1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * STTS751 sensor driver 4 * 5 * Copyright (C) 2016-2017 Istituto Italiano di Tecnologia - RBCS - EDL 6 * Robotics, Brain and Cognitive Sciences department 7 * Electronic Design Laboratory 8 * 9 * Written by Andrea Merello <andrea.merello@gmail.com> 10 * 11 * Based on LM95241 driver and LM90 driver 12 */ 13 14 #include <linux/bitops.h> 15 #include <linux/err.h> 16 #include <linux/hwmon.h> 17 #include <linux/hwmon-sysfs.h> 18 #include <linux/i2c.h> 19 #include <linux/init.h> 20 #include <linux/interrupt.h> 21 #include <linux/jiffies.h> 22 #include <linux/module.h> 23 #include <linux/mutex.h> 24 #include <linux/property.h> 25 #include <linux/slab.h> 26 #include <linux/sysfs.h> 27 #include <linux/util_macros.h> 28 29 #define DEVNAME "stts751" 30 31 static const unsigned short normal_i2c[] = { 32 0x48, 0x49, 0x38, 0x39, /* STTS751-0 */ 33 0x4A, 0x4B, 0x3A, 0x3B, /* STTS751-1 */ 34 I2C_CLIENT_END }; 35 36 #define STTS751_REG_TEMP_H 0x00 37 #define STTS751_REG_STATUS 0x01 38 #define STTS751_STATUS_TRIPT BIT(0) 39 #define STTS751_STATUS_TRIPL BIT(5) 40 #define STTS751_STATUS_TRIPH BIT(6) 41 #define STTS751_REG_TEMP_L 0x02 42 #define STTS751_REG_CONF 0x03 43 #define STTS751_CONF_RES_MASK 0x0C 44 #define STTS751_CONF_RES_SHIFT 2 45 #define STTS751_CONF_EVENT_DIS BIT(7) 46 #define STTS751_CONF_STOP BIT(6) 47 #define STTS751_REG_RATE 0x04 48 #define STTS751_REG_HLIM_H 0x05 49 #define STTS751_REG_HLIM_L 0x06 50 #define STTS751_REG_LLIM_H 0x07 51 #define STTS751_REG_LLIM_L 0x08 52 #define STTS751_REG_TLIM 0x20 53 #define STTS751_REG_HYST 0x21 54 #define STTS751_REG_SMBUS_TO 0x22 55 56 #define STTS751_REG_PROD_ID 0xFD 57 #define STTS751_REG_MAN_ID 0xFE 58 #define STTS751_REG_REV_ID 0xFF 59 60 #define STTS751_0_PROD_ID 0x00 61 #define STTS751_1_PROD_ID 0x01 62 #define ST_MAN_ID 0x53 63 64 /* 65 * Possible update intervals are (in mS): 66 * 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, 31.25 67 * However we are not going to complicate things too much and we stick to the 68 * approx value in mS. 69 */ 70 static const int stts751_intervals[] = { 71 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31 72 }; 73 74 static const struct i2c_device_id stts751_id[] = { 75 { "stts751", 0 }, 76 { } 77 }; 78 79 static const struct of_device_id __maybe_unused stts751_of_match[] = { 80 { .compatible = "stts751" }, 81 { }, 82 }; 83 MODULE_DEVICE_TABLE(of, stts751_of_match); 84 85 struct stts751_priv { 86 struct device *dev; 87 struct i2c_client *client; 88 struct mutex access_lock; 89 u8 interval; 90 int res; 91 int event_max, event_min; 92 int therm; 93 int hyst; 94 bool smbus_timeout; 95 int temp; 96 unsigned long last_update, last_alert_update; 97 u8 config; 98 bool min_alert, max_alert, therm_trip; 99 bool data_valid, alert_valid; 100 bool notify_max, notify_min; 101 }; 102 103 /* 104 * These functions converts temperature from HW format to integer format and 105 * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC. 106 */ 107 static int stts751_to_deg(s16 hw_val) 108 { 109 return hw_val * 125 / 32; 110 } 111 112 static s32 stts751_to_hw(int val) 113 { 114 return DIV_ROUND_CLOSEST(val, 125) * 32; 115 } 116 117 static int stts751_adjust_resolution(struct stts751_priv *priv) 118 { 119 u8 res; 120 121 switch (priv->interval) { 122 case 9: 123 /* 10 bits */ 124 res = 0; 125 break; 126 case 8: 127 /* 11 bits */ 128 res = 1; 129 break; 130 default: 131 /* 12 bits */ 132 res = 3; 133 break; 134 } 135 136 if (priv->res == res) 137 return 0; 138 139 priv->config &= ~STTS751_CONF_RES_MASK; 140 priv->config |= res << STTS751_CONF_RES_SHIFT; 141 dev_dbg(&priv->client->dev, "setting res %d. config %x", 142 res, priv->config); 143 priv->res = res; 144 145 return i2c_smbus_write_byte_data(priv->client, 146 STTS751_REG_CONF, priv->config); 147 } 148 149 static int stts751_update_temp(struct stts751_priv *priv) 150 { 151 s32 integer1, integer2, frac; 152 153 /* 154 * There is a trick here, like in the lm90 driver. We have to read two 155 * registers to get the sensor temperature, but we have to beware a 156 * conversion could occur between the readings. We could use the 157 * one-shot conversion register, but we don't want to do this (disables 158 * hardware monitoring). So the solution used here is to read the high 159 * byte once, then the low byte, then the high byte again. If the new 160 * high byte matches the old one, then we have a valid reading. Else we 161 * have to read the low byte again, and now we believe we have a correct 162 * reading. 163 */ 164 integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); 165 if (integer1 < 0) { 166 dev_dbg(&priv->client->dev, 167 "I2C read failed (temp H). ret: %x\n", integer1); 168 return integer1; 169 } 170 171 frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L); 172 if (frac < 0) { 173 dev_dbg(&priv->client->dev, 174 "I2C read failed (temp L). ret: %x\n", frac); 175 return frac; 176 } 177 178 integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); 179 if (integer2 < 0) { 180 dev_dbg(&priv->client->dev, 181 "I2C 2nd read failed (temp H). ret: %x\n", integer2); 182 return integer2; 183 } 184 185 if (integer1 != integer2) { 186 frac = i2c_smbus_read_byte_data(priv->client, 187 STTS751_REG_TEMP_L); 188 if (frac < 0) { 189 dev_dbg(&priv->client->dev, 190 "I2C 2nd read failed (temp L). ret: %x\n", 191 frac); 192 return frac; 193 } 194 } 195 196 priv->temp = stts751_to_deg((integer1 << 8) | frac); 197 return 0; 198 } 199 200 static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp, 201 u8 hreg, u8 lreg) 202 { 203 s32 hwval; 204 int ret; 205 206 hwval = stts751_to_hw(temp); 207 208 ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8); 209 if (ret) 210 return ret; 211 212 return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff); 213 } 214 215 static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg) 216 { 217 s32 hwval; 218 219 hwval = stts751_to_hw(temp); 220 return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8); 221 } 222 223 static int stts751_read_reg16(struct stts751_priv *priv, int *temp, 224 u8 hreg, u8 lreg) 225 { 226 int integer, frac; 227 228 integer = i2c_smbus_read_byte_data(priv->client, hreg); 229 if (integer < 0) 230 return integer; 231 232 frac = i2c_smbus_read_byte_data(priv->client, lreg); 233 if (frac < 0) 234 return frac; 235 236 *temp = stts751_to_deg((integer << 8) | frac); 237 238 return 0; 239 } 240 241 static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg) 242 { 243 int integer; 244 245 integer = i2c_smbus_read_byte_data(priv->client, reg); 246 if (integer < 0) 247 return integer; 248 249 *temp = stts751_to_deg(integer << 8); 250 251 return 0; 252 } 253 254 /* 255 * Update alert flags without waiting for cache to expire. We detects alerts 256 * immediately for the sake of the alert handler; we still need to deal with 257 * caching to workaround the fact that alarm flags int the status register, 258 * despite what the datasheet claims, gets always cleared on read. 259 */ 260 static int stts751_update_alert(struct stts751_priv *priv) 261 { 262 int ret; 263 bool conv_done; 264 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); 265 266 /* 267 * Add another 10% because if we run faster than the HW conversion 268 * rate we will end up in reporting incorrectly alarms. 269 */ 270 cache_time += cache_time / 10; 271 272 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS); 273 if (ret < 0) 274 return ret; 275 276 dev_dbg(&priv->client->dev, "status reg %x\n", ret); 277 conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL); 278 /* 279 * Reset the cache if the cache time expired, or if we are sure 280 * we have valid data from a device conversion, or if we know 281 * our cache has been never written. 