1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com> 4 * 5 * The LM95245 is a sensor chip made by TI / National Semiconductor. 6 * It reports up to two temperatures (its own plus an external one). 7 * 8 * This driver is based on lm95241.c 9 */ 10 11 #include <linux/err.h> 12 #include <linux/init.h> 13 #include <linux/hwmon.h> 14 #include <linux/i2c.h> 15 #include <linux/module.h> 16 #include <linux/mutex.h> 17 #include <linux/regmap.h> 18 #include <linux/slab.h> 19 20 static const unsigned short normal_i2c[] = { 21 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END }; 22 23 /* LM95245 registers */ 24 /* general registers */ 25 #define LM95245_REG_RW_CONFIG1 0x03 26 #define LM95245_REG_RW_CONVERS_RATE 0x04 27 #define LM95245_REG_W_ONE_SHOT 0x0F 28 29 /* diode configuration */ 30 #define LM95245_REG_RW_CONFIG2 0xBF 31 #define LM95245_REG_RW_REMOTE_OFFH 0x11 32 #define LM95245_REG_RW_REMOTE_OFFL 0x12 33 34 /* status registers */ 35 #define LM95245_REG_R_STATUS1 0x02 36 #define LM95245_REG_R_STATUS2 0x33 37 38 /* limit registers */ 39 #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07 40 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20 41 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19 42 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21 43 44 /* temperature signed */ 45 #define LM95245_REG_R_LOCAL_TEMPH_S 0x00 46 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30 47 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01 48 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10 49 /* temperature unsigned */ 50 #define LM95245_REG_R_REMOTE_TEMPH_U 0x31 51 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32 52 53 /* id registers */ 54 #define LM95245_REG_R_MAN_ID 0xFE 55 #define LM95245_REG_R_CHIP_ID 0xFF 56 57 /* LM95245 specific bitfields */ 58 #define CFG_STOP 0x40 59 #define CFG_REMOTE_TCRIT_MASK 0x10 60 #define CFG_REMOTE_OS_MASK 0x08 61 #define CFG_LOCAL_TCRIT_MASK 0x04 62 #define CFG_LOCAL_OS_MASK 0x02 63 64 #define CFG2_OS_A0 0x40 65 #define CFG2_DIODE_FAULT_OS 0x20 66 #define CFG2_DIODE_FAULT_TCRIT 0x10 67 #define CFG2_REMOTE_TT 0x08 68 #define CFG2_REMOTE_FILTER_DIS 0x00 69 #define CFG2_REMOTE_FILTER_EN 0x06 70 71 /* conversation rate in ms */ 72 #define RATE_CR0063 0x00 73 #define RATE_CR0364 0x01 74 #define RATE_CR1000 0x02 75 #define RATE_CR2500 0x03 76 77 #define STATUS1_ROS 0x10 78 #define STATUS1_DIODE_FAULT 0x04 79 #define STATUS1_RTCRIT 0x02 80 #define STATUS1_LOC 0x01 81 82 #define MANUFACTURER_ID 0x01 83 #define LM95235_REVISION 0xB1 84 #define LM95245_REVISION 0xB3 85 86 /* Client data (each client gets its own) */ 87 struct lm95245_data { 88 struct regmap *regmap; 89 struct mutex update_lock; 90 int interval; /* in msecs */ 91 }; 92 93 /* Conversions */ 94 static int temp_from_reg_unsigned(u8 val_h, u8 val_l) 95 { 96 return val_h * 1000 + val_l * 1000 / 256; 97 } 98 99 static int temp_from_reg_signed(u8 val_h, u8 val_l) 100 { 101 if (val_h & 0x80) 102 return (val_h - 0x100) * 1000; 103 return temp_from_reg_unsigned(val_h, val_l); 104 } 105 106 static int lm95245_read_conversion_rate(struct lm95245_data *data) 107 { 108 unsigned int rate; 109 int ret; 110 111 ret = regmap_read(data->regmap, LM95245_REG_RW_CONVERS_RATE, &rate); 112 if (ret < 0) 113 return ret; 114 115 switch (rate) { 116 case RATE_CR0063: 117 data->interval = 63; 118 break; 