1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2010 Christoph Mair <christoph.mair@gmail.com>
4 * Copyright (c) 2012 Bosch Sensortec GmbH
5 * Copyright (c) 2012 Unixphere AB
6 * Copyright (c) 2014 Intel Corporation
7 * Copyright (c) 2016 Linus Walleij <linus.walleij@linaro.org>
8 *
9 * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.
10 *
11 * Datasheet:
12 * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf
13 * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf
14 * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf
15 */
16
17 #define pr_fmt(fmt) "bmp280: " fmt
18
19 #include <linux/device.h>
20 #include <linux/module.h>
21 #include <linux/regmap.h>
22 #include <linux/delay.h>
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25 #include <linux/gpio/consumer.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h> /* For irq_get_irq_data() */
29 #include <linux/completion.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/random.h>
32
33 #include "bmp280.h"
34
35 /*
36 * These enums are used for indexing into the array of calibration
37 * coefficients for BMP180.
38 */
39 enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
40
41 struct bmp180_calib {
42 s16 AC1;
43 s16 AC2;
44 s16 AC3;
45 u16 AC4;
46 u16 AC5;
47 u16 AC6;
48 s16 B1;
49 s16 B2;
50 s16 MB;
51 s16 MC;
52 s16 MD;
53 };
54
55 /* See datasheet Section 4.2.2. */
56 struct bmp280_calib {
57 u16 T1;
58 s16 T2;
59 s16 T3;
60 u16 P1;
61 s16 P2;
62 s16 P3;
63 s16 P4;
64 s16 P5;
65 s16 P6;
66 s16 P7;
67 s16 P8;
68 s16 P9;
69 u8 H1;
70 s16 H2;
71 u8 H3;
72 s16 H4;
73 s16 H5;
74 s8 H6;
75 };
76
77 static const char *const bmp280_supply_names[] = {
78 "vddd", "vdda"
79 };
80
81 #define BMP280_NUM_SUPPLIES ARRAY_SIZE(bmp280_supply_names)
82
83 struct bmp280_data {
84 struct device *dev;
85 struct mutex lock;
86 struct regmap *regmap;
87 struct completion done;
88 bool use_eoc;
89 const struct bmp280_chip_info *chip_info;
90 union {
91 struct bmp180_calib bmp180;
92 struct bmp280_calib bmp280;
93 } calib;
94 struct regulator_bulk_data supplies[BMP280_NUM_SUPPLIES];
95 unsigned int start_up_time; /* in microseconds */
96
97 /* log of base 2 of oversampling rate */
98 u8 oversampling_press;
99 u8 oversampling_temp;
100 u8 oversampling_humid;
101
102 /*
103 * Carryover value from temperature conversion, used in pressure
104 * calculation.
105 */
106 s32 t_fine;
107 };
108
109 struct bmp280_chip_info {
110 const int *oversampling_temp_avail;
111 int num_oversampling_temp_avail;
112
113 const int *oversampling_press_avail;
114 int num_oversampling_press_avail;
115
116 const int *oversampling_humid_avail;
117 int num_oversampling_humid_avail;
118
119 int (*chip_config)(struct bmp280_data *);
120 int (*read_temp)(struct bmp280_data *, int *);
121 int (*read_press)(struct bmp280_data *, int *, int *);
122 int (*read_humid)(struct bmp280_data *, int *, int *);
123 };
124
125 /*
126 * These enums are used for indexing into the array of compensation
127 * parameters for BMP280.
128 */
129 enum { T1, T2, T3 };
130 enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
131
132 static const struct iio_chan_spec bmp280_channels[] = {
133 {
134 .type = IIO_PRESSURE,
135 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
136 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
137 },
138 {
139 .type = IIO_TEMP,
140 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
141 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
142 },
143 {
144 .type = IIO_HUMIDITYRELATIVE,
145 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
146 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
147 },
148 };
149
bmp280_read_calib(struct bmp280_data * data,struct bmp280_calib * calib,unsigned int chip)150 static int bmp280_read_calib(struct bmp280_data *data,
151 struct bmp280_calib *calib,
152 unsigned int chip)
153 {
154 int ret;
155 unsigned int tmp;
156 __le16 l16;
157 __be16 b16;
158 struct device *dev = data->dev;
159 __le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
160 __le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
161
162 /* Read temperature calibration values. */
163 ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
164 t_buf, BMP280_COMP_TEMP_REG_COUNT);
165 if (ret < 0) {
166 dev_err(data->dev,
167 "failed to read temperature calibration parameters\n");
168 return ret;
169 }
170
171 /* Toss the temperature calibration data into the entropy pool */
172 add_device_randomness(t_buf, sizeof(t_buf));
173
174 calib->T1 = le16_to_cpu(t_buf[T1]);
175 calib->T2 = le16_to_cpu(t_buf[T2]);
176 calib->T3 = le16_to_cpu(t_buf[T3]);
177
178 /* Read pressure calibration values. */
179 ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
180 p_buf, BMP280_COMP_PRESS_REG_COUNT);
181 if (ret < 0) {
182 dev_err(data->dev,
183 "failed to read pressure calibration parameters\n");
184 return ret;
185 }
186
187 /* Toss the pressure calibration data into the entropy pool */
188 add_device_randomness(p_buf, sizeof(p_buf));
189
190 calib->P1 = le16_to_cpu(p_buf[P1]);
191 calib->P2 = le16_to_cpu(p_buf[P2]);
192 calib->P3 = le16_to_cpu(p_buf[P3]);
193 calib->P4 = le16_to_cpu(p_buf[P4]);
194 calib->P5 = le16_to_cpu(p_buf[P5]);
195 calib->P6 = le16_to_cpu(p_buf[P6]);
196 calib->P7 = le16_to_cpu(p_buf[P7]);
197 calib->P8 = le16_to_cpu(p_buf[P8]);
198 calib->P9 = le16_to_cpu(p_buf[P9]);
199
200 /*
201 * Read humidity calibration values.
