Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
f22aaaa7 DK |
2 | /* |
3 | * ntc_thermistor.c - NTC Thermistors | |
4 | * | |
5 | * Copyright (C) 2010 Samsung Electronics | |
6 | * MyungJoo Ham <myungjoo.ham@samsung.com> | |
f22aaaa7 DK |
7 | */ |
8 | ||
9 | #include <linux/slab.h> | |
10 | #include <linux/module.h> | |
f22aaaa7 | 11 | #include <linux/math64.h> |
70760e80 | 12 | #include <linux/mod_devicetable.h> |
f22aaaa7 | 13 | #include <linux/platform_device.h> |
70760e80 | 14 | #include <linux/property.h> |
f22aaaa7 | 15 | #include <linux/err.h> |
bd56c1e9 | 16 | #include <linux/fixp-arith.h> |
11a24ca7 LW |
17 | #include <linux/iio/consumer.h> |
18 | #include <linux/hwmon.h> | |
f22aaaa7 | 19 | |
11a24ca7 LW |
20 | enum ntc_thermistor_type { |
21 | TYPE_B57330V2103, | |
22 | TYPE_B57891S0103, | |
23 | TYPE_NCPXXWB473, | |
24 | TYPE_NCPXXWF104, | |
25 | TYPE_NCPXXWL333, | |
26 | TYPE_NCPXXXH103, | |
27 | }; | |
f22aaaa7 | 28 | |
f22aaaa7 | 29 | struct ntc_compensation { |
088ce2ac | 30 | int temp_c; |
f22aaaa7 DK |
31 | unsigned int ohm; |
32 | }; | |
33 | ||
e056fe25 PR |
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, | |
e13e979b | 48 | NTC_SSG1404001221, |
e056fe25 PR |
49 | NTC_LAST, |
50 | }; | |
51 | ||
9e8269de | 52 | static const struct platform_device_id ntc_thermistor_id[] = { |
e056fe25 PR |
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 }, | |
e23e40fd | 62 | [NTC_SSG1404001221] = { "ssg1404_001221", TYPE_NCPXXWB473 }, |
e056fe25 | 63 | [NTC_LAST] = { }, |
9e8269de NKC |
64 | }; |
65 | ||
f22aaaa7 DK |
66 | /* |
67 | * A compensation table should be sorted by the values of .ohm | |
68 | * in descending order. | |
69 | * The following compensation tables are from the specification of Murata NTC | |
70 | * Thermistors Datasheet | |
71 | */ | |
4626dcff | 72 | static const struct ntc_compensation ncpXXwb473[] = { |
088ce2ac GR |
73 | { .temp_c = -40, .ohm = 1747920 }, |
74 | { .temp_c = -35, .ohm = 1245428 }, | |
75 | { .temp_c = -30, .ohm = 898485 }, | |
76 | { .temp_c = -25, .ohm = 655802 }, | |
77 | { .temp_c = -20, .ohm = 483954 }, | |
78 | { .temp_c = -15, .ohm = 360850 }, | |
79 | { .temp_c = -10, .ohm = 271697 }, | |
80 | { .temp_c = -5, .ohm = 206463 }, | |
81 | { .temp_c = 0, .ohm = 158214 }, | |
82 | { .temp_c = 5, .ohm = 122259 }, | |
83 | { .temp_c = 10, .ohm = 95227 }, | |
84 | { .temp_c = 15, .ohm = 74730 }, | |
85 | { .temp_c = 20, .ohm = 59065 }, | |
86 | { .temp_c = 25, .ohm = 47000 }, | |
87 | { .temp_c = 30, .ohm = 37643 }, | |
88 | { .temp_c = 35, .ohm = 30334 }, | |
89 | { .temp_c = 40, .ohm = 24591 }, | |
90 | { .temp_c = 45, .ohm = 20048 }, | |
91 | { .temp_c = 50, .ohm = 16433 }, | |
92 | { .temp_c = 55, .ohm = 13539 }, | |
93 | { .temp_c = 60, .ohm = 11209 }, | |
94 | { .temp_c = 65, .ohm = 9328 }, | |
95 | { .temp_c = 70, .ohm = 7798 }, | |
96 | { .temp_c = 75, .ohm = 6544 }, | |
97 | { .temp_c = 80, .ohm = 5518 }, | |
98 | { .temp_c = 85, .ohm = 4674 }, | |
99 | { .temp_c = 90, .ohm = 3972 }, | |
100 | { .temp_c = 95, .ohm = 3388 }, | |
101 | { .temp_c = 100, .ohm = 2902 }, | |
102 | { .temp_c = 105, .ohm = 2494 }, | |
103 | { .temp_c = 110, .ohm = 2150 }, | |
104 | { .temp_c = 115, .ohm = 1860 }, | |
105 | { .temp_c = 120, .ohm = 1615 }, | |
106 | { .temp_c = 125, .ohm = 1406 }, | |
f22aaaa7 | 107 | }; |
4626dcff | 108 | static const struct ntc_compensation ncpXXwl333[] = { |
