[mirror_ubuntu-zesty-kernel.git] / drivers / watchdog / rdc321x_wdt.c

/*
 * RDC321x watchdog driver
 *
 * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
 *
 * This driver is highly inspired from the cpu5_wdt driver
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/mfd/rdc321x.h>

#define RDC_WDT_MASK	0x80000000 /* Mask */
#define RDC_WDT_EN	0x00800000 /* Enable bit */
#define RDC_WDT_WTI	0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
#define RDC_WDT_RST	0x00100000 /* Reset bit */
#define RDC_WDT_WIF	0x00040000 /* WDT IRQ Flag */
#define RDC_WDT_IRT	0x00000100 /* IRQ Routing table */
#define RDC_WDT_CNT	0x00000001 /* WDT count */

#define RDC_CLS_TMR	0x80003844 /* Clear timer */

#define RDC_WDT_INTERVAL	(HZ/10+1)

static int ticks = 1000;

/* some device data */

static struct {
	struct completion stop;
	int running;
	struct timer_list timer;
	int queue;
	int default_ticks;
	unsigned long inuse;
	spinlock_t lock;
	struct pci_dev *sb_pdev;
	int base_reg;
} rdc321x_wdt_device;

/* generic helper functions */

static void rdc321x_wdt_trigger(unsigned long unused)
{
	unsigned long flags;
	u32 val;

	if (rdc321x_wdt_device.running)
		ticks--;

	/* keep watchdog alive */
	spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
	pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
					rdc321x_wdt_device.base_reg, &val);
	val |= RDC_WDT_EN;
	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
					rdc321x_wdt_device.base_reg, val);
	spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);

	/* requeue?? */
	if (rdc321x_wdt_device.queue && ticks)
		mod_timer(&rdc321x_wdt_device.timer,
				jiffies + RDC_WDT_INTERVAL);
	else {
		/* ticks doesn't matter anyway */
		complete(&rdc321x_wdt_device.stop);
	}

}

static void rdc321x_wdt_reset(void)
{
	ticks = rdc321x_wdt_device.default_ticks;
}

static void rdc321x_wdt_start(void)
{
	unsigned long flags;

	if (!rdc321x_wdt_device.queue) {
		rdc321x_wdt_device.queue = 1;

		/* Clear the timer */
		spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
		pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
				rdc321x_wdt_device.base_reg, RDC_CLS_TMR);

		/* Enable watchdog and set the timeout to 81.92 us */
		pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
					rdc321x_wdt_device.base_reg,
					RDC_WDT_EN | RDC_WDT_CNT);
		spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);

		mod_timer(&rdc321x_wdt_device.timer,
				jiffies + RDC_WDT_INTERVAL);
	}

	/* if process dies, counter is not decremented */
	rdc321x_wdt_device.running++;
}

static int rdc321x_wdt_stop(void)
{
	if (rdc321x_wdt_device.running)
		rdc321x_wdt_device.running = 0;

	ticks = rdc321x_wdt_device.default_ticks;

	return -EIO;
}

/* filesystem operations */
static int rdc321x_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
		return -EBUSY;

	return nonseekable_open(inode, file);
}

static int rdc321x_wdt_release(struct inode *inode, struct file *file)
{
	clear_bit(0, &rdc321x_wdt_device.inuse);
	return 0;
}

static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	u32 value;
	static const struct watchdog_info ident = {
		.options = WDIOF_CARDRESET,
		.identity = "RDC321x WDT",
	};
	unsigned long flags;

	switch (cmd) {
	case WDIOC_KEEPALIVE:
		rdc321x_wdt_reset();
		break;
	case WDIOC_GETSTATUS:
		/* Read the value from the DATA register */
		spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
		pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
					rdc321x_wdt_device.base_reg, &value);
		spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
		if (copy_to_user(argp, &value, sizeof(u32)))
			return -EFAULT;
		break;
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		break;
	case WDIOC_SETOPTIONS:
		if (copy_from_user(&value, argp, sizeof(int)))
			return -EFAULT;
		switch (value) {
		case WDIOS_ENABLECARD:
			rdc321x_wdt_start();
			break;
		case WDIOS_DISABLECARD:
			return rdc321x_wdt_stop();
		default:
			return -EINVAL;
		}
		break;
	default:
		return -ENOTTY;
	}
	return 0;
}

