xref: /openbmc/linux/drivers/iio/accel/bma400_core.c (revision 27ab1c1c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Core IIO driver for Bosch BMA400 triaxial acceleration sensor.
4  *
5  * Copyright 2019 Dan Robertson <dan@dlrobertson.com>
6  *
7  * TODO:
8  *  - Support for power management
9  *  - Support events and interrupts
10  *  - Create channel for step count
11  *  - Create channel for sensor time
12  */
13 
14 #include <linux/bitops.h>
15 #include <linux/device.h>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/regmap.h>
22 #include <linux/regulator/consumer.h>
23 
24 #include "bma400.h"
25 
26 /*
27  * The G-range selection may be one of 2g, 4g, 8, or 16g. The scale may
28  * be selected with the acc_range bits of the ACC_CONFIG1 register.
29  * NB: This buffer is populated in the device init.
30  */
31 static int bma400_scales[8];
32 
33 /*
34  * See the ACC_CONFIG1 section of the datasheet.
35  * NB: This buffer is populated in the device init.
36  */
37 static int bma400_sample_freqs[14];
38 
39 static const int bma400_osr_range[] = { 0, 1, 3 };
40 
41 /* See the ACC_CONFIG0 section of the datasheet */
42 enum bma400_power_mode {
43 	POWER_MODE_SLEEP   = 0x00,
44 	POWER_MODE_LOW     = 0x01,
45 	POWER_MODE_NORMAL  = 0x02,
46 	POWER_MODE_INVALID = 0x03,
47 };
48 
49 struct bma400_sample_freq {
50 	int hz;
51 	int uhz;
52 };
53 
54 struct bma400_data {
55 	struct device *dev;
56 	struct regmap *regmap;
57 	struct regulator_bulk_data regulators[BMA400_NUM_REGULATORS];
58 	struct mutex mutex; /* data register lock */
59 	struct iio_mount_matrix orientation;
60 	enum bma400_power_mode power_mode;
61 	struct bma400_sample_freq sample_freq;
62 	int oversampling_ratio;
63 	int scale;
64 };
65 
66 static bool bma400_is_writable_reg(struct device *dev, unsigned int reg)
67 {
68 	switch (reg) {
69 	case BMA400_CHIP_ID_REG:
70 	case BMA400_ERR_REG:
71 	case BMA400_STATUS_REG:
72 	case BMA400_X_AXIS_LSB_REG:
73 	case BMA400_X_AXIS_MSB_REG:
74 	case BMA400_Y_AXIS_LSB_REG:
75 	case BMA400_Y_AXIS_MSB_REG:
76 	case BMA400_Z_AXIS_LSB_REG:
77 	case BMA400_Z_AXIS_MSB_REG:
78 	case BMA400_SENSOR_TIME0:
79 	case BMA400_SENSOR_TIME1:
80 	case BMA400_SENSOR_TIME2:
81 	case BMA400_EVENT_REG:
82 	case BMA400_INT_STAT0_REG:
83 	case BMA400_INT_STAT1_REG:
84 	case BMA400_INT_STAT2_REG:
85 	case BMA400_TEMP_DATA_REG:
86 	case BMA400_FIFO_LENGTH0_REG:
87 	case BMA400_FIFO_LENGTH1_REG:
88 	case BMA400_FIFO_DATA_REG:
89 	case BMA400_STEP_CNT0_REG:
90 	case BMA400_STEP_CNT1_REG:
91 	case BMA400_STEP_CNT3_REG:
92 	case BMA400_STEP_STAT_REG:
93 		return false;
94 	default:
95 		return true;
96 	}
97 }
98 
99 static bool bma400_is_volatile_reg(struct device *dev, unsigned int reg)
100 {
101 	switch (reg) {
102 	case BMA400_ERR_REG:
103 	case BMA400_STATUS_REG:
104 	case BMA400_X_AXIS_LSB_REG:
105 	case BMA400_X_AXIS_MSB_REG:
106 	case BMA400_Y_AXIS_LSB_REG:
107 	case BMA400_Y_AXIS_MSB_REG:
108 	case BMA400_Z_AXIS_LSB_REG:
109 	case BMA400_Z_AXIS_MSB_REG:
110 	case BMA400_SENSOR_TIME0:
111 	case BMA400_SENSOR_TIME1:
112 	case BMA400_SENSOR_TIME2:
113 	case BMA400_EVENT_REG:
114 	case BMA400_INT_STAT0_REG:
115 	case BMA400_INT_STAT1_REG:
116 	case BMA400_INT_STAT2_REG:
117 	case BMA400_TEMP_DATA_REG:
118 	case BMA400_FIFO_LENGTH0_REG:
119 	case BMA400_FIFO_LENGTH1_REG:
120 	case BMA400_FIFO_DATA_REG:
121 	case BMA400_STEP_CNT0_REG:
122 	case BMA400_STEP_CNT1_REG:
123 	case BMA400_STEP_CNT3_REG:
124 	case BMA400_STEP_STAT_REG:
125 		return true;
126 	default:
127 		return false;
128 	}
129 }
130 
131 const struct regmap_config bma400_regmap_config = {
132 	.reg_bits = 8,
133 	.val_bits = 8,
