1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ntc_thermistor.c - NTC Thermistors 4 * 5 * Copyright (C) 2010 Samsung Electronics 6 * MyungJoo Ham <myungjoo.ham@samsung.com> 7 */ 8 9 #include <linux/slab.h> 10 #include <linux/module.h> 11 #include <linux/math64.h> 12 #include <linux/mod_devicetable.h> 13 #include <linux/platform_device.h> 14 #include <linux/property.h> 15 #include <linux/err.h> 16 #include <linux/fixp-arith.h> 17 #include <linux/iio/consumer.h> 18 #include <linux/hwmon.h> 19 20 enum ntc_thermistor_type { 21 TYPE_B57330V2103, 22 TYPE_B57891S0103, 23 TYPE_NCPXXWB473, 24 TYPE_NCPXXWF104, 25 TYPE_NCPXXWL333, 26 TYPE_NCPXXXH103, 27 }; 28 29 struct ntc_compensation { 30 int temp_c; 31 unsigned int ohm; 32 }; 33 34 /* 35 * Used as index in a zero-terminated array, holes not allowed so 36 * that NTC_LAST is the first empty array entry. 37 */ 38 enum { 39 NTC_B57330V2103, 40 NTC_B57891S0103, 41 NTC_NCP03WB473, 42 NTC_NCP03WF104, 43 NTC_NCP15WB473, 44 NTC_NCP15WL333, 45 NTC_NCP15XH103, 46 NTC_NCP18WB473, 47 NTC_NCP21WB473, 48 NTC_SSG1404001221, 49 NTC_LAST, 50 }; 51 52 static const struct platform_device_id ntc_thermistor_id[] = { 53 [NTC_B57330V2103] = { "b57330v2103", TYPE_B57330V2103 }, 54 [NTC_B57891S0103] = { "b57891s0103", TYPE_B57891S0103 }, 55 [NTC_NCP03WB473] = { "ncp03wb473", TYPE_NCPXXWB473 }, 56 [NTC_NCP03WF104] = { "ncp03wf104", TYPE_NCPXXWF104 }, 57 [NTC_NCP15WB473] = { "ncp15wb473", TYPE_NCPXXWB473 }, 58 [NTC_NCP15WL333] = { "ncp15wl333", TYPE_NCPXXWL333 }, 59 [NTC_NCP15XH103] = { "ncp15xh103", TYPE_NCPXXXH103 }, 60 [NTC_NCP18WB473] = { "ncp18wb473", TYPE_NCPXXWB473 }, 61 [NTC_NCP21WB473] = { "ncp21wb473", TYPE_NCPXXWB473 }, 62 [NTC_SSG1404001221] = { "ssg1404_001221", TYPE_NCPXXWB473 }, 63 [NTC_LAST] = { }, 64 }; 65 MODULE_DEVICE_TABLE(platform, ntc_thermistor_id); 66 67 /* 68 * A compensation table should be sorted by the values of .ohm 69 * in descending order. 70 * The following compensation tables are from the specification of Murata NTC 71 * Thermistors Datasheet 72 */ 73 static const struct ntc_compensation ncpXXwb473[] = { 74 { .temp_c = -40, .ohm = 1747920 }, 75 { .temp_c = -35, .ohm = 1245428 }, 76 { .temp_c = -30, .ohm = 898485 }, 77 { .temp_c = -25, .ohm = 655802 }, 78 { .temp_c = -20, .ohm = 483954 }, 79 { .temp_c = -15, .ohm = 360850 }, 80 { .temp_c = -10, .ohm = 271697 }, 81 { .temp_c = -5, .ohm = 206463 }, 82 { .temp_c = 0, .ohm = 158214 }, 83 { .temp_c = 5, .ohm = 122259 }, 84 { .temp_c = 10, .ohm = 95227 }, 85 { .temp_c = 15, .ohm = 74730 }, 86 { .temp_c = 20, .ohm = 59065 }, 87 { .temp_c = 25, .ohm = 47000 }, 88 { .temp_c = 30, .ohm = 37643 }, 89 { .temp_c = 35, .ohm = 30334 }, 90 { .temp_c = 40, .ohm = 24591 }, 91 { .temp_c = 