1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Hardware monitoring driver for Maxim MAX6621 4 * 5 * Copyright (c) 2017 Mellanox Technologies. All rights reserved. 6 * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com> 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/hwmon.h> 11 #include <linux/hwmon-sysfs.h> 12 #include <linux/i2c.h> 13 #include <linux/init.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/regmap.h> 17 18 #define MAX6621_DRV_NAME "max6621" 19 #define MAX6621_TEMP_INPUT_REG_NUM 9 20 #define MAX6621_TEMP_INPUT_MIN -127000 21 #define MAX6621_TEMP_INPUT_MAX 128000 22 #define MAX6621_TEMP_ALERT_CHAN_SHIFT 1 23 24 #define MAX6621_TEMP_S0D0_REG 0x00 25 #define MAX6621_TEMP_S0D1_REG 0x01 26 #define MAX6621_TEMP_S1D0_REG 0x02 27 #define MAX6621_TEMP_S1D1_REG 0x03 28 #define MAX6621_TEMP_S2D0_REG 0x04 29 #define MAX6621_TEMP_S2D1_REG 0x05 30 #define MAX6621_TEMP_S3D0_REG 0x06 31 #define MAX6621_TEMP_S3D1_REG 0x07 32 #define MAX6621_TEMP_MAX_REG 0x08 33 #define MAX6621_TEMP_MAX_ADDR_REG 0x0a 34 #define MAX6621_TEMP_ALERT_CAUSE_REG 0x0b 35 #define MAX6621_CONFIG0_REG 0x0c 36 #define MAX6621_CONFIG1_REG 0x0d 37 #define MAX6621_CONFIG2_REG 0x0e 38 #define MAX6621_CONFIG3_REG 0x0f 39 #define MAX6621_TEMP_S0_ALERT_REG 0x10 40 #define MAX6621_TEMP_S1_ALERT_REG 0x11 41 #define MAX6621_TEMP_S2_ALERT_REG 0x12 42 #define MAX6621_TEMP_S3_ALERT_REG 0x13 43 #define MAX6621_CLEAR_ALERT_REG 0x15 44 #define MAX6621_REG_MAX (MAX6621_CLEAR_ALERT_REG + 1) 45 #define MAX6621_REG_TEMP_SHIFT 0x06 46 47 #define MAX6621_ENABLE_TEMP_ALERTS_BIT 4 48 #define MAX6621_ENABLE_I2C_CRC_BIT 5 49 #define MAX6621_ENABLE_ALTERNATE_DATA 6 50 #define MAX6621_ENABLE_LOCKUP_TO 7 51 #define MAX6621_ENABLE_S0D0_BIT 8 52 #define MAX6621_ENABLE_S3D1_BIT 15 53 #define MAX6621_ENABLE_TEMP_ALL GENMASK(MAX6621_ENABLE_S3D1_BIT, \ 54 MAX6621_ENABLE_S0D0_BIT) 55 #define MAX6621_POLL_DELAY_MASK 0x5 56 #define MAX6621_CONFIG0_INIT (MAX6621_ENABLE_TEMP_ALL | \ 57 BIT(MAX6621_ENABLE_LOCKUP_TO) | \ 58 BIT(MAX6621_ENABLE_I2C_CRC_BIT) | \ 59 MAX6621_POLL_DELAY_MASK) 60 #define MAX6621_PECI_BIT_TIME 0x2 61 #define MAX6621_PECI_RETRY_NUM 0x3 62 #define MAX6621_CONFIG1_INIT ((MAX6621_PECI_BIT_TIME << 8) | \ 63 MAX6621_PECI_RETRY_NUM) 64 65 /* Error codes */ 66 #define MAX6621_TRAN_FAILED 0x8100 /* 67 * PECI transaction failed for more 68 * than the configured number of 69 * consecutive retries. 70 */ 71 #define MAX6621_POOL_DIS 0x8101 /* 72 * Polling disabled for requested 73 * socket/domain. 74 */ 75 #define MAX6621_POOL_UNCOMPLETE 0x8102 /* 76 * First poll not yet completed for 77 * requested socket/domain (on 78 * startup). 79 */ 80 #define MAX6621_SD_DIS 0x8103 /* 81 * Read maximum temperature requested, 82 * but no sockets/domains enabled or 83 * all enabled sockets/domains have 84 * errors; or read maximum temperature 85 * address requested, but read maximum 86 * temperature was not called. 87 */ 88 #define MAX6621_ALERT_DIS 0x8104 /* 89 * Get alert socket/domain requested, 90 * but no alert active. 