134 	.max_register = BMA400_CMD_REG,
135 	.cache_type = REGCACHE_RBTREE,
136 	.writeable_reg = bma400_is_writable_reg,
137 	.volatile_reg = bma400_is_volatile_reg,
138 };
139 EXPORT_SYMBOL(bma400_regmap_config);
140 
141 static const struct iio_mount_matrix *
142 bma400_accel_get_mount_matrix(const struct iio_dev *indio_dev,
143 			      const struct iio_chan_spec *chan)
144 {
145 	struct bma400_data *data = iio_priv(indio_dev);
146 
147 	return &data->orientation;
148 }
149 
150 static const struct iio_chan_spec_ext_info bma400_ext_info[] = {
151 	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bma400_accel_get_mount_matrix),
152 	{ }
153 };
154 
155 #define BMA400_ACC_CHANNEL(_axis) { \
156 	.type = IIO_ACCEL, \
157 	.modified = 1, \
158 	.channel2 = IIO_MOD_##_axis, \
159 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
160 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
161 		BIT(IIO_CHAN_INFO_SCALE) | \
162 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
163 	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
164 		BIT(IIO_CHAN_INFO_SCALE) | \
165 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
166 	.ext_info = bma400_ext_info, \
167 }
168 
169 static const struct iio_chan_spec bma400_channels[] = {
170 	BMA400_ACC_CHANNEL(X),
171 	BMA400_ACC_CHANNEL(Y),
172 	BMA400_ACC_CHANNEL(Z),
173 	{
174 		.type = IIO_TEMP,
175 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
176 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ),
177 	},
178 };
179 
180 static int bma400_get_temp_reg(struct bma400_data *data, int *val, int *val2)
181 {
182 	unsigned int raw_temp;
183 	int host_temp;
184 	int ret;
185 
186 	if (data->power_mode == POWER_MODE_SLEEP)
187 		return -EBUSY;
188 
189 	ret = regmap_read(data->regmap, BMA400_TEMP_DATA_REG, &raw_temp);
190 	if (ret)
191 		return ret;
192 
193 	host_temp = sign_extend32(raw_temp, 7);
194 	/*
195 	 * The formula for the TEMP_DATA register in the datasheet
196 	 * is: x * 0.5 + 23
197 	 */
198 	*val = (host_temp >> 1) + 23;
199 	*val2 = (host_temp & 0x1) * 500000;
200 	return IIO_VAL_INT_PLUS_MICRO;
201 }
202 
203 static int bma400_get_accel_reg(struct bma400_data *data,
204 				const struct iio_chan_spec *chan,
205 				int *val)
206 {
207 	__le16 raw_accel;
208 	int lsb_reg;
209 	int ret;
210 
211 	if (data->power_mode == POWER_MODE_SLEEP)
212 		return -EBUSY;
213 
214 	switch (chan->channel2) {
215 	case IIO_MOD_X:
216 		lsb_reg = BMA400_X_AXIS_LSB_REG;
217 		break;
218 	case IIO_MOD_Y:
219 		lsb_reg = BMA400_Y_AXIS_LSB_REG;
220 		break;
221 	case IIO_MOD_Z:
222 		lsb_reg = BMA400_Z_AXIS_LSB_REG;
223 		break;
224 	default:
225 		dev_err(data->dev, "invalid axis channel modifier\n");
226 		return -EINVAL;
227 	}
228 
229 	/* bulk read two registers, with the base being the LSB register */
230 	ret = regmap_bulk_read(data->regmap, lsb_reg, &raw_accel,
231 			       sizeof(raw_accel));
232 	if (ret)
233 		return ret;
234 
235 	*val = sign_extend32(le16_to_cpu(raw_accel), 11);
236 	return IIO_VAL_INT;
237 }
238 
239 static void bma400_output_data_rate_from_raw(int raw, unsigned int *val,
240 					     unsigned int *val2)
241 {
242 	*val = BMA400_ACC_ODR_MAX_HZ >> (BMA400_ACC_ODR_MAX_RAW - raw);
243 	if (raw > BMA400_ACC_ODR_MIN_RAW)
244 		*val2 = 0;
245 	else
246 		*val2 = 500000;
247 }
248 
249 static int bma400_get_accel_output_data_rate(struct bma400_data *data)
250 {
251 	unsigned int val;
252 	unsigned int odr;
253 	int ret;
254 
255 	switch (data->power_mode) {
256 	case POWER_MODE_LOW:
257 		/*
258 		 * Runs at a fixed rate in low-power mode. See section 4.3
259 		 * in the datasheet.
