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 /* 0x0190, byte-swapped */ 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 s32 err; 53 54 int status = kstrtol(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 err = i2c_smbus_write_word_swapped(client, attr->index, value); 62 return (err < 0) ? err : 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 int temp; 71 72 s32 err = i2c_smbus_read_word_swapped(client, attr->index); 73 if (err < 0) 74 return err; 75 76 /* use integer division instead of equivalent right shift to 77 guarantee arithmetic shift and preserve the sign */ 78 temp = (((s16) err) * 250) / 32; 79 return scnprintf(buf, PAGE_SIZE, "%d\n", temp); 80 } 81 82 83 /*-----------------------------------------------------------------------*/ 84 85 /* sysfs attributes for hwmon */ 86 87 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 88 show_temp, set_temp, LM73_REG_MAX); 89 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 90 show_temp, set_temp, LM73_REG_MIN); 91 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, 92 show_temp, NULL, LM73_REG_INPUT); 93 94 95 static struct attribute *lm73_attributes[] = { 96 &sensor_dev_attr_temp1_input.dev_attr.attr, 97 &sensor_dev_attr_temp1_max.dev_attr.attr, 98 &sensor_dev_attr_temp1_min.dev_attr.attr, 99 100 NULL 101 }; 102 103 static const struct attribute_group lm73_group = { 104 .attrs = lm73_attributes, 105 }; 106 107 /*-----------------------------------------------------------------------*/ 108 109 /* device probe and removal */ 110 111 static int 112 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) 113 { 114 struct device *hwmon_dev; 115 int status; 116 117 /* Register sysfs hooks */ 118 status = sysfs_create_group(&client->dev.kobj, &lm73_group); 119 if (status) 120 return status; 121 122 hwmon_dev = hwmon_device_register(&client->dev); 123 if (IS_ERR(hwmon_dev)) { 124 status = PTR_ERR(hwmon_dev); 125 goto exit_remove; 126 } 127 i2c_set_clientdata(client, hwmon_dev); 128 129 dev_info(&client->dev, "%s: sensor '%s'\n", 130 dev_name(hwmon_dev), client->name); 131 132 return 0; 133 134 exit_remove: 135 sysfs_remove_group(&client->dev.kobj, &lm73_group); 136 return status; 137 } 138 139 static int lm73_remove(struct i2c_client *client) 140 { 141 struct device *hwmon_dev = i2c_get_clientdata(client); 142 143 hwmon_device_unregister(hwmon_dev); 144 sysfs_remove_group(&client->dev.kobj, &lm73_group); 145 return 0; 146 } 147 148 static const struct i2c_device_id lm73_ids[] = { 149 { "lm73", 0 }, 150 { /* LIST END */ } 151 }; 152 MODULE_DEVICE_TABLE(i2c, lm73_ids); 153 154 /* Return 0 if detection is successful, -ENODEV otherwise */ 155 static int lm73_detect(struct i2c_client *new_client, 156 struct i2c_board_info *info) 157 { 158 struct i2c_adapter *adapter = new_client->adapter; 159 int id, ctrl, conf; 160 161 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 162 I2C_FUNC_SMBUS_WORD_DATA)) 163 return -ENODEV; 164 165 /* 166 * Do as much detection as possible with byte reads first, as word 167 * reads can confuse other devices. 168 */ 169 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 170 if (ctrl < 0 || (ctrl & 0x10)) 171 return -ENODEV; 172 173 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF); 174 if (conf < 0 || (conf & 0x0c)) 175 return -ENODEV; 176 177 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID); 178 if (id < 0 || id != (LM73_ID & 0xff)) 179 return -ENODEV; 180 181 /* Check device ID */ 182 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 183 if (id < 0 || id != LM73_ID) 184 return -ENODEV; 185 186 strlcpy(info->type, "lm73", I2C_NAME_SIZE); 187 188 return 0; 189 } 190 191 static struct i2c_driver lm73_driver = { 192 .class = I2C_CLASS_HWMON, 193 .driver = { 194 .name = "lm73", 195 }, 196 .probe = lm73_probe, 197 .remove = lm73_remove, 198 .id_table = lm73_ids, 199 .detect = lm73_detect, 200 .address_list = normal_i2c, 201 }; 202 203 module_i2c_driver(lm73_driver); 204 205 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 206 MODULE_DESCRIPTION("LM73 driver"); 207 MODULE_LICENSE("GPL"); 208