1 /* 2 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com> 3 * 4 * The LM95245 is a sensor chip made by TI / National Semiconductor. 5 * It reports up to two temperatures (its own plus an external one). 6 * 7 * This driver is based on lm95241.c 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/err.h> 21 #include <linux/init.h> 22 #include <linux/hwmon.h> 23 #include <linux/i2c.h> 24 #include <linux/module.h> 25 #include <linux/mutex.h> 26 #include <linux/regmap.h> 27 #include <linux/slab.h> 28 29 static const unsigned short normal_i2c[] = { 30 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END }; 31 32 /* LM95245 registers */ 33 /* general registers */ 34 #define LM95245_REG_RW_CONFIG1 0x03 35 #define LM95245_REG_RW_CONVERS_RATE 0x04 36 #define LM95245_REG_W_ONE_SHOT 0x0F 37 38 /* diode configuration */ 39 #define LM95245_REG_RW_CONFIG2 0xBF 40 #define LM95245_REG_RW_REMOTE_OFFH 0x11 41 #define LM95245_REG_RW_REMOTE_OFFL 0x12 42 43 /* status registers */ 44 #define LM95245_REG_R_STATUS1 0x02 45 #define LM95245_REG_R_STATUS2 0x33 46 47 /* limit registers */ 48 #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07 49 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20 50 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19 51 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21 52 53 /* temperature signed */ 54 #define LM95245_REG_R_LOCAL_TEMPH_S 0x00 55 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30 56 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01 57 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10 58 /* temperature unsigned */ 59 #define LM95245_REG_R_REMOTE_TEMPH_U 0x31 60 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32 61 62 /* id registers */ 63 #define LM95245_REG_R_MAN_ID 0xFE 64 #define LM95245_REG_R_CHIP_ID 0xFF 65 66 /* LM95245 specific bitfields */ 67 #define CFG_STOP 0x40 68 #define CFG_REMOTE_TCRIT_MASK 0x10 69 #define CFG_REMOTE_OS_MASK 0x08 70 #define CFG_LOCAL_TCRIT_MASK 0x04 71 #define CFG_LOCAL_OS_MASK 0x02 72 73 #define CFG2_OS_A0 0x40 74 #define CFG2_DIODE_FAULT_OS 0x20 75 #define CFG2_DIODE_FAULT_TCRIT 0x10 76 #define CFG2_REMOTE_TT 0x08 77 #define CFG2_REMOTE_FILTER_DIS 0x00 78 #define CFG2_REMOTE_FILTER_EN 0x06 79 80 /* conversation rate in ms */ 81 #define RATE_CR0063 0x00 82 #define RATE_CR0364 0x01 83 #define RATE_CR1000 0x02 84 #define RATE_CR2500 0x03 85 86 #define STATUS1_ROS 0x10 87 #define STATUS1_DIODE_FAULT 0x04 88 #define STATUS1_RTCRIT 0x02 89 #define STATUS1_LOC 0x01 90 91 #define MANUFACTURER_ID 0x01 92 #define LM95235_REVISION 0xB1 93 #define LM95245_REVISION 0xB3 94 95 static const u8 lm95245_reg_address[] = { 96 LM95245_REG_R_LOCAL_TEMPH_S, 97 LM95245_REG_R_LOCAL_TEMPL_S, 98 LM95245_REG_R_REMOTE_TEMPH_S, 99 LM95245_REG_R_REMOTE_TEMPL_S, 100 LM95245_REG_R_REMOTE_TEMPH_U, 101 LM95245_REG_R_REMOTE_TEMPL_U, 102 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT, 103 LM95245_REG_RW_REMOTE_TCRIT_LIMIT, 104 LM95245_REG_RW_COMMON_HYSTERESIS, 105 LM95245_REG_R_STATUS1, 106 }; 107 108 /* Client data (each client gets its own) */ 109 struct lm95245_data { 110 struct regmap *regmap; 111 struct mutex update_lock; 112 int interval; /* in msecs */ 113 }; 114 115 /* Conversions */ 116 static int temp_from_reg_unsigned(u8 val_h, u8 val_l) 117 { 118 return val_h * 1000 + val_l * 1000 / 256; 119 } 120 121 static int temp_from_reg_signed(u8 val_h, u8 val_l) 122 { 123 if (val_h & 0x80) 124 return (val_h - 0x100) * 1000; 125 return temp_from_reg_unsigned(val_h, val_l); 126 } 127 128 static