[mirror_ubuntu-artful-kernel.git] / drivers / watchdog / mpc8xx_wdt.c

/*
 * mpc8xx_wdt.c - MPC8xx watchdog userspace interface
 *
 * Author: Florian Schirmer <jolt@tuxbox.org>
 *
 * 2002 (c) Florian Schirmer <jolt@tuxbox.org> 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/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <asm/8xx_immap.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <syslib/m8xx_wdt.h>

static unsigned long wdt_opened;
static int wdt_status;
static spinlock_t wdt_lock;

static void mpc8xx_wdt_handler_disable(void)
{
	volatile uint __iomem *piscr;
	piscr = (uint *)&((immap_t *)IMAP_ADDR)->im_sit.sit_piscr;

	if (!m8xx_has_internal_rtc)
		m8xx_wdt_stop_timer();
	else
		out_be32(piscr, in_be32(piscr) & ~(PISCR_PIE | PISCR_PTE));
	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
}

static void mpc8xx_wdt_handler_enable(void)
{
	volatile uint __iomem *piscr;
	piscr = (uint *)&((immap_t *)IMAP_ADDR)->im_sit.sit_piscr;

	if (!m8xx_has_internal_rtc)
		m8xx_wdt_install_timer();
	else
		out_be32(piscr, in_be32(piscr) | PISCR_PIE | PISCR_PTE);
	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
}

static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &wdt_opened))
		return -EBUSY;
	m8xx_wdt_reset();
	mpc8xx_wdt_handler_disable();
	return nonseekable_open(inode, file);
}

static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
{
	m8xx_wdt_reset();
#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
	mpc8xx_wdt_handler_enable();
#endif
	clear_bit(0, &wdt_opened);
	return 0;
}

static ssize_t mpc8xx_wdt_write(struct file *file, const char *data,
						size_t len, loff_t *ppos)
{
	if (len) {
		spin_lock(&wdt_lock);
		m8xx_wdt_reset();
		spin_unlock(&wdt_lock);
	}
	return len;
}

static long mpc8xx_wdt_ioctl(struct file *file,
					unsigned int cmd, unsigned long arg)
{
	int timeout;
	static struct watchdog_info info = {
		.options = WDIOF_KEEPALIVEPING,
		.firmware_version = 0,
		.identity = "MPC8xx watchdog",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user((void *)arg, &info, sizeof(info)))
			return -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		if (put_user(wdt_status, (int *)arg))
			return -EFAULT;
		wdt_status &= ~WDIOF_KEEPALIVEPING;
		break;

	case WDIOC_GETTEMP:
		return -EOPNOTSUPP;

	case WDIOC_SETOPTIONS:
		return -EOPNOTSUPP;

	case WDIOC_KEEPALIVE:
		spin_lock(&wdt_lock);
		m8xx_wdt_reset();
		wdt_status |= WDIOF_KEEPALIVEPING;
		spin_unlock(&wdt_lock);
		break;

	case WDIOC_SETTIMEOUT:
		return -EOPNOTSUPP;

	case WDIOC_GETTIMEOUT:
		spin_lock(&wdt_lock);
		timeout = m8xx_wdt_get_timeout();
		spin_unlock(&wdt_lock);
		if (put_user(timeout, (int *)arg))
			return -EFAULT;
		break;

	default:
		return -ENOTTY;
	}

	return 0;
}

static const struct file_operations mpc8xx_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = mpc8xx_wdt_write,
	.unlocked_ioctl = mpc8xx_wdt_ioctl,
	.open = mpc8xx_wdt_open,
	.release = mpc8xx_wdt_release,
};

static struct miscdevice mpc8xx_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &mpc8xx_wdt_fops,
};

static int __init mpc8xx_wdt_init(void)
{
	spin_lock_init(&wdt_lock);
	return misc_register(&mpc8xx_wdt_miscdev);
}

static void __exit mpc8xx_wdt_exit(void)
{
	misc_deregister(&mpc8xx_wdt_miscdev);

	m8xx_wdt_reset();
	mpc8xx_wdt_handler_enable();
}

module_init(mpc8xx_wdt_init);
module_exit(mpc8xx_wdt_exit);

MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
MODULE_DESCRIPTION("MPC8xx watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* mpc8xx_wdt.c - MPC8xx watchdog userspace interface
	3	*
	4	* Author: Florian Schirmer <jolt@tuxbox.org>
	5	*
	6	* 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
	7	* the terms of the GNU General Public License version 2. This program
	8	* is licensed "as is" without any warranty of any kind, whether express
	9	* or implied.
	10	*/
	11
1da177e4 LT	12	#include <linux/fs.h>
	13	#include <linux/init.h>
	14	#include <linux/kernel.h>
	15	#include <linux/miscdevice.h>
	16	#include <linux/module.h>
	17	#include <linux/watchdog.h>
	18	#include <asm/8xx_immap.h>
f26ef3dc AC	19	#include <linux/uaccess.h>
f26ef3dc AC	20	#include <linux/io.h>
1da177e4 LT	21	#include <syslib/m8xx_wdt.h>
	22
	23	static unsigned long wdt_opened;
	24	static int wdt_status;
f26ef3dc	25	static spinlock_t wdt_lock;
1da177e4 LT	26
	27	static void mpc8xx_wdt_handler_disable(void)
	28	{
398f6858	29	volatile uint __iomem *piscr;
f26ef3dc	30	piscr = (uint )&((immap_t )IMAP_ADDR)->im_sit.sit_piscr;
1da177e4	31
fb64c244 MT	32	if (!m8xx_has_internal_rtc)
	33	m8xx_wdt_stop_timer();
	34	else
398f6858	35	out_be32(piscr, in_be32(piscr) & ~(PISCR_PIE \| PISCR_PTE));
1da177e4 LT	36	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
	37	}
	38
	39	static void mpc8xx_wdt_handler_enable(void)
	40	{
398f6858	41	volatile uint __iomem *piscr;
f26ef3dc	42	piscr = (uint )&((immap_t )IMAP_ADDR)->im_sit.sit_piscr;
1da177e4	43
fb64c244 MT	44	if (!m8xx_has_internal_rtc)
	45	m8xx_wdt_install_timer();
	46	else
398f6858	47	out_be32(piscr, in_be32(piscr) \| PISCR_PIE \| PISCR_PTE);
1da177e4 LT	48	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
	49	}
	50
	51	static int mpc8xx_wdt_open(struct inode inode, struct file file)
	52	{
	53	if (test_and_set_bit(0, &wdt_opened))
	54	return -EBUSY;
1da177e4 LT	55	m8xx_wdt_reset();
1da177e4 LT	56	mpc8xx_wdt_handler_disable();
ec9505a7	57	return nonseekable_open(inode, file);
1da177e4 LT	58	}
	59
	60	static int mpc8xx_wdt_release(struct inode inode, struct file file)
	61	{
	62	m8xx_wdt_reset();
1da177e4 LT	63	#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
	64	mpc8xx_wdt_handler_enable();
	65	#endif
1da177e4	66	clear_bit(0, &wdt_opened);
1da177e4 LT	67	return 0;
	68	}
	69
f26ef3dc AC	70	static ssize_t mpc8xx_wdt_write(struct file file, const char data,
f26ef3dc AC	71	size_t len, loff_t *ppos)
1da177e4	72	{
f26ef3dc AC	73	if (len) {
f26ef3dc AC	74	spin_lock(&wdt_lock);
1da177e4	75	m8xx_wdt_reset();
f26ef3dc AC	76	spin_unlock(&wdt_lock);
f26ef3dc AC	77	}
1da177e4 LT	78	return len;
	79	}
	80
f26ef3dc AC	81	static long mpc8xx_wdt_ioctl(struct file *file,
f26ef3dc AC	82	unsigned int cmd, unsigned long arg)
1da177e4 LT	83	{
	84	int timeout;
	85	static struct watchdog_info info = {
	86	.options = WDIOF_KEEPALIVEPING,
	87	.firmware_version = 0,
	88	.identity = "MPC8xx watchdog",
	89	};
	90
	91	switch (cmd) {
	92	case WDIOC_GETSUPPORT:
	93	if (copy_to_user((void *)arg, &info, sizeof(info)))
	94	return -EFAULT;
	95	break;
	96
	97	case WDIOC_GETSTATUS:
	98	case WDIOC_GETBOOTSTATUS:
	99	if (put_user(wdt_status, (int *)arg))
	100	return -EFAULT;
	101	wdt_status &= ~WDIOF_KEEPALIVEPING;
	102	break;
	103
	104	case WDIOC_GETTEMP:
	105	return -EOPNOTSUPP;
	106
	107	case WDIOC_SETOPTIONS:
	108	return -EOPNOTSUPP;
	109
	110	case WDIOC_KEEPALIVE:
f26ef3dc	111	spin_lock(&wdt_lock);
1da177e4 LT	112	m8xx_wdt_reset();
1da177e4 LT	113	wdt_status \|= WDIOF_KEEPALIVEPING;
f26ef3dc	114	spin_unlock(&wdt_lock);
1da177e4 LT	115	break;
	116
	117	case WDIOC_SETTIMEOUT:
	118	return -EOPNOTSUPP;
	119
	120	case WDIOC_GETTIMEOUT:
f26ef3dc	121	spin_lock(&wdt_lock);
1da177e4	122	timeout = m8xx_wdt_get_timeout();
f26ef3dc	123	spin_unlock(&wdt_lock);
1da177e4 LT	124	if (put_user(timeout, (int *)arg))
	125	return -EFAULT;
	126	break;
	127
	128	default:
795b89d2	129	return -ENOTTY;
1da177e4 LT	130	}
	131
	132	return 0;
	133	}
	134
62322d25	135	static const struct file_operations mpc8xx_wdt_fops = {
1da177e4 LT	136	.owner = THIS_MODULE,
	137	.llseek = no_llseek,
	138	.write = mpc8xx_wdt_write,
f26ef3dc	139	.unlocked_ioctl = mpc8xx_wdt_ioctl,
1da177e4 LT	140	.open = mpc8xx_wdt_open,
	141	.release = mpc8xx_wdt_release,
	142	};
	143
	144	static struct miscdevice mpc8xx_wdt_miscdev = {
	145	.minor = WATCHDOG_MINOR,
	146	.name = "watchdog",
	147	.fops = &mpc8xx_wdt_fops,
	148	};
	149
	150	static int __init mpc8xx_wdt_init(void)
	151	{
f26ef3dc	152	spin_lock_init(&wdt_lock);
1da177e4 LT	153	return misc_register(&mpc8xx_wdt_miscdev);
	154	}
	155
	156	static void __exit mpc8xx_wdt_exit(void)
	157	{
	158	misc_deregister(&mpc8xx_wdt_miscdev);
	159
	160	m8xx_wdt_reset();
	161	mpc8xx_wdt_handler_enable();
	162	}
	163
	164	module_init(mpc8xx_wdt_init);
	165	module_exit(mpc8xx_wdt_exit);
	166
	167	MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
	168	MODULE_DESCRIPTION("MPC8xx watchdog driver");
	169	MODULE_LICENSE("GPL");
	170	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);