[deliverable/linux.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)
		return i2c_smbus_read_word_swapped(client, reg);
	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;
	int ret = kstrtol(buf, 10, &temp);

	if (ret < 0)
		return ret;

	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,
};

module_i2c_driver(ad7414_driver);

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	{
90f4102c JD	61	if (reg == AD7414_REG_TEMP)
	62	return i2c_smbus_read_word_swapped(client, reg);
	63	else
6c633c30 SM	64	return i2c_smbus_read_byte_data(client, reg);
	65	}
	66
	67	static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
	68	{
	69	return i2c_smbus_write_byte_data(client, reg, value);
	70	}
	71
d130d971	72	static struct ad7414_data ad7414_update_device(struct device dev)
6c633c30 SM	73	{
	74	struct i2c_client *client = to_i2c_client(dev);
	75	struct ad7414_data *data = i2c_get_clientdata(client);
	76
	77	mutex_lock(&data->lock);
	78
	79	if (time_after(jiffies, data->next_update) \|\| !data->valid) {
	80	int value, i;
	81
	82	dev_dbg(&client->dev, "starting ad7414 update\n");
	83
	84	value = ad7414_read(client, AD7414_REG_TEMP);
	85	if (value < 0)
	86	dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
	87	value);
	88	else
	89	data->temp_input = value;
	90
	91	for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
	92	value = ad7414_read(client, AD7414_REG_LIMIT[i]);
	93	if (value < 0)
	94	dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
	95	AD7414_REG_LIMIT[i], value);
	96	else
	97	data->temps[i] = value;
	98	}
	99
	100	data->next_update = jiffies + HZ + HZ / 2;
	101	data->valid = 1;
	102	}
	103
	104	mutex_unlock(&data->lock);
	105
	106	return data;
	107	}
	108
	109	static ssize_t show_temp_input(struct device *dev,
	110	struct device_attribute attr, char buf)
	111	{
	112	struct ad7414_data *data = ad7414_update_device(dev);
	113	return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
	114	}
	115	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
	116
	117	static ssize_t show_max_min(struct device dev, struct device_attribute attr,
	118	char *buf)
	119	{
	120	int index = to_sensor_dev_attr(attr)->index;
	121	struct ad7414_data *data = ad7414_update_device(dev);
	122	return sprintf(buf, "%d\n", data->temps[index] * 1000);
	123	}
	124
	125	static ssize_t set_max_min(struct device *dev,
	126	struct device_attribute *attr,
	127	const char *buf, size_t count)
	128	{
	129	struct i2c_client *client = to_i2c_client(dev);
	130	struct ad7414_data *data = i2c_get_clientdata(client);
	131	int index = to_sensor_dev_attr(attr)->index;
	132	u8 reg = AD7414_REG_LIMIT[index];
dcb7cb97 FM	133	long temp;
	134	int ret = kstrtol(buf, 10, &temp);
	135
	136	if (ret < 0)
	137	return ret;
6c633c30 SM	138
	139	temp = SENSORS_LIMIT(temp, -40000, 85000);
	140	temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
	141
	142	mutex_lock(&data->lock);
	143	data->temps[index] = temp;
	144	ad7414_write(client, reg, temp);
	145	mutex_unlock(&data->lock);
	146	return count;
	147	}
	148
	149	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	150	show_max_min, set_max_min, 0);
	151	static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
	152	show_max_min, set_max_min, 1);
	153
	154	static ssize_t show_alarm(struct device dev, struct device_attribute attr,
	155	char *buf)
	156	{
	157	int bitnr = to_sensor_dev_attr(attr)->index;
	158	struct ad7414_data *data = ad7414_update_device(dev);
	159	int value = (data->temp_input >> bitnr) & 1;
	160	return sprintf(buf, "%d\n", value);
	161	}
	162
	163	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
	164	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
	165
	166	static struct attribute *ad7414_attributes[] = {
	167	&sensor_dev_attr_temp1_input.dev_attr.attr,
	168	&sensor_dev_attr_temp1_max.dev_attr.attr,
	169	&sensor_dev_attr_temp1_min.dev_attr.attr,
	170	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	171	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	172	NULL
	173	};
	174
	175	static const struct attribute_group ad7414_group = {
	176	.attrs = ad7414_attributes,
	177	};
	178
	179	static int ad7414_probe(struct i2c_client *client,
	180	const struct i2c_device_id *dev_id)
	181	{
	182	struct ad7414_data *data;
	183	int conf;
f0030d87	184	int err;
6c633c30 SM	185
6c633c30 SM	186	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
f0030d87 AL	187	I2C_FUNC_SMBUS_READ_WORD_DATA)) {
f0030d87 AL	188	err = -EOPNOTSUPP;
6c633c30	189	goto exit;
f0030d87	190	}
6c633c30 SM	191
	192	data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
	193	if (!data) {
	194	err = -ENOMEM;
	195	goto exit;
	196	}
	197
	198	i2c_set_clientdata(client, data);
	199	mutex_init(&data->lock);
	200
	201	dev_info(&client->dev, "chip found\n");
	202
	203	/* Make sure the chip is powered up. */
	204	conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
	205	if (conf < 0)
	206	dev_warn(&client->dev,
	207	"ad7414_probe unable to read config register.\n");
	208	else {
	209	conf &= ~(1 << 7);
	210	i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
	211	}
	212
	213	/* Register sysfs hooks */
	214	err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
	215	if (err)
	216	goto exit_free;
	217
	218	data->hwmon_dev = hwmon_device_register(&client->dev);
	219	if (IS_ERR(data->hwmon_dev)) {
	220	err = PTR_ERR(data->hwmon_dev);
	221	goto exit_remove;
	222	}
	223
	224	return 0;
	225
	226	exit_remove:
	227	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	228	exit_free:
	229	kfree(data);
	230	exit:
	231	return err;
	232	}
	233
	234	static int __devexit ad7414_remove(struct i2c_client *client)
	235	{
	236	struct ad7414_data *data = i2c_get_clientdata(client);
	237
	238	hwmon_device_unregister(data->hwmon_dev);
	239	sysfs_remove_group(&client->dev.kobj, &ad7414_group);
	240	kfree(data);
	241	return 0;
	242	}
	243
	244	static const struct i2c_device_id ad7414_id[] = {
	245	{ "ad7414", 0 },
	246	{}
	247	};
6407deb5	248	MODULE_DEVICE_TABLE(i2c, ad7414_id);
6c633c30 SM	249
	250	static struct i2c_driver ad7414_driver = {
	251	.driver = {
	252	.name = "ad7414",
	253	},
	254	.probe = ad7414_probe,
	255	.remove = __devexit_p(ad7414_remove),
	256	.id_table = ad7414_id,
	257	};
	258
f0967eea	259	module_i2c_driver(ad7414_driver);
6c633c30 SM	260
	261	MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
	262	"Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
	263
	264	MODULE_DESCRIPTION("AD7414 driver");
	265	MODULE_LICENSE("GPL");