int lm95245_read_conversion_rate(struct lm95245_data *data) 129 { 130 unsigned int rate; 131 int ret; 132 133 ret = regmap_read(data->regmap, LM95245_REG_RW_CONVERS_RATE, &rate); 134 if (ret < 0) 135 return ret; 136 137 switch (rate) { 138 case RATE_CR0063: 139 data->interval = 63; 140 break; 141 case RATE_CR0364: 142 data->interval = 364; 143 break; 144 case RATE_CR1000: 145 data->interval = 1000; 146 break; 147 case RATE_CR2500: 148 default: 149 data->interval = 2500; 150 break; 151 } 152 return 0; 153 } 154 155 static int lm95245_set_conversion_rate(struct lm95245_data *data, long interval) 156 { 157 int ret, rate; 158 159 if (interval <= 63) { 160 interval = 63; 161 rate = RATE_CR0063; 162 } else if (interval <= 364) { 163 interval = 364; 164 rate = RATE_CR0364; 165 } else if (interval <= 1000) { 166 interval = 1000; 167 rate = RATE_CR1000; 168 } else { 169 interval = 2500; 170 rate = RATE_CR2500; 171 } 172 173 ret = regmap_write(data->regmap, LM95245_REG_RW_CONVERS_RATE, rate); 174 if (ret < 0) 175 return ret; 176 177 data->interval = interval; 178 return 0; 179 } 180 181 static int lm95245_read_temp(struct device *dev, u32 attr, int channel, 182 long *val) 183 { 184 struct lm95245_data *data = dev_get_drvdata(dev); 185 struct regmap *regmap = data->regmap; 186 int ret, regl, regh, regvall, regvalh; 187 188 switch (attr) { 189 case hwmon_temp_input: 190 regl = channel ? LM95245_REG_R_REMOTE_TEMPL_S : 191 LM95245_REG_R_LOCAL_TEMPL_S; 192 regh = channel ? LM95245_REG_R_REMOTE_TEMPH_S : 193 LM95245_REG_R_LOCAL_TEMPH_S; 194 ret = regmap_read(regmap, regl, ®vall); 195 if (ret < 0) 196 return ret; 197 ret = regmap_read(regmap, regh, ®valh); 198 if (ret < 0) 199 return ret; 200 /* 201 * Local temp is always signed. 202 * Remote temp has both signed and unsigned data. 203 * Use signed calculation for remote if signed bit is set 204 * or if reported temperature is below signed limit. 205 */ 206 if (!channel || (regvalh & 0x80) || regvalh < 0x7f) { 207 *val = temp_from_reg_signed(regvalh, regvall); 208 return 0; 209 } 210 ret = regmap_read(regmap, LM95245_REG_R_REMOTE_TEMPL_U, 211 ®vall); 212 if (ret < 0) 213 return ret; 214 ret = regmap_read(regmap, LM95245_REG_R_REMOTE_TEMPH_U, 215 ®valh); 216 if (ret < 0) 217 return ret; 218 *val = temp_from_reg_unsigned(regvalh, regvall); 219 return 0; 220 case hwmon_temp_max: 221 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, 222 ®valh); 223 if (ret < 0) 224 return ret; 225 *val = regvalh * 1000; 226 return 0; 227 case hwmon_temp_crit: 228 regh = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 229 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 230 ret = regmap_read(regmap, regh, ®valh); 231 if (ret < 0) 232 return ret; 233 *val = regvalh * 1000; 234 return 0; 235 case hwmon_temp_max_hyst: 236 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, 237 ®valh); 238 if (ret < 0) 239 return ret; 240 ret = regmap_read(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 241 ®vall); 242 if (ret < 0) 243 return ret; 244 *val = (regvalh - regvall) * 1000; 245 return 0; 246 case hwmon_temp_crit_hyst: 247 regh = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 248 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 249 ret = regmap_read(regmap, regh, ®valh); 250 if (ret < 0) 251 return ret; 252 ret = regmap_read(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 253 ®vall); 254 if (ret < 0) 255 return ret; 256 *val = (regvalh - regvall) * 1000; 257 return 0; 258 case hwmon_temp_type: 259 ret = regmap_read(regmap, LM95245_REG_RW_CONFIG2, ®valh); 260 if (ret < 0) 261 return ret; 262 *val = (regvalh & CFG2_REMOTE_TT) ? 