[net-next-2.6.git] / drivers / watchdog / twl4030_wdt.c

/*
 * Copyright (C) Nokia Corporation
 *
 * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/i2c/twl.h>

#define TWL4030_WATCHDOG_CFG_REG_OFFS	0x3

#define TWL4030_WDT_STATE_OPEN		0x1
#define TWL4030_WDT_STATE_ACTIVE	0x8

static struct platform_device *twl4030_wdt_dev;

struct twl4030_wdt {
	struct miscdevice	miscdev;
	int			timer_margin;
	unsigned long		state;
};

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int twl4030_wdt_write(unsigned char val)
{
	return twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val,
					TWL4030_WATCHDOG_CFG_REG_OFFS);
}

static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
{
	return twl4030_wdt_write(wdt->timer_margin + 1);
}

static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
{
	return twl4030_wdt_write(0);
}

static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
{
	if (timeout < 0 || timeout > 30) {
		dev_warn(wdt->miscdev.parent,
			"Timeout can only be in the range [0-30] seconds");
		return -EINVAL;
	}
	wdt->timer_margin = timeout;
	return twl4030_wdt_enable(wdt);
}

static ssize_t twl4030_wdt_write_fop(struct file *file,
		const char __user *data, size_t len, loff_t *ppos)
{
	struct twl4030_wdt *wdt = file->private_data;

	if (len)
		twl4030_wdt_enable(wdt);

	return len;
}

static long twl4030_wdt_ioctl(struct file *file,
		unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_margin;
	struct twl4030_wdt *wdt = file->private_data;

	static const struct watchdog_info twl4030_wd_ident = {
		.identity = "TWL4030 Watchdog",
		.options = WDIOF_SETTIMEOUT,
		.firmware_version = 0,
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &twl4030_wd_ident,
				sizeof(twl4030_wd_ident)) ? -EFAULT : 0;

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

	case WDIOC_KEEPALIVE:
		twl4030_wdt_enable(wdt);
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_margin, p))
			return -EFAULT;
		if (twl4030_wdt_set_timeout(wdt, new_margin))
			return -EINVAL;
		return put_user(wdt->timer_margin, p);

	case WDIOC_GETTIMEOUT:
		return put_user(wdt->timer_margin, p);

	default:
		return -ENOTTY;
	}

	return 0;
}

static int twl4030_wdt_open(struct inode *inode, struct file *file)
{
	struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);

	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &wdt->state))
		return -EBUSY;

	wdt->state |= TWL4030_WDT_STATE_ACTIVE;
	file->private_data = (void *) wdt;

	twl4030_wdt_enable(wdt);
	return nonseekable_open(inode, file);
}

static int twl4030_wdt_release(struct inode *inode, struct file *file)
{
	struct twl4030_wdt *wdt = file->private_data;
	if (nowayout) {
		dev_alert(wdt->miscdev.parent,
		       "Unexpected close, watchdog still running!\n");
		twl4030_wdt_enable(wdt);
	} else {
		if (twl4030_wdt_disable(wdt))
			return -EFAULT;
		wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
	}

	clear_bit(0, &wdt->state);
	return 0;
}

static const struct file_operations twl4030_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.open		= twl4030_wdt_open,
	.release	= twl4030_wdt_release,
	.unlocked_ioctl	= twl4030_wdt_ioctl,
	.write		= twl4030_wdt_write_fop,
};

static int __devinit twl4030_wdt_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct twl4030_wdt *wdt;

	wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;

	wdt->state		= 0;
	wdt->timer_margin	= 30;
	wdt->miscdev.parent	= &pdev->dev;
	wdt->miscdev.fops	= &twl4030_wdt_fops;
	wdt->miscdev.minor	= WATCHDOG_MINOR;
	wdt->miscdev.name	= "watchdog";

	platform_set_drvdata(pdev, wdt);

	twl4030_wdt_dev = pdev;

	ret = misc_register(&wdt->miscdev);
	if (ret) {
		dev_err(wdt->miscdev.parent,
			"Failed to register misc device\n");
		platform_set_drvdata(pdev, NULL);
		kfree(wdt);
		twl4030_wdt_dev = NULL;
		return ret;
	}
	return 0;
}

static int __devexit twl4030_wdt_remove(struct platform_device *pdev)
{
	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);