282 * 283 * Note that when the cache has been never written the point is 284 * to correctly initialize the timestamp, rather than clearing 285 * the cache values. 286 * 287 * Note that updating the cache timestamp when we get an alarm flag 288 * is required, otherwise we could incorrectly report alarms to be zero. 289 */ 290 if (time_after(jiffies, priv->last_alert_update + cache_time) || 291 conv_done || !priv->alert_valid) { 292 priv->max_alert = false; 293 priv->min_alert = false; 294 priv->alert_valid = true; 295 priv->last_alert_update = jiffies; 296 dev_dbg(&priv->client->dev, "invalidating alert cache\n"); 297 } 298 299 priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH); 300 priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL); 301 priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT); 302 303 dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n", 304 priv->max_alert, priv->min_alert, priv->therm_trip); 305 306 return 0; 307 } 308 309 static void stts751_alert(struct i2c_client *client, 310 enum i2c_alert_protocol type, unsigned int data) 311 { 312 int ret; 313 struct stts751_priv *priv = i2c_get_clientdata(client); 314 315 if (type != I2C_PROTOCOL_SMBUS_ALERT) 316 return; 317 318 dev_dbg(&client->dev, "alert!"); 319 320 mutex_lock(&priv->access_lock); 321 ret = stts751_update_alert(priv); 322 if (ret < 0) { 323 /* default to worst case */ 324 priv->max_alert = true; 325 priv->min_alert = true; 326 327 dev_warn(priv->dev, 328 "Alert received, but can't communicate to the device. Triggering all alarms!"); 329 } 330 331 if (priv->max_alert) { 332 if (priv->notify_max) 333 dev_notice(priv->dev, "got alert for HIGH temperature"); 334 priv->notify_max = false; 335 336 /* unblock alert poll */ 337 sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm"); 338 } 339 340 if (priv->min_alert) { 341 if (priv->notify_min) 342 dev_notice(priv->dev, "got alert for LOW temperature"); 343 priv->notify_min = false; 344 345 /* unblock alert poll */ 346 sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm"); 347 } 348 349 if (priv->min_alert || priv->max_alert) 350 kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE); 351 352 mutex_unlock(&priv->access_lock); 353 } 354 355 static int stts751_update(struct stts751_priv *priv) 356 { 357 int ret; 358 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); 359 360 if (time_after(jiffies, priv->last_update + cache_time) || 361 !priv->data_valid) { 362 ret = stts751_update_temp(priv); 363 if (ret) 364 return ret; 365 366 ret = stts751_update_alert(priv); 367 if (ret) 368 return ret; 369 priv->data_valid = true; 370 priv->last_update = jiffies; 371 } 372 373 return 0; 374 } 375 376 static ssize_t max_alarm_show(struct device *dev, 377 struct device_attribute *attr, char *buf) 378 { 379 int ret; 380 struct stts751_priv *priv = dev_get_drvdata(dev); 381 382 mutex_lock(&priv->access_lock); 383 ret = stts751_update(priv); 384 if (!ret) 385 priv->notify_max = true; 386 mutex_unlock(&priv->access_lock); 387 if (ret < 0) 388 return ret; 389 390 return snprintf(buf, PAGE_SIZE, "%d\n", priv->max_alert); 391 } 392 393 static ssize_t min_alarm_show(struct device *dev, 394 struct device_attribute *attr, char *buf) 395 { 396 int ret; 397 struct stts751_priv *priv = dev_get_drvdata(dev); 398 399 mutex_lock(&priv->access_lock); 400 ret = stts751_update(priv); 401 if (!ret) 402 priv->notify_min = true; 403 mutex_unlock(&priv->access_lock); 404 if (ret < 0) 405 return ret; 406 407 return snprintf(buf, PAGE_SIZE, "%d\n", priv->min_alert); 408 } 409 410 static ssize_t input_show(struct device *dev, struct device_attribute *attr, 411 char *buf) 412 { 413 int ret; 414 struct stts751_priv *priv = dev_get_drvdata(dev); 415 416 mutex_lock(&priv->access_lock); 417 ret = stts751_update(priv); 418 mutex_unlock(&priv->access_lock); 419 if (ret < 0) 420 return ret; 421 422 return snprintf(buf, PAGE_SIZE, "%d\n", priv->temp); 423 } 424 425 static