drivers/hwmon/ntc_thermistor.c

   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         { "ncp03wf104", TYPE_NCPXXWF104 },
  57         { "ncp15xh103", TYPE_NCPXXXH103 },
  58         { },
  59 };
  60
  61 /*
  62  * A compensation table should be sorted by the values of .ohm
  63  * in descending order.
  64  * The following compensation tables are from the specification of Murata NTC
  65  * Thermistors Datasheet
  66  */
  67 static const struct ntc_compensation ncpXXwb473[] = {
  68         { .temp_c       = -40, .ohm     = 1747920 },
  69         { .temp_c       = -35, .ohm     = 1245428 },
  70         { .temp_c       = -30, .ohm     = 898485 },
  71         { .temp_c       = -25, .ohm     = 655802 },
  72         { .temp_c       = -20, .ohm     = 483954 },
  73         { .temp_c       = -15, .ohm     = 360850 },
  74         { .temp_c       = -10, .ohm     = 271697 },
  75         { .temp_c       = -5, .ohm      = 206463 },
  76         { .temp_c       = 0, .ohm       = 158214 },
  77         { .temp_c       = 5, .ohm       = 122259 },
  78         { .temp_c       = 10, .ohm      = 95227 },
  79         { .temp_c       = 15, .ohm      = 74730 },
  80         { .temp_c       = 20, .ohm      = 59065 },
  81         { .temp_c       = 25, .ohm      = 47000 },
  82         { .temp_c       = 30, .ohm      = 37643 },
  83         { .temp_c       = 35, .ohm      = 30334 },
  84         { .temp_c       = 40, .ohm      = 24591 },
  85         { .temp_c       = 45, .ohm      = 20048 },
  86         { .temp_c       = 50, .ohm      = 16433 },
  87         { .temp_c       = 55, .ohm      = 13539 },
  88         { .temp_c       = 60, .ohm      = 11209 },
  89         { .temp_c       = 65, .ohm      = 9328 },
  90         { .temp_c       = 70, .ohm      = 7798 },
  91         { .temp_c       = 75, .ohm      = 6544 },
  92         { .temp_c       = 80, .ohm      = 5518 },
  93         { .temp_c       = 85, .ohm      = 4674 },
  94         { .temp_c       = 90, .ohm      = 3972 },
  95         { .temp_c       = 95, .ohm      = 3388 },
  96         { .temp_c       = 100, .ohm     = 2902 },
  97         { .temp_c       = 105, .ohm     = 2494 },
  98         { .temp_c       = 110, .ohm     = 2150 },
  99         { .temp_c       = 115, .ohm     = 1860 },
 100         { .temp_c       = 120, .ohm     = 1615 },
 101         { .temp_c       = 125, .ohm     = 1406 },
 102 };
 103 static const struct ntc_compensation ncpXXwl333[] = {
 104         { .temp_c       = -40, .ohm     = 1610154 },
 105         { .temp_c       = -35, .ohm     = 1130850 },
 106         { .temp_c       = -30, .ohm     = 802609 },
 107         { .temp_c       = -25, .ohm     = 575385 },
 108         { .temp_c       = -20, .ohm     = 416464 },
 109         { .temp_c       = -15, .ohm     = 304219 },
 110         { .temp_c       = -10, .ohm     = 224193 },
 111         { .temp_c       = -5, .ohm      = 166623 },
 112         { .temp_c       = 0, .ohm       = 124850 },
 113         { .temp_c       = 5, .ohm       = 94287 },
 114         { .temp_c       = 10, .ohm      = 71747 },
 115         { .temp_c       = 15, .ohm      = 54996 },
 116         { .temp_c       = 20, .ohm      = 42455 },
 117         { .temp_c       = 25, .ohm      = 33000 },
 118         { .temp_c       = 30, .ohm      = 25822 },
 119         { .temp_c       = 35, .ohm      = 20335 },
 120         { .temp_c       = 40, .ohm      = 16115 },
 121         { .temp_c       = 45, .ohm      = 12849 },
 122         { .temp_c       = 50, .ohm      = 10306 },
 123         { .temp_c       = 55, .ohm      = 8314 },
 124         { .temp_c       = 60, .ohm      = 6746 },
 125         { .temp_c       = 65, .ohm      = 5503 },
 126         { .temp_c       = 70, .ohm      = 4513 },
