drivers/hwmon/s3c-hwmon.c - linux - Git at Google

 /* linux/drivers/hwmon/s3c-hwmon.c
  *
  * Copyright (C) 2005, 2008, 2009 Simtec Electronics
  *	http://armlinux.simtec.co.uk/
  *	Ben Dooks <ben@simtec.co.uk>
  *
  * S3C24XX/S3C64XX ADC hwmon support
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * 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/slab.h>
 #include <linux/io.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>

 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>

 #include <plat/adc.h>
 #include <linux/platform_data/hwmon-s3c.h>

 struct s3c_hwmon_attr {
 	struct sensor_device_attribute	in;
 	struct sensor_device_attribute	label;
 	char				in_name[12];
 	char				label_name[12];
 };

 /**
  * struct s3c_hwmon - ADC hwmon client information
  * @lock: Access lock to serialise the conversions.
  * @client: The client we registered with the S3C ADC core.
  * @hwmon_dev: The hwmon device we created.
  * @attr: The holders for the channel attributes.
 */
 struct s3c_hwmon {
 	struct mutex		lock;
 	struct s3c_adc_client	*client;
 	struct device		*hwmon_dev;

 	struct s3c_hwmon_attr	attrs[8];
 };

 /**
  * s3c_hwmon_read_ch - read a value from a given adc channel.
  * @dev: The device.
  * @hwmon: Our state.
  * @channel: The channel we're reading from.
  *
  * Read a value from the @channel with the proper locking and sleep until
  * either the read completes or we timeout awaiting the ADC core to get
  * back to us.
  */
 static int s3c_hwmon_read_ch(struct device *dev,
 			     struct s3c_hwmon *hwmon, int channel)
 {
 	int ret;

 	ret = mutex_lock_interruptible(&hwmon->lock);
 	if (ret < 0)
 		return ret;

 	dev_dbg(dev, "reading channel %d\n", channel);

 	ret = s3c_adc_read(hwmon->client, channel);
 	mutex_unlock(&hwmon->lock);

 	return ret;
 }

 #ifdef CONFIG_SENSORS_S3C_RAW
 /**
  * s3c_hwmon_show_raw - show a conversion from the raw channel number.
  * @dev: The device that the attribute belongs to.
  * @attr: The attribute being read.
  * @buf: The result buffer.
  *
  * This show deals with the raw attribute, registered for each possible
  * ADC channel. This does a conversion and returns the raw (un-scaled)
  * value returned from the hardware.
  */
 static ssize_t s3c_hwmon_show_raw(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
 	struct s3c_hwmon *adc = dev_get_drvdata(dev);
 	struct sensor_device_attribute *sa = to_sensor_dev_attr(attr);
 	int ret;

 	ret = s3c_hwmon_read_ch(dev, adc, sa->index);

 	return  (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret);
 }

 static SENSOR_DEVICE_ATTR(adc0_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 0);
 static SENSOR_DEVICE_ATTR(adc1_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 1);
 static SENSOR_DEVICE_ATTR(adc2_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 2);
 static SENSOR_DEVICE_ATTR(adc3_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 3);
 static SENSOR_DEVICE_ATTR(adc4_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 4);
 static SENSOR_DEVICE_ATTR(adc5_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 5);
 static SENSOR_DEVICE_ATTR(adc6_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 6);
 static SENSOR_DEVICE_ATTR(adc7_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 7);

 static struct attribute *s3c_hwmon_attrs[9] = {
 	&sensor_dev_attr_adc0_raw.dev_attr.attr,
 	&sensor_dev_attr_adc1_raw.dev_attr.attr,
 	&sensor_dev_attr_adc2_raw.dev_attr.attr,
 	&sensor_dev_attr_adc3_raw.dev_attr.attr,
 	&sensor_dev_attr_adc4_raw.dev_attr.attr,
 	&sensor_dev_attr_adc5_raw.dev_attr.attr,
 	&sensor_dev_attr_adc6_raw.dev_attr.attr,
 	&sensor_dev_attr_adc7_raw.dev_attr.attr,
 	NULL,
 };

 static struct attribute_group s3c_hwmon_attrgroup = {
 	.attrs	= s3c_hwmon_attrs,
 };

 static inline int s3c_hwmon_add_raw(struct device *dev)
 {
 	return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup);
 }

 static inline void s3c_hwmon_remove_raw(struct device *dev)
 {
 	sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup);
 }

 #else

 static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; }
 static inline void s3c_hwmon_remove_raw(struct device *dev) { }