202 * Due to some odd register addressing we cannot just
203 * do a big bulk read. Instead, we have to read each Hx
204 * value separately and sometimes do some bit shifting...
205 * Humidity data is only available on BME280.
206 */
207 if (chip != BME280_CHIP_ID)
208 return 0;
209
210 ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &tmp);
211 if (ret < 0) {
212 dev_err(dev, "failed to read H1 comp value\n");
213 return ret;
214 }
215 calib->H1 = tmp;
216
217 ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2);
218 if (ret < 0) {
219 dev_err(dev, "failed to read H2 comp value\n");
220 return ret;
221 }
222 calib->H2 = sign_extend32(le16_to_cpu(l16), 15);
223
224 ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
225 if (ret < 0) {
226 dev_err(dev, "failed to read H3 comp value\n");
227 return ret;
228 }
229 calib->H3 = tmp;
230
231 ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2);
232 if (ret < 0) {
233 dev_err(dev, "failed to read H4 comp value\n");
234 return ret;
235 }
236 calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) |
237 (be16_to_cpu(b16) & 0xf), 11);
238
239 ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2);
240 if (ret < 0) {
241 dev_err(dev, "failed to read H5 comp value\n");
242 return ret;
243 }
244 calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11);
245
246 ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
247 if (ret < 0) {
248 dev_err(dev, "failed to read H6 comp value\n");
249 return ret;
250 }
251 calib->H6 = sign_extend32(tmp, 7);
252
253 return 0;
254 }
255 /*
256 * Returns humidity in percent, resolution is 0.01 percent. Output value of
257 * "47445" represents 47445/1024 = 46.333 %RH.
258 *
259 * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
260 */
bmp280_compensate_humidity(struct bmp280_data * data,s32 adc_humidity)261 static u32 bmp280_compensate_humidity(struct bmp280_data *data,
262 s32 adc_humidity)
263 {
264 s32 var;
265 struct bmp280_calib *calib = &data->calib.bmp280;
266
267 var = ((s32)data->t_fine) - (s32)76800;
268 var = ((((adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var))
269 + (s32)16384) >> 15) * (((((((var * calib->H6) >> 10)
270 * (((var * (s32)calib->H3) >> 11) + (s32)32768)) >> 10)
271 + (s32)2097152) * calib->H2 + 8192) >> 14);
272 var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)calib->H1) >> 4;
273
274 var = clamp_val(var, 0, 419430400);
275
276 return var >> 12;
277 };
278
279 /*
280 * Returns temperature in DegC, resolution is 0.01 DegC. Output value of
281 * "5123" equals 51.23 DegC. t_fine carries fine temperature as global
282 * value.
283 *
284 * Taken from datasheet, Section 3.11.3, "Compensation formula".
285 */
bmp280_compensate_temp(struct bmp280_data * data,s32 adc_temp)286 static s32 bmp280_compensate_temp(struct bmp280_data *data,
287 s32 adc_temp)
288 {
289 s32 var1, var2;
290 struct bmp280_calib *calib = &data->calib.bmp280;
291
292 var1 = (((adc_temp >> 3) - ((s32)calib->T1 << 1)) *
293 ((s32)calib->T2)) >> 11;
294 var2 = (((((adc_temp >> 4) - ((s32)calib->T1)) *
295 ((adc_temp >> 4) - ((s32)calib->T1))) >> 12) *
296 ((s32)calib->T3)) >> 14;
297 data->t_fine = var1 + var2;
298
299 return (data->t_fine * 5 + 128) >> 8;
300 }
301
302 /*
303 * Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24
304 * integer bits and 8 fractional bits). Output value of "24674867"
305 * represents 24674867/256 = 96386.2 Pa = 963.862 hPa
306 *
307 * Taken from datasheet, Section 3.11.3, "Compensation formula".