	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
		if (twl4030_wdt_disable(wdt))
			return -EFAULT;

	wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
	misc_deregister(&wdt->miscdev);

	platform_set_drvdata(pdev, NULL);
	kfree(wdt);
	twl4030_wdt_dev = NULL;

	return 0;
}

#ifdef CONFIG_PM
static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
		return twl4030_wdt_disable(wdt);

	return 0;
}

static int twl4030_wdt_resume(struct platform_device *pdev)
{
	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
		return twl4030_wdt_enable(wdt);

	return 0;
}
#else
#define twl4030_wdt_suspend        NULL
#define twl4030_wdt_resume         NULL
#endif

static struct platform_driver twl4030_wdt_driver = {
	.probe		= twl4030_wdt_probe,
	.remove		= __devexit_p(twl4030_wdt_remove),
	.suspend	= twl4030_wdt_suspend,
	.resume		= twl4030_wdt_resume,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "twl4030_wdt",
	},
};

static int __devinit twl4030_wdt_init(void)
{
	return platform_driver_register(&twl4030_wdt_driver);
}
module_init(twl4030_wdt_init);

static void __devexit twl4030_wdt_exit(void)
{
	platform_driver_unregister(&twl4030_wdt_driver);
}
module_exit(twl4030_wdt_exit);