 127         { .temp_c       = 75, .ohm      = 3721 },
 128         { .temp_c       = 80, .ohm      = 3084 },
 129         { .temp_c       = 85, .ohm      = 2569 },
 130         { .temp_c       = 90, .ohm      = 2151 },
 131         { .temp_c       = 95, .ohm      = 1809 },
 132         { .temp_c       = 100, .ohm     = 1529 },
 133         { .temp_c       = 105, .ohm     = 1299 },
 134         { .temp_c       = 110, .ohm     = 1108 },
 135         { .temp_c       = 115, .ohm     = 949 },
 136         { .temp_c       = 120, .ohm     = 817 },
 137         { .temp_c       = 125, .ohm     = 707 },
 138 };
 139
 140 static const struct ntc_compensation ncpXXwf104[] = {
 141         { .temp_c       = -40, .ohm     = 4397119 },
 142         { .temp_c       = -35, .ohm     = 3088599 },
 143         { .temp_c       = -30, .ohm     = 2197225 },
 144         { .temp_c       = -25, .ohm     = 1581881 },
 145         { .temp_c       = -20, .ohm     = 1151037 },
 146         { .temp_c       = -15, .ohm     = 846579 },
 147         { .temp_c       = -10, .ohm     = 628988 },
 148         { .temp_c       = -5, .ohm      = 471632 },
 149         { .temp_c       = 0, .ohm       = 357012 },
 150         { .temp_c       = 5, .ohm       = 272500 },
 151         { .temp_c       = 10, .ohm      = 209710 },
 152         { .temp_c       = 15, .ohm      = 162651 },
 153         { .temp_c       = 20, .ohm      = 127080 },
 154         { .temp_c       = 25, .ohm      = 100000 },
 155         { .temp_c       = 30, .ohm      = 79222 },
 156         { .temp_c       = 35, .ohm      = 63167 },
 157         { .temp_c       = 40, .ohm      = 50677 },
 158         { .temp_c       = 45, .ohm      = 40904 },
 159         { .temp_c       = 50, .ohm      = 33195 },
 160         { .temp_c       = 55, .ohm      = 27091 },
 161         { .temp_c       = 60, .ohm      = 22224 },
 162         { .temp_c       = 65, .ohm      = 18323 },
 163         { .temp_c       = 70, .ohm      = 15184 },
 164         { .temp_c       = 75, .ohm      = 12635 },
 165         { .temp_c       = 80, .ohm      = 10566 },
 166         { .temp_c       = 85, .ohm      = 8873 },
 167         { .temp_c       = 90, .ohm      = 7481 },
 168         { .temp_c       = 95, .ohm      = 6337 },
 169         { .temp_c       = 100, .ohm     = 5384 },
 170         { .temp_c       = 105, .ohm     = 4594 },
 171         { .temp_c       = 110, .ohm     = 3934 },
 172         { .temp_c       = 115, .ohm     = 3380 },
 173         { .temp_c       = 120, .ohm     = 2916 },
 174         { .temp_c       = 125, .ohm     = 2522 },
 175 };
 176
 177 static const struct ntc_compensation ncpXXxh103[] = {
 178         { .temp_c       = -40, .ohm     = 247565 },
 179         { .temp_c       = -35, .ohm     = 181742 },
 180         { .temp_c       = -30, .ohm     = 135128 },
 181         { .temp_c       = -25, .ohm     = 101678 },
 182         { .temp_c       = -20, .ohm     = 77373 },
 183         { .temp_c       = -15, .ohm     = 59504 },
 184         { .temp_c       = -10, .ohm     = 46222 },
 185         { .temp_c       = -5, .ohm      = 36244 },
 186         { .temp_c       = 0, .ohm       = 28674 },
 187         { .temp_c       = 5, .ohm       = 22878 },
 188         { .temp_c       = 10, .ohm      = 18399 },
 189         { .temp_c       = 15, .ohm      = 14910 },
 190         { .temp_c       = 20, .ohm      = 12169 },
 191         { .temp_c       = 25, .ohm      = 10000 },
 192         { .temp_c       = 30, .ohm      = 8271 },
 193         { .temp_c       = 35, .ohm      = 6883 },
 194         { .temp_c       = 40, .ohm      = 5762 },
 195         { .temp_c       = 45, .ohm      = 4851 },
 196         { .temp_c       = 50, .ohm      = 4105 },
