drivers/char/watchdog/cpu5wdt.c - third_party/linux - Git at Google

 /*
  * 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");
	/*
	* 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");