119 case RATE_CR0364: 120 data->interval = 364; 121 break; 122 case RATE_CR1000: 123 data->interval = 1000; 124 break; 125 case RATE_CR2500: 126 default: 127 data->interval = 2500; 128 break; 129 } 130 return 0; 131 } 132 133 static int lm95245_set_conversion_rate(struct lm95245_data *data, long interval) 134 { 135 int ret, rate; 136 137 if (interval <= 63) { 138 interval = 63; 139 rate = RATE_CR0063; 140 } else if (interval <= 364) { 141 interval = 364; 142 rate = RATE_CR0364; 143 } else if (interval <= 1000) { 144 interval = 1000; 145 rate = RATE_CR1000; 146 } else { 147 interval = 2500; 148 rate = RATE_CR2500; 149 } 150 151 ret = regmap_write(data->regmap, LM95245_REG_RW_CONVERS_RATE, rate); 152 if (ret < 0) 153 return ret; 154 155 data->interval = interval; 156 return 0; 157 } 158 159 static int lm95245_read_temp(struct device *dev, u32 attr, int channel, 160 long *val) 161 { 162 struct lm95245_data *data = dev_get_drvdata(dev); 163 struct regmap *regmap = data->regmap; 164 int ret, regl, regh, regvall, regvalh; 165 166 switch (attr) { 167 case hwmon_temp_input: 168 regl = channel ? LM95245_REG_R_REMOTE_TEMPL_S : 169 LM95245_REG_R_LOCAL_TEMPL_S; 170 regh = channel ? LM95245_REG_R_REMOTE_TEMPH_S : 171 LM95245_REG_R_LOCAL_TEMPH_S; 172 ret = regmap_read(regmap, regl, ®vall); 173 if (ret < 0) 174 return ret; 175 ret = regmap_read(regmap, regh, ®valh); 176 if (ret < 0) 177 return ret; 178 /* 179 * Local temp is always signed. 180 * Remote temp has both signed and unsigned data. 181 * Use signed calculation for remote if signed bit is set 182 * or if reported temperature is below signed limit. 183 */ 184 if (!channel || (regvalh & 0x80) || regvalh < 0x7f) { 185 *val = temp_from_reg_signed(regvalh, regvall); 186 return 0; 187 } 188 ret = regmap_read(regmap, LM95245_REG_R_REMOTE_TEMPL_U, 189 ®vall); 190 if (ret < 0) 191 return ret; 192 ret = regmap_read(regmap, LM95245_REG_R_REMOTE_TEMPH_U, 193 ®valh); 194 if (ret < 0) 195 return ret; 196 *val = temp_from_reg_unsigned(regvalh, regvall); 197 return 0; 198 case hwmon_temp_max: 199 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, 200 ®valh); 201 if (ret < 0) 202 return ret; 203 *val = regvalh * 1000; 204 return 0; 205 case hwmon_temp_crit: 206 regh = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 207 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 208 ret = regmap_read(regmap, regh, ®valh); 209 if (ret < 0) 210 return ret; 211 *val = regvalh * 1000; 212 return 0; 213 case hwmon_temp_max_hyst: 214 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, 215 ®valh); 216 if (ret < 0) 217 return ret; 218 ret = regmap_read(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 219 ®vall); 220 if (ret < 0) 221 return ret; 222 *val = (regvalh - regvall) * 1000; 223 return 0; 224 case hwmon_temp_crit_hyst: 225 regh = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 226 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 227 ret = regmap_read(regmap, regh, ®valh); 228 if (ret < 0) 229 return ret; 230 ret = regmap_read(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 231 ®vall); 232 if (ret < 0) 233 return ret; 234 *val = (regvalh - regvall) * 1000; 235 return 0; 236 case hwmon_temp_type: 237 ret = regmap_read(regmap, LM95245_REG_RW_CONFIG2, ®valh); 238 if (ret < 0) 239 return ret; 240 *val = (regvalh & CFG2_REMOTE_TT) ? 