260 		 */
261 		bma400_output_data_rate_from_raw(BMA400_ACC_ODR_LP_RAW,
262 						 &data->sample_freq.hz,
263 						 &data->sample_freq.uhz);
264 		return 0;
265 	case POWER_MODE_NORMAL:
266 		/*
267 		 * In normal mode the ODR can be found in the ACC_CONFIG1
268 		 * register.
269 		 */
270 		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
271 		if (ret)
272 			goto error;
273 
274 		odr = val & BMA400_ACC_ODR_MASK;
275 		if (odr < BMA400_ACC_ODR_MIN_RAW ||
276 		    odr > BMA400_ACC_ODR_MAX_RAW) {
277 			ret = -EINVAL;
278 			goto error;
279 		}
280 
281 		bma400_output_data_rate_from_raw(odr, &data->sample_freq.hz,
282 						 &data->sample_freq.uhz);
283 		return 0;
284 	case POWER_MODE_SLEEP:
285 		data->sample_freq.hz = 0;
286 		data->sample_freq.uhz = 0;
287 		return 0;
288 	default:
289 		ret = 0;
290 		goto error;
291 	}
292 error:
293 	data->sample_freq.hz = -1;
294 	data->sample_freq.uhz = -1;
295 	return ret;
296 }
297 
298 static int bma400_set_accel_output_data_rate(struct bma400_data *data,
299 					     int hz, int uhz)
300 {
301 	unsigned int idx;
302 	unsigned int odr;
303 	unsigned int val;
304 	int ret;
305 
306 	if (hz >= BMA400_ACC_ODR_MIN_WHOLE_HZ) {
307 		if (uhz || hz > BMA400_ACC_ODR_MAX_HZ)
308 			return -EINVAL;
309 
310 		/* Note this works because MIN_WHOLE_HZ is odd */
311 		idx = __ffs(hz);
312 
313 		if (hz >> idx != BMA400_ACC_ODR_MIN_WHOLE_HZ)
314 			return -EINVAL;
315 
316 		idx += BMA400_ACC_ODR_MIN_RAW + 1;
317 	} else if (hz == BMA400_ACC_ODR_MIN_HZ && uhz == 500000) {
318 		idx = BMA400_ACC_ODR_MIN_RAW;
319 	} else {
320 		return -EINVAL;
321 	}
322 
323 	ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
324 	if (ret)
325 		return ret;
326 
327 	/* preserve the range and normal mode osr */
328 	odr = (~BMA400_ACC_ODR_MASK & val) | idx;
329 
330 	ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, odr);
331 	if (ret)
332 		return ret;
333 
334 	bma400_output_data_rate_from_raw(idx, &data->sample_freq.hz,
335 					 &data->sample_freq.uhz);
336 	return 0;
337 }
338 
339 static int bma400_get_accel_oversampling_ratio(struct bma400_data *data)
340 {
341 	unsigned int val;
342 	unsigned int osr;
343 	int ret;
344 
345 	/*
346 	 * The oversampling ratio is stored in a different register
347 	 * based on the power-mode. In normal mode the OSR is stored
348 	 * in ACC_CONFIG1. In low-power mode it is stored in
349 	 * ACC_CONFIG0.