308 */
bmp280_compensate_press(struct bmp280_data * data,s32 adc_press)309 static u32 bmp280_compensate_press(struct bmp280_data *data,
310 s32 adc_press)
311 {
312 s64 var1, var2, p;
313 struct bmp280_calib *calib = &data->calib.bmp280;
314
315 var1 = ((s64)data->t_fine) - 128000;
316 var2 = var1 * var1 * (s64)calib->P6;
317 var2 += (var1 * (s64)calib->P5) << 17;
318 var2 += ((s64)calib->P4) << 35;
319 var1 = ((var1 * var1 * (s64)calib->P3) >> 8) +
320 ((var1 * (s64)calib->P2) << 12);
321 var1 = ((((s64)1) << 47) + var1) * ((s64)calib->P1) >> 33;
322
323 if (var1 == 0)
324 return 0;
325
326 p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
327 p = div64_s64(p, var1);
328 var1 = (((s64)calib->P9) * (p >> 13) * (p >> 13)) >> 25;
329 var2 = ((s64)(calib->P8) * p) >> 19;
330 p = ((p + var1 + var2) >> 8) + (((s64)calib->P7) << 4);
331
332 return (u32)p;
333 }
334
bmp280_read_temp(struct bmp280_data * data,int * val)335 static int bmp280_read_temp(struct bmp280_data *data,
336 int *val)
337 {
338 int ret;
339 __be32 tmp = 0;
340 s32 adc_temp, comp_temp;
341
342 ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3);
343 if (ret < 0) {
344 dev_err(data->dev, "failed to read temperature\n");
345 return ret;
346 }
347
348 adc_temp = be32_to_cpu(tmp) >> 12;
349 if (adc_temp == BMP280_TEMP_SKIPPED) {
350 /* reading was skipped */
351 dev_err(data->dev, "reading temperature skipped\n");
352 return -EIO;
353 }
354 comp_temp = bmp280_compensate_temp(data, adc_temp);
355
356 /*
357 * val might be NULL if we're called by the read_press routine,
358 * who only cares about the carry over t_fine value.
359 */
360 if (val) {
361 *val = comp_temp * 10;
362 return IIO_VAL_INT;
363 }
364
365 return 0;
366 }
367
bmp280_read_press(struct bmp280_data * data,int * val,int * val2)368 static int bmp280_read_press(struct bmp280_data *data,
369 int *val, int *val2)
370 {
371 int ret;
372 __be32 tmp = 0;
373 s32 adc_press;
374 u32 comp_press;
375
376 /* Read and compensate temperature so we get a reading of t_fine. */
377 ret = bmp280_read_temp(data, NULL);
378 if (ret < 0)
379 return ret;
380
381 ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3);
382 if (ret < 0) {
383 dev_err(data->dev, "failed to read pressure\n");
384 return ret;
385 }
386
387 adc_press = be32_to_cpu(tmp) >> 12;
388 if (adc_press == BMP280_PRESS_SKIPPED) {
389 /* reading was skipped */
390 dev_err(data->dev, "reading pressure skipped\n");
391 return -EIO;
392 }
393 comp_press = bmp280_compensate_press(data, adc_press);
394
395 *val = comp_press;
396 *val2 = 256000;
397
398 return IIO_VAL_FRACTIONAL;
399 }
400
bmp280_read_humid(struct bmp280_data * data,int * val,int * val2)401 static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
402 {
403 __be16 tmp;
404 int ret;
405 s32 adc_humidity;
406 u32 comp_humidity;
407
408 /* Read and compensate temperature so we get a reading of t_fine. */
409 ret = bmp280_read_temp(data, NULL);
410 if (ret < 0)
411 return ret;
412
413 ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp, 2);
414 if (ret < 0) {
415 dev_err(data->dev, "failed to read humidity\n");
416 return ret;
417 }
418
419 adc_humidity = be16_to_cpu(tmp);
420 if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
421 /* reading was skipped */
422 dev_err(data->dev, "reading humidity skipped\n");
423 return -EIO;
424 }
425 comp_humidity = bmp280_compensate_humidity(data, adc_humidity);
426
427 *val = comp_humidity * 1000 / 1024;
428
429 return IIO_VAL_INT;
430 }
431
bmp280_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)432 static int bmp280_read_raw(struct iio_dev *indio_dev,
433 struct iio_chan_spec const *chan,
434 int *val, int *val2, long mask)
435 {
436 int ret;
437 struct bmp280_data *data = iio_priv(indio_dev);
438
439 pm_runtime_get_sync(data->dev);
440 mutex_lock(&data->lock);
441
442 switch (mask) {
443 case IIO_CHAN_INFO_PROCESSED:
444 switch (chan->type) {
445 case IIO_HUMIDITYRELATIVE:
446 ret = data->chip_info->read_humid(data, val, val2);
447 break;
448 case IIO_PRESSURE:
449 ret = data->chip_info->read_press(data, val, val2);
450 break;
451 case IIO_TEMP:
452 ret = data->chip_info->read_temp(data, val);
453 break;
454 default:
455 ret = -EINVAL;
456 break;
457 }
458 break;
459 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
460 switch (chan->type) {
461 case IIO_HUMIDITYRELATIVE:
462 *val = 1 << data->oversampling_humid;
463 ret = IIO_VAL_INT;
464 break;
465 case IIO_PRESSURE:
466 *val = 1 << data->oversampling_press;
