1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
4 * - BMI088
5 *
6 * Copyright (c) 2018-2021, Topic Embedded Products
7 */
8
9 #include <linux/delay.h>
10 #include <linux/iio/iio.h>
11 #include <linux/iio/sysfs.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/pm.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17 #include <linux/slab.h>
18 #include <asm/unaligned.h>
19
20 #include "bmi088-accel.h"
21
22 #define BMI088_ACCEL_REG_CHIP_ID 0x00
23 #define BMI088_ACCEL_REG_ERROR 0x02
24
25 #define BMI088_ACCEL_REG_INT_STATUS 0x1D
26 #define BMI088_ACCEL_INT_STATUS_BIT_DRDY BIT(7)
27
28 #define BMI088_ACCEL_REG_RESET 0x7E
29 #define BMI088_ACCEL_RESET_VAL 0xB6
30
31 #define BMI088_ACCEL_REG_PWR_CTRL 0x7D
32 #define BMI088_ACCEL_REG_PWR_CONF 0x7C
33
34 #define BMI088_ACCEL_REG_INT_MAP_DATA 0x58
35 #define BMI088_ACCEL_INT_MAP_DATA_BIT_INT1_DRDY BIT(2)
36 #define BMI088_ACCEL_INT_MAP_DATA_BIT_INT2_FWM BIT(5)
37
38 #define BMI088_ACCEL_REG_INT1_IO_CONF 0x53
39 #define BMI088_ACCEL_INT1_IO_CONF_BIT_ENABLE_OUT BIT(3)
40 #define BMI088_ACCEL_INT1_IO_CONF_BIT_LVL BIT(1)
41
42 #define BMI088_ACCEL_REG_INT2_IO_CONF 0x54
43 #define BMI088_ACCEL_INT2_IO_CONF_BIT_ENABLE_OUT BIT(3)
44 #define BMI088_ACCEL_INT2_IO_CONF_BIT_LVL BIT(1)
45
46 #define BMI088_ACCEL_REG_ACC_CONF 0x40
47 #define BMI088_ACCEL_MODE_ODR_MASK 0x0f
48
49 #define BMI088_ACCEL_REG_ACC_RANGE 0x41
50 #define BMI088_ACCEL_RANGE_3G 0x00
51 #define BMI088_ACCEL_RANGE_6G 0x01
52 #define BMI088_ACCEL_RANGE_12G 0x02
53 #define BMI088_ACCEL_RANGE_24G 0x03
54
55 #define BMI088_ACCEL_REG_TEMP 0x22
56 #define BMI088_ACCEL_REG_TEMP_SHIFT 5
57 #define BMI088_ACCEL_TEMP_UNIT 125
58 #define BMI088_ACCEL_TEMP_OFFSET 23000
59
60 #define BMI088_ACCEL_REG_XOUT_L 0x12
61 #define BMI088_ACCEL_AXIS_TO_REG(axis) \
62 (BMI088_ACCEL_REG_XOUT_L + (axis * 2))
63
64 #define BMI088_ACCEL_MAX_STARTUP_TIME_US 1000
65 #define BMI088_AUTO_SUSPEND_DELAY_MS 2000
66
67 #define BMI088_ACCEL_REG_FIFO_STATUS 0x0E
68 #define BMI088_ACCEL_REG_FIFO_CONFIG0 0x48
69 #define BMI088_ACCEL_REG_FIFO_CONFIG1 0x49
70 #define BMI088_ACCEL_REG_FIFO_DATA 0x3F
71 #define BMI088_ACCEL_FIFO_LENGTH 100
72
73 #define BMI088_ACCEL_FIFO_MODE_FIFO 0x40
74 #define BMI088_ACCEL_FIFO_MODE_STREAM 0x80
75
76 enum bmi088_accel_axis {
77 AXIS_X,
78 AXIS_Y,
79 AXIS_Z,
80 };
81
82 static const int bmi088_sample_freqs[] = {
83 12, 500000,
84 25, 0,
85 50, 0,
86 100, 0,
87 200, 0,
88 400, 0,
89 800, 0,
90 1600, 0,
91 };
92
93 /* Available OSR (over sampling rate) sets the 3dB cut-off frequency */
94 enum bmi088_osr_modes {
95 BMI088_ACCEL_MODE_OSR_NORMAL = 0xA,
96 BMI088_ACCEL_MODE_OSR_2 = 0x9,
97 BMI088_ACCEL_MODE_OSR_4 = 0x8,
98 };
99
100 /* Available ODR (output data rates) in Hz */
101 enum bmi088_odr_modes {
102 BMI088_ACCEL_MODE_ODR_12_5 = 0x5,
103 BMI088_ACCEL_MODE_ODR_25 = 0x6,
104 BMI088_ACCEL_MODE_ODR_50 = 0x7,
105 BMI088_ACCEL_MODE_ODR_100 = 0x8,
106 BMI088_ACCEL_MODE_ODR_200 = 0x9,
107 BMI088_ACCEL_MODE_ODR_400 = 0xa,
108 BMI088_ACCEL_MODE_ODR_800 = 0xb,
109 BMI088_ACCEL_MODE_ODR_1600 = 0xc,
110 };
111
