hwmon: (ntc_thermistor) Fix dependencies
[linux-2.6-block.git] / drivers / hwmon / ntc_thermistor.c
CommitLineData
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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>
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29#include <linux/of.h>
30#include <linux/of_device.h>
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31
32#include <linux/platform_data/ntc_thermistor.h>
33
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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
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39#include <linux/hwmon.h>
40#include <linux/hwmon-sysfs.h>
41
42struct ntc_compensation {
088ce2ac 43 int temp_c;
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44 unsigned int ohm;
45};
46
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47static const struct platform_device_id ntc_thermistor_id[] = {
48 { "ncp15wb473", TYPE_NCPXXWB473 },
49 { "ncp18wb473", TYPE_NCPXXWB473 },
50 { "ncp21wb473", TYPE_NCPXXWB473 },
51 { "ncp03wb473", TYPE_NCPXXWB473 },
52 { "ncp15wl333", TYPE_NCPXXWL333 },
53 { },
54};
55
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56/*
57 * A compensation table should be sorted by the values of .ohm
58 * in descending order.
59 * The following compensation tables are from the specification of Murata NTC
60 * Thermistors Datasheet
61 */
4626dcff 62static const struct ntc_compensation ncpXXwb473[] = {
088ce2ac
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63 { .temp_c = -40, .ohm = 1747920 },
64 { .temp_c = -35, .ohm = 1245428 },
65 { .temp_c = -30, .ohm = 898485 },
66 { .temp_c = -25, .ohm = 655802 },
67 { .temp_c = -20, .ohm = 483954 },
68 { .temp_c = -15, .ohm = 360850 },
69 { .temp_c = -10, .ohm = 271697 },
70 { .temp_c = -5, .ohm = 206463 },
71 { .temp_c = 0, .ohm = 158214 },
72 { .temp_c = 5, .ohm = 122259 },
73 { .temp_c = 10, .ohm = 95227 },
74 { .temp_c = 15, .ohm = 74730 },
75 { .temp_c = 20, .ohm = 59065 },
76 { .temp_c = 25, .ohm = 47000 },
77 { .temp_c = 30, .ohm = 37643 },
78 { .temp_c = 35, .ohm = 30334 },
79 { .temp_c = 40, .ohm = 24591 },
80 { .temp_c = 45, .ohm = 20048 },
81 { .temp_c = 50, .ohm = 16433 },
82 { .temp_c = 55, .ohm = 13539 },
83 { .temp_c = 60, .ohm = 11209 },
84 { .temp_c = 65, .ohm = 9328 },
85 { .temp_c = 70, .ohm = 7798 },
86 { .temp_c = 75, .ohm = 6544 },
87 { .temp_c = 80, .ohm = 5518 },
88 { .temp_c = 85, .ohm = 4674 },
89 { .temp_c = 90, .ohm = 3972 },
90 { .temp_c = 95, .ohm = 3388 },
91 { .temp_c = 100, .ohm = 2902 },
92 { .temp_c = 105, .ohm = 2494 },
93 { .temp_c = 110, .ohm = 2150 },
94 { .temp_c = 115, .ohm = 1860 },
95 { .temp_c = 120, .ohm = 1615 },
96 { .temp_c = 125, .ohm = 1406 },
f22aaaa7 97};
4626dcff 98static const struct ntc_compensation ncpXXwl333[] = {
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99 { .temp_c = -40, .ohm = 1610154 },
100 { .temp_c = -35, .ohm = 1130850 },
101 { .temp_c = -30, .ohm = 802609 },
102 { .temp_c = -25, .ohm = 575385 },
103 { .temp_c = -20, .ohm = 416464 },
104 { .temp_c = -15, .ohm = 304219 },
105 { .temp_c = -10, .ohm = 224193 },
106 { .temp_c = -5, .ohm = 166623 },
107 { .temp_c = 0, .ohm = 124850 },
108 { .temp_c = 5, .ohm = 94287 },
109 { .temp_c = 10, .ohm = 71747 },
110 { .temp_c = 15, .ohm = 54996 },
111 { .temp_c = 20, .ohm = 42455 },
112 { .temp_c = 25, .ohm = 33000 },
113 { .temp_c = 30, .ohm = 25822 },
114 { .temp_c = 35, .ohm = 20335 },
115 { .temp_c = 40, .ohm = 16115 },
116 { .temp_c = 45, .ohm = 12849 },
117 { .temp_c = 50, .ohm = 10306 },
118 { .temp_c = 55, .ohm = 8314 },
119 { .temp_c = 60, .ohm = 6746 },
