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
 43struct ntc_compensation {
 44	int		temp_c;
 45	unsigned int	ohm;
 46};
 47
 48/* Order matters, ntc_match references the entries by index */
 49static 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 */
 67static 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};
103static 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
140static 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
177static 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 */
218static 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
255struct ntc_data {
256	struct ntc_thermistor_platform_data *pdata;
257	const struct ntc_compensation *comp;
258	int n_comp;
259};
260
261#if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
262static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
263{
264	struct iio_channel *channel = pdata->chan;
265	int raw, uv, ret;
266
267	ret = iio_read_channel_raw(channel, &raw);
268	if (ret < 0) {
269		pr_err("read channel() error: %d\n", ret);
270		return ret;
271	}
272
273	ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000);
274	if (ret < 0) {
275		/* Assume 12 bit ADC with vref at pullup_uv */
276		uv = (pdata->pullup_uv * (s64)raw) >> 12;
277	}
278
279	return uv;
280}
281
282static const struct of_device_id ntc_match[] = {
283	{ .compatible = "murata,ncp15wb473",
284		.data = &ntc_thermistor_id[0] },
285	{ .compatible = "murata,ncp18wb473",
286		.data = &ntc_thermistor_id[1] },
287	{ .compatible = "murata,ncp21wb473",
288		.data = &ntc_thermistor_id[2] },
289	{ .compatible = "murata,ncp03wb473",
290		.data = &ntc_thermistor_id[3] },
291	{ .compatible = "murata,ncp15wl333",
292		.data = &ntc_thermistor_id[4] },
293	{ .compatible = "epcos,b57330v2103",
294		.data = &ntc_thermistor_id[5]},
295	{ .compatible = "murata,ncp03wf104",
296		.data = &ntc_thermistor_id[6] },
297	{ .compatible = "murata,ncp15xh103",
298		.data = &ntc_thermistor_id[7] },
299
300	/* Usage of vendor name "ntc" is deprecated */
301	{ .compatible = "ntc,ncp15wb473",
302		.data = &ntc_thermistor_id[0] },
303	{ .compatible = "ntc,ncp18wb473",
304		.data = &ntc_thermistor_id[1] },
305	{ .compatible = "ntc,ncp21wb473",
306		.data = &ntc_thermistor_id[2] },
307	{ .compatible = "ntc,ncp03wb473",
308		.data = &ntc_thermistor_id[3] },
309	{ .compatible = "ntc,ncp15wl333",
310		.data = &ntc_thermistor_id[4] },
311	{ },
312};
313MODULE_DEVICE_TABLE(of, ntc_match);
314
315static struct ntc_thermistor_platform_data *
316ntc_thermistor_parse_dt(struct device *dev)
317{
318	struct iio_channel *chan;
319	enum iio_chan_type type;
320	struct device_node *np = dev->of_node;
321	struct ntc_thermistor_platform_data *pdata;
322	int ret;
323
324	if (!np)
325		return NULL;
326
327	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
328	if (!pdata)
329		return ERR_PTR(-ENOMEM);
330
331	chan = devm_iio_channel_get(dev, NULL);
332	if (IS_ERR(chan))
333		return ERR_CAST(chan);
334
335	ret = iio_get_channel_type(chan, &type);
336	if (ret < 0)
337		return ERR_PTR(ret);
338
339	if (type != IIO_VOLTAGE)
340		return ERR_PTR(-EINVAL);
341
342	if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
343		return ERR_PTR(-ENODEV);
344	if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
345		return ERR_PTR(-ENODEV);
346	if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
347		return ERR_PTR(-ENODEV);
348
349	if (of_find_property(np, "connected-positive", NULL))
350		pdata->connect = NTC_CONNECTED_POSITIVE;
351	else /* status change should be possible if not always on. */
352		pdata->connect = NTC_CONNECTED_GROUND;
353
354	pdata->chan = chan;
355	pdata->read_uv = ntc_adc_iio_read;
356
357	return pdata;
358}
359#else
360static struct ntc_thermistor_platform_data *
361ntc_thermistor_parse_dt(struct device *dev)
362{
363	return NULL;
364}
365
366#define ntc_match	NULL
367
368#endif
369
370static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
371{
372	if (divisor == 0 && dividend == 0)
373		return 0;
374	if (divisor == 0)
375		return UINT_MAX;
376	return div64_u64(dividend, divisor);
377}
378
379static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv)
380{
381	struct ntc_thermistor_platform_data *pdata = data->pdata;
382	u32 puv = pdata->pullup_uv;
383	u64 n, puo, pdo;
384	puo = pdata->pullup_ohm;
385	pdo = pdata->pulldown_ohm;
386
387	if (uv == 0)
388		return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
389			INT_MAX : 0;
390	if (uv >= puv)
391		return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
392			0 : INT_MAX;
393
394	if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
395		n = div_u64(pdo * (puv - uv), uv);
396	else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
397		n = div_u64(puo * uv, puv - uv);
398	else if (pdata->connect == NTC_CONNECTED_POSITIVE)
399		n = div64_u64_safe(pdo * puo * (puv - uv),
400				puo * uv - pdo * (puv - uv));
401	else
402		n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv);
403
404	if (n > INT_MAX)
405		n = INT_MAX;
406	return n;
407}
408
409static void lookup_comp(struct ntc_data *data, unsigned int ohm,
410			int *i_low, int *i_high)
411{
412	int start, end, mid;
413
414	/*
415	 * Handle special cases: Resistance is higher than or equal to
416	 * resistance in first table entry, or resistance is lower or equal
417	 * to resistance in last table entry.