088ce2ac GR |
109 | { .temp_c = -40, .ohm = 1610154 }, |
110 | { .temp_c = -35, .ohm = 1130850 }, | |
111 | { .temp_c = -30, .ohm = 802609 }, | |
112 | { .temp_c = -25, .ohm = 575385 }, | |
113 | { .temp_c = -20, .ohm = 416464 }, | |
114 | { .temp_c = -15, .ohm = 304219 }, | |
115 | { .temp_c = -10, .ohm = 224193 }, | |
116 | { .temp_c = -5, .ohm = 166623 }, | |
117 | { .temp_c = 0, .ohm = 124850 }, | |
118 | { .temp_c = 5, .ohm = 94287 }, | |
119 | { .temp_c = 10, .ohm = 71747 }, | |
120 | { .temp_c = 15, .ohm = 54996 }, | |
121 | { .temp_c = 20, .ohm = 42455 }, | |
122 | { .temp_c = 25, .ohm = 33000 }, | |
123 | { .temp_c = 30, .ohm = 25822 }, | |
124 | { .temp_c = 35, .ohm = 20335 }, | |
125 | { .temp_c = 40, .ohm = 16115 }, | |
126 | { .temp_c = 45, .ohm = 12849 }, | |
127 | { .temp_c = 50, .ohm = 10306 }, | |
128 | { .temp_c = 55, .ohm = 8314 }, | |
129 | { .temp_c = 60, .ohm = 6746 }, | |
130 | { .temp_c = 65, .ohm = 5503 }, | |
131 | { .temp_c = 70, .ohm = 4513 }, | |
132 | { .temp_c = 75, .ohm = 3721 }, | |
133 | { .temp_c = 80, .ohm = 3084 }, | |
134 | { .temp_c = 85, .ohm = 2569 }, | |
135 | { .temp_c = 90, .ohm = 2151 }, | |
136 | { .temp_c = 95, .ohm = 1809 }, | |
137 | { .temp_c = 100, .ohm = 1529 }, | |
138 | { .temp_c = 105, .ohm = 1299 }, | |
139 | { .temp_c = 110, .ohm = 1108 }, | |
140 | { .temp_c = 115, .ohm = 949 }, | |
141 | { .temp_c = 120, .ohm = 817 }, | |
142 | { .temp_c = 125, .ohm = 707 }, | |
f22aaaa7 DK |
143 | }; |
144 | ||
887ee434 BS |
145 | static const struct ntc_compensation ncpXXwf104[] = { |
146 | { .temp_c = -40, .ohm = 4397119 }, | |
147 | { .temp_c = -35, .ohm = 3088599 }, | |
148 | { .temp_c = -30, .ohm = 2197225 }, | |
149 | { .temp_c = -25, .ohm = 1581881 }, | |
150 | { .temp_c = -20, .ohm = 1151037 }, | |
151 | { .temp_c = -15, .ohm = 846579 }, | |
152 | { .temp_c = -10, .ohm = 628988 }, | |
153 | { .temp_c = -5, .ohm = 471632 }, | |
154 | { .temp_c = 0, .ohm = 357012 }, | |
155 | { .temp_c = 5, .ohm = 272500 }, | |
156 | { .temp_c = 10, .ohm = 209710 }, | |
157 | { .temp_c = 15, .ohm = 162651 }, | |
158 | { .temp_c = 20, .ohm = 127080 }, | |
159 | { .temp_c = 25, .ohm = 100000 }, | |
160 | { .temp_c = 30, .ohm = 79222 }, | |
161 | { .temp_c = 35, .ohm = 63167 }, | |
162 | { .temp_c = 40, .ohm = 50677 }, | |
163 | { .temp_c = 45, .ohm = 40904 }, | |
164 | { .temp_c = 50, .ohm = 33195 }, | |
165 | { .temp_c = 55, .ohm = 27091 }, | |
166 | { .temp_c = 60, .ohm = 22224 }, | |
167 | { .temp_c = 65, .ohm = 18323 }, | |
168 | { .temp_c = 70, .ohm = 15184 }, | |
169 | { .temp_c = 75, .ohm = 12635 }, | |
170 | { .temp_c = 80, .ohm = 10566 }, | |
171 | { .temp_c = 85, .ohm = 8873 }, | |
172 | { .temp_c = 90, .ohm = 7481 }, | |
173 | { .temp_c = 95, .ohm = 6337 }, | |
174 | { .temp_c = 100, .ohm = 5384 }, | |
175 | { .temp_c = 105, .ohm = 4594 }, | |
176 | { .temp_c = 110, .ohm = 3934 }, | |
177 | { .temp_c = 115, .ohm = 3380 }, | |
178 | { .temp_c = 120, .ohm = 2916 }, | |
179 | { .temp_c = 125, .ohm = 2522 }, | |
180 | }; | |
181 | ||
54ce3a0d JM |
182 | static const struct ntc_compensation ncpXXxh103[] = { |
183 | { .temp_c = -40, .ohm = 247565 }, | |
184 | { .temp_c = -35, .ohm = 181742 }, | |
185 | { .temp_c = -30, .ohm = 135128 }, | |
186 | { .temp_c = -25, .ohm = 101678 }, | |
187 | { .temp_c = -20, .ohm = 77373 }, | |
188 | { .temp_c = -15, .ohm = 59504 }, | |