120 { .temp_c = 65, .ohm = 5503 },
121 { .temp_c = 70, .ohm = 4513 },
122 { .temp_c = 75, .ohm = 3721 },
123 { .temp_c = 80, .ohm = 3084 },
124 { .temp_c = 85, .ohm = 2569 },
125 { .temp_c = 90, .ohm = 2151 },
126 { .temp_c = 95, .ohm = 1809 },
127 { .temp_c = 100, .ohm = 1529 },
128 { .temp_c = 105, .ohm = 1299 },
129 { .temp_c = 110, .ohm = 1108 },
130 { .temp_c = 115, .ohm = 949 },
131 { .temp_c = 120, .ohm = 817 },
132 { .temp_c = 125, .ohm = 707 },
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133};
134
135struct ntc_data {
136 struct device *hwmon_dev;
137 struct ntc_thermistor_platform_data *pdata;
138 const struct ntc_compensation *comp;
139 struct device *dev;
140 int n_comp;
141 char name[PLATFORM_NAME_SIZE];
142};
143
59cf4243 144#if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
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145static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
146{
147 struct iio_channel *channel = pdata->chan;
d3d89c46 148 s64 result;
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149 int val, ret;
150
151 ret = iio_read_channel_raw(channel, &val);
152 if (ret < 0) {
153 pr_err("read channel() error: %d\n", ret);
154 return ret;
155 }
156
157 /* unit: mV */
d3d89c46 158 result = pdata->pullup_uv * (s64) val;
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159 result >>= 12;
160
d3d89c46 161 return (int)result;
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162}
163
164static const struct of_device_id ntc_match[] = {
165 { .compatible = "ntc,ncp15wb473",
166 .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
167 { .compatible = "ntc,ncp18wb473",
168 .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
169 { .compatible = "ntc,ncp21wb473",
170 .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
171 { .compatible = "ntc,ncp03wb473",
172 .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
173 { .compatible = "ntc,ncp15wl333",
174 .data = &ntc_thermistor_id[TYPE_NCPXXWL333] },
175 { },
176};
177MODULE_DEVICE_TABLE(of, ntc_match);
178
179static struct ntc_thermistor_platform_data *
180ntc_thermistor_parse_dt(struct platform_device *pdev)
181{
182 struct iio_channel *chan;
183 struct device_node *np = pdev->dev.of_node;
184 struct ntc_thermistor_platform_data *pdata;
185
186 if (!np)
187 return NULL;
188
189 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
190 if (!pdata)
191 return ERR_PTR(-ENOMEM);
192
193 chan = iio_channel_get(&pdev->dev, NULL);
194 if (IS_ERR(chan))
195 return ERR_CAST(chan);
196
088ce2ac 197 if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
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198 return ERR_PTR(-ENODEV);
199 if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
200 return ERR_PTR(-ENODEV);
201 if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
202 return ERR_PTR(-ENODEV);
203
204 if (of_find_property(np, "connected-positive", NULL))
205 pdata->connect = NTC_CONNECTED_POSITIVE;
206 else /* status change should be possible if not always on. */
207 pdata->connect = NTC_CONNECTED_GROUND;
208
209 pdata->chan = chan;
088ce2ac 210 pdata->read_uv = ntc_adc_iio_read;
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211
212 return pdata;
213}
214static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
215{
216 if (pdata->chan)
217 iio_channel_release(pdata->chan);
218}
219#else
220static struct ntc_thermistor_platform_data *
221ntc_thermistor_parse_dt(struct platform_device *pdev)
222{
223 return NULL;
224}
225
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226#define ntc_match NULL
227
