[mirror_ubuntu-zesty-kernel.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@redhat.com>
 *
 *	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>

#ifdef CONFIG_ARCH_PXA
#include <asm/arch/pxa-regs.h>
#endif

#include <asm/hardware.h>

#define OSCR_FREQ		CLOCK_TICK_RATE

static unsigned long sa1100wdt_users;
static 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",
};

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 || time > 255) {
			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;

	/*
	 * 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 = (RCSR & RCSR_WDR) ? 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	*
	4	* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
	5	* Based on SoftDog driver by Alan Cox <alan@redhat.com>
	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	*
	18	* 27/11/2000 Initial release
	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>
1da177e4 LT	30
	31	#ifdef CONFIG_ARCH_PXA
	32	#include <asm/arch/pxa-regs.h>
	33	#endif
	34
	35	#include <asm/hardware.h>
1da177e4 LT	36
1da177e4 LT	37	#define OSCR_FREQ CLOCK_TICK_RATE
1da177e4 LT	38
1da177e4 LT	39	static unsigned long sa1100wdt_users;
1da177e4 LT	40	static int pre_margin;
1da177e4 LT	41	static int boot_status;
1da177e4 LT	42
	43	/*
	44	* Allow only one person to hold it open
	45	*/
	46	static int sa1100dog_open(struct inode inode, struct file file)
	47	{
f19e0312	48	if (test_and_set_bit(1, &sa1100wdt_users))
1da177e4 LT	49	return -EBUSY;
	50
	51	/* Activate SA1100 Watchdog timer */
	52	OSMR3 = OSCR + pre_margin;
	53	OSSR = OSSR_M3;
	54	OWER = OWER_WME;
	55	OIER \|= OIER_E3;
6abe78bf	56	return nonseekable_open(inode, file);
1da177e4 LT	57	}
	58
	59	/*
9bbd0375 IC	60	* The watchdog cannot be disabled.
	61	*
	62	* Previous comments suggested that turning off the interrupt by
	63	* clearing OIER[E3] would prevent the watchdog timing out but this
	64	* does not appear to be true (at least on the PXA255).
1da177e4 LT	65	*/
	66	static int sa1100dog_release(struct inode inode, struct file file)
	67	{
9bbd0375	68	printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
1da177e4	69	clear_bit(1, &sa1100wdt_users);
1da177e4 LT	70	return 0;
	71	}
	72
f19e0312 AC	73	static ssize_t sa1100dog_write(struct file file, const char __user data,
f19e0312 AC	74	size_t len, loff_t *ppos)
1da177e4	75	{
9bbd0375	76	if (len)
1da177e4 LT	77	/* Refresh OSMR3 timer. */
1da177e4 LT	78	OSMR3 = OSCR + pre_margin;
1da177e4 LT	79	return len;
	80	}
	81
f19e0312 AC	82	static const struct watchdog_info ident = {
	83	.options = WDIOF_CARDRESET \| WDIOF_SETTIMEOUT
	84	\| WDIOF_KEEPALIVEPING,
9bbd0375	85	.identity = "SA1100/PXA255 Watchdog",
1da177e4 LT	86	};
1da177e4 LT	87
f19e0312 AC	88	static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
f19e0312 AC	89	unsigned long arg)
1da177e4	90	{
795b89d2	91	int ret = -ENOTTY;
1da177e4	92	int time;
3a69e579 IC	93	void __user argp = (void __user )arg;
3a69e579 IC	94	int __user *p = argp;
1da177e4 LT	95
	96	switch (cmd) {
	97	case WDIOC_GETSUPPORT:
3a69e579	98	ret = copy_to_user(argp, &ident,
1da177e4 LT	99	sizeof(ident)) ? -EFAULT : 0;
	100	break;
	101
	102	case WDIOC_GETSTATUS:
3a69e579	103	ret = put_user(0, p);
1da177e4 LT	104	break;
	105
	106	case WDIOC_GETBOOTSTATUS:
3a69e579	107	ret = put_user(boot_status, p);
1da177e4 LT	108	break;
1da177e4 LT	109
0c06090c WVS	110	case WDIOC_KEEPALIVE:
	111	OSMR3 = OSCR + pre_margin;
	112	ret = 0;
	113	break;
	114
1da177e4	115	case WDIOC_SETTIMEOUT:
3a69e579	116	ret = get_user(time, p);
1da177e4 LT	117	if (ret)
	118	break;
	119
	120	if (time <= 0 \|\| time > 255) {
	121	ret = -EINVAL;
	122	break;
	123	}
	124
	125	pre_margin = OSCR_FREQ * time;
	126	OSMR3 = OSCR + pre_margin;
	127	/fall through/
	128
	129	case WDIOC_GETTIMEOUT:
3a69e579	130	ret = put_user(pre_margin / OSCR_FREQ, p);
1da177e4	131	break;
1da177e4 LT	132	}
	133	return ret;
	134	}
	135
f19e0312	136	static const struct file_operations sa1100dog_fops = {
1da177e4 LT	137	.owner = THIS_MODULE,
	138	.llseek = no_llseek,
	139	.write = sa1100dog_write,
f19e0312	140	.unlocked_ioctl = sa1100dog_ioctl,
1da177e4 LT	141	.open = sa1100dog_open,
	142	.release = sa1100dog_release,
	143	};
	144
f19e0312	145	static struct miscdevice sa1100dog_miscdev = {
1da177e4	146	.minor = WATCHDOG_MINOR,
9bbd0375	147	.name = "watchdog",
1da177e4 LT	148	.fops = &sa1100dog_fops,
	149	};
	150
	151	static int margin __initdata = 60; /* (secs) Default is 1 minute */
	152
	153	static int __init sa1100dog_init(void)
	154	{
	155	int ret;
	156
	157	/*
	158	* Read the reset status, and save it for later. If
	159	* we suspend, RCSR will be cleared, and the watchdog
	160	* reset reason will be lost.
	161	*/
	162	boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;
	163	pre_margin = OSCR_FREQ * margin;
	164
	165	ret = misc_register(&sa1100dog_miscdev);
	166	if (ret == 0)
f19e0312 AC	167	printk(KERN_INFO
	168	"SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
	169	margin);
1da177e4 LT	170	return ret;
	171	}
	172
	173	static void __exit sa1100dog_exit(void)
	174	{
	175	misc_deregister(&sa1100dog_miscdev);
	176	}
	177
	178	module_init(sa1100dog_init);
	179	module_exit(sa1100dog_exit);
	180
	181	MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
	182	MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
	183
	184	module_param(margin, int, 0);
	185	MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
	186
1da177e4 LT	187	MODULE_LICENSE("GPL");
1da177e4 LT	188	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);