[net-next-2.6.git] / drivers / hwmon / ad7414.c

/*
 * 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 },
	{}
};

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");
Commit	Line	Data
6c633c30 SM	1	/*
	2	* An hwmon driver for the Analog Devices AD7414
	3	*
	4	* Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
	5	*
	6	* Copyright (c) 2008 PIKA Technologies
	7	* Sean MacLennan <smaclennan@pikatech.com>
	8	*
	9	* Copyright (c) 2008 Spansion Inc.
	10	* Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
	11	* (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
	12	*
	13	* Based on ad7418.c
	14	* Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
	15	*
	16	* This program is free software; you can redistribute it and/or modify
	17	* it under the terms of the GNU General Public License as published by
	18	* the Free Software Foundation; either version 2 of the License, or
	19	* (at your option) any later version.
	20	*/
	21
	22	#include <linux/module.h>
	23	#include <linux/jiffies.h>
	24	#include <linux/i2c.h>
	25	#include <linux/hwmon.h>
	26	#include <linux/hwmon-sysfs.h>
	27	#include <linux/err.h>
	28	#include <linux/mutex.h>
	29	#include <linux/sysfs.h>
5a0e3ad6	30	#include <linux/slab.h>
6c633c30 SM	31
	32
	33	/* AD7414 registers */
	34	#define AD7414_REG_TEMP 0x00
	35	#define AD7414_REG_CONF 0x01
	36	#define AD7414_REG_T_HIGH 0x02
	37	#define AD7414_REG_T_LOW 0x03
	38
	39	static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
	40
	41	struct ad7414_data {
	42	struct device *hwmon_dev;
	43	struct mutex lock; /* atomic read data updates */
	44	char valid; /* !=0 if following fields are valid */
	45	unsigned long next_update; /* In jiffies */
	46	s16 temp_input; /* Register values */
	47	s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
	48	};
	49
	50	/* REG: (0.25C/bit, two's complement) << 6 */
	51	static inline int ad7414_temp_from_reg(s16 reg)
	52	{
	53	/* use integer division instead of equivalent right shift to
	54	* guarantee arithmetic shift and preserve the sign
	55	*/
	56	return ((int)reg / 64) * 250;
	57	}
	58
	59	static inline int ad7414_read(struct i2c_client *client, u8 reg)
	60	{
	61	if (reg == AD7414_REG_TEMP) {
	62	int value = i2c_smbus_read_word_data(client, reg);
	63	return (value < 0) ? value : swab16(value);
	64	} else
	65	return i2c_smbus_read_byte_data(client, reg);
	66	}
	67
	68	static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
	69	{
	70	return i2c_smbus_write_byte_data(client, reg, value);
	71	}
	72
d130d971	73	static struct ad7414_data ad7414_update_device(struct device dev)
6c633c30 SM	74	{
	75	struct i2c_client *client = to_i2c_client(dev);
	76	struct ad7414_data *data = i2c_get_clientdata(client);
	77
	78	mutex_lock(&data->lock);
	79
	80	if (time_after(jiffies, data->next_update) \|\| !data->valid) {
	81	int value, i;
	82
	83	dev_dbg(&client->dev, "starting ad7414 update\n");
	84
	85	value = ad7414_read(client, AD7414_REG_TEMP);
	86	if (value < 0)
	87	dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
	88	value);
	89	else
	90	data->temp_input = value;
	91
	92	for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
	93	value = ad7414_read(client, AD7414_REG_LIMIT[i]);
	94	if (value < 0)
	95	dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
	96	AD7414_REG_LIMIT[i], value);
	97	else
	98	data->temps[i] = value;
	99	}
	100
	101	data->next_update = jiffies + HZ + HZ / 2;
	102	data->valid = 1;
	103	}
	104
	105	mutex_unlock(&data->lock);
	106
	107	return data;
	108	}
	109
	110	static ssize_t show_temp_input(struct device *dev,
	111	struct device_attribute attr, char buf)
	112	{
	113	struct ad7414_data *data = ad7414_update_device(dev);
	114	return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
	115	}
	116	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
	117
	118	static ssize_t show_max_min(struct device dev, struct device_attribute attr,
	119	char *buf)
	120	{
	121	int index = to_sensor_dev_attr(attr)->index;
	122	struct ad7414_data *data = ad7414_update_device(dev);
	123	return sprintf(buf, "%d\n", data->temps[index] * 1000);
	124	}
	125
	126	static ssize_t set_max_min(struct device *dev,
