[linux-2.6-block.git] / drivers / watchdog / mpc5200_wdt.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <asm/of_platform.h>
#include <asm/uaccess.h>
#include <asm/mpc52xx.h>


#define GPT_MODE_WDT		(1<<15)
#define GPT_MODE_CE		(1<<12)
#define GPT_MODE_MS_TIMER	(0x4)


struct mpc5200_wdt {
	unsigned count;	/* timer ticks before watchdog kicks in */
	long ipb_freq;
	struct miscdevice miscdev;
	struct resource mem;
	struct mpc52xx_gpt __iomem *regs;
	spinlock_t io_lock;
};

/* is_active stores wether or not the /dev/watchdog device is opened */
static unsigned long is_active;

/* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from
 * file operations, which sucks. But there can be max 1 watchdog anyway, so...
 */
static struct mpc5200_wdt *wdt_global;


/* helper to calculate timeout in timer counts */
static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout)
{
	/* use biggest prescaler of 64k */
	wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout;

	if (wdt->count > 0xffff)
		wdt->count = 0xffff;
}
/* return timeout in seconds (calculated from timer count) */
static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt)
{
	return wdt->count * 0x10000 / wdt->ipb_freq;
}


/* watchdog operations */
static int mpc5200_wdt_start(struct mpc5200_wdt *wdt)
{
	spin_lock(&wdt->io_lock);
	/* disable */
	out_be32(&wdt->regs->mode, 0);
	/* set timeout, with maximum prescaler */
	out_be32(&wdt->regs->count, 0x0 | wdt->count);
	/* enable watchdog */
	out_be32(&wdt->regs->mode, GPT_MODE_CE | GPT_MODE_WDT | GPT_MODE_MS_TIMER);
	spin_unlock(&wdt->io_lock);

	return 0;
}
static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt)
{
	spin_lock(&wdt->io_lock);
	/* writing A5 to OCPW resets the watchdog */
	out_be32(&wdt->regs->mode, 0xA5000000 | (0xffffff & in_be32(&wdt->regs->mode)));
	spin_unlock(&wdt->io_lock);
	return 0;
}
static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt)
{
	spin_lock(&wdt->io_lock);
	/* disable */
	out_be32(&wdt->regs->mode, 0);
	spin_unlock(&wdt->io_lock);
	return 0;
}


/* file operations */
static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data,
		size_t len, loff_t *ppos)
{
	struct mpc5200_wdt *wdt = file->private_data;
	mpc5200_wdt_ping(wdt);
	return 0;
}
static struct watchdog_info mpc5200_wdt_info = {
	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	.identity	= "mpc5200 watchdog on GPT0",
};
static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file,
		unsigned int cmd, unsigned long arg)
{
	struct mpc5200_wdt *wdt = file->private_data;
	int __user *data = (int __user *)arg;
	int timeout;
	int ret = 0;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = copy_to_user(data, &mpc5200_wdt_info,
			sizeof(mpc5200_wdt_info));
		if (ret)
			ret = -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		ret = put_user(0, data);
		break;

	case WDIOC_KEEPALIVE:
		mpc5200_wdt_ping(wdt);
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(timeout, data);
		if (ret)
			break;
		mpc5200_wdt_set_timeout(wdt, timeout);
		mpc5200_wdt_start(wdt);
		/* fall through and return the timeout */

	case WDIOC_GETTIMEOUT:
		timeout = mpc5200_wdt_get_timeout(wdt);
		ret = put_user(timeout, data);
		break;

	default:
		ret = -ENOTTY;
	}
	return ret;
}
static int mpc5200_wdt_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &is_active))
		return -EBUSY;

	/* Set and activate the watchdog */
	mpc5200_wdt_set_timeout(wdt_global, 30);
	mpc5200_wdt_start(wdt_global);
	file->private_data = wdt_global;
	return nonseekable_open(inode, file);
}
static int mpc5200_wdt_release(struct inode *inode, struct file *file)
{
#if WATCHDOG_NOWAYOUT == 0
	struct mpc5200_wdt *wdt = file->private_data;
	mpc5200_wdt_stop(wdt);
	wdt->count = 0;		/* == disabled */
#endif
	clear_bit(0, &is_active);
	return 0;
}

static const struct file_operations mpc5200_wdt_fops = {
	.owner	= THIS_MODULE,
	.write	= mpc5200_wdt_write,
	.ioctl	= mpc5200_wdt_ioctl,
	.open	= mpc5200_wdt_open,
	.release = mpc5200_wdt_release,
};