189 | { .temp_c = -10, .ohm = 46222 }, | |
190 | { .temp_c = -5, .ohm = 36244 }, | |
191 | { .temp_c = 0, .ohm = 28674 }, | |
192 | { .temp_c = 5, .ohm = 22878 }, | |
193 | { .temp_c = 10, .ohm = 18399 }, | |
194 | { .temp_c = 15, .ohm = 14910 }, | |
195 | { .temp_c = 20, .ohm = 12169 }, | |
196 | { .temp_c = 25, .ohm = 10000 }, | |
197 | { .temp_c = 30, .ohm = 8271 }, | |
198 | { .temp_c = 35, .ohm = 6883 }, | |
199 | { .temp_c = 40, .ohm = 5762 }, | |
200 | { .temp_c = 45, .ohm = 4851 }, | |
201 | { .temp_c = 50, .ohm = 4105 }, | |
202 | { .temp_c = 55, .ohm = 3492 }, | |
203 | { .temp_c = 60, .ohm = 2985 }, | |
204 | { .temp_c = 65, .ohm = 2563 }, | |
205 | { .temp_c = 70, .ohm = 2211 }, | |
206 | { .temp_c = 75, .ohm = 1915 }, | |
207 | { .temp_c = 80, .ohm = 1666 }, | |
208 | { .temp_c = 85, .ohm = 1454 }, | |
209 | { .temp_c = 90, .ohm = 1275 }, | |
210 | { .temp_c = 95, .ohm = 1121 }, | |
211 | { .temp_c = 100, .ohm = 990 }, | |
212 | { .temp_c = 105, .ohm = 876 }, | |
213 | { .temp_c = 110, .ohm = 779 }, | |
214 | { .temp_c = 115, .ohm = 694 }, | |
215 | { .temp_c = 120, .ohm = 620 }, | |
216 | { .temp_c = 125, .ohm = 556 }, | |
217 | }; | |
218 | ||
ed67f087 | 219 | /* |
e8fda2c8 PR |
220 | * The following compensation tables are from the specifications in EPCOS NTC |
221 | * Thermistors Datasheets | |
ed67f087 JP |
222 | */ |
223 | static const struct ntc_compensation b57330v2103[] = { | |
224 | { .temp_c = -40, .ohm = 190030 }, | |
225 | { .temp_c = -35, .ohm = 145360 }, | |
226 | { .temp_c = -30, .ohm = 112060 }, | |
227 | { .temp_c = -25, .ohm = 87041 }, | |
228 | { .temp_c = -20, .ohm = 68104 }, | |
229 | { .temp_c = -15, .ohm = 53665 }, | |
230 | { .temp_c = -10, .ohm = 42576 }, | |
231 | { .temp_c = -5, .ohm = 34001 }, | |
232 | { .temp_c = 0, .ohm = 27326 }, | |
233 | { .temp_c = 5, .ohm = 22096 }, | |
234 | { .temp_c = 10, .ohm = 17973 }, | |
235 | { .temp_c = 15, .ohm = 14703 }, | |
236 | { .temp_c = 20, .ohm = 12090 }, | |
237 | { .temp_c = 25, .ohm = 10000 }, | |
238 | { .temp_c = 30, .ohm = 8311 }, | |
239 | { .temp_c = 35, .ohm = 6941 }, | |
240 | { .temp_c = 40, .ohm = 5825 }, | |
241 | { .temp_c = 45, .ohm = 4911 }, | |
242 | { .temp_c = 50, .ohm = 4158 }, | |
243 | { .temp_c = 55, .ohm = 3536 }, | |
244 | { .temp_c = 60, .ohm = 3019 }, | |
245 | { .temp_c = 65, .ohm = 2588 }, | |
246 | { .temp_c = 70, .ohm = 2227 }, | |
247 | { .temp_c = 75, .ohm = 1924 }, | |
248 | { .temp_c = 80, .ohm = 1668 }, | |
249 | { .temp_c = 85, .ohm = 1451 }, | |
250 | { .temp_c = 90, .ohm = 1266 }, | |
251 | { .temp_c = 95, .ohm = 1108 }, | |
252 | { .temp_c = 100, .ohm = 973 }, | |
253 | { .temp_c = 105, .ohm = 857 }, | |
254 | { .temp_c = 110, .ohm = 757 }, | |
255 | { .temp_c = 115, .ohm = 671 }, | |
256 | { .temp_c = 120, .ohm = 596 }, | |
257 | { .temp_c = 125, .ohm = 531 }, | |
258 | }; | |
259 | ||
e8fda2c8 PR |
260 | static const struct ntc_compensation b57891s0103[] = { |
261 | { .temp_c = -55.0, .ohm = 878900 }, | |
262 | { .temp_c = -50.0, .ohm = 617590 }, | |
263 | { .temp_c = -45.0, .ohm = 439340 }, | |
264 | { .temp_c = -40.0, .ohm = 316180 }, | |
265 | { .temp_c = -35.0, .ohm = 230060 }, | |
266 | { .temp_c = -30.0, .ohm = 169150 }, | |
267 | { .temp_c = -25.0, .ohm = 125550 }, | |
268 | { .temp_c = -20.0, .ohm = 94143 }, | |
269 | { .temp_c = -15.0, .ohm = 71172 }, | |