467 ret = IIO_VAL_INT;
468 break;
469 case IIO_TEMP:
470 *val = 1 << data->oversampling_temp;
471 ret = IIO_VAL_INT;
472 break;
473 default:
474 ret = -EINVAL;
475 break;
476 }
477 break;
478 default:
479 ret = -EINVAL;
480 break;
481 }
482
483 mutex_unlock(&data->lock);
484 pm_runtime_mark_last_busy(data->dev);
485 pm_runtime_put_autosuspend(data->dev);
486
487 return ret;
488 }
489
bmp280_write_oversampling_ratio_humid(struct bmp280_data * data,int val)490 static int bmp280_write_oversampling_ratio_humid(struct bmp280_data *data,
491 int val)
492 {
493 int i;
494 const int *avail = data->chip_info->oversampling_humid_avail;
495 const int n = data->chip_info->num_oversampling_humid_avail;
496
497 for (i = 0; i < n; i++) {
498 if (avail[i] == val) {
499 data->oversampling_humid = ilog2(val);
500
501 return data->chip_info->chip_config(data);
502 }
503 }
504 return -EINVAL;
505 }
506
bmp280_write_oversampling_ratio_temp(struct bmp280_data * data,int val)507 static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
508 int val)
509 {
510 int i;
511 const int *avail = data->chip_info->oversampling_temp_avail;
512 const int n = data->chip_info->num_oversampling_temp_avail;
513
514 for (i = 0; i < n; i++) {
515 if (avail[i] == val) {
516 data->oversampling_temp = ilog2(val);
517
518 return data->chip_info->chip_config(data);
519 }
520 }
521 return -EINVAL;
522 }
523
bmp280_write_oversampling_ratio_press(struct bmp280_data * data,int val)524 static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
525 int val)
526 {
527 int i;
528 const int *avail = data->chip_info->oversampling_press_avail;
529 const int n = data->chip_info->num_oversampling_press_avail;
530
531 for (i = 0; i < n; i++) {
532 if (avail[i] == val) {
533 data->oversampling_press = ilog2(val);
534
535 return data->chip_info->chip_config(data);
536 }
537 }
538 return -EINVAL;
539 }
540
bmp280_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)541 static int bmp280_write_raw(struct iio_dev *indio_dev,
542 struct iio_chan_spec const *chan,
543 int val, int val2, long mask)
544 {
545 int ret = 0;
546 struct bmp280_data *data = iio_priv(indio_dev);
547
548 switch (mask) {
549 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
550 pm_runtime_get_sync(data->dev);
551 mutex_lock(&data->lock);
552 switch (chan->type) {
553 case IIO_HUMIDITYRELATIVE:
554 ret = bmp280_write_oversampling_ratio_humid(data, val);
555 break;
556 case IIO_PRESSURE:
557 ret = bmp280_write_oversampling_ratio_press(data, val);
558 break;
559 case IIO_TEMP:
560 ret = bmp280_write_oversampling_ratio_temp(data, val);
561 break;
562 default:
563 ret = -EINVAL;
564 break;
565 }
566 mutex_unlock(&data->lock);
567 pm_runtime_mark_last_busy(data->dev);
568 pm_runtime_put_autosuspend(data->dev);
569 break;
570 default:
571 return -EINVAL;
572 }
573
574 return ret;
575 }
576
bmp280_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)577 static int bmp280_read_avail(struct iio_dev *indio_dev,
578 struct iio_chan_spec const *chan,
579 const int **vals, int *type, int *length,
580 long mask)
581 {
582 struct bmp280_data *data = iio_priv(indio_dev);
583
584 switch (mask) {
585 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
586 switch (chan->type) {
587 case IIO_PRESSURE:
588 *vals = data->chip_info->oversampling_press_avail;
589 *length = data->chip_info->num_oversampling_press_avail;
590 break;
591 case IIO_TEMP:
592 *vals = data->chip_info->oversampling_temp_avail;
593 *length = data->chip_info->num_oversampling_temp_avail;
594 break;
595 default:
596 return -EINVAL;
597 }
598 *type = IIO_VAL_INT;
599 return IIO_AVAIL_LIST;
600 default:
601 return -EINVAL;
602 }
603 }
604
605 static const struct iio_info bmp280_info = {
606 .read_raw = &bmp280_read_raw,
607 .read_avail = &bmp280_read_avail,
608 .write_raw = &bmp280_write_raw,
609 };
610
bmp280_chip_config(struct bmp280_data * data)611 static int bmp280_chip_config(struct bmp280_data *data)
612 {
613 int ret;
614 u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
615 BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
616
617 ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS,
618 BMP280_OSRS_TEMP_MASK |
619 BMP280_OSRS_PRESS_MASK |
620 BMP280_MODE_MASK,
621 osrs | BMP280_MODE_NORMAL);
622 if (ret < 0) {
623 dev_err(data->dev,
624 "failed to write ctrl_meas register\n");
625 return ret;
626 }
627
628 ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG,
629 BMP280_FILTER_MASK,
630 BMP280_FILTER_4X);
631 if (ret < 0) {