/* module operations */
static int mpc5200_wdt_probe(struct of_device *op, const struct of_device_id *match)
{
	struct mpc5200_wdt *wdt;
	int err;
	const void *has_wdt;
	int size;

	has_wdt = of_get_property(op->node, "has-wdt", NULL);
	if (!has_wdt)
		has_wdt = of_get_property(op->node, "fsl,has-wdt", NULL);
	if (!has_wdt)
		return -ENODEV;

	wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;

	wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node);

	err = of_address_to_resource(op->node, 0, &wdt->mem);
	if (err)
		goto out_free;
	size = wdt->mem.end - wdt->mem.start + 1;
	if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) {
		err = -ENODEV;
		goto out_free;
	}
	wdt->regs = ioremap(wdt->mem.start, size);
	if (!wdt->regs) {
		err = -ENODEV;
		goto out_release;
	}

	dev_set_drvdata(&op->dev, wdt);
	spin_lock_init(&wdt->io_lock);

	wdt->miscdev = (struct miscdevice) {
		.minor	= WATCHDOG_MINOR,
		.name	= "watchdog",
		.fops	= &mpc5200_wdt_fops,
		.parent = &op->dev,
	};
	wdt_global = wdt;
	err = misc_register(&wdt->miscdev);
	if (!err)
		return 0;

	iounmap(wdt->regs);
 out_release:
	release_mem_region(wdt->mem.start, size);
 out_free:
	kfree(wdt);
	return err;
}

static int mpc5200_wdt_remove(struct of_device *op)
{
	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);

	mpc5200_wdt_stop(wdt);
	misc_deregister(&wdt->miscdev);
	iounmap(wdt->regs);
	release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1);
	kfree(wdt);

	return 0;
}
static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state)
{
	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	mpc5200_wdt_stop(wdt);
	return 0;
}
static int mpc5200_wdt_resume(struct of_device *op)
{
	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	if (wdt->count)
		mpc5200_wdt_start(wdt);
	return 0;
}
static int mpc5200_wdt_shutdown(struct of_device *op)
{
	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	mpc5200_wdt_stop(wdt);
	return 0;
}

static struct of_device_id mpc5200_wdt_match[] = {
	{ .compatible = "mpc5200-gpt", },
	{ .compatible = "fsl,mpc5200-gpt", },
	{},
};
static struct of_platform_driver mpc5200_wdt_driver = {
	.owner		= THIS_MODULE,
	.name		= "mpc5200-gpt-wdt",
	.match_table	= mpc5200_wdt_match,
	.probe		= mpc5200_wdt_probe,
	.remove		= mpc5200_wdt_remove,
	.suspend	= mpc5200_wdt_suspend,
	.resume		= mpc5200_wdt_resume,
	.shutdown	= mpc5200_wdt_shutdown,
};


static int __init mpc5200_wdt_init(void)
{
	return of_register_platform_driver(&mpc5200_wdt_driver);
}

static void __exit mpc5200_wdt_exit(void)
{
	of_unregister_platform_driver(&mpc5200_wdt_driver);
}

module_init(mpc5200_wdt_init);
module_exit(mpc5200_wdt_exit);

MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
8cf18971 DP	1	#include <linux/init.h>
	2	#include <linux/module.h>
	3	#include <linux/miscdevice.h>
	4	#include <linux/watchdog.h>
	5	#include <linux/io.h>
de81225a	6	#include <linux/spinlock.h>
8cf18971 DP	7	#include <asm/of_platform.h>
	8	#include <asm/uaccess.h>
	9	#include <asm/mpc52xx.h>
	10
	11
	12	#define GPT_MODE_WDT (1<<15)
	13	#define GPT_MODE_CE (1<<12)
	14	#define GPT_MODE_MS_TIMER (0x4)
	15
	16
	17	struct mpc5200_wdt {
	18	unsigned count; /* timer ticks before watchdog kicks in */
	19	long ipb_freq;
	20	struct miscdevice miscdev;
	21	struct resource mem;
	22	struct mpc52xx_gpt __iomem *regs;
de81225a	23	spinlock_t io_lock;
8cf18971 DP	24	};
8cf18971 DP	25
de81225a WVS	26	/* is_active stores wether or not the /dev/watchdog device is opened */
de81225a WVS	27	static unsigned long is_active;
8cf18971 DP	28
	29	/* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from
	30	* file operations, which sucks. But there can be max 1 watchdog anyway, so...
	31	*/
	32	static struct mpc5200_wdt *wdt_global;
	33
	34
	35	/* helper to calculate timeout in timer counts */
	36	static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout)
	37	{
	38	/* use biggest prescaler of 64k */
	39	wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout;
	40
	41	if (wdt->count > 0xffff)
	42	wdt->count = 0xffff;
	43	}
	44	/* return timeout in seconds (calculated from timer count) */
	45	static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt)
	46	{
	47	return wdt->count * 0x10000 / wdt->ipb_freq;
	48	}
	49
	50
	51	/* watchdog operations */
	52	static int mpc5200_wdt_start(struct mpc5200_wdt *wdt)
	53	{
de81225a	54	spin_lock(&wdt->io_lock);
8cf18971 DP	55	/* disable */
	56	out_be32(&wdt->regs->mode, 0);
	57	/* set timeout, with maximum prescaler */
	58	out_be32(&wdt->regs->count, 0x0 \| wdt->count);
	59	/* enable watchdog */
	60	out_be32(&wdt->regs->mode, GPT_MODE_CE \| GPT_MODE_WDT \| GPT_MODE_MS_TIMER);
de81225a	61	spin_unlock(&wdt->io_lock);
8cf18971 DP	62
	63	return 0;
	64	}
	65	static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt)
	66	{
de81225a	67	spin_lock(&wdt->io_lock);
8cf18971 DP	68	/* writing A5 to OCPW resets the watchdog */
8cf18971 DP	69	out_be32(&wdt->regs->mode, 0xA5000000 \| (0xffffff & in_be32(&wdt->regs->mode)));
de81225a	70	spin_unlock(&wdt->io_lock);
8cf18971 DP	71	return 0;
	72	}
	73	static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt)
	74	{
de81225a WVS	75	spin_lock(&wdt->io_lock);
de81225a WVS	76	/* disable */
8cf18971	77	out_be32(&wdt->regs->mode, 0);
de81225a	78	spin_unlock(&wdt->io_lock);
8cf18971 DP	79	return 0;
	80	}
	81
	82
	83	/* file operations */
a39f9d02	84	static ssize_t mpc5200_wdt_write(struct file file, const char __user data,
8cf18971 DP	85	size_t len, loff_t *ppos)
	86	{
	87	struct mpc5200_wdt *wdt = file->private_data;
	88	mpc5200_wdt_ping(wdt);
	89	return 0;
	90	}
	91	static struct watchdog_info mpc5200_wdt_info = {
	92	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	93	.identity = "mpc5200 watchdog on GPT0",
	94	};
	95	static int mpc5200_wdt_ioctl(struct inode inode, struct file file,
	96	unsigned int cmd, unsigned long arg)
	97	{
	98	struct mpc5200_wdt *wdt = file->private_data;
	99	int __user data = (int __user )arg;
	100	int timeout;
	101	int ret = 0;
	102
	103	switch (cmd) {
	104	case WDIOC_GETSUPPORT:
de81225a WVS	105	ret = copy_to_user(data, &mpc5200_wdt_info,
de81225a WVS	106	sizeof(mpc5200_wdt_info));
8cf18971 DP	107	if (ret)
	108	ret = -EFAULT;
	109	break;
	110
de81225a WVS	111	case WDIOC_GETSTATUS:
	112	case WDIOC_GETBOOTSTATUS:
	113	ret = put_user(0, data);
	114	break;
	115
8cf18971 DP	116	case WDIOC_KEEPALIVE:
	117	mpc5200_wdt_ping(wdt);
	118	break;
	119
	120	case WDIOC_SETTIMEOUT:
	121	ret = get_user(timeout, data);
	122	if (ret)
	123	break;
	124	mpc5200_wdt_set_timeout(wdt, timeout);
	125	mpc5200_wdt_start(wdt);
	126	/* fall through and return the timeout */
	127
	128	case WDIOC_GETTIMEOUT:
	129	timeout = mpc5200_wdt_get_timeout(wdt);
	130	ret = put_user(timeout, data);
	131	break;
de81225a WVS	132
	133	default:
	134	ret = -ENOTTY;
8cf18971 DP	135	}
	136	return ret;
	137	}
	138	static int mpc5200_wdt_open(struct inode inode, struct file file)
	139	{
de81225a WVS	140	/* /dev/watchdog can only be opened once */
