diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-30 14:57:57 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-30 14:57:57 -0400 |
commit | 464c9098bbc17b4596aa12191a7e646a28e7587a (patch) | |
tree | 1d97f02c1f071f358f0d0b5fd8e04db3b9a7a9af /drivers/hwmon/ntc_thermistor.c | |
parent | 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d (diff) | |
parent | f90be42fb383f39aa814b8e14de138da8973e5c1 (diff) |
Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging: (24 commits)
hwmon: (lm90) Refactor reading of config2 register
hwmon: (lm90) Make SA56004 detection more robust
hwmon: (lm90) Simplify handling of extended local temp register
hwmon: (pmbus) Add client driver for LM25066, LM5064, and LM5066
hwmon: (max34440) Add support for peak attributes
hwmon: (max8688) Add support for peak attributes
hwmon: (max16064) Add support for peak attributes
hwmon: (adm1275) Add support for peak attributes
hwmon: (pmbus) Add support for peak attributes
hwmon: Add new attributes to sysfs ABI
hwmon: (pmbus) Strengthen check for status register existence
hwmon: (pmbus) Add support for virtual pages
hwmon: (pmbus) Support reading and writing of word registers in device specific code
hwmon: (pmbus) Increase attribute name size
hwmon: (pmbus) Add ADP4000, NCP4200 and NCP4208 to list of supported devices
hwmon: (pmbus) Add support for VID output voltage mode
hwmon: (pmbus) Move PMBus drivers to drivers/hwmon/pmbus
hwmon: (coretemp) Add core/pkg threshold support to Coretemp
hwmon: (lm95241) Add support for LM95231
hwmon: LM95245 driver
...
Diffstat (limited to 'drivers/hwmon/ntc_thermistor.c')
-rw-r--r-- | drivers/hwmon/ntc_thermistor.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c new file mode 100644 index 000000000000..d7926f4336b5 --- /dev/null +++ b/drivers/hwmon/ntc_thermistor.c | |||
@@ -0,0 +1,453 @@ | |||
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 | |||
30 | #include <linux/platform_data/ntc_thermistor.h> | ||
31 | |||
32 | #include <linux/hwmon.h> | ||
33 | #include <linux/hwmon-sysfs.h> | ||
34 | |||
35 | struct ntc_compensation { | ||
36 | int temp_C; | ||
37 | unsigned int ohm; | ||
38 | }; | ||
39 | |||
40 | /* | ||
41 | * A compensation table should be sorted by the values of .ohm | ||
42 | * in descending order. | ||
43 | * The following compensation tables are from the specification of Murata NTC | ||
44 | * Thermistors Datasheet | ||
45 | */ | ||
46 | const struct ntc_compensation ncpXXwb473[] = { | ||
47 | { .temp_C = -40, .ohm = 1747920 }, | ||
48 | { .temp_C = -35, .ohm = 1245428 }, | ||
49 | { .temp_C = -30, .ohm = 898485 }, | ||
50 | { .temp_C = -25, .ohm = 655802 }, | ||
51 | { .temp_C = -20, .ohm = 483954 }, | ||
52 | { .temp_C = -15, .ohm = 360850 }, | ||
53 | { .temp_C = -10, .ohm = 271697 }, | ||
54 | { .temp_C = -5, .ohm = 206463 }, | ||
55 | { .temp_C = 0, .ohm = 158214 }, | ||
56 | { .temp_C = 5, .ohm = 122259 }, | ||
57 | { .temp_C = 10, .ohm = 95227 }, | ||
58 | { .temp_C = 15, .ohm = 74730 }, | ||
59 | { .temp_C = 20, .ohm = 59065 }, | ||
60 | { .temp_C = 25, .ohm = 47000 }, | ||
61 | { .temp_C = 30, .ohm = 37643 }, | ||
62 | { .temp_C = 35, .ohm = 30334 }, | ||
63 | { .temp_C = 40, .ohm = 24591 }, | ||
64 | { .temp_C = 45, .ohm = 20048 }, | ||
65 | { .temp_C = 50, .ohm = 16433 }, | ||
66 | { .temp_C = 55, .ohm = 13539 }, | ||
