drivers/watchdog/ziirave_wdt.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2015 Zodiac Inflight Innovations
  *
  * Author: Martyn Welch <martyn.welch@collabora.co.uk>
  *
  * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
  *
  * Copyright (C) Nokia Corporation
  *
  * 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.
  */

 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
 #include <linux/version.h>
 #include <linux/watchdog.h>

 #define ZIIRAVE_TIMEOUT_MIN	3
 #define ZIIRAVE_TIMEOUT_MAX	255

 #define ZIIRAVE_PING_VALUE	0x0

 #define ZIIRAVE_STATE_INITIAL	0x0
 #define ZIIRAVE_STATE_OFF	0x1
 #define ZIIRAVE_STATE_ON	0x2

 static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
 				  "host request", NULL, "illegal configuration",
 				  "illegal instruction", "illegal trap",
 				  "unknown"};

 #define ZIIRAVE_WDT_FIRM_VER_MAJOR	0x1
 #define ZIIRAVE_WDT_BOOT_VER_MAJOR	0x3
 #define ZIIRAVE_WDT_RESET_REASON	0x5
 #define ZIIRAVE_WDT_STATE		0x6
 #define ZIIRAVE_WDT_TIMEOUT		0x7
 #define ZIIRAVE_WDT_TIME_LEFT		0x8
 #define ZIIRAVE_WDT_PING		0x9
 #define ZIIRAVE_WDT_RESET_DURATION	0xa

 struct ziirave_wdt_rev {
 	unsigned char major;
 	unsigned char minor;
 };

 struct ziirave_wdt_data {
 	struct watchdog_device wdd;
 	struct ziirave_wdt_rev bootloader_rev;
 	struct ziirave_wdt_rev firmware_rev;
 	int reset_reason;
 };

 static int wdt_timeout;
 module_param(wdt_timeout, int, 0);
 MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");

 static int reset_duration;
 module_param(reset_duration, int, 0);
 MODULE_PARM_DESC(reset_duration,
 		 "Watchdog reset pulse duration in milliseconds");

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

 static int ziirave_wdt_revision(struct i2c_client *client,
 				struct ziirave_wdt_rev *rev, u8 command)
 {
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, command);
 	if (ret < 0)
 		return ret;

 	rev->major = ret;

 	ret = i2c_smbus_read_byte_data(client, command + 1);
 	if (ret < 0)
 		return ret;

 	rev->minor = ret;

 	return 0;
 }

 static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
 {
 	struct i2c_client *client = to_i2c_client(wdd->parent);

 	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
 }

 static int ziirave_wdt_start(struct watchdog_device *wdd)
 {
 	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
 }

 static int ziirave_wdt_stop(struct watchdog_device *wdd)
 {
 	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
 }

 static int ziirave_wdt_ping(struct watchdog_device *wdd)
 {
 	struct i2c_client *client = to_i2c_client(wdd->parent);

 	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
 					 ZIIRAVE_PING_VALUE);
 }

 static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
 				   unsigned int timeout)
 {
 	struct i2c_client *client = to_i2c_client(wdd->parent);
 	int ret;

 	ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
 	if (!ret)
 		wdd->timeout = timeout;

 	return ret;
 }

 static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
 {
 	struct i2c_client *client = to_i2c_client(wdd->parent);
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
 	if (ret < 0)
 		ret = 0;

 	return ret;
 }

 static const struct watchdog_info ziirave_wdt_info = {
 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
 	.identity = "Zodiac RAVE Watchdog",
 };

 static const struct watchdog_ops ziirave_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= ziirave_wdt_start,
 	.stop		= ziirave_wdt_stop,
 	.ping		= ziirave_wdt_ping,
 	.set_timeout	= ziirave_wdt_set_timeout,
 	.get_timeleft	= ziirave_wdt_get_timeleft,
 };

 static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
 					   struct device_attribute *attr,
 					   char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev->parent);
 	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

 	return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
 		       w_priv->firmware_rev.minor);
 }

 static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
 		   NULL);

 static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
 					   struct device_attribute *attr,
 					   char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev->parent);
 	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