270 | { .temp_c = -10.0, .ohm = 54308 }, | |
271 | { .temp_c = -5.0, .ohm = 41505 }, | |
272 | { .temp_c = 0.0, .ohm = 32014 }, | |
273 | { .temp_c = 5.0, .ohm = 25011 }, | |
274 | { .temp_c = 10.0, .ohm = 19691 }, | |
275 | { .temp_c = 15.0, .ohm = 15618 }, | |
276 | { .temp_c = 20.0, .ohm = 12474 }, | |
277 | { .temp_c = 25.0, .ohm = 10000 }, | |
278 | { .temp_c = 30.0, .ohm = 8080 }, | |
279 | { .temp_c = 35.0, .ohm = 6569 }, | |
280 | { .temp_c = 40.0, .ohm = 5372 }, | |
281 | { .temp_c = 45.0, .ohm = 4424 }, | |
282 | { .temp_c = 50.0, .ohm = 3661 }, | |
283 | { .temp_c = 55.0, .ohm = 3039 }, | |
284 | { .temp_c = 60.0, .ohm = 2536 }, | |
285 | { .temp_c = 65.0, .ohm = 2128 }, | |
286 | { .temp_c = 70.0, .ohm = 1794 }, | |
287 | { .temp_c = 75.0, .ohm = 1518 }, | |
288 | { .temp_c = 80.0, .ohm = 1290 }, | |
289 | { .temp_c = 85.0, .ohm = 1100 }, | |
290 | { .temp_c = 90.0, .ohm = 942 }, | |
291 | { .temp_c = 95.0, .ohm = 809 }, | |
292 | { .temp_c = 100.0, .ohm = 697 }, | |
293 | { .temp_c = 105.0, .ohm = 604 }, | |
294 | { .temp_c = 110.0, .ohm = 525 }, | |
295 | { .temp_c = 115.0, .ohm = 457 }, | |
296 | { .temp_c = 120.0, .ohm = 400 }, | |
297 | { .temp_c = 125.0, .ohm = 351 }, | |
298 | { .temp_c = 130.0, .ohm = 308 }, | |
299 | { .temp_c = 135.0, .ohm = 272 }, | |
300 | { .temp_c = 140.0, .ohm = 240 }, | |
301 | { .temp_c = 145.0, .ohm = 213 }, | |
302 | { .temp_c = 150.0, .ohm = 189 }, | |
303 | { .temp_c = 155.0, .ohm = 168 }, | |
304 | }; | |
305 | ||
737c086e PR |
306 | struct ntc_type { |
307 | const struct ntc_compensation *comp; | |
308 | int n_comp; | |
309 | }; | |
310 | ||
311 | #define NTC_TYPE(ntc, compensation) \ | |
312 | [(ntc)] = { .comp = (compensation), .n_comp = ARRAY_SIZE(compensation) } | |
313 | ||
314 | static const struct ntc_type ntc_type[] = { | |
315 | NTC_TYPE(TYPE_B57330V2103, b57330v2103), | |
316 | NTC_TYPE(TYPE_B57891S0103, b57891s0103), | |
317 | NTC_TYPE(TYPE_NCPXXWB473, ncpXXwb473), | |
318 | NTC_TYPE(TYPE_NCPXXWF104, ncpXXwf104), | |
319 | NTC_TYPE(TYPE_NCPXXWL333, ncpXXwl333), | |
320 | NTC_TYPE(TYPE_NCPXXXH103, ncpXXxh103), | |
321 | }; | |
322 | ||
e380095b LW |
323 | /* |
324 | * pullup_uV, pullup_ohm, pulldown_ohm, and connect are required. | |
325 | * | |
326 | * How to setup pullup_ohm, pulldown_ohm, and connect is | |
327 | * described at Documentation/hwmon/ntc_thermistor.rst | |
328 | * | |
329 | * pullup/down_ohm: 0 for infinite / not-connected | |
330 | * | |
331 | * chan: iio_channel pointer to communicate with the ADC which the | |
332 | * thermistor is using for conversion of the analog values. | |
333 | */ | |
f22aaaa7 | 334 | struct ntc_data { |
f22aaaa7 | 335 | const struct ntc_compensation *comp; |
f22aaaa7 | 336 | int n_comp; |
e380095b LW |
337 | unsigned int pullup_uv; |
338 | unsigned int pullup_ohm; | |
339 | unsigned int pulldown_ohm; | |
340 | enum { NTC_CONNECTED_POSITIVE, NTC_CONNECTED_GROUND } connect; | |
341 | struct iio_channel *chan; | |
f22aaaa7 DK |
342 | }; |
343 | ||
e380095b | 344 | static int ntc_adc_iio_read(struct ntc_data *data) |
9e8269de | 345 | { |
e380095b | 346 | struct iio_channel *channel = data->chan; |
4f2d9cce | 347 | int uv, ret; |
9e8269de | 348 | |
4f2d9cce | 349 | ret = iio_read_channel_processed_scale(channel, &uv, 1000); |
9e8269de | 350 | if (ret < 0) { |
4f2d9cce | 351 | int raw; |
9e8269de | 352 | |
4f2d9cce LW |
