[net-next-2.6.git] / drivers / watchdog / stmp3xxx_wdt.c

/*
 * Watchdog driver for Freescale STMP37XX/STMP378X
 *
 * Author: Vitaly Wool <vital@embeddedalley.com>
 *
 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>

#include <mach/platform.h>
#include <mach/regs-rtc.h>

#define DEFAULT_HEARTBEAT	19
#define MAX_HEARTBEAT		(0x10000000 >> 6)

/* missing bitmask in headers */
#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER     0x80000000

#define WDT_IN_USE		0
#define WDT_OK_TO_CLOSE		1

#define WDOG_COUNTER_RATE	1000 /* 1 kHz clock */

static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
static unsigned long wdt_status;
static const int nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = DEFAULT_HEARTBEAT;
static unsigned long boot_status;

static void wdt_enable(u32 value)
{
	spin_lock(&stmp3xxx_wdt_io_lock);
	__raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
	stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
	stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
			REGS_RTC_BASE + HW_RTC_PERSISTENT1);
	spin_unlock(&stmp3xxx_wdt_io_lock);
}

static void wdt_disable(void)
{
	spin_lock(&stmp3xxx_wdt_io_lock);
	stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
			REGS_RTC_BASE + HW_RTC_PERSISTENT1);
	stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
	spin_unlock(&stmp3xxx_wdt_io_lock);
}

static void wdt_ping(void)
{
	wdt_enable(heartbeat * WDOG_COUNTER_RATE);
}

static int stmp3xxx_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
		return -EBUSY;

	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
	wdt_ping();

	return nonseekable_open(inode, file);
}

static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data,
	size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					set_bit(WDT_OK_TO_CLOSE, &wdt_status);
			}
		}
		wdt_ping();
	}

	return len;
}

static const struct watchdog_info ident = {
	.options	= WDIOF_CARDRESET |
			  WDIOF_MAGICCLOSE |
			  WDIOF_SETTIMEOUT |
			  WDIOF_KEEPALIVEPING,
	.identity	= "STMP3XXX Watchdog",
};

static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_heartbeat, opts;
	int ret = -ENOTTY;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
		break;

	case WDIOC_GETSTATUS:
		ret = put_user(0, p);
		break;

	case WDIOC_GETBOOTSTATUS:
		ret = put_user(boot_status, p);
		break;

	case WDIOC_SETOPTIONS:
		if (get_user(opts, p)) {
			ret = -EFAULT;
			break;
		}
		if (opts & WDIOS_DISABLECARD)
			wdt_disable();
		else if (opts & WDIOS_ENABLECARD)
			wdt_ping();
		else {
			pr_debug("%s: unknown option 0x%x\n", __func__, opts);
			ret = -EINVAL;
			break;
		}
		ret = 0;
		break;

	case WDIOC_KEEPALIVE:
		wdt_ping();
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_heartbeat, p)) {
			ret = -EFAULT;
			break;
		}
		if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) {
			ret = -EINVAL;
			break;
		}

		heartbeat = new_heartbeat;
		wdt_ping();
		/* Fall through */

	case WDIOC_GETTIMEOUT:
		ret = put_user(heartbeat, p);
		break;
	}
	return ret;
}

static int stmp3xxx_wdt_release(struct inode *inode, struct file *file)
{
	int ret = 0;

	if (!nowayout) {
		if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
			wdt_ping();
			pr_debug("%s: Device closed unexpectdly\n", __func__);
			ret = -EINVAL;
		} else {
			wdt_disable();
			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
		}
	}
	clear_bit(WDT_IN_USE, &wdt_status);

	return ret;
}

static const struct file_operations stmp3xxx_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = stmp3xxx_wdt_write,
	.unlocked_ioctl = stmp3xxx_wdt_ioctl,
	.open = stmp3xxx_wdt_open,
	.release = stmp3xxx_wdt_release,
};

static struct miscdevice stmp3xxx_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &stmp3xxx_wdt_fops,
};

static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
{
	int ret = 0;

	if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
		heartbeat = DEFAULT_HEARTBEAT;

	boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
			BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
	boot_status = !!boot_status;
	stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
			REGS_RTC_BASE + HW_RTC_PERSISTENT1);
	wdt_disable();		/* disable for now */

	ret = misc_register(&stmp3xxx_wdt_miscdev);
	if (ret < 0) {
		dev_err(&pdev->dev, "cannot register misc device\n");
		return ret;
	}

	printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n",
		heartbeat);

	return ret;
}

static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
{
	misc_deregister(&stmp3xxx_wdt_miscdev);
	return 0;
}

