1 /* 2 * ntc_thermistor.c - NTC Thermistors 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * MyungJoo Ham <myungjoo.ham@samsung.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 */ 22 23 #include <linux/slab.h> 24 #include <linux/module.h> 25 #include <linux/pm_runtime.h> 26 #include <linux/math64.h> 27 #include <linux/platform_device.h> 28 #include <linux/err.h> 29 #include <linux/of.h> 30 #include <linux/of_device.h> 31 32 #include <linux/platform_data/ntc_thermistor.h> 33 34 #include <linux/iio/iio.h> 35 #include <linux/iio/machine.h> 36 #include <linux/iio/driver.h> 37 #include <linux/iio/consumer.h> 38 39 #include <linux/hwmon.h> 40 #include <linux/hwmon-sysfs.h> 41 #include <linux/thermal.h> 42 43 struct ntc_compensation { 44 int temp_c; 45 unsigned int ohm; 46 }; 47 48 /* Order matters, ntc_match references the entries by index */ 49 static const struct platform_device_id ntc_thermistor_id[] = { 50 { "ncp15wb473", TYPE_NCPXXWB473 }, 51 { "ncp18wb473", TYPE_NCPXXWB473 }, 52 { "ncp21wb473", TYPE_NCPXXWB473 }, 53 { "ncp03wb473", TYPE_NCPXXWB473 }, 54 { "ncp15wl333", TYPE_NCPXXWL333 }, 55 { "b57330v2103", TYPE_B57330V2103}, 56 { }, 57 }; 58 59 /* 60 * A compensation table should be sorted by the values of .ohm 61 * in descending order. 62 * The following compensation tables are from the specification of Murata NTC 63 * Thermistors Datasheet 64 */ 65 static const struct ntc_compensation ncpXXwb473[] = { 66 { .temp_c = -40, .ohm = 1747920 }, 67 { .temp_c = -35, .ohm = 1245428 }, 68 { .temp_c = -30, .ohm = 898485 }, 69 { .temp_c = -25, .ohm = 655802 }, 70 { .temp_c = -20, .ohm = 483954 }, 71 { .temp_c = -15, .ohm = 360850 }, 72 { .temp_c = -10, .ohm = 271697 }, 73 { .temp_c = -5, .ohm = 206463 }, 74 { .temp_c = 0, .ohm = 158214 }, 75 { .temp_c = 5, .ohm = 122259 }, 76 { .temp_c = 10, .ohm = 95227 }, 77 { .temp_c = 15, .ohm = 74730 }, 78 { .temp_c = 20, .ohm = 59065 }, 79 { .temp_c = 25, .ohm = 47000 }, 80 { .temp_c = 30, .ohm = 37643 }, 81 { .temp_c = 35, .ohm = 30334 }, 82 { .temp_c = 40, .ohm = 24591 }, 83 { .temp_c = 45, .ohm = 20048 }, 84 { .temp_c = 50, .ohm = 16433 }, 85 { .temp_c = 55, .ohm = 13539 }, 86 { .temp_c = 60, .ohm = 11209 }, 87 { .temp_c = 65, .ohm = 9328 }, 88 { .temp_c = 70, .ohm = 7798 }, 89 { .temp_c = 75, .ohm = 6544 }, 90 { .temp_c = 80, .ohm = 5518 }, 91 { .temp_c = 85, .ohm = 4674 }, 92 { .temp_c = 90, .ohm = 3972 }, 93 { .temp_c = 95, .ohm = 3388 }, 94 { .temp_c = 100, .ohm = 2902 }, 95 { .temp_c = 105, .ohm = 2494 }, 96 { .temp_c = 110, .ohm = 2150 }, 97 { .temp_c = 115, .ohm = 1860 }, 98 { .temp_c = 120, .ohm = 1615 }, 99 { .temp_c = 125, .ohm = 1406 }, 100 }; 101 static const struct ntc_compensation ncpXXwl333[] = { 102 { .temp_c = -40, .ohm = 1610154 }, 103 { .temp_c = -35, .ohm = 1130850 }, 104 { .temp_c = -30, .ohm = 802609 }, 105 { .temp_c = -25, .ohm = 575385 }, 106 { .temp_c = -20, .ohm = 416464 }, 107 { .temp_c = -15, .ohm = 304219 }, 108 { .temp_c = -10, .ohm = 224193 }, 109 { .temp_c = -5, .ohm = 