1 : 2; 263 return 0; 264 case hwmon_temp_offset: 265 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OFFL, 266 ®vall); 267 if (ret < 0) 268 return ret; 269 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OFFH, 270 ®valh); 271 if (ret < 0) 272 return ret; 273 *val = temp_from_reg_signed(regvalh, regvall); 274 return 0; 275 case hwmon_temp_max_alarm: 276 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 277 if (ret < 0) 278 return ret; 279 *val = !!(regvalh & STATUS1_ROS); 280 return 0; 281 case hwmon_temp_crit_alarm: 282 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 283 if (ret < 0) 284 return ret; 285 *val = !!(regvalh & (channel ? STATUS1_RTCRIT : STATUS1_LOC)); 286 return 0; 287 case hwmon_temp_fault: 288 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 289 if (ret < 0) 290 return ret; 291 *val = !!(regvalh & STATUS1_DIODE_FAULT); 292 return 0; 293 default: 294 return -EOPNOTSUPP; 295 } 296 } 297 298 static int lm95245_write_temp(struct device *dev, u32 attr, int channel, 299 long val) 300 { 301 struct lm95245_data *data = dev_get_drvdata(dev); 302 struct regmap *regmap = data->regmap; 303 unsigned int regval; 304 int ret, reg; 305 306 switch (attr) { 307 case hwmon_temp_max: 308 val = clamp_val(val / 1000, 0, 255); 309 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, val); 310 return ret; 311 case hwmon_temp_crit: 312 reg = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 313 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 314 val = clamp_val(val / 1000, 0, channel ? 255 : 127); 315 ret = regmap_write(regmap, reg, val); 316 return ret; 317 case hwmon_temp_crit_hyst: 318 mutex_lock(&data->update_lock); 319 ret = regmap_read(regmap, LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT, 320 ®val); 321 if (ret < 0) { 322 mutex_unlock(&data->update_lock); 323 return ret; 324 } 325 /* Clamp to reasonable range to prevent overflow */ 326 val = clamp_val(val, -1000000, 1000000); 327 val = regval - val / 1000; 328 val = clamp_val(val, 0, 31); 329 ret = regmap_write(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 330 val); 331 mutex_unlock(&data->update_lock); 332 return ret; 333 case hwmon_temp_offset: 334 val = clamp_val(val, -128000, 127875); 335 val = val * 256 / 1000; 336 mutex_lock(&data->update_lock); 337 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OFFL, 338 val & 0xe0); 339 if (ret < 0) { 340 mutex_unlock(&data->update_lock); 341 return ret; 342 } 343 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OFFH, 344 (val >> 8) & 0xff); 345 mutex_unlock(&data->update_lock); 346 return ret; 347 case hwmon_temp_type: 348 if (val != 1 && val != 2) 349 return -EINVAL; 350 ret = regmap_update_bits(regmap, LM95245_REG_RW_CONFIG2, 351 CFG2_REMOTE_TT, 352 val == 1 ? CFG2_REMOTE_TT : 0); 353 return ret; 354 default: 355 return -EOPNOTSUPP; 356 } 357 } 358 359 static int lm95245_read_chip(struct device *dev, u32 attr, int channel, 360 long *val) 361 { 362 struct lm95245_data *data = dev_get_drvdata(dev); 363 364 switch (attr) { 365 case hwmon_chip_update_interval: 366 *val = data->interval; 367 return 0; 368 default: 369 return -EOPNOTSUPP; 370 } 371 } 372 373 static int lm95245_write_chip(struct device *dev, u32 attr, int channel, 374 long val) 375 { 376 struct lm95245_data *data = dev_get_drvdata(dev); 377 int ret; 378 379 switch (attr) { 380 case hwmon_chip_update_interval: 381 mutex_lock(&data->update_lock); 382 