	141	if (test_and_set_bit(0, &is_active))
	142	return -EBUSY;
	143
	144	/* Set and activate the watchdog */
8cf18971 DP	145	mpc5200_wdt_set_timeout(wdt_global, 30);
	146	mpc5200_wdt_start(wdt_global);
	147	file->private_data = wdt_global;
de81225a	148	return nonseekable_open(inode, file);
8cf18971 DP	149	}
	150	static int mpc5200_wdt_release(struct inode inode, struct file file)
	151	{
	152	#if WATCHDOG_NOWAYOUT == 0
	153	struct mpc5200_wdt *wdt = file->private_data;
	154	mpc5200_wdt_stop(wdt);
	155	wdt->count = 0; /* == disabled */
	156	#endif
de81225a	157	clear_bit(0, &is_active);
8cf18971 DP	158	return 0;
	159	}
	160
b47a166e	161	static const struct file_operations mpc5200_wdt_fops = {
8cf18971 DP	162	.owner = THIS_MODULE,
	163	.write = mpc5200_wdt_write,
	164	.ioctl = mpc5200_wdt_ioctl,
	165	.open = mpc5200_wdt_open,
	166	.release = mpc5200_wdt_release,
	167	};
	168
	169	/* module operations */
	170	static int mpc5200_wdt_probe(struct of_device op, const struct of_device_id match)
	171	{
	172	struct mpc5200_wdt *wdt;
	173	int err;
	174	const void *has_wdt;
	175	int size;
	176
	177	has_wdt = of_get_property(op->node, "has-wdt", NULL);
d24bc314 MB	178	if (!has_wdt)
d24bc314 MB	179	has_wdt = of_get_property(op->node, "fsl,has-wdt", NULL);
8cf18971 DP	180	if (!has_wdt)
	181	return -ENODEV;
	182
	183	wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
	184	if (!wdt)
	185	return -ENOMEM;
	186
	187	wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node);
	188
	189	err = of_address_to_resource(op->node, 0, &wdt->mem);
	190	if (err)
	191	goto out_free;
	192	size = wdt->mem.end - wdt->mem.start + 1;
	193	if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) {
	194	err = -ENODEV;
	195	goto out_free;
	196	}
	197	wdt->regs = ioremap(wdt->mem.start, size);
	198	if (!wdt->regs) {
	199	err = -ENODEV;
	200	goto out_release;
	201	}
	202
	203	dev_set_drvdata(&op->dev, wdt);
de81225a	204	spin_lock_init(&wdt->io_lock);
8cf18971 DP	205
	206	wdt->miscdev = (struct miscdevice) {
	207	.minor = WATCHDOG_MINOR,
	208	.name = "watchdog",
	209	.fops = &mpc5200_wdt_fops,
	210	.parent = &op->dev,
	211	};
	212	wdt_global = wdt;
	213	err = misc_register(&wdt->miscdev);
	214	if (!err)
	215	return 0;
	216
	217	iounmap(wdt->regs);
	218	out_release:
	219	release_mem_region(wdt->mem.start, size);
	220	out_free:
	221	kfree(wdt);
	222	return err;
	223	}
	224
	225	static int mpc5200_wdt_remove(struct of_device *op)
	226	{
	227	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	228
	229	mpc5200_wdt_stop(wdt);
	230	misc_deregister(&wdt->miscdev);
	231	iounmap(wdt->regs);
	232	release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1);
	233	kfree(wdt);
	234
	235	return 0;
	236	}
	237	static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state)
	238	{
	239	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	240	mpc5200_wdt_stop(wdt);
	241	return 0;
	242	}
	243	static int mpc5200_wdt_resume(struct of_device *op)
	244	{
	245	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	246	if (wdt->count)
	247	mpc5200_wdt_start(wdt);
	248	return 0;
	249	}
	250	static int mpc5200_wdt_shutdown(struct of_device *op)
	251	{
	252	struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
	253	mpc5200_wdt_stop(wdt);
	254	return 0;
	255	}
	256
	257	static struct of_device_id mpc5200_wdt_match[] = {
	258	{ .compatible = "mpc5200-gpt", },
d24bc314	259	{ .compatible = "fsl,mpc5200-gpt", },
8cf18971 DP	260	{},
	261	};
	262	static struct of_platform_driver mpc5200_wdt_driver = {
	263	.owner = THIS_MODULE,
	264	.name = "mpc5200-gpt-wdt",
	265	.match_table = mpc5200_wdt_match,
	266	.probe = mpc5200_wdt_probe,
	267	.remove = mpc5200_wdt_remove,
	268	.suspend = mpc5200_wdt_suspend,
	269	.resume = mpc5200_wdt_resume,
	270	.shutdown = mpc5200_wdt_shutdown,
	271	};
	272
	273
	274	static int __init mpc5200_wdt_init(void)
	275	{
	276	return of_register_platform_driver(&mpc5200_wdt_driver);
	277	}
	278
	279	static void __exit mpc5200_wdt_exit(void)
	280	{
	281	of_unregister_platform_driver(&mpc5200_wdt_driver);
	282	}
	283
	284	module_init(mpc5200_wdt_init);
	285	module_exit(mpc5200_wdt_exit);
	286
	287	MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>");
	288	MODULE_LICENSE("Dual BSD/GPL");
de81225a	289	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);