353 | /* |
354 | * This fallback uses a raw read and then | |
355 | * assumes the ADC is 12 bits, scaling with | |
356 | * a factor 1000 to get to microvolts. | |
357 | */ | |
358 | ret = iio_read_channel_raw(channel, &raw); | |
359 | if (ret < 0) { | |
360 | pr_err("read channel() error: %d\n", ret); | |
361 | return ret; | |
362 | } | |
363 | ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000); | |
364 | if (ret < 0) { | |
365 | /* Assume 12 bit ADC with vref at pullup_uv */ | |
e380095b | 366 | uv = (data->pullup_uv * (s64)raw) >> 12; |
4f2d9cce | 367 | } |
0315253b | 368 | } |
9e8269de | 369 | |
0315253b | 370 | return uv; |
9e8269de NKC |
371 | } |
372 | ||
f22aaaa7 DK |
373 | static inline u64 div64_u64_safe(u64 dividend, u64 divisor) |
374 | { | |
375 | if (divisor == 0 && dividend == 0) | |
376 | return 0; | |
377 | if (divisor == 0) | |
378 | return UINT_MAX; | |
379 | return div64_u64(dividend, divisor); | |
380 | } | |
381 | ||
088ce2ac | 382 | static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv) |
f22aaaa7 | 383 | { |
e380095b | 384 | u32 puv = data->pullup_uv; |
088ce2ac | 385 | u64 n, puo, pdo; |
e380095b LW |
386 | puo = data->pullup_ohm; |
387 | pdo = data->pulldown_ohm; | |
f22aaaa7 | 388 | |
f6725ae2 | 389 | if (uv == 0) |
e380095b | 390 | return (data->connect == NTC_CONNECTED_POSITIVE) ? |
f6725ae2 CL |
391 | INT_MAX : 0; |
392 | if (uv >= puv) | |
e380095b | 393 | return (data->connect == NTC_CONNECTED_POSITIVE) ? |
dbe43a62 | 394 | 0 : INT_MAX; |
f22aaaa7 | 395 | |
e380095b | 396 | if (data->connect == NTC_CONNECTED_POSITIVE && puo == 0) |
f6725ae2 | 397 | n = div_u64(pdo * (puv - uv), uv); |
e380095b | 398 | else if (data->connect == NTC_CONNECTED_GROUND && pdo == 0) |
f6725ae2 | 399 | n = div_u64(puo * uv, puv - uv); |
e380095b | 400 | else if (data->connect == NTC_CONNECTED_POSITIVE) |
f6725ae2 CL |
401 | n = div64_u64_safe(pdo * puo * (puv - uv), |
402 | puo * uv - pdo * (puv - uv)); | |
f22aaaa7 | 403 | else |
f6725ae2 | 404 | n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv); |
f22aaaa7 | 405 | |
088ce2ac GR |
406 | if (n > INT_MAX) |
407 | n = INT_MAX; | |
408 | return n; | |
f22aaaa7 DK |
409 | } |
410 | ||
dbe43a62 GR |
411 | static void lookup_comp(struct ntc_data *data, unsigned int ohm, |
412 | int *i_low, int *i_high) | |
f22aaaa7 | 413 | { |
dbe43a62 GR |
414 | int start, end, mid; |
415 | ||
416 | /* | |
417 | * Handle special cases: Resistance is higher than or equal to | |
418 | * resistance in first table entry, or resistance is lower or equal | |
419 | * to resistance in last table entry. | |
420 | * In these cases, return i_low == i_high, either pointing to the | |
421 | * beginning or to the end of the table depending on the condition. | |
422 | */ | |
423 | if (ohm >= data->comp[0].ohm) { | |
424 | *i_low = 0; | |
425 | *i_high = 0; | |
426 | return; | |
427 | } | |
428 | if (ohm <= data->comp[data->n_comp - 1].ohm) { | |
429 | *i_low = data->n_comp - 1; | |
430 | *i_high = data->n_comp - 1; | |
431 | return; | |
432 | } | |
f22aaaa7 DK |
433 | |
434 | /* Do a binary search on compensation table */ | |
435 | start = 0; | |
436 | end = data->n_comp; | |
dbe43a62 | 437 | while (start < end) { |
f22aaaa7 | 438 | mid = start + (end - start) / 2; |
dbe43a62 GR |
439 | /* |
440 | * start <= mid < end | |
441 | * data->comp[start].ohm > ohm >= data->comp[end].ohm | |