350 	 */
351 	switch (data->power_mode) {
352 	case POWER_MODE_LOW:
353 		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val);
354 		if (ret) {
355 			data->oversampling_ratio = -1;
356 			return ret;
357 		}
358 
359 		osr = (val & BMA400_LP_OSR_MASK) >> BMA400_LP_OSR_SHIFT;
360 
361 		data->oversampling_ratio = osr;
362 		return 0;
363 	case POWER_MODE_NORMAL:
364 		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
365 		if (ret) {
366 			data->oversampling_ratio = -1;
367 			return ret;
368 		}
369 
370 		osr = (val & BMA400_NP_OSR_MASK) >> BMA400_NP_OSR_SHIFT;
371 
372 		data->oversampling_ratio = osr;
373 		return 0;
374 	case POWER_MODE_SLEEP:
375 		data->oversampling_ratio = 0;
376 		return 0;
377 	default:
378 		data->oversampling_ratio = -1;
379 		return -EINVAL;
380 	}
381 }
382 
383 static int bma400_set_accel_oversampling_ratio(struct bma400_data *data,
384 					       int val)
385 {
386 	unsigned int acc_config;
387 	int ret;
388 
389 	if (val & ~BMA400_TWO_BITS_MASK)
390 		return -EINVAL;
391 
392 	/*
393 	 * The oversampling ratio is stored in a different register
394 	 * based on the power-mode.
395 	 */
396 	switch (data->power_mode) {
397 	case POWER_MODE_LOW:
398 		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG,
399 				  &acc_config);
400 		if (ret)
401 			return ret;
402 
403 		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG,
404 				   (acc_config & ~BMA400_LP_OSR_MASK) |
405 				   (val << BMA400_LP_OSR_SHIFT));
406 		if (ret) {
407 			dev_err(data->dev, "Failed to write out OSR\n");
408 			return ret;
409 		}
410 
411 		data->oversampling_ratio = val;
412 		return 0;
413 	case POWER_MODE_NORMAL:
414 		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG,
415 				  &acc_config);
416 		if (ret)
417 			return ret;
418 
419 		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG,
420 				   (acc_config & ~BMA400_NP_OSR_MASK) |
421 				   (val << BMA400_NP_OSR_SHIFT));
422 		if (ret) {
423 			dev_err(data->dev, "Failed to write out OSR\n");
424 			return ret;
425 		}
426 
427 		data->oversampling_ratio = val;
428 		return 0;
429 	default:
430 		return -EINVAL;
431 	}
432 	return ret;
433 }
434 
435 static int bma400_accel_scale_to_raw(struct bma400_data *data,
436 				     unsigned int val)
437 {
438 	int raw;
439 
440 	if (val == 0)
441 		return -EINVAL;
442 
443 	/* Note this works because BMA400_SCALE_MIN is odd */
444 	raw = __ffs(val);
445 
446 	if (val >> raw != BMA400_SCALE_MIN)
447 		return -EINVAL;
448 
449 	return raw;
450 }
451 
452 static int bma400_get_accel_scale(struct bma400_data *data)
453 {
454 	unsigned int raw_scale;
455 	unsigned int val;
456 	int ret;
457 
458 	ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
459 	if (ret)
460 		return ret;
461 
462 	raw_scale = (val & BMA400_ACC_SCALE_MASK) >> BMA400_SCALE_SHIFT;
463 	if (raw_scale > BMA400_TWO_BITS_MASK)
464 		return -EINVAL;
465 
466 	data->scale = BMA400_SCALE_MIN << raw_scale;
467 
468 	return 0;
469 }
470 
471 static int bma400_set_accel_scale(struct bma400_data *data, unsigned int val)
472 {
473 	unsigned int acc_config;
474 	int raw;
475 	int ret;
476 
477 	ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &acc_config);
478 	if (ret)
479 		return ret;
480 
481 	raw = bma400_accel_scale_to_raw(data, val);
482 	if (raw < 0)
483 		return raw;
484 
485 	ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG,
486 			   (acc_config & ~BMA400_ACC_SCALE_MASK) |
