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[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / hwmon / ad7414.c
blobdf29a7fff9e7af8b8bf6a88a0f56ab714df10144
1 /*
2 * An hwmon driver for the Analog Devices AD7414
4 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
6 * Copyright (c) 2008 PIKA Technologies
7 * Sean MacLennan <smaclennan@pikatech.com>
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)
13 * Based on ad7418.c
14 * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
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.
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>
30 #include <linux/slab.h>
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
39 static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
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)];
50 /* REG: (0.25C/bit, two's complement) << 6 */
51 static inline int ad7414_temp_from_reg(s16 reg)
53 /* use integer division instead of equivalent right shift to
54 * guarantee arithmetic shift and preserve the sign
56 return ((int)reg / 64) * 250;
59 static inline int ad7414_read(struct i2c_client *client, u8 reg)
61 if (reg == AD7414_REG_TEMP)
62 return i2c_smbus_read_word_swapped(client, reg);
63 else
64 return i2c_smbus_read_byte_data(client, reg);
67 static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
69 return i2c_smbus_write_byte_data(client, reg, value);
72 static struct ad7414_data *ad7414_update_device(struct device *dev)
74 struct i2c_client *client = to_i2c_client(dev);
75 struct ad7414_data *data = i2c_get_clientdata(client);
77 mutex_lock(&data->lock);
79 if (time_after(jiffies, data->next_update) || !data->valid) {
80 int value, i;
82 dev_dbg(&client->dev, "starting ad7414 update\n");
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;
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;
100 data->next_update = jiffies + HZ + HZ / 2;
101 data->valid = 1;
104 mutex_unlock(&data->lock);
106 return data;
109 static ssize_t show_temp_input(struct device *dev,
110 struct device_attribute *attr, char *buf)
112 struct ad7414_data *data = ad7414_update_device(dev);
113 return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
117 static ssize_t show_max_min(struct device *dev, struct device_attribute *attr,
118 char *buf)
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);
125 static ssize_t set_max_min(struct device *dev,
126 struct device_attribute *attr,
127 const char *buf, size_t count)
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];
133 long temp = simple_strtol(buf, NULL, 10);
135 temp = SENSORS_LIMIT(temp, -40000, 85000);
136 temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
138 mutex_lock(&data->lock);
139 data->temps[index] = temp;
140 ad7414_write(client, reg, temp);
141 mutex_unlock(&data->lock);
142 return count;
145 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
146 show_max_min, set_max_min, 0);
147 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
148 show_max_min, set_max_min, 1);
150 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
151 char *buf)
153 int bitnr = to_sensor_dev_attr(attr)->index;
154 struct ad7414_data *data = ad7414_update_device(dev);
155 int value = (data->temp_input >> bitnr) & 1;
156 return sprintf(buf, "%d\n", value);
159 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
160 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
162 static struct attribute *ad7414_attributes[] = {
163 &sensor_dev_attr_temp1_input.dev_attr.attr,
164 &sensor_dev_attr_temp1_max.dev_attr.attr,
165 &sensor_dev_attr_temp1_min.dev_attr.attr,
166 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
167 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
168 NULL
171 static const struct attribute_group ad7414_group = {
172 .attrs = ad7414_attributes,
175 static int ad7414_probe(struct i2c_client *client,
176 const struct i2c_device_id *dev_id)
178 struct ad7414_data *data;
179 int conf;
180 int err;
182 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
183 I2C_FUNC_SMBUS_READ_WORD_DATA)) {
184 err = -EOPNOTSUPP;
185 goto exit;
188 data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
189 if (!data) {
190 err = -ENOMEM;
191 goto exit;
194 i2c_set_clientdata(client, data);
195 mutex_init(&data->lock);
197 dev_info(&client->dev, "chip found\n");
199 /* Make sure the chip is powered up. */
200 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
201 if (conf < 0)
202 dev_warn(&client->dev,
203 "ad7414_probe unable to read config register.\n");
204 else {
205 conf &= ~(1 << 7);
206 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
209 /* Register sysfs hooks */
210 err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
211 if (err)
212 goto exit_free;
214 data->hwmon_dev = hwmon_device_register(&client->dev);
215 if (IS_ERR(data->hwmon_dev)) {
216 err = PTR_ERR(data->hwmon_dev);
217 goto exit_remove;
220 return 0;
222 exit_remove:
223 sysfs_remove_group(&client->dev.kobj, &ad7414_group);
224 exit_free:
225 kfree(data);
226 exit:
227 return err;
230 static int __devexit ad7414_remove(struct i2c_client *client)
232 struct ad7414_data *data = i2c_get_clientdata(client);
234 hwmon_device_unregister(data->hwmon_dev);
235 sysfs_remove_group(&client->dev.kobj, &ad7414_group);
236 kfree(data);
237 return 0;
240 static const struct i2c_device_id ad7414_id[] = {
241 { "ad7414", 0 },
244 MODULE_DEVICE_TABLE(i2c, ad7414_id);
246 static struct i2c_driver ad7414_driver = {
247 .driver = {
248 .name = "ad7414",
250 .probe = ad7414_probe,
251 .remove = __devexit_p(ad7414_remove),
252 .id_table = ad7414_id,
255 static int __init ad7414_init(void)
257 return i2c_add_driver(&ad7414_driver);
259 module_init(ad7414_init);
261 static void __exit ad7414_exit(void)
263 i2c_del_driver(&ad7414_driver);
265 module_exit(ad7414_exit);
267 MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
268 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
270 MODULE_DESCRIPTION("AD7414 driver");
271 MODULE_LICENSE("GPL");