91 */ 92 #define MAX6621_PECI_ERR_MIN 0x8000 /* Intel spec PECI error min value. */ 93 #define MAX6621_PECI_ERR_MAX 0x80ff /* Intel spec PECI error max value. */ 94 95 static const u32 max6621_temp_regs[] = { 96 MAX6621_TEMP_MAX_REG, MAX6621_TEMP_S0D0_REG, MAX6621_TEMP_S1D0_REG, 97 MAX6621_TEMP_S2D0_REG, MAX6621_TEMP_S3D0_REG, MAX6621_TEMP_S0D1_REG, 98 MAX6621_TEMP_S1D1_REG, MAX6621_TEMP_S2D1_REG, MAX6621_TEMP_S3D1_REG, 99 }; 100 101 static const char *const max6621_temp_labels[] = { 102 "maximum", 103 "socket0_0", 104 "socket1_0", 105 "socket2_0", 106 "socket3_0", 107 "socket0_1", 108 "socket1_1", 109 "socket2_1", 110 "socket3_1", 111 }; 112 113 static const int max6621_temp_alert_chan2reg[] = { 114 MAX6621_TEMP_S0_ALERT_REG, 115 MAX6621_TEMP_S1_ALERT_REG, 116 MAX6621_TEMP_S2_ALERT_REG, 117 MAX6621_TEMP_S3_ALERT_REG, 118 }; 119 120 /** 121 * struct max6621_data - private data: 122 * 123 * @client: I2C client; 124 * @regmap: register map handle; 125 * @input_chan2reg: mapping from channel to register; 126 */ 127 struct max6621_data { 128 struct i2c_client *client; 129 struct regmap *regmap; 130 int input_chan2reg[MAX6621_TEMP_INPUT_REG_NUM + 1]; 131 }; 132 133 static long max6621_temp_mc2reg(long val) 134 { 135 return (val / 1000L) << MAX6621_REG_TEMP_SHIFT; 136 } 137 138 static umode_t 139 max6621_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, 140 int channel) 141 { 142 /* Skip channels which are not physically conncted. */ 143 if (((struct max6621_data *)data)->input_chan2reg[channel] < 0) 144 return 0; 145 146 switch (type) { 147 case hwmon_temp: 148 switch (attr) { 149 case hwmon_temp_input: 150 case hwmon_temp_label: 151 case hwmon_temp_crit_alarm: 152 return 0444; 153 case hwmon_temp_offset: 154 case hwmon_temp_crit: 155 return 0644; 156 default: 157 break; 158 } 159 break; 160 default: 161 break; 162 } 163 164 return 0; 165 } 166 167 static int max6621_verify_reg_data(struct device *dev, int regval) 168 { 169 if (regval >= MAX6621_PECI_ERR_MIN && 170 regval <= MAX6621_PECI_ERR_MAX) { 171 dev_dbg(dev, "PECI error code - err 0x%04x.\n", 172 regval); 173 174 return -EIO; 175 } 176 177 switch (regval) { 178 case MAX6621_TRAN_FAILED: 179 dev_dbg(dev, "PECI transaction failed - err 0x%04x.\n", 180 regval); 181 return -EIO; 182 case MAX6621_POOL_DIS: 183 dev_dbg(dev, "Polling disabled - err 0x%04x.\n", regval); 184 return -EOPNOTSUPP; 185 case MAX6621_POOL_UNCOMPLETE: 186 dev_dbg(dev, "First poll not completed on startup - err 0x%04x.\n", 187 regval); 188 return -EIO; 189 case MAX6621_SD_DIS: 190 dev_dbg(dev, "Resource is disabled - err 0x%04x.\n", regval); 191 return -EOPNOTSUPP; 192 case MAX6621_ALERT_DIS: 193 dev_dbg(dev, "No alert active - err 0x%04x.\n", regval); 194 return -EOPNOTSUPP; 195 default: 196 return 0; 197 } 198 } 199 200 static int 201 max6621_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, 202 int channel, long *val) 203 { 204 struct max6621_data *data = dev_get_drvdata(dev); 205 u32 regval; 206 int reg; 207 s8 temp; 208 int ret; 209 210 switch (type) { 211 case hwmon_temp: 212 switch (attr) { 213 case hwmon_temp_input: 214 reg = data->input_chan2reg[channel]; 215 ret = regmap_read(data->regmap, reg, ®val); 216 if (ret) 217 return ret; 218 219 ret = max6621_verify_reg_data(dev, regval); 220 if (ret) 221 return ret; 222 223 /* 224 * Bit MAX6621_REG_TEMP_SHIFT represents 1 degree step. 225 * The temperature is given in two's complement and 8 226 * bits is used for the register conversion. 