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/slab.h>
  20 #include <linux/i2c.h>
  21 #include <linux/hwmon.h>
  22 #include <linux/hwmon-sysfs.h>
  23 #include <linux/err.h>
  24
  25
  26 /* Addresses scanned */
  27 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
  28                                         0x4d, 0x4e, I2C_CLIENT_END };
  29
  30 /* Insmod parameters */
  31 I2C_CLIENT_INSMOD_1(lm73);
  32
  33 /* LM73 registers */
  34 #define LM73_REG_INPUT          0x00
  35 #define LM73_REG_CONF           0x01
  36 #define LM73_REG_MAX            0x02
  37 #define LM73_REG_MIN            0x03
  38 #define LM73_REG_CTRL           0x04
  39 #define LM73_REG_ID             0x07
  40
  41 #define LM73_ID                 0x9001 /* or 0x190 after a swab16() */
  42 #define DRVNAME                 "lm73"
  43 #define LM73_TEMP_MIN           (-40)
  44 #define LM73_TEMP_MAX           150
  45
  46 /*-----------------------------------------------------------------------*/
  47
  48
  49 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
  50                         const char *buf, size_t count)
  51 {
  52         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  53         struct i2c_client *client = to_i2c_client(dev);
  54         long temp;
  55         short value;
  56
  57         int status = strict_strtol(buf, 10, &temp);
  58         if (status < 0)
  59                 return status;
  60
  61         /* Write value */
  62         value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4),
  63                 (LM73_TEMP_MAX*4)) << 5;
  64         i2c_smbus_write_word_data(client, attr->index, swab16(value));
  65         return count;
  66 }
  67
  68 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
  69                          char *buf)
  70 {
  71         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  72         struct i2c_client *client = to_i2c_client(dev);
  73         /* use integer division instead of equivalent right shift to
  74            guarantee arithmetic shift and preserve the sign */
  75         int temp = ((s16) (swab16(i2c_smbus_read_word_data(client,
  76                 attr->index)))*250) / 32;
  77         return sprintf(buf, "%d\n", temp);
  78 }
  79
  80
  81 /*-----------------------------------------------------------------------*/
  82
  83 /* sysfs attributes for hwmon */
  84
  85 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
  86                         show_temp, set_temp, LM73_REG_MAX);
  87 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
  88                         show_temp, set_temp, LM73_REG_MIN);
  89 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
  90                         show_temp, NULL, LM73_REG_INPUT);
  91
  92
  93 static struct attribute *lm73_attributes[] = {
  94         &sensor_dev_attr_temp1_input.dev_attr.attr,
  95         &sensor_dev_attr_temp1_max.dev_attr.attr,
  96         &sensor_dev_attr_temp1_min.dev_attr.attr,
  97
  98         NULL
  99 };
 100
 101 static const struct attribute_group lm73_group = {
 102         .attrs = lm73_attributes,
 103 };
 104
 105 /*-----------------------------------------------------------------------*/
 106
 107 /* device probe and removal */
 108
 109 static int
 110 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
 111 {
 112         struct device *hwmon_dev;
 113         int status;
 114
 115         /* Register sysfs hooks */
 116         status = sysfs_create_group(&client->dev.kobj, &lm73_group);
 117         if (status)
 118                 return status;
 119
 120         hwmon_dev = hwmon_device_register(&client->dev);
 121         if (IS_ERR(hwmon_dev)) {
 122                 status = PTR_ERR(hwmon_dev);
 123                 goto exit_remove;
 124         }
 125         i2c_set_clientdata(client, hwmon_dev);
 126
 127         dev_info(&client->dev, "%s: sensor '%s'\n",
 128                  dev_name(hwmon_dev), client->name);
 129
 130         return 0;
 131
 132 exit_remove:
 133         sysfs_remove_group(&client->dev.kobj, &lm73_group);
 134         return status;
 135 }
 136
 137 static int lm73_remove(struct i2c_client *client)
 138 {
 139         struct device *hwmon_dev = i2c_get_clientdata(client);
 140
 141         hwmon_device_unregister(hwmon_dev);
 142         sysfs_remove_group(&client->dev.kobj, &lm73_group);
 143         i2c_set_clientdata(client, NULL);
 144         return 0;
 145 }
 146
 147 static const struct i2c_device_id lm73_ids[] = {
 148         { "lm73", lm73 },
 149         { /* LIST END */ }
 150 };
 151 MODULE_DEVICE_TABLE(i2c, lm73_ids);
 152
 153 /* Return 0 if detection is successful, -ENODEV otherwise */
 154 static int lm73_detect(struct i2c_client *new_client,
 155                         struct i2c_board_info *info)
 156 {
 157         struct i2c_adapter *adapter = new_client->adapter;
 158         u16 id;
 159         u8 ctrl;
 160
 161         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 162                                         I2C_FUNC_SMBUS_WORD_DATA))
 163                 return -ENODEV;
 164
 165         /* Check device ID */
 166         id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
 167         ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
 168         if ((id != LM73_ID) || (ctrl & 0x10))
 169                 return -ENODEV;
 170
 171         strlcpy(info->type, "lm73", I2C_NAME_SIZE);
 172
 173         return 0;
 174 }
 175
 176 static struct i2c_driver lm73_driver = {
 177         .class          = I2C_CLASS_HWMON,
 178         .driver = {
 179                 .name   = "lm73",
 180         },
 181         .probe          = lm73_probe,
 182         .remove         = lm73_remove,
 183         .id_table       = lm73_ids,
 184         .detect         = lm73_detect,
 185         .address_list   = normal_i2c,
 186 };
 187
 188 /* module glue */
 189
 190 static int __init sensors_lm73_init(void)
 191 {
 192         return i2c_add_driver(&lm73_driver);
 193 }
 194
 195 static void __exit sensors_lm73_exit(void)
 196 {
 197         i2c_del_driver(&lm73_driver);
 198 }
 199
 200 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
 201 MODULE_DESCRIPTION("LM73 driver");
 202 MODULE_LICENSE("GPL");
 203
 204 module_init(sensors_lm73_init);
 205 module_exit(sensors_lm73_exit);