 197         { .temp_c       = 55, .ohm      = 3492 },
 198         { .temp_c       = 60, .ohm      = 2985 },
 199         { .temp_c       = 65, .ohm      = 2563 },
 200         { .temp_c       = 70, .ohm      = 2211 },
 201         { .temp_c       = 75, .ohm      = 1915 },
 202         { .temp_c       = 80, .ohm      = 1666 },
 203         { .temp_c       = 85, .ohm      = 1454 },
 204         { .temp_c       = 90, .ohm      = 1275 },
 205         { .temp_c       = 95, .ohm      = 1121 },
 206         { .temp_c       = 100, .ohm     = 990 },
 207         { .temp_c       = 105, .ohm     = 876 },
 208         { .temp_c       = 110, .ohm     = 779 },
 209         { .temp_c       = 115, .ohm     = 694 },
 210         { .temp_c       = 120, .ohm     = 620 },
 211         { .temp_c       = 125, .ohm     = 556 },
 212 };
 213
 214 /*
 215  * The following compensation table is from the specification of EPCOS NTC
 216  * Thermistors Datasheet
 217  */
 218 static const struct ntc_compensation b57330v2103[] = {
 219         { .temp_c       = -40, .ohm     = 190030 },
 220         { .temp_c       = -35, .ohm     = 145360 },
 221         { .temp_c       = -30, .ohm     = 112060 },
 222         { .temp_c       = -25, .ohm     = 87041 },
 223         { .temp_c       = -20, .ohm     = 68104 },
 224         { .temp_c       = -15, .ohm     = 53665 },
 225         { .temp_c       = -10, .ohm     = 42576 },
 226         { .temp_c       = -5, .ohm      = 34001 },
 227         { .temp_c       = 0, .ohm       = 27326 },
 228         { .temp_c       = 5, .ohm       = 22096 },
 229         { .temp_c       = 10, .ohm      = 17973 },
 230         { .temp_c       = 15, .ohm      = 14703 },
 231         { .temp_c       = 20, .ohm      = 12090 },
 232         { .temp_c       = 25, .ohm      = 10000 },
 233         { .temp_c       = 30, .ohm      = 8311 },
 234         { .temp_c       = 35, .ohm      = 6941 },
 235         { .temp_c       = 40, .ohm      = 5825 },
 236         { .temp_c       = 45, .ohm      = 4911 },
 237         { .temp_c       = 50, .ohm      = 4158 },
 238         { .temp_c       = 55, .ohm      = 3536 },
 239         { .temp_c       = 60, .ohm      = 3019 },
 240         { .temp_c       = 65, .ohm      = 2588 },
 241         { .temp_c       = 70, .ohm      = 2227 },
 242         { .temp_c       = 75, .ohm      = 1924 },
 243         { .temp_c       = 80, .ohm      = 1668 },
 244         { .temp_c       = 85, .ohm      = 1451 },
 245         { .temp_c       = 90, .ohm      = 1266 },
 246         { .temp_c       = 95, .ohm      = 1108 },
 247         { .temp_c       = 100, .ohm     = 973 },
 248         { .temp_c       = 105, .ohm     = 857 },
 249         { .temp_c       = 110, .ohm     = 757 },
 250         { .temp_c       = 115, .ohm     = 671 },
 251         { .temp_c       = 120, .ohm     = 596 },
 252         { .temp_c       = 125, .ohm     = 531 },
 253 };
 254
 255 struct ntc_data {
 256         struct device *hwmon_dev;
 257         struct ntc_thermistor_platform_data *pdata;
 258         const struct ntc_compensation *comp;
 259         struct device *dev;
 260         int n_comp;
 261         char name[PLATFORM_NAME_SIZE];
 262 };
 263
 264 #if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
 265 static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
 266 {
 267         struct iio_channel *channel = pdata->chan;
 268         int raw, uv, ret;
 269
 270         ret = iio_read_channel_raw(channel, &raw);
 271         if (ret < 0) {
 272                 pr_err("read channel() error: %d\n", ret);
 273                 return ret;
 274         }
 275
 276         ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000);
 277         if (ret < 0) {