227 */ 228 temp = (regval >> MAX6621_REG_TEMP_SHIFT); 229 *val = temp * 1000L; 230 231 break; 232 case hwmon_temp_offset: 233 ret = regmap_read(data->regmap, MAX6621_CONFIG2_REG, 234 ®val); 235 if (ret) 236 return ret; 237 238 ret = max6621_verify_reg_data(dev, regval); 239 if (ret) 240 return ret; 241 242 *val = (regval >> MAX6621_REG_TEMP_SHIFT) * 243 1000L; 244 245 break; 246 case hwmon_temp_crit: 247 channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT; 248 reg = max6621_temp_alert_chan2reg[channel]; 249 ret = regmap_read(data->regmap, reg, ®val); 250 if (ret) 251 return ret; 252 253 ret = max6621_verify_reg_data(dev, regval); 254 if (ret) 255 return ret; 256 257 *val = regval * 1000L; 258 259 break; 260 case hwmon_temp_crit_alarm: 261 /* 262 * Set val to zero to recover the case, when reading 263 * MAX6621_TEMP_ALERT_CAUSE_REG results in for example 264 * MAX6621_ALERT_DIS. Reading will return with error, 265 * but in such case alarm should be returned as 0. 266 */ 267 *val = 0; 268 ret = regmap_read(data->regmap, 269 MAX6621_TEMP_ALERT_CAUSE_REG, 270 ®val); 271 if (ret) 272 return ret; 273 274 ret = max6621_verify_reg_data(dev, regval); 275 if (ret) { 276 /* Do not report error if alert is disabled. */ 277 if (regval == MAX6621_ALERT_DIS) 278 return 0; 279 else 280 return ret; 281 } 282 283 /* 284 * Clear the alert automatically, using send-byte 285 * smbus protocol for clearing alert. 286 */ 287 if (regval) { 288 ret = i2c_smbus_write_byte(data->client, 289 MAX6621_CLEAR_ALERT_REG); 290 if (ret) 291 return ret; 292 } 293 294 *val = !!regval; 295 296 break; 297 default: 298 return -EOPNOTSUPP; 299 } 300 break; 301 302 default: 303 return -EOPNOTSUPP; 304 } 305 306 return 0; 307 } 308 309 static int 310 max6621_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, 311 int channel, long val) 312 { 313 struct max6621_data *data = dev_get_drvdata(dev); 314 u32 reg; 315 316 switch (type) { 317 case hwmon_temp: 318 switch (attr) { 319 case hwmon_temp_offset: 320 /* Clamp to allowed range to prevent overflow. */ 321 val = clamp_val(val, MAX6621_TEMP_INPUT_MIN, 322 MAX6621_TEMP_INPUT_MAX); 323 val = max6621_temp_mc2reg(val); 324 325 return regmap_write(data->regmap, 326 MAX6621_CONFIG2_REG, val); 327 case hwmon_temp_crit: 328 channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT; 329 reg = max6621_temp_alert_chan2reg[channel]; 330 /* Clamp to allowed range to prevent overflow. */ 331 val = clamp_val(val, MAX6621_TEMP_INPUT_MIN, 332 MAX6621_TEMP_INPUT_MAX); 333 val = val / 1000L; 334 335 return regmap_write(data->regmap, reg, val); 336 default: 337 return -EOPNOTSUPP; 338 } 339 break; 340 341 default: 342 return -EOPNOTSUPP; 343 } 344 