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228static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
229{ }
230#endif
231
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232static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
233{
234 if (divisor == 0 && dividend == 0)
235 return 0;
236 if (divisor == 0)
237 return UINT_MAX;
238 return div64_u64(dividend, divisor);
239}
240
088ce2ac 241static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv)
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242{
243 struct ntc_thermistor_platform_data *pdata = data->pdata;
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244 u64 mv = uv / 1000;
245 u64 pmv = pdata->pullup_uv / 1000;
246 u64 n, puo, pdo;
247 puo = pdata->pullup_ohm;
248 pdo = pdata->pulldown_ohm;
f22aaaa7 249
088ce2ac 250 if (mv == 0) {
f22aaaa7 251 if (pdata->connect == NTC_CONNECTED_POSITIVE)
dbe43a62 252 return INT_MAX;
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253 return 0;
254 }
088ce2ac 255 if (mv >= pmv)
f22aaaa7 256 return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
dbe43a62 257 0 : INT_MAX;
f22aaaa7 258
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259 if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
260 n = div64_u64_safe(pdo * (pmv - mv), mv);
261 else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
262 n = div64_u64_safe(puo * mv, pmv - mv);
f22aaaa7 263 else if (pdata->connect == NTC_CONNECTED_POSITIVE)
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264 n = div64_u64_safe(pdo * puo * (pmv - mv),
265 puo * mv - pdo * (pmv - mv));
f22aaaa7 266 else
088ce2ac 267 n = div64_u64_safe(pdo * puo * mv, pdo * (pmv - mv) - puo * mv);
f22aaaa7 268
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269 if (n > INT_MAX)
270 n = INT_MAX;
271 return n;
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272}
273
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274static void lookup_comp(struct ntc_data *data, unsigned int ohm,
275 int *i_low, int *i_high)
f22aaaa7 276{
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277 int start, end, mid;
278
279 /*
280 * Handle special cases: Resistance is higher than or equal to
281 * resistance in first table entry, or resistance is lower or equal
282 * to resistance in last table entry.
283 * In these cases, return i_low == i_high, either pointing to the
284 * beginning or to the end of the table depending on the condition.
285 */
286 if (ohm >= data->comp[0].ohm) {
287 *i_low = 0;
288 *i_high = 0;
289 return;
290 }
291 if (ohm <= data->comp[data->n_comp - 1].ohm) {
292 *i_low = data->n_comp - 1;
293 *i_high = data->n_comp - 1;
294 return;
295 }
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296
297 /* Do a binary search on compensation table */
298 start = 0;
299 end = data->n_comp;
dbe43a62 300 while (start < end) {
f22aaaa7 301 mid = start + (end - start) / 2;
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302 /*
303 * start <= mid < end
304 * data->comp[start].ohm > ohm >= data->comp[end].ohm
305 *
306 * We could check for "ohm == data->comp[mid].ohm" here, but
307 * that is a quite unlikely condition, and we would have to
308 * check again after updating start. Check it at the end instead
309 * for simplicity.
310 */
311 if (ohm >= data->comp[mid].ohm) {
f22aaaa7 312 end = mid;
f22aaaa7 313 } else {
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314 start = mid + 1;
315 /*
316 * ohm >= data->comp[start].ohm might be true here,
317 * since we set start to mid + 1. In that case, we are
318 * done. We could keep going, but the condition is quite
319 * likely to occur, so it is worth checking for it.