 #endif /* CONFIG_SENSORS_S3C_RAW */

 /**
  * s3c_hwmon_ch_show - show value of a given channel
  * @dev: The device that the attribute belongs to.
  * @attr: The attribute being read.
  * @buf: The result buffer.
  *
  * Read a value from the ADC and scale it before returning it to the
  * caller. The scale factor is gained from the channel configuration
  * passed via the platform data when the device was registered.
  */
 static ssize_t s3c_hwmon_ch_show(struct device *dev,
 				 struct device_attribute *attr,
 				 char *buf)
 {
 	struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
 	struct s3c_hwmon *hwmon = dev_get_drvdata(dev);
 	struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
 	struct s3c_hwmon_chcfg *cfg;
 	int ret;

 	cfg = pdata->in[sen_attr->index];

 	ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index);
 	if (ret < 0)
 		return ret;

 	ret *= cfg->mult;
 	ret = DIV_ROUND_CLOSEST(ret, cfg->div);

 	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
 }

 /**
  * s3c_hwmon_label_show - show label name of the given channel.
  * @dev: The device that the attribute belongs to.
  * @attr: The attribute being read.
  * @buf: The result buffer.
  *
  * Return the label name of a given channel
  */
 static ssize_t s3c_hwmon_label_show(struct device *dev,
 				    struct device_attribute *attr,
 				    char *buf)
 {
 	struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
 	struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
 	struct s3c_hwmon_chcfg *cfg;

 	cfg = pdata->in[sen_attr->index];

 	return snprintf(buf, PAGE_SIZE, "%s\n", cfg->name);
 }

 /**
  * s3c_hwmon_create_attr - create hwmon attribute for given channel.
  * @dev: The device to create the attribute on.
  * @cfg: The channel configuration passed from the platform data.
  * @channel: The ADC channel number to process.
  *
  * Create the scaled attribute for use with hwmon from the specified
  * platform data in @pdata. The sysfs entry is handled by the routine
  * s3c_hwmon_ch_show().
  *
  * The attribute name is taken from the configuration data if present
  * otherwise the name is taken by concatenating in_ with the channel
  * number.
  */
 static int s3c_hwmon_create_attr(struct device *dev,
 				 struct s3c_hwmon_chcfg *cfg,
 				 struct s3c_hwmon_attr *attrs,
 				 int channel)
 {
 	struct sensor_device_attribute *attr;
 	int ret;

 	snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel);

 	attr = &attrs->in;
 	attr->index = channel;
 	sysfs_attr_init(&attr->dev_attr.attr);
 	attr->dev_attr.attr.name  = attrs->in_name;
 	attr->dev_attr.attr.mode  = S_IRUGO;
 	attr->dev_attr.show = s3c_hwmon_ch_show;

 	ret =  device_create_file(dev, &attr->dev_attr);
 	if (ret < 0) {
 		dev_err(dev, "failed to create input attribute\n");
 		return ret;
 	}

 	/* if this has a name, add a label */
 	if (cfg->name) {
 		snprintf(attrs->label_name, sizeof(attrs->label_name),
 			 "in%d_label", channel);

 		attr = &attrs->label;
 		attr->index = channel;
 		sysfs_attr_init(&attr->dev_attr.attr);
 		attr->dev_attr.attr.name  = attrs->label_name;
 		attr->dev_attr.attr.mode  = S_IRUGO;
 		attr->dev_attr.show = s3c_hwmon_label_show;

 		ret = device_create_file(dev, &attr->dev_attr);
 		if (ret < 0) {
 			device_remove_file(dev, &attrs->in.dev_attr);
 			dev_err(dev, "failed to create label attribute\n");
 		}
 	}

 	return ret;
 }

 static void s3c_hwmon_remove_attr(struct device *dev,
 				  struct s3c_hwmon_attr *attrs)
 {
 	device_remove_file(dev, &attrs->in.dev_attr);
 	device_remove_file(dev, &attrs->label.dev_attr);
 }

 /**
  * s3c_hwmon_probe - device probe entry.
  * @dev: The device being probed.
 */
 static int s3c_hwmon_probe(struct platform_device *dev)
 {
 	struct s3c_hwmon_pdata *pdata = dev_get_platdata(&dev->dev);
 	struct s3c_hwmon *hwmon;
 	int ret = 0;
 	int i;

 	if (!pdata) {
 		dev_err(&dev->dev, "no platform data supplied\n");
 		return -EINVAL;
 	}

 	hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL);
 	if (hwmon == NULL)
 		return -ENOMEM;

 	platform_set_drvdata(dev, hwmon);

 	mutex_init(&hwmon->lock);