 	return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
 		       w_priv->bootloader_rev.minor);
 }

 static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
 		   NULL);

 static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
 					     struct device_attribute *attr,
 					     char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev->parent);
 	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

 	return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
 }

 static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
 		   NULL);

 static struct attribute *ziirave_wdt_attrs[] = {
 	&dev_attr_firmware_version.attr,
 	&dev_attr_bootloader_version.attr,
 	&dev_attr_reset_reason.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(ziirave_wdt);

 static int ziirave_wdt_init_duration(struct i2c_client *client)
 {
 	int ret;

 	if (!reset_duration) {
 		/* See if the reset pulse duration is provided in an of_node */
 		if (!client->dev.of_node)
 			ret = -ENODEV;
 		else
 			ret = of_property_read_u32(client->dev.of_node,
 						   "reset-duration-ms",
 						   &reset_duration);
 		if (ret) {
 			dev_info(&client->dev,
 				 "Unable to set reset pulse duration, using default\n");
 			return 0;
 		}
 	}

 	if (reset_duration < 1 || reset_duration > 255)
 		return -EINVAL;

 	dev_info(&client->dev, "Setting reset duration to %dms",
 		 reset_duration);

 	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
 					 reset_duration);
 }

 static int ziirave_wdt_probe(struct i2c_client *client,
 			     const struct i2c_device_id *id)
 {
 	int ret;
 	struct ziirave_wdt_data *w_priv;
 	int val;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -ENODEV;

 	w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
 	if (!w_priv)
 		return -ENOMEM;

 	w_priv->wdd.info = &ziirave_wdt_info;
 	w_priv->wdd.ops = &ziirave_wdt_ops;
 	w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
 	w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
 	w_priv->wdd.parent = &client->dev;
 	w_priv->wdd.groups = ziirave_wdt_groups;

 	ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
 	if (ret) {
 		dev_info(&client->dev,
 			 "Unable to select timeout value, using default\n");
 	}

 	/*
 	 * The default value set in the watchdog should be perfectly valid, so
 	 * pass that in if we haven't provided one via the module parameter or
 	 * of property.
 	 */
 	if (w_priv->wdd.timeout == 0) {
 		val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
 		if (val < 0)
 			return val;

 		if (val < ZIIRAVE_TIMEOUT_MIN)
 			return -ENODEV;

 		w_priv->wdd.timeout = val;
 	} else {
 		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
 					      w_priv->wdd.timeout);
 		if (ret)
 			return ret;

 		dev_info(&client->dev, "Timeout set to %ds.",
 			 w_priv->wdd.timeout);
 	}

 	watchdog_set_nowayout(&w_priv->wdd, nowayout);

 	i2c_set_clientdata(client, w_priv);

 	/* If in unconfigured state, set to stopped */
 	val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
 	if (val < 0)
 		return val;

 	if (val == ZIIRAVE_STATE_INITIAL)
 		ziirave_wdt_stop(&w_priv->wdd);

 	ret = ziirave_wdt_init_duration(client);
 	if (ret)
 		return ret;

 	ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
 				   ZIIRAVE_WDT_FIRM_VER_MAJOR);
 	if (ret)
 		return ret;

 	ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
 				   ZIIRAVE_WDT_BOOT_VER_MAJOR);
 	if (ret)
 		return ret;

 	w_priv->reset_reason = i2c_smbus_read_byte_data(client,
 						ZIIRAVE_WDT_RESET_REASON);
 	if (w_priv->reset_reason < 0)
 		return w_priv->reset_reason;

 	if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
 	    !ziirave_reasons[w_priv->reset_reason])
 		return -ENODEV;

 	ret = watchdog_register_device(&w_priv->wdd);

 	return ret;
 }

 static int ziirave_wdt_remove(struct i2c_client *client)
 {
 	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

 	watchdog_unregister_device(&w_priv->wdd);

 	return 0;
 }

 static struct i2c_device_id ziirave_wdt_id[] = {
 	{ "ziirave-wdt", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);

 static const struct of_device_id zrv_wdt_of_match[] = {
 	{ .compatible = "zii,rave-wdt", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);

 static struct i2c_driver ziirave_wdt_driver = {
 	.driver = {
 		.name = "ziirave_wdt",
 		.of_match_table = zrv_wdt_of_match,
 	},
 	.probe = ziirave_wdt_probe,
 	.remove = ziirave_wdt_remove,
 	.id_table = ziirave_wdt_id,
 };

 module_i2c_driver(ziirave_wdt_driver);

 MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
 MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2015 Zodiac Inflight Innovations
	*
	* Author: Martyn Welch <martyn.welch@collabora.co.uk>
	*
	* Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
	*
	* Copyright (C) Nokia Corporation
	*
	* 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.
	*/

	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>
	#include <linux/types.h>
	#include <linux/version.h>
	#include <linux/watchdog.h>

	#define ZIIRAVE_TIMEOUT_MIN 3
	#define ZIIRAVE_TIMEOUT_MAX 255

	#define ZIIRAVE_PING_VALUE 0x0

	#define ZIIRAVE_STATE_INITIAL 0x0
	#define ZIIRAVE_STATE_OFF 0x1
	#define ZIIRAVE_STATE_ON 0x2

	static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
	"host request", NULL, "illegal configuration",
	"illegal instruction", "illegal trap",
	"unknown"};

	#define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1
	#define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3
	#define ZIIRAVE_WDT_RESET_REASON 0x5
	#define ZIIRAVE_WDT_STATE 0x6
	#define ZIIRAVE_WDT_TIMEOUT 0x7
	#define ZIIRAVE_WDT_TIME_LEFT 0x8
	#define ZIIRAVE_WDT_PING 0x9
	#define ZIIRAVE_WDT_RESET_DURATION 0xa

	struct ziirave_wdt_rev {
	unsigned char major;
	unsigned char minor;
	};

	struct ziirave_wdt_data {
	struct watchdog_device wdd;
	struct ziirave_wdt_rev bootloader_rev;
	struct ziirave_wdt_rev firmware_rev;
	int reset_reason;
	};

	static int wdt_timeout;
	module_param(wdt_timeout, int, 0);
	MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");

	static int reset_duration;
	module_param(reset_duration, int, 0);
	MODULE_PARM_DESC(reset_duration,
	"Watchdog reset pulse duration in milliseconds");

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

	static int ziirave_wdt_revision(struct i2c_client *client,
	struct ziirave_wdt_rev *rev, u8 command)
	{
	int ret;

	ret = i2c_smbus_read_byte_data(client, command);
	if (ret < 0)
	return ret;

	rev->major = ret;

	ret = i2c_smbus_read_byte_data(client, command + 1);
	if (ret < 0)
	return ret;

	rev->minor = ret;

	return 0;
	}

	static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
	{
	struct i2c_client *client = to_i2c_client(wdd->parent);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
	}

	static int ziirave_wdt_start(struct watchdog_device *wdd)
	{
	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
	}

	static int ziirave_wdt_stop(struct watchdog_device *wdd)
	{
	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
	}

	static int ziirave_wdt_ping(struct watchdog_device *wdd)
	{
	struct i2c_client *client = to_i2c_client(wdd->parent);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
	ZIIRAVE_PING_VALUE);
	}

	static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
	unsigned int timeout)
	{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;

	ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
	if (!ret)
	wdd->timeout = timeout;

	return ret;
	}

	static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
	{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;

	ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
	if (ret < 0)
	ret = 0;

	return ret;
	}

	static const struct watchdog_info ziirave_wdt_info = {
	.options = WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE \| WDIOF_KEEPALIVEPING,
	.identity = "Zodiac RAVE Watchdog",
	};

	static const struct watchdog_ops ziirave_wdt_ops = {
	.owner = THIS_MODULE,
	.start = ziirave_wdt_start,
	.stop = ziirave_wdt_stop,
	.ping = ziirave_wdt_ping,
	.set_timeout = ziirave_wdt_set_timeout,
	.get_timeleft = ziirave_wdt_get_timeleft,
	};

	static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

	return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
	w_priv->firmware_rev.minor);
	}

	static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
	NULL);

	static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

	return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
	w_priv->bootloader_rev.minor);
	}