static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
				size_t count, loff_t *ppos)
{
	if (!count)
		return -EIO;

	rdc321x_wdt_reset();

	return count;
}

static const struct file_operations rdc321x_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.unlocked_ioctl	= rdc321x_wdt_ioctl,
	.open		= rdc321x_wdt_open,
	.write		= rdc321x_wdt_write,
	.release	= rdc321x_wdt_release,
};

static struct miscdevice rdc321x_wdt_misc = {
	.minor	= WATCHDOG_MINOR,
	.name	= "watchdog",
	.fops	= &rdc321x_wdt_fops,
};

static int rdc321x_wdt_probe(struct platform_device *pdev)
{
	int err;
	struct resource *r;
	struct rdc321x_wdt_pdata *pdata;

	pdata = dev_get_platdata(&pdev->dev);
	if (!pdata) {
		dev_err(&pdev->dev, "no platform data supplied\n");
		return -ENODEV;
	}

	r = platform_get_resource_byname(pdev, IORESOURCE_IO, "wdt-reg");
	if (!r) {
		dev_err(&pdev->dev, "failed to get wdt-reg resource\n");
		return -ENODEV;
	}

	rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
	rdc321x_wdt_device.base_reg = r->start;

	err = misc_register(&rdc321x_wdt_misc);
	if (err < 0) {
		dev_err(&pdev->dev, "misc_register failed\n");
		return err;
	}

	spin_lock_init(&rdc321x_wdt_device.lock);

	/* Reset the watchdog */
	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
				rdc321x_wdt_device.base_reg, RDC_WDT_RST);

	init_completion(&rdc321x_wdt_device.stop);
	rdc321x_wdt_device.queue = 0;

	clear_bit(0, &rdc321x_wdt_device.inuse);

	setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);

	rdc321x_wdt_device.default_ticks = ticks;

	dev_info(&pdev->dev, "watchdog init success\n");

	return 0;
}

static int rdc321x_wdt_remove(struct platform_device *pdev)
{
	if (rdc321x_wdt_device.queue) {
		rdc321x_wdt_device.queue = 0;
		wait_for_completion(&rdc321x_wdt_device.stop);
	}

	misc_deregister(&rdc321x_wdt_misc);

	return 0;
}

static struct platform_driver rdc321x_wdt_driver = {
	.probe = rdc321x_wdt_probe,
	.remove = rdc321x_wdt_remove,
	.driver = {
		.name = "rdc321x-wdt",
	},
};

module_platform_driver(rdc321x_wdt_driver);

MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x watchdog driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
b3e8f2c1 FF	1	/*
	2	* RDC321x watchdog driver
	3	*
842102f3	4	* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
b3e8f2c1 FF	5	*
	6	* This driver is highly inspired from the cpu5_wdt driver
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	21	*
	22	*/
	23
	24	#include <linux/module.h>
	25	#include <linux/moduleparam.h>
	26	#include <linux/types.h>
	27	#include <linux/errno.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/fs.h>
b3e8f2c1 FF	30	#include <linux/ioport.h>
	31	#include <linux/timer.h>
	32	#include <linux/completion.h>
	33	#include <linux/jiffies.h>
	34	#include <linux/platform_device.h>
	35	#include <linux/watchdog.h>
	36	#include <linux/io.h>
	37	#include <linux/uaccess.h>
842102f3	38	#include <linux/mfd/rdc321x.h>
b3e8f2c1 FF	39
	40	#define RDC_WDT_MASK 0x80000000 /* Mask */
	41	#define RDC_WDT_EN 0x00800000 /* Enable bit */
	42	#define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
	43	#define RDC_WDT_RST 0x00100000 /* Reset bit */
	44	#define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
	45	#define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
	46	#define RDC_WDT_CNT 0x00000001 /* WDT count */
	47
	48	#define RDC_CLS_TMR 0x80003844 /* Clear timer */
	49
	50	#define RDC_WDT_INTERVAL (HZ/10+1)
	51
	52	static int ticks = 1000;
	53
	54	/* some device data */
	55
	56	static struct {
	57	struct completion stop;
	58	int running;
	59	struct timer_list timer;
	60	int queue;
	61	int default_ticks;
	62	unsigned long inuse;
	63	spinlock_t lock;
842102f3 FF	64	struct pci_dev *sb_pdev;
842102f3 FF	65	int base_reg;
b3e8f2c1 FF	66	} rdc321x_wdt_device;
	67
	68	/* generic helper functions */
	69
	70	static void rdc321x_wdt_trigger(unsigned long unused)
	71	{
	72	unsigned long flags;
842102f3	73	u32 val;
b3e8f2c1 FF	74
	75	if (rdc321x_wdt_device.running)
	76	ticks--;
	77
	78	/* keep watchdog alive */
	79	spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
842102f3 FF	80	pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
	81	rdc321x_wdt_device.base_reg, &val);
	82	val \|= RDC_WDT_EN;
	83	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
	84	rdc321x_wdt_device.base_reg, val);
b3e8f2c1 FF	85	spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
	86
	87	/* requeue?? */
	88	if (rdc321x_wdt_device.queue && ticks)
	89	mod_timer(&rdc321x_wdt_device.timer,
	90	jiffies + RDC_WDT_INTERVAL);
	91	else {
	92	/* ticks doesn't matter anyway */
	93	complete(&rdc321x_wdt_device.stop);
	94	}
	95
	96	}
	97
	98	static void rdc321x_wdt_reset(void)
	99	{
	100	ticks = rdc321x_wdt_device.default_ticks;
	101	}
	102
	103	static void rdc321x_wdt_start(void)
	104	{
	105	unsigned long flags;
	106
	107	if (!rdc321x_wdt_device.queue) {
	108	rdc321x_wdt_device.queue = 1;
	109
	110	/* Clear the timer */
	111	spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
842102f3 FF	112	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
842102f3 FF	113	rdc321x_wdt_device.base_reg, RDC_CLS_TMR);
b3e8f2c1 FF	114
b3e8f2c1 FF	115	/* Enable watchdog and set the timeout to 81.92 us */
842102f3 FF	116	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
	117	rdc321x_wdt_device.base_reg,
	118	RDC_WDT_EN \| RDC_WDT_CNT);
b3e8f2c1 FF	119	spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
	120
	121	mod_timer(&rdc321x_wdt_device.timer,
	122	jiffies + RDC_WDT_INTERVAL);
	123	}
	124
	125	/* if process dies, counter is not decremented */
	126	rdc321x_wdt_device.running++;
	127	}
	128
	129	static int rdc321x_wdt_stop(void)
	130	{
	131	if (rdc321x_wdt_device.running)
	132	rdc321x_wdt_device.running = 0;
	133
	134	ticks = rdc321x_wdt_device.default_ticks;
	135
	136	return -EIO;
	137	}
	138
	139	/* filesystem operations */
	140	static int rdc321x_wdt_open(struct inode inode, struct file file)
	141	{
	142	if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
	143	return -EBUSY;
	144
	145	return nonseekable_open(inode, file);
	146	}
	147
	148	static int rdc321x_wdt_release(struct inode inode, struct file file)
	149	{
	150	clear_bit(0, &rdc321x_wdt_device.inuse);
	151	return 0;
	152	}
	153