345 return -EOPNOTSUPP; 346 } 347 348 static int 349 max6621_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr, 350 int channel, const char **str) 351 { 352 switch (type) { 353 case hwmon_temp: 354 switch (attr) { 355 case hwmon_temp_label: 356 *str = max6621_temp_labels[channel]; 357 return 0; 358 default: 359 return -EOPNOTSUPP; 360 } 361 break; 362 default: 363 return -EOPNOTSUPP; 364 } 365 366 return -EOPNOTSUPP; 367 } 368 369 static bool max6621_writeable_reg(struct device *dev, unsigned int reg) 370 { 371 switch (reg) { 372 case MAX6621_CONFIG0_REG: 373 case MAX6621_CONFIG1_REG: 374 case MAX6621_CONFIG2_REG: 375 case MAX6621_CONFIG3_REG: 376 case MAX6621_TEMP_S0_ALERT_REG: 377 case MAX6621_TEMP_S1_ALERT_REG: 378 case MAX6621_TEMP_S2_ALERT_REG: 379 case MAX6621_TEMP_S3_ALERT_REG: 380 case MAX6621_TEMP_ALERT_CAUSE_REG: 381 return true; 382 } 383 return false; 384 } 385 386 static bool max6621_readable_reg(struct device *dev, unsigned int reg) 387 { 388 switch (reg) { 389 case MAX6621_TEMP_S0D0_REG: 390 case MAX6621_TEMP_S0D1_REG: 391 case MAX6621_TEMP_S1D0_REG: 392 case MAX6621_TEMP_S1D1_REG: 393 case MAX6621_TEMP_S2D0_REG: 394 case MAX6621_TEMP_S2D1_REG: 395 case MAX6621_TEMP_S3D0_REG: 396 case MAX6621_TEMP_S3D1_REG: 397 case MAX6621_TEMP_MAX_REG: 398 case MAX6621_TEMP_MAX_ADDR_REG: 399 case MAX6621_CONFIG0_REG: 400 case MAX6621_CONFIG1_REG: 401 case MAX6621_CONFIG2_REG: 402 case MAX6621_CONFIG3_REG: 403 case MAX6621_TEMP_S0_ALERT_REG: 404 case MAX6621_TEMP_S1_ALERT_REG: 405 case MAX6621_TEMP_S2_ALERT_REG: 406 case MAX6621_TEMP_S3_ALERT_REG: 407 return true; 408 } 409 return false; 410 } 411 412 static bool max6621_volatile_reg(struct device *dev, unsigned int reg) 413 { 414 switch (reg) { 415 case MAX6621_TEMP_S0D0_REG: 416 case MAX6621_TEMP_S0D1_REG: 417 case MAX6621_TEMP_S1D0_REG: 418 case MAX6621_TEMP_S1D1_REG: 419 case MAX6621_TEMP_S2D0_REG: 420 case MAX6621_TEMP_S2D1_REG: 421 case MAX6621_TEMP_S3D0_REG: 422 case MAX6621_TEMP_S3D1_REG: 423 case MAX6621_TEMP_MAX_REG: 424 case MAX6621_TEMP_S0_ALERT_REG: 425 case MAX6621_TEMP_S1_ALERT_REG: 426 case MAX6621_TEMP_S2_ALERT_REG: 427 case MAX6621_TEMP_S3_ALERT_REG: 428 case MAX6621_TEMP_ALERT_CAUSE_REG: 429 return true; 430 } 431 return false; 432 } 433 434 static const struct reg_default max6621_regmap_default[] = { 435 { MAX6621_CONFIG0_REG, MAX6621_CONFIG0_INIT }, 436 { MAX6621_CONFIG1_REG, MAX6621_CONFIG1_INIT }, 437 }; 438 439 static const struct regmap_config max6621_regmap_config = { 440 .reg_bits = 8, 441 .val_bits = 16, 442 .max_register = MAX6621_REG_MAX, 443 .val_format_endian = REGMAP_ENDIAN_LITTLE, 444 .cache_type = REGCACHE_FLAT, 445 .writeable_reg = max6621_writeable_reg, 446 .readable_reg = max6621_readable_reg, 447 .volatile_reg = max6621_volatile_reg, 448 .reg_defaults = max6621_regmap_default, 449 .num_reg_defaults = ARRAY_SIZE(max6621_regmap_default), 450 }; 451 452 static const struct hwmon_channel_info * const max6621_info[] = { 453 HWMON_CHANNEL_INFO(chip, 454 HWMON_C_REGISTER_TZ), 455 HWMON_CHANNEL_INFO(temp, 456 HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_OFFSET, 457 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, 458 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, 459 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, 460 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL, 461 HWMON_T_INPUT | HWMON_T_LABEL, 462 HWMON_T_INPUT | HWMON_T_LABEL, 463 HWMON_T_INPUT | HWMON_T_LABEL, 464 HWMON_T_INPUT | HWMON_T_LABEL), 465 NULL 466 }; 467 468 static const struct hwmon_ops max6621_hwmon_ops = { 469 .read = max6621_read, 470 .write = max6621_write, 471 .read_string = max6621_read_string, 472 .is_visible = max6621_is_visible, 473 }; 474 475 static const struct hwmon_chip_info max6621_chip_info = { 476 .ops = &max6621_hwmon_ops, 477 .info = max6621_info, 478 }; 479 480 static int max6621_probe(struct i2c_client *client) 481 { 482 struct device *dev = &client->dev; 483 struct max6621_data *data; 484 struct device *hwmon_dev; 485 int i; 486 int ret; 487 488 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 489 if (!data) 490 return -ENOMEM; 491 492 data->regmap = devm_regmap_init_i2c(client, &max6621_regmap_config); 493 if (IS_ERR(data->regmap)) 494 return PTR_ERR(data->regmap); 495 496 i2c_set_clientdata(client, data); 497 data->client = client; 498 499 /* Set CONFIG0 register masking temperature alerts and PEC. */ 500 ret = regmap_write(data->regmap, MAX6621_CONFIG0_REG, 501 MAX6621_CONFIG0_INIT); 502 if (ret) 503 return ret; 504 505 /* Set CONFIG1 register for PEC access retry number. */ 506 ret = regmap_write(data->regmap, MAX6621_CONFIG1_REG, 507 MAX6621_CONFIG1_INIT); 508 if (ret) 509 return ret; 510 511 /* Sync registers with hardware. */ 512 regcache_mark_dirty(data->regmap); 513 ret = regcache_sync(data->regmap); 514 if (ret) 515 return ret; 516 517 /* Verify which temperature input registers are enabled. */ 518 for (i = 0; i < MAX6621_TEMP_INPUT_REG_NUM; i++) { 519 ret = i2c_smbus_read_word_data(client, max6621_temp_regs[i]); 520 if (ret < 0) 521 return ret; 522 ret = max6621_verify_reg_data(dev, ret); 523 if (ret) { 524 data->input_chan2reg[i] = -1; 525 continue; 526 } 527 528 data->input_chan2reg[i] = max6621_temp_regs[i]; 529 } 530 531 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 532 data, 533 &max6621_chip_info, 534 NULL); 535 536 return PTR_ERR_OR_ZERO(hwmon_dev); 537 } 538 539 static const struct i2c_device_id max6621_id[] = { 540 { MAX6621_DRV_NAME, 0 }, 541 { } 542 }; 543 MODULE_DEVICE_TABLE(i2c, max6621_id); 544 545 static const struct of_device_id __maybe_unused max6621_of_match[] = { 546 { .compatible = "maxim,max6621" }, 547 { } 548 }; 549 MODULE_DEVICE_TABLE(of, max6621_of_match); 550 551 static struct i2c_driver max6621_driver = { 552 .driver = { 553 .name = MAX6621_DRV_NAME, 554 .of_match_table = of_match_ptr(max6621_of_match), 555 }, 556 .probe = max6621_probe, 557 .id_table = max6621_id, 558 }; 559 560 module_i2c_driver(max6621_driver); 561 562 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>"); 563 MODULE_DESCRIPTION("Driver for Maxim MAX6621"); 564 MODULE_LICENSE("GPL"); 565