67 | { .temp_C = 60, .ohm = 11209 }, | ||
68 | { .temp_C = 65, .ohm = 9328 }, | ||
69 | { .temp_C = 70, .ohm = 7798 }, | ||
70 | { .temp_C = 75, .ohm = 6544 }, | ||
71 | { .temp_C = 80, .ohm = 5518 }, | ||
72 | { .temp_C = 85, .ohm = 4674 }, | ||
73 | { .temp_C = 90, .ohm = 3972 }, | ||
74 | { .temp_C = 95, .ohm = 3388 }, | ||
75 | { .temp_C = 100, .ohm = 2902 }, | ||
76 | { .temp_C = 105, .ohm = 2494 }, | ||
77 | { .temp_C = 110, .ohm = 2150 }, | ||
78 | { .temp_C = 115, .ohm = 1860 }, | ||
79 | { .temp_C = 120, .ohm = 1615 }, | ||
80 | { .temp_C = 125, .ohm = 1406 }, | ||
81 | }; | ||
82 | const struct ntc_compensation ncpXXwl333[] = { | ||
83 | { .temp_C = -40, .ohm = 1610154 }, | ||
84 | { .temp_C = -35, .ohm = 1130850 }, | ||
85 | { .temp_C = -30, .ohm = 802609 }, | ||
86 | { .temp_C = -25, .ohm = 575385 }, | ||
87 | { .temp_C = -20, .ohm = 416464 }, | ||
88 | { .temp_C = -15, .ohm = 304219 }, | ||
89 | { .temp_C = -10, .ohm = 224193 }, | ||
90 | { .temp_C = -5, .ohm = 166623 }, | ||
91 | { .temp_C = 0, .ohm = 124850 }, | ||
92 | { .temp_C = 5, .ohm = 94287 }, | ||
93 | { .temp_C = 10, .ohm = 71747 }, | ||
94 | { .temp_C = 15, .ohm = 54996 }, | ||
95 | { .temp_C = 20, .ohm = 42455 }, | ||
96 | { .temp_C = 25, .ohm = 33000 }, | ||
97 | { .temp_C = 30, .ohm = 25822 }, | ||
98 | { .temp_C = 35, .ohm = 20335 }, | ||
99 | { .temp_C = 40, .ohm = 16115 }, | ||
100 | { .temp_C = 45, .ohm = 12849 }, | ||
101 | { .temp_C = 50, .ohm = 10306 }, | ||
102 | { .temp_C = 55, .ohm = 8314 }, | ||
103 | { .temp_C = 60, .ohm = 6746 }, | ||
104 | { .temp_C = 65, .ohm = 5503 }, | ||
105 | { .temp_C = 70, .ohm = 4513 }, | ||
106 | { .temp_C = 75, .ohm = 3721 }, | ||
107 | { .temp_C = 80, .ohm = 3084 }, | ||
108 | { .temp_C = 85, .ohm = 2569 }, | ||
109 | { .temp_C = 90, .ohm = 2151 }, | ||
110 | { .temp_C = 95, .ohm = 1809 }, | ||
111 | { .temp_C = 100, .ohm = 1529 }, | ||
112 | { .temp_C = 105, .ohm = 1299 }, | ||
113 | { .temp_C = 110, .ohm = 1108 }, | ||
114 | { .temp_C = 115, .ohm = 949 }, | ||
115 | { .temp_C = 120, .ohm = 817 }, | ||
116 | { .temp_C = 125, .ohm = 707 }, | ||
117 | }; | ||
118 | |||
119 | struct ntc_data { | ||
120 | struct device *hwmon_dev; | ||
121 | struct ntc_thermistor_platform_data *pdata; | ||
122 | const struct ntc_compensation *comp; | ||
123 | struct device *dev; | ||
124 | int n_comp; | ||
125 | char name[PLATFORM_NAME_SIZE]; | ||
126 | }; | ||
127 | |||
128 | static inline u64 div64_u64_safe(u64 dividend, u64 divisor) | ||
129 | { | ||
130 | if (divisor == 0 && dividend == 0) | ||
131 | return 0; | ||
132 | if (divisor == 0) | ||
133 | return UINT_MAX; | ||
134 | return div64_u64(dividend, divisor); | ||
135 | } | ||
136 | |||
137 | static unsigned int get_ohm_of_thermistor(struct ntc_data *data, | ||
138 | unsigned int uV) | ||
139 | { | ||
140 | struct ntc_thermistor_platform_data *pdata = data->pdata; | ||
141 | u64 mV = uV / 1000; | ||
142 | u64 pmV = pdata->pullup_uV / 1000; | ||
143 | u64 N, puO, pdO; | ||
144 | puO = pdata->pullup_ohm; | ||
145 | pdO = pdata->pulldown_ohm; | ||
146 | |||
147 | if (mV == 0) { | ||
148 | if (pdata->connect == NTC_CONNECTED_POSITIVE) | ||
149 | return UINT_MAX; | ||
150 | return 0; | ||
151 | } | ||
152 | if (mV >= pmV) | ||
153 | return (pdata->connect == NTC_CONNECTED_POSITIVE) ? | ||