1 : 2; 241 return 0; 242 case hwmon_temp_offset: 243 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OFFL, 244 ®vall); 245 if (ret < 0) 246 return ret; 247 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OFFH, 248 ®valh); 249 if (ret < 0) 250 return ret; 251 *val = temp_from_reg_signed(regvalh, regvall); 252 return 0; 253 case hwmon_temp_max_alarm: 254 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 255 if (ret < 0) 256 return ret; 257 *val = !!(regvalh & STATUS1_ROS); 258 return 0; 259 case hwmon_temp_crit_alarm: 260 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 261 if (ret < 0) 262 return ret; 263 *val = !!(regvalh & (channel ? STATUS1_RTCRIT : STATUS1_LOC)); 264 return 0; 265 case hwmon_temp_fault: 266 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®valh); 267 if (ret < 0) 268 return ret; 269 *val = !!(regvalh & STATUS1_DIODE_FAULT); 270 return 0; 271 default: 272 return -EOPNOTSUPP; 273 } 274 } 275 276 static int lm95245_write_temp(struct device *dev, u32 attr, int channel, 277 long val) 278 { 279 struct lm95245_data *data = dev_get_drvdata(dev); 280 struct regmap *regmap = data->regmap; 281 unsigned int regval; 282 int ret, reg; 283 284 switch (attr) { 285 case hwmon_temp_max: 286 val = clamp_val(val / 1000, 0, 255); 287 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, val); 288 return ret; 289 case hwmon_temp_crit: 290 reg = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT : 291 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT; 292 val = clamp_val(val / 1000, 0, channel ? 255 : 127); 293 ret = regmap_write(regmap, reg, val); 294 return ret; 295 case hwmon_temp_crit_hyst: 296 mutex_lock(&data->update_lock); 297 ret = regmap_read(regmap, LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT, 298 ®val); 299 if (ret < 0) { 300 mutex_unlock(&data->update_lock); 301 return ret; 302 } 303 /* Clamp to reasonable range to prevent overflow */ 304 val = clamp_val(val, -1000000, 1000000); 305 val = regval - val / 1000; 306 val = clamp_val(val, 0, 31); 307 ret = regmap_write(regmap, LM95245_REG_RW_COMMON_HYSTERESIS, 308 val); 309 mutex_unlock(&data->update_lock); 310 return ret; 311 case hwmon_temp_offset: 312 val = clamp_val(val, -128000, 127875); 313 val = val * 256 / 1000; 314 mutex_lock(&data->update_lock); 315 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OFFL, 316 val & 0xe0); 317 if (ret < 0) { 318 mutex_unlock(&data->update_lock); 319 return ret; 320 } 321 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OFFH, 322 (val >> 8) & 0xff); 323 mutex_unlock(&data->update_lock); 324 return ret; 325 case hwmon_temp_type: 326 if (val != 1 && val != 2) 327 return -EINVAL; 328 ret = regmap_update_bits(regmap, LM95245_REG_RW_CONFIG2, 329 CFG2_REMOTE_TT, 330 val == 1 ? CFG2_REMOTE_TT : 0); 331 return ret; 332 default: 333 return -EOPNOTSUPP; 334 } 335 } 336 337 static int lm95245_read_chip(struct device *dev, u32 attr, int channel, 338 long *val) 339 { 340 struct lm95245_data *data = dev_get_drvdata(dev); 341 342 switch (attr) { 343 case hwmon_chip_update_interval: 344 *val = data->interval; 345 return 0; 346 default: 347 return -EOPNOTSUPP; 348 } 349 } 350 351 static int lm95245_write_chip(struct device *dev, u32 attr, int channel, 352 long val) 353 { 354 struct lm95245_data *data = dev_get_drvdata(dev); 355 int ret; 356 357 switch (attr) { 358 case hwmon_chip_update_interval: 