Merge branch 'linus' into sched/core
[linux-3.10.git] / drivers / hwmon / lm73.c
1 /*
2  * LM73 Sensor driver
3  * Based on LM75
4  *
5  * Copyright (C) 2007, CenoSYS (www.cenosys.com).
6  * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
7  *
8  * Guillaume Ligneul <guillaume.ligneul@gmail.com>
9  * Adrien Demarez <adrien.demarez@bolloretelecom.eu>
10  * Jeremy Laine <jeremy.laine@bolloretelecom.eu>
11  *
12  * This software program is licensed subject to the GNU General Public License
13  * (GPL).Version 2,June 1991, available at
14  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
15  */
16
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/i2c.h>
20 #include <linux/hwmon.h>
21 #include <linux/hwmon-sysfs.h>
22 #include <linux/err.h>
23
24
25 /* Addresses scanned */
26 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
27                                         0x4d, 0x4e, I2C_CLIENT_END };
28
29 /* LM73 registers */
30 #define LM73_REG_INPUT          0x00
31 #define LM73_REG_CONF           0x01
32 #define LM73_REG_MAX            0x02
33 #define LM73_REG_MIN            0x03
34 #define LM73_REG_CTRL           0x04
35 #define LM73_REG_ID             0x07
36
37 #define LM73_ID                 0x9001 /* or 0x190 after a swab16() */
38 #define DRVNAME                 "lm73"
39 #define LM73_TEMP_MIN           (-40)
40 #define LM73_TEMP_MAX           150
41
42 /*-----------------------------------------------------------------------*/
43
44
45 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
46                         const char *buf, size_t count)
47 {
48         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
49         struct i2c_client *client = to_i2c_client(dev);
50         long temp;
51         short value;
52
53         int status = strict_strtol(buf, 10, &temp);
54         if (status < 0)
55                 return status;
56
57         /* Write value */
58         value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4),
59                 (LM73_TEMP_MAX*4)) << 5;
60         i2c_smbus_write_word_data(client, attr->index, swab16(value));
61         return count;
62 }
63
64 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
65                          char *buf)
66 {
67         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
68         struct i2c_client *client = to_i2c_client(dev);
69         /* use integer division instead of equivalent right shift to
70            guarantee arithmetic shift and preserve the sign */
71         int temp = ((s16) (swab16(i2c_smbus_read_word_data(client,
72                 attr->index)))*250) / 32;
73         return sprintf(buf, "%d\n", temp);
74 }
75
76
77 /*-----------------------------------------------------------------------*/
78
79 /* sysfs attributes for hwmon */
80
81 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
82                         show_temp, set_temp, LM73_REG_MAX);
83 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
84                         show_temp, set_temp, LM73_REG_MIN);
85 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
86                         show_temp, NULL, LM73_REG_INPUT);
87
88
89 static struct attribute *lm73_attributes[] = {
90         &sensor_dev_attr_temp1_input.dev_attr.attr,
91         &sensor_dev_attr_temp1_max.dev_attr.attr,
92         &sensor_dev_attr_temp1_min.dev_attr.attr,
93
94         NULL
95 };
96
97 static const struct attribute_group lm73_group = {
98         .attrs = lm73_attributes,
99 };
100
101 /*-----------------------------------------------------------------------*/
102
103 /* device probe and removal */
104
105 static int
106 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
107 {
108         struct device *hwmon_dev;
109         int status;
110
111         /* Register sysfs hooks */
112         status = sysfs_create_group(&client->dev.kobj, &lm73_group);
113         if (status)
114                 return status;
115
116         hwmon_dev = hwmon_device_register(&client->dev);
117         if (IS_ERR(hwmon_dev)) {
118                 status = PTR_ERR(hwmon_dev);
119                 goto exit_remove;
120         }
121         i2c_set_clientdata(client, hwmon_dev);
122
123         dev_info(&client->dev, "%s: sensor '%s'\n",
124                  dev_name(hwmon_dev), client->name);
125
126         return 0;
127
128 exit_remove:
129         sysfs_remove_group(&client->dev.kobj, &lm73_group);
130         return status;
131 }
132
133 static int lm73_remove(struct i2c_client *client)
134 {
135         struct device *hwmon_dev = i2c_get_clientdata(client);
136
137         hwmon_device_unregister(hwmon_dev);
138         sysfs_remove_group(&client->dev.kobj, &lm73_group);
139         i2c_set_clientdata(client, NULL);
140         return 0;
141 }
142
143 static const struct i2c_device_id lm73_ids[] = {
144         { "lm73", 0 },
145         { /* LIST END */ }
146 };
147 MODULE_DEVICE_TABLE(i2c, lm73_ids);
148
149 /* Return 0 if detection is successful, -ENODEV otherwise */
150 static int lm73_detect(struct i2c_client *new_client,
151                         struct i2c_board_info *info)
152 {
153         struct i2c_adapter *adapter = new_client->adapter;
154         u16 id;
155         u8 ctrl;
156
157         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
158                                         I2C_FUNC_SMBUS_WORD_DATA))
159                 return -ENODEV;
160
161         /* Check device ID */
162         id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
163         ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
164         if ((id != LM73_ID) || (ctrl & 0x10))
165                 return -ENODEV;
166
167         strlcpy(info->type, "lm73", I2C_NAME_SIZE);
168
169         return 0;
170 }
171
172 static struct i2c_driver lm73_driver = {
173         .class          = I2C_CLASS_HWMON,
174         .driver = {
175                 .name   = "lm73",
176         },
177         .probe          = lm73_probe,
178         .remove         = lm73_remove,
179         .id_table       = lm73_ids,
180         .detect         = lm73_detect,
181         .address_list   = normal_i2c,
182 };
183
184 /* module glue */
185
186 static int __init sensors_lm73_init(void)
187 {
188         return i2c_add_driver(&lm73_driver);
189 }
190
191 static void __exit sensors_lm73_exit(void)
192 {
193         i2c_del_driver(&lm73_driver);
194 }
195
196 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
197 MODULE_DESCRIPTION("LM73 driver");
198 MODULE_LICENSE("GPL");
199
200 module_init(sensors_lm73_init);
201 module_exit(sensors_lm73_exit);