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