wdrtas.c

linux-2.6.15.6

		return put_user(i, argp);

	case WDIOC_SETOPTIONS:
		if (get_user(i, argp))
			return -EFAULT;
		if (i & WDIOS_DISABLECARD)
			wdrtas_timer_stop();
		if (i & WDIOS_ENABLECARD) {
			wdrtas_timer_keepalive();
			wdrtas_timer_start();
		}
		if (i & WDIOS_TEMPPANIC) {
			/* not implemented. Done by H8 */
		}
		return 0;

	case WDIOC_KEEPALIVE:
		wdrtas_timer_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(i, argp))
			return -EFAULT;

		if (wdrtas_set_interval(i))
			return -EINVAL;

		wdrtas_timer_keepalive();

		if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
			wdrtas_interval = i;
		else
			wdrtas_interval = wdrtas_get_interval(i);
		/* fallthrough */

	case WDIOC_GETTIMEOUT:
		return put_user(wdrtas_interval, argp);

	default:
		return -ENOIOCTLCMD;
	}
}

/**
 * wdrtas_open - open function of watchdog device
 * @inode: inode structure
 * @file: file structure
 *
 * returns 0 on success, -EBUSY if the file has been opened already, <0 on
 * other failures
 *
 * function called when watchdog device is opened
 */
static int
wdrtas_open(struct inode *inode, struct file *file)
{
	/* only open once */
	if (atomic_inc_return(&wdrtas_miscdev_open) > 1) {
		atomic_dec(&wdrtas_miscdev_open);
		return -EBUSY;
	}

	wdrtas_timer_start();
	wdrtas_timer_keepalive();

	return nonseekable_open(inode, file);
}

/**
 * wdrtas_close - close function of watchdog device
 * @inode: inode structure
 * @file: file structure
 *
 * returns 0 on success
 *
 * close function. Always succeeds
 */
static int
wdrtas_close(struct inode *inode, struct file *file)
{
	/* only stop watchdog, if this was announced using 'V' before */
	if (wdrtas_expect_close == WDRTAS_MAGIC_CHAR)
		wdrtas_timer_stop();
	else {
		printk(KERN_WARNING "wdrtas: got unexpected close. Watchdog "
		       "not stopped.\n");
		wdrtas_timer_keepalive();
	}

	wdrtas_expect_close = 0;
	atomic_dec(&wdrtas_miscdev_open);
	return 0;
}

/**
 * wdrtas_temp_read - gives back the temperature in fahrenheit
 * @file: file structure
 * @buf: user buffer
 * @count: number of bytes to be read
 * @ppos: position in file
 *
 * returns always 1 or -EFAULT in case of user space copy failures, <0 on
 * other failures
 *
 * wdrtas_temp_read gives the temperature to the users by copying this
 * value as one byte into the user space buffer. The unit is Fahrenheit...
 */
static ssize_t
wdrtas_temp_read(struct file *file, char __user *buf,
		 size_t count, loff_t *ppos)
{
	int temperature = 0;

	temperature = wdrtas_get_temperature();
	if (temperature < 0)
		return temperature;

	if (copy_to_user(buf, &temperature, 1))
		return -EFAULT;

	return 1;
}

/**
 * wdrtas_temp_open - open function of temperature device
 * @inode: inode structure
 * @file: file structure
 *
 * returns 0 on success, <0 on failure
 *
 * function called when temperature device is opened
 */
static int
wdrtas_temp_open(struct inode *inode, struct file *file)
{
	return nonseekable_open(inode, file);
}

/**
 * wdrtas_temp_close - close function of temperature device
 * @inode: inode structure
 * @file: file structure
 *
 * returns 0 on success
 *
 * close function. Always succeeds
 */
static int
wdrtas_temp_close(struct inode *inode, struct file *file)
{
	return 0;
}

/**
 * wdrtas_reboot - reboot notifier function
 * @nb: notifier block structure
 * @code: reboot code
 * @ptr: unused
 *
 * returns NOTIFY_DONE
 *
 * wdrtas_reboot stops the watchdog in case of a reboot
 */
static int
wdrtas_reboot(struct notifier_block *this, unsigned long code, void *ptr)
{
	if ( (code==SYS_DOWN) || (code==SYS_HALT) )
		wdrtas_timer_stop();

	return NOTIFY_DONE;
}

/*** initialization stuff */

static struct file_operations wdrtas_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wdrtas_write,
	.ioctl		= wdrtas_ioctl,
	.open		= wdrtas_open,
	.release	= wdrtas_close,
};