359 mutex_lock(&data->update_lock); 360 ret = lm95245_set_conversion_rate(data, val); 361 mutex_unlock(&data->update_lock); 362 return ret; 363 default: 364 return -EOPNOTSUPP; 365 } 366 } 367 368 static int lm95245_read(struct device *dev, enum hwmon_sensor_types type, 369 u32 attr, int channel, long *val) 370 { 371 switch (type) { 372 case hwmon_chip: 373 return lm95245_read_chip(dev, attr, channel, val); 374 case hwmon_temp: 375 return lm95245_read_temp(dev, attr, channel, val); 376 default: 377 return -EOPNOTSUPP; 378 } 379 } 380 381 static int lm95245_write(struct device *dev, enum hwmon_sensor_types type, 382 u32 attr, int channel, long val) 383 { 384 switch (type) { 385 case hwmon_chip: 386 return lm95245_write_chip(dev, attr, channel, val); 387 case hwmon_temp: 388 return lm95245_write_temp(dev, attr, channel, val); 389 default: 390 return -EOPNOTSUPP; 391 } 392 } 393 394 static umode_t lm95245_temp_is_visible(const void *data, u32 attr, int channel) 395 { 396 switch (attr) { 397 case hwmon_temp_input: 398 case hwmon_temp_max_alarm: 399 case hwmon_temp_max_hyst: 400 case hwmon_temp_crit_alarm: 401 case hwmon_temp_fault: 402 return 0444; 403 case hwmon_temp_type: 404 case hwmon_temp_max: 405 case hwmon_temp_crit: 406 case hwmon_temp_offset: 407 return 0644; 408 case hwmon_temp_crit_hyst: 409 return (channel == 0) ? 0644 : 0444; 410 default: 411 return 0; 412 } 413 } 414 415 static umode_t lm95245_is_visible(const void *data, 416 enum hwmon_sensor_types type, 417 u32 attr, int channel) 418 { 419 switch (type) { 420 case hwmon_chip: 421 switch (attr) { 422 case hwmon_chip_update_interval: 423 return 0644; 424 default: 425 return 0; 426 } 427 case hwmon_temp: 428 return lm95245_temp_is_visible(data, attr, channel); 429 default: 430 return 0; 431 } 432 } 433 434 /* Return 0 if detection is successful, -ENODEV otherwise */ 435 static int lm95245_detect(struct i2c_client *new_client, 436 struct i2c_board_info *info) 437 { 438 struct i2c_adapter *adapter = new_client->adapter; 439 int address = new_client->addr; 440 const char *name; 441 int rev, id; 442 443 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 444 return -ENODEV; 445 446 id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID); 447 if (id != MANUFACTURER_ID) 448 return -ENODEV; 449 450 rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID); 451 switch (rev) { 452 case LM95235_REVISION: 453 if (address != 0x18 && address != 0x29 && address != 0x4c) 454 return -ENODEV; 455 name = "lm95235"; 456 break; 457 case LM95245_REVISION: 458 name = "lm95245"; 459 break; 460 default: 461 return -ENODEV; 462 } 463 464 strlcpy(info->type, name, I2C_NAME_SIZE); 465 return 0; 466 } 467 468 static int lm95245_init_client(struct lm95245_data *data) 469 { 470 int ret; 471 472 ret = lm95245_read_conversion_rate(data); 473 if (ret < 0) 474 return ret; 475 476 return regmap_update_bits(data->regmap, LM95245_REG_RW_CONFIG1, 477 CFG_STOP, 0); 478 } 479 480 static bool lm95245_is_writeable_reg(struct device *dev, unsigned int reg) 481 { 482 switch (reg) { 483 case LM95245_REG_RW_CONFIG1: 484 case LM95245_REG_RW_CONVERS_RATE: 485 case LM95245_REG_W_ONE_SHOT: 486 case LM95245_REG_RW_CONFIG2: 487 case LM95245_REG_RW_REMOTE_OFFH: 488 case LM95245_REG_RW_REMOTE_OFFL: 489 case LM95245_REG_RW_REMOTE_OS_LIMIT: 490 case LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT: 