320 */
321 if (ohm >= data->comp[start].ohm)
322 end = start;
f22aaaa7 323 }
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324 /*
325 * start <= end
326 * data->comp[start].ohm >= ohm >= data->comp[end].ohm
327 */
f22aaaa7 328 }
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329 /*
330 * start == end
331 * ohm >= data->comp[end].ohm
332 */
333 *i_low = end;
334 if (ohm == data->comp[end].ohm)
335 *i_high = end;
336 else
337 *i_high = end - 1;
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338}
339
088ce2ac 340static int get_temp_mc(struct ntc_data *data, unsigned int ohm)
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341{
342 int low, high;
dbe43a62 343 int temp;
f22aaaa7 344
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345 lookup_comp(data, ohm, &low, &high);
346 if (low == high) {
f22aaaa7 347 /* Unable to use linear approximation */
088ce2ac 348 temp = data->comp[low].temp_c * 1000;
f22aaaa7 349 } else {
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350 temp = data->comp[low].temp_c * 1000 +
351 ((data->comp[high].temp_c - data->comp[low].temp_c) *
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352 1000 * ((int)ohm - (int)data->comp[low].ohm)) /
353 ((int)data->comp[high].ohm - (int)data->comp[low].ohm);
354 }
dbe43a62 355 return temp;
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356}
357
dbe43a62 358static int ntc_thermistor_get_ohm(struct ntc_data *data)
f22aaaa7 359{
088ce2ac 360 int read_uv;
f22aaaa7 361
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362 if (data->pdata->read_ohm)
363 return data->pdata->read_ohm();
f22aaaa7 364
088ce2ac
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365 if (data->pdata->read_uv) {
366 read_uv = data->pdata->read_uv(data->pdata);
367 if (read_uv < 0)
368 return read_uv;
369 return get_ohm_of_thermistor(data, read_uv);
f22aaaa7 370 }
dbe43a62 371 return -EINVAL;
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372}
373
374static ssize_t ntc_show_name(struct device *dev,
375 struct device_attribute *attr, char *buf)
376{
377 struct ntc_data *data = dev_get_drvdata(dev);
378
379 return sprintf(buf, "%s\n", data->name);
380}
381
382static ssize_t ntc_show_type(struct device *dev,
383 struct device_attribute *attr, char *buf)
384{
385 return sprintf(buf, "4\n");
386}
387
388static ssize_t ntc_show_temp(struct device *dev,
389 struct device_attribute *attr, char *buf)
390{
391 struct ntc_data *data = dev_get_drvdata(dev);
dbe43a62
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392 int ohm;
393
394 ohm = ntc_thermistor_get_ohm(data);
395 if (ohm < 0)
396 return ohm;
f22aaaa7 397
088ce2ac 398 return sprintf(buf, "%d\n", get_temp_mc(data, ohm));
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399}
400
401static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0);
402static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0);
403static DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL);
404
405static struct attribute *ntc_attributes[] = {
406 &dev_attr_name.attr,
407 &sensor_dev_attr_temp1_type.dev_attr.attr,
408 &sensor_dev_attr_temp1_input.dev_attr.attr,
409 NULL,
410};
411
412static const struct attribute_group ntc_attr_group = {
413 .attrs = ntc_attributes,
414};
415
6c931ae1 416static int ntc_thermistor_probe(struct platform_device *pdev)
f22aaaa7 417{
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418 const struct of_device_id *of_id =
419 of_match_device(of_match_ptr(ntc_match), &pdev->dev);
420 const struct platform_device_id *pdev_id;
421 struct ntc_thermistor_platform_data *pdata;
f22aaaa7 422 struct ntc_data *data;
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423 int ret;
424
425 pdata = ntc_thermistor_parse_dt(pdev);
426 if (IS_ERR(pdata))
427 return PTR_ERR(pdata);
428 else if (pdata == NULL)
a8b3a3a5 429 pdata = dev_get_platdata(&pdev->dev);
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430
431 if (!pdata) {
432 dev_err(&pdev->dev, "No platform init data supplied.\n");
433 return -ENODEV;
434 }
435
436 /* Either one of the two is required. */
088ce2ac 437 if (!pdata->read_uv && !pdata->read_ohm) {
a7871def 438 dev_err(&pdev->dev,
088ce2ac 439 "Both read_uv and read_ohm missing. Need either one of the two.\n");