632 dev_err(data->dev,
633 "failed to write config register\n");
634 return ret;
635 }
636
637 return ret;
638 }
639
640 static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
641
642 static const struct bmp280_chip_info bmp280_chip_info = {
643 .oversampling_temp_avail = bmp280_oversampling_avail,
644 .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
645
646 .oversampling_press_avail = bmp280_oversampling_avail,
647 .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
648
649 .chip_config = bmp280_chip_config,
650 .read_temp = bmp280_read_temp,
651 .read_press = bmp280_read_press,
652 };
653
bme280_chip_config(struct bmp280_data * data)654 static int bme280_chip_config(struct bmp280_data *data)
655 {
656 int ret;
657 u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1);
658
659 /*
660 * Oversampling of humidity must be set before oversampling of
661 * temperature/pressure is set to become effective.
662 */
663 ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY,
664 BMP280_OSRS_HUMIDITY_MASK, osrs);
665
666 if (ret < 0)
667 return ret;
668
669 return bmp280_chip_config(data);
670 }
671
672 static const struct bmp280_chip_info bme280_chip_info = {
673 .oversampling_temp_avail = bmp280_oversampling_avail,
674 .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
675
676 .oversampling_press_avail = bmp280_oversampling_avail,
677 .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
678
679 .oversampling_humid_avail = bmp280_oversampling_avail,
680 .num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail),
681
682 .chip_config = bme280_chip_config,
683 .read_temp = bmp280_read_temp,
684 .read_press = bmp280_read_press,
685 .read_humid = bmp280_read_humid,
686 };
687
bmp180_measure(struct bmp280_data * data,u8 ctrl_meas)688 static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
689 {
690 int ret;
691 const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
692 unsigned int delay_us;
693 unsigned int ctrl;
694
695 if (data->use_eoc)
696 reinit_completion(&data->done);
697
698 ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
699 if (ret)
700 return ret;
701
702 if (data->use_eoc) {
703 /*
704 * If we have a completion interrupt, use it, wait up to
705 * 100ms. The longest conversion time listed is 76.5 ms for
706 * advanced resolution mode.
707 */
708 ret = wait_for_completion_timeout(&data->done,
709 1 + msecs_to_jiffies(100));
710 if (!ret)
711 dev_err(data->dev, "timeout waiting for completion\n");
712 } else {
713 if (ctrl_meas == BMP180_MEAS_TEMP)
714 delay_us = 4500;
715 else
716 delay_us =
717 conversion_time_max[data->oversampling_press];
718
719 usleep_range(delay_us, delay_us + 1000);
720 }
721
722 ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
723 if (ret)
724 return ret;
725
726 /* The value of this bit reset to "0" after conversion is complete */
727 if (ctrl & BMP180_MEAS_SCO)
728 return -EIO;
729
730 return 0;
731 }
732
bmp180_read_adc_temp(struct bmp280_data * data,int * val)733 static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
734 {
735 __be16 tmp;
736 int ret;
737
738 ret = bmp180_measure(data, BMP180_MEAS_TEMP);
739 if (ret)
740 return ret;
741
742 ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2);
743 if (ret)
744 return ret;
745
746 *val = be16_to_cpu(tmp);
747
748 return 0;
749 }
750
bmp180_read_calib(struct bmp280_data * data,struct bmp180_calib * calib)751 static int bmp180_read_calib(struct bmp280_data *data,
752 struct bmp180_calib *calib)
753 {
754 int ret;
755 int i;
756 __be16 buf[BMP180_REG_CALIB_COUNT / 2];
757
758 ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
759 sizeof(buf));
760
761 if (ret < 0)
762 return ret;
763
764 /* None of the words has the value 0 or 0xFFFF */
765 for (i = 0; i < ARRAY_SIZE(buf); i++) {
766 if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
767 return -EIO;
768 }
769
770 /* Toss the calibration data into the entropy pool */
771 add_device_randomness(buf, sizeof(buf));
772
773 calib->AC1 = be16_to_cpu(buf[AC1]);
774 calib->AC2 = be16_to_cpu(buf[AC2]);
775 calib->AC3 = be16_to_cpu(buf[AC3]);
776 calib->AC4 = be16_to_cpu(buf[AC4]);
777 calib->AC5 = be16_to_cpu(buf[AC5]);
778 calib->AC6 = be16_to_cpu(buf[AC6]);
779 calib->B1 = be16_to_cpu(buf[B1]);
780 calib->B2 = be16_to_cpu(buf[B2]);
781 calib->MB = be16_to_cpu(buf[MB]);
782 calib->MC = be16_to_cpu(buf[MC]);
783 calib->MD = be16_to_cpu(buf[MD]);
784
785 return 0;
786 }
787
788 /*
789 * Returns temperature in DegC, resolution is 0.1 DegC.