 	/* Register with the core ADC driver. */

 	hwmon->client = s3c_adc_register(dev, NULL, NULL, 0);
 	if (IS_ERR(hwmon->client)) {
 		dev_err(&dev->dev, "cannot register adc\n");
 		return PTR_ERR(hwmon->client);
 	}

 	/* add attributes for our adc devices. */

 	ret = s3c_hwmon_add_raw(&dev->dev);
 	if (ret)
 		goto err_registered;

 	/* register with the hwmon core */

 	hwmon->hwmon_dev = hwmon_device_register(&dev->dev);
 	if (IS_ERR(hwmon->hwmon_dev)) {
 		dev_err(&dev->dev, "error registering with hwmon\n");
 		ret = PTR_ERR(hwmon->hwmon_dev);
 		goto err_raw_attribute;
 	}

 	for (i = 0; i < ARRAY_SIZE(pdata->in); i++) {
 		struct s3c_hwmon_chcfg *cfg = pdata->in[i];

 		if (!cfg)
 			continue;

 		if (cfg->mult >= 0x10000)
 			dev_warn(&dev->dev,
 				 "channel %d multiplier too large\n",
 				 i);

 		if (cfg->div == 0) {
 			dev_err(&dev->dev, "channel %d divider zero\n", i);
 			continue;
 		}

 		ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i],
 					    &hwmon->attrs[i], i);
 		if (ret) {
 			dev_err(&dev->dev,
 					"error creating channel %d\n", i);

 			for (i--; i >= 0; i--)
 				s3c_hwmon_remove_attr(&dev->dev,
 							      &hwmon->attrs[i]);

 			goto err_hwmon_register;
 		}
 	}

 	return 0;

  err_hwmon_register:
 	hwmon_device_unregister(hwmon->hwmon_dev);

  err_raw_attribute:
 	s3c_hwmon_remove_raw(&dev->dev);

  err_registered:
 	s3c_adc_release(hwmon->client);

 	return ret;
 }

 static int s3c_hwmon_remove(struct platform_device *dev)
 {
 	struct s3c_hwmon *hwmon = platform_get_drvdata(dev);
 	int i;

 	s3c_hwmon_remove_raw(&dev->dev);

 	for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++)
 		s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]);

 	hwmon_device_unregister(hwmon->hwmon_dev);
 	s3c_adc_release(hwmon->client);

 	return 0;
 }

 static struct platform_driver s3c_hwmon_driver = {
 	.driver	= {
 		.name		= "s3c-hwmon",
 	},
 	.probe		= s3c_hwmon_probe,
 	.remove		= s3c_hwmon_remove,
 };

 module_platform_driver(s3c_hwmon_driver);

 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 MODULE_DESCRIPTION("S3C ADC HWMon driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:s3c-hwmon");
	/* linux/drivers/hwmon/s3c-hwmon.c
	*
	* Copyright (C) 2005, 2008, 2009 Simtec Electronics
	* http://armlinux.simtec.co.uk/
	* Ben Dooks <ben@simtec.co.uk>
	*
	* S3C24XX/S3C64XX ADC hwmon support
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* 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/slab.h>
	#include <linux/io.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/clk.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>

	#include <linux/hwmon.h>
	#include <linux/hwmon-sysfs.h>

	#include <plat/adc.h>
	#include <linux/platform_data/hwmon-s3c.h>

	struct s3c_hwmon_attr {
	struct sensor_device_attribute in;
	struct sensor_device_attribute label;
	char in_name[12];
	char label_name[12];
	};

	/**
	* struct s3c_hwmon - ADC hwmon client information
	* @lock: Access lock to serialise the conversions.
	* @client: The client we registered with the S3C ADC core.
	* @hwmon_dev: The hwmon device we created.
	* @attr: The holders for the channel attributes.
	*/
	struct s3c_hwmon {
	struct mutex lock;
	struct s3c_adc_client *client;
	struct device *hwmon_dev;

	struct s3c_hwmon_attr attrs[8];
	};

	/**
	* s3c_hwmon_read_ch - read a value from a given adc channel.
	* @dev: The device.
	* @hwmon: Our state.
	* @channel: The channel we're reading from.
	*
	* Read a value from the @channel with the proper locking and sleep until
	* either the read completes or we timeout awaiting the ADC core to get
	* back to us.
	*/
	static int s3c_hwmon_read_ch(struct device *dev,
	struct s3c_hwmon *hwmon, int channel)
	{
	int ret;

	ret = mutex_lock_interruptible(&hwmon->lock);
	if (ret < 0)
	return ret;

	dev_dbg(dev, "reading channel %d\n", channel);

	ret = s3c_adc_read(hwmon->client, channel);
	mutex_unlock(&hwmon->lock);