491 case LM95245_REG_RW_REMOTE_TCRIT_LIMIT: 492 case LM95245_REG_RW_COMMON_HYSTERESIS: 493 return true; 494 default: 495 return false; 496 } 497 } 498 499 static bool lm95245_is_volatile_reg(struct device *dev, unsigned int reg) 500 { 501 switch (reg) { 502 case LM95245_REG_R_STATUS1: 503 case LM95245_REG_R_STATUS2: 504 case LM95245_REG_R_LOCAL_TEMPH_S: 505 case LM95245_REG_R_LOCAL_TEMPL_S: 506 case LM95245_REG_R_REMOTE_TEMPH_S: 507 case LM95245_REG_R_REMOTE_TEMPL_S: 508 case LM95245_REG_R_REMOTE_TEMPH_U: 509 case LM95245_REG_R_REMOTE_TEMPL_U: 510 return true; 511 default: 512 return false; 513 } 514 } 515 516 static const struct regmap_config lm95245_regmap_config = { 517 .reg_bits = 8, 518 .val_bits = 8, 519 .writeable_reg = lm95245_is_writeable_reg, 520 .volatile_reg = lm95245_is_volatile_reg, 521 .cache_type = REGCACHE_RBTREE, 522 .use_single_read = true, 523 .use_single_write = true, 524 }; 525 526 static const struct hwmon_channel_info *lm95245_info[] = { 527 HWMON_CHANNEL_INFO(chip, 528 HWMON_C_UPDATE_INTERVAL), 529 HWMON_CHANNEL_INFO(temp, 530 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_HYST | 531 HWMON_T_CRIT_ALARM, 532 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST | 533 HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_FAULT | 534 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | 535 HWMON_T_TYPE | HWMON_T_OFFSET), 536 NULL 537 }; 538 539 static const struct hwmon_ops lm95245_hwmon_ops = { 540 .is_visible = lm95245_is_visible, 541 .read = lm95245_read, 542 .write = lm95245_write, 543 }; 544 545 static const struct hwmon_chip_info lm95245_chip_info = { 546 .ops = &lm95245_hwmon_ops, 547 .info = lm95245_info, 548 }; 549 550 static int lm95245_probe(struct i2c_client *client) 551 { 552 struct device *dev = &client->dev; 553 struct lm95245_data *data; 554 struct device *hwmon_dev; 555 int ret; 556 557 data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL); 558 if (!data) 559 return -ENOMEM; 560 561 data->regmap = devm_regmap_init_i2c(client, &lm95245_regmap_config); 562 if (IS_ERR(data->regmap)) 563 return PTR_ERR(data->regmap); 564 565 mutex_init(&data->update_lock); 566 567 /* Initialize the LM95245 chip */ 568 ret = lm95245_init_client(data); 569 if (ret < 0) 570 return ret; 571 572 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 573 data, 574 &lm95245_chip_info, 575 NULL); 576 return PTR_ERR_OR_ZERO(hwmon_dev); 577 } 578 579 /* Driver data (common to all clients) */ 580 static const struct i2c_device_id lm95245_id[] = { 581 { "lm95235", 0 }, 582 { "lm95245", 0 }, 583 { } 584 }; 585 MODULE_DEVICE_TABLE(i2c, lm95245_id); 586 587 static const struct of_device_id __maybe_unused lm95245_of_match[] = { 588 { .compatible = "national,lm95235" }, 589 { .compatible = "national,lm95245" }, 590 { }, 591 }; 592 MODULE_DEVICE_TABLE(of, lm95245_of_match); 593 594 static struct i2c_driver lm95245_driver = { 595 .class = I2C_CLASS_HWMON, 596 .driver = { 597 .name = "lm95245", 598 .of_match_table = of_match_ptr(lm95245_of_match), 599 }, 600 .probe_new = lm95245_probe, 601 .id_table = lm95245_id, 602 .detect = lm95245_detect, 603 .address_list = normal_i2c, 604 }; 605 606 module_i2c_driver(lm95245_driver); 607 608 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 609 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver"); 610 MODULE_LICENSE("GPL"); 611