ssize_t therm_show(struct device *dev, struct device_attribute *attr, 426 char *buf) 427 { 428 struct stts751_priv *priv = dev_get_drvdata(dev); 429 430 return snprintf(buf, PAGE_SIZE, "%d\n", priv->therm); 431 } 432 433 static ssize_t therm_store(struct device *dev, struct device_attribute *attr, 434 const char *buf, size_t count) 435 { 436 int ret; 437 long temp; 438 struct stts751_priv *priv = dev_get_drvdata(dev); 439 440 if (kstrtol(buf, 10, &temp) < 0) 441 return -EINVAL; 442 443 /* HW works in range -64C to +127.937C */ 444 temp = clamp_val(temp, -64000, 127937); 445 mutex_lock(&priv->access_lock); 446 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM); 447 if (ret) 448 goto exit; 449 450 dev_dbg(&priv->client->dev, "setting therm %ld", temp); 451 452 /* 453 * hysteresis reg is relative to therm, so the HW does not need to be 454 * adjusted, we need to update our local copy only. 455 */ 456 priv->hyst = temp - (priv->therm - priv->hyst); 457 priv->therm = temp; 458 459 exit: 460 mutex_unlock(&priv->access_lock); 461 if (ret) 462 return ret; 463 464 return count; 465 } 466 467 static ssize_t hyst_show(struct device *dev, struct device_attribute *attr, 468 char *buf) 469 { 470 struct stts751_priv *priv = dev_get_drvdata(dev); 471 472 return snprintf(buf, PAGE_SIZE, "%d\n", priv->hyst); 473 } 474 475 static ssize_t hyst_store(struct device *dev, struct device_attribute *attr, 476 const char *buf, size_t count) 477 { 478 int ret; 479 long temp; 480 481 struct stts751_priv *priv = dev_get_drvdata(dev); 482 483 if (kstrtol(buf, 10, &temp) < 0) 484 return -EINVAL; 485 486 mutex_lock(&priv->access_lock); 487 /* HW works in range -64C to +127.937C */ 488 temp = clamp_val(temp, -64000, priv->therm); 489 priv->hyst = temp; 490 dev_dbg(&priv->client->dev, "setting hyst %ld", temp); 491 temp = priv->therm - temp; 492 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST); 493 mutex_unlock(&priv->access_lock); 494 if (ret) 495 return ret; 496 497 return count; 498 } 499 500 static ssize_t therm_trip_show(struct device *dev, 501 struct device_attribute *attr, char *buf) 502 { 503 int ret; 504 struct stts751_priv *priv = dev_get_drvdata(dev); 505 506 mutex_lock(&priv->access_lock); 507 ret = stts751_update(priv); 508 mutex_unlock(&priv->access_lock); 509 if (ret < 0) 510 return ret; 511 512 return snprintf(buf, PAGE_SIZE, "%d\n", priv->therm_trip); 513 } 514 515 static ssize_t max_show(struct device *dev, struct device_attribute *attr, 516 char *buf) 517 { 518 struct stts751_priv *priv = dev_get_drvdata(dev); 519 520 return snprintf(buf, PAGE_SIZE, "%d\n", priv->event_max); 521 } 522 523 static ssize_t max_store(struct device *dev, struct device_attribute *attr, 524 const char *buf, size_t count) 525 { 526 int ret; 527 long temp; 528 struct stts751_priv *priv = dev_get_drvdata(dev); 529 530 if (kstrtol(buf, 10, &temp) < 0) 531 return -EINVAL; 532 533 mutex_lock(&priv->access_lock); 534 /* HW works in range -64C to +127.937C */ 535 temp = clamp_val(temp, priv->event_min, 127937); 536 ret = stts751_set_temp_reg16(priv, temp, 537 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); 538 if (ret) 539 goto exit; 540 541 dev_dbg(&priv->client->dev, "setting event max %ld", temp); 542 priv->event_max = temp; 543 ret = count; 544 exit: 545 mutex_unlock(&priv->access_lock); 546 return ret; 547 } 548 549 static ssize_t min_show(struct device *dev, struct device_attribute *attr, 550 char *buf) 551 { 552 struct stts751_priv *priv = dev_get_drvdata(dev); 553 554 return snprintf(buf, PAGE_SIZE, "%d\n", priv->event_min); 555 } 556 557 static ssize_t min_store(struct device *dev, struct device_attribute *attr, 558 const char *buf, size_t count) 559 { 560 int ret; 561 long temp; 562 struct stts751_priv *priv = dev_get_drvdata(dev); 563 564 if (kstrtol(buf, 10, &temp) < 0) 565 return -EINVAL; 566 567 mutex_lock(&priv->access_lock); 568 /* HW works in range -64C to +127.937C */ 569 temp = clamp_val(temp, -64000, priv->event_max); 570 ret = stts751_set_temp_reg16(priv, temp, 571 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); 572 if (ret) 573 goto exit; 574 575 dev_dbg(&priv->client->dev, "setting event min %ld", temp); 576 priv->event_min = temp; 577 ret = count; 578 exit: 579 mutex_unlock(&priv->access_lock); 580 return ret; 581 } 582 583 static ssize_t interval_show(struct device *dev, 584 struct device_attribute *attr, char *buf) 585 { 586 struct stts751_priv *priv = dev_get_drvdata(dev); 587 588 return snprintf(buf, PAGE_SIZE, "%d\n", 589 stts751_intervals[priv->interval]); 590 } 591 592 static ssize_t interval_store(struct device *dev, 593 struct device_attribute *attr, const char *buf, 594 size_t count) 595 { 596 unsigned long val; 597 int idx; 598 int ret = count; 599 struct stts751_priv *priv = dev_get_drvdata(dev); 600 601 if (kstrtoul(buf, 10, &val) < 0) 602 return -EINVAL; 603 604 idx = find_closest_descending(val, stts751_intervals, 605 ARRAY_SIZE(stts751_intervals)); 606 607 dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d", 608 val, idx, stts751_intervals[idx]); 609 610 mutex_lock(&priv->access_lock); 611 if (priv->interval == idx) 612 goto exit; 613 614 /* 615 * In early development stages I've become suspicious about the chip 616 * starting to misbehave if I ever set, even briefly, an invalid 617 * configuration. While I'm not sure this is really needed, be 618 * conservative and set rate/resolution in such an order that avoids 619 * passing through an invalid configuration. 620 */ 621 622 /* speed up: lower the resolution, then modify convrate */ 623 if (priv->interval < idx) { 624 dev_dbg(&priv->client->dev, "lower resolution, then modify convrate"); 625 priv->interval = idx; 626 ret = stts751_adjust_resolution(priv); 627 if (ret) 628 goto exit; 629 } 630 631 ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx); 632 if (ret) 633 goto exit; 634 /* slow down: modify convrate, then raise resolution */ 635 if (priv->interval != idx) { 636 dev_dbg(&priv->client->dev, "modify convrate, then raise resolution"); 637 priv->interval = idx; 638 ret = stts751_adjust_resolution(priv); 639 if (ret) 640 goto exit; 641 } 642 ret = count; 643 exit: 644 mutex_unlock(&priv->access_lock); 645 646 return ret; 647 } 648 649 static int stts751_detect(struct i2c_client *new_client, 650 struct i2c_board_info *info) 651 { 652 struct i2c_adapter *adapter = new_client->adapter; 653 const char *name; 654 int tmp; 655 656 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 657 return -ENODEV; 658 659 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID); 660 if (tmp != ST_MAN_ID) 661 return -ENODEV; 662 663 /* lower temperaure registers always have bits 0-3 set to zero */ 664 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L); 665 if (tmp & 0xf) 666 return -ENODEV; 667 668 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L); 669 if (tmp & 0xf) 670 return -ENODEV; 671 672 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L); 673 if (tmp & 0xf) 674 return -ENODEV; 675 676 /* smbus timeout register always have bits 0-7 set to zero */ 677 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO); 678 if (tmp & 0x7f) 679 return -ENODEV; 680 681 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID); 682 683 switch (tmp) { 684 case STTS751_0_PROD_ID: 685 name = "STTS751-0"; 686 break; 687 case STTS751_1_PROD_ID: 688 name = "STTS751-1"; 689 break; 690 default: 691 return -ENODEV; 692 } 693 dev_dbg(&new_client->dev, "Chip %s detected", name); 694 695 strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE); 696 return 0; 697 } 698 699 static int stts751_read_chip_config(struct stts751_priv *priv) 700 { 701 int ret; 702 int tmp; 703 704 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF); 705 if (ret < 0) 706 return ret; 707 priv->config = ret; 708 priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT; 709 710 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); 711 if (ret < 0) 712 return ret; 713 if (ret >= ARRAY_SIZE(stts751_intervals)) { 714 dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret); 715 return -ENODEV; 716 } 717 priv->interval = ret; 718 719 ret = stts751_read_reg16(priv, &priv->event_max, 720 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); 721 if (ret) 722 return ret; 723 724 ret = stts751_read_reg16(priv, &priv->event_min, 725 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); 726 if (ret) 727 return ret; 728 729 ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM); 730 if (ret) 731 return ret; 732 733 ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST); 734 if (ret) 735 return ret; 736 priv->hyst = priv->therm - tmp; 737 738 return 0; 739 } 740 741 static SENSOR_DEVICE_ATTR_RO(temp1_input, input, 0); 742 static SENSOR_DEVICE_ATTR_RW(temp1_min, min, 0); 743 static SENSOR_DEVICE_ATTR_RW(temp1_max, max, 0); 744 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, min_alarm, 0); 745 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, max_alarm, 0); 746 static SENSOR_DEVICE_ATTR_RW(temp1_crit, therm, 0); 747 static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, hyst, 0); 748 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, therm_trip, 0); 749 static SENSOR_DEVICE_ATTR_RW(update_interval, interval, 0); 750 751 static struct attribute *stts751_attrs[] = { 752 &sensor_dev_attr_temp1_input.dev_attr.attr, 753 &sensor_dev_attr_temp1_min.dev_attr.attr, 754 &sensor_dev_attr_temp1_max.dev_attr.attr, 755 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 756 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 757 &sensor_dev_attr_temp1_crit.dev_attr.attr, 758 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, 759 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, 760 &sensor_dev_attr_update_interval.dev_attr.attr, 761 NULL 762 }; 763 ATTRIBUTE_GROUPS(stts751); 764 765 static int stts751_probe(struct i2c_client *client, 766 const struct i2c_device_id *id) 767 { 768 struct stts751_priv *priv; 769 int ret; 770 bool smbus_nto; 771 int rev_id; 772 773 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); 774 if (!priv) 775 return -ENOMEM; 776 777 priv->client = client; 778 priv->notify_max = true; 779 priv->notify_min = true; 780 i2c_set_clientdata(client, priv); 781 mutex_init(&priv->access_lock); 782 783 if (device_property_present(&client->dev, 784 "smbus-timeout-disable")) { 785 smbus_nto = device_property_read_bool(&client->dev, 786 "smbus-timeout-disable"); 787 788 ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO, 789 smbus_nto ? 0 : 0x80); 790 if (ret) 791 return ret; 792 } 793 794 rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID); 795 if (rev_id < 0) 796 return -ENODEV; 797 if (rev_id != 0x1) { 798 dev_dbg(&client->dev, "Chip revision 0x%x is untested\n", 799 rev_id); 800 } 801 802 ret = stts751_read_chip_config(priv); 803 if (ret) 804 return ret; 805 806 priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS); 807 ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config); 808 if (ret) 809 return ret; 810 811 priv->dev = devm_hwmon_device_register_with_groups(&client->dev, 812 client->name, priv, 813 stts751_groups); 814 return PTR_ERR_OR_ZERO(priv->dev); 815 } 816 817 MODULE_DEVICE_TABLE(i2c, stts751_id); 818 819 static struct i2c_driver stts751_driver = { 820 .class = I2C_CLASS_HWMON, 821 .driver = { 822 .name = DEVNAME, 823 .of_match_table = of_match_ptr(stts751_of_match), 824 }, 825 .probe = stts751_probe, 826 .id_table = stts751_id, 827 .detect = stts751_detect, 828 .alert = stts751_alert, 829 .address_list = normal_i2c, 830 }; 831 832 module_i2c_driver(stts751_driver); 833 834 MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>"); 835 MODULE_DESCRIPTION("STTS751 sensor driver"); 836 MODULE_LICENSE("GPL"); 837