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 * Chris Verges <kg4ysn@gmail.com> 12 * 13 * This software program is licensed subject to the GNU General Public License 14 * (GPL).Version 2,June 1991, available at 15 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html 16 */ 17 18 #include <linux/module.h> 19 #include <linux/init.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 /* 0x0190, byte-swapped */ 39 #define DRVNAME "lm73" 40 #define LM73_TEMP_MIN (-256000 / 250) 41 #define LM73_TEMP_MAX (255750 / 250) 42 43 #define LM73_CTRL_RES_SHIFT 5 44 #define LM73_CTRL_RES_MASK (BIT(5) | BIT(6)) 45 #define LM73_CTRL_TO_MASK BIT(7) 46 47 #define LM73_CTRL_HI_SHIFT 2 48 #define LM73_CTRL_LO_SHIFT 1 49 50 static const unsigned short lm73_convrates[] = { 51 14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */ 52 28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */ 53 56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */ 54 112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */ 55 }; 56 57 struct lm73_data { 58 struct i2c_client *client; 59 struct mutex lock; 60 u8 ctrl; /* control register value */ 61 }; 62 63 /*-----------------------------------------------------------------------*/ 64 65 static ssize_t temp_store(struct device *dev, struct device_attribute *da, 66 const char *buf, size_t count) 67 { 68 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 69 struct lm73_data *data = dev_get_drvdata(dev); 70 long temp; 71 short value; 72 s32 err; 73 74 int status = kstrtol(buf, 10, &temp); 75 if (status < 0) 76 return status; 77 78 /* Write value */ 79 value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5; 80 err = i2c_smbus_write_word_swapped(data->client, attr->index, value); 81 return (err < 0) ? err : count; 82 } 83 84 static ssize_t temp_show(struct device *dev, struct device_attribute *da, 85 char *buf) 86 { 87 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 88 struct lm73_data *data = dev_get_drvdata(dev); 89 int temp; 90 91 s32 err = i2c_smbus_read_word_swapped(data->client, attr->index); 92 if (err < 0) 93 return err; 94 95 /* use integer division instead of equivalent right shift to 96 guarantee arithmetic shift and preserve the sign */ 97 temp = (((s16) err) * 250) / 32; 98 return scnprintf(buf, PAGE_SIZE, "%d\n", temp); 99 } 100 101 static ssize_t convrate_store(struct device *dev, struct device_attribute *da, 102 const char *buf, size_t count) 103 { 104 struct lm73_data *data = dev_get_drvdata(dev); 105 unsigned long convrate; 106 s32 err; 107 int res = 0; 108 109 err = kstrtoul(buf, 10, &convrate); 110 if (err < 0) 111 return err; 112 113 /* 114 * Convert the desired conversion rate into register bits. 115 * res is already initialized, and everything past the second-to-last 116 * value in the array is treated as belonging to the last value 117 * in the array. 118 */ 119 while (res < (ARRAY_SIZE(lm73_convrates) - 1) && 120 convrate > lm73_convrates[res]) 121 res++; 122 123 mutex_lock(&data->lock); 124 data->ctrl &= LM73_CTRL_TO_MASK; 125 data->ctrl |= res << LM73_CTRL_RES_SHIFT; 126 err = i2c_smbus_write_byte_data(data->client, LM73_REG_CTRL, 127 data->ctrl); 128 mutex_unlock(&data->lock); 129 130 if (err < 0) 131 return err; 132 133 return count; 134 } 135 136 static ssize_t convrate_show(struct device *dev, struct device_attribute *da, 137 char *buf) 138 { 139 struct lm73_data *data = dev_get_drvdata(dev); 140 int res; 141 142 res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT; 143 return scnprintf(buf, PAGE_SIZE, "%hu\n", lm73_convrates[res]); 144 } 145 146 static ssize_t maxmin_alarm_show(struct device *dev, 147 struct device_attribute *da, char *buf) 148 { 149 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 150 struct lm73_data *data = dev_get_drvdata(dev); 151 s32 