	static struct miscdevice orion5x_wdt_miscdev = {
	231	.minor = WATCHDOG_MINOR,
	232	.name = "watchdog",
	233	.fops = &orion5x_wdt_fops,
	234	};
	235
9e058d4f	236	static int __devinit orion5x_wdt_probe(struct platform_device *pdev)
22ac9232	237	{
9e058d4f	238	struct orion5x_wdt_platform_data *pdata = pdev->dev.platform_data;
22ac9232 SB	239	int ret;
22ac9232 SB	240
9e058d4f TR	241	if (pdata) {
	242	wdt_tclk = pdata->tclk;
	243	} else {
	244	printk(KERN_ERR "Orion5x Watchdog misses platform data\n");
	245	return -ENODEV;
	246	}
	247
	248	if (orion5x_wdt_miscdev.parent)
	249	return -EBUSY;
	250	orion5x_wdt_miscdev.parent = &pdev->dev;
	251
	252	wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
df6707b2	253	if (orion5x_wdt_settimeout(heartbeat))
9e058d4f	254	heartbeat = wdt_max_duration;
6d0f0dfd	255
22ac9232	256	ret = misc_register(&orion5x_wdt_miscdev);
9e058d4f TR	257	if (ret)
	258	return ret;
	259
	260	printk(KERN_INFO "Orion5x Watchdog Timer: Initial timeout %d sec%s\n",
	261	heartbeat, nowayout ? ", nowayout" : "");
	262	return 0;
	263	}
	264
	265	static int __devexit orion5x_wdt_remove(struct platform_device *pdev)
	266	{
	267	int ret;
	268
	269	if (test_bit(WDT_IN_USE, &wdt_status)) {
df6707b2	270	orion5x_wdt_disable();
9e058d4f TR	271	clear_bit(WDT_IN_USE, &wdt_status);
	272	}
	273
	274	ret = misc_deregister(&orion5x_wdt_miscdev);
	275	if (!ret)
	276	orion5x_wdt_miscdev.parent = NULL;
22ac9232 SB	277
	278	return ret;
	279	}
	280
df6707b2 TR	281	static void orion5x_wdt_shutdown(struct platform_device *pdev)
	282	{
	283	if (test_bit(WDT_IN_USE, &wdt_status))
	284	orion5x_wdt_disable();
	285	}
	286
9e058d4f TR	287	static struct platform_driver orion5x_wdt_driver = {
	288	.probe = orion5x_wdt_probe,
	289	.remove = __devexit_p(orion5x_wdt_remove),
df6707b2	290	.shutdown = orion5x_wdt_shutdown,
9e058d4f TR	291	.driver = {
	292	.owner = THIS_MODULE,
	293	.name = "orion5x_wdt",
	294	},
	295	};
	296
	297	static int __init orion5x_wdt_init(void)
	298	{
	299	spin_lock_init(&wdt_lock);
	300	return platform_driver_register(&orion5x_wdt_driver);
	301	}
	302
22ac9232 SB	303	static void __exit orion5x_wdt_exit(void)
22ac9232 SB	304	{
9e058d4f	305	platform_driver_unregister(&orion5x_wdt_driver);
22ac9232 SB	306	}
	307
	308	module_init(orion5x_wdt_init);
	309	module_exit(orion5x_wdt_exit);
	310
	311	MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
	312	MODULE_DESCRIPTION("Orion5x Processor Watchdog");
	313
	314	module_param(heartbeat, int, 0);
df6707b2	315	MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
22ac9232 SB	316
22ac9232 SB	317	module_param(nowayout, int, 0);
df6707b2 TR	318	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
df6707b2 TR	319	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
22ac9232 SB	320
	321	MODULE_LICENSE("GPL");
	322	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);