[net-next-2.6.git] / drivers / char / watchdog / mv64x60_wdt.c

/*
 * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
 *
 * Author: James Chapman <jchapman@katalix.com>
 *
 * Platform-specific setup code should configure the dog to generate
 * interrupt or reset as required.  This code only enables/disables
 * and services the watchdog.
 *
 * Derived from mpc8xx_wdt.c, with the following copyright.
 * 
 * 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 <linux/platform_device.h>

#include <linux/mv643xx.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define MV64x60_WDT_WDC_OFFSET	0

/* MV64x60 WDC (config) register access definitions */
#define MV64x60_WDC_CTL1_MASK	(3 << 24)
#define MV64x60_WDC_CTL1(val)	((val & 3) << 24)
#define MV64x60_WDC_CTL2_MASK	(3 << 26)
#define MV64x60_WDC_CTL2(val)	((val & 3) << 26)

/* Flags bits */
#define MV64x60_WDOG_FLAG_OPENED	0
#define MV64x60_WDOG_FLAG_ENABLED	1

static unsigned long wdt_flags;
static int wdt_status;
static void __iomem *mv64x60_wdt_regs;
static int mv64x60_wdt_timeout;

static void mv64x60_wdt_reg_write(u32 val)
{
	/* Allow write only to CTL1 / CTL2 fields, retaining values in
	 * other fields.
	 */
	u32 data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
	data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
	data |= val;
	writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
}

static void mv64x60_wdt_service(void)
{
	/* Write 01 followed by 10 to CTL2 */
	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
}

static void mv64x60_wdt_handler_disable(void)
{
	if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
		/* Write 01 followed by 10 to CTL1 */
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
		printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
	}
}

static void mv64x60_wdt_handler_enable(void)
{
	if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
		/* Write 01 followed by 10 to CTL1 */
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
		printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
	}
}

static int mv64x60_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
		return -EBUSY;

	mv64x60_wdt_service();
	mv64x60_wdt_handler_enable();

	return nonseekable_open(inode, file);
}

static int mv64x60_wdt_release(struct inode *inode, struct file *file)
{
	mv64x60_wdt_service();

#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
	mv64x60_wdt_handler_disable();
#endif

	clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);

	return 0;
}

static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
				 size_t len, loff_t * ppos)
{
	if (len)
		mv64x60_wdt_service();

	return len;
}

static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
			     unsigned int cmd, unsigned long arg)
{
	int timeout;
	void __user *argp = (void __user *)arg;
	static struct watchdog_info info = {
		.options = WDIOF_KEEPALIVEPING,
		.firmware_version = 0,
		.identity = "MV64x60 watchdog",
	};

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

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

	case WDIOC_GETTEMP:
		return -EOPNOTSUPP;

	case WDIOC_SETOPTIONS:
		return -EOPNOTSUPP;

	case WDIOC_KEEPALIVE:
		mv64x60_wdt_service();
		wdt_status |= WDIOF_KEEPALIVEPING;
		break;

	case WDIOC_SETTIMEOUT:
		return -EOPNOTSUPP;

	case WDIOC_GETTIMEOUT:
		timeout = mv64x60_wdt_timeout * HZ;
		if (put_user(timeout, (int __user *)argp))
			return -EFAULT;
		break;

	default:
		return -ENOTTY;
	}

	return 0;
}

static const struct file_operations mv64x60_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = mv64x60_wdt_write,
	.ioctl = mv64x60_wdt_ioctl,
	.open = mv64x60_wdt_open,
	.release = mv64x60_wdt_release,
};

static struct miscdevice mv64x60_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &mv64x60_wdt_fops,
};

static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
{
	struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
	int bus_clk = 133;
	struct resource *r;

	mv64x60_wdt_timeout = 10;
	if (pdata) {
		mv64x60_wdt_timeout = pdata->timeout;
		bus_clk = pdata->bus_clk;
	}

	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!r)
		return -ENODEV;

	mv64x60_wdt_regs = ioremap(r->start, r->end - r->start + 1);
	if (mv64x60_wdt_regs == NULL)
		return -ENOMEM;

	writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
	       mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);

	return misc_register(&mv64x60_wdt_miscdev);
}

static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
{
	misc_deregister(&mv64x60_wdt_miscdev);

	mv64x60_wdt_service();
	mv64x60_wdt_handler_disable();

	iounmap(mv64x60_wdt_regs);

	return 0;
}

static struct platform_driver mv64x60_wdt_driver = {
	.probe = mv64x60_wdt_probe,
	.remove = __devexit_p(mv64x60_wdt_remove),
	.driver = {
		.owner = THIS_MODULE,
		.name = MV64x60_WDT_NAME,
	},
};

static int __init mv64x60_wdt_init(void)
{
	printk(KERN_INFO "MV64x60 watchdog driver\n");

	return platform_driver_register(&mv64x60_wdt_driver);
}

static void __exit mv64x60_wdt_exit(void)
{
	platform_driver_unregister(&mv64x60_wdt_driver);
}

module_init(mv64x60_wdt_init);
module_exit(mv64x60_wdt_exit);

MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("MV64x60 watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
3be10211 JC	1	/*
	2	* mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
	3	*
	4	* Author: James Chapman <jchapman@katalix.com>
	5	*
	6	* Platform-specific setup code should configure the dog to generate
	7	* interrupt or reset as required. This code only enables/disables
	8	* and services the watchdog.
	9	*
	10	* Derived from mpc8xx_wdt.c, with the following copyright.
	11	*
	12	* 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
	13	* the terms of the GNU General Public License version 2. This program
	14	* is licensed "as is" without any warranty of any kind, whether express
	15	* or implied.
	16	*/
	17
3be10211 JC	18	#include <linux/fs.h>
	19	#include <linux/init.h>
	20	#include <linux/kernel.h>
	21	#include <linux/miscdevice.h>
	22	#include <linux/module.h>
	23	#include <linux/watchdog.h>
d052d1be RK	24	#include <linux/platform_device.h>
d052d1be RK	25
7e07a159	26	#include <linux/mv643xx.h>
3be10211 JC	27	#include <asm/uaccess.h>
	28	#include <asm/io.h>
	29
8a5cfa64 DF	30	#define MV64x60_WDT_WDC_OFFSET 0
8a5cfa64 DF	31
3be10211 JC	32	/* MV64x60 WDC (config) register access definitions */
	33	#define MV64x60_WDC_CTL1_MASK (3 << 24)
	34	#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
	35	#define MV64x60_WDC_CTL2_MASK (3 << 26)
	36	#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
	37
	38	/* Flags bits */
	39	#define MV64x60_WDOG_FLAG_OPENED 0
	40	#define MV64x60_WDOG_FLAG_ENABLED 1
	41
	42	static unsigned long wdt_flags;
	43	static int wdt_status;
8a5cfa64	44	static void __iomem *mv64x60_wdt_regs;
3be10211 JC	45	static int mv64x60_wdt_timeout;
	46
	47	static void mv64x60_wdt_reg_write(u32 val)
	48	{
	49	/* Allow write only to CTL1 / CTL2 fields, retaining values in
	50	* other fields.
	51	*/
8a5cfa64	52	u32 data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
3be10211 JC	53	data &= ~(MV64x60_WDC_CTL1_MASK \| MV64x60_WDC_CTL2_MASK);
3be10211 JC	54	data \|= val;
8a5cfa64	55	writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
3be10211 JC	56	}
	57
	58	static void mv64x60_wdt_service(void)
	59	{
	60	/* Write 01 followed by 10 to CTL2 */
	61	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
	62	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
	63	}
	64
	65	static void mv64x60_wdt_handler_disable(void)
	66	{
	67	if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
	68	/* Write 01 followed by 10 to CTL1 */
	69	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
	70	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
	71	printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
	72	}
	73	}
	74
	75	static void mv64x60_wdt_handler_enable(void)
	76	{
	77	if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
	78	/* Write 01 followed by 10 to CTL1 */
	79	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
	80	mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
	81	printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
	82	}
	83	}
	84
	85	static int mv64x60_wdt_open(struct inode inode, struct file file)
	86	{
	87	if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
	88	return -EBUSY;
	89
	90	mv64x60_wdt_service();
	91	mv64x60_wdt_handler_enable();
	92
861e5137	93	return nonseekable_open(inode, file);
3be10211 JC	94	}
	95
	96	static int mv64x60_wdt_release(struct inode inode, struct file file)
	97	{
	98	mv64x60_wdt_service();
	99
	100	#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
	101	mv64x60_wdt_handler_disable();
	102	#endif
	103
	104	clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
	105
	106	return 0;
	107	}
	108
b2846dfa	109	static ssize_t mv64x60_wdt_write(struct file file, const char __user data,
3be10211 JC	110	size_t len, loff_t * ppos)
3be10211 JC	111	{
3be10211 JC	112	if (len)
	113	mv64x60_wdt_service();