45, .ohm = 20048 }, 92 { .temp_c = 50, .ohm = 16433 }, 93 { .temp_c = 55, .ohm = 13539 }, 94 { .temp_c = 60, .ohm = 11209 }, 95 { .temp_c = 65, .ohm = 9328 }, 96 { .temp_c = 70, .ohm = 7798 }, 97 { .temp_c = 75, .ohm = 6544 }, 98 { .temp_c = 80, .ohm = 5518 }, 99 { .temp_c = 85, .ohm = 4674 }, 100 { .temp_c = 90, .ohm = 3972 }, 101 { .temp_c = 95, .ohm = 3388 }, 102 { .temp_c = 100, .ohm = 2902 }, 103 { .temp_c = 105, .ohm = 2494 }, 104 { .temp_c = 110, .ohm = 2150 }, 105 { .temp_c = 115, .ohm = 1860 }, 106 { .temp_c = 120, .ohm = 1615 }, 107 { .temp_c = 125, .ohm = 1406 }, 108 }; 109 static const struct ntc_compensation ncpXXwl333[] = { 110 { .temp_c = -40, .ohm = 1610154 }, 111 { .temp_c = -35, .ohm = 1130850 }, 112 { .temp_c = -30, .ohm = 802609 }, 113 { .temp_c = -25, .ohm = 575385 }, 114 { .temp_c = -20, .ohm = 416464 }, 115 { .temp_c = -15, .ohm = 304219 }, 116 { .temp_c = -10, .ohm = 224193 }, 117 { .temp_c = -5, .ohm = 166623 }, 118 { .temp_c = 0, .ohm = 124850 }, 119 { .temp_c = 5, .ohm = 94287 }, 120 { .temp_c = 10, .ohm = 71747 }, 121 { .temp_c = 15, .ohm = 54996 }, 122 { .temp_c = 20, .ohm = 42455 }, 123 { .temp_c = 25, .ohm = 33000 }, 124 { .temp_c = 30, .ohm = 25822 }, 125 { .temp_c = 35, .ohm = 20335 }, 126 { .temp_c = 40, .ohm = 16115 }, 127 { .temp_c = 45, .ohm = 12849 }, 128 { .temp_c = 50, .ohm = 10306 }, 129 { .temp_c = 55, .ohm = 8314 }, 130 { .temp_c = 60, .ohm = 6746 }, 131 { .temp_c = 65, .ohm = 5503 }, 132 { .temp_c = 70, .ohm = 4513 }, 133 { .temp_c = 75, .ohm = 3721 }, 134 { .temp_c = 80, .ohm = 3084 }, 135 { .temp_c = 85, .ohm = 2569 }, 136 { .temp_c = 90, .ohm = 2151 }, 137 { .temp_c = 95, .ohm = 1809 }, 138 { .temp_c = 100, .ohm = 1529 }, 139 { .temp_c = 105, .ohm = 1299 }, 140 { .temp_c = 110, .ohm = 1108 }, 141 { .temp_c = 115, .ohm = 949 }, 142 { .temp_c = 120, .ohm = 817 }, 143 { .temp_c = 125, .ohm = 707 }, 144 }; 145 146 static const struct ntc_compensation ncpXXwf104[] = { 147 { .temp_c = -40, .ohm = 4397119 }, 148 { .temp_c = -35, .ohm = 3088599 }, 149 { .temp_c = -30, .ohm = 2197225 }, 150 { .temp_c = -25, .ohm = 1581881 }, 151 { .temp_c = -20, .ohm = 1151037 }, 152 { .temp_c = -15, .ohm = 846579 }, 153 { .temp_c = -10, .ohm = 628988 }, 154 { .temp_c = -5, .ohm = 471632 }, 155 { .temp_c = 0, .ohm = 357012 }, 156 { .temp_c = 5, .ohm = 272500 }, 157 { .temp_c = 10, .ohm = 209710 }, 158 { .temp_c = 15, .ohm = 162651 }, 159 { .temp_c = 20, .ohm = 127080 }, 160 { .temp_c = 25, .ohm = 100000 }, 161 { .temp_c = 30, .ohm = 79222 }, 162 { .temp_c = 35, .ohm = 63167 }, 163 { .temp_c = 40, .ohm = 50677 }, 164 { .temp_c = 45, .ohm = 40904 }, 165 { .temp_c = 50, .ohm = 33195 }, 166 { .temp_c = 55, .ohm = 27091 }, 167 { .temp_c = 60, .ohm = 22224 }, 168 { .temp_c = 65, .ohm = 18323 }, 169 { .temp_c = 70, .ohm = 15184 }, 170 { .temp_c = 75, .ohm = 12635 }, 171 { .temp_c = 80, .ohm = 10566 }, 172 { .temp_c = 85, .ohm = 8873 }, 173 { .temp_c = 90, .ohm = 7481 }, 174 { .temp_c = 95, .ohm = 6337 }, 175 { .temp_c = 100, .ohm = 5384 }, 176 { .temp_c = 105, .ohm = 4594 }, 177 { .temp_c = 110, .ohm = 3934 }, 178 { .temp_c = 115, .ohm = 3380 }, 179 { .temp_c = 120, .ohm = 2916 }, 180 { .temp_c = 125, .ohm = 2522 }, 181 }; 182 183 static const struct ntc_compensation ncpXXxh103[] = { 184 { .temp_c = -40, .ohm = 247565 }, 185 { .temp_c = -35, .ohm = 181742 }, 186 { .temp_c = -30, .ohm = 135128 }, 187 { .temp_c = -25, .ohm = 101678 }, 188 { .temp_c = -20, .ohm = 77373 }, 189 { .temp_c = -15, .ohm = 59504 }, 190 { .temp_c = -10, .ohm = 46222 }, 191 { .temp_c = -5, .ohm = 36244 }, 192 { .temp_c = 0, .ohm = 28674 }, 193 { .temp_c = 5, .ohm = 22878 }, 194 { .temp_c = 10, .ohm = 18399 }, 195 { .temp_c = 15, .ohm = 14910 }, 196 { .temp_c = 20, .ohm = 12169 }, 197 { .temp_c = 25, .ohm = 10000 }, 198 { .temp_c = 30, .ohm = 8271 }, 199 { .temp_c = 35, .ohm = 6883 }, 200 { .temp_c = 40, .ohm = 5762 }, 201 { .temp_c = 45, .ohm = 4851 }, 202 { .temp_c = 50, .ohm = 4105 }, 203 { .temp_c = 55, .ohm = 3492 }, 204 { .temp_c = 60, .ohm = 2985 }, 205 { .temp_c = 65, .ohm = 2563 }, 206 { .temp_c = 70, .ohm = 2211 }, 207 { .temp_c = 75, .ohm = 1915 }, 208 { .temp_c = 80, .ohm = 1666 }, 209 { .temp_c = 85, .ohm = 1454 }, 210 { .temp_c = 90, .ohm = 1275 }, 211 { .temp_c = 95, .ohm = 1121 }, 212 { .temp_c = 100, .ohm = 990 }, 213 { .temp_c = 105, .ohm = 876 }, 214 { .temp_c = 110, .ohm = 779 }, 215 { .temp_c = 115, .ohm = 694 }, 216 { .temp_c = 120, .ohm = 620 }, 217 { .temp_c = 125, .ohm = 556 }, 218 }; 219 220 /* 221 * The following compensation tables are from the specifications in EPCOS NTC 222 * Thermistors Datasheets 223 */ 224 static const struct ntc_compensation b57330v2103[] = { 225 { .temp_c = -40, .ohm = 190030 }, 226 { .temp_c = -35, .ohm = 145360 }, 227 { .temp_c = -30, .ohm = 112060 }, 228 { .temp_c = -25, .ohm = 87041 }, 229 { .temp_c = -20, .ohm = 68104 }, 230 { .temp_c = -15, .ohm = 53665 }, 231 { .temp_c = -10, .ohm = 42576 }, 232 { .temp_c = -5, .ohm = 34001 }, 233 { .temp_c = 0, .ohm = 27326 }, 234 { .temp_c = 5, .ohm = 22096 }, 235 { .temp_c = 10, .ohm = 17973 }, 236 { .temp_c = 15, .ohm = 14703 }, 237 { .temp_c = 20, .ohm = 12090 }, 238 { .temp_c = 25, .ohm = 10000 }, 239 { .temp_c = 30, .ohm = 8311 }, 240 { .temp_c = 35, .ohm = 6941 }, 241 { .temp_c = 40, .ohm = 5825 }, 242 { .temp_c = 45, .ohm = 4911 }, 243 { .temp_c = 50, .ohm = 4158 }, 244 { .temp_c = 55, .ohm = 3536 }, 245 { .temp_c = 60, .ohm = 3019 }, 246 { .temp_c = 65, .ohm = 2588 }, 247 { .temp_c = 70, .ohm = 2227 }, 248 { .temp_c = 75, .ohm = 1924 }, 249 { .temp_c = 80, .ohm = 1668 }, 250 { .temp_c = 85, .ohm = 1451 }, 251 { .temp_c = 90, .ohm = 1266 }, 252 { .temp_c = 95, .ohm = 1108 }, 253 { .temp_c = 100, .ohm = 973 }, 254 { .temp_c = 105, .ohm = 857 }, 255 { .temp_c = 110, .ohm = 757 }, 256 { .temp_c = 115, .ohm = 671 }, 257 { .temp_c = 120, .ohm = 596 }, 258 { .temp_c = 125, .ohm = 531 }, 259 }; 260 261 static const struct ntc_compensation b57891s0103[] = { 262 { .temp_c = -55.0, .ohm = 878900 }, 263 { .temp_c = -50.0, .ohm = 617590 }, 264 { .temp_c = -45.0, .ohm = 439340 }, 265 { .temp_c = -40.0, .ohm = 316180 }, 266 { .temp_c = -35.0, .ohm = 230060 }, 267 { .temp_c = -30.0, .ohm = 169150 }, 268 { .temp_c = -25.0, .ohm = 125550 }, 269 { .temp_c = -20.0, .ohm = 94143 }, 270 { .temp_c = -15.0, .ohm = 71172 }, 271 { .temp_c = -10.0, .ohm = 54308 }, 272 { .temp_c = -5.0, .ohm = 41505 }, 273 { .temp_c = 0.0, .ohm = 32014 }, 274 { .temp_c = 5.0, .ohm = 25011 }, 275 { .temp_c = 10.0, .ohm = 19691 }, 276 { .temp_c = 15.0, .ohm = 15618 }, 277 { .temp_c = 20.0, .ohm = 12474 }, 278 { .temp_c = 25.0, .ohm = 10000 }, 279 { .temp_c = 30.0, .ohm = 8080 }, 280 { .temp_c = 35.0, .ohm = 6569 }, 281 { .temp_c = 40.0, .ohm = 5372 }, 282 { .temp_c = 45.0, .ohm = 4424 }, 283 { .temp_c = 50.0, .ohm = 3661 }, 284 { .temp_c = 55.0, .ohm = 3039 }, 285 { .temp_c = 60.0, .ohm = 2536 }, 286 { .temp_c = 65.0, .ohm = 2128 }, 287 { .temp_c = 70.0, .ohm = 1794 }, 288 { .temp_c = 75.0, .ohm = 1518 }, 289 { .temp_c = 80.0, .ohm = 1290 }, 290 { .temp_c = 85.0, .ohm = 1100 }, 291 { .temp_c = 90.0, .ohm = 942 }, 292 { .temp_c = 95.0, .ohm = 809 }, 293 { .temp_c = 100.0, .ohm = 697 }, 294 { .temp_c = 105.0, .ohm = 604 }, 295 { .temp_c = 110.0, .ohm = 525 }, 296 { .temp_c = 115.0, .ohm = 457 }, 297 { .temp_c = 120.0, .ohm = 400 }, 298 { .temp_c = 125.0, .ohm = 351 }, 299 { .temp_c = 130.0, .ohm = 308 }, 300 { .temp_c = 135.0, .ohm = 272 }, 301 { .temp_c = 140.0, .ohm = 240 }, 302 { .temp_c = 145.0, .ohm = 213 }, 303 { .temp_c = 150.0, .ohm = 189 }, 304 { .temp_c = 155.0, .ohm = 168 }, 305 }; 306 307 struct ntc_type { 308 const struct ntc_compensation *comp; 309 int n_comp; 310 }; 311 312 #define NTC_TYPE(ntc, compensation) \ 313 [(ntc)] = { .comp = (compensation), .n_comp = ARRAY_SIZE(compensation) } 314 315 static const struct ntc_type ntc_type[] = { 316 NTC_TYPE(TYPE_B57330V2103, b57330v2103), 317 NTC_TYPE(TYPE_B57891S0103, b57891s0103), 318 NTC_TYPE(TYPE_NCPXXWB473, ncpXXwb473), 319 NTC_TYPE(TYPE_NCPXXWF104, ncpXXwf104), 320 NTC_TYPE(TYPE_NCPXXWL333, ncpXXwl333), 321 NTC_TYPE(TYPE_NCPXXXH103, ncpXXxh103), 322 }; 323 324 /* 325 * pullup_uV, pullup_ohm, pulldown_ohm, and connect are required. 