1 /* 2 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com> 3 * 4 * The LM95241 is a sensor chip made by National Semiconductors. 5 * It reports up to three temperatures (its own plus up to two external ones). 6 * Complete datasheet can be obtained from National's website at: 7 * http://www.national.com/ds.cgi/LM/LM95241.pdf 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 */ 19 20 #include <linux/bitops.h> 21 #include <linux/err.h> 22 #include <linux/i2c.h> 23 #include <linux/init.h> 24 #include <linux/jiffies.h> 25 #include <linux/hwmon.h> 26 #include <linux/module.h> 27 #include <linux/mutex.h> 28 #include <linux/slab.h> 29 30 #define DEVNAME "lm95241" 31 32 static const unsigned short normal_i2c[] = { 33 0x19, 0x2a, 0x2b, I2C_CLIENT_END }; 34 35 /* LM95241 registers */ 36 #define LM95241_REG_R_MAN_ID 0xFE 37 #define LM95241_REG_R_CHIP_ID 0xFF 38 #define LM95241_REG_R_STATUS 0x02 39 #define LM95241_REG_RW_CONFIG 0x03 40 #define LM95241_REG_RW_REM_FILTER 0x06 41 #define LM95241_REG_RW_TRUTHERM 0x07 42 #define LM95241_REG_W_ONE_SHOT 0x0F 43 #define LM95241_REG_R_LOCAL_TEMPH 0x10 44 #define LM95241_REG_R_REMOTE1_TEMPH 0x11 45 #define LM95241_REG_R_REMOTE2_TEMPH 0x12 46 #define LM95241_REG_R_LOCAL_TEMPL 0x20 47 #define LM95241_REG_R_REMOTE1_TEMPL 0x21 48 #define LM95241_REG_R_REMOTE2_TEMPL 0x22 49 #define LM95241_REG_RW_REMOTE_MODEL 0x30 50 51 /* LM95241 specific bitfields */ 52 #define CFG_STOP BIT(6) 53 #define CFG_CR0076 0x00 54 #define CFG_CR0182 BIT(4) 55 #define CFG_CR1000 BIT(5) 56 #define CFG_CR2700 (BIT(4) | BIT(5)) 57 #define CFG_CRMASK (BIT(4) | BIT(5)) 58 #define R1MS_MASK BIT(0) 59 #define R2MS_MASK BIT(2) 60 #define R1DF_MASK BIT(1) 61 #define R2DF_MASK BIT(2) 62 #define R1FE_MASK BIT(0) 63 #define R2FE_MASK BIT(2) 64 #define R1DM BIT(0) 65 #define R2DM BIT(1) 66 #define TT1_SHIFT 0 67 #define TT2_SHIFT 4 68 #define TT_OFF 0 69 #define TT_ON 1 70 #define TT_MASK 7 71 #define NATSEMI_MAN_ID 0x01 72 #define LM95231_CHIP_ID 0xA1 73 #define LM95241_CHIP_ID 0xA4 74 75 static const u8 lm95241_reg_address[] = { 76 LM95241_REG_R_LOCAL_TEMPH, 77 LM95241_REG_R_LOCAL_TEMPL, 78 LM95241_REG_R_REMOTE1_TEMPH, 79 LM95241_REG_R_REMOTE1_TEMPL, 80 LM95241_REG_R_REMOTE2_TEMPH, 81 LM95241_REG_R_REMOTE2_TEMPL 82 }; 83 84 /* Client data (each client gets its own) */ 85 struct lm95241_data { 86 struct i2c_client *client; 87 struct mutex update_lock; 88 unsigned long last_updated; /* in jiffies */ 89 unsigned long interval; /* in milli-seconds */ 90 char valid; /* zero until following fields are valid */ 91 /* registers values */ 92 u8 temp[ARRAY_SIZE(lm95241_reg_address)]; 93 u8 status, config, model, trutherm; 94 }; 95 96 /* Conversions */ 97 static int temp_from_reg_signed(u8 val_h, u8 val_l) 98 { 99 s16 val_hl = (val_h << 8) | val_l; 100 return val_hl * 1000 / 256; 101 } 102 103 static int temp_from_reg_unsigned(u8 val_h, u8 val_l) 104 { 105 u16 val_hl = (val_h << 8) | val_l; 106 return val_hl * 1000 / 256; 107 } 108 109 static struct lm95241_data *lm95241_update_device(struct device *dev) 110 { 111 struct lm95241_data *data = dev_get_drvdata(dev); 112 struct i2c_client *client = data->client; 113 114 mutex_lock(&data->update_lock); 115 116 if (time_after(jiffies, data->last_updated 117 + msecs_to_jiffies(data->interval)) || 118 !data->valid) { 119 int i; 120 121 dev_dbg(dev, "Updating lm95241 data.