112 struct bmi088_scale_info {
113 int scale;
114 u8 reg_range;
115 };
116
117 struct bmi088_accel_chip_info {
118 const char *name;
119 u8 chip_id;
120 const struct iio_chan_spec *channels;
121 int num_channels;
122 };
123
124 struct bmi088_accel_data {
125 struct regmap *regmap;
126 const struct bmi088_accel_chip_info *chip_info;
127 u8 buffer[2] ____cacheline_aligned; /* shared DMA safe buffer */
128 };
129
130 static const struct regmap_range bmi088_volatile_ranges[] = {
131 /* All registers below 0x40 are volatile, except the CHIP ID. */
132 regmap_reg_range(BMI088_ACCEL_REG_ERROR, 0x3f),
133 /* Mark the RESET as volatile too, it is self-clearing */
134 regmap_reg_range(BMI088_ACCEL_REG_RESET, BMI088_ACCEL_REG_RESET),
135 };
136
137 static const struct regmap_access_table bmi088_volatile_table = {
138 .yes_ranges = bmi088_volatile_ranges,
139 .n_yes_ranges = ARRAY_SIZE(bmi088_volatile_ranges),
140 };
141
142 const struct regmap_config bmi088_regmap_conf = {
143 .reg_bits = 8,
144 .val_bits = 8,
145 .max_register = 0x7E,
146 .volatile_table = &bmi088_volatile_table,
147 .cache_type = REGCACHE_RBTREE,
148 };
149 EXPORT_SYMBOL_NS_GPL(bmi088_regmap_conf, IIO_BMI088);
150
bmi088_accel_power_up(struct bmi088_accel_data * data)151 static int bmi088_accel_power_up(struct bmi088_accel_data *data)
152 {
153 int ret;
154
155 /* Enable accelerometer and temperature sensor */
156 ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CTRL, 0x4);
157 if (ret)
158 return ret;
159
160 /* Datasheet recommends to wait at least 5ms before communication */
161 usleep_range(5000, 6000);
162
163 /* Disable suspend mode */
164 ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CONF, 0x0);
165 if (ret)
166 return ret;
167
168 /* Recommended at least 1ms before further communication */
169 usleep_range(1000, 1200);
170
171 return 0;
172 }
173
bmi088_accel_power_down(struct bmi088_accel_data * data)174 static int bmi088_accel_power_down(struct bmi088_accel_data *data)
175 {
176 int ret;
177
178 /* Enable suspend mode */
179 ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CONF, 0x3);
180 if (ret)
181 return ret;
182
183 /* Recommended at least 1ms before further communication */
184 usleep_range(1000, 1200);
185
186 /* Disable accelerometer and temperature sensor */
187 ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CTRL, 0x0);
188 if (ret)
189 return ret;
190
191 /* Datasheet recommends to wait at least 5ms before communication */
192 usleep_range(5000, 6000);
193
194 return 0;
195 }
196
bmi088_accel_get_sample_freq(struct bmi088_accel_data * data,int * val,int * val2)197 static int bmi088_accel_get_sample_freq(struct bmi088_accel_data *data,
198 int *val, int *val2)
199 {
200 unsigned int value;
201 int ret;
202
203 ret = regmap_read(data->regmap, BMI088_ACCEL_REG_ACC_CONF,
204 &value);
205 if (ret)
206 return ret;
207
208 value &= BMI088_ACCEL_MODE_ODR_MASK;
209 value -= BMI088_ACCEL_MODE_ODR_12_5;
210 value <<= 1;
211
212 if (value >= ARRAY_SIZE(bmi088_sample_freqs) - 1)
213 return -EINVAL;
214
215 *val = bmi088_sample_freqs[value];