418	 * In these cases, return i_low == i_high, either pointing to the
419	 * beginning or to the end of the table depending on the condition.
420	 */
421	if (ohm >= data->comp[0].ohm) {
422		*i_low = 0;
423		*i_high = 0;
424		return;
425	}
426	if (ohm <= data->comp[data->n_comp - 1].ohm) {
427		*i_low = data->n_comp - 1;
428		*i_high = data->n_comp - 1;
429		return;
430	}
431
432	/* Do a binary search on compensation table */
433	start = 0;
434	end = data->n_comp;
435	while (start < end) {
436		mid = start + (end - start) / 2;
437		/*
438		 * start <= mid < end
439		 * data->comp[start].ohm > ohm >= data->comp[end].ohm
440		 *
441		 * We could check for "ohm == data->comp[mid].ohm" here, but
442		 * that is a quite unlikely condition, and we would have to
443		 * check again after updating start. Check it at the end instead
444		 * for simplicity.
445		 */
446		if (ohm >= data->comp[mid].ohm) {
447			end = mid;
448		} else {
449			start = mid + 1;
450			/*
451			 * ohm >= data->comp[start].ohm might be true here,
452			 * since we set start to mid + 1. In that case, we are
453			 * done. We could keep going, but the condition is quite
454			 * likely to occur, so it is worth checking for it.
455			 */
456			if (ohm >= data->comp[start].ohm)
457				end = start;
458		}
459		/*
460		 * start <= end
461		 * data->comp[start].ohm >= ohm >= data->comp[end].ohm
462		 */
463	}
464	/*
465	 * start == end
466	 * ohm >= data->comp[end].ohm
467	 */
468	*i_low = end;
469	if (ohm == data->comp[end].ohm)
470		*i_high = end;
471	else
472		*i_high = end - 1;
473}
474
475static int get_temp_mc(struct ntc_data *data, unsigned int ohm)
476{
477	int low, high;
478	int temp;
479
480	lookup_comp(data, ohm, &low, &high);
481	if (low == high) {
482		/* Unable to use linear approximation */
483		temp = data->comp[low].temp_c * 1000;
484	} else {
485		temp = data->comp[low].temp_c * 1000 +
486			((data->comp[high].temp_c - data->comp[low].temp_c) *
487			 1000 * ((int)ohm - (int)data->comp[low].ohm)) /
488			((int)data->comp[high].ohm - (int)data->comp[low].ohm);
489	}
490	return temp;
491}
492
493static int ntc_thermistor_get_ohm(struct ntc_data *data)
494{
495	int read_uv;
496
497	if (data->pdata->read_ohm)
498		return data->pdata->read_ohm();
499
500	if (data->pdata->read_uv) {
501		read_uv = data->pdata->read_uv(data->pdata);
502		if (read_uv < 0)
503			return read_uv;
504		return get_ohm_of_thermistor(data, read_uv);
505	}
506	return -EINVAL;
507}
508
509static int ntc_read_temp(void *data, int *temp)
510{
511	int ohm;
512
513	ohm = ntc_thermistor_get_ohm(data);
514	if (ohm < 0)
515		return ohm;
516
517	*temp = get_temp_mc(data, ohm);
518
519	return 0;
520}
521
522static ssize_t ntc_show_type(struct device *dev,
523		struct device_attribute *attr, char *buf)
524{
525	return sprintf(buf, "4\n");
526}
527
528static ssize_t ntc_show_temp(struct device *dev,
529		struct device_attribute *attr, char *buf)
530{
531	struct ntc_data *data = dev_get_drvdata(dev);
532	int ohm;
533
534	ohm = ntc_thermistor_get_ohm(data);
535	if (ohm < 0)
536		return ohm;
537
538	return sprintf(buf, "%d\n", get_temp_mc(data, ohm));
539}
540
541static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0);
542static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0);
543
544static struct attribute *ntc_attrs[] = {
545	&sensor_dev_attr_temp1_type.dev_attr.attr,
546	&sensor_dev_attr_temp1_input.dev_attr.attr,
547	NULL,
548};
549ATTRIBUTE_GROUPS(ntc);
550
