drivers/hwmon/ad7414.c - third_party/linux - Git at Google

 /*
  * An hwmon driver for the Analog Devices AD7414
  *
  * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
  *
  * Copyright (c) 2008 PIKA Technologies
  *   Sean MacLennan <smaclennan@pikatech.com>
  *
  * Copyright (c) 2008 Spansion Inc.
  *   Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
  *   (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
  *
  * Based on ad7418.c
  * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
  *
  * 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.
  */

 #include <linux/module.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
 #include <linux/slab.h>


 /* AD7414 registers */
 #define AD7414_REG_TEMP		0x00
 #define AD7414_REG_CONF		0x01
 #define AD7414_REG_T_HIGH	0x02
 #define AD7414_REG_T_LOW	0x03

 static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };

 struct ad7414_data {
 	struct device		*hwmon_dev;
 	struct mutex		lock;	/* atomic read data updates */
 	char			valid;	/* !=0 if following fields are valid */
 	unsigned long		next_update;	/* In jiffies */
 	s16			temp_input;	/* Register values */
 	s8			temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
 };

 /* REG: (0.25C/bit, two's complement) << 6 */
 static inline int ad7414_temp_from_reg(s16 reg)
 {
 	/* use integer division instead of equivalent right shift to
 	 * guarantee arithmetic shift and preserve the sign
 	 */
 	return ((int)reg / 64) * 250;
 }

 static inline int ad7414_read(struct i2c_client *client, u8 reg)
 {
 	if (reg == AD7414_REG_TEMP) {
 		int value = i2c_smbus_read_word_data(client, reg);
 		return (value < 0) ? value : swab16(value);
 	} else
 		return i2c_smbus_read_byte_data(client, reg);
 }

 static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
 {
 	return i2c_smbus_write_byte_data(client, reg, value);
 }

 static struct ad7414_data *ad7414_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct ad7414_data *data = i2c_get_clientdata(client);

 	mutex_lock(&data->lock);

 	if (time_after(jiffies, data->next_update) || !data->valid) {
 		int value, i;

 		dev_dbg(&client->dev, "starting ad7414 update\n");

 		value = ad7414_read(client, AD7414_REG_TEMP);
 		if (value < 0)
 			dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
 				value);
 		else
 			data->temp_input = value;

 		for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
 			value = ad7414_read(client, AD7414_REG_LIMIT[i]);
 			if (value < 0)
 				dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
 					AD7414_REG_LIMIT[i], value);
 			else
 				data->temps[i] = value;
 		}

 		data->next_update = jiffies + HZ + HZ / 2;
 		data->valid = 1;
 	}

 	mutex_unlock(&data->lock);

 	return data;
 }

 static ssize_t show_temp_input(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct ad7414_data *data = ad7414_update_device(dev);
 	return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
 }
 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);

 static ssize_t show_max_min(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
 	int index = to_sensor_dev_attr(attr)->index;
 	struct ad7414_data *data = ad7414_update_device(dev);
 	return sprintf(buf, "%d\n", data->temps[index] * 1000);
 }

 static ssize_t set_max_min(struct device *dev,
 			   struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct ad7414_data *data = i2c_get_clientdata(client);
 	int index = to_sensor_dev_attr(attr)->index;
 	u8 reg = AD7414_REG_LIMIT[index];
 	long temp = simple_strtol(buf, NULL, 10);

 	temp = SENSORS_LIMIT(temp, -40000, 85000);
 	temp = (temp + (temp < 0 ? -500 : 500)) / 1000;

 	mutex_lock(&data->lock);
 	data->temps[index] = temp;
 	ad7414_write(client, reg, temp);
 	mutex_unlock(&data->lock);
 	return count;
 }

 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 			  show_max_min, set_max_min, 0);
 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 			  show_max_min, set_max_min, 1);

 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
 	int bitnr = to_sensor_dev_attr(attr)->index;
 	struct ad7414_data *data = ad7414_update_device(dev);
 	int value = (data->temp_input >> bitnr) & 1;
 	return sprintf(buf, "%d\n", value);
 }

