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)
ntc_adc_iio_read(struct ntc_thermistor_platform_data * pdata)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 *
ntc_thermistor_parse_dt(struct platform_device * pdev)239 ntc_thermistor_parse_dt(struct platform_device *pdev)
240 {
241 struct iio_channel *chan;
242 enum iio_chan_type type;
243 struct device_node *np = pdev->dev.of_node;
244 struct ntc_thermistor_platform_data *pdata;
245 int ret;
246
247 if (!np)
248 return NULL;
249
250 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
251 if (!pdata)
252 return ERR_PTR(-ENOMEM);
253
254 chan = iio_channel_get(&pdev->dev, NULL);
255 if (IS_ERR(chan))
256 return ERR_CAST(chan);
257
258 ret = iio_get_channel_type(chan, &type);
259 if (ret < 0)
260 return ERR_PTR(ret);
261
262 if (type != IIO_VOLTAGE)
263 return ERR_PTR(-EINVAL);
264
265 if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
266 return ERR_PTR(-ENODEV);
267 if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
268 return ERR_PTR(-ENODEV);
269 if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
270 return ERR_PTR(-ENODEV);
271
272 if (of_find_property(np, "connected-positive", NULL))
273 pdata->connect = NTC_CONNECTED_POSITIVE;
274 else /* status change should be possible if not always on. */
275 pdata->connect = NTC_CONNECTED_GROUND;
276
277 pdata->chan = chan;
278 pdata->read_uv = ntc_adc_iio_read;
279
280 return pdata;
281 }
ntc_iio_channel_release(struct ntc_thermistor_platform_data * pdata)282 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
283 {
284 if (pdata->chan)
285 iio_channel_release(pdata->chan);
286 }
287 #else
288 static struct ntc_thermistor_platform_data *
ntc_thermistor_parse_dt(struct platform_device * pdev)289 ntc_thermistor_parse_dt(struct platform_device *pdev)
290 {
291 return NULL;
292 }
293
294 #define ntc_match NULL
295
ntc_iio_channel_release(struct ntc_thermistor_platform_data * pdata)296 static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
297 { }
298 #endif
299
div64_u64_safe(u64 dividend,u64 divisor)300 static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
301 {
302 if (divisor == 0 && dividend == 0)
303 return 0;
304 if (divisor == 0)
305 return UINT_MAX;
306 return div64_u64(dividend, divisor);
307 }
308
get_ohm_of_thermistor(struct ntc_data * data,unsigned int uv)309 static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv)
310 {
311 struct ntc_thermistor_platform_data *pdata = data->pdata;
312 u64 mv = uv / 1000;
313 u64 pmv = pdata->pullup_uv / 1000;
314 u64 n, puo, pdo;
315 puo = pdata->pullup_ohm;
316 pdo = pdata->pulldown_ohm;
317
318 if (mv == 0) {
319 if (pdata->connect == NTC_CONNECTED_POSITIVE)
320 return INT_MAX;
321 return 0;
322 }
323 if (mv >= pmv)
324 return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
325 0 : INT_MAX;
326
327 if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
328 n = div64_u64_safe(pdo * (pmv - mv), mv);
329 else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
330 n = div64_u64_safe(puo * mv, pmv - mv);
331 else if (pdata->connect == NTC_CONNECTED_POSITIVE)
332 n = div64_u64_safe(pdo * puo * (pmv - mv),
333 puo * mv - pdo * (pmv - mv));
334 else
335 n = div64_u64_safe(pdo * puo * mv, pdo * (pmv - mv) - puo * mv);
336
337 if (n > INT_MAX)
338 n = INT_MAX;
339 return n;
340 }
341
lookup_comp(struct ntc_data * data,unsigned int ohm,int * i_low,int * i_high)342 static void lookup_comp(struct ntc_data *data, unsigned int ohm,
343 int *i_low, int *i_high)
344 {
345 int start, end, mid;
346
347 /*
348 * Handle special cases: Resistance is higher than or equal to
349 * resistance in first table entry, or resistance is lower or equal
350 * to resistance in last table entry.
351 * In these cases, return i_low == i_high, either pointing to the
352 * beginning or to the end of the table depending on the condition.
353 */
354 if (ohm >= data->comp[0].ohm) {
355 *i_low = 0;
356 *i_high = 0;
357 return;
358 }
359 if (ohm <= data->comp[data->n_comp - 1].ohm) {
360 *i_low = data->n_comp - 1;
361 *i_high = data->n_comp - 1;
362 return;
363 }
364
365 /* Do a binary search on compensation table */
366 start = 0;
367 end = data->n_comp;
368 while (start < end) {
369 mid = start + (end - start) / 2;
370 /*
371 * start <= mid < end
372 * data->comp[start].ohm > ohm >= data->comp[end].ohm
373 *
374 * We could check for "ohm == data->comp[mid].ohm" here, but
375 * that is a quite unlikely condition, and we would have to
376 * check again after updating start. Check it at the end instead
377 * for simplicity.