MODULE_AUTHOR("Nokia Corporation");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:twl4030_wdt");
Commit	Line	Data
80e45b1e TK	1	/*
	2	* Copyright (C) Nokia Corporation
	3	*
	4	* Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/types.h>
5a0e3ad6	23	#include <linux/slab.h>
80e45b1e TK	24	#include <linux/kernel.h>
	25	#include <linux/fs.h>
	26	#include <linux/watchdog.h>
	27	#include <linux/platform_device.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/uaccess.h>
b07682b6	30	#include <linux/i2c/twl.h>
80e45b1e TK	31
	32	#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3
	33
	34	#define TWL4030_WDT_STATE_OPEN 0x1
	35	#define TWL4030_WDT_STATE_ACTIVE 0x8
	36
	37	static struct platform_device *twl4030_wdt_dev;
	38
	39	struct twl4030_wdt {
	40	struct miscdevice miscdev;
	41	int timer_margin;
	42	unsigned long state;
	43	};
	44
	45	static int nowayout = WATCHDOG_NOWAYOUT;
	46	module_param(nowayout, int, 0);
	47	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
	48	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	49
	50	static int twl4030_wdt_write(unsigned char val)
	51	{
fc7b92fc	52	return twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val,
80e45b1e TK	53	TWL4030_WATCHDOG_CFG_REG_OFFS);
	54	}
	55
	56	static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
	57	{
	58	return twl4030_wdt_write(wdt->timer_margin + 1);
	59	}
	60
	61	static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
	62	{
	63	return twl4030_wdt_write(0);
	64	}
	65
	66	static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
	67	{
	68	if (timeout < 0 \|\| timeout > 30) {
	69	dev_warn(wdt->miscdev.parent,
	70	"Timeout can only be in the range [0-30] seconds");
	71	return -EINVAL;
	72	}
	73	wdt->timer_margin = timeout;
	74	return twl4030_wdt_enable(wdt);
	75	}
	76
	77	static ssize_t twl4030_wdt_write_fop(struct file *file,
	78	const char __user data, size_t len, loff_t ppos)
	79	{
	80	struct twl4030_wdt *wdt = file->private_data;
	81
	82	if (len)
	83	twl4030_wdt_enable(wdt);
	84
	85	return len;
	86	}
	87
	88	static long twl4030_wdt_ioctl(struct file *file,
	89	unsigned int cmd, unsigned long arg)
	90	{
	91	void __user argp = (void __user )arg;
	92	int __user *p = argp;
	93	int new_margin;
	94	struct twl4030_wdt *wdt = file->private_data;
	95
	96	static const struct watchdog_info twl4030_wd_ident = {
	97	.identity = "TWL4030 Watchdog",
	98	.options = WDIOF_SETTIMEOUT,
	99	.firmware_version = 0,
	100	};
	101
	102	switch (cmd) {
	103	case WDIOC_GETSUPPORT:
	104	return copy_to_user(argp, &twl4030_wd_ident,
	105	sizeof(twl4030_wd_ident)) ? -EFAULT : 0;
	106
	107	case WDIOC_GETSTATUS:
	108	case WDIOC_GETBOOTSTATUS:
	109	return put_user(0, p);
	110
	111	case WDIOC_KEEPALIVE:
	112	twl4030_wdt_enable(wdt);
	113	break;
	114
	115	case WDIOC_SETTIMEOUT:
	116	if (get_user(new_margin, p))
117	return -EFAULT;
118	if (twl4030_wdt_set_timeout(wdt, new_margin))
119	return -EINVAL;
120	return put_user(wdt->timer_margin, p);
121
122	case WDIOC_GETTIMEOUT:
123	return put_user(wdt->timer_margin, p);
124
125	default:
126	return -ENOTTY;
127	}
128
129	return 0;
130	}
131
132	static int twl4030_wdt_open(struct inode inode, struct file file)
133	{
134	struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);
135
136	/* /dev/watchdog can only be opened once */
137	if (test_and_set_bit(0, &wdt->state))
138	return -EBUSY;
139
140	wdt->state \|= TWL4030_WDT_STATE_ACTIVE;
141	file->private_data = (void *) wdt;
142
143	twl4030_wdt_enable(wdt);
144	return nonseekable_open(inode, file);
145	}
146
147	static int twl4030_wdt_release(struct inode inode, struct file file)
148	{
149	struct twl4030_wdt *wdt = file->private_data;
150	if (nowayout) {
151	dev_alert(wdt->miscdev.parent,
152	"Unexpected close, watchdog still running!\n");
153	twl4030_wdt_enable(wdt);
154	} else {
155	if (twl4030_wdt_disable(wdt))
156	return -EFAULT;
157	wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
158	}
159
160	clear_bit(0, &wdt->state);
161	return 0;
162	}
163
164	static const struct file_operations twl4030_wdt_fops = {
165	.owner = THIS_MODULE,
166	.llseek = no_llseek,
167	.open = twl4030_wdt_open,
168	.release = twl4030_wdt_release,
169	.unlocked_ioctl = twl4030_wdt_ioctl,
170	.write = twl4030_wdt_write_fop,
171	};
172
173	static int __devinit twl4030_wdt_probe(struct platform_device *pdev)
174	{
175	int ret = 0;
176	struct twl4030_wdt *wdt;
177
178	wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
179	if (!wdt)
180	return -ENOMEM;
181
182	wdt->state = 0;
183	wdt->timer_margin = 30;
184	wdt->miscdev.parent = &pdev->dev;
185	wdt->miscdev.fops = &twl4030_wdt_fops;
186	wdt->miscdev.minor = WATCHDOG_MINOR;
187	wdt->miscdev.name = "watchdog";
188
189	platform_set_drvdata(pdev, wdt);
190
191	twl4030_wdt_dev = pdev;
192
193	ret = misc_register(&wdt->miscdev);
194	if (ret) {
195	dev_err(wdt->miscdev.parent,
196	"Failed to register misc device\n");
197	platform_set_drvdata(pdev, NULL);
198	kfree(wdt);
199	twl4030_wdt_dev = NULL;
200	return ret;
201	}
202	return 0;
203	}
204
205	static int __devexit twl4030_wdt_remove(struct platform_device *pdev)
206	{
207	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
208
209	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
210	if (twl4030_wdt_disable(wdt))
211	return -EFAULT;
212
213	wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
214	misc_deregister(&wdt->miscdev);
215
216	platform_set_drvdata(pdev, NULL);
217	kfree(wdt);
218	twl4030_wdt_dev = NULL;
219
220	return 0;
221	}
222
223	#ifdef CONFIG_PM
224	static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
225	{
226	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
227	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
228	return twl4030_wdt_disable(wdt);
229
230	return 0;
231	}
232
233	static int twl4030_wdt_resume(struct platform_device *pdev)
234	{
235	struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
236	if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
237	return twl4030_wdt_enable(wdt);
238
239	return 0;
240	}
241	#else
242	#define twl4030_wdt_suspend NULL
243	#define twl4030_wdt_resume NULL
244	#endif
245
246	static struct platform_driver twl4030_wdt_driver = {
247	.probe = twl4030_wdt_probe,
248	.remove = __devexit_p(twl4030_wdt_remove),
249	.suspend = twl4030_wdt_suspend,
250	.resume = twl4030_wdt_resume,
251	.driver = {
252	.owner = THIS_MODULE,
253	.name = "twl4030_wdt",
254	},
255	};
256
257	static int __devinit twl4030_wdt_init(void)
258	{
259	return platform_driver_register(&twl4030_wdt_driver);
260	}
261	module_init(twl4030_wdt_init);
262
263	static void __devexit twl4030_wdt_exit(void)
264	{
265	platform_driver_unregister(&twl4030_wdt_driver);
266	}
267	module_exit(twl4030_wdt_exit);
268
269	MODULE_AUTHOR("Nokia Corporation");
270	MODULE_LICENSE("GPL");
271	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
272	MODULE_ALIAS("platform:twl4030_wdt");
273