 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);

 static struct attribute *ad7414_attributes[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_min.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group ad7414_group = {
 	.attrs = ad7414_attributes,
 };

 static int ad7414_probe(struct i2c_client *client,
 			const struct i2c_device_id *dev_id)
 {
 	struct ad7414_data *data;
 	int conf;
 	int err;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 				     I2C_FUNC_SMBUS_READ_WORD_DATA)) {
 		err = -EOPNOTSUPP;
 		goto exit;
 	}

 	data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
 	if (!data) {
 		err = -ENOMEM;
 		goto exit;
 	}

 	i2c_set_clientdata(client, data);
 	mutex_init(&data->lock);

 	dev_info(&client->dev, "chip found\n");

 	/* Make sure the chip is powered up. */
 	conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
 	if (conf < 0)
 		dev_warn(&client->dev,
 			 "ad7414_probe unable to read config register.\n");
 	else {
 		conf &= ~(1 << 7);
 		i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
 	}

 	/* Register sysfs hooks */
 	err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
 	if (err)
 		goto exit_free;

 	data->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		err = PTR_ERR(data->hwmon_dev);
 		goto exit_remove;
 	}

 	return 0;

 exit_remove:
 	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
 exit_free:
 	kfree(data);
 exit:
 	return err;
 }

 static int __devexit ad7414_remove(struct i2c_client *client)
 {
 	struct ad7414_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
 	kfree(data);
 	return 0;
 }

 static const struct i2c_device_id ad7414_id[] = {
 	{ "ad7414", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ad7414_id);

 static struct i2c_driver ad7414_driver = {
 	.driver = {
 		.name	= "ad7414",
 	},
 	.probe	= ad7414_probe,
 	.remove	= __devexit_p(ad7414_remove),
 	.id_table = ad7414_id,
 };

 static int __init ad7414_init(void)
 {
 	return i2c_add_driver(&ad7414_driver);
 }
 module_init(ad7414_init);

 static void __exit ad7414_exit(void)
 {
 	i2c_del_driver(&ad7414_driver);
 }
 module_exit(ad7414_exit);

 MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
 	      "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");

 MODULE_DESCRIPTION("AD7414 driver");
 MODULE_LICENSE("GPL");
	/*
	* An hwmon driver for the Analog Devices AD7414
	*
	* Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
	*
	* Copyright (c) 2008 PIKA Technologies
	* Sean MacLennan <smaclennan@pikatech.com>
	*
	* Copyright (c) 2008 Spansion Inc.
	* Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
	* (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
	*
	* Based on ad7418.c
	* Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
	*
	* 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.
	*/

	#include <linux/module.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/hwmon.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/sysfs.h>
	#include <linux/slab.h>


	/* AD7414 registers */
	#define AD7414_REG_TEMP 0x00
	#define AD7414_REG_CONF 0x01
	#define AD7414_REG_T_HIGH 0x02
	#define AD7414_REG_T_LOW 0x03

	static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };

	struct ad7414_data {
	struct device *hwmon_dev;
	struct mutex lock; /* atomic read data updates */
	char valid; /* !=0 if following fields are valid */
	unsigned long next_update; /* In jiffies */
	s16 temp_input; /* Register values */
	s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
	};

	/* REG: (0.25C/bit, two's complement) << 6 */
	static inline int ad7414_temp_from_reg(s16 reg)
	{
	/* use integer division instead of equivalent right shift to
	* guarantee arithmetic shift and preserve the sign
	*/
	return ((int)reg / 64) * 250;
	}

	static inline int ad7414_read(struct i2c_client *client, u8 reg)
	{
	if (reg == AD7414_REG_TEMP) {
	int value = i2c_smbus_read_word_data(client, reg);
	return (value < 0) ? value : swab16(value);
	} else
	return i2c_smbus_read_byte_data(client, reg);
	}

	static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
	{
	return i2c_smbus_write_byte_data(client, reg, value);
	}

	static struct ad7414_data ad7414_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct ad7414_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->lock);

	if (time_after(jiffies, data->next_update) \|\| !data->valid) {
	int value, i;