	114
	115	return len;
	116	}
	117
	118	static int mv64x60_wdt_ioctl(struct inode inode, struct file file,
	119	unsigned int cmd, unsigned long arg)
	120	{
	121	int timeout;
b2846dfa	122	void __user argp = (void __user )arg;
3be10211 JC	123	static struct watchdog_info info = {
	124	.options = WDIOF_KEEPALIVEPING,
	125	.firmware_version = 0,
	126	.identity = "MV64x60 watchdog",
	127	};
	128
	129	switch (cmd) {
	130	case WDIOC_GETSUPPORT:
b2846dfa	131	if (copy_to_user(argp, &info, sizeof(info)))
3be10211 JC	132	return -EFAULT;
	133	break;
	134
	135	case WDIOC_GETSTATUS:
	136	case WDIOC_GETBOOTSTATUS:
b2846dfa	137	if (put_user(wdt_status, (int __user *)argp))
3be10211 JC	138	return -EFAULT;
	139	wdt_status &= ~WDIOF_KEEPALIVEPING;
	140	break;
	141
	142	case WDIOC_GETTEMP:
	143	return -EOPNOTSUPP;
	144
	145	case WDIOC_SETOPTIONS:
	146	return -EOPNOTSUPP;
	147
	148	case WDIOC_KEEPALIVE:
	149	mv64x60_wdt_service();
	150	wdt_status \|= WDIOF_KEEPALIVEPING;
	151	break;
	152
	153	case WDIOC_SETTIMEOUT:
	154	return -EOPNOTSUPP;
	155
	156	case WDIOC_GETTIMEOUT:
	157	timeout = mv64x60_wdt_timeout * HZ;
b2846dfa	158	if (put_user(timeout, (int __user *)argp))
3be10211 JC	159	return -EFAULT;
	160	break;
	161
	162	default:
795b89d2	163	return -ENOTTY;
3be10211 JC	164	}
	165
	166	return 0;
	167	}
	168
62322d25	169	static const struct file_operations mv64x60_wdt_fops = {
3be10211 JC	170	.owner = THIS_MODULE,
	171	.llseek = no_llseek,
	172	.write = mv64x60_wdt_write,
	173	.ioctl = mv64x60_wdt_ioctl,
	174	.open = mv64x60_wdt_open,
	175	.release = mv64x60_wdt_release,
	176	};
	177
	178	static struct miscdevice mv64x60_wdt_miscdev = {
	179	.minor = WATCHDOG_MINOR,
	180	.name = "watchdog",
	181	.fops = &mv64x60_wdt_fops,
	182	};
	183
3ae5eaec	184	static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
3be10211	185	{
3ae5eaec	186	struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
3be10211	187	int bus_clk = 133;
8a5cfa64	188	struct resource *r;
3be10211 JC	189
	190	mv64x60_wdt_timeout = 10;
	191	if (pdata) {
	192	mv64x60_wdt_timeout = pdata->timeout;
	193	bus_clk = pdata->bus_clk;
	194	}
	195
8a5cfa64 DF	196	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
	197	if (!r)
	198	return -ENODEV;
	199
	200	mv64x60_wdt_regs = ioremap(r->start, r->end - r->start + 1);
	201	if (mv64x60_wdt_regs == NULL)
	202	return -ENOMEM;
3be10211 JC	203
3be10211 JC	204	writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
8a5cfa64	205	mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
3be10211 JC	206
	207	return misc_register(&mv64x60_wdt_miscdev);
	208	}
	209
3ae5eaec	210	static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
3be10211 JC	211	{
	212	misc_deregister(&mv64x60_wdt_miscdev);
	213
	214	mv64x60_wdt_service();
	215	mv64x60_wdt_handler_disable();
	216
8a5cfa64 DF	217	iounmap(mv64x60_wdt_regs);
8a5cfa64 DF	218
3be10211 JC	219	return 0;
	220	}
	221
3ae5eaec	222	static struct platform_driver mv64x60_wdt_driver = {
3be10211 JC	223	.probe = mv64x60_wdt_probe,
3be10211 JC	224	.remove = __devexit_p(mv64x60_wdt_remove),
3ae5eaec RK	225	.driver = {
	226	.owner = THIS_MODULE,
	227	.name = MV64x60_WDT_NAME,
	228	},
3be10211 JC	229	};
3be10211 JC	230
3be10211 JC	231	static int __init mv64x60_wdt_init(void)
3be10211 JC	232	{
3be10211 JC	233	printk(KERN_INFO "MV64x60 watchdog driver\n");
3be10211 JC	234
422db8d2	235	return platform_driver_register(&mv64x60_wdt_driver);
3be10211 JC	236	}
	237
	238	static void __exit mv64x60_wdt_exit(void)
	239	{
3ae5eaec	240	platform_driver_unregister(&mv64x60_wdt_driver);
3be10211 JC	241	}
	242
	243	module_init(mv64x60_wdt_init);
	244	module_exit(mv64x60_wdt_exit);
	245
	246	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	247	MODULE_DESCRIPTION("MV64x60 watchdog driver");
	248	MODULE_LICENSE("GPL");
	249	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);