790 * t_fine carries fine temperature as global value.
791 *
792 * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
793 */
bmp180_compensate_temp(struct bmp280_data * data,s32 adc_temp)794 static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
795 {
796 s32 x1, x2;
797 struct bmp180_calib *calib = &data->calib.bmp180;
798
799 x1 = ((adc_temp - calib->AC6) * calib->AC5) >> 15;
800 x2 = (calib->MC << 11) / (x1 + calib->MD);
801 data->t_fine = x1 + x2;
802
803 return (data->t_fine + 8) >> 4;
804 }
805
bmp180_read_temp(struct bmp280_data * data,int * val)806 static int bmp180_read_temp(struct bmp280_data *data, int *val)
807 {
808 int ret;
809 s32 adc_temp, comp_temp;
810
811 ret = bmp180_read_adc_temp(data, &adc_temp);
812 if (ret)
813 return ret;
814
815 comp_temp = bmp180_compensate_temp(data, adc_temp);
816
817 /*
818 * val might be NULL if we're called by the read_press routine,
819 * who only cares about the carry over t_fine value.
820 */
821 if (val) {
822 *val = comp_temp * 100;
823 return IIO_VAL_INT;
824 }
825
826 return 0;
827 }
828
bmp180_read_adc_press(struct bmp280_data * data,int * val)829 static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
830 {
831 int ret;
832 __be32 tmp = 0;
833 u8 oss = data->oversampling_press;
834
835 ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
836 if (ret)
837 return ret;
838
839 ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3);
840 if (ret)
841 return ret;
842
843 *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
844
845 return 0;
846 }
847
848 /*
849 * Returns pressure in Pa, resolution is 1 Pa.
850 *
851 * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
852 */
bmp180_compensate_press(struct bmp280_data * data,s32 adc_press)853 static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
854 {
855 s32 x1, x2, x3, p;
856 s32 b3, b6;
857 u32 b4, b7;
858 s32 oss = data->oversampling_press;
859 struct bmp180_calib *calib = &data->calib.bmp180;
860
861 b6 = data->t_fine - 4000;
862 x1 = (calib->B2 * (b6 * b6 >> 12)) >> 11;
863 x2 = calib->AC2 * b6 >> 11;
864 x3 = x1 + x2;
865 b3 = ((((s32)calib->AC1 * 4 + x3) << oss) + 2) / 4;
866 x1 = calib->AC3 * b6 >> 13;
867 x2 = (calib->B1 * ((b6 * b6) >> 12)) >> 16;
868 x3 = (x1 + x2 + 2) >> 2;
869 b4 = calib->AC4 * (u32)(x3 + 32768) >> 15;
870 b7 = ((u32)adc_press - b3) * (50000 >> oss);
871 if (b7 < 0x80000000)
872 p = (b7 * 2) / b4;
873 else
874 p = (b7 / b4) * 2;
875
876 x1 = (p >> 8) * (p >> 8);
877 x1 = (x1 * 3038) >> 16;
878 x2 = (-7357 * p) >> 16;
879
880 return p + ((x1 + x2 + 3791) >> 4);
881 }
882
bmp180_read_press(struct bmp280_data * data,int * val,int * val2)883 static int bmp180_read_press(struct bmp280_data *data,
884 int *val, int *val2)
885 {
886 int ret;
887 s32 adc_press;
888 u32 comp_press;
889
890 /* Read and compensate temperature so we get a reading of t_fine. */
891 ret = bmp180_read_temp(data, NULL);
892 if (ret)
893 return ret;
894
895 ret = bmp180_read_adc_press(data, &adc_press);
896 if (ret)
897 return ret;
898
899 comp_press = bmp180_compensate_press(data, adc_press);
900
901 *val = comp_press;
902 *val2 = 1000;
903
904 return IIO_VAL_FRACTIONAL;
905 }
906
bmp180_chip_config(struct bmp280_data * data)907 static int bmp180_chip_config(struct bmp280_data *data)
908 {
909 return 0;
910 }
911
912 static const int bmp180_oversampling_temp_avail[] = { 1 };
913 static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
914
915 static const struct bmp280_chip_info bmp180_chip_info = {
916 .oversampling_temp_avail = bmp180_oversampling_temp_avail,
917 .num_oversampling_temp_avail =
918 ARRAY_SIZE(bmp180_oversampling_temp_avail),
919
920 .oversampling_press_avail = bmp180_oversampling_press_avail,
921 .num_oversampling_press_avail =