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

static struct file_operations wdrtas_temp_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= wdrtas_temp_read,
	.open		= wdrtas_temp_open,
	.release	= wdrtas_temp_close,
};

static struct miscdevice wdrtas_tempdev = {
	.minor =	TEMP_MINOR,
	.name =		"temperature",
	.fops =		&wdrtas_temp_fops,
};

static struct notifier_block wdrtas_notifier = {
	.notifier_call =	wdrtas_reboot,
};

/**
 * wdrtas_get_tokens - reads in RTAS tokens
 *
 * returns 0 on succes, <0 on failure
 *
 * wdrtas_get_tokens reads in the tokens for the RTAS calls used in
 * this watchdog driver. It tolerates, if "get-sensor-state" and
 * "ibm,get-system-parameter" are not available.
 */
static int
wdrtas_get_tokens(void)
{
	wdrtas_token_get_sensor_state = rtas_token("get-sensor-state");
	if (wdrtas_token_get_sensor_state == RTAS_UNKNOWN_SERVICE) {
		printk(KERN_WARNING "wdrtas: couldn't get token for "
		       "get-sensor-state. Trying to continue without "
		       "temperature support.\n");
	}

	wdrtas_token_get_sp = rtas_token("ibm,get-system-parameter");
	if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE) {
		printk(KERN_WARNING "wdrtas: couldn't get token for "
		       "ibm,get-system-parameter. Trying to continue with "
		       "a default timeout value of %i seconds.\n",
		       WDRTAS_DEFAULT_INTERVAL);
	}

	wdrtas_token_set_indicator = rtas_token("set-indicator");
	if (wdrtas_token_set_indicator == RTAS_UNKNOWN_SERVICE) {
		printk(KERN_ERR "wdrtas: couldn't get token for "
		       "set-indicator. Terminating watchdog code.\n");
		return -EIO;
	}

	wdrtas_token_event_scan = rtas_token("event-scan");
	if (wdrtas_token_event_scan == RTAS_UNKNOWN_SERVICE) {
		printk(KERN_ERR "wdrtas: couldn't get token for event-scan. "
		       "Terminating watchdog code.\n");
		return -EIO;
	}

	return 0;
}

/**
 * wdrtas_unregister_devs - unregisters the misc dev handlers
 *
 * wdrtas_register_devs unregisters the watchdog and temperature watchdog
 * misc devs
 */
static void
wdrtas_unregister_devs(void)
{
	misc_deregister(&wdrtas_miscdev);
	if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE)
		misc_deregister(&wdrtas_tempdev);
}

/**
 * wdrtas_register_devs - registers the misc dev handlers
 *
 * returns 0 on succes, <0 on failure
 *
 * wdrtas_register_devs registers the watchdog and temperature watchdog
 * misc devs
 */
static int
wdrtas_register_devs(void)
{
	int result;

	result = misc_register(&wdrtas_miscdev);
	if (result) {
		printk(KERN_ERR "wdrtas: couldn't register watchdog misc "
		       "device. Terminating watchdog code.\n");
		return result;
	}

	if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE) {
		result = misc_register(&wdrtas_tempdev);
		if (result) {
			printk(KERN_WARNING "wdrtas: couldn't register "
			       "watchdog temperature misc device. Continuing "
			       "without temperature support.\n");
			wdrtas_token_get_sensor_state = RTAS_UNKNOWN_SERVICE;
		}
	}

	return 0;
}

/**
 * wdrtas_init - init function of the watchdog driver
 *
 * returns 0 on succes, <0 on failure
 *
 * registers the file handlers and the reboot notifier
 */
static int __init
wdrtas_init(void)
{
	if (wdrtas_get_tokens())
		return -ENODEV;

	if (wdrtas_register_devs())
		return -ENODEV;

	if (register_reboot_notifier(&wdrtas_notifier)) {
		printk(KERN_ERR "wdrtas: could not register reboot notifier. "
		       "Terminating watchdog code.\n");
		wdrtas_unregister_devs();
		return -ENODEV;
	}

	if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
		wdrtas_interval = WDRTAS_DEFAULT_INTERVAL;
	else
		wdrtas_interval = wdrtas_get_interval(WDRTAS_DEFAULT_INTERVAL);

	return 0;
}

/**
 * wdrtas_exit - exit function of the watchdog driver
 *
 * unregisters the file handlers and the reboot notifier
 */
static void __exit
wdrtas_exit(void)
{
	if (!wdrtas_nowayout)
		wdrtas_timer_stop();

	wdrtas_unregister_devs();

	unregister_reboot_notifier(&wdrtas_notifier);
}

module_init(wdrtas_init);
module_exit(wdrtas_exit);