#ifdef CONFIG_PM
static int wdt_suspended;
static u32 wdt_saved_time;

static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
				pm_message_t state)
{
	if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
		BM_RTC_CTRL_WATCHDOGEN) {
		wdt_suspended = 1;
		wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
		wdt_disable();
	}
	return 0;
}

static int stmp3xxx_wdt_resume(struct platform_device *pdev)
{
	if (wdt_suspended) {
		wdt_enable(wdt_saved_time);
		wdt_suspended = 0;
	}
	return 0;
}
#else
#define stmp3xxx_wdt_suspend	NULL
#define stmp3xxx_wdt_resume	NULL
#endif

static struct platform_driver platform_wdt_driver = {
	.driver = {
		.name = "stmp3xxx_wdt",
	},
	.probe = stmp3xxx_wdt_probe,
	.remove = __devexit_p(stmp3xxx_wdt_remove),
	.suspend = stmp3xxx_wdt_suspend,
	.resume = stmp3xxx_wdt_resume,
};

static int __init stmp3xxx_wdt_init(void)
{
	return platform_driver_register(&platform_wdt_driver);
}

static void __exit stmp3xxx_wdt_exit(void)
{
	return platform_driver_unregister(&platform_wdt_driver);
}

module_init(stmp3xxx_wdt_init);
module_exit(stmp3xxx_wdt_exit);

MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
MODULE_LICENSE("GPL");

module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat,
		 "Watchdog heartbeat period in seconds from 1 to "
		 __MODULE_STRING(MAX_HEARTBEAT) ", default "
		 __MODULE_STRING(DEFAULT_HEARTBEAT));