922 ARRAY_SIZE(bmp180_oversampling_press_avail),
923
924 .chip_config = bmp180_chip_config,
925 .read_temp = bmp180_read_temp,
926 .read_press = bmp180_read_press,
927 };
928
bmp085_eoc_irq(int irq,void * d)929 static irqreturn_t bmp085_eoc_irq(int irq, void *d)
930 {
931 struct bmp280_data *data = d;
932
933 complete(&data->done);
934
935 return IRQ_HANDLED;
936 }
937
bmp085_fetch_eoc_irq(struct device * dev,const char * name,int irq,struct bmp280_data * data)938 static int bmp085_fetch_eoc_irq(struct device *dev,
939 const char *name,
940 int irq,
941 struct bmp280_data *data)
942 {
943 unsigned long irq_trig;
944 int ret;
945
946 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
947 if (irq_trig != IRQF_TRIGGER_RISING) {
948 dev_err(dev, "non-rising trigger given for EOC interrupt, trying to enforce it\n");
949 irq_trig = IRQF_TRIGGER_RISING;
950 }
951
952 init_completion(&data->done);
953
954 ret = devm_request_threaded_irq(dev,
955 irq,
956 bmp085_eoc_irq,
957 NULL,
958 irq_trig,
959 name,
960 data);
961 if (ret) {
962 /* Bail out without IRQ but keep the driver in place */
963 dev_err(dev, "unable to request DRDY IRQ\n");
964 return 0;
965 }
966
967 data->use_eoc = true;
968 return 0;
969 }
970
bmp280_pm_disable(void * data)971 static void bmp280_pm_disable(void *data)
972 {
973 struct device *dev = data;
974
975 pm_runtime_get_sync(dev);
976 pm_runtime_put_noidle(dev);
977 pm_runtime_disable(dev);
978 }
979
bmp280_regulators_disable(void * data)980 static void bmp280_regulators_disable(void *data)
981 {
982 struct regulator_bulk_data *supplies = data;
983
984 regulator_bulk_disable(BMP280_NUM_SUPPLIES, supplies);
985 }
986
bmp280_common_probe(struct device * dev,struct regmap * regmap,unsigned int chip,const char * name,int irq)987 int bmp280_common_probe(struct device *dev,
988 struct regmap *regmap,
989 unsigned int chip,
990 const char *name,
991 int irq)
992 {
993 int ret;
994 struct iio_dev *indio_dev;
995 struct bmp280_data *data;
996 unsigned int chip_id;
997 struct gpio_desc *gpiod;
998
999 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
1000 if (!indio_dev)
1001 return -ENOMEM;
1002
1003 data = iio_priv(indio_dev);
1004 mutex_init(&data->lock);
1005 data->dev = dev;
1006
1007 indio_dev->name = name;
1008 indio_dev->channels = bmp280_channels;
1009 indio_dev->info = &bmp280_info;
1010 indio_dev->modes = INDIO_DIRECT_MODE;
1011
1012 switch (chip) {
1013 case BMP180_CHIP_ID:
1014 indio_dev->num_channels = 2;
1015 data->chip_info = &bmp180_chip_info;
1016 data->oversampling_press = ilog2(8);
1017 data->oversampling_temp = ilog2(1);
1018 data->start_up_time = 10000;
1019 break;
1020 case BMP280_CHIP_ID:
1021 indio_dev->num_channels = 2;
1022 data->chip_info = &bmp280_chip_info;
1023 data->oversampling_press = ilog2(16);
1024 data->oversampling_temp = ilog2(2);
1025 data->start_up_time = 2000;
1026 break;
1027 case BME280_CHIP_ID:
1028 indio_dev->num_channels = 3;
1029 data->chip_info = &bme280_chip_info;
1030 data->oversampling_press = ilog2(16);
1031 data->oversampling_humid = ilog2(16);
1032 data->oversampling_temp = ilog2(2);
1033 data->start_up_time = 2000;
1034 break;
1035 default:
1036 return -EINVAL;
1037 }
1038
1039 /* Bring up regulators */
1040 regulator_bulk_set_supply_names(data->supplies,
1041 bmp280_supply_names,
1042 BMP280_NUM_SUPPLIES);
1043
1044 ret = devm_regulator_bulk_get(dev,
1045 BMP280_NUM_SUPPLIES, data->supplies);
1046 if (ret) {
1047 dev_err(dev, "failed to get regulators\n");
1048 return ret;
1049 }
1050
1051 ret = regulator_bulk_enable(BMP280_NUM_SUPPLIES, data->supplies);
1052 if (ret) {
1053 dev_err(dev, "failed to enable regulators\n");
1054 return ret;
1055 }
1056
1057 ret = devm_add_action_or_reset(dev, bmp280_regulators_disable,