 278                 /* Assume 12 bit ADC with vref at pullup_uv */
 279                 uv = (pdata->pullup_uv * (s64)raw) >> 12;
 280         }
 281
 282         return uv;
 283 }
 284
 285 static const struct of_device_id ntc_match[] = {
 286         { .compatible = "murata,ncp15wb473",
 287                 .data = &ntc_thermistor_id[0] },
 288         { .compatible = "murata,ncp18wb473",
 289                 .data = &ntc_thermistor_id[1] },
 290         { .compatible = "murata,ncp21wb473",
 291                 .data = &ntc_thermistor_id[2] },
 292         { .compatible = "murata,ncp03wb473",
 293                 .data = &ntc_thermistor_id[3] },
 294         { .compatible = "murata,ncp15wl333",
 295                 .data = &ntc_thermistor_id[4] },
 296         { .compatible = "epcos,b57330v2103",
 297                 .data = &ntc_thermistor_id[5]},
 298         { .compatible = "murata,ncp03wf104",
 299                 .data = &ntc_thermistor_id[6] },
 300         { .compatible = "murata,ncp15xh103",
 301                 .data = &ntc_thermistor_id[7] },
 302
 303         /* Usage of vendor name "ntc" is deprecated */
 304         { .compatible = "ntc,ncp15wb473",
 305                 .data = &ntc_thermistor_id[0] },
 306         { .compatible = "ntc,ncp18wb473",
 307                 .data = &ntc_thermistor_id[1] },
 308         { .compatible = "ntc,ncp21wb473",
 309                 .data = &ntc_thermistor_id[2] },
 310         { .compatible = "ntc,ncp03wb473",
 311                 .data = &ntc_thermistor_id[3] },
 312         { .compatible = "ntc,ncp15wl333",
 313                 .data = &ntc_thermistor_id[4] },
 314         { },
 315 };
 316 MODULE_DEVICE_TABLE(of, ntc_match);
 317
 318 static struct ntc_thermistor_platform_data *
 319 ntc_thermistor_parse_dt(struct platform_device *pdev)
 320 {
 321         struct iio_channel *chan;
 322         enum iio_chan_type type;
 323         struct device_node *np = pdev->dev.of_node;
 324         struct ntc_thermistor_platform_data *pdata;
 325         int ret;
 326
 327         if (!np)
 328                 return NULL;
 329
 330         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 331         if (!pdata)
 332                 return ERR_PTR(-ENOMEM);
 333
 334         chan = iio_channel_get(&pdev->dev, NULL);
 335         if (IS_ERR(chan))
 336                 return ERR_CAST(chan);
 337
 338         ret = iio_get_channel_type(chan, &type);
 339         if (ret < 0)
 340                 return ERR_PTR(ret);
 341
 342         if (type != IIO_VOLTAGE)
 343                 return ERR_PTR(-EINVAL);
 344
 345         if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
 346                 return ERR_PTR(-ENODEV);
 347         if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
 348                 return ERR_PTR(-ENODEV);
 349         if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
 350                 return ERR_PTR(-ENODEV);
 351
 352         if (of_find_property(np, "connected-positive", NULL))
 353                 pdata->connect = NTC_CONNECTED_POSITIVE;
 354         else /* status change should be possible if not always on. */
 355                 pdata->connect = NTC_CONNECTED_GROUND;
 356
 357         pdata->chan = chan;
 358         pdata->read_uv = ntc_adc_iio_read;
 359
 360         return pdata;
 361 }
 362 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
 363 {
 364         if (pdata->chan)
 365                 iio_channel_release(pdata->chan);
 366 }
 367 #else
 368 static struct ntc_thermistor_platform_data *
 369 ntc_thermistor_parse_dt(struct platform_device *pdev)
 370 {
 371         return NULL;
 372 }
 373
 374 #define ntc_match       NULL
 375
 376 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