216 *val2 = bmi088_sample_freqs[value + 1];
217
218 return IIO_VAL_INT_PLUS_MICRO;
219 }
220
bmi088_accel_set_sample_freq(struct bmi088_accel_data * data,int val)221 static int bmi088_accel_set_sample_freq(struct bmi088_accel_data *data, int val)
222 {
223 unsigned int regval;
224 int index = 0;
225
226 while (index < ARRAY_SIZE(bmi088_sample_freqs) &&
227 bmi088_sample_freqs[index] != val)
228 index += 2;
229
230 if (index >= ARRAY_SIZE(bmi088_sample_freqs))
231 return -EINVAL;
232
233 regval = (index >> 1) + BMI088_ACCEL_MODE_ODR_12_5;
234
235 return regmap_update_bits(data->regmap, BMI088_ACCEL_REG_ACC_CONF,
236 BMI088_ACCEL_MODE_ODR_MASK, regval);
237 }
238
bmi088_accel_get_temp(struct bmi088_accel_data * data,int * val)239 static int bmi088_accel_get_temp(struct bmi088_accel_data *data, int *val)
240 {
241 int ret;
242 s16 temp;
243
244 ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_REG_TEMP,
245 &data->buffer, sizeof(__be16));
246 if (ret)
247 return ret;
248
249 /* data->buffer is cacheline aligned */
250 temp = be16_to_cpu(*(__be16 *)data->buffer);
251
252 *val = temp >> BMI088_ACCEL_REG_TEMP_SHIFT;
253
254 return IIO_VAL_INT;
255 }
256
bmi088_accel_get_axis(struct bmi088_accel_data * data,struct iio_chan_spec const * chan,int * val)257 static int bmi088_accel_get_axis(struct bmi088_accel_data *data,
258 struct iio_chan_spec const *chan,
259 int *val)
260 {
261 int ret;
262 s16 raw_val;
263
264 ret = regmap_bulk_read(data->regmap,
265 BMI088_ACCEL_AXIS_TO_REG(chan->scan_index),
266 data->buffer, sizeof(__le16));
267 if (ret)
268 return ret;
269
270 raw_val = le16_to_cpu(*(__le16 *)data->buffer);
271 *val = raw_val;
272
273 return IIO_VAL_INT;
274 }
275
bmi088_accel_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)276 static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
277 struct iio_chan_spec const *chan,
278 int *val, int *val2, long mask)
279 {
280 struct bmi088_accel_data *data = iio_priv(indio_dev);
281 struct device *dev = regmap_get_device(data->regmap);
282 int ret;
283
284 switch (mask) {
285 case IIO_CHAN_INFO_RAW:
286 switch (chan->type) {
287 case IIO_TEMP:
288 ret = pm_runtime_resume_and_get(dev);
289 if (ret)
290 return ret;
291
292 ret = bmi088_accel_get_temp(data, val);
293 goto out_read_raw_pm_put;
294 case IIO_ACCEL:
295 ret = pm_runtime_resume_and_get(dev);
296 if (ret)
297 return ret;
298
299 ret = iio_device_claim_direct_mode(indio_dev);
300 if (ret)
301 goto out_read_raw_pm_put;
302
303 ret = bmi088_accel_get_axis(data, chan, val);
304 iio_device_release_direct_mode(indio_dev);
305 if (!ret)
306 ret = IIO_VAL_INT;
307
308 goto out_read_raw_pm_put;
309 default:
310 return -EINVAL;
311 }
312 case IIO_CHAN_INFO_OFFSET:
313 switch (chan->type) {
314 case IIO_TEMP:
315 /* Offset applies before scale */
316 *val = BMI088_ACCEL_TEMP_OFFSET/BMI088_ACCEL_TEMP_UNIT;
317 return IIO_VAL_INT;
318 default:
319 return -EINVAL;
320 }
321 case IIO_CHAN_INFO_SCALE:
322 switch (chan->type) {
323 case IIO_TEMP:
324 /* 0.125 degrees per LSB */
325 *val = BMI088_ACCEL_TEMP_UNIT;