ret = lm95245_set_conversion_rate(data, val); 383 mutex_unlock(&data->update_lock); 384 return ret; 385 default: 386 return -EOPNOTSUPP; 387 } 388 } 389 390 static int lm95245_read(struct device *dev, enum hwmon_sensor_types type, 391 u32 attr, int channel, long *val) 392 { 393 switch (type) { 394 case hwmon_chip: 395 return lm95245_read_chip(dev, attr, channel, val); 396 case hwmon_temp: 397 return lm95245_read_temp(dev, attr, channel, val); 398 default: 399 return -EOPNOTSUPP; 400 } 401 } 402 403 static int lm95245_write(struct device *dev, enum hwmon_sensor_types type, 404 u32 attr, int channel, long val) 405 { 406 switch (type) { 407 case hwmon_chip: 408 return lm95245_write_chip(dev, attr, channel, val); 409 case hwmon_temp: 410 return lm95245_write_temp(dev, attr, channel, val); 411 default: 412 return -EOPNOTSUPP; 413 } 414 } 415 416 static umode_t lm95245_temp_is_visible(const void *data, u32 attr, int channel) 417 { 418 switch (attr) { 419 case hwmon_temp_input: 420 case hwmon_temp_max_alarm: 421 case hwmon_temp_max_hyst: 422 case hwmon_temp_crit_alarm: 423 case hwmon_temp_fault: 424 return S_IRUGO; 425 case hwmon_temp_type: 426 case hwmon_temp_max: 427 case hwmon_temp_crit: 428 case hwmon_temp_offset: 429 return S_IRUGO | S_IWUSR; 430 case hwmon_temp_crit_hyst: 431 return (channel == 0) ? S_IRUGO | S_IWUSR : S_IRUGO; 432 default: 433 return 0; 434 } 435 } 436 437 static umode_t lm95245_is_visible(const void *data, 438 enum hwmon_sensor_types type, 439 u32 attr, int channel) 440 { 441 switch (type) { 442 case hwmon_chip: 443 switch (attr) { 444 case hwmon_chip_update_interval: 445 return S_IRUGO | S_IWUSR; 446 default: 447 return 0; 448 } 449 case hwmon_temp: 450 return lm95245_temp_is_visible(data, attr, channel); 451 default: 452 return 0; 453 } 454 } 455 456 /* Return 0 if detection is successful, -ENODEV otherwise */ 457 static int lm95245_detect(struct i2c_client *new_client, 458 struct i2c_board_info *info) 459 { 460 struct i2c_adapter *adapter = new_client->adapter; 461 int address = new_client->addr; 462 const char *name; 463 int rev, id; 464 465 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 466 return -ENODEV; 467 468 id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID); 469 if (id != MANUFACTURER_ID) 470 return -ENODEV; 471 472 rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID); 473 switch (rev) { 474 case LM95235_REVISION: 475 if (address != 0x18 && address != 0x29 && address != 0x4c) 476 return -ENODEV; 477 name = "lm95235"; 478 break; 479 case LM95245_REVISION: 480 name = "lm95245"; 481 break; 482 default: 483 return -ENODEV; 484 } 485 486 strlcpy(info->type, name, I2C_NAME_SIZE); 487 return 0; 488 } 489 490 static int lm95245_init_client(struct lm95245_data *data) 491 { 492 int ret; 493 494 ret = lm95245_read_conversion_rate(data); 495 if (ret < 0) 496 return ret; 497 498 return regmap_update_bits(data->regmap, LM95245_REG_RW_CONFIG1, 499 CFG_STOP, 0); 500 } 501 502 static bool lm95245_is_writeable_reg(struct device *dev, unsigned int reg) 503 { 504 switch (reg) { 505 case LM95245_REG_RW_CONFIG1: 506 case LM95245_REG_RW_CONVERS_RATE: 507 case LM95245_REG_W_ONE_SHOT: 508 case LM95245_REG_RW_CONFIG2: 509 case LM95245_REG_RW_REMOTE_OFFH: 510 case LM95245_REG_RW_REMOTE_OFFL: 511 case LM95245_REG_RW_REMOTE_OS_LIMIT: 512 case LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT: 513 case LM95245_REG_RW_REMOTE_TCRIT_LIMIT: 514 case LM95245_REG_RW_COMMON_HYSTERESIS: 515 return true; 516 default: 517 return false; 518 } 519 } 520 521 