1058 data->supplies);
1059 if (ret)
1060 return ret;
1061
1062 /* Wait to make sure we started up properly */
1063 usleep_range(data->start_up_time, data->start_up_time + 100);
1064
1065 /* Bring chip out of reset if there is an assigned GPIO line */
1066 gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1067 /* Deassert the signal */
1068 if (gpiod) {
1069 dev_info(dev, "release reset\n");
1070 gpiod_set_value(gpiod, 0);
1071 }
1072
1073 data->regmap = regmap;
1074 ret = regmap_read(regmap, BMP280_REG_ID, &chip_id);
1075 if (ret < 0)
1076 return ret;
1077 if (chip_id != chip) {
1078 dev_err(dev, "bad chip id: expected %x got %x\n",
1079 chip, chip_id);
1080 return -EINVAL;
1081 }
1082
1083 ret = data->chip_info->chip_config(data);
1084 if (ret < 0)
1085 return ret;
1086
1087 dev_set_drvdata(dev, indio_dev);
1088
1089 /*
1090 * Some chips have calibration parameters "programmed into the devices'
1091 * non-volatile memory during production". Let's read them out at probe
1092 * time once. They will not change.
1093 */
1094 if (chip_id == BMP180_CHIP_ID) {
1095 ret = bmp180_read_calib(data, &data->calib.bmp180);
1096 if (ret < 0) {
1097 dev_err(data->dev,
1098 "failed to read calibration coefficients\n");
1099 return ret;
1100 }
1101 } else if (chip_id == BMP280_CHIP_ID || chip_id == BME280_CHIP_ID) {
1102 ret = bmp280_read_calib(data, &data->calib.bmp280, chip_id);
1103 if (ret < 0) {
1104 dev_err(data->dev,
1105 "failed to read calibration coefficients\n");
1106 return ret;
1107 }
1108 }
1109
1110 /*
1111 * Attempt to grab an optional EOC IRQ - only the BMP085 has this
1112 * however as it happens, the BMP085 shares the chip ID of BMP180
1113 * so we look for an IRQ if we have that.
1114 */
1115 if (irq > 0 || (chip_id == BMP180_CHIP_ID)) {
1116 ret = bmp085_fetch_eoc_irq(dev, name, irq, data);
1117 if (ret)
1118 return ret;
1119 }
1120
1121 /* Enable runtime PM */
1122 pm_runtime_get_noresume(dev);
1123 pm_runtime_set_active(dev);
1124 pm_runtime_enable(dev);
1125 /*
1126 * Set autosuspend to two orders of magnitude larger than the
1127 * start-up time.
1128 */
1129 pm_runtime_set_autosuspend_delay(dev, data->start_up_time / 10);
1130 pm_runtime_use_autosuspend(dev);
1131 pm_runtime_put(dev);
1132
1133 ret = devm_add_action_or_reset(dev, bmp280_pm_disable, dev);
1134 if (ret)
1135 return ret;
1136
1137 return devm_iio_device_register(dev, indio_dev);
1138 }
1139 EXPORT_SYMBOL(bmp280_common_probe);
1140
1141 #ifdef CONFIG_PM
bmp280_runtime_suspend(struct device * dev)1142 static int bmp280_runtime_suspend(struct device *dev)
1143 {
1144 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1145 struct bmp280_data *data = iio_priv(indio_dev);
1146
1147 return regulator_bulk_disable(BMP280_NUM_SUPPLIES, data->supplies);
1148 }
1149
bmp280_runtime_resume(struct device * dev)1150 static int bmp280_runtime_resume(struct device *dev)
1151 {
1152 struct iio_dev *indio_dev = dev_get_drvdata(dev);
1153 struct bmp280_data *data = iio_priv(indio_dev);
1154 int ret;
1155
1156 ret = regulator_bulk_enable(BMP280_NUM_SUPPLIES, data->supplies);
1157 if (ret)
1158 return ret;
1159 usleep_range(data->start_up_time, data->start_up_time + 100);
1160 return data->chip_info->chip_config(data);
1161 }
1162 #endif /* CONFIG_PM */
1163
1164 const struct dev_pm_ops bmp280_dev_pm_ops = {
1165 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1166 pm_runtime_force_resume)
1167 SET_RUNTIME_PM_OPS(bmp280_runtime_suspend,
1168 bmp280_runtime_resume, NULL)
1169 };
1170 EXPORT_SYMBOL(bmp280_dev_pm_ops);
1171
1172 MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
1173 MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
1174 MODULE_LICENSE("GPL v2");
1175