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 return 0; 140 } 141 142 static const struct i2c_device_id lm73_ids[] = { 143 { "lm73", 0 }, 144 { /* LIST END */ } 145 }; 146 MODULE_DEVICE_TABLE(i2c, lm73_ids); 147 148 /* Return 0 if detection is successful, -ENODEV otherwise */ 149 static int lm73_detect(struct i2c_client *new_client, 150 struct i2c_board_info *info) 151 { 152 struct i2c_adapter *adapter = new_client->adapter; 153 u16 id; 154 u8 ctrl; 155 156 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 157 I2C_FUNC_SMBUS_WORD_DATA)) 158 return -ENODEV; 159 160 /* Check device ID */ 161 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 162 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 163 if ((id != LM73_ID) || (ctrl & 0x10)) 164 return -ENODEV; 165 166 strlcpy(info->type, "lm73", I2C_NAME_SIZE); 167 168 return 0; 169 } 170 171 static struct i2c_driver lm73_driver = { 172 .class = I2C_CLASS_HWMON, 173 .driver = { 174 .name = "lm73", 175 }, 176 .probe = lm73_probe, 177 .remove = lm73_remove, 178 .id_table = lm73_ids, 179 .detect = lm73_detect, 180 .address_list = normal_i2c, 181 }; 182 183 /* module glue */ 184 185 static int __init sensors_lm73_init(void) 186 { 187 return i2c_add_driver(&lm73_driver); 188 } 189 190 static void __exit sensors_lm73_exit(void) 191 { 192 i2c_del_driver(&lm73_driver); 193 } 194 195 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 196 MODULE_DESCRIPTION("LM73 driver"); 197 MODULE_LICENSE("GPL"); 198 199 module_init(sensors_lm73_init); 200 module_exit(sensors_lm73_exit); 201