166623 }, 110 { .temp_c = 0, .ohm = 124850 }, 111 { .temp_c = 5, .ohm = 94287 }, 112 { .temp_c = 10, .ohm = 71747 }, 113 { .temp_c = 15, .ohm = 54996 }, 114 { .temp_c = 20, .ohm = 42455 }, 115 { .temp_c = 25, .ohm = 33000 }, 116 { .temp_c = 30, .ohm = 25822 }, 117 { .temp_c = 35, .ohm = 20335 }, 118 { .temp_c = 40, .ohm = 16115 }, 119 { .temp_c = 45, .ohm = 12849 }, 120 { .temp_c = 50, .ohm = 10306 }, 121 { .temp_c = 55, .ohm = 8314 }, 122 { .temp_c = 60, .ohm = 6746 }, 123 { .temp_c = 65, .ohm = 5503 }, 124 { .temp_c = 70, .ohm = 4513 }, 125 { .temp_c = 75, .ohm = 3721 }, 126 { .temp_c = 80, .ohm = 3084 }, 127 { .temp_c = 85, .ohm = 2569 }, 128 { .temp_c = 90, .ohm = 2151 }, 129 { .temp_c = 95, .ohm = 1809 }, 130 { .temp_c = 100, .ohm = 1529 }, 131 { .temp_c = 105, .ohm = 1299 }, 132 { .temp_c = 110, .ohm = 1108 }, 133 { .temp_c = 115, .ohm = 949 }, 134 { .temp_c = 120, .ohm = 817 }, 135 { .temp_c = 125, .ohm = 707 }, 136 }; 137 138 /* 139 * The following compensation table is from the specification of EPCOS NTC 140 * Thermistors Datasheet 141 */ 142 static const struct ntc_compensation b57330v2103[] = { 143 { .temp_c = -40, .ohm = 190030 }, 144 { .temp_c = -35, .ohm = 145360 }, 145 { .temp_c = -30, .ohm = 112060 }, 146 { .temp_c = -25, .ohm = 87041 }, 147 { .temp_c = -20, .ohm = 68104 }, 148 { .temp_c = -15, .ohm = 53665 }, 149 { .temp_c = -10, .ohm = 42576 }, 150 { .temp_c = -5, .ohm = 34001 }, 151 { .temp_c = 0, .ohm = 27326 }, 152 { .temp_c = 5, .ohm = 22096 }, 153 { .temp_c = 10, .ohm = 17973 }, 154 { .temp_c = 15, .ohm = 14703 }, 155 { .temp_c = 20, .ohm = 12090 }, 156 { .temp_c = 25, .ohm = 10000 }, 157 { .temp_c = 30, .ohm = 8311 }, 158 { .temp_c = 35, .ohm = 6941 }, 159 { .temp_c = 40, .ohm = 5825 }, 160 { .temp_c = 45, .ohm = 4911 }, 161 { .temp_c = 50, .ohm = 4158 }, 162 { .temp_c = 55, .ohm = 3536 }, 163 { .temp_c = 60, .ohm = 3019 }, 164 { .temp_c = 65, .ohm = 2588 }, 165 { .temp_c = 70, .ohm = 2227 }, 166 { .temp_c = 75, .ohm = 1924 }, 167 { .temp_c = 80, .ohm = 1668 }, 168 { .temp_c = 85, .ohm = 1451 }, 169 { .temp_c = 90, .ohm = 1266 }, 170 { .temp_c = 95, .ohm = 1108 }, 171 { .temp_c = 100, .ohm = 973 }, 172 { .temp_c = 105, .ohm = 857 }, 173 { .temp_c = 110, .ohm = 757 }, 174 { .temp_c = 115, .ohm = 671 }, 175 { .temp_c = 120, .ohm = 596 }, 176 { .temp_c = 125, .ohm = 531 }, 177 }; 178 179 struct ntc_data { 180 struct device *hwmon_dev; 181 struct ntc_thermistor_platform_data *pdata; 182 const struct ntc_compensation *comp; 183 struct device *dev; 184 int n_comp; 185 char name[PLATFORM_NAME_SIZE]; 186 struct thermal_zone_device *tz; 187 }; 188 189 #if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO) 190 static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata) 191 { 192 struct iio_channel *channel = pdata->chan; 193 s64 result; 194 int val, ret; 195 196 ret = iio_read_channel_raw(channel, &val); 197 if (ret < 0) { 198 pr_err("read channel() error: %d\n", ret); 199 return ret; 200 } 201 202 /* unit: mV */ 203 result = pdata->pullup_uv * (s64) val; 204 result >>= 12; 205 206 return (int)result; 207 } 208 209 static const struct of_device_id ntc_match[] = { 210 { .compatible = "murata,ncp15wb473", 211 .data = &ntc_thermistor_id[0] }, 212 { .compatible = "murata,ncp18wb473", 213 .data = &ntc_thermistor_id[1] }, 214 { .compatible = "murata,ncp21wb473", 215 .data = &ntc_thermistor_id[2] }, 216 { .compatible = "murata,ncp03wb473", 217 .data = &ntc_thermistor_id[3] }, 218 { .compatible = "murata,ncp15wl333", 219 .data = &ntc_thermistor_id[4] }, 220 { .compatible = "epcos,b57330v2103", 221 .data = &ntc_thermistor_id[5]}, 222 223 /* Usage of vendor name "ntc" is deprecated */ 224 { .compatible = "ntc,ncp15wb473", 225 .data = &ntc_thermistor_id[0] }, 226 { .compatible = "ntc,ncp18wb473", 227 .data = &ntc_thermistor_id[1] }, 228 { .compatible = "ntc,ncp21wb473", 229 .data = &ntc_thermistor_id[2] }, 230 { .compatible = "ntc,ncp03wb473", 231 .data = &ntc_thermistor_id[3] }, 232 { .compatible = "ntc,ncp15wl333", 233 .data = &ntc_thermistor_id[4] }, 234 { }, 235 }; 236 MODULE_DEVICE_TABLE(of, ntc_match); 237 238 static struct ntc_thermistor_platform_data * 239 ntc_thermistor_parse_dt(struct platform_device *pdev) 240 { 241 struct iio_channel *chan; 242 struct device_node *np = pdev->dev.of_node; 243 struct ntc_thermistor_platform_data *pdata; 244 245 if (!np) 246 return NULL; 247 248 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 249 if (!pdata) 250 return ERR_PTR(-ENOMEM); 251 252 chan = iio_channel_get(&pdev->dev, NULL); 253 if (IS_ERR(chan)) 254 return ERR_CAST(chan); 255 256 if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv)) 257 return ERR_PTR(-ENODEV); 258 if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm)) 259 return ERR_PTR(-ENODEV); 260 if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm)) 261 return ERR_PTR(-ENODEV); 262 263 if (of_find_property(np, "connected-positive", NULL)) 264 pdata->connect = NTC_CONNECTED_POSITIVE; 265 else /* status change should be possible if not always on. */ 266 pdata->connect = NTC_CONNECTED_GROUND; 267 268 pdata->chan = chan; 269 pdata->read_uv = ntc_adc_iio_read; 270 271 return pdata; 272 } 273 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata) 274 { 275 if (pdata->chan) 276 iio_channel_release(pdata->chan); 277 } 278 #else 279 static struct ntc_thermistor_platform_data * 280 ntc_thermistor_parse_dt(struct platform_device *pdev) 281 { 282 return NULL; 283 } 284 285 #define ntc_match NULL 286 287 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata) 288 { } 289 #endif 290 291 static inline u64 div64_u64_safe(u64 dividend, u64 divisor) 292 { 293 if (divisor == 0 && dividend == 0) 294 return 0; 295 if (divisor == 0) 296 return UINT_MAX; 297 return div64_u64(dividend, divisor); 298 } 299 300 static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv) 301 { 302 struct ntc_thermistor_platform_data *pdata = data->pdata; 303 u64 mv = uv / 1000; 304 u64 pmv = pdata->pullup_uv / 1000; 305 u64 n, puo, pdo; 306 puo = pdata->pullup_ohm; 307 pdo = pdata->pulldown_ohm; 308 309 if (mv == 0) { 310 if (pdata->connect == NTC_CONNECTED_POSITIVE) 311 return INT_MAX; 312 return 0; 313 } 314 if (mv >= pmv) 315 return (pdata->connect == NTC_CONNECTED_POSITIVE) ? 