[deliverable/linux.git] / drivers / char / watchdog / cpu5wdt.c

/*
 * sma cpu5 watchdog driver
 *
 * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
 *
 * 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/init.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#include <linux/watchdog.h>

/* adjustable parameters */

static int verbose = 0;
static int port = 0x91;
static int ticks = 10000;

#define PFX			"cpu5wdt: "

#define CPU5WDT_EXTENT          0x0A

#define CPU5WDT_STATUS_REG      0x00
#define CPU5WDT_TIME_A_REG      0x02
#define CPU5WDT_TIME_B_REG      0x03
#define CPU5WDT_MODE_REG        0x04
#define CPU5WDT_TRIGGER_REG     0x07
#define CPU5WDT_ENABLE_REG      0x08
#define CPU5WDT_RESET_REG       0x09

#define CPU5WDT_INTERVAL	(HZ/10+1)

/* some device data */

static struct {
	struct semaphore stop;
	volatile int running;
	struct timer_list timer;
	volatile int queue;
	int default_ticks;
	unsigned long inuse;
} cpu5wdt_device;

/* generic helper functions */

static void cpu5wdt_trigger(unsigned long unused)
{
	if ( verbose > 2 )
		printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);

	if( cpu5wdt_device.running )
		ticks--;

	/* keep watchdog alive */
	outb(1, port + CPU5WDT_TRIGGER_REG);

	/* requeue?? */
	if( cpu5wdt_device.queue && ticks ) {
		cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
		add_timer(&cpu5wdt_device.timer);
	}
	else {
		/* ticks doesn't matter anyway */
		up(&cpu5wdt_device.stop);
	}

}

static void cpu5wdt_reset(void)
{
	ticks = cpu5wdt_device.default_ticks;

	if ( verbose )
		printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);

}

static void cpu5wdt_start(void)
{
	if ( !cpu5wdt_device.queue ) {
		cpu5wdt_device.queue = 1;
		outb(0, port + CPU5WDT_TIME_A_REG);
		outb(0, port + CPU5WDT_TIME_B_REG);
		outb(1, port + CPU5WDT_MODE_REG);
		outb(0, port + CPU5WDT_RESET_REG);
		outb(0, port + CPU5WDT_ENABLE_REG);
		cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
		add_timer(&cpu5wdt_device.timer);
	}
	/* if process dies, counter is not decremented */
	cpu5wdt_device.running++;
}

static int cpu5wdt_stop(void)
{
	if ( cpu5wdt_device.running )
		cpu5wdt_device.running = 0;

	ticks = cpu5wdt_device.default_ticks;

	if ( verbose )
		printk(KERN_CRIT PFX "stop not possible\n");

	return -EIO;
}

/* filesystem operations */

static int cpu5wdt_open(struct inode *inode, struct file *file)
{
	if ( test_and_set_bit(0, &cpu5wdt_device.inuse) )
		return -EBUSY;

	return nonseekable_open(inode, file);
}

static int cpu5wdt_release(struct inode *inode, struct file *file)
{
	clear_bit(0, &cpu5wdt_device.inuse);
	return 0;
}

static int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	unsigned int value;
	static struct watchdog_info ident =
	{
		.options = WDIOF_CARDRESET,
		.identity = "CPU5 WDT",
	};

	switch(cmd) {
		case WDIOC_KEEPALIVE:
			cpu5wdt_reset();
			break;
		case WDIOC_GETSTATUS:
			value = inb(port + CPU5WDT_STATUS_REG);
			value = (value >> 2) & 1;
			if ( copy_to_user(argp, &value, sizeof(int)) )
				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:
					cpu5wdt_start();
					break;
				case WDIOS_DISABLECARD:
					return cpu5wdt_stop();
				default:
					return -EINVAL;
			}
			break;
		default:
    			return -ENOIOCTLCMD;
	}
	return 0;
}

static ssize_t cpu5wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	if ( !count )
		return -EIO;

	cpu5wdt_reset();

	return count;
}

static struct file_operations cpu5wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.ioctl		= cpu5wdt_ioctl,
	.open		= cpu5wdt_open,
	.write		= cpu5wdt_write,
	.release	= cpu5wdt_release,
};

static struct miscdevice cpu5wdt_misc = {
	.minor	= WATCHDOG_MINOR,
	.name	= "watchdog",
	.fops	= &cpu5wdt_fops,
};

/* init/exit function */

static int __devinit cpu5wdt_init(void)
{
	unsigned int val;
	int err;

	if ( verbose )
		printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);

	if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {
		printk(KERN_ERR PFX "misc_register failed\n");
		goto no_misc;
	}

	if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {
		printk(KERN_ERR PFX "request_region failed\n");
		err = -EBUSY;
		goto no_port;
	}