326 * 327 * How to setup pullup_ohm, pulldown_ohm, and connect is 328 * described at Documentation/hwmon/ntc_thermistor.rst 329 * 330 * pullup/down_ohm: 0 for infinite / not-connected 331 * 332 * chan: iio_channel pointer to communicate with the ADC which the 333 * thermistor is using for conversion of the analog values. 334 */ 335 struct ntc_data { 336 const struct ntc_compensation *comp; 337 int n_comp; 338 unsigned int pullup_uv; 339 unsigned int pullup_ohm; 340 unsigned int pulldown_ohm; 341 enum { NTC_CONNECTED_POSITIVE, NTC_CONNECTED_GROUND } connect; 342 struct iio_channel *chan; 343 }; 344 345 static int ntc_adc_iio_read(struct ntc_data *data) 346 { 347 struct iio_channel *channel = data->chan; 348 int uv, ret; 349 350 ret = iio_read_channel_processed_scale(channel, &uv, 1000); 351 if (ret < 0) { 352 int raw; 353 354 /* 355 * This fallback uses a raw read and then 356 * assumes the ADC is 12 bits, scaling with 357 * a factor 1000 to get to microvolts. 358 */ 359 ret = iio_read_channel_raw(channel, &raw); 360 if (ret < 0) { 361 pr_err("read channel() error: %d\n", ret); 362 return ret; 363 } 364 ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000); 365 if (ret < 0) { 366 /* Assume 12 bit ADC with vref at pullup_uv */ 367 uv = (data->pullup_uv * (s64)raw) >> 12; 368 } 369 } 370 371 return uv; 372 } 373 374 static inline u64 div64_u64_safe(u64 dividend, u64 divisor) 375 { 376 if (divisor == 0 && dividend == 0) 377 return 0; 378 if (divisor == 0) 379 return UINT_MAX; 380 return div64_u64(dividend, divisor); 381 } 382 383 static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv) 384 { 385 u32 puv = data->pullup_uv; 386 u64 n, puo, pdo; 387 puo = data->pullup_ohm; 388 pdo = data->pulldown_ohm; 389 390 if (uv == 0) 391 return (data->connect == NTC_CONNECTED_POSITIVE) ? 392 INT_MAX : 0; 393 if (uv >= puv) 394 return (data->connect == NTC_CONNECTED_POSITIVE) ? 395 0 : INT_MAX; 396 397 if (data->connect == NTC_CONNECTED_POSITIVE && puo == 0) 398 n = div_u64(pdo * (puv - uv), uv); 399 else if (data->connect == NTC_CONNECTED_GROUND && pdo == 0) 400 n = div_u64(puo * uv, puv - uv); 401 else if (data->connect == NTC_CONNECTED_POSITIVE) 402 n = div64_u64_safe(pdo * puo * (puv - uv), 403 puo * uv - pdo * (puv - uv)); 404 else 405 n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv); 406 407 if (n > INT_MAX) 408 n = INT_MAX; 409 return n; 410 } 411 412 static void lookup_comp(struct ntc_data *data, unsigned int ohm, 413 int *i_low, int *i_high) 414 { 415 int start, end, mid; 416 417 /* 418 * Handle special cases: Resistance is higher than or equal to 419 * resistance in first table entry, or resistance is lower or equal 420 * to resistance in last table entry. 