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
accde168	1	/*
	2	* Watchdog driver for Freescale STMP37XX/STMP378X
	3	*
	4	* Author: Vitaly Wool <vital@embeddedalley.com>
	5	*
	6	* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
	7	* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
	8	*/
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/fs.h>
	12	#include <linux/miscdevice.h>
	13	#include <linux/watchdog.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/spinlock.h>
	16	#include <linux/uaccess.h>
	17
	18	#include <mach/platform.h>
	19	#include <mach/regs-rtc.h>
	20
	21	#define DEFAULT_HEARTBEAT 19
	22	#define MAX_HEARTBEAT (0x10000000 >> 6)
	23
	24	/* missing bitmask in headers */
	25	#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
	26
	27	#define WDT_IN_USE 0
	28	#define WDT_OK_TO_CLOSE 1
	29
	30	#define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */
	31
	32	static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
	33	static unsigned long wdt_status;
	34	static const int nowayout = WATCHDOG_NOWAYOUT;
	35	static int heartbeat = DEFAULT_HEARTBEAT;
	36	static unsigned long boot_status;
	37
	38	static void wdt_enable(u32 value)
	39	{
	40	spin_lock(&stmp3xxx_wdt_io_lock);
	41	__raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
	42	stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
	43	stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
	44	REGS_RTC_BASE + HW_RTC_PERSISTENT1);
	45	spin_unlock(&stmp3xxx_wdt_io_lock);
	46	}
	47
	48	static void wdt_disable(void)
	49	{
	50	spin_lock(&stmp3xxx_wdt_io_lock);
	51	stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
	52	REGS_RTC_BASE + HW_RTC_PERSISTENT1);
	53	stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
	54	spin_unlock(&stmp3xxx_wdt_io_lock);
	55	}
	56
	57	static void wdt_ping(void)
	58	{
	59	wdt_enable(heartbeat * WDOG_COUNTER_RATE);
	60	}
	61
	62	static int stmp3xxx_wdt_open(struct inode inode, struct file file)
	63	{
	64	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
65	return -EBUSY;
66
67	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
68	wdt_ping();
69
70	return nonseekable_open(inode, file);
71	}
72
73	static ssize_t stmp3xxx_wdt_write(struct file file, const char __user data,
74	size_t len, loff_t *ppos)
75	{
76	if (len) {
77	if (!nowayout) {
78	size_t i;
79
80	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
81
82	for (i = 0; i != len; i++) {
83	char c;
84
85	if (get_user(c, data + i))
86	return -EFAULT;
87	if (c == 'V')
88	set_bit(WDT_OK_TO_CLOSE, &wdt_status);
89	}
90	}
91	wdt_ping();
92	}
93
94	return len;
95	}
96
42747d71	97	static const struct watchdog_info ident = {
accde168	98	.options = WDIOF_CARDRESET \|
	99	WDIOF_MAGICCLOSE \|
	100	WDIOF_SETTIMEOUT \|
	101	WDIOF_KEEPALIVEPING,
	102	.identity = "STMP3XXX Watchdog",
	103	};
	104
	105	static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
	106	unsigned long arg)
	107	{
	108	void __user argp = (void __user )arg;
	109	int __user *p = argp;
	110	int new_heartbeat, opts;
	111	int ret = -ENOTTY;
	112
	113	switch (cmd) {
	114	case WDIOC_GETSUPPORT:
	115	ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	116	break;
	117
	118	case WDIOC_GETSTATUS:
	119	ret = put_user(0, p);
	120	break;
	121
	122	case WDIOC_GETBOOTSTATUS:
	123	ret = put_user(boot_status, p);
	124	break;
	125
	126	case WDIOC_SETOPTIONS:
	127	if (get_user(opts, p)) {
	128	ret = -EFAULT;
	129	break;
	130	}
	131	if (opts & WDIOS_DISABLECARD)
	132	wdt_disable();
	133	else if (opts & WDIOS_ENABLECARD)
	134	wdt_ping();
	135	else {
	136	pr_debug("%s: unknown option 0x%x\n", __func__, opts);
	137	ret = -EINVAL;
	138	break;
	139	}
	140	ret = 0;
	141	break;
	142
	143	case WDIOC_KEEPALIVE:
	144	wdt_ping();
	145	ret = 0;
	146	break;
	147
	148	case WDIOC_SETTIMEOUT:
	149	if (get_user(new_heartbeat, p)) {
	150	ret = -EFAULT;
	151	break;
	152	}
	153	if (new_heartbeat <= 0 \|\| new_heartbeat > MAX_HEARTBEAT) {
	154	ret = -EINVAL;
	155	break;
	156	}
	157
	158	heartbeat = new_heartbeat;
	159	wdt_ping();
	160	/* Fall through */
	161
162	case WDIOC_GETTIMEOUT:
163	ret = put_user(heartbeat, p);
164	break;
165	}
166	return ret;
167	}
168
169	static int stmp3xxx_wdt_release(struct inode inode, struct file file)
170	{
171	int ret = 0;
172
173	if (!nowayout) {
174	if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
175	wdt_ping();
176	pr_debug("%s: Device closed unexpectdly\n", __func__);
177	ret = -EINVAL;
178	} else {
179	wdt_disable();
180	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
181	}
182	}
183	clear_bit(WDT_IN_USE, &wdt_status);
184
185	return ret;
186	}
187
188	static const struct file_operations stmp3xxx_wdt_fops = {
189	.owner = THIS_MODULE,
190	.llseek = no_llseek,
191	.write = stmp3xxx_wdt_write,
192	.unlocked_ioctl = stmp3xxx_wdt_ioctl,
193	.open = stmp3xxx_wdt_open,
194	.release = stmp3xxx_wdt_release,
195	};
196
197	static struct miscdevice stmp3xxx_wdt_miscdev = {
198	.minor = WATCHDOG_MINOR,
199	.name = "watchdog",
200	.fops = &stmp3xxx_wdt_fops,
201	};
202
203	static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
204	{
205	int ret = 0;
206
207	if (heartbeat < 1 \|\| heartbeat > MAX_HEARTBEAT)
208	heartbeat = DEFAULT_HEARTBEAT;
209
210	boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
211	BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
212	boot_status = !!boot_status;
213	stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
214	REGS_RTC_BASE + HW_RTC_PERSISTENT1);
215	wdt_disable(); /* disable for now */
216
217	ret = misc_register(&stmp3xxx_wdt_miscdev);
218	if (ret < 0) {
219	dev_err(&pdev->dev, "cannot register misc device\n");
220	return ret;
221	}
222
223	printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n",
224	heartbeat);
225
226	return ret;
227	}
228
229	static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
230	{
231	misc_deregister(&stmp3xxx_wdt_miscdev);
232	return 0;
233	}
234
235	#ifdef CONFIG_PM
236	static int wdt_suspended;
237	static u32 wdt_saved_time;
238
239	static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
240	pm_message_t state)
241	{
242	if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
243	BM_RTC_CTRL_WATCHDOGEN) {
244	wdt_suspended = 1;
245	wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
246	wdt_disable();
247	}
248	return 0;
249	}
250
251	static int stmp3xxx_wdt_resume(struct platform_device *pdev)
252	{
253	if (wdt_suspended) {
254	wdt_enable(wdt_saved_time);
255	wdt_suspended = 0;
256	}
257	return 0;
258	}
259	#else
260	#define stmp3xxx_wdt_suspend NULL
261	#define stmp3xxx_wdt_resume NULL
262	#endif
263
264	static struct platform_driver platform_wdt_driver = {
265	.driver = {
266	.name = "stmp3xxx_wdt",
267	},
268	.probe = stmp3xxx_wdt_probe,
269	.remove = __devexit_p(stmp3xxx_wdt_remove),
270	.suspend = stmp3xxx_wdt_suspend,
271	.resume = stmp3xxx_wdt_resume,
272	};
273
274	static int __init stmp3xxx_wdt_init(void)
275	{
276	return platform_driver_register(&platform_wdt_driver);
277	}
278
279	static void __exit stmp3xxx_wdt_exit(void)
280	{
281	return platform_driver_unregister(&platform_wdt_driver);
282	}
283
284	module_init(stmp3xxx_wdt_init);
285	module_exit(stmp3xxx_wdt_exit);
286
287	MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
288	MODULE_LICENSE("GPL");
289
290	module_param(heartbeat, int, 0);
291	MODULE_PARM_DESC(heartbeat,
292	"Watchdog heartbeat period in seconds from 1 to "
293	__MODULE_STRING(MAX_HEARTBEAT) ", default "
294	__MODULE_STRING(DEFAULT_HEARTBEAT));
295
296	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);