 377 { }
 378 #endif
 379
 380 static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
 381 {
 382         if (divisor == 0 && dividend == 0)
 383                 return 0;
 384         if (divisor == 0)
 385                 return UINT_MAX;
 386         return div64_u64(dividend, divisor);
 387 }
 388
 389 static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv)
 390 {
 391         struct ntc_thermistor_platform_data *pdata = data->pdata;
 392         u32 puv = pdata->pullup_uv;
 393         u64 n, puo, pdo;
 394         puo = pdata->pullup_ohm;
 395         pdo = pdata->pulldown_ohm;
 396
 397         if (uv == 0)
 398                 return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
 399                         INT_MAX : 0;
 400         if (uv >= puv)
 401                 return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
 402                         0 : INT_MAX;
 403
 404         if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
 405                 n = div_u64(pdo * (puv - uv), uv);
 406         else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
 407                 n = div_u64(puo * uv, puv - uv);
 408         else if (pdata->connect == NTC_CONNECTED_POSITIVE)
 409                 n = div64_u64_safe(pdo * puo * (puv - uv),
 410                                 puo * uv - pdo * (puv - uv));
 411         else
 412                 n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv);
 413
 414         if (n > INT_MAX)
 415                 n = INT_MAX;
 416         return n;
 417 }
 418
 419 static void lookup_comp(struct ntc_data *data, unsigned int ohm,
 420                         int *i_low, int *i_high)
 421 {
 422         int start, end, mid;
 423
 424         /*
 425          * Handle special cases: Resistance is higher than or equal to
 426          * resistance in first table entry, or resistance is lower or equal
 427          * to resistance in last table entry.
 428          * In these cases, return i_low == i_high, either pointing to the
 429          * beginning or to the end of the table depending on the condition.
 430          */
 431         if (ohm >= data->comp[0].ohm) {
 432                 *i_low = 0;
 433                 *i_high = 0;
 434                 return;
 435         }
 436         if (ohm <= data->comp[data->n_comp - 1].ohm) {
 437                 *i_low = data->n_comp - 1;
 438                 *i_high = data->n_comp - 1;
 439                 return;
 440         }
 441
 442         /* Do a binary search on compensation table */
 443         start = 0;
 444         end = data->n_comp;
 445         while (start < end) {
 446                 mid = start + (end - start) / 2;
 447                 /*
 448                  * start <= mid < end
 449                  * data->comp[start].ohm > ohm >= data->comp[end].ohm
 450                  *
 451                  * We could check for "ohm == data->comp[mid].ohm" here, but
 452                  * that is a quite unlikely condition, and we would have to
 453                  * check again after updating start. Check it at the end instead
 454                  * for simplicity.
 455                  */
 456                 if (ohm >= data->comp[mid].ohm) {
 457                         end = mid;
 458                 } else {
 459                         start = mid + 1;
 460                         /*
 461                          * ohm >= data->comp[start].ohm might be true here,
 462                          * since we set start to mid + 1. In that case, we are
 463                          * done. We could keep going, but the condition is quite
 464                          * likely to occur, so it is worth checking for it.