421 * In these cases, return i_low == i_high, either pointing to the 422 * beginning or to the end of the table depending on the condition. 423 */ 424 if (ohm >= data->comp[0].ohm) { 425 *i_low = 0; 426 *i_high = 0; 427 return; 428 } 429 if (ohm <= data->comp[data->n_comp - 1].ohm) { 430 *i_low = data->n_comp - 1; 431 *i_high = data->n_comp - 1; 432 return; 433 } 434 435 /* Do a binary search on compensation table */ 436 start = 0; 437 end = data->n_comp; 438 while (start < end) { 439 mid = start + (end - start) / 2; 440 /* 441 * start <= mid < end 442 * data->comp[start].ohm > ohm >= data->comp[end].ohm 443 * 444 * We could check for "ohm == data->comp[mid].ohm" here, but 445 * that is a quite unlikely condition, and we would have to 446 * check again after updating start. Check it at the end instead 447 * for simplicity. 448 */ 449 if (ohm >= data->comp[mid].ohm) { 450 end = mid; 451 } else { 452 start = mid + 1; 453 /* 454 * ohm >= data->comp[start].ohm might be true here, 455 * since we set start to mid + 1. In that case, we are 456 * done. We could keep going, but the condition is quite 457 * likely to occur, so it is worth checking for it. 458 */ 459 if (ohm >= data->comp[start].ohm) 460 end = start; 461 } 462 /* 463 * start <= end 464 * data->comp[start].ohm >= ohm >= data->comp[end].ohm 465 */ 466 } 467 /* 468 * start == end 469 * ohm >= data->comp[end].ohm 470 */ 471 *i_low = end; 472 if (ohm == data->comp[end].ohm) 473 *i_high = end; 474 else 475 *i_high = end - 1; 476 } 477 478 static int get_temp_mc(struct ntc_data *data, unsigned int ohm) 479 { 480 int low, high; 481 int temp; 482 483 lookup_comp(data, ohm, &low, &high); 484 /* 485 * First multiplying the table temperatures with 1000 to get to 486 * millicentigrades (which is what we want) and then interpolating 487 * will give the best precision. 488 */ 489 temp = fixp_linear_interpolate(data->comp[low].ohm, 490 data->comp[low].temp_c * 1000, 491 data->comp[high].ohm, 492 data->comp[high].temp_c * 1000, 493 ohm); 494 return temp; 495 } 496 497 static int ntc_thermistor_get_ohm(struct ntc_data *data) 498 { 499 int read_uv; 500 501 read_uv = ntc_adc_iio_read(data); 502 if (read_uv < 0) 503 return read_uv; 504 return get_ohm_of_thermistor(data, read_uv); 505 } 506 507 static int ntc_read(struct device *dev, enum hwmon_sensor_types type, 508 u32 attr, int channel, long *val) 509 { 510 struct ntc_data *data = dev_get_drvdata(dev); 511 int ohm; 512 513 switch (type) { 514 case hwmon_temp: 515 switch (attr) { 516 case hwmon_temp_input: 517 ohm = ntc_thermistor_get_ohm(data); 518 if (ohm < 0) 519 return ohm; 520 *val = get_temp_mc(data, ohm); 521 return 0; 522 case hwmon_temp_type: 523 *val = 4; 524 return 0; 525 default: 