154 | 0 : UINT_MAX; | ||
155 | |||
156 | if (pdata->connect == NTC_CONNECTED_POSITIVE && puO == 0) | ||
157 | N = div64_u64_safe(pdO * (pmV - mV), mV); | ||
158 | else if (pdata->connect == NTC_CONNECTED_GROUND && pdO == 0) | ||
159 | N = div64_u64_safe(puO * mV, pmV - mV); | ||
160 | else if (pdata->connect == NTC_CONNECTED_POSITIVE) | ||
161 | N = div64_u64_safe(pdO * puO * (pmV - mV), | ||
162 | puO * mV - pdO * (pmV - mV)); | ||
163 | else | ||
164 | N = div64_u64_safe(pdO * puO * mV, pdO * (pmV - mV) - puO * mV); | ||
165 | |||
166 | return (unsigned int) N; | ||
167 | } | ||
168 | |||
169 | static int lookup_comp(struct ntc_data *data, | ||
170 | unsigned int ohm, int *i_low, int *i_high) | ||
171 | { | ||
172 | int start, end, mid = -1; | ||
173 | |||
174 | /* Do a binary search on compensation table */ | ||
175 | start = 0; | ||
176 | end = data->n_comp; | ||
177 | |||
178 | while (end > start) { | ||
179 | mid = start + (end - start) / 2; | ||
180 | if (data->comp[mid].ohm < ohm) | ||
181 | end = mid; | ||
182 | else if (data->comp[mid].ohm > ohm) | ||
183 | start = mid + 1; | ||
184 | else | ||
185 | break; | ||
186 | } | ||
187 | |||
188 | if (mid == 0) { | ||
189 | if (data->comp[mid].ohm > ohm) { | ||
190 | *i_high = mid; | ||
191 | *i_low = mid + 1; | ||
192 | return 0; | ||
193 | } else { | ||
194 | *i_low = mid; | ||
195 | *i_high = -1; | ||
196 | return -EINVAL; | ||
197 | } | ||
198 | } | ||
199 | if (mid == (data->n_comp - 1)) { | ||
200 | if (data->comp[mid].ohm <= ohm) { | ||
201 | *i_low = mid; | ||
202 | *i_high = mid - 1; | ||
203 | return 0; | ||
204 | } else { | ||
205 | *i_low = -1; | ||
206 | *i_high = mid; | ||
207 | return -EINVAL; | ||
208 | } | ||
209 | } | ||
210 | |||
211 | if (data->comp[mid].ohm <= ohm) { | ||
212 | *i_low = mid; | ||
213 | *i_high = mid - 1; | ||
214 | } | ||
215 | if (data->comp[mid].ohm > ohm) { | ||
216 | *i_low = mid + 1; | ||
217 | *i_high = mid; | ||
218 | } | ||
219 | |||
220 | return 0; | ||
221 | } | ||
222 | |||
223 | static int get_temp_mC(struct ntc_data *data, unsigned int ohm, int *temp) | ||
224 | { | ||
225 | int low, high; | ||
226 | int ret; | ||
227 | |||
228 | ret = lookup_comp(data, ohm, &low, &high); | ||
229 | if (ret) { | ||
230 | /* Unable to use linear approximation */ | ||
231 | if (low != -1) | ||
232 | *temp = data->comp[low].temp_C * 1000; | ||
233 | else if (high != -1) | ||
234 | *temp = data->comp[high].temp_C * 1000; | ||
235 | else | ||
236 | return ret; | ||
237 | } else { | ||
238 | *temp = data->comp[low].temp_C * 1000 + | ||
239 | ((data->comp[high].temp_C - data->comp[low].temp_C) * | ||
240 | 1000 * ((int)ohm - (int)data->comp[low].ohm)) / | ||
241 | ((int)data->comp[high].ohm - (int)data->comp[low].ohm); | ||
242 | } | ||
243 | |||
244 | return 0; | ||
245 | } | ||
246 | |||
247 | static int ntc_thermistor_read(struct ntc_data *data, int *temp) | ||
248 | { | ||
249 | int ret; | ||
250 | int read_ohm, read_uV; | ||
251 | unsigned int ohm = 0; | ||
252 | |||
253 | if (data->pdata->read_ohm) { | ||
254 | read_ohm = data->pdata->read_ohm(); | ||
255 | if (read_ohm < 0) | ||
256 | return read_ohm; | ||
257 | ohm = (unsigned int)read_ohm; | ||
258 | } | ||
259 | |||
260 | if (data->pdata->read_uV) { | ||
261 | read_uV = data->pdata->read_uV(); | ||
262 | if (read_uV < 0) | ||
