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 (-256000 / 250) 40 #define LM73_TEMP_MAX (255750 / 250) 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 = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5; 60 err = i2c_smbus_write_word_swapped(client, attr->index, value); 61 return (err < 0) ? err : 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 int temp; 70 71 s32 err = i2c_smbus_read_word_swapped(client, attr->index); 72 if (err < 0) 73 return err; 74 75 /* use integer division instead of equivalent right shift to 76 guarantee arithmetic shift and preserve the sign */ 77 temp = (((s16) err) * 250) / 32; 78 return scnprintf(buf, PAGE_SIZE, "%d\n", temp); 79 } 80 81 82 /*-----------------------------------------------------------------------*/ 83 84 /* sysfs attributes for hwmon */ 85 86 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 87 show_temp, set_temp, LM73_REG_MAX); 88 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 89 show_temp, set_temp, LM73_REG_MIN); 90 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, 91 show_temp, NULL, LM73_REG_INPUT); 92 93 94 static struct attribute *lm73_attributes[] = { 95 &sensor_dev_attr_temp1_input.dev_attr.attr, 96 &sensor_dev_attr_temp1_max.dev_attr.attr, 97 &sensor_dev_attr_temp1_min.dev_attr.attr, 98 99 NULL 100 }; 101 102 static const struct attribute_group lm73_group = { 103 .attrs = lm73_attributes, 104 }; 105 106 /*-----------------------------------------------------------------------*/ 107 108 /* device probe and removal */ 109 110 static int 111 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) 112 { 113 struct device *hwmon_dev; 114 int status; 115 116 /* Register sysfs hooks */ 117 status = sysfs_create_group(&client->dev.kobj, &lm73_group); 118 if (status) 119 return status; 120 121 hwmon_dev = hwmon_device_register(&client->dev); 122 if (IS_ERR(hwmon_dev)) { 123 status = PTR_ERR(hwmon_dev); 124 goto exit_remove; 125 } 126 i2c_set_clientdata(client, hwmon_dev); 127 128 dev_info(&client->dev, "%s: sensor '%s'\n", 129 dev_name(hwmon_dev), client->name); 130 131 return 0; 132 133 exit_remove: 134 sysfs_remove_group(&client->dev.kobj, &lm73_group); 135 return status; 136 } 137 138 static int lm73_remove(struct i2c_client *client) 139 { 140 struct device *hwmon_dev = i2c_get_clientdata(client); 141 142 hwmon_device_unregister(hwmon_dev); 143 sysfs_remove_group(&client->dev.kobj, &lm73_group); 144 return 0; 145 } 146 147 static const struct i2c_device_id lm73_ids[] = { 148 { "lm73", 0 }, 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 int id, ctrl, conf; 159 160 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 161 I2C_FUNC_SMBUS_WORD_DATA)) 162 return -ENODEV; 163 164 /* 165 * Do as much detection as possible with byte reads first, as word 166 * reads can confuse other devices. 167 */ 168 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 169 if (ctrl < 0 || (ctrl & 0x10)) 170 return -ENODEV; 171 172 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF); 173 if (conf < 0 || (conf & 0x0c)) 174 return -ENODEV; 175 176 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID); 177 if (id < 0 || id != (LM73_ID & 0xff)) 178 return -ENODEV; 179 180 /* Check device ID */ 181 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 182 if (id < 0 || id != LM73_ID) 183 return -ENODEV; 184 185 strlcpy(info->type, "lm73", I2C_NAME_SIZE); 186 187 return 0; 188 } 189 190 static struct i2c_driver lm73_driver = { 191 .class = I2C_CLASS_HWMON, 192 .driver = { 193 .name = "lm73", 194 }, 195 .probe = lm73_probe, 196 .remove = lm73_remove, 197 .id_table = lm73_ids, 198 .detect = lm73_detect, 199 .address_list = normal_i2c, 200 }; 201 202 module_i2c_driver(lm73_driver); 203 204 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 205 MODULE_DESCRIPTION("LM73 driver"); 206 MODULE_LICENSE("GPL"); 207