442 | * | |
443 | * We could check for "ohm == data->comp[mid].ohm" here, but | |
444 | * that is a quite unlikely condition, and we would have to | |
445 | * check again after updating start. Check it at the end instead | |
446 | * for simplicity. | |
447 | */ | |
448 | if (ohm >= data->comp[mid].ohm) { | |
f22aaaa7 | 449 | end = mid; |
f22aaaa7 | 450 | } else { |
dbe43a62 GR |
451 | start = mid + 1; |
452 | /* | |
453 | * ohm >= data->comp[start].ohm might be true here, | |
454 | * since we set start to mid + 1. In that case, we are | |
455 | * done. We could keep going, but the condition is quite | |
456 | * likely to occur, so it is worth checking for it. | |
457 | */ | |
458 | if (ohm >= data->comp[start].ohm) | |
459 | end = start; | |
f22aaaa7 | 460 | } |
dbe43a62 GR |
461 | /* |
462 | * start <= end | |
463 | * data->comp[start].ohm >= ohm >= data->comp[end].ohm | |
464 | */ | |
f22aaaa7 | 465 | } |
dbe43a62 GR |
466 | /* |
467 | * start == end | |
468 | * ohm >= data->comp[end].ohm | |
469 | */ | |
470 | *i_low = end; | |
471 | if (ohm == data->comp[end].ohm) | |
472 | *i_high = end; | |
473 | else | |
474 | *i_high = end - 1; | |
f22aaaa7 DK |
475 | } |
476 | ||
088ce2ac | 477 | static int get_temp_mc(struct ntc_data *data, unsigned int ohm) |
f22aaaa7 DK |
478 | { |
479 | int low, high; | |
dbe43a62 | 480 | int temp; |
f22aaaa7 | 481 | |
dbe43a62 | 482 | lookup_comp(data, ohm, &low, &high); |
bd56c1e9 LW |
483 | /* |
484 | * First multiplying the table temperatures with 1000 to get to | |
485 | * millicentigrades (which is what we want) and then interpolating | |
486 | * will give the best precision. | |
487 | */ | |
488 | temp = fixp_linear_interpolate(data->comp[low].ohm, | |
489 | data->comp[low].temp_c * 1000, | |
490 | data->comp[high].ohm, | |
491 | data->comp[high].temp_c * 1000, | |
492 | ohm); | |
dbe43a62 | 493 | return temp; |
f22aaaa7 DK |
494 | } |
495 | ||
dbe43a62 | 496 | static int ntc_thermistor_get_ohm(struct ntc_data *data) |
f22aaaa7 | 497 | { |
088ce2ac | 498 | int read_uv; |
f22aaaa7 | 499 | |
e380095b | 500 | read_uv = ntc_adc_iio_read(data); |
209218ef LW |
501 | if (read_uv < 0) |
502 | return read_uv; | |
503 | return get_ohm_of_thermistor(data, read_uv); | |
f22aaaa7 DK |
504 | } |
505 | ||
7cc7de93 GR |
506 | static int ntc_read(struct device *dev, enum hwmon_sensor_types type, |
507 | u32 attr, int channel, long *val) | |
c08860ff | 508 | { |
7cc7de93 | 509 | struct ntc_data *data = dev_get_drvdata(dev); |
c08860ff JL |
510 | int ohm; |
511 | ||
7cc7de93 GR |
512 | switch (type) { |
513 | case hwmon_temp: | |
514 | switch (attr) { | |
515 | case hwmon_temp_input: | |
516 | ohm = ntc_thermistor_get_ohm(data); | |
517 | if (ohm < 0) | |
518 | return ohm; | |
519 | *val = get_temp_mc(data, ohm); | |
520 | return 0; | |
521 | case hwmon_temp_type: | |
522 | *val = 4; | |
523 | return 0; | |
524 | default: | |
525 | break; | |
526 | } | |
527 | break; | |
528 | default: | |
529 | break; | |
530 | } | |
531 | return -EINVAL; | |
c08860ff JL |
532 | } |
533 | ||
7cc7de93 GR |
534 | static umode_t ntc_is_visible(const void *data, enum hwmon_sensor_types type, |
535 | u32 attr, int channel) | |
f22aaaa7 | 536 | { |
7cc7de93 GR |
537 | if (type == hwmon_temp) { |
538 | switch (attr) { | |
539 | case hwmon_temp_input: | |
540 | case hwmon_temp_type: | |
541 | return 0444; | |