487 			   (raw << BMA400_SCALE_SHIFT));
488 	if (ret)
489 		return ret;
490 
491 	data->scale = val;
492 	return 0;
493 }
494 
495 static int bma400_get_power_mode(struct bma400_data *data)
496 {
497 	unsigned int val;
498 	int ret;
499 
500 	ret = regmap_read(data->regmap, BMA400_STATUS_REG, &val);
501 	if (ret) {
502 		dev_err(data->dev, "Failed to read status register\n");
503 		return ret;
504 	}
505 
506 	data->power_mode = (val >> 1) & BMA400_TWO_BITS_MASK;
507 	return 0;
508 }
509 
510 static int bma400_set_power_mode(struct bma400_data *data,
511 				 enum bma400_power_mode mode)
512 {
513 	unsigned int val;
514 	int ret;
515 
516 	ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val);
517 	if (ret)
518 		return ret;
519 
520 	if (data->power_mode == mode)
521 		return 0;
522 
523 	if (mode == POWER_MODE_INVALID)
524 		return -EINVAL;
525 
526 	/* Preserve the low-power oversample ratio etc */
527 	ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG,
528 			   mode | (val & ~BMA400_TWO_BITS_MASK));
529 	if (ret) {
530 		dev_err(data->dev, "Failed to write to power-mode\n");
531 		return ret;
532 	}
533 
534 	data->power_mode = mode;
535 
536 	/*
537 	 * Update our cached osr and odr based on the new
538 	 * power-mode.
539 	 */
540 	bma400_get_accel_output_data_rate(data);
541 	bma400_get_accel_oversampling_ratio(data);
542 	return 0;
543 }
544 
545 static void bma400_init_tables(void)
546 {
547 	int raw;
548 	int i;
549 
550 	for (i = 0; i + 1 < ARRAY_SIZE(bma400_sample_freqs); i += 2) {
551 		raw = (i / 2) + 5;
552 		bma400_output_data_rate_from_raw(raw, &bma400_sample_freqs[i],
553 						 &bma400_sample_freqs[i + 1]);
554 	}
555 
556 	for (i = 0; i + 1 < ARRAY_SIZE(bma400_scales); i += 2) {
557 		raw = i / 2;
558 		bma400_scales[i] = 0;
559 		bma400_scales[i + 1] = BMA400_SCALE_MIN << raw;
560 	}
561 }
562 
563 static int bma400_init(struct bma400_data *data)
564 {
565 	unsigned int val;
566 	int ret;
567 
568 	/* Try to read chip_id register. It must return 0x90. */
569 	ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
570 	if (ret) {
571 		dev_err(data->dev, "Failed to read chip id register\n");
572 		goto out;
573 	}
574 
575 	if (val != BMA400_ID_REG_VAL) {
576 		dev_err(data->dev, "Chip ID mismatch\n");
577 		ret = -ENODEV;
578 		goto out;
579 	}
580 
581 	data->regulators[BMA400_VDD_REGULATOR].supply = "vdd";
582 	data->regulators[BMA400_VDDIO_REGULATOR].supply = "vddio";
583 	ret = devm_regulator_bulk_get(data->dev,
584 				      ARRAY_SIZE(data->regulators),
585 				      data->regulators);
586 	if (ret) {
587 		if (ret != -EPROBE_DEFER)
588 			dev_err(data->dev,
589 				"Failed to get regulators: %d\n",
590 				ret);
591 
592 		goto out;
593 	}
594 	ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
595 				    data->regulators);
596 	if (ret) {
597 		dev_err(data->dev, "Failed to enable regulators: %d\n",
598 			ret);
599 		goto out;
600 	}
601 
602 	ret = bma400_get_power_mode(data);
603 	if (ret) {
604 		dev_err(data->dev, "Failed to get the initial power-mode\n");
605 		goto err_reg_disable;
606 	}
607 
608 	if (data->power_mode != POWER_MODE_NORMAL) {
609 		ret = bma400_set_power_mode(data, POWER_MODE_NORMAL);
610 		if (ret) {
611 			dev_err(data->dev, "Failed to wake up the device\n");
612 			goto err_reg_disable;
613 		}
614 		/*
615 		 * TODO: The datasheet waits 1500us here in the example, but
616 		 * lists 2/ODR as the wakeup time.