 465                          */
 466                         if (ohm >= data->comp[start].ohm)
 467                                 end = start;
 468                 }
 469                 /*
 470                  * start <= end
 471                  * data->comp[start].ohm >= ohm >= data->comp[end].ohm
 472                  */
 473         }
 474         /*
 475          * start == end
 476          * ohm >= data->comp[end].ohm
 477          */
 478         *i_low = end;
 479         if (ohm == data->comp[end].ohm)
 480                 *i_high = end;
 481         else
 482                 *i_high = end - 1;
 483 }
 484
 485 static int get_temp_mc(struct ntc_data *data, unsigned int ohm)
 486 {
 487         int low, high;
 488         int temp;
 489
 490         lookup_comp(data, ohm, &low, &high);
 491         if (low == high) {
 492                 /* Unable to use linear approximation */
 493                 temp = data->comp[low].temp_c * 1000;
 494         } else {
 495                 temp = data->comp[low].temp_c * 1000 +
 496                         ((data->comp[high].temp_c - data->comp[low].temp_c) *
 497                          1000 * ((int)ohm - (int)data->comp[low].ohm)) /
 498                         ((int)data->comp[high].ohm - (int)data->comp[low].ohm);
 499         }
 500         return temp;
 501 }
 502
 503 static int ntc_thermistor_get_ohm(struct ntc_data *data)
 504 {
 505         int read_uv;
 506
 507         if (data->pdata->read_ohm)
 508                 return data->pdata->read_ohm();
 509
 510         if (data->pdata->read_uv) {
 511                 read_uv = data->pdata->read_uv(data->pdata);
 512                 if (read_uv < 0)
 513                         return read_uv;
 514                 return get_ohm_of_thermistor(data, read_uv);
 515         }
 516         return -EINVAL;
 517 }
 518
 519 static int ntc_read_temp(void *dev, int *temp)
 520 {
 521         struct ntc_data *data = dev_get_drvdata(dev);
 522         int ohm;
 523
 524         ohm = ntc_thermistor_get_ohm(data);
 525         if (ohm < 0)
 526                 return ohm;
 527
 528         *temp = get_temp_mc(data, ohm);
 529
 530         return 0;
 531 }
 532
 533 static ssize_t ntc_show_name(struct device *dev,
 534                 struct device_attribute *attr, char *buf)
 535 {
 536         struct ntc_data *data = dev_get_drvdata(dev);
 537
 538         return sprintf(buf, "%s\n", data->name);
 539 }
 540
 541 static ssize_t ntc_show_type(struct device *dev,
 542                 struct device_attribute *attr, char *buf)
 543 {
 544         return sprintf(buf, "4\n");
 545 }
 546
 547 static ssize_t ntc_show_temp(struct device *dev,
 548                 struct device_attribute *attr, char *buf)
 549 {
 550         struct ntc_data *data = dev_get_drvdata(dev);
 551         int ohm;
 552
 553         ohm = ntc_thermistor_get_ohm(data);
 554         if (ohm < 0)
 555                 return ohm;
 556
 557         return sprintf(buf, "%d\n", get_temp_mc(data, ohm));
 558 }
 559
 560 static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0);
 561 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0);
 562 static DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL);
 563
 564 static struct attribute *ntc_attributes[] = {
 565         &dev_attr_name.attr,
 566         &sensor_dev_attr_temp1_type.dev_attr.attr,
 567         &sensor_dev_attr_temp1_input.dev_attr.attr,
 568         NULL,
 569 };
 570
 571 static const struct attribute_group ntc_attr_group = {
 572         .attrs = ntc_attributes,
 573 };
 574
 575 static const struct thermal_zone_of_device_ops ntc_of_thermal_ops = {
 576         .get_temp = ntc_read_temp,
 577 };
 578
 579 static int ntc_thermistor_probe(struct platform_device *pdev)
 580 {
 581         struct thermal_zone_device *tz;
 582         const struct of_device_id *of_id =
 583                         of_match_device(of_match_ptr(ntc_match), &pdev->dev);
 584         const struct platform_device_id *pdev_id;
 585         struct ntc_thermistor_platform_data *pdata;
 586         struct ntc_data *data;
 587         int ret;
 588
 589         pdata = ntc_thermistor_parse_dt(pdev);
 590         if (IS_ERR(pdata))
 591                 return PTR_ERR(pdata);
 592         else if (pdata == NULL)
 593                 pdata = dev_get_platdata(&pdev->dev);
 594
 595         if (!pdata) {
 596                 dev_err(&pdev->dev, "No platform init data supplied.\n");
 597                 return -ENODEV;
 598         }
 599
 600         /* Either one of the two is required. */
 601         if (!pdata->read_uv && !pdata->read_ohm) {
 602                 dev_err(&pdev->dev,
 603                         "Both read_uv and read_ohm missing. Need either one of the two.\n");