	127	struct device_attribute *attr,
	128	const char *buf, size_t count)
	129	{
	130	struct i2c_client *client = to_i2c_client(dev);
	131	struct ad7414_data *data = i2c_get_clientdata(client);
	132	int index = to_sensor_dev_attr(attr)->index;
	133	u8 reg = AD7414_REG_LIMIT[index];
	134	long temp = simple_strtol(buf, NULL, 10);
	135
	136	temp = SENSORS_LIMIT(temp, -40000, 85000);
	137	temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
138
139	mutex_lock(&data->lock);
140	data->temps[index] = temp;
141	ad7414_write(client, reg, temp);
142	mutex_unlock(&data->lock);
143	return count;
144	}
145
146	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
147	show_max_min, set_max_min, 0);
148	static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
149	show_max_min, set_max_min, 1);
150
151	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
152	char *buf)
153	{
154	int bitnr = to_sensor_dev_attr(attr)->index;
155	struct ad7414_data *data = ad7414_update_device(dev);
156	int value = (data->temp_input >> bitnr) & 1;
157	return sprintf(buf, "%d\n", value);
158	}
159
160	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
161	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
162
163	static struct attribute *ad7414_attributes[] = {
164	&sensor_dev_attr_temp1_input.dev_attr.attr,
165	&sensor_dev_attr_temp1_max.dev_attr.attr,
166	&sensor_dev_attr_temp1_min.dev_attr.attr,
167	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
168	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
169	NULL
170	};
171
172	static const struct attribute_group ad7414_group = {
173	.attrs = ad7414_attributes,
174	};
175
176	static int ad7414_probe(struct i2c_client *client,
177	const struct i2c_device_id *dev_id)
178	{
179	struct ad7414_data *data;
180	int conf;
f0030d87	181	int err;
6c633c30 SM	182
6c633c30 SM	183	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
f0030d87 AL	184	I2C_FUNC_SMBUS_READ_WORD_DATA)) {
f0030d87 AL	185	err = -EOPNOTSUPP;
6c633c30	186	goto exit;
f0030d87	187	}
6c633c30 SM	188
	189	data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
	190	if (!data) {
	191	err = -ENOMEM;
	192	goto exit;
	193	}
	194
	195	i2c_set_clientdata(client, data);
	196	mutex_init(&data->lock);
	197
	198	dev_info(&client->dev, "chip found\n");
	199
	200	/* Make sure the chip is powered up. */
	201	conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
	202	if (conf < 0)
	203	dev_warn(&client->dev,
	204	"ad7414_probe unable to read config register.\n");
	205	else {
	206	conf &= ~(1 << 7);
	207	i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
	208	}
	209
	210	/* Register sysfs hooks */
	211	err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
	212	if (err)
	213	goto exit_free;
	214
	215	data->hwmon_dev = hwmon_device_register(&client->dev);
	216	if (IS_ERR(data->hwmon_dev)) {
	217	err = PTR_ERR(data->hwmon_dev);
	218	goto exit_remove;
	219	}
	220
	221	return 0;
	222
	223	exit_remove:
	224	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	225	exit_free:
	226	kfree(data);
	227	exit:
	228	return err;
	229	}
	230
	231	static int __devexit ad7414_remove(struct i2c_client *client)
	232	{
	233	struct ad7414_data *data = i2c_get_clientdata(client);
	234
	235	hwmon_device_unregister(data->hwmon_dev);
	236	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	237	kfree(data);
	238	return 0;
	239	}
	240
	241	static const struct i2c_device_id ad7414_id[] = {
	242	{ "ad7414", 0 },
	243	{}
	244	};
	245
	246	static struct i2c_driver ad7414_driver = {
	247	.driver = {
	248	.name = "ad7414",
	249	},
	250	.probe = ad7414_probe,
	251	.remove = __devexit_p(ad7414_remove),
252	.id_table = ad7414_id,
253	};
254
255	static int __init ad7414_init(void)
256	{
257	return i2c_add_driver(&ad7414_driver);
258	}
259	module_init(ad7414_init);
260
261	static void __exit ad7414_exit(void)
262	{
263	i2c_del_driver(&ad7414_driver);
264	}
265	module_exit(ad7414_exit);
266
267	MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
268	"Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
269
270	MODULE_DESCRIPTION("AD7414 driver");
271	MODULE_LICENSE("GPL");