	static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
	NULL);

	static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

	return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
	}

	static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
	NULL);

	static struct attribute *ziirave_wdt_attrs[] = {
	&dev_attr_firmware_version.attr,
	&dev_attr_bootloader_version.attr,
	&dev_attr_reset_reason.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(ziirave_wdt);

	static int ziirave_wdt_init_duration(struct i2c_client *client)
	{
	int ret;

	if (!reset_duration) {
	/* See if the reset pulse duration is provided in an of_node */
	if (!client->dev.of_node)
	ret = -ENODEV;
	else
	ret = of_property_read_u32(client->dev.of_node,
	"reset-duration-ms",
	&reset_duration);
	if (ret) {
	dev_info(&client->dev,
	"Unable to set reset pulse duration, using default\n");
	return 0;
	}
	}

	if (reset_duration < 1 \|\| reset_duration > 255)
	return -EINVAL;

	dev_info(&client->dev, "Setting reset duration to %dms",
	reset_duration);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
	reset_duration);
	}

	static int ziirave_wdt_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct ziirave_wdt_data *w_priv;
	int val;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	return -ENODEV;

	w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
	if (!w_priv)
	return -ENOMEM;

	w_priv->wdd.info = &ziirave_wdt_info;
	w_priv->wdd.ops = &ziirave_wdt_ops;
	w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
	w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
	w_priv->wdd.parent = &client->dev;
	w_priv->wdd.groups = ziirave_wdt_groups;

	ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
	if (ret) {
	dev_info(&client->dev,
	"Unable to select timeout value, using default\n");
	}

	/*
	* The default value set in the watchdog should be perfectly valid, so
	* pass that in if we haven't provided one via the module parameter or
	* of property.
	*/
	if (w_priv->wdd.timeout == 0) {
	val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
	if (val < 0)
	return val;

	if (val < ZIIRAVE_TIMEOUT_MIN)
	return -ENODEV;

	w_priv->wdd.timeout = val;
	} else {
	ret = ziirave_wdt_set_timeout(&w_priv->wdd,
	w_priv->wdd.timeout);
	if (ret)
	return ret;

	dev_info(&client->dev, "Timeout set to %ds.",
	w_priv->wdd.timeout);
	}

	watchdog_set_nowayout(&w_priv->wdd, nowayout);

	i2c_set_clientdata(client, w_priv);

	/* If in unconfigured state, set to stopped */
	val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
	if (val < 0)
	return val;

	if (val == ZIIRAVE_STATE_INITIAL)
	ziirave_wdt_stop(&w_priv->wdd);

	ret = ziirave_wdt_init_duration(client);
	if (ret)
	return ret;

	ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
	ZIIRAVE_WDT_FIRM_VER_MAJOR);
	if (ret)
	return ret;

	ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
	ZIIRAVE_WDT_BOOT_VER_MAJOR);
	if (ret)
	return ret;

	w_priv->reset_reason = i2c_smbus_read_byte_data(client,
	ZIIRAVE_WDT_RESET_REASON);
	if (w_priv->reset_reason < 0)
	return w_priv->reset_reason;

	if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) \|\|
	!ziirave_reasons[w_priv->reset_reason])
	return -ENODEV;

	ret = watchdog_register_device(&w_priv->wdd);

	return ret;
	}

	static int ziirave_wdt_remove(struct i2c_client *client)
	{
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

	watchdog_unregister_device(&w_priv->wdd);

	return 0;
	}

	static struct i2c_device_id ziirave_wdt_id[] = {
	{ "ziirave-wdt", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);

	static const struct of_device_id zrv_wdt_of_match[] = {
	{ .compatible = "zii,rave-wdt", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);

	static struct i2c_driver ziirave_wdt_driver = {
	.driver = {
	.name = "ziirave_wdt",
	.of_match_table = zrv_wdt_of_match,
	},
	.probe = ziirave_wdt_probe,
	.remove = ziirave_wdt_remove,
	.id_table = ziirave_wdt_id,
	};

	module_i2c_driver(ziirave_wdt_driver);

	MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
	MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
	MODULE_LICENSE("GPL");