[net-next-2.6.git] / drivers / watchdog / sa1100_wdt.c

/*
 *	Watchdog driver for the SA11x0/PXA2xx
 *
 *	(c) Copyright 2000 Oleg Drokin <green@crimea.edu>
 *	    Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 *	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.
 *
 *	Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 2000           Oleg Drokin <green@crimea.edu>
 *
 *	27/11/2000 Initial release
 */
#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/watchdog.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/uaccess.h>
#include <linux/timex.h>

#ifdef CONFIG_ARCH_PXA
#include <mach/regs-ost.h>
#endif

#include <mach/reset.h>
#include <mach/hardware.h>

static unsigned long oscr_freq;
static unsigned long sa1100wdt_users;
static unsigned int pre_margin;
static int boot_status;

/*
 *	Allow only one person to hold it open
 */
static int sa1100dog_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(1, &sa1100wdt_users))
		return -EBUSY;

	/* Activate SA1100 Watchdog timer */
	OSMR3 = OSCR + pre_margin;
	OSSR = OSSR_M3;
	OWER = OWER_WME;
	OIER |= OIER_E3;
	return nonseekable_open(inode, file);
}

/*
 * The watchdog cannot be disabled.
 *
 * Previous comments suggested that turning off the interrupt by
 * clearing OIER[E3] would prevent the watchdog timing out but this
 * does not appear to be true (at least on the PXA255).
 */
static int sa1100dog_release(struct inode *inode, struct file *file)
{
	printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
	clear_bit(1, &sa1100wdt_users);
	return 0;
}

static ssize_t sa1100dog_write(struct file *file, const char __user *data,
						size_t len, loff_t *ppos)
{
	if (len)
		/* Refresh OSMR3 timer. */
		OSMR3 = OSCR + pre_margin;
	return len;
}

static const struct watchdog_info ident = {
	.options	= WDIOF_CARDRESET | WDIOF_SETTIMEOUT
				| WDIOF_KEEPALIVEPING,
	.identity	= "SA1100/PXA255 Watchdog",
	.firmware_version	= 1,
};

static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int ret = -ENOTTY;
	int time;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;

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

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

	case WDIOC_GETBOOTSTATUS:
		ret = put_user(boot_status, p);
		break;

	case WDIOC_KEEPALIVE:
		OSMR3 = OSCR + pre_margin;
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(time, p);
		if (ret)
			break;

		if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
			ret = -EINVAL;
			break;
		}

		pre_margin = oscr_freq * time;
		OSMR3 = OSCR + pre_margin;
		/*fall through*/

	case WDIOC_GETTIMEOUT:
		ret = put_user(pre_margin / oscr_freq, p);
		break;
	}
	return ret;
}

static const struct file_operations sa1100dog_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= sa1100dog_write,
	.unlocked_ioctl	= sa1100dog_ioctl,
	.open		= sa1100dog_open,
	.release	= sa1100dog_release,
};

static struct miscdevice sa1100dog_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &sa1100dog_fops,
};

static int margin __initdata = 60;		/* (secs) Default is 1 minute */

static int __init sa1100dog_init(void)
{
	int ret;

	oscr_freq = get_clock_tick_rate();

	/*
	 * Read the reset status, and save it for later.  If
	 * we suspend, RCSR will be cleared, and the watchdog
	 * reset reason will be lost.
	 */
	boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
				WDIOF_CARDRESET : 0;
	pre_margin = oscr_freq * margin;

	ret = misc_register(&sa1100dog_miscdev);
	if (ret == 0)
		printk(KERN_INFO
			"SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
						margin);
	return ret;
}

static void __exit sa1100dog_exit(void)
{
	misc_deregister(&sa1100dog_miscdev);
}

module_init(sa1100dog_init);
module_exit(sa1100dog_exit);

MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");