ctrl; 152 153 mutex_lock(&data->lock); 154 ctrl = i2c_smbus_read_byte_data(data->client, LM73_REG_CTRL); 155 if (ctrl < 0) 156 goto abort; 157 data->ctrl = ctrl; 158 mutex_unlock(&data->lock); 159 160 return scnprintf(buf, PAGE_SIZE, "%d\n", (ctrl >> attr->index) & 1); 161 162 abort: 163 mutex_unlock(&data->lock); 164 return ctrl; 165 } 166 167 /*-----------------------------------------------------------------------*/ 168 169 /* sysfs attributes for hwmon */ 170 171 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, LM73_REG_MAX); 172 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, LM73_REG_MIN); 173 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, LM73_REG_INPUT); 174 static SENSOR_DEVICE_ATTR_RW(update_interval, convrate, 0); 175 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, maxmin_alarm, 176 LM73_CTRL_HI_SHIFT); 177 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, maxmin_alarm, 178 LM73_CTRL_LO_SHIFT); 179 180 static struct attribute *lm73_attrs[] = { 181 &sensor_dev_attr_temp1_input.dev_attr.attr, 182 &sensor_dev_attr_temp1_max.dev_attr.attr, 183 &sensor_dev_attr_temp1_min.dev_attr.attr, 184 &sensor_dev_attr_update_interval.dev_attr.attr, 185 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 186 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 187 NULL 188 }; 189 ATTRIBUTE_GROUPS(lm73); 190 191 /*-----------------------------------------------------------------------*/ 192 193 /* device probe and removal */ 194 195 static int 196 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) 197 { 198 struct device *dev = &client->dev; 199 struct device *hwmon_dev; 200 struct lm73_data *data; 201 int ctrl; 202 203 data = devm_kzalloc(dev, sizeof(struct lm73_data), GFP_KERNEL); 204 if (!data) 205 return -ENOMEM; 206 207 data->client = client; 208 mutex_init(&data->lock); 209 210 ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL); 211 if (ctrl < 0) 212 return ctrl; 213 data->ctrl = ctrl; 214 215 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 216 data, lm73_groups); 217 if (IS_ERR(hwmon_dev)) 218 return PTR_ERR(hwmon_dev); 219 220 dev_info(dev, "sensor '%s'\n", client->name); 221 222 return 0; 223 } 224 225 static const struct i2c_device_id lm73_ids[] = { 226 { "lm73", 0 }, 227 { /* LIST END */ } 228 }; 229 MODULE_DEVICE_TABLE(i2c, lm73_ids); 230 231 /* Return 0 if detection is successful, -ENODEV otherwise */ 232 static int lm73_detect(struct i2c_client *new_client, 233 struct i2c_board_info *info) 234 { 235 struct i2c_adapter *adapter = new_client->adapter; 236 int id, ctrl, conf; 237 238 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 239 I2C_FUNC_SMBUS_WORD_DATA)) 240 return -ENODEV; 241 242 /* 243 * Do as much detection as possible with byte reads first, as word 244 * reads can confuse other devices. 245 */ 246 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 247 if (ctrl < 0 || (ctrl & 0x10)) 248 return -ENODEV; 249 250 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF); 251 if (conf < 0 || (conf & 0x0c)) 252 return -ENODEV; 253 254 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID); 255 if (id < 0 || id != (LM73_ID & 0xff)) 256 return -ENODEV; 257 258 /* Check device ID */ 259 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 260 if (id < 0 || id != LM73_ID) 261 return -ENODEV; 262 263 strlcpy(info->type, "lm73", I2C_NAME_SIZE); 264 265 return 0; 266 } 267 268 static struct i2c_driver lm73_driver = { 269 .class = I2C_CLASS_HWMON, 270 .driver = { 271 .name = "lm73", 272 }, 273 .probe = lm73_probe, 274 .id_table = lm73_ids, 275 .detect = lm73_detect, 276 .address_list = normal_i2c, 277 }; 278 279 module_i2c_driver(lm73_driver); 280 281 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 282 MODULE_DESCRIPTION("LM73 driver"); 283 MODULE_LICENSE("GPL"); 284