551static const struct thermal_zone_of_device_ops ntc_of_thermal_ops = {
552	.get_temp = ntc_read_temp,
553};
554
555static int ntc_thermistor_probe(struct platform_device *pdev)
556{
557	struct thermal_zone_device *tz;
558	struct device *dev = &pdev->dev;
559	const struct of_device_id *of_id =
560			of_match_device(of_match_ptr(ntc_match), dev);
561	const struct platform_device_id *pdev_id;
562	struct ntc_thermistor_platform_data *pdata;
563	struct device *hwmon_dev;
564	struct ntc_data *data;
565
566	pdata = ntc_thermistor_parse_dt(dev);
567	if (IS_ERR(pdata))
568		return PTR_ERR(pdata);
569	else if (pdata == NULL)
570		pdata = dev_get_platdata(dev);
571
572	if (!pdata) {
573		dev_err(dev, "No platform init data supplied.\n");
574		return -ENODEV;
575	}
576
577	/* Either one of the two is required. */
578	if (!pdata->read_uv && !pdata->read_ohm) {
579		dev_err(dev,
580			"Both read_uv and read_ohm missing. Need either one of the two.\n");
581		return -EINVAL;
582	}
583
584	if (pdata->read_uv && pdata->read_ohm) {
585		dev_warn(dev,
586			 "Only one of read_uv and read_ohm is needed; ignoring read_uv.\n");
587		pdata->read_uv = NULL;
588	}
589
590	if (pdata->read_uv && (pdata->pullup_uv == 0 ||
591				(pdata->pullup_ohm == 0 && pdata->connect ==
592				 NTC_CONNECTED_GROUND) ||
593				(pdata->pulldown_ohm == 0 && pdata->connect ==
594				 NTC_CONNECTED_POSITIVE) ||
595				(pdata->connect != NTC_CONNECTED_POSITIVE &&
596				 pdata->connect != NTC_CONNECTED_GROUND))) {
597		dev_err(dev, "Required data to use read_uv not supplied.\n");
598		return -EINVAL;
599	}
600
601	data = devm_kzalloc(dev, sizeof(struct ntc_data), GFP_KERNEL);
602	if (!data)
603		return -ENOMEM;
604
605	pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
606
607	data->pdata = pdata;
608
609	switch (pdev_id->driver_data) {
610	case TYPE_NCPXXWB473:
611		data->comp = ncpXXwb473;
612		data->n_comp = ARRAY_SIZE(ncpXXwb473);
613		break;
614	case TYPE_NCPXXWL333:
615		data->comp = ncpXXwl333;
616		data->n_comp = ARRAY_SIZE(ncpXXwl333);
617		break;
618	case TYPE_B57330V2103:
619		data->comp = b57330v2103;
620		data->n_comp = ARRAY_SIZE(b57330v2103);
621		break;
622	case TYPE_NCPXXWF104:
623		data->comp = ncpXXwf104;
624		data->n_comp = ARRAY_SIZE(ncpXXwf104);
625		break;
626	case TYPE_NCPXXXH103:
627		data->comp = ncpXXxh103;
628		data->n_comp = ARRAY_SIZE(ncpXXxh103);
629		break;
630	default:
631		dev_err(dev, "Unknown device type: %lu(%s)\n",
632				pdev_id->driver_data, pdev_id->name);
633		return -EINVAL;
634	}
635
636	hwmon_dev = devm_hwmon_device_register_with_groups(dev, pdev_id->name,
637							   data, ntc_groups);
638	if (IS_ERR(hwmon_dev)) {
639		dev_err(dev, "unable to register as hwmon device.\n");
640		return PTR_ERR(hwmon_dev);
641	}
642
643	dev_info(dev, "Thermistor type: %s successfully probed.\n",
644		 pdev_id->name);
645
646	tz = devm_thermal_zone_of_sensor_register(dev, 0, data,
647						  &ntc_of_thermal_ops);
648	if (IS_ERR(tz))
649		dev_dbg(dev, "Failed to register to thermal fw.\n");
650
651	return 0;
652}
653
654static struct platform_driver ntc_thermistor_driver = {
655	.driver = {
656		.name = "ntc-thermistor",
657		.of_match_table = of_match_ptr(ntc_match),
658	},
659	.probe = ntc_thermistor_probe,
660	.id_table = ntc_thermistor_id,
661};
662
663module_platform_driver(ntc_thermistor_driver);
664
665MODULE_DESCRIPTION("NTC Thermistor Driver");
666MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
667MODULE_LICENSE("GPL");
668MODULE_ALIAS("platform:ntc-thermistor");