static bool lm95245_is_volatile_reg(struct device *dev, unsigned int reg) 522 { 523 switch (reg) { 524 case LM95245_REG_R_STATUS1: 525 case LM95245_REG_R_STATUS2: 526 case LM95245_REG_R_LOCAL_TEMPH_S: 527 case LM95245_REG_R_LOCAL_TEMPL_S: 528 case LM95245_REG_R_REMOTE_TEMPH_S: 529 case LM95245_REG_R_REMOTE_TEMPL_S: 530 case LM95245_REG_R_REMOTE_TEMPH_U: 531 case LM95245_REG_R_REMOTE_TEMPL_U: 532 return true; 533 default: 534 return false; 535 } 536 } 537 538 static const struct regmap_config lm95245_regmap_config = { 539 .reg_bits = 8, 540 .val_bits = 8, 541 .writeable_reg = lm95245_is_writeable_reg, 542 .volatile_reg = lm95245_is_volatile_reg, 543 .cache_type = REGCACHE_RBTREE, 544 .use_single_read = true, 545 .use_single_write = true, 546 }; 547 548 static const u32 lm95245_chip_config[] = { 549 HWMON_C_UPDATE_INTERVAL, 550 0 551 }; 552 553 static const struct hwmon_channel_info lm95245_chip = { 554 .type = hwmon_chip, 555 .config = lm95245_chip_config, 556 }; 557 558 static const u32 lm95245_temp_config[] = { 559 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_CRIT_ALARM, 560 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST | HWMON_T_CRIT | 561 HWMON_T_CRIT_HYST | HWMON_T_FAULT | HWMON_T_MAX_ALARM | 562 HWMON_T_CRIT_ALARM | HWMON_T_TYPE | HWMON_T_OFFSET, 563 0 564 }; 565 566 static const struct hwmon_channel_info lm95245_temp = { 567 .type = hwmon_temp, 568 .config = lm95245_temp_config, 569 }; 570 571 static const struct hwmon_channel_info *lm95245_info[] = { 572 &lm95245_chip, 573 &lm95245_temp, 574 NULL 575 }; 576 577 static const struct hwmon_ops lm95245_hwmon_ops = { 578 .is_visible = lm95245_is_visible, 579 .read = lm95245_read, 580 .write = lm95245_write, 581 }; 582 583 static const struct hwmon_chip_info lm95245_chip_info = { 584 .ops = &lm95245_hwmon_ops, 585 .info = lm95245_info, 586 }; 587 588 static int lm95245_probe(struct i2c_client *client, 589 const struct i2c_device_id *id) 590 { 591 struct device *dev = &client->dev; 592 struct lm95245_data *data; 593 struct device *hwmon_dev; 594 int ret; 595 596 data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL); 597 if (!data) 598 return -ENOMEM; 599 600 data->regmap = devm_regmap_init_i2c(client, &lm95245_regmap_config); 601 if (IS_ERR(data->regmap)) 602 return PTR_ERR(data->regmap); 603 604 mutex_init(&data->update_lock); 605 606 /* Initialize the LM95245 chip */ 607 ret = lm95245_init_client(data); 608 if (ret < 0) 609 return ret; 610 611 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 612 data, 613 &lm95245_chip_info, 614 NULL); 615 return PTR_ERR_OR_ZERO(hwmon_dev); 616 } 617 618 /* Driver data (common to all clients) */ 619 static const struct i2c_device_id lm95245_id[] = { 620 { "lm95235", 0 }, 621 { "lm95245", 0 }, 622 { } 623 }; 624 MODULE_DEVICE_TABLE(i2c, lm95245_id); 625 626 static const struct of_device_id lm95245_of_match[] = { 627 { .compatible = "national,lm95235" }, 628 { .compatible = "national,lm95245" }, 629 { }, 630 }; 631 MODULE_DEVICE_TABLE(of, lm95245_of_match); 632 633 static struct i2c_driver lm95245_driver = { 634 .class = I2C_CLASS_HWMON, 635 .driver = { 636 .name = "lm95245", 637 .of_match_table = of_match_ptr(lm95245_of_match), 638 }, 639 .probe = lm95245_probe, 640 .id_table = lm95245_id, 641 .detect = lm95245_detect, 642 .address_list = normal_i2c, 643 }; 644 645 module_i2c_driver(lm95245_driver); 646 647 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 648 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver"); 649 MODULE_LICENSE("GPL"); 650