378 */
379 if (ohm >= data->comp[mid].ohm) {
380 end = mid;
381 } else {
382 start = mid + 1;
383 /*
384 * ohm >= data->comp[start].ohm might be true here,
385 * since we set start to mid + 1. In that case, we are
386 * done. We could keep going, but the condition is quite
387 * likely to occur, so it is worth checking for it.
388 */
389 if (ohm >= data->comp[start].ohm)
390 end = start;
391 }
392 /*
393 * start <= end
394 * data->comp[start].ohm >= ohm >= data->comp[end].ohm
395 */
396 }
397 /*
398 * start == end
399 * ohm >= data->comp[end].ohm
400 */
401 *i_low = end;
402 if (ohm == data->comp[end].ohm)
403 *i_high = end;
404 else
405 *i_high = end - 1;
406 }
407
get_temp_mc(struct ntc_data * data,unsigned int ohm)408 static int get_temp_mc(struct ntc_data *data, unsigned int ohm)
409 {
410 int low, high;
411 int temp;
412
413 lookup_comp(data, ohm, &low, &high);
414 if (low == high) {
415 /* Unable to use linear approximation */
416 temp = data->comp[low].temp_c * 1000;
417 } else {
418 temp = data->comp[low].temp_c * 1000 +
419 ((data->comp[high].temp_c - data->comp[low].temp_c) *
420 1000 * ((int)ohm - (int)data->comp[low].ohm)) /
421 ((int)data->comp[high].ohm - (int)data->comp[low].ohm);
422 }
423 return temp;
424 }
425
ntc_thermistor_get_ohm(struct ntc_data * data)426 static int ntc_thermistor_get_ohm(struct ntc_data *data)
427 {
428 int read_uv;
429
430 if (data->pdata->read_ohm)
431 return data->pdata->read_ohm();
432
433 if (data->pdata->read_uv) {
434 read_uv = data->pdata->read_uv(data->pdata);
435 if (read_uv < 0)
436 return read_uv;
437 return get_ohm_of_thermistor(data, read_uv);
438 }
439 return -EINVAL;
440 }
441
ntc_read_temp(void * dev,long * temp)442 static int ntc_read_temp(void *dev, long *temp)
443 {
444 struct ntc_data *data = dev_get_drvdata(dev);
445 int ohm;
446
447 ohm = ntc_thermistor_get_ohm(data);
448 if (ohm < 0)
449 return ohm;
450
451 *temp = get_temp_mc(data, ohm);
452
453 return 0;
454 }
455
ntc_show_name(struct device * dev,struct device_attribute * attr,char * buf)456 static ssize_t ntc_show_name(struct device *dev,
457 struct device_attribute *attr, char *buf)
458 {
459 struct ntc_data *data = dev_get_drvdata(dev);
460
461 return sprintf(buf, "%s\n", data->name);
462 }
463
ntc_show_type(struct device * dev,struct device_attribute * attr,char * buf)464 static ssize_t ntc_show_type(struct device *dev,
465 struct device_attribute *attr, char *buf)
466 {
467 return sprintf(buf, "4\n");
468 }
469
ntc_show_temp(struct device * dev,struct device_attribute * attr,char * buf)470 static ssize_t ntc_show_temp(struct device *dev,
471 struct device_attribute *attr, char *buf)
472 {
473 struct ntc_data *data = dev_get_drvdata(dev);
474 int ohm;
475
476 ohm = ntc_thermistor_get_ohm(data);
477 if (ohm < 0)
478 return ohm;
479
480 return sprintf(buf, "%d\n", get_temp_mc(data, ohm));
481 }
482
483 static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0);
484 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0);
485 static DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL);
486
487 static struct attribute *ntc_attributes[] = {
488 &dev_attr_name.attr,
489 &sensor_dev_attr_temp1_type.dev_attr.attr,
490 &sensor_dev_attr_temp1_input.dev_attr.attr,
491 NULL,
492 };
493
494 static const struct attribute_group ntc_attr_group = {
495 .attrs = ntc_attributes,
496 };
497
ntc_thermistor_probe(struct platform_device * pdev)498 static int ntc_thermistor_probe(struct platform_device *pdev)
499 {
500 const struct of_device_id *of_id =
501 of_match_device(of_match_ptr(ntc_match), &pdev->dev);
502 const struct platform_device_id *pdev_id;
503 struct ntc_thermistor_platform_data *pdata;
504 struct ntc_data *data;
505 int ret;
506
507 pdata = ntc_thermistor_parse_dt(pdev);