module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Watchdog driver for the SA11x0/PXA2xx
	3	*
143a2e54 WVS	4	* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
143a2e54 WVS	5	* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 LT	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	* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
	13	* warranty for any of this software. This material is provided
	14	* "AS-IS" and at no charge.
	15	*
	16	* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
	17	*
143a2e54	18	* 27/11/2000 Initial release
1da177e4	19	*/
1da177e4 LT	20	#include <linux/module.h>
	21	#include <linux/moduleparam.h>
	22	#include <linux/types.h>
	23	#include <linux/kernel.h>
	24	#include <linux/fs.h>
	25	#include <linux/miscdevice.h>
	26	#include <linux/watchdog.h>
	27	#include <linux/init.h>
1977f032	28	#include <linux/bitops.h>
f19e0312	29	#include <linux/uaccess.h>
87c52578	30	#include <linux/timex.h>
1da177e4 LT	31
1da177e4 LT	32	#ifdef CONFIG_ARCH_PXA
5bf3df3f	33	#include <mach/regs-ost.h>
1da177e4 LT	34	#endif
1da177e4 LT	35
afd2fc02	36	#include <mach/reset.h>
a09e64fb	37	#include <mach/hardware.h>
1da177e4	38
28a62385	39	static unsigned long oscr_freq;
1da177e4	40	static unsigned long sa1100wdt_users;
a6f052e3	41	static unsigned int pre_margin;
1da177e4	42	static int boot_status;
1da177e4 LT	43
	44	/*
	45	* Allow only one person to hold it open
	46	*/
	47	static int sa1100dog_open(struct inode inode, struct file file)
	48	{
f19e0312	49	if (test_and_set_bit(1, &sa1100wdt_users))
1da177e4 LT	50	return -EBUSY;
	51
	52	/* Activate SA1100 Watchdog timer */
	53	OSMR3 = OSCR + pre_margin;
	54	OSSR = OSSR_M3;
	55	OWER = OWER_WME;
	56	OIER \|= OIER_E3;
6abe78bf	57	return nonseekable_open(inode, file);
1da177e4 LT	58	}
	59
	60	/*
9bbd0375 IC	61	* The watchdog cannot be disabled.
	62	*
	63	* Previous comments suggested that turning off the interrupt by
	64	* clearing OIER[E3] would prevent the watchdog timing out but this
	65	* does not appear to be true (at least on the PXA255).
1da177e4 LT	66	*/
	67	static int sa1100dog_release(struct inode inode, struct file file)
	68	{
9bbd0375	69	printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
1da177e4	70	clear_bit(1, &sa1100wdt_users);
1da177e4 LT	71	return 0;
	72	}
	73
f19e0312 AC	74	static ssize_t sa1100dog_write(struct file file, const char __user data,
f19e0312 AC	75	size_t len, loff_t *ppos)
1da177e4	76	{
9bbd0375	77	if (len)
1da177e4 LT	78	/* Refresh OSMR3 timer. */
1da177e4 LT	79	OSMR3 = OSCR + pre_margin;
1da177e4 LT	80	return len;
	81	}
	82
f19e0312 AC	83	static const struct watchdog_info ident = {
	84	.options = WDIOF_CARDRESET \| WDIOF_SETTIMEOUT
	85	\| WDIOF_KEEPALIVEPING,
9bbd0375	86	.identity = "SA1100/PXA255 Watchdog",
a6f052e3	87	.firmware_version = 1,
1da177e4 LT	88	};
1da177e4 LT	89
f19e0312 AC	90	static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
f19e0312 AC	91	unsigned long arg)
1da177e4	92	{
795b89d2	93	int ret = -ENOTTY;
1da177e4	94	int time;
3a69e579 IC	95	void __user argp = (void __user )arg;
3a69e579 IC	96	int __user *p = argp;
1da177e4 LT	97
	98	switch (cmd) {
	99	case WDIOC_GETSUPPORT:
3a69e579	100	ret = copy_to_user(argp, &ident,
1da177e4 LT	101	sizeof(ident)) ? -EFAULT : 0;
	102	break;
	103
	104	case WDIOC_GETSTATUS:
3a69e579	105	ret = put_user(0, p);
1da177e4 LT	106	break;
	107
	108	case WDIOC_GETBOOTSTATUS:
3a69e579	109	ret = put_user(boot_status, p);
1da177e4 LT	110	break;
1da177e4 LT	111
0c06090c WVS	112	case WDIOC_KEEPALIVE:
	113	OSMR3 = OSCR + pre_margin;
	114	ret = 0;
	115	break;
	116
1da177e4	117	case WDIOC_SETTIMEOUT:
3a69e579	118	ret = get_user(time, p);
1da177e4 LT	119	if (ret)
	120	break;
	121
a6f052e3	122	if (time <= 0 \|\| (oscr_freq * (long long)time >= 0xffffffff)) {
1da177e4 LT	123	ret = -EINVAL;
	124	break;
	125	}
	126
28a62385	127	pre_margin = oscr_freq * time;
1da177e4 LT	128	OSMR3 = OSCR + pre_margin;
	129	/fall through/
	130
	131	case WDIOC_GETTIMEOUT:
28a62385	132	ret = put_user(pre_margin / oscr_freq, p);
1da177e4	133	break;
1da177e4 LT	134	}
	135	return ret;
	136	}
	137
f19e0312	138	static const struct file_operations sa1100dog_fops = {
1da177e4 LT	139	.owner = THIS_MODULE,
	140	.llseek = no_llseek,
	141	.write = sa1100dog_write,
f19e0312	142	.unlocked_ioctl = sa1100dog_ioctl,
1da177e4 LT	143	.open = sa1100dog_open,
	144	.release = sa1100dog_release,
	145	};
	146
f19e0312	147	static struct miscdevice sa1100dog_miscdev = {
1da177e4	148	.minor = WATCHDOG_MINOR,
9bbd0375	149	.name = "watchdog",
1da177e4 LT	150	.fops = &sa1100dog_fops,
	151	};
	152
	153	static int margin __initdata = 60; /* (secs) Default is 1 minute */
	154
	155	static int __init sa1100dog_init(void)
	156	{
	157	int ret;
	158
28a62385 EM	159	oscr_freq = get_clock_tick_rate();
28a62385 EM	160
1da177e4 LT	161	/*
	162	* Read the reset status, and save it for later. If
	163	* we suspend, RCSR will be cleared, and the watchdog
	164	* reset reason will be lost.
	165	*/
214c6a7e EM	166	boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
214c6a7e EM	167	WDIOF_CARDRESET : 0;
28a62385	168	pre_margin = oscr_freq * margin;
1da177e4 LT	169
	170	ret = misc_register(&sa1100dog_miscdev);
	171	if (ret == 0)
f19e0312 AC	172	printk(KERN_INFO
	173	"SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
	174	margin);
1da177e4 LT	175	return ret;
	176	}
	177
	178	static void __exit sa1100dog_exit(void)
	179	{
	180	misc_deregister(&sa1100dog_miscdev);
	181	}
	182
	183	module_init(sa1100dog_init);
	184	module_exit(sa1100dog_exit);
	185
	186	MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
	187	MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
	188
	189	module_param(margin, int, 0);
	190	MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
	191
1da177e4 LT	192	MODULE_LICENSE("GPL");
1da177e4 LT	193	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);