617 		 */
618 		usleep_range(1500, 2000);
619 	}
620 
621 	bma400_init_tables();
622 
623 	ret = bma400_get_accel_output_data_rate(data);
624 	if (ret)
625 		goto err_reg_disable;
626 
627 	ret = bma400_get_accel_oversampling_ratio(data);
628 	if (ret)
629 		goto err_reg_disable;
630 
631 	ret = bma400_get_accel_scale(data);
632 	if (ret)
633 		goto err_reg_disable;
634 
635 	/*
636 	 * Once the interrupt engine is supported we might use the
637 	 * data_src_reg, but for now ensure this is set to the
638 	 * variable ODR filter selectable by the sample frequency
639 	 * channel.
640 	 */
641 	return regmap_write(data->regmap, BMA400_ACC_CONFIG2_REG, 0x00);
642 
643 err_reg_disable:
644 	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
645 			       data->regulators);
646 out:
647 	return ret;
648 }
649 
650 static int bma400_read_raw(struct iio_dev *indio_dev,
651 			   struct iio_chan_spec const *chan, int *val,
652 			   int *val2, long mask)
653 {
654 	struct bma400_data *data = iio_priv(indio_dev);
655 	int ret;
656 
657 	switch (mask) {
658 	case IIO_CHAN_INFO_PROCESSED:
659 		mutex_lock(&data->mutex);
660 		ret = bma400_get_temp_reg(data, val, val2);
661 		mutex_unlock(&data->mutex);
662 		return ret;
663 	case IIO_CHAN_INFO_RAW:
664 		mutex_lock(&data->mutex);
665 		ret = bma400_get_accel_reg(data, chan, val);
666 		mutex_unlock(&data->mutex);
667 		return ret;
668 	case IIO_CHAN_INFO_SAMP_FREQ:
669 		switch (chan->type) {
670 		case IIO_ACCEL:
671 			if (data->sample_freq.hz < 0)
672 				return -EINVAL;
673 
674 			*val = data->sample_freq.hz;
675 			*val2 = data->sample_freq.uhz;
676 			return IIO_VAL_INT_PLUS_MICRO;
677 		case IIO_TEMP:
678 			/*
679 			 * Runs at a fixed sampling frequency. See Section 4.4
680 			 * of the datasheet.
681 			 */
682 			*val = 6;
683 			*val2 = 250000;
684 			return IIO_VAL_INT_PLUS_MICRO;
685 		default:
686 			return -EINVAL;
687 		}
688 	case IIO_CHAN_INFO_SCALE:
689 		*val = 0;
690 		*val2 = data->scale;
691 		return IIO_VAL_INT_PLUS_MICRO;
692 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
693 		/*
694 		 * TODO: We could avoid this logic and returning -EINVAL here if
695 		 * we set both the low-power and normal mode OSR registers when
696 		 * we configure the device.
697 		 */
698 		if (data->oversampling_ratio < 0)
699 			return -EINVAL;
700 
701 		*val = data->oversampling_ratio;
702 		return IIO_VAL_INT;
703 	default:
704 		return -EINVAL;
705 	}
706 }
707 
708 static int bma400_read_avail(struct iio_dev *indio_dev,
709 			     struct iio_chan_spec const *chan,
710 			     const int **vals, int *type, int *length,
711 			     long mask)
712 {
713 	switch (mask) {
714 	case IIO_CHAN_INFO_SCALE:
715 		*type = IIO_VAL_INT_PLUS_MICRO;
716 		*vals = bma400_scales;
717 		*length = ARRAY_SIZE(bma400_scales);
718 		return IIO_AVAIL_LIST;
719 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
720 		*type = IIO_VAL_INT;
721 		*vals = bma400_osr_range;
722 		*length = ARRAY_SIZE(bma400_osr_range);
723 		return IIO_AVAIL_RANGE;
724 	case IIO_CHAN_INFO_SAMP_FREQ:
725 		*type = IIO_VAL_INT_PLUS_MICRO;
726 		*vals = bma400_sample_freqs;
727 		*length = ARRAY_SIZE(bma400_sample_freqs);
728 		return IIO_AVAIL_LIST;
729 	default:
730 		return -EINVAL;
731 	}
732 }
733 
734 static int bma400_write_raw(struct iio_dev *indio_dev,
735 			    struct iio_chan_spec const *chan, int val, int val2,
736 			    long mask)
737 {
738 	struct bma400_data *data = iio_priv(indio_dev);
739 	int ret;
740 
741 	switch (mask) {
742 	case IIO_CHAN_INFO_SAMP_FREQ:
743 		/*
744 		 * The sample frequency is readonly for the temperature
745 		 * register and a fixed value in low-power mode.
