[mirror_ubuntu-bionic-kernel.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/gfp.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>
5a0e3ad6	10	#include <linux/gfp.h>
38461c5c TR	11	#include <linux/io.h>
	12	#include <linux/miscdevice.h>
	13	#include <linux/module.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/types.h>
	16	#include <linux/uaccess.h>
	17	#include <linux/watchdog.h>
	18
	19	#define WATCHDOG_NAME "adx-wdt"
	20
	21	/* register offsets */
	22	#define ADX_WDT_CONTROL 0x00
	23	#define ADX_WDT_CONTROL_ENABLE (1 << 0)
	24	#define ADX_WDT_CONTROL_nRESET (1 << 1)
	25	#define ADX_WDT_TIMEOUT 0x08
	26
	27	static struct platform_device *adx_wdt_dev;
	28	static unsigned long driver_open;
	29
	30	#define WDT_STATE_STOP 0
	31	#define WDT_STATE_START 1
	32
	33	struct adx_wdt {
	34	void __iomem *base;
	35	unsigned long timeout;
	36	unsigned int state;
	37	unsigned int wake;
	38	spinlock_t lock;
	39	};
	40
42747d71	41	static const struct watchdog_info adx_wdt_info = {
38461c5c TR	42	.identity = "Avionic Design Xanthos Watchdog",
	43	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	44	};
	45
	46	static void adx_wdt_start_locked(struct adx_wdt *wdt)
	47	{
	48	u32 ctrl;
	49
	50	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	51	ctrl \|= ADX_WDT_CONTROL_ENABLE;
	52	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	53	wdt->state = WDT_STATE_START;
	54	}
	55
	56	static void adx_wdt_start(struct adx_wdt *wdt)
	57	{
	58	unsigned long flags;
	59
	60	spin_lock_irqsave(&wdt->lock, flags);
	61	adx_wdt_start_locked(wdt);
	62	spin_unlock_irqrestore(&wdt->lock, flags);
	63	}
	64
	65	static void adx_wdt_stop_locked(struct adx_wdt *wdt)
	66	{
	67	u32 ctrl;
	68
	69	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	70	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	71	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	72	wdt->state = WDT_STATE_STOP;
	73	}
	74
	75	static void adx_wdt_stop(struct adx_wdt *wdt)
	76	{
	77	unsigned long flags;
	78
	79	spin_lock_irqsave(&wdt->lock, flags);
	80	adx_wdt_stop_locked(wdt);
	81	spin_unlock_irqrestore(&wdt->lock, flags);
	82	}
	83
	84	static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds)
	85	{
	86	unsigned long timeout = seconds * 1000;
	87	unsigned long flags;
	88	unsigned int state;
	89
	90	spin_lock_irqsave(&wdt->lock, flags);
	91	state = wdt->state;
	92	adx_wdt_stop_locked(wdt);
	93	writel(timeout, wdt->base + ADX_WDT_TIMEOUT);
	94
	95	if (state == WDT_STATE_START)
	96	adx_wdt_start_locked(wdt);
	97
	98	wdt->timeout = timeout;
	99	spin_unlock_irqrestore(&wdt->lock, flags);
	100	}
	101
	102	static void adx_wdt_get_timeout(struct adx_wdt wdt, unsigned long seconds)
	103	{
	104	*seconds = wdt->timeout / 1000;
	105	}
106
107	static void adx_wdt_keepalive(struct adx_wdt *wdt)
108	{
109	unsigned long flags;
110
111	spin_lock_irqsave(&wdt->lock, flags);
112	writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT);
113	spin_unlock_irqrestore(&wdt->lock, flags);
114	}
115
116	static int adx_wdt_open(struct inode inode, struct file file)
117	{
118	struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev);
119
120	if (test_and_set_bit(0, &driver_open))
121	return -EBUSY;
122
123	file->private_data = wdt;
124	adx_wdt_set_timeout(wdt, 30);
125	adx_wdt_start(wdt);
126
127	return nonseekable_open(inode, file);
128	}
129
130	static int adx_wdt_release(struct inode inode, struct file file)
131	{
132	struct adx_wdt *wdt = file->private_data;
133
134	adx_wdt_stop(wdt);
135	clear_bit(0, &driver_open);
136
137	return 0;
138	}
139
140	static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
141	{
142	struct adx_wdt *wdt = file->private_data;
143	void __user argp = (void __user )arg;
144	unsigned long __user *p = argp;
145	unsigned long seconds = 0;
146	unsigned int options;
147	long ret = -EINVAL;
148
149	switch (cmd) {
150	case WDIOC_GETSUPPORT:
151	if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info)))
152	return -EFAULT;
153	else
154	return 0;
155
156	case WDIOC_GETSTATUS:
157	case WDIOC_GETBOOTSTATUS:
158	return put_user(0, p);
159
160	case WDIOC_KEEPALIVE:
161	adx_wdt_keepalive(wdt);
162	return 0;
163
164	case WDIOC_SETTIMEOUT:
165	if (get_user(seconds, p))
166	return -EFAULT;
167
168	adx_wdt_set_timeout(wdt, seconds);
169
170	/* fallthrough */
171	case WDIOC_GETTIMEOUT:
172	adx_wdt_get_timeout(wdt, &seconds);
173	return put_user(seconds, p);
174
175	case WDIOC_SETOPTIONS:
176	if (copy_from_user(&options, argp, sizeof(options)))