526 break; 527 } 528 break; 529 default: 530 break; 531 } 532 return -EINVAL; 533 } 534 535 static umode_t ntc_is_visible(const void *data, enum hwmon_sensor_types type, 536 u32 attr, int channel) 537 { 538 if (type == hwmon_temp) { 539 switch (attr) { 540 case hwmon_temp_input: 541 case hwmon_temp_type: 542 return 0444; 543 default: 544 break; 545 } 546 } 547 return 0; 548 } 549 550 static const struct hwmon_channel_info * const ntc_info[] = { 551 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), 552 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_TYPE), 553 NULL 554 }; 555 556 static const struct hwmon_ops ntc_hwmon_ops = { 557 .is_visible = ntc_is_visible, 558 .read = ntc_read, 559 }; 560 561 static const struct hwmon_chip_info ntc_chip_info = { 562 .ops = &ntc_hwmon_ops, 563 .info = ntc_info, 564 }; 565 566 static int ntc_thermistor_parse_props(struct device *dev, 567 struct ntc_data *data) 568 { 569 struct iio_channel *chan; 570 enum iio_chan_type type; 571 int ret; 572 573 chan = devm_iio_channel_get(dev, NULL); 574 if (IS_ERR(chan)) 575 return PTR_ERR(chan); 576 577 ret = iio_get_channel_type(chan, &type); 578 if (ret < 0) 579 return ret; 580 581 if (type != IIO_VOLTAGE) 582 return -EINVAL; 583 584 ret = device_property_read_u32(dev, "pullup-uv", &data->pullup_uv); 585 if (ret) 586 return dev_err_probe(dev, ret, "pullup-uv not specified\n"); 587 588 ret = device_property_read_u32(dev, "pullup-ohm", &data->pullup_ohm); 589 if (ret) 590 return dev_err_probe(dev, ret, "pullup-ohm not specified\n"); 591 592 ret = device_property_read_u32(dev, "pulldown-ohm", &data->pulldown_ohm); 593 if (ret) 594 return dev_err_probe(dev, ret, "pulldown-ohm not specified\n"); 595 596 if (device_property_read_bool(dev, "connected-positive")) 597 data->connect = NTC_CONNECTED_POSITIVE; 598 else /* status change should be possible if not always on. */ 599 data->connect = NTC_CONNECTED_GROUND; 600 601 data->chan = chan; 602 603 return 0; 604 } 605 606 static int ntc_thermistor_probe(struct platform_device *pdev) 607 { 608 struct device *dev = &pdev->dev; 609 const struct platform_device_id *pdev_id; 610 struct device *hwmon_dev; 611 struct ntc_data *data; 612 int ret; 613 614 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 615 if (!data) 616 return -ENOMEM; 617 618 ret = ntc_thermistor_parse_props(dev, data); 619 if (ret) 620 return ret; 621 622 if (data->pullup_uv == 0 || 623 (data->pullup_ohm == 0 && data->connect == 624 NTC_CONNECTED_GROUND) || 625 (data->pulldown_ohm == 0 && data->connect == 626 NTC_CONNECTED_POSITIVE) || 627 (data->connect != NTC_CONNECTED_POSITIVE && 628 data->connect != NTC_CONNECTED_GROUND)) { 629 dev_err(dev, "Required data to use NTC driver not supplied.