	return ret;
	}

	#ifdef CONFIG_SENSORS_S3C_RAW
	/**
	* s3c_hwmon_show_raw - show a conversion from the raw channel number.
	* @dev: The device that the attribute belongs to.
	* @attr: The attribute being read.
	* @buf: The result buffer.
	*
	* This show deals with the raw attribute, registered for each possible
	* ADC channel. This does a conversion and returns the raw (un-scaled)
	* value returned from the hardware.
	*/
	static ssize_t s3c_hwmon_show_raw(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct s3c_hwmon *adc = dev_get_drvdata(dev);
	struct sensor_device_attribute *sa = to_sensor_dev_attr(attr);
	int ret;

	ret = s3c_hwmon_read_ch(dev, adc, sa->index);

	return (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret);
	}

	static SENSOR_DEVICE_ATTR(adc0_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 0);
	static SENSOR_DEVICE_ATTR(adc1_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 1);
	static SENSOR_DEVICE_ATTR(adc2_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 2);
	static SENSOR_DEVICE_ATTR(adc3_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 3);
	static SENSOR_DEVICE_ATTR(adc4_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 4);
	static SENSOR_DEVICE_ATTR(adc5_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 5);
	static SENSOR_DEVICE_ATTR(adc6_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 6);
	static SENSOR_DEVICE_ATTR(adc7_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 7);

	static struct attribute *s3c_hwmon_attrs[9] = {
	&sensor_dev_attr_adc0_raw.dev_attr.attr,
	&sensor_dev_attr_adc1_raw.dev_attr.attr,
	&sensor_dev_attr_adc2_raw.dev_attr.attr,
	&sensor_dev_attr_adc3_raw.dev_attr.attr,
	&sensor_dev_attr_adc4_raw.dev_attr.attr,
	&sensor_dev_attr_adc5_raw.dev_attr.attr,
	&sensor_dev_attr_adc6_raw.dev_attr.attr,
	&sensor_dev_attr_adc7_raw.dev_attr.attr,
	NULL,
	};

	static struct attribute_group s3c_hwmon_attrgroup = {
	.attrs = s3c_hwmon_attrs,
	};

	static inline int s3c_hwmon_add_raw(struct device *dev)
	{
	return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup);
	}

	static inline void s3c_hwmon_remove_raw(struct device *dev)
	{
	sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup);
	}

	#else

	static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; }
	static inline void s3c_hwmon_remove_raw(struct device *dev) { }

	#endif /* CONFIG_SENSORS_S3C_RAW */

	/**
	* s3c_hwmon_ch_show - show value of a given channel
	* @dev: The device that the attribute belongs to.
	* @attr: The attribute being read.
	* @buf: The result buffer.
	*
	* Read a value from the ADC and scale it before returning it to the
	* caller. The scale factor is gained from the channel configuration
	* passed via the platform data when the device was registered.
	*/
	static ssize_t s3c_hwmon_ch_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
	struct s3c_hwmon *hwmon = dev_get_drvdata(dev);
	struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
	struct s3c_hwmon_chcfg *cfg;
	int ret;

	cfg = pdata->in[sen_attr->index];

	ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index);
	if (ret < 0)
	return ret;

	ret *= cfg->mult;
	ret = DIV_ROUND_CLOSEST(ret, cfg->div);

	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
	}

	/**
	* s3c_hwmon_label_show - show label name of the given channel.
	* @dev: The device that the attribute belongs to.
	* @attr: The attribute being read.
	* @buf: The result buffer.
	*
	* Return the label name of a given channel
	*/
	static ssize_t s3c_hwmon_label_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
	struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
	struct s3c_hwmon_chcfg *cfg;

	cfg = pdata->in[sen_attr->index];

	return snprintf(buf, PAGE_SIZE, "%s\n", cfg->name);
	}

	/**
	* s3c_hwmon_create_attr - create hwmon attribute for given channel.
	* @dev: The device to create the attribute on.
	* @cfg: The channel configuration passed from the platform data.
	* @channel: The ADC channel number to process.
	*
	* Create the scaled attribute for use with hwmon from the specified
	* platform data in @pdata. The sysfs entry is handled by the routine
	* s3c_hwmon_ch_show().
	*
	* The attribute name is taken from the configuration data if present
	* otherwise the name is taken by concatenating in_ with the channel
	* number.
	*/
	static int s3c_hwmon_create_attr(struct device *dev,
	struct s3c_hwmon_chcfg *cfg,
	struct s3c_hwmon_attr *attrs,
	int channel)
	{
	struct sensor_device_attribute *attr;
	int ret;

	snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel);

	attr = &attrs->in;
	attr->index = channel;
	sysfs_attr_init(&attr->dev_attr.attr);
	attr->dev_attr.attr.name = attrs->in_name;
	attr->dev_attr.attr.mode = S_IRUGO;
	attr->dev_attr.show = s3c_hwmon_ch_show;

	ret = device_create_file(dev, &attr->dev_attr);
	if (ret < 0) {
	dev_err(dev, "failed to create input attribute\n");
	return ret;
	}

