[deliverable/linux.git] / drivers / watchdog / adx_wdt.c

/*
 * Copyright (C) 2008-2009 Avionic Design GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/fs.h>
#include <linux/io.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>

#define WATCHDOG_NAME "adx-wdt"

/* register offsets */
#define	ADX_WDT_CONTROL		0x00
#define	ADX_WDT_CONTROL_ENABLE	(1 << 0)
#define	ADX_WDT_CONTROL_nRESET	(1 << 1)
#define	ADX_WDT_TIMEOUT		0x08

static struct platform_device *adx_wdt_dev;
static unsigned long driver_open;

#define	WDT_STATE_STOP	0
#define	WDT_STATE_START	1

struct adx_wdt {
	void __iomem *base;
	unsigned long timeout;
	unsigned int state;
	unsigned int wake;
	spinlock_t lock;
};

static const struct watchdog_info adx_wdt_info = {
	.identity = "Avionic Design Xanthos Watchdog",
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
};

static void adx_wdt_start_locked(struct adx_wdt *wdt)
{
	u32 ctrl;

	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	ctrl |= ADX_WDT_CONTROL_ENABLE;
	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	wdt->state = WDT_STATE_START;
}

static void adx_wdt_start(struct adx_wdt *wdt)
{
	unsigned long flags;

	spin_lock_irqsave(&wdt->lock, flags);
	adx_wdt_start_locked(wdt);
	spin_unlock_irqrestore(&wdt->lock, flags);
}

static void adx_wdt_stop_locked(struct adx_wdt *wdt)
{
	u32 ctrl;

	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	wdt->state = WDT_STATE_STOP;
}

static void adx_wdt_stop(struct adx_wdt *wdt)
{
	unsigned long flags;

	spin_lock_irqsave(&wdt->lock, flags);
	adx_wdt_stop_locked(wdt);
	spin_unlock_irqrestore(&wdt->lock, flags);
}

static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds)
{
	unsigned long timeout = seconds * 1000;
	unsigned long flags;
	unsigned int state;

	spin_lock_irqsave(&wdt->lock, flags);
	state = wdt->state;
	adx_wdt_stop_locked(wdt);
	writel(timeout, wdt->base + ADX_WDT_TIMEOUT);

	if (state == WDT_STATE_START)
		adx_wdt_start_locked(wdt);

	wdt->timeout = timeout;
	spin_unlock_irqrestore(&wdt->lock, flags);
}

static void adx_wdt_get_timeout(struct adx_wdt *wdt, unsigned long *seconds)
{
	*seconds = wdt->timeout / 1000;
}

static void adx_wdt_keepalive(struct adx_wdt *wdt)
{
	unsigned long flags;

	spin_lock_irqsave(&wdt->lock, flags);
	writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT);
	spin_unlock_irqrestore(&wdt->lock, flags);
}

static int adx_wdt_open(struct inode *inode, struct file *file)
{
	struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev);

	if (test_and_set_bit(0, &driver_open))
		return -EBUSY;

	file->private_data = wdt;
	adx_wdt_set_timeout(wdt, 30);
	adx_wdt_start(wdt);

	return nonseekable_open(inode, file);
}

static int adx_wdt_release(struct inode *inode, struct file *file)
{
	struct adx_wdt *wdt = file->private_data;

	adx_wdt_stop(wdt);
	clear_bit(0, &driver_open);

	return 0;
}

static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct adx_wdt *wdt = file->private_data;
	void __user *argp = (void __user *)arg;
	unsigned long __user *p = argp;
	unsigned long seconds = 0;
	unsigned int options;
	long ret = -EINVAL;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info)))
			return -EFAULT;
		else
			return 0;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_KEEPALIVE:
		adx_wdt_keepalive(wdt);
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(seconds, p))
			return -EFAULT;

		adx_wdt_set_timeout(wdt, seconds);

		/* fallthrough */
	case WDIOC_GETTIMEOUT:
		adx_wdt_get_timeout(wdt, &seconds);
		return put_user(seconds, p);

	case WDIOC_SETOPTIONS:
		if (copy_from_user(&options, argp, sizeof(options)))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			adx_wdt_stop(wdt);
			ret = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			adx_wdt_start(wdt);
			ret = 0;
		}

		return ret;

	default:
		break;
	}

	return -ENOTTY;
}

static ssize_t adx_wdt_write(struct file *file, const char __user *data,
		size_t len, loff_t *ppos)
{
	struct adx_wdt *wdt = file->private_data;

	if (len)
		adx_wdt_keepalive(wdt);

	return len;
}

static const struct file_operations adx_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.open = adx_wdt_open,
	.release = adx_wdt_release,
	.unlocked_ioctl = adx_wdt_ioctl,
	.write = adx_wdt_write,
};