	/* watchdog reboot? */
	val = inb(port + CPU5WDT_STATUS_REG);
	val = (val >> 2) & 1;
	if ( !val )
		printk(KERN_INFO PFX "sorry, was my fault\n");

	init_MUTEX_LOCKED(&cpu5wdt_device.stop);
	cpu5wdt_device.queue = 0;

	clear_bit(0, &cpu5wdt_device.inuse);

	init_timer(&cpu5wdt_device.timer);
	cpu5wdt_device.timer.function = cpu5wdt_trigger;
	cpu5wdt_device.timer.data = 0;

	cpu5wdt_device.default_ticks = ticks;

	printk(KERN_INFO PFX "init success\n");

	return 0;

no_port:
	misc_deregister(&cpu5wdt_misc);
no_misc:
	return err;
}

static int __devinit cpu5wdt_init_module(void)
{
	return cpu5wdt_init();
}

static void __devexit cpu5wdt_exit(void)
{
	if ( cpu5wdt_device.queue ) {
		cpu5wdt_device.queue = 0;
		down(&cpu5wdt_device.stop);
	}

	misc_deregister(&cpu5wdt_misc);

	release_region(port, CPU5WDT_EXTENT);

}

static void __devexit cpu5wdt_exit_module(void)
{
	cpu5wdt_exit();
}

/* module entry points */

module_init(cpu5wdt_init_module);
module_exit(cpu5wdt_exit_module);

MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
MODULE_DESCRIPTION("sma cpu5 watchdog driver");
MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(port, int, 0);
MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");

module_param(verbose, int, 0);
MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");