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440 return -EINVAL;
441 }
442
088ce2ac 443 if (pdata->read_uv && pdata->read_ohm) {
a7871def 444 dev_warn(&pdev->dev,
088ce2ac
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445 "Only one of read_uv and read_ohm is needed; ignoring read_uv.\n");
446 pdata->read_uv = NULL;
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447 }
448
088ce2ac 449 if (pdata->read_uv && (pdata->pullup_uv == 0 ||
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450 (pdata->pullup_ohm == 0 && pdata->connect ==
451 NTC_CONNECTED_GROUND) ||
452 (pdata->pulldown_ohm == 0 && pdata->connect ==
453 NTC_CONNECTED_POSITIVE) ||
454 (pdata->connect != NTC_CONNECTED_POSITIVE &&
455 pdata->connect != NTC_CONNECTED_GROUND))) {
a7871def 456 dev_err(&pdev->dev,
088ce2ac 457 "Required data to use read_uv not supplied.\n");
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458 return -EINVAL;
459 }
460
41141e64 461 data = devm_kzalloc(&pdev->dev, sizeof(struct ntc_data), GFP_KERNEL);
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462 if (!data)
463 return -ENOMEM;
464
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465 pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
466
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467 data->dev = &pdev->dev;
468 data->pdata = pdata;
9e8269de 469 strlcpy(data->name, pdev_id->name, sizeof(data->name));
f22aaaa7 470
9e8269de 471 switch (pdev_id->driver_data) {
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472 case TYPE_NCPXXWB473:
473 data->comp = ncpXXwb473;
474 data->n_comp = ARRAY_SIZE(ncpXXwb473);
475 break;
476 case TYPE_NCPXXWL333:
477 data->comp = ncpXXwl333;
478 data->n_comp = ARRAY_SIZE(ncpXXwl333);
479 break;
480 default:
481 dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
9e8269de 482 pdev_id->driver_data, pdev_id->name);
41141e64 483 return -EINVAL;
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484 }
485
486 platform_set_drvdata(pdev, data);
487
488 ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group);
489 if (ret) {
490 dev_err(data->dev, "unable to create sysfs files\n");
41141e64 491 return ret;
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492 }
493
494 data->hwmon_dev = hwmon_device_register(data->dev);
425d2476 495 if (IS_ERR(data->hwmon_dev)) {
f22aaaa7 496 dev_err(data->dev, "unable to register as hwmon device.\n");
425d2476 497 ret = PTR_ERR(data->hwmon_dev);
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498 goto err_after_sysfs;
499 }
500
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501 dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
502 pdev->name);
503
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504 return 0;
505err_after_sysfs:
506 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
9e8269de 507 ntc_iio_channel_release(pdata);
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508 return ret;
509}
510
281dfd0b 511static int ntc_thermistor_remove(struct platform_device *pdev)
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512{
513 struct ntc_data *data = platform_get_drvdata(pdev);
9e8269de 514 struct ntc_thermistor_platform_data *pdata = data->pdata;
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515
516 hwmon_device_unregister(data->hwmon_dev);
517 sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
9e8269de 518 ntc_iio_channel_release(pdata);
f22aaaa7 519
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520 return 0;
521}
522
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523static struct platform_driver ntc_thermistor_driver = {
524 .driver = {
525 .name = "ntc-thermistor",
526 .owner = THIS_MODULE,
9e8269de 527 .of_match_table = of_match_ptr(ntc_match),
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528 },
529 .probe = ntc_thermistor_probe,
9e5e9b7a 530 .remove = ntc_thermistor_remove,
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531 .id_table = ntc_thermistor_id,
532};
533
25a236a5 534module_platform_driver(ntc_thermistor_driver);
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535
536MODULE_DESCRIPTION("NTC Thermistor Driver");
537MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
538MODULE_LICENSE("GPL");
539MODULE_ALIAS("platform:ntc-thermistor");