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

static int __devinit adx_wdt_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct adx_wdt *wdt;
	int ret = 0;
	u32 ctrl;

	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	if (!wdt) {
		dev_err(&pdev->dev, "cannot allocate WDT structure\n");
		return -ENOMEM;
	}

	spin_lock_init(&wdt->lock);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "cannot obtain I/O memory region\n");
		return -ENXIO;
	}

	res = devm_request_mem_region(&pdev->dev, res->start,
			resource_size(res), res->name);
	if (!res) {
		dev_err(&pdev->dev, "cannot request I/O memory region\n");
		return -ENXIO;
	}

	wdt->base = devm_ioremap_nocache(&pdev->dev, res->start,
			resource_size(res));
	if (!wdt->base) {
		dev_err(&pdev->dev, "cannot remap I/O memory region\n");
		return -ENXIO;
	}

	/* disable watchdog and reboot on timeout */
	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	ctrl &= ~ADX_WDT_CONTROL_nRESET;
	writel(ctrl, wdt->base + ADX_WDT_CONTROL);

	platform_set_drvdata(pdev, wdt);
	adx_wdt_dev = pdev;

	ret = misc_register(&adx_wdt_miscdev);
	if (ret) {
		dev_err(&pdev->dev, "cannot register miscdev on minor %d "
				"(err=%d)\n", WATCHDOG_MINOR, ret);
		return ret;
	}

	return 0;
}

static int __devexit adx_wdt_remove(struct platform_device *pdev)
{
	struct adx_wdt *wdt = platform_get_drvdata(pdev);

	misc_deregister(&adx_wdt_miscdev);
	adx_wdt_stop(wdt);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static void adx_wdt_shutdown(struct platform_device *pdev)
{
	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	adx_wdt_stop(wdt);
}

#ifdef CONFIG_PM
static int adx_wdt_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct adx_wdt *wdt = platform_get_drvdata(pdev);

	wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0;
	adx_wdt_stop(wdt);

	return 0;
}

static int adx_wdt_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct adx_wdt *wdt = platform_get_drvdata(pdev);

	if (wdt->wake)
		adx_wdt_start(wdt);

	return 0;
}

static const struct dev_pm_ops adx_wdt_pm_ops = {
	.suspend = adx_wdt_suspend,
	.resume = adx_wdt_resume,
};

#  define ADX_WDT_PM_OPS	(&adx_wdt_pm_ops)
#else
#  define ADX_WDT_PM_OPS	NULL
#endif

static struct platform_driver adx_wdt_driver = {
	.probe = adx_wdt_probe,
	.remove = __devexit_p(adx_wdt_remove),
	.shutdown = adx_wdt_shutdown,
	.driver = {
		.name = WATCHDOG_NAME,
		.owner = THIS_MODULE,
		.pm = ADX_WDT_PM_OPS,
	},
};

static int __init adx_wdt_init(void)
{
	return platform_driver_register(&adx_wdt_driver);
}

static void __exit adx_wdt_exit(void)
{
	platform_driver_unregister(&adx_wdt_driver);
}

module_init(adx_wdt_init);
module_exit(adx_wdt_exit);

MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
38461c5c TR	1	/*
	2	* Copyright (C) 2008-2009 Avionic Design GmbH
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/fs.h>
	10	#include <linux/io.h>
	11	#include <linux/miscdevice.h>
	12	#include <linux/module.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/types.h>
	15	#include <linux/uaccess.h>
	16	#include <linux/watchdog.h>
	17
	18	#define WATCHDOG_NAME "adx-wdt"
	19
	20	/* register offsets */
	21	#define ADX_WDT_CONTROL 0x00
	22	#define ADX_WDT_CONTROL_ENABLE (1 << 0)
	23	#define ADX_WDT_CONTROL_nRESET (1 << 1)
	24	#define ADX_WDT_TIMEOUT 0x08
	25
	26	static struct platform_device *adx_wdt_dev;
	27	static unsigned long driver_open;
	28
	29	#define WDT_STATE_STOP 0
	30	#define WDT_STATE_START 1
	31
	32	struct adx_wdt {
	33	void __iomem *base;
	34	unsigned long timeout;
	35	unsigned int state;
	36	unsigned int wake;
	37	spinlock_t lock;
	38	};
	39
42747d71	40	static const struct watchdog_info adx_wdt_info = {
38461c5c TR	41	.identity = "Avionic Design Xanthos Watchdog",
	42	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	43	};
	44
	45	static void adx_wdt_start_locked(struct adx_wdt *wdt)
	46	{
	47	u32 ctrl;
	48
	49	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	50	ctrl \|= ADX_WDT_CONTROL_ENABLE;
	51	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	52	wdt->state = WDT_STATE_START;
	53	}
	54
	55	static void adx_wdt_start(struct adx_wdt *wdt)
	56	{
	57	unsigned long flags;
	58
	59	spin_lock_irqsave(&wdt->lock, flags);
	60	adx_wdt_start_locked(wdt);
	61	spin_unlock_irqrestore(&wdt->lock, flags);
	62	}
	63
	64	static void adx_wdt_stop_locked(struct adx_wdt *wdt)
	65	{
	66	u32 ctrl;
	67
	68	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	69	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	70	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	71	wdt->state = WDT_STATE_STOP;
	72	}
	73
	74	static void adx_wdt_stop(struct adx_wdt *wdt)
	75	{
	76	unsigned long flags;
	77
	78	spin_lock_irqsave(&wdt->lock, flags);
	79	adx_wdt_stop_locked(wdt);
	80	spin_unlock_irqrestore(&wdt->lock, flags);
	81	}
	82
	83	static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds)
	84	{
	85	unsigned long timeout = seconds * 1000;
	86	unsigned long flags;
	87	unsigned int state;
	88
	89	spin_lock_irqsave(&wdt->lock, flags);
	90	state = wdt->state;
	91	adx_wdt_stop_locked(wdt);
	92	writel(timeout, wdt->base + ADX_WDT_TIMEOUT);
	93
	94	if (state == WDT_STATE_START)
	95	adx_wdt_start_locked(wdt);
	96
	97	wdt->timeout = timeout;
	98	spin_unlock_irqrestore(&wdt->lock, flags);
	99	}
	100
	101	static void adx_wdt_get_timeout(struct adx_wdt wdt, unsigned long seconds)
	102	{
	103	*seconds = wdt->timeout / 1000;
	104	}
105
106	static void adx_wdt_keepalive(struct adx_wdt *wdt)
107	{
108	unsigned long flags;
109
110	spin_lock_irqsave(&wdt->lock, flags);
111	writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT);
112	spin_unlock_irqrestore(&wdt->lock, flags);
113	}
114
115	static int adx_wdt_open(struct inode inode, struct file file)
116	{
117	struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev);
118
119	if (test_and_set_bit(0, &driver_open))
120	return -EBUSY;
121
122	file->private_data = wdt;
123	adx_wdt_set_timeout(wdt, 30);
124	adx_wdt_start(wdt);
125
126	return nonseekable_open(inode, file);
127	}
128
129	static int adx_wdt_release(struct inode inode, struct file file)
130	{
131	struct adx_wdt *wdt = file->private_data;
132
133	adx_wdt_stop(wdt);
134	clear_bit(0, &driver_open);
135
136	return 0;
137	}
138
139	static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
140	{
141	struct adx_wdt *wdt = file->private_data;
142	void __user argp = (void __user )arg;
143	unsigned long __user *p = argp;
144	unsigned long seconds = 0;
145	unsigned int options;
146	long ret = -EINVAL;
147
148	switch (cmd) {
149	case WDIOC_GETSUPPORT:
150	if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info)))
151	return -EFAULT;
152	else
153	return 0;
154
155	case WDIOC_GETSTATUS:
156	case WDIOC_GETBOOTSTATUS:
157	return put_user(0, p);
158
159	case WDIOC_KEEPALIVE:
160	adx_wdt_keepalive(wdt);
161	return 0;
162
163	case WDIOC_SETTIMEOUT:
164	if (get_user(seconds, p))
165	return -EFAULT;
166
167	adx_wdt_set_timeout(wdt, seconds);
168
169	/* fallthrough */
170	case WDIOC_GETTIMEOUT:
171	adx_wdt_get_timeout(wdt, &seconds);
172	return put_user(seconds, p);
173
174	case WDIOC_SETOPTIONS:
175	if (copy_from_user(&options, argp, sizeof(options)))
176	return -EFAULT;