263 | return read_uV; | ||
264 | ohm = get_ohm_of_thermistor(data, (unsigned int)read_uV); | ||
265 | } | ||
266 | |||
267 | ret = get_temp_mC(data, ohm, temp); | ||
268 | if (ret) { | ||
269 | dev_dbg(data->dev, "Sensor reading function not available.\n"); | ||
270 | return ret; | ||
271 | } | ||
272 | |||
273 | return 0; | ||
274 | } | ||
275 | |||
276 | static ssize_t ntc_show_name(struct device *dev, | ||
277 | struct device_attribute *attr, char *buf) | ||
278 | { | ||
279 | struct ntc_data *data = dev_get_drvdata(dev); | ||
280 | |||
281 | return sprintf(buf, "%s\n", data->name); | ||
282 | } | ||
283 | |||
284 | static ssize_t ntc_show_type(struct device *dev, | ||
285 | struct device_attribute *attr, char *buf) | ||
286 | { | ||
287 | return sprintf(buf, "4\n"); | ||
288 | } | ||
289 | |||
290 | static ssize_t ntc_show_temp(struct device *dev, | ||
291 | struct device_attribute *attr, char *buf) | ||
292 | { | ||
293 | struct ntc_data *data = dev_get_drvdata(dev); | ||
294 | int temp, ret; | ||
295 | |||
296 | ret = ntc_thermistor_read(data, &temp); | ||
297 | if (ret) | ||
298 | return ret; | ||
299 | return sprintf(buf, "%d\n", temp); | ||
300 | } | ||
301 | |||
302 | static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0); | ||
303 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0); | ||
304 | static DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL); | ||
305 | |||
306 | static struct attribute *ntc_attributes[] = { | ||
307 | &dev_attr_name.attr, | ||
308 | &sensor_dev_attr_temp1_type.dev_attr.attr, | ||
309 | &sensor_dev_attr_temp1_input.dev_attr.attr, | ||
310 | NULL, | ||
311 | }; | ||
312 | |||
313 | static const struct attribute_group ntc_attr_group = { | ||
314 | .attrs = ntc_attributes, | ||
315 | }; | ||
316 | |||
317 | static int __devinit ntc_thermistor_probe(struct platform_device *pdev) | ||
318 | { | ||
319 | struct ntc_data *data; | ||
320 | struct ntc_thermistor_platform_data *pdata = pdev->dev.platform_data; | ||
321 | int ret = 0; | ||
322 | |||
323 | if (!pdata) { | ||
324 | dev_err(&pdev->dev, "No platform init data supplied.\n"); | ||
325 | return -ENODEV; | ||
326 | } | ||
327 | |||
328 | /* Either one of the two is required. */ | ||
329 | if (!pdata->read_uV && !pdata->read_ohm) { | ||
330 | dev_err(&pdev->dev, "Both read_uV and read_ohm missing." | ||
331 | "Need either one of the two.\n"); | ||
332 | return -EINVAL; | ||
333 | } | ||
334 | |||
335 | if (pdata->read_uV && pdata->read_ohm) { | ||
336 | dev_warn(&pdev->dev, "Only one of read_uV and read_ohm " | ||
337 | "is needed; ignoring read_uV.\n"); | ||
338 | pdata->read_uV = NULL; | ||
339 | } | ||
340 | |||
341 | if (pdata->read_uV && (pdata->pullup_uV == 0 || | ||
342 | (pdata->pullup_ohm == 0 && pdata->connect == | ||
343 | NTC_CONNECTED_GROUND) || | ||
344 | (pdata->pulldown_ohm == 0 && pdata->connect == | ||
345 | NTC_CONNECTED_POSITIVE) || | ||
346 | (pdata->connect != NTC_CONNECTED_POSITIVE && | ||
347 | pdata->connect != NTC_CONNECTED_GROUND))) { | ||
348 | dev_err(&pdev->dev, "Required data to use read_uV not " | ||
349 | "supplied.\n"); | ||
350 | return -EINVAL; | ||
351 | } | ||
352 | |||
353 | data = kzalloc(sizeof(struct ntc_data), GFP_KERNEL); | ||
354 | if (!data) | ||
355 | return -ENOMEM; | ||
356 | |||
357 | data->dev = &pdev->dev; | ||