	/* if this has a name, add a label */
	if (cfg->name) {
	snprintf(attrs->label_name, sizeof(attrs->label_name),
	"in%d_label", channel);

	attr = &attrs->label;
	attr->index = channel;
	sysfs_attr_init(&attr->dev_attr.attr);
	attr->dev_attr.attr.name = attrs->label_name;
	attr->dev_attr.attr.mode = S_IRUGO;
	attr->dev_attr.show = s3c_hwmon_label_show;

	ret = device_create_file(dev, &attr->dev_attr);
	if (ret < 0) {
	device_remove_file(dev, &attrs->in.dev_attr);
	dev_err(dev, "failed to create label attribute\n");
	}
	}

	return ret;
	}

	static void s3c_hwmon_remove_attr(struct device *dev,
	struct s3c_hwmon_attr *attrs)
	{
	device_remove_file(dev, &attrs->in.dev_attr);
	device_remove_file(dev, &attrs->label.dev_attr);
	}

	/**
	* s3c_hwmon_probe - device probe entry.
	* @dev: The device being probed.
	*/
	static int s3c_hwmon_probe(struct platform_device *dev)
	{
	struct s3c_hwmon_pdata *pdata = dev_get_platdata(&dev->dev);
	struct s3c_hwmon *hwmon;
	int ret = 0;
	int i;

	if (!pdata) {
	dev_err(&dev->dev, "no platform data supplied\n");
	return -EINVAL;
	}

	hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL);
	if (hwmon == NULL)
	return -ENOMEM;

	platform_set_drvdata(dev, hwmon);

	mutex_init(&hwmon->lock);

	/* Register with the core ADC driver. */

	hwmon->client = s3c_adc_register(dev, NULL, NULL, 0);
	if (IS_ERR(hwmon->client)) {
	dev_err(&dev->dev, "cannot register adc\n");
	return PTR_ERR(hwmon->client);
	}

	/* add attributes for our adc devices. */

	ret = s3c_hwmon_add_raw(&dev->dev);
	if (ret)
	goto err_registered;

	/* register with the hwmon core */

	hwmon->hwmon_dev = hwmon_device_register(&dev->dev);
	if (IS_ERR(hwmon->hwmon_dev)) {
	dev_err(&dev->dev, "error registering with hwmon\n");
	ret = PTR_ERR(hwmon->hwmon_dev);
	goto err_raw_attribute;
	}

	for (i = 0; i < ARRAY_SIZE(pdata->in); i++) {
	struct s3c_hwmon_chcfg *cfg = pdata->in[i];

	if (!cfg)
	continue;

	if (cfg->mult >= 0x10000)
	dev_warn(&dev->dev,
	"channel %d multiplier too large\n",
	i);

	if (cfg->div == 0) {
	dev_err(&dev->dev, "channel %d divider zero\n", i);
	continue;
	}

	ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i],
	&hwmon->attrs[i], i);
	if (ret) {
	dev_err(&dev->dev,
	"error creating channel %d\n", i);

	for (i--; i >= 0; i--)
	s3c_hwmon_remove_attr(&dev->dev,
	&hwmon->attrs[i]);

	goto err_hwmon_register;
	}
	}

	return 0;

	err_hwmon_register:
	hwmon_device_unregister(hwmon->hwmon_dev);

	err_raw_attribute:
	s3c_hwmon_remove_raw(&dev->dev);

	err_registered:
	s3c_adc_release(hwmon->client);

	return ret;
	}

	static int s3c_hwmon_remove(struct platform_device *dev)
	{
	struct s3c_hwmon *hwmon = platform_get_drvdata(dev);
	int i;

	s3c_hwmon_remove_raw(&dev->dev);

	for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++)
	s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]);

	hwmon_device_unregister(hwmon->hwmon_dev);
	s3c_adc_release(hwmon->client);

	return 0;
	}

	static struct platform_driver s3c_hwmon_driver = {
	.driver = {
	.name = "s3c-hwmon",
	},
	.probe = s3c_hwmon_probe,
	.remove = s3c_hwmon_remove,
	};

	module_platform_driver(s3c_hwmon_driver);

	MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
	MODULE_DESCRIPTION("S3C ADC HWMon driver");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:s3c-hwmon");