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