 604                 return -EINVAL;
 605         }
 606
 607         if (pdata->read_uv && pdata->read_ohm) {
 608                 dev_warn(&pdev->dev,
 609                          "Only one of read_uv and read_ohm is needed; ignoring read_uv.\n");
 610                 pdata->read_uv = NULL;
 611         }
 612
 613         if (pdata->read_uv && (pdata->pullup_uv == 0 ||
 614                                 (pdata->pullup_ohm == 0 && pdata->connect ==
 615                                  NTC_CONNECTED_GROUND) ||
 616                                 (pdata->pulldown_ohm == 0 && pdata->connect ==
 617                                  NTC_CONNECTED_POSITIVE) ||
 618                                 (pdata->connect != NTC_CONNECTED_POSITIVE &&
 619                                  pdata->connect != NTC_CONNECTED_GROUND))) {
 620                 dev_err(&pdev->dev,
 621                         "Required data to use read_uv not supplied.\n");
 622                 return -EINVAL;
 623         }
 624
 625         data = devm_kzalloc(&pdev->dev, sizeof(struct ntc_data), GFP_KERNEL);
 626         if (!data)
 627                 return -ENOMEM;
 628
 629         pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
 630
 631         data->dev = &pdev->dev;
 632         data->pdata = pdata;
 633         strlcpy(data->name, pdev_id->name, sizeof(data->name));
 634
 635         switch (pdev_id->driver_data) {
 636         case TYPE_NCPXXWB473:
 637                 data->comp = ncpXXwb473;
 638                 data->n_comp = ARRAY_SIZE(ncpXXwb473);
 639                 break;
 640         case TYPE_NCPXXWL333:
 641                 data->comp = ncpXXwl333;
 642                 data->n_comp = ARRAY_SIZE(ncpXXwl333);
 643                 break;
 644         case TYPE_B57330V2103:
 645                 data->comp = b57330v2103;
 646                 data->n_comp = ARRAY_SIZE(b57330v2103);
 647                 break;
 648         case TYPE_NCPXXWF104:
 649                 data->comp = ncpXXwf104;
 650                 data->n_comp = ARRAY_SIZE(ncpXXwf104);
 651                 break;
 652         case TYPE_NCPXXXH103:
 653                 data->comp = ncpXXxh103;
 654                 data->n_comp = ARRAY_SIZE(ncpXXxh103);
 655                 break;
 656         default:
 657                 dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
 658                                 pdev_id->driver_data, pdev_id->name);
 659                 return -EINVAL;
 660         }
 661
 662         platform_set_drvdata(pdev, data);
 663
 664         ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group);
 665         if (ret) {
 666                 dev_err(data->dev, "unable to create sysfs files\n");
 667                 return ret;
 668         }
 669
 670         data->hwmon_dev = hwmon_device_register(data->dev);
 671         if (IS_ERR(data->hwmon_dev)) {
 672                 dev_err(data->dev, "unable to register as hwmon device.\n");
 673                 ret = PTR_ERR(data->hwmon_dev);
 674                 goto err_after_sysfs;
 675         }
 676
 677         dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
 678                                                                 pdev_id->name);
 679
 680         tz = devm_thermal_zone_of_sensor_register(data->dev, 0, data->dev,
 681                                                   &ntc_of_thermal_ops);
 682         if (IS_ERR(tz))
 683                 dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n");
 684
 685         return 0;
 686 err_after_sysfs:
 687         sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
 688         ntc_iio_channel_release(pdata);
 689         return ret;
 690 }
 691
 692 static int ntc_thermistor_remove(struct platform_device *pdev)
 693 {
 694         struct ntc_data *data = platform_get_drvdata(pdev);
 695         struct ntc_thermistor_platform_data *pdata = data->pdata;
 696
 697         hwmon_device_unregister(data->hwmon_dev);
 698         sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
 699         ntc_iio_channel_release(pdata);
 700
 701         return 0;
 702 }
 703
 704 static struct platform_driver ntc_thermistor_driver = {
 705         .driver = {
 706                 .name = "ntc-thermistor",
 707                 .of_match_table = of_match_ptr(ntc_match),
 708         },
 709         .probe = ntc_thermistor_probe,
 710         .remove = ntc_thermistor_remove,
 711         .id_table = ntc_thermistor_id,
 712 };
 713
 714 module_platform_driver(ntc_thermistor_driver);
 715
 716 MODULE_DESCRIPTION("NTC Thermistor Driver");
 717 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 718 MODULE_LICENSE("GPL");
 719 MODULE_ALIAS("platform:ntc-thermistor");