module_param(ticks, int, 0);
MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* sma cpu5 watchdog driver
	3	*
	4	* Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
	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., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*
	20	*/
	21
	22	#include <linux/module.h>
	23	#include <linux/moduleparam.h>
	24	#include <linux/types.h>
	25	#include <linux/errno.h>
	26	#include <linux/miscdevice.h>
	27	#include <linux/fs.h>
	28	#include <linux/init.h>
	29	#include <linux/ioport.h>
	30	#include <linux/timer.h>
	31	#include <asm/io.h>
	32	#include <asm/uaccess.h>
	33
	34	#include <linux/watchdog.h>
	35
	36	/* adjustable parameters */
	37
	38	static int verbose = 0;
	39	static int port = 0x91;
	40	static int ticks = 10000;
	41
	42	#define PFX "cpu5wdt: "
	43
	44	#define CPU5WDT_EXTENT 0x0A
	45
	46	#define CPU5WDT_STATUS_REG 0x00
	47	#define CPU5WDT_TIME_A_REG 0x02
	48	#define CPU5WDT_TIME_B_REG 0x03
	49	#define CPU5WDT_MODE_REG 0x04
	50	#define CPU5WDT_TRIGGER_REG 0x07
	51	#define CPU5WDT_ENABLE_REG 0x08
	52	#define CPU5WDT_RESET_REG 0x09
	53
	54	#define CPU5WDT_INTERVAL (HZ/10+1)
	55
	56	/* some device data */
	57
	58	static struct {
	59	struct semaphore stop;
	60	volatile int running;
	61	struct timer_list timer;
	62	volatile int queue;
	63	int default_ticks;
	64	unsigned long inuse;
65	} cpu5wdt_device;
66
67	/* generic helper functions */
68
69	static void cpu5wdt_trigger(unsigned long unused)
70	{
71	if ( verbose > 2 )
72	printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);
73
74	if( cpu5wdt_device.running )
75	ticks--;
76
77	/* keep watchdog alive */
78	outb(1, port + CPU5WDT_TRIGGER_REG);
79
80	/* requeue?? */
81	if( cpu5wdt_device.queue && ticks ) {
82	cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
83	add_timer(&cpu5wdt_device.timer);
84	}
85	else {
86	/* ticks doesn't matter anyway */
87	up(&cpu5wdt_device.stop);
88	}
89
90	}
91
92	static void cpu5wdt_reset(void)
93	{
94	ticks = cpu5wdt_device.default_ticks;
95
96	if ( verbose )
97	printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);
98
99	}
100
101	static void cpu5wdt_start(void)
102	{
103	if ( !cpu5wdt_device.queue ) {
104	cpu5wdt_device.queue = 1;
105	outb(0, port + CPU5WDT_TIME_A_REG);
106	outb(0, port + CPU5WDT_TIME_B_REG);
107	outb(1, port + CPU5WDT_MODE_REG);
108	outb(0, port + CPU5WDT_RESET_REG);
109	outb(0, port + CPU5WDT_ENABLE_REG);
110	cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
111	add_timer(&cpu5wdt_device.timer);
112	}
113	/* if process dies, counter is not decremented */
114	cpu5wdt_device.running++;
115	}
116
117	static int cpu5wdt_stop(void)
118	{
119	if ( cpu5wdt_device.running )
120	cpu5wdt_device.running = 0;
121
122	ticks = cpu5wdt_device.default_ticks;
123
124	if ( verbose )
125	printk(KERN_CRIT PFX "stop not possible\n");
126
127	return -EIO;
128	}
129
130	/* filesystem operations */
131
132	static int cpu5wdt_open(struct inode inode, struct file file)
133	{
134	if ( test_and_set_bit(0, &cpu5wdt_device.inuse) )
135	return -EBUSY;
136
137	return nonseekable_open(inode, file);
138	}
139
140	static int cpu5wdt_release(struct inode inode, struct file file)
141	{
142	clear_bit(0, &cpu5wdt_device.inuse);
143	return 0;
144	}
145
146	static int cpu5wdt_ioctl(struct inode inode, struct file file, unsigned int cmd, unsigned long arg)
147	{
148	void __user argp = (void __user )arg;
149	unsigned int value;
150	static struct watchdog_info ident =
151	{
152	.options = WDIOF_CARDRESET,
153	.identity = "CPU5 WDT",
154	};
155
156	switch(cmd) {
157	case WDIOC_KEEPALIVE:
158	cpu5wdt_reset();
159	break;
160	case WDIOC_GETSTATUS:
161	value = inb(port + CPU5WDT_STATUS_REG);
162	value = (value >> 2) & 1;
163	if ( copy_to_user(argp, &value, sizeof(int)) )
164	return -EFAULT;
165	break;
166	case WDIOC_GETSUPPORT:
167	if ( copy_to_user(argp, &ident, sizeof(ident)) )
168	return -EFAULT;
169	break;
170	case WDIOC_SETOPTIONS:
171	if ( copy_from_user(&value, argp, sizeof(int)) )
172	return -EFAULT;
173	switch(value) {
174	case WDIOS_ENABLECARD:
175	cpu5wdt_start();
176	break;
177	case WDIOS_DISABLECARD:
178	return cpu5wdt_stop();
179	default:
180	return -EINVAL;
181	}
182	break;
183	default:
184	return -ENOIOCTLCMD;
185	}
186	return 0;
187	}
188
189	static ssize_t cpu5wdt_write(struct file file, const char __user buf, size_t count, loff_t *ppos)
190	{
191	if ( !count )
192	return -EIO;
193
194	cpu5wdt_reset();
195
196	return count;
197	}
198
199	static struct file_operations cpu5wdt_fops = {
200	.owner = THIS_MODULE,
201	.llseek = no_llseek,
202	.ioctl = cpu5wdt_ioctl,
203	.open = cpu5wdt_open,
204	.write = cpu5wdt_write,
205	.release = cpu5wdt_release,
206	};
207
208	static struct miscdevice cpu5wdt_misc = {
209	.minor = WATCHDOG_MINOR,
210	.name = "watchdog",
211	.fops = &cpu5wdt_fops,
212	};
213
214	/* init/exit function */
215
216	static int __devinit cpu5wdt_init(void)
217	{
218	unsigned int val;
219	int err;
220
221	if ( verbose )
222	printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);
223
224	if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {
225	printk(KERN_ERR PFX "misc_register failed\n");
226	goto no_misc;
227	}
228
229	if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {
230	printk(KERN_ERR PFX "request_region failed\n");
231	err = -EBUSY;
232	goto no_port;
233	}
234
235	/* watchdog reboot? */
236	val = inb(port + CPU5WDT_STATUS_REG);
237	val = (val >> 2) & 1;
238	if ( !val )
239	printk(KERN_INFO PFX "sorry, was my fault\n");
240
241	init_MUTEX_LOCKED(&cpu5wdt_device.stop);
242	cpu5wdt_device.queue = 0;
243
244	clear_bit(0, &cpu5wdt_device.inuse);
245
246	init_timer(&cpu5wdt_device.timer);
247	cpu5wdt_device.timer.function = cpu5wdt_trigger;
248	cpu5wdt_device.timer.data = 0;
249
250	cpu5wdt_device.default_ticks = ticks;
251
252	printk(KERN_INFO PFX "init success\n");
253
254	return 0;
255
256	no_port:
257	misc_deregister(&cpu5wdt_misc);
258	no_misc:
259	return err;
260	}
261
262	static int __devinit cpu5wdt_init_module(void)
263	{
264	return cpu5wdt_init();
265	}
266
267	static void __devexit cpu5wdt_exit(void)
268	{
269	if ( cpu5wdt_device.queue ) {
270	cpu5wdt_device.queue = 0;
271	down(&cpu5wdt_device.stop);
272	}
273
274	misc_deregister(&cpu5wdt_misc);
275
276	release_region(port, CPU5WDT_EXTENT);
277
278	}
279
280	static void __devexit cpu5wdt_exit_module(void)
281	{
282	cpu5wdt_exit();
283	}
284
285	/* module entry points */
286
287	module_init(cpu5wdt_init_module);
288	module_exit(cpu5wdt_exit_module);
289
290	MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
291	MODULE_DESCRIPTION("sma cpu5 watchdog driver");
292	MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
293	MODULE_LICENSE("GPL");
294	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
295
296	module_param(port, int, 0);
297	MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
298
299	module_param(verbose, int, 0);
300	MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
301
302	module_param(ticks, int, 0);
303	MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");