177	return -EFAULT;
178
179	if (options & WDIOS_DISABLECARD) {
180	adx_wdt_stop(wdt);
181	ret = 0;
182	}
183
184	if (options & WDIOS_ENABLECARD) {
185	adx_wdt_start(wdt);
186	ret = 0;
187	}
188
189	return ret;
190
191	default:
192	break;
193	}
194
195	return -ENOTTY;
196	}
197
198	static ssize_t adx_wdt_write(struct file file, const char __user data,
199	size_t len, loff_t *ppos)
200	{
201	struct adx_wdt *wdt = file->private_data;
202
203	if (len)
204	adx_wdt_keepalive(wdt);
205
206	return len;
207	}
208
209	static const struct file_operations adx_wdt_fops = {
210	.owner = THIS_MODULE,
211	.llseek = no_llseek,
212	.open = adx_wdt_open,
213	.release = adx_wdt_release,
214	.unlocked_ioctl = adx_wdt_ioctl,
215	.write = adx_wdt_write,
216	};
217
218	static struct miscdevice adx_wdt_miscdev = {
219	.minor = WATCHDOG_MINOR,
220	.name = "watchdog",
221	.fops = &adx_wdt_fops,
222	};
223
224	static int __devinit adx_wdt_probe(struct platform_device *pdev)
225	{
226	struct resource *res;
227	struct adx_wdt *wdt;
228	int ret = 0;
229	u32 ctrl;
230
231	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
232	if (!wdt) {
233	dev_err(&pdev->dev, "cannot allocate WDT structure\n");
234	return -ENOMEM;
235	}
236
237	spin_lock_init(&wdt->lock);
238
239	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
240	if (!res) {
241	dev_err(&pdev->dev, "cannot obtain I/O memory region\n");
242	return -ENXIO;
243	}
244
245	res = devm_request_mem_region(&pdev->dev, res->start,
b782a563	246	resource_size(res), res->name);
38461c5c TR	247	if (!res) {
	248	dev_err(&pdev->dev, "cannot request I/O memory region\n");
	249	return -ENXIO;
	250	}
	251
	252	wdt->base = devm_ioremap_nocache(&pdev->dev, res->start,
b782a563	253	resource_size(res));
38461c5c TR	254	if (!wdt->base) {
	255	dev_err(&pdev->dev, "cannot remap I/O memory region\n");
	256	return -ENXIO;
	257	}
	258
	259	/* disable watchdog and reboot on timeout */
	260	ctrl = readl(wdt->base + ADX_WDT_CONTROL);
	261	ctrl &= ~ADX_WDT_CONTROL_ENABLE;
	262	ctrl &= ~ADX_WDT_CONTROL_nRESET;
	263	writel(ctrl, wdt->base + ADX_WDT_CONTROL);
	264
	265	platform_set_drvdata(pdev, wdt);
	266	adx_wdt_dev = pdev;
	267
	268	ret = misc_register(&adx_wdt_miscdev);
	269	if (ret) {
	270	dev_err(&pdev->dev, "cannot register miscdev on minor %d "
	271	"(err=%d)\n", WATCHDOG_MINOR, ret);
	272	return ret;
	273	}
	274
	275	return 0;
	276	}
	277
	278	static int __devexit adx_wdt_remove(struct platform_device *pdev)
	279	{
	280	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	281
	282	misc_deregister(&adx_wdt_miscdev);
	283	adx_wdt_stop(wdt);
	284	platform_set_drvdata(pdev, NULL);
	285
	286	return 0;
	287	}
	288
	289	static void adx_wdt_shutdown(struct platform_device *pdev)
	290	{
	291	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	292	adx_wdt_stop(wdt);
	293	}
	294
	295	#ifdef CONFIG_PM
	296	static int adx_wdt_suspend(struct device *dev)
	297	{
	298	struct platform_device *pdev = to_platform_device(dev);
	299	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	300
	301	wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0;
	302	adx_wdt_stop(wdt);
	303
	304	return 0;
	305	}
	306
	307	static int adx_wdt_resume(struct device *dev)
	308	{
	309	struct platform_device *pdev = to_platform_device(dev);
	310	struct adx_wdt *wdt = platform_get_drvdata(pdev);
	311
	312	if (wdt->wake)
	313	adx_wdt_start(wdt);
	314
	315	return 0;
	316	}
	317
47145210	318	static const struct dev_pm_ops adx_wdt_pm_ops = {
38461c5c TR	319	.suspend = adx_wdt_suspend,
	320	.resume = adx_wdt_resume,
	321	};
	322
	323	# define ADX_WDT_PM_OPS (&adx_wdt_pm_ops)
	324	#else
	325	# define ADX_WDT_PM_OPS NULL
	326	#endif
	327
	328	static struct platform_driver adx_wdt_driver = {
	329	.probe = adx_wdt_probe,
	330	.remove = __devexit_p(adx_wdt_remove),
	331	.shutdown = adx_wdt_shutdown,
	332	.driver = {
	333	.name = WATCHDOG_NAME,
	334	.owner = THIS_MODULE,
	335	.pm = ADX_WDT_PM_OPS,
	336	},
	337	};
	338
	339	static int __init adx_wdt_init(void)
	340	{
	341	return platform_driver_register(&adx_wdt_driver);
	342	}
	343
	344	static void __exit adx_wdt_exit(void)
	345	{
	346	platform_driver_unregister(&adx_wdt_driver);
	347	}
	348
	349	module_init(adx_wdt_init);
	350	module_exit(adx_wdt_exit);
	351
	352	MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver");
	353	MODULE_LICENSE("GPL v2");
	354	MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
	355	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);