358 | data->pdata = pdata; | ||
359 | strncpy(data->name, pdev->id_entry->name, PLATFORM_NAME_SIZE); | ||
360 | |||
361 | switch (pdev->id_entry->driver_data) { | ||
362 | case TYPE_NCPXXWB473: | ||
363 | data->comp = ncpXXwb473; | ||
364 | data->n_comp = ARRAY_SIZE(ncpXXwb473); | ||
365 | break; | ||
366 | case TYPE_NCPXXWL333: | ||
367 | data->comp = ncpXXwl333; | ||
368 | data->n_comp = ARRAY_SIZE(ncpXXwl333); | ||
369 | break; | ||
370 | default: | ||
371 | dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n", | ||
372 | pdev->id_entry->driver_data, | ||
373 | pdev->id_entry->name); | ||
374 | ret = -EINVAL; | ||
375 | goto err; | ||
376 | } | ||
377 | |||
378 | platform_set_drvdata(pdev, data); | ||
379 | |||
380 | ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group); | ||
381 | if (ret) { | ||
382 | dev_err(data->dev, "unable to create sysfs files\n"); | ||
383 | goto err; | ||
384 | } | ||
385 | |||
386 | data->hwmon_dev = hwmon_device_register(data->dev); | ||
387 | if (IS_ERR_OR_NULL(data->hwmon_dev)) { | ||
388 | dev_err(data->dev, "unable to register as hwmon device.\n"); | ||
389 | ret = -EINVAL; | ||
390 | goto err_after_sysfs; | ||
391 | } | ||
392 | |||
393 | dev_info(&pdev->dev, "Thermistor %s:%d (type: %s/%lu) successfully probed.\n", | ||
394 | pdev->name, pdev->id, pdev->id_entry->name, | ||
395 | pdev->id_entry->driver_data); | ||
396 | return 0; | ||
397 | err_after_sysfs: | ||
398 | sysfs_remove_group(&data->dev->kobj, &ntc_attr_group); | ||
399 | err: | ||
400 | kfree(data); | ||
401 | return ret; | ||
402 | } | ||
403 | |||
404 | static int __devexit ntc_thermistor_remove(struct platform_device *pdev) | ||
405 | { | ||
406 | struct ntc_data *data = platform_get_drvdata(pdev); | ||
407 | |||
408 | hwmon_device_unregister(data->hwmon_dev); | ||
409 | sysfs_remove_group(&data->dev->kobj, &ntc_attr_group); | ||
410 | platform_set_drvdata(pdev, NULL); | ||
411 | |||
412 | kfree(data); | ||
413 | |||
414 | return 0; | ||
415 | } | ||
416 | |||
417 | static const struct platform_device_id ntc_thermistor_id[] = { | ||
418 | { "ncp15wb473", TYPE_NCPXXWB473 }, | ||
419 | { "ncp18wb473", TYPE_NCPXXWB473 }, | ||
420 | { "ncp21wb473", TYPE_NCPXXWB473 }, | ||
421 | { "ncp03wb473", TYPE_NCPXXWB473 }, | ||
422 | { "ncp15wl333", TYPE_NCPXXWL333 }, | ||
423 | { }, | ||
424 | }; | ||
425 | |||
426 | static struct platform_driver ntc_thermistor_driver = { | ||
427 | .driver = { | ||
428 | .name = "ntc-thermistor", | ||
429 | .owner = THIS_MODULE, | ||
430 | }, | ||
431 | .probe = ntc_thermistor_probe, | ||
432 | .remove = __devexit_p(ntc_thermistor_remove), | ||
433 | .id_table = ntc_thermistor_id, | ||
434 | }; | ||
435 | |||
436 | static int __init ntc_thermistor_init(void) | ||
437 | { | ||
438 | return platform_driver_register(&ntc_thermistor_driver); | ||
439 | } | ||
440 | |||
441 | module_init(ntc_thermistor_init); | ||
442 | |||
443 | static void __exit ntc_thermistor_cleanup(void) | ||
444 | { | ||
445 | platform_driver_unregister(&ntc_thermistor_driver); | ||
446 | } | ||
447 | |||
448 | module_exit(ntc_thermistor_cleanup); | ||
449 | |||
450 | MODULE_DESCRIPTION("NTC Thermistor Driver"); | ||
451 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | ||
452 | MODULE_LICENSE("GPL"); | ||
453 | MODULE_ALIAS("platform:ntc-thermistor"); | ||