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Sean MacLennan6c633c32008-08-06 22:41:05 +02001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Sean MacLennan6c633c32008-08-06 22:41:05 +020031
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
39static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
40
41struct 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 */
51static 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
59static 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
68static 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
Adrian Bunkd130d972008-09-20 10:25:20 +020073static struct ad7414_data *ad7414_update_device(struct device *dev)
Sean MacLennan6c633c32008-08-06 22:41:05 +020074{
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
110static 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}
116static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
117
118static 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
126static 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
146static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
147 show_max_min, set_max_min, 0);
148static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
149 show_max_min, set_max_min, 1);
150
151static 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
160static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
161static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
162
163static 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
172static const struct attribute_group ad7414_group = {
173 .attrs = ad7414_attributes,
174};
175
176static int ad7414_probe(struct i2c_client *client,
177 const struct i2c_device_id *dev_id)
178{
179 struct ad7414_data *data;
180 int conf;
181 int err = 0;
182
183 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
184 I2C_FUNC_SMBUS_READ_WORD_DATA))
185 goto exit;
186
187 data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
188 if (!data) {
189 err = -ENOMEM;
190 goto exit;
191 }
192
193 i2c_set_clientdata(client, data);
194 mutex_init(&data->lock);
195
196 dev_info(&client->dev, "chip found\n");
197
198 /* Make sure the chip is powered up. */
199 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
200 if (conf < 0)
201 dev_warn(&client->dev,
202 "ad7414_probe unable to read config register.\n");
203 else {
204 conf &= ~(1 << 7);
205 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
206 }
207
208 /* Register sysfs hooks */
209 err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
210 if (err)
211 goto exit_free;
212
213 data->hwmon_dev = hwmon_device_register(&client->dev);
214 if (IS_ERR(data->hwmon_dev)) {
215 err = PTR_ERR(data->hwmon_dev);
216 goto exit_remove;
217 }
218
219 return 0;
220
221exit_remove:
222 sysfs_remove_group(&client->dev.kobj, &ad7414_group);
223exit_free:
224 kfree(data);
225exit:
226 return err;
227}
228
229static int __devexit ad7414_remove(struct i2c_client *client)
230{
231 struct ad7414_data *data = i2c_get_clientdata(client);
232
233 hwmon_device_unregister(data->hwmon_dev);
234 sysfs_remove_group(&client->dev.kobj, &ad7414_group);
235 kfree(data);
236 return 0;
237}
238
239static const struct i2c_device_id ad7414_id[] = {
240 { "ad7414", 0 },
241 {}
242};
243
244static struct i2c_driver ad7414_driver = {
245 .driver = {
246 .name = "ad7414",
247 },
248 .probe = ad7414_probe,
249 .remove = __devexit_p(ad7414_remove),
250 .id_table = ad7414_id,
251};
252
253static int __init ad7414_init(void)
254{
255 return i2c_add_driver(&ad7414_driver);
256}
257module_init(ad7414_init);
258
259static void __exit ad7414_exit(void)
260{
261 i2c_del_driver(&ad7414_driver);
262}
263module_exit(ad7414_exit);
264
265MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
266 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
267
268MODULE_DESCRIPTION("AD7414 driver");
269MODULE_LICENSE("GPL");