7275fc8c WVS	154	static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd,
7275fc8c WVS	155	unsigned long arg)
b3e8f2c1 FF	156	{
b3e8f2c1 FF	157	void __user argp = (void __user )arg;
842102f3	158	u32 value;
42747d71	159	static const struct watchdog_info ident = {
b3e8f2c1 FF	160	.options = WDIOF_CARDRESET,
	161	.identity = "RDC321x WDT",
	162	};
	163	unsigned long flags;
	164
	165	switch (cmd) {
	166	case WDIOC_KEEPALIVE:
	167	rdc321x_wdt_reset();
	168	break;
	169	case WDIOC_GETSTATUS:
	170	/* Read the value from the DATA register */
	171	spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
842102f3 FF	172	pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
842102f3 FF	173	rdc321x_wdt_device.base_reg, &value);
b3e8f2c1	174	spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
842102f3	175	if (copy_to_user(argp, &value, sizeof(u32)))
b3e8f2c1 FF	176	return -EFAULT;
	177	break;
	178	case WDIOC_GETSUPPORT:
	179	if (copy_to_user(argp, &ident, sizeof(ident)))
	180	return -EFAULT;
	181	break;
	182	case WDIOC_SETOPTIONS:
	183	if (copy_from_user(&value, argp, sizeof(int)))
	184	return -EFAULT;
	185	switch (value) {
	186	case WDIOS_ENABLECARD:
	187	rdc321x_wdt_start();
	188	break;
	189	case WDIOS_DISABLECARD:
	190	return rdc321x_wdt_stop();
	191	default:
	192	return -EINVAL;
	193	}
	194	break;
	195	default:
	196	return -ENOTTY;
	197	}
	198	return 0;
	199	}
	200
	201	static ssize_t rdc321x_wdt_write(struct file file, const char __user buf,
	202	size_t count, loff_t *ppos)
	203	{
	204	if (!count)
	205	return -EIO;
	206
	207	rdc321x_wdt_reset();
	208
	209	return count;
	210	}
	211
	212	static const struct file_operations rdc321x_wdt_fops = {
	213	.owner = THIS_MODULE,
	214	.llseek = no_llseek,
7275fc8c	215	.unlocked_ioctl = rdc321x_wdt_ioctl,
b3e8f2c1 FF	216	.open = rdc321x_wdt_open,
	217	.write = rdc321x_wdt_write,
	218	.release = rdc321x_wdt_release,
	219	};
	220
	221	static struct miscdevice rdc321x_wdt_misc = {
	222	.minor = WATCHDOG_MINOR,
	223	.name = "watchdog",
	224	.fops = &rdc321x_wdt_fops,
	225	};
	226
2d991a16	227	static int rdc321x_wdt_probe(struct platform_device *pdev)
b3e8f2c1 FF	228	{
b3e8f2c1 FF	229	int err;
842102f3 FF	230	struct resource *r;
	231	struct rdc321x_wdt_pdata *pdata;
	232
bc8fdfbe	233	pdata = dev_get_platdata(&pdev->dev);
842102f3 FF	234	if (!pdata) {
	235	dev_err(&pdev->dev, "no platform data supplied\n");
	236	return -ENODEV;
	237	}
	238
8deca39e	239	r = platform_get_resource_byname(pdev, IORESOURCE_IO, "wdt-reg");
842102f3 FF	240	if (!r) {
	241	dev_err(&pdev->dev, "failed to get wdt-reg resource\n");
	242	return -ENODEV;
	243	}
	244
	245	rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
	246	rdc321x_wdt_device.base_reg = r->start;
b3e8f2c1 FF	247
	248	err = misc_register(&rdc321x_wdt_misc);
	249	if (err < 0) {
842102f3	250	dev_err(&pdev->dev, "misc_register failed\n");
b3e8f2c1 FF	251	return err;
	252	}
	253
	254	spin_lock_init(&rdc321x_wdt_device.lock);
	255
	256	/* Reset the watchdog */
842102f3 FF	257	pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
842102f3 FF	258	rdc321x_wdt_device.base_reg, RDC_WDT_RST);
b3e8f2c1 FF	259
	260	init_completion(&rdc321x_wdt_device.stop);
	261	rdc321x_wdt_device.queue = 0;
	262
	263	clear_bit(0, &rdc321x_wdt_device.inuse);
	264
	265	setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
	266
	267	rdc321x_wdt_device.default_ticks = ticks;
	268
842102f3	269	dev_info(&pdev->dev, "watchdog init success\n");
b3e8f2c1 FF	270
	271	return 0;
	272	}
	273
4b12b896	274	static int rdc321x_wdt_remove(struct platform_device *pdev)
b3e8f2c1 FF	275	{
	276	if (rdc321x_wdt_device.queue) {
	277	rdc321x_wdt_device.queue = 0;
	278	wait_for_completion(&rdc321x_wdt_device.stop);
	279	}
	280
	281	misc_deregister(&rdc321x_wdt_misc);
	282
	283	return 0;
	284	}
	285
	286	static struct platform_driver rdc321x_wdt_driver = {
	287	.probe = rdc321x_wdt_probe,
82268714	288	.remove = rdc321x_wdt_remove,
b3e8f2c1	289	.driver = {
b3e8f2c1 FF	290	.name = "rdc321x-wdt",
	291	},
	292	};
	293
b8ec6118	294	module_platform_driver(rdc321x_wdt_driver);
b3e8f2c1 FF	295
	296	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	297	MODULE_DESCRIPTION("RDC321x watchdog driver");
	298	MODULE_LICENSE("GPL");