326 return IIO_VAL_INT;
327 case IIO_ACCEL:
328 ret = pm_runtime_resume_and_get(dev);
329 if (ret)
330 return ret;
331
332 ret = regmap_read(data->regmap,
333 BMI088_ACCEL_REG_ACC_RANGE, val);
334 if (ret)
335 goto out_read_raw_pm_put;
336
337 *val2 = 15 - (*val & 0x3);
338 *val = 3 * 980;
339 ret = IIO_VAL_FRACTIONAL_LOG2;
340
341 goto out_read_raw_pm_put;
342 default:
343 return -EINVAL;
344 }
345 case IIO_CHAN_INFO_SAMP_FREQ:
346 ret = pm_runtime_resume_and_get(dev);
347 if (ret)
348 return ret;
349
350 ret = bmi088_accel_get_sample_freq(data, val, val2);
351 goto out_read_raw_pm_put;
352 default:
353 break;
354 }
355
356 return -EINVAL;
357
358 out_read_raw_pm_put:
359 pm_runtime_mark_last_busy(dev);
360 pm_runtime_put_autosuspend(dev);
361
362 return ret;
363 }
364
bmi088_accel_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)365 static int bmi088_accel_read_avail(struct iio_dev *indio_dev,
366 struct iio_chan_spec const *chan,
367 const int **vals, int *type, int *length,
368 long mask)
369 {
370 switch (mask) {
371 case IIO_CHAN_INFO_SAMP_FREQ:
372 *type = IIO_VAL_INT_PLUS_MICRO;
373 *vals = bmi088_sample_freqs;
374 *length = ARRAY_SIZE(bmi088_sample_freqs);
375 return IIO_AVAIL_LIST;
376 default:
377 return -EINVAL;
378 }
379 }
380
bmi088_accel_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)381 static int bmi088_accel_write_raw(struct iio_dev *indio_dev,
382 struct iio_chan_spec const *chan,
383 int val, int val2, long mask)
384 {
385 struct bmi088_accel_data *data = iio_priv(indio_dev);
386 struct device *dev = regmap_get_device(data->regmap);
387 int ret;
388
389 switch (mask) {
390 case IIO_CHAN_INFO_SAMP_FREQ:
391 ret = pm_runtime_resume_and_get(dev);
392 if (ret)
393 return ret;
394
395 ret = bmi088_accel_set_sample_freq(data, val);
396 pm_runtime_mark_last_busy(dev);
397 pm_runtime_put_autosuspend(dev);
398 return ret;
399 default:
400 return -EINVAL;
401 }
402 }
403
404 #define BMI088_ACCEL_CHANNEL(_axis) { \
405 .type = IIO_ACCEL, \
406 .modified = 1, \
407 .channel2 = IIO_MOD_##_axis, \
408 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
409 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
410 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
411 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
412 .scan_index = AXIS_##_axis, \
413 }
414
415 static const struct iio_chan_spec bmi088_accel_channels[] = {
416 {
417 .type = IIO_TEMP,
418 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
419 BIT(IIO_CHAN_INFO_SCALE) |
420 BIT(IIO_CHAN_INFO_OFFSET),
421 .scan_index = -1,
422 },
423 BMI088_ACCEL_CHANNEL(X),
424 BMI088_ACCEL_CHANNEL(Y),
425 BMI088_ACCEL_CHANNEL(Z),
426 IIO_CHAN_SOFT_TIMESTAMP(3),
427 };
428
429 static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = {
430 [0] = {
431 .name = "bmi088a",
432 .chip_id = 0x1E,
433 .channels = bmi088_accel_channels,
434 .num_channels = ARRAY_SIZE(bmi088_accel_channels),
435 },
436 };
437
438 static const struct iio_info bmi088_accel_info = {
439 .read_raw = bmi088_accel_read_raw,
440 .write_raw = bmi088_accel_write_raw,