	dev_dbg(&client->dev, "starting ad7414 update\n");

	value = ad7414_read(client, AD7414_REG_TEMP);
	if (value < 0)
	dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
	value);
	else
	data->temp_input = value;

	for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
	value = ad7414_read(client, AD7414_REG_LIMIT[i]);
	if (value < 0)
	dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
	AD7414_REG_LIMIT[i], value);
	else
	data->temps[i] = value;
	}

	data->next_update = jiffies + HZ + HZ / 2;
	data->valid = 1;
	}

	mutex_unlock(&data->lock);

	return data;
	}

	static ssize_t show_temp_input(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ad7414_data *data = ad7414_update_device(dev);
	return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
	}
	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);

	static ssize_t show_max_min(struct device dev, struct device_attribute attr,
	char *buf)
	{
	int index = to_sensor_dev_attr(attr)->index;
	struct ad7414_data *data = ad7414_update_device(dev);
	return sprintf(buf, "%d\n", data->temps[index] * 1000);
	}

	static ssize_t set_max_min(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct ad7414_data *data = i2c_get_clientdata(client);
	int index = to_sensor_dev_attr(attr)->index;
	u8 reg = AD7414_REG_LIMIT[index];
	long temp = simple_strtol(buf, NULL, 10);

	temp = SENSORS_LIMIT(temp, -40000, 85000);
	temp = (temp + (temp < 0 ? -500 : 500)) / 1000;

	mutex_lock(&data->lock);
	data->temps[index] = temp;
	ad7414_write(client, reg, temp);
	mutex_unlock(&data->lock);
	return count;
	}

	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	show_max_min, set_max_min, 0);
	static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
	show_max_min, set_max_min, 1);

	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
	char *buf)
	{
	int bitnr = to_sensor_dev_attr(attr)->index;
	struct ad7414_data *data = ad7414_update_device(dev);
	int value = (data->temp_input >> bitnr) & 1;
	return sprintf(buf, "%d\n", value);
	}

	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);

	static struct attribute *ad7414_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	NULL
	};

	static const struct attribute_group ad7414_group = {
	.attrs = ad7414_attributes,
	};

	static int ad7414_probe(struct i2c_client *client,
	const struct i2c_device_id *dev_id)
	{
	struct ad7414_data *data;
	int conf;
	int err;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	I2C_FUNC_SMBUS_READ_WORD_DATA)) {
	err = -EOPNOTSUPP;
	goto exit;
	}

	data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
	if (!data) {
	err = -ENOMEM;
	goto exit;
	}

	i2c_set_clientdata(client, data);
	mutex_init(&data->lock);

	dev_info(&client->dev, "chip found\n");

	/* Make sure the chip is powered up. */
	conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
	if (conf < 0)
	dev_warn(&client->dev,
	"ad7414_probe unable to read config register.\n");
	else {
	conf &= ~(1 << 7);
	i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
	}

	/* Register sysfs hooks */
	err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
	if (err)
	goto exit_free;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
	err = PTR_ERR(data->hwmon_dev);
	goto exit_remove;
	}

	return 0;

	exit_remove:
	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	exit_free:
	kfree(data);
	exit:
	return err;
	}

	static int __devexit ad7414_remove(struct i2c_client *client)
	{
	struct ad7414_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	kfree(data);
	return 0;
	}

	static const struct i2c_device_id ad7414_id[] = {
	{ "ad7414", 0 },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ad7414_id);

	static struct i2c_driver ad7414_driver = {
	.driver = {
	.name = "ad7414",
	},
	.probe = ad7414_probe,
	.remove = __devexit_p(ad7414_remove),
	.id_table = ad7414_id,
	};

	static int __init ad7414_init(void)
	{
	return i2c_add_driver(&ad7414_driver);
	}
	module_init(ad7414_init);

	static void __exit ad7414_exit(void)
	{
	i2c_del_driver(&ad7414_driver);
	}
	module_exit(ad7414_exit);

	MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
	"Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");

	MODULE_DESCRIPTION("AD7414 driver");
	MODULE_LICENSE("GPL");