\n"); 122 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++) 123 data->temp[i] 124 = i2c_smbus_read_byte_data(client, 125 lm95241_reg_address[i]); 126 127 data->status = i2c_smbus_read_byte_data(client, 128 LM95241_REG_R_STATUS); 129 data->last_updated = jiffies; 130 data->valid = 1; 131 } 132 133 mutex_unlock(&data->update_lock); 134 135 return data; 136 } 137 138 static int lm95241_read_chip(struct device *dev, u32 attr, int channel, 139 long *val) 140 { 141 struct lm95241_data *data = dev_get_drvdata(dev); 142 143 switch (attr) { 144 case hwmon_chip_update_interval: 145 *val = data->interval; 146 return 0; 147 default: 148 return -EOPNOTSUPP; 149 } 150 } 151 152 static int lm95241_read_temp(struct device *dev, u32 attr, int channel, 153 long *val) 154 { 155 struct lm95241_data *data = lm95241_update_device(dev); 156 157 switch (attr) { 158 case hwmon_temp_input: 159 if (!channel || (data->config & BIT(channel - 1))) 160 *val = temp_from_reg_signed(data->temp[channel * 2], 161 data->temp[channel * 2 + 1]); 162 else 163 *val = temp_from_reg_unsigned(data->temp[channel * 2], 164 data->temp[channel * 2 + 1]); 165 return 0; 166 case hwmon_temp_min: 167 if (channel == 1) 168 *val = (data->config & R1DF_MASK) ? -128000 : 0; 169 else 170 *val = (data->config & R2DF_MASK) ? -128000 : 0; 171 return 0; 172 case hwmon_temp_max: 173 if (channel == 1) 174 *val = (data->config & R1DF_MASK) ? 127875 : 255875; 175 else 176 *val = (data->config & R2DF_MASK) ? 127875 : 255875; 177 return 0; 178 case hwmon_temp_type: 179 if (channel == 1) 180 *val = (data->model & R1MS_MASK) ? 1 : 2; 181 else 182 *val = (data->model & R2MS_MASK) ? 1 : 2; 183 return 0; 184 case hwmon_temp_fault: 185 if (channel == 1) 186 *val = !!(data->status & R1DM); 187 else 188 *val = !!(data->status & R2DM); 189 return 0; 190 default: 191 return -EOPNOTSUPP; 192 } 193 } 194 195 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type, 196 u32 attr, int channel, long *val) 197 { 198 switch (type) { 199 case hwmon_chip: 200 return lm95241_read_chip(dev, attr, channel, val); 201 case hwmon_temp: 202 return lm95241_read_temp(dev, attr, channel, val); 203 default: 204 return -EOPNOTSUPP; 205 } 206 } 207 208 static int lm95241_write_chip(struct device *dev, u32 attr, int channel, 209 long val) 210 { 211 struct lm95241_data *data = dev_get_drvdata(dev); 212 int convrate; 213 u8 config; 214 int ret; 215 216 mutex_lock(&data->update_lock); 217 218 switch (attr) { 219 case hwmon_chip_update_interval: 220 config = data->config & ~CFG_CRMASK; 221 if (val < 130) { 222 convrate = 76; 223 config |= CFG_CR0076; 224 } else if (val < 590) { 225 convrate = 182; 226 config |= CFG_CR0182; 227 } else if (val < 1850) { 228 convrate = 1000; 229 config |= CFG_CR1000; 230 } else { 231 convrate = 2700; 232 config |= CFG_CR2700; 233 } 234 data->interval = convrate; 235 data->config = config; 236 ret = i2c_smbus_write_byte_data(data->client, 