316 0 : INT_MAX; 317 318 if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0) 319 n = div64_u64_safe(pdo * (pmv - mv), mv); 320 else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0) 321 n = div64_u64_safe(puo * mv, pmv - mv); 322 else if (pdata->connect == NTC_CONNECTED_POSITIVE) 323 n = div64_u64_safe(pdo * puo * (pmv - mv), 324 puo * mv - pdo * (pmv - mv)); 325 else 326 n = div64_u64_safe(pdo * puo * mv, pdo * (pmv - mv) - puo * mv); 327 328 if (n > INT_MAX) 329 n = INT_MAX; 330 return n; 331 } 332 333 static void lookup_comp(struct ntc_data *data, unsigned int ohm, 334 int *i_low, int *i_high) 335 { 336 int start, end, mid; 337 338 /* 339 * Handle special cases: Resistance is higher than or equal to 340 * resistance in first table entry, or resistance is lower or equal 341 * to resistance in last table entry. 342 * In these cases, return i_low == i_high, either pointing to the 343 * beginning or to the end of the table depending on the condition. 344 */ 345 if (ohm >= data->comp[0].ohm) { 346 *i_low = 0; 347 *i_high = 0; 348 return; 349 } 350 if (ohm <= data->comp[data->n_comp - 1].ohm) { 351 *i_low = data->n_comp - 1; 352 *i_high = data->n_comp - 1; 353 return; 354 } 355 356 /* Do a binary search on compensation table */ 357 start = 0; 358 end = data->n_comp; 359 while (start < end) { 360 mid = start + (end - start) / 2; 361 /* 362 * start <= mid < end 363 * data->comp[start].ohm > ohm >= data->comp[end].ohm 364 * 365 * We could check for "ohm == data->comp[mid].ohm" here, but 366 * that is a quite unlikely condition, and we would have to 367 * check again after updating start. Check it at the end instead 368 * for simplicity. 369 */ 370 if (ohm >= data->comp[mid].ohm) { 371 end = mid; 372 } else { 373 start = mid + 1; 374 /* 375 * ohm >= data->comp[start].ohm might be true here, 376 * since we set start to mid + 1. In that case, we are 377 * done. We could keep going, but the condition is quite 378 * likely to occur, so it is worth checking for it. 379 */ 380 if (ohm >= data->comp[start].ohm) 381 end = start; 382 } 383 /* 384 * start <= end 385 * data->comp[start].ohm >= ohm >= data->comp[end].ohm 386 */ 387 } 388 /* 389 * start == end 390 * ohm >= data->comp[end].ohm 391 */ 392 *i_low = end; 393 if (ohm == data->comp[end].ohm) 394 *i_high = end; 395 else 396 *i_high = end - 1; 397 } 398 399 static int get_temp_mc(struct ntc_data *data, unsigned int ohm) 400 { 401 int low, high; 402 int temp; 403 404 lookup_comp(data, ohm, &low, &high); 405 if (low == high) { 406 /* Unable to use linear approximation */ 407 temp = data->comp[low].temp_c * 1000; 408 } else { 409 temp = data->comp[low].temp_c * 1000 + 410 ((data->comp[high].temp_c - data->comp[low].temp_c) * 411 1000 * ((int)ohm - (int)data->comp[low].ohm)) / 412 ((int)data->comp[high].ohm - (int)data->comp[low].ohm); 413 } 414 return temp; 415 } 416 417 static int ntc_thermistor_get_ohm(struct ntc_data *data) 418 { 419 int read_uv; 420 421 if (data->pdata->read_ohm) 422 return data->pdata->read_ohm(); 423 424 if (data->pdata->read_uv) { 425 read_uv = data->pdata->read_uv(data->pdata); 426 if (read_uv < 0) 427 return read_uv; 428 return get_ohm_of_thermistor(data, read_uv); 429 } 430 return -EINVAL; 431 } 432 433 static int ntc_read_temp(void *dev, long *temp) 434 { 435 struct ntc_data *data = dev_get_drvdata(dev); 436 int ohm; 437 438 ohm = ntc_thermistor_get_ohm(data); 439 if (ohm < 0) 440 return ohm; 441 442 *temp = get_temp_mc(data, ohm); 443 444 return 0; 445 } 446 447 static ssize_t ntc_show_name(struct device *dev, 448 struct device_attribute *attr, char *buf) 449 { 450 struct ntc_data *data = dev_get_drvdata(dev); 451 452 return sprintf(buf, "%s\n", data->name); 453 } 454 455 static ssize_t ntc_show_type(struct device *dev, 456 struct device_attribute *attr, char *buf) 457 { 458 return sprintf(buf, "4\n"); 459 } 460 461 static ssize_t ntc_show_temp(struct device *dev, 462 struct device_attribute *attr, char *buf) 463 { 464 struct ntc_data *data = dev_get_drvdata(dev); 465 int ohm; 466 467 ohm = ntc_thermistor_get_ohm(data); 468 if (ohm < 0) 469 return ohm; 470 471 return sprintf(buf, "%d\n", get_temp_mc(data, ohm)); 472 } 473 474 static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0); 475 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0); 476 static DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL); 477 478 static struct attribute *ntc_attributes[] = { 479 &dev_attr_name.attr, 480 &sensor_dev_attr_temp1_type.dev_attr.attr, 481 &sensor_dev_attr_temp1_input.dev_attr.attr, 482 NULL, 483 }; 484 485 static const struct attribute_group ntc_attr_group = { 486 .attrs = ntc_attributes, 487 }; 488 489 static int ntc_thermistor_probe(struct platform_device *pdev) 490 { 491 const struct of_device_id *of_id = 492 of_match_device(of_match_ptr(ntc_match), &pdev->dev); 493 const struct platform_device_id *pdev_id; 494 struct ntc_thermistor_platform_data *pdata; 495 struct ntc_data *data; 496 int ret; 497 498 pdata = ntc_thermistor_parse_dt(pdev); 499 if (IS_ERR(pdata)) 500 return PTR_ERR(pdata); 501 else if (pdata == NULL) 502 pdata = dev_get_platdata(&pdev->dev); 503 504 if (!pdata) { 505 dev_err(&pdev->dev, "No platform init data supplied.\n"); 506 return -ENODEV; 507 } 508 509 /* Either one of the two is required. */ 510 if (!pdata->read_uv && !pdata->read_ohm) { 511 dev_err(&pdev->dev, 512 "Both read_uv and read_ohm missing. Need either one of the two.\n"); 513 return -EINVAL; 514 } 515 516 if (pdata->read_uv && pdata->read_ohm) { 517 dev_warn(&pdev->dev, 518 "Only one of read_uv and read_ohm is needed; ignoring read_uv.