542 | default: | |
543 | break; | |
544 | } | |
545 | } | |
546 | return 0; | |
f22aaaa7 DK |
547 | } |
548 | ||
9add51f2 | 549 | static const struct hwmon_channel_info * const ntc_info[] = { |
0ddca577 GR |
550 | HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), |
551 | HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_TYPE), | |
7cc7de93 | 552 | NULL |
f22aaaa7 | 553 | }; |
f22aaaa7 | 554 | |
7cc7de93 GR |
555 | static const struct hwmon_ops ntc_hwmon_ops = { |
556 | .is_visible = ntc_is_visible, | |
557 | .read = ntc_read, | |
558 | }; | |
559 | ||
560 | static const struct hwmon_chip_info ntc_chip_info = { | |
561 | .ops = &ntc_hwmon_ops, | |
562 | .info = ntc_info, | |
2251aef6 EV |
563 | }; |
564 | ||
70760e80 LW |
565 | static int ntc_thermistor_parse_props(struct device *dev, |
566 | struct ntc_data *data) | |
e0149eeb LW |
567 | { |
568 | struct iio_channel *chan; | |
569 | enum iio_chan_type type; | |
e0149eeb LW |
570 | int ret; |
571 | ||
572 | chan = devm_iio_channel_get(dev, NULL); | |
573 | if (IS_ERR(chan)) | |
574 | return PTR_ERR(chan); | |
575 | ||
576 | ret = iio_get_channel_type(chan, &type); | |
577 | if (ret < 0) | |
578 | return ret; | |
579 | ||
580 | if (type != IIO_VOLTAGE) | |
581 | return -EINVAL; | |
582 | ||
70760e80 LW |
583 | ret = device_property_read_u32(dev, "pullup-uv", &data->pullup_uv); |
584 | if (ret) | |
585 | return dev_err_probe(dev, ret, "pullup-uv not specified\n"); | |
586 | ||
587 | ret = device_property_read_u32(dev, "pullup-ohm", &data->pullup_ohm); | |
588 | if (ret) | |
589 | return dev_err_probe(dev, ret, "pullup-ohm not specified\n"); | |
590 | ||
591 | ret = device_property_read_u32(dev, "pulldown-ohm", &data->pulldown_ohm); | |
592 | if (ret) | |
593 | return dev_err_probe(dev, ret, "pulldown-ohm not specified\n"); | |
e0149eeb | 594 | |
70760e80 | 595 | if (device_property_read_bool(dev, "connected-positive")) |
e0149eeb LW |
596 | data->connect = NTC_CONNECTED_POSITIVE; |
597 | else /* status change should be possible if not always on. */ | |
598 | data->connect = NTC_CONNECTED_GROUND; | |
599 | ||
600 | data->chan = chan; | |
601 | ||
602 | return 0; | |
603 | } | |
604 | ||
6c931ae1 | 605 | static int ntc_thermistor_probe(struct platform_device *pdev) |
f22aaaa7 | 606 | { |
48001525 | 607 | struct device *dev = &pdev->dev; |
9e8269de | 608 | const struct platform_device_id *pdev_id; |
5e7f5994 | 609 | struct device *hwmon_dev; |
f22aaaa7 | 610 | struct ntc_data *data; |
e0149eeb | 611 | int ret; |
9e8269de | 612 | |
e0149eeb LW |
613 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); |
614 | if (!data) | |
615 | return -ENOMEM; | |
f22aaaa7 | 616 | |
70760e80 | 617 | ret = ntc_thermistor_parse_props(dev, data); |
e0149eeb LW |
618 | if (ret) |
619 | return ret; | |
f22aaaa7 | 620 | |
e380095b LW |
621 | if (data->pullup_uv == 0 || |
622 | (data->pullup_ohm == 0 && data->connect == | |
209218ef | 623 | NTC_CONNECTED_GROUND) || |
e380095b | 624 | (data->pulldown_ohm == 0 && data->connect == |
209218ef | 625 | NTC_CONNECTED_POSITIVE) || |
e380095b LW |
626 | (data->connect != NTC_CONNECTED_POSITIVE && |
627 | data->connect != NTC_CONNECTED_GROUND)) { | |
209218ef | 628 | dev_err(dev, "Required data to use NTC driver not supplied.\n"); |
f22aaaa7 DK |
629 | return -EINVAL; |
630 | } | |
631 | ||
70760e80 | 632 | pdev_id = device_get_match_data(dev); |