177
178	if (options & WDIOS_DISABLECARD) {
179	adx_wdt_stop(wdt);
180	ret = 0;
181	}
182
183	if (options & WDIOS_ENABLECARD) {
184	adx_wdt_start(wdt);
185	ret = 0;
186	}
187
188	return ret;
189
190	default:
191	break;
192	}
193
194	return -ENOTTY;
195	}
196
197	static ssize_t adx_wdt_write(struct file file, const char __user data,
198	size_t len, loff_t *ppos)
199	{
200	struct adx_wdt *wdt = file->private_data;
201
202	if (len)
203	adx_wdt_keepalive(wdt);
204
205	return len;
206	}
207
208	static const struct file_operations adx_wdt_fops = {
209	.owner = THIS_MODULE,
210	.llseek = no_llseek,
211	.open = adx_wdt_open,
212	.release = adx_wdt_release,
213	.unlocked_ioctl = adx_wdt_ioctl,
214	.write = adx_wdt_write,
215	};
216
217	static struct miscdevice adx_wdt_miscdev = {
218	.minor = WATCHDOG_MINOR,
219	.name = "watchdog",
220	.fops = &adx_wdt_fops,
221	};
222
223	static int __devinit adx_wdt_probe(struct platform_device *pdev)
224	{
225	struct resource *res;
226	struct adx_wdt *wdt;
227	int ret = 0;
228	u32 ctrl;
229
230	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
231	if (!wdt) {
232	dev_err(&pdev->dev, "cannot allocate WDT structure\n");
233	return -ENOMEM;
234	}
235
236	spin_lock_init(&wdt->lock);
237
238	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
239	if (!res) {
240	dev_err(&pdev->dev, "cannot obtain I/O memory region\n");
241	return -ENXIO;
242	}
243
244	res = devm_request_mem_region(&pdev->dev, res->start,
b782a563	245	resource_size(res), res->name);
38461c5c TR	246	if (!res) {
	247	dev_err(&pdev->dev, "cannot request I/O memory region\n");
	248	return -ENXIO;
	249	}
	250
	251	wdt->base = devm_ioremap_nocache(&pdev->dev, res->start,
b782a563	252	resource_size(res));
38461c5c TR	253	if (!wdt->base) {
	254	dev_err(&pdev->dev, "cannot remap I/O memory region\n");
	255	return -ENXIO;
	256	}
	257
	258	/* disable watchdog and reboot on timeout */
	259	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	260	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	261	ctrl &= ~ADX_WDT_CONTROL_nRESET;
	262	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	263
	264	platform_set_drvdata(pdev, wdt);
	265	adx_wdt_dev = pdev;
	266
	267	ret = misc_register(&adx_wdt_miscdev);
	268	if (ret) {
	269	dev_err(&pdev->dev, "cannot register miscdev on minor %d "
	270	"(err=%d)\n", WATCHDOG_MINOR, ret);
	271	return ret;
	272	}
	273
	274	return 0;
	275	}
	276
	277	static int __devexit adx_wdt_remove(struct platform_device *pdev)
	278	{
	279	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	280
	281	misc_deregister(&adx_wdt_miscdev);
	282	adx_wdt_stop(wdt);
	283	platform_set_drvdata(pdev, NULL);
	284
	285	return 0;
	286	}
	287
	288	static void adx_wdt_shutdown(struct platform_device *pdev)
	289	{
	290	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	291	adx_wdt_stop(wdt);
	292	}
	293
	294	#ifdef CONFIG_PM
	295	static int adx_wdt_suspend(struct device *dev)
	296	{
	297	struct platform_device *pdev = to_platform_device(dev);
	298	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	299
	300	wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0;
	301	adx_wdt_stop(wdt);
	302
	303	return 0;
	304	}
	305
	306	static int adx_wdt_resume(struct device *dev)
	307	{
	308	struct platform_device *pdev = to_platform_device(dev);
	309	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	310
	311	if (wdt->wake)
	312	adx_wdt_start(wdt);
	313
	314	return 0;
	315	}
	316
47145210	317	static const struct dev_pm_ops adx_wdt_pm_ops = {
38461c5c TR	318	.suspend = adx_wdt_suspend,
	319	.resume = adx_wdt_resume,
	320	};
	321
	322	# define ADX_WDT_PM_OPS (&adx_wdt_pm_ops)
	323	#else
	324	# define ADX_WDT_PM_OPS NULL
	325	#endif
	326
	327	static struct platform_driver adx_wdt_driver = {
	328	.probe = adx_wdt_probe,
	329	.remove = __devexit_p(adx_wdt_remove),
	330	.shutdown = adx_wdt_shutdown,
	331	.driver = {
	332	.name = WATCHDOG_NAME,
	333	.owner = THIS_MODULE,
	334	.pm = ADX_WDT_PM_OPS,
	335	},
	336	};
	337
	338	static int __init adx_wdt_init(void)
	339	{
	340	return platform_driver_register(&adx_wdt_driver);
	341	}
	342
	343	static void __exit adx_wdt_exit(void)
	344	{
	345	platform_driver_unregister(&adx_wdt_driver);
	346	}
	347
	348	module_init(adx_wdt_init);
	349	module_exit(adx_wdt_exit);
	350
	351	MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver");
	352	MODULE_LICENSE("GPL v2");
	353	MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
	354	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);