746 		 */
747 		if (chan->type != IIO_ACCEL)
748 			return -EINVAL;
749 
750 		mutex_lock(&data->mutex);
751 		ret = bma400_set_accel_output_data_rate(data, val, val2);
752 		mutex_unlock(&data->mutex);
753 		return ret;
754 	case IIO_CHAN_INFO_SCALE:
755 		if (val != 0 ||
756 		    val2 < BMA400_SCALE_MIN || val2 > BMA400_SCALE_MAX)
757 			return -EINVAL;
758 
759 		mutex_lock(&data->mutex);
760 		ret = bma400_set_accel_scale(data, val2);
761 		mutex_unlock(&data->mutex);
762 		return ret;
763 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
764 		mutex_lock(&data->mutex);
765 		ret = bma400_set_accel_oversampling_ratio(data, val);
766 		mutex_unlock(&data->mutex);
767 		return ret;
768 	default:
769 		return -EINVAL;
770 	}
771 }
772 
773 static int bma400_write_raw_get_fmt(struct iio_dev *indio_dev,
774 				    struct iio_chan_spec const *chan,
775 				    long mask)
776 {
777 	switch (mask) {
778 	case IIO_CHAN_INFO_SAMP_FREQ:
779 		return IIO_VAL_INT_PLUS_MICRO;
780 	case IIO_CHAN_INFO_SCALE:
781 		return IIO_VAL_INT_PLUS_MICRO;
782 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
783 		return IIO_VAL_INT;
784 	default:
785 		return -EINVAL;
786 	}
787 }
788 
789 static const struct iio_info bma400_info = {
790 	.read_raw          = bma400_read_raw,
791 	.read_avail        = bma400_read_avail,
792 	.write_raw         = bma400_write_raw,
793 	.write_raw_get_fmt = bma400_write_raw_get_fmt,
794 };
795 
796 int bma400_probe(struct device *dev, struct regmap *regmap, const char *name)
797 {
798 	struct iio_dev *indio_dev;
799 	struct bma400_data *data;
800 	int ret;
801 
802 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
803 	if (!indio_dev)
804 		return -ENOMEM;
805 
806 	data = iio_priv(indio_dev);
807 	data->regmap = regmap;
808 	data->dev = dev;
809 
810 	ret = bma400_init(data);
811 	if (ret)
812 		return ret;
813 
814 	ret = iio_read_mount_matrix(dev, "mount-matrix", &data->orientation);
815 	if (ret)
816 		return ret;
817 
818 	mutex_init(&data->mutex);
819 	indio_dev->name = name;
820 	indio_dev->info = &bma400_info;
821 	indio_dev->channels = bma400_channels;
822 	indio_dev->num_channels = ARRAY_SIZE(bma400_channels);
823 	indio_dev->modes = INDIO_DIRECT_MODE;
824 
825 	dev_set_drvdata(dev, indio_dev);
826 
827 	return iio_device_register(indio_dev);
828 }
829 EXPORT_SYMBOL(bma400_probe);
830 
831 int bma400_remove(struct device *dev)
832 {
833 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
834 	struct bma400_data *data = iio_priv(indio_dev);
835 	int ret;
836 
837 	mutex_lock(&data->mutex);
838 	ret = bma400_set_power_mode(data, POWER_MODE_SLEEP);
839 	mutex_unlock(&data->mutex);
840 
841 	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
842 			       data->regulators);
843 
844 	iio_device_unregister(indio_dev);
845 
846 	return ret;
847 }
848 EXPORT_SYMBOL(bma400_remove);
849 
850 MODULE_AUTHOR("Dan Robertson <dan@dlrobertson.com>");
851 MODULE_DESCRIPTION("Bosch BMA400 triaxial acceleration sensor core");
852 MODULE_LICENSE("GPL");
853