237 LM95241_REG_RW_CONFIG, config); 238 break; 239 default: 240 ret = -EOPNOTSUPP; 241 break; 242 } 243 mutex_unlock(&data->update_lock); 244 return ret; 245 } 246 247 static int lm95241_write_temp(struct device *dev, u32 attr, int channel, 248 long val) 249 { 250 struct lm95241_data *data = dev_get_drvdata(dev); 251 struct i2c_client *client = data->client; 252 int ret; 253 254 mutex_lock(&data->update_lock); 255 256 switch (attr) { 257 case hwmon_temp_min: 258 if (channel == 1) { 259 if (val < 0) 260 data->config |= R1DF_MASK; 261 else 262 data->config &= ~R1DF_MASK; 263 } else { 264 if (val < 0) 265 data->config |= R2DF_MASK; 266 else 267 data->config &= ~R2DF_MASK; 268 } 269 data->valid = 0; 270 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 271 data->config); 272 break; 273 case hwmon_temp_max: 274 if (channel == 1) { 275 if (val <= 127875) 276 data->config |= R1DF_MASK; 277 else 278 data->config &= ~R1DF_MASK; 279 } else { 280 if (val <= 127875) 281 data->config |= R2DF_MASK; 282 else 283 data->config &= ~R2DF_MASK; 284 } 285 data->valid = 0; 286 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, 287 data->config); 288 break; 289 case hwmon_temp_type: 290 if (val != 1 && val != 2) { 291 ret = -EINVAL; 292 break; 293 } 294 if (channel == 1) { 295 data->trutherm &= ~(TT_MASK << TT1_SHIFT); 296 if (val == 1) { 297 data->model |= R1MS_MASK; 298 data->trutherm |= (TT_ON << TT1_SHIFT); 299 } else { 300 data->model &= ~R1MS_MASK; 301 data->trutherm |= (TT_OFF << TT1_SHIFT); 302 } 303 } else { 304 data->trutherm &= ~(TT_MASK << TT2_SHIFT); 305 if (val == 1) { 306 data->model |= R2MS_MASK; 307 data->trutherm |= (TT_ON << TT2_SHIFT); 308 } else { 309 data->model &= ~R2MS_MASK; 310 data->trutherm |= (TT_OFF << TT2_SHIFT); 311 } 312 } 313 ret = i2c_smbus_write_byte_data(client, 314 LM95241_REG_RW_REMOTE_MODEL, 315 data->model); 316 if (ret < 0) 317 break; 318 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 319 data->trutherm); 320 break; 321 default: 322 ret = -EOPNOTSUPP; 323 break; 324 } 325 326 mutex_unlock(&data->update_lock); 327 328 return ret; 329 } 330 331 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type, 332 u32 attr, int channel, long val) 333 { 334 switch (type) { 335 case hwmon_chip: 336 return lm95241_write_chip(dev, attr, channel, val); 337 case hwmon_temp: 338 return lm95241_write_temp(dev, attr, channel, val); 339 default: 340 return -EOPNOTSUPP; 341 } 342 } 343 344 static umode_t lm95241_is_visible(const void *data, 345 enum hwmon_sensor_types type, 346 u32 attr, int channel) 347 { 348 switch (type) { 349 case hwmon_chip: 350 switch (attr) { 351 case hwmon_chip_update_interval: 352 return 0644; 353 } 354 break; 355 case hwmon_temp: 356 switch (attr) { 357 case hwmon_temp_input: 358 return 0444; 359 case hwmon_temp_fault: 360 return 0444; 361 case hwmon_temp_min: 362 case hwmon_temp_max: 363 case hwmon_temp_type: 364 return 0644; 365 } 366 break; 367 default: 368 break; 369 } 370 return 0; 371 } 372 373 /* Return 0 if detection is successful, -ENODEV otherwise */ 374 static int lm95241_detect(struct i2c_client *new_client, 375 struct i2c_board_info *info) 376 { 377 struct i2c_adapter *adapter = new_client->adapter; 378 const char *name; 379 int mfg_id, chip_id; 380 381 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 382 return -ENODEV; 383 384 mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID); 385 if (mfg_id != NATSEMI_MAN_ID) 386 return -ENODEV; 387 388 chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID); 389 switch (chip_id) { 390 case LM95231_CHIP_ID: 391 name = "lm95231"; 392 break; 393 case LM95241_CHIP_ID: 394 name = "lm95241"; 395 break; 396 default: 397 return -ENODEV; 398 } 399 400 /* Fill the i2c board info */ 401 strlcpy(info->type, name, I2C_NAME_SIZE); 402 return 0; 403 } 404 405 static void lm95241_init_client(struct i2c_client *client, 406 struct lm95241_data *data) 407 { 408 data->interval = 1000; 409 data->config = CFG_CR1000; 410 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT); 411 412 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config); 413 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER, 414 R1FE_MASK | R2FE_MASK); 415 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, 416 data->trutherm); 417 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, 418 data->model); 419 } 420 421 static const struct hwmon_channel_info *lm95241_info[] = { 422 HWMON_CHANNEL_INFO(chip, 423 HWMON_C_UPDATE_INTERVAL), 424 HWMON_CHANNEL_INFO(temp, 425 HWMON_T_INPUT, 426 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | 427 HWMON_T_TYPE | HWMON_T_FAULT, 428 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | 429 HWMON_T_TYPE | HWMON_T_FAULT), 430 NULL 431 }; 432 433 static const struct hwmon_ops lm95241_hwmon_ops = { 434 .is_visible = lm95241_is_visible, 435 .read = lm95241_read, 436 .write = lm95241_write, 437 }; 438 439 static const struct hwmon_chip_info lm95241_chip_info = { 440 .ops = &lm95241_hwmon_ops, 441 .info = lm95241_info, 442 }; 443 444 static int lm95241_probe(struct i2c_client *client, 445 const struct i2c_device_id *id) 446 { 447 struct device *dev = &client->dev; 448 struct lm95241_data *data; 449 struct device *hwmon_dev; 450 451 data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL); 452 if (!data) 453 return -ENOMEM; 454 455 data->client = client; 456 mutex_init(&data->update_lock); 457 458 /* Initialize the LM95241 chip */ 459 lm95241_init_client(client, data); 460 461 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 462 data, 463 &lm95241_chip_info, 464 NULL); 465 return PTR_ERR_OR_ZERO(hwmon_dev); 466 } 467 468 /* Driver data (common to all clients) */ 469 static const struct i2c_device_id lm95241_id[] = { 470 { "lm95231", 0 }, 471 { "lm95241", 0 }, 472 { } 473 }; 474 MODULE_DEVICE_TABLE(i2c, lm95241_id); 475 476 static struct i2c_driver lm95241_driver = { 477 .class = I2C_CLASS_HWMON, 478 .driver = { 479 .name = DEVNAME, 480 }, 481 .probe = lm95241_probe, 482 .id_table = lm95241_id, 483 .detect = lm95241_detect, 484 .address_list = normal_i2c, 485 }; 486 487 module_i2c_driver(lm95241_driver); 488 489 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>"); 490 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver"); 491 MODULE_LICENSE("GPL"); 492