9e8269de | 633 | |
737c086e | 634 | if (pdev_id->driver_data >= ARRAY_SIZE(ntc_type)) { |
48001525 | 635 | dev_err(dev, "Unknown device type: %lu(%s)\n", |
9e8269de | 636 | pdev_id->driver_data, pdev_id->name); |
41141e64 | 637 | return -EINVAL; |
f22aaaa7 DK |
638 | } |
639 | ||
737c086e PR |
640 | data->comp = ntc_type[pdev_id->driver_data].comp; |
641 | data->n_comp = ntc_type[pdev_id->driver_data].n_comp; | |
642 | ||
7cc7de93 GR |
643 | hwmon_dev = devm_hwmon_device_register_with_info(dev, pdev_id->name, |
644 | data, &ntc_chip_info, | |
645 | NULL); | |
5e7f5994 | 646 | if (IS_ERR(hwmon_dev)) { |
48001525 | 647 | dev_err(dev, "unable to register as hwmon device.\n"); |
5e7f5994 | 648 | return PTR_ERR(hwmon_dev); |
f22aaaa7 DK |
649 | } |
650 | ||
48001525 GR |
651 | dev_info(dev, "Thermistor type: %s successfully probed.\n", |
652 | pdev_id->name); | |
9e8269de | 653 | |
f22aaaa7 DK |
654 | return 0; |
655 | } | |
656 | ||
9f448e79 LW |
657 | static const struct of_device_id ntc_match[] = { |
658 | { .compatible = "epcos,b57330v2103", | |
659 | .data = &ntc_thermistor_id[NTC_B57330V2103]}, | |
660 | { .compatible = "epcos,b57891s0103", | |
661 | .data = &ntc_thermistor_id[NTC_B57891S0103] }, | |
662 | { .compatible = "murata,ncp03wb473", | |
663 | .data = &ntc_thermistor_id[NTC_NCP03WB473] }, | |
664 | { .compatible = "murata,ncp03wf104", | |
665 | .data = &ntc_thermistor_id[NTC_NCP03WF104] }, | |
666 | { .compatible = "murata,ncp15wb473", | |
667 | .data = &ntc_thermistor_id[NTC_NCP15WB473] }, | |
668 | { .compatible = "murata,ncp15wl333", | |
669 | .data = &ntc_thermistor_id[NTC_NCP15WL333] }, | |
670 | { .compatible = "murata,ncp15xh103", | |
671 | .data = &ntc_thermistor_id[NTC_NCP15XH103] }, | |
672 | { .compatible = "murata,ncp18wb473", | |
673 | .data = &ntc_thermistor_id[NTC_NCP18WB473] }, | |
674 | { .compatible = "murata,ncp21wb473", | |
675 | .data = &ntc_thermistor_id[NTC_NCP21WB473] }, | |
e13e979b LW |
676 | { .compatible = "samsung,1404-001221", |
677 | .data = &ntc_thermistor_id[NTC_SSG1404001221] }, | |
9f448e79 LW |
678 | |
679 | /* Usage of vendor name "ntc" is deprecated */ | |
680 | { .compatible = "ntc,ncp03wb473", | |
681 | .data = &ntc_thermistor_id[NTC_NCP03WB473] }, | |
682 | { .compatible = "ntc,ncp15wb473", | |
683 | .data = &ntc_thermistor_id[NTC_NCP15WB473] }, | |
684 | { .compatible = "ntc,ncp15wl333", | |
685 | .data = &ntc_thermistor_id[NTC_NCP15WL333] }, | |
686 | { .compatible = "ntc,ncp18wb473", | |
687 | .data = &ntc_thermistor_id[NTC_NCP18WB473] }, | |
688 | { .compatible = "ntc,ncp21wb473", | |
689 | .data = &ntc_thermistor_id[NTC_NCP21WB473] }, | |
690 | { }, | |
691 | }; | |
692 | MODULE_DEVICE_TABLE(of, ntc_match); | |
693 | ||
f22aaaa7 DK |
694 | static struct platform_driver ntc_thermistor_driver = { |
695 | .driver = { | |
696 | .name = "ntc-thermistor", | |
70760e80 | 697 | .of_match_table = ntc_match, |
f22aaaa7 DK |
698 | }, |
699 | .probe = ntc_thermistor_probe, | |
f22aaaa7 DK |
700 | .id_table = ntc_thermistor_id, |
701 | }; | |
702 | ||
25a236a5 | 703 | module_platform_driver(ntc_thermistor_driver); |
f22aaaa7 | 704 | |
ed67f087 | 705 | MODULE_DESCRIPTION("NTC Thermistor Driver"); |
f22aaaa7 DK |
706 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); |
707 | MODULE_LICENSE("GPL"); | |
708 | MODULE_ALIAS("platform:ntc-thermistor"); |