\n"); 519 pdata->read_uv = NULL; 520 } 521 522 if (pdata->read_uv && (pdata->pullup_uv == 0 || 523 (pdata->pullup_ohm == 0 && pdata->connect == 524 NTC_CONNECTED_GROUND) || 525 (pdata->pulldown_ohm == 0 && pdata->connect == 526 NTC_CONNECTED_POSITIVE) || 527 (pdata->connect != NTC_CONNECTED_POSITIVE && 528 pdata->connect != NTC_CONNECTED_GROUND))) { 529 dev_err(&pdev->dev, 530 "Required data to use read_uv not supplied.\n"); 531 return -EINVAL; 532 } 533 534 data = devm_kzalloc(&pdev->dev, sizeof(struct ntc_data), GFP_KERNEL); 535 if (!data) 536 return -ENOMEM; 537 538 pdev_id = of_id ? of_id->data : platform_get_device_id(pdev); 539 540 data->dev = &pdev->dev; 541 data->pdata = pdata; 542 strlcpy(data->name, pdev_id->name, sizeof(data->name)); 543 544 switch (pdev_id->driver_data) { 545 case TYPE_NCPXXWB473: 546 data->comp = ncpXXwb473; 547 data->n_comp = ARRAY_SIZE(ncpXXwb473); 548 break; 549 case TYPE_NCPXXWL333: 550 data->comp = ncpXXwl333; 551 data->n_comp = ARRAY_SIZE(ncpXXwl333); 552 break; 553 case TYPE_B57330V2103: 554 data->comp = b57330v2103; 555 data->n_comp = ARRAY_SIZE(b57330v2103); 556 break; 557 default: 558 dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n", 559 pdev_id->driver_data, pdev_id->name); 560 return -EINVAL; 561 } 562 563 platform_set_drvdata(pdev, data); 564 565 ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group); 566 if (ret) { 567 dev_err(data->dev, "unable to create sysfs files\n"); 568 return ret; 569 } 570 571 data->hwmon_dev = hwmon_device_register(data->dev); 572 if (IS_ERR(data->hwmon_dev)) { 573 dev_err(data->dev, "unable to register as hwmon device.\n"); 574 ret = PTR_ERR(data->hwmon_dev); 575 goto err_after_sysfs; 576 } 577 578 dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n", 579 pdev_id->name); 580 581 data->tz = thermal_zone_of_sensor_register(data->dev, 0, data->dev, 582 ntc_read_temp, NULL); 583 if (IS_ERR(data->tz)) { 584 dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n"); 585 data->tz = NULL; 586 } 587 588 return 0; 589 err_after_sysfs: 590 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group); 591 ntc_iio_channel_release(pdata); 592 return ret; 593 } 594 595 static int ntc_thermistor_remove(struct platform_device *pdev) 596 { 597 struct ntc_data *data = platform_get_drvdata(pdev); 598 struct ntc_thermistor_platform_data *pdata = data->pdata; 599 600 hwmon_device_unregister(data->hwmon_dev); 601 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group); 602 ntc_iio_channel_release(pdata); 603 604 thermal_zone_of_sensor_unregister(data->dev, data->tz); 605 606 return 0; 607 } 608 609 static struct platform_driver ntc_thermistor_driver = { 610 .driver = { 611 .name = "ntc-thermistor", 612 .owner = THIS_MODULE, 613 .of_match_table = of_match_ptr(ntc_match), 614 }, 615 .probe = ntc_thermistor_probe, 616 .remove = ntc_thermistor_remove, 617 .id_table = ntc_thermistor_id, 618 }; 619 620 module_platform_driver(ntc_thermistor_driver); 621 622 MODULE_DESCRIPTION("NTC Thermistor Driver"); 623 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); 624 MODULE_LICENSE("GPL"); 625 MODULE_ALIAS("platform:ntc-thermistor"); 626