508 if (IS_ERR(pdata))
509 return PTR_ERR(pdata);
510 else if (pdata == NULL)
511 pdata = dev_get_platdata(&pdev->dev);
512
513 if (!pdata) {
514 dev_err(&pdev->dev, "No platform init data supplied.\n");
515 return -ENODEV;
516 }
517
518 /* Either one of the two is required. */
519 if (!pdata->read_uv && !pdata->read_ohm) {
520 dev_err(&pdev->dev,
521 "Both read_uv and read_ohm missing. Need either one of the two.\n");
522 return -EINVAL;
523 }
524
525 if (pdata->read_uv && pdata->read_ohm) {
526 dev_warn(&pdev->dev,
527 "Only one of read_uv and read_ohm is needed; ignoring read_uv.\n");
528 pdata->read_uv = NULL;
529 }
530
531 if (pdata->read_uv && (pdata->pullup_uv == 0 ||
532 (pdata->pullup_ohm == 0 && pdata->connect ==
533 NTC_CONNECTED_GROUND) ||
534 (pdata->pulldown_ohm == 0 && pdata->connect ==
535 NTC_CONNECTED_POSITIVE) ||
536 (pdata->connect != NTC_CONNECTED_POSITIVE &&
537 pdata->connect != NTC_CONNECTED_GROUND))) {
538 dev_err(&pdev->dev,
539 "Required data to use read_uv not supplied.\n");
540 return -EINVAL;
541 }
542
543 data = devm_kzalloc(&pdev->dev, sizeof(struct ntc_data), GFP_KERNEL);
544 if (!data)
545 return -ENOMEM;
546
547 pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
548
549 data->dev = &pdev->dev;
550 data->pdata = pdata;
551 strlcpy(data->name, pdev_id->name, sizeof(data->name));
552
553 switch (pdev_id->driver_data) {
554 case TYPE_NCPXXWB473:
555 data->comp = ncpXXwb473;
556 data->n_comp = ARRAY_SIZE(ncpXXwb473);
557 break;
558 case TYPE_NCPXXWL333:
559 data->comp = ncpXXwl333;
560 data->n_comp = ARRAY_SIZE(ncpXXwl333);
561 break;
562 case TYPE_B57330V2103:
563 data->comp = b57330v2103;
564 data->n_comp = ARRAY_SIZE(b57330v2103);
565 break;
566 default:
567 dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
568 pdev_id->driver_data, pdev_id->name);
569 return -EINVAL;
570 }
571
572 platform_set_drvdata(pdev, data);
573
574 ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group);
575 if (ret) {
576 dev_err(data->dev, "unable to create sysfs files\n");
577 return ret;
578 }
579
580 data->hwmon_dev = hwmon_device_register(data->dev);
581 if (IS_ERR(data->hwmon_dev)) {
582 dev_err(data->dev, "unable to register as hwmon device.\n");
583 ret = PTR_ERR(data->hwmon_dev);
584 goto err_after_sysfs;
585 }
586
587 dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
588 pdev_id->name);
589
590 data->tz = thermal_zone_of_sensor_register(data->dev, 0, data->dev,
591 ntc_read_temp, NULL);
592 if (IS_ERR(data->tz)) {
593 dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n");
594 data->tz = NULL;
595 }
596
597 return 0;
598 err_after_sysfs:
599 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
600 ntc_iio_channel_release(pdata);
601 return ret;
602 }
603
ntc_thermistor_remove(struct platform_device * pdev)604 static int ntc_thermistor_remove(struct platform_device *pdev)
605 {
606 struct ntc_data *data = platform_get_drvdata(pdev);
607 struct ntc_thermistor_platform_data *pdata = data->pdata;
608
609 hwmon_device_unregister(data->hwmon_dev);
610 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
611 ntc_iio_channel_release(pdata);
612
613 thermal_zone_of_sensor_unregister(data->dev, data->tz);
614
615 return 0;
616 }
617
618 static struct platform_driver ntc_thermistor_driver = {
619 .driver = {
620 .name = "ntc-thermistor",
621 .owner = THIS_MODULE,
622 .of_match_table = of_match_ptr(ntc_match),
623 },
624 .probe = ntc_thermistor_probe,
625 .remove = ntc_thermistor_remove,
626 .id_table = ntc_thermistor_id,
627 };
628
629 module_platform_driver(ntc_thermistor_driver);
630
631 MODULE_DESCRIPTION("NTC Thermistor Driver");
632 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
633 MODULE_LICENSE("GPL");
634 MODULE_ALIAS("platform:ntc-thermistor");
635