441 .read_avail = bmi088_accel_read_avail,
442 };
443
444 static const unsigned long bmi088_accel_scan_masks[] = {
445 BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
446 0
447 };
448
bmi088_accel_chip_init(struct bmi088_accel_data * data)449 static int bmi088_accel_chip_init(struct bmi088_accel_data *data)
450 {
451 struct device *dev = regmap_get_device(data->regmap);
452 int ret, i;
453 unsigned int val;
454
455 /* Do a dummy read to enable SPI interface, won't harm I2C */
456 regmap_read(data->regmap, BMI088_ACCEL_REG_INT_STATUS, &val);
457
458 /*
459 * Reset chip to get it in a known good state. A delay of 1ms after
460 * reset is required according to the data sheet
461 */
462 ret = regmap_write(data->regmap, BMI088_ACCEL_REG_RESET,
463 BMI088_ACCEL_RESET_VAL);
464 if (ret)
465 return ret;
466
467 usleep_range(1000, 2000);
468
469 /* Do a dummy read again after a reset to enable the SPI interface */
470 regmap_read(data->regmap, BMI088_ACCEL_REG_INT_STATUS, &val);
471
472 /* Read chip ID */
473 ret = regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
474 if (ret) {
475 dev_err(dev, "Error: Reading chip id\n");
476 return ret;
477 }
478
479 /* Validate chip ID */
480 for (i = 0; i < ARRAY_SIZE(bmi088_accel_chip_info_tbl); i++) {
481 if (bmi088_accel_chip_info_tbl[i].chip_id == val) {
482 data->chip_info = &bmi088_accel_chip_info_tbl[i];
483 break;
484 }
485 }
486 if (i == ARRAY_SIZE(bmi088_accel_chip_info_tbl)) {
487 dev_err(dev, "Invalid chip %x\n", val);
488 return -ENODEV;
489 }
490
491 return 0;
492 }
493
bmi088_accel_core_probe(struct device * dev,struct regmap * regmap,int irq,const char * name,bool block_supported)494 int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap,
495 int irq, const char *name, bool block_supported)
496 {
497 struct bmi088_accel_data *data;
498 struct iio_dev *indio_dev;
499 int ret;
500
501 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
502 if (!indio_dev)
503 return -ENOMEM;
504
505 data = iio_priv(indio_dev);
506 dev_set_drvdata(dev, indio_dev);
507
508 data->regmap = regmap;
509
510 ret = bmi088_accel_chip_init(data);
511 if (ret)
512 return ret;
513
514 indio_dev->channels = data->chip_info->channels;
515 indio_dev->num_channels = data->chip_info->num_channels;
516 indio_dev->name = name ? name : data->chip_info->name;
517 indio_dev->available_scan_masks = bmi088_accel_scan_masks;
518 indio_dev->modes = INDIO_DIRECT_MODE;
519 indio_dev->info = &bmi088_accel_info;
520
521 /* Enable runtime PM */
522 pm_runtime_get_noresume(dev);
523 pm_runtime_set_suspended(dev);
524 pm_runtime_enable(dev);
525 /* We need ~6ms to startup, so set the delay to 6 seconds */
526 pm_runtime_set_autosuspend_delay(dev, 6000);
527 pm_runtime_use_autosuspend(dev);
528 pm_runtime_put(dev);
529
530 ret = iio_device_register(indio_dev);
531 if (ret)
532 dev_err(dev, "Unable to register iio device\n");
533
534 return ret;
535 }
536 EXPORT_SYMBOL_NS_GPL(bmi088_accel_core_probe, IIO_BMI088);
537
538
bmi088_accel_core_remove(struct device * dev)539 void bmi088_accel_core