\n"); 630 return -EINVAL; 631 } 632 633 pdev_id = device_get_match_data(dev); 634 635 if (pdev_id->driver_data >= ARRAY_SIZE(ntc_type)) { 636 dev_err(dev, "Unknown device type: %lu(%s)\n", 637 pdev_id->driver_data, pdev_id->name); 638 return -EINVAL; 639 } 640 641 data->comp = ntc_type[pdev_id->driver_data].comp; 642 data->n_comp = ntc_type[pdev_id->driver_data].n_comp; 643 644 hwmon_dev = devm_hwmon_device_register_with_info(dev, pdev_id->name, 645 data, &ntc_chip_info, 646 NULL); 647 if (IS_ERR(hwmon_dev)) { 648 dev_err(dev, "unable to register as hwmon device.\n"); 649 return PTR_ERR(hwmon_dev); 650 } 651 652 dev_info(dev, "Thermistor type: %s successfully probed.\n", 653 pdev_id->name); 654 655 return 0; 656 } 657 658 static const struct of_device_id ntc_match[] = { 659 { .compatible = "epcos,b57330v2103", 660 .data = &ntc_thermistor_id[NTC_B57330V2103]}, 661 { .compatible = "epcos,b57891s0103", 662 .data = &ntc_thermistor_id[NTC_B57891S0103] }, 663 { .compatible = "murata,ncp03wb473", 664 .data = &ntc_thermistor_id[NTC_NCP03WB473] }, 665 { .compatible = "murata,ncp03wf104", 666 .data = &ntc_thermistor_id[NTC_NCP03WF104] }, 667 { .compatible = "murata,ncp15wb473", 668 .data = &ntc_thermistor_id[NTC_NCP15WB473] }, 669 { .compatible = "murata,ncp15wl333", 670 .data = &ntc_thermistor_id[NTC_NCP15WL333] }, 671 { .compatible = "murata,ncp15xh103", 672 .data = &ntc_thermistor_id[NTC_NCP15XH103] }, 673 { .compatible = "murata,ncp18wb473", 674 .data = &ntc_thermistor_id[NTC_NCP18WB473] }, 675 { .compatible = "murata,ncp21wb473", 676 .data = &ntc_thermistor_id[NTC_NCP21WB473] }, 677 { .compatible = "samsung,1404-001221", 678 .data = &ntc_thermistor_id[NTC_SSG1404001221] }, 679 680 /* Usage of vendor name "ntc" is deprecated */ 681 { .compatible = "ntc,ncp03wb473", 682 .data = &ntc_thermistor_id[NTC_NCP03WB473] }, 683 { .compatible = "ntc,ncp15wb473", 684 .data = &ntc_thermistor_id[NTC_NCP15WB473] }, 685 { .compatible = "ntc,ncp15wl333", 686 .data = &ntc_thermistor_id[NTC_NCP15WL333] }, 687 { .compatible = "ntc,ncp18wb473", 688 .data = &ntc_thermistor_id[NTC_NCP18WB473] }, 689 { .compatible = "ntc,ncp21wb473", 690 .data = &ntc_thermistor_id[NTC_NCP21WB473] }, 691 { }, 692 }; 693 MODULE_DEVICE_TABLE(of, ntc_match); 694 695 static struct platform_driver ntc_thermistor_driver = { 696 .driver = { 697 .name = "ntc-thermistor", 698 .of_match_table = ntc_match, 699 }, 700 .probe = ntc_thermistor_probe, 701 .id_table = ntc_thermistor_id, 702 }; 703 704 module_platform_driver(ntc_thermistor_driver); 705 706 MODULE_DESCRIPTION("NTC Thermistor Driver"); 707 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); 708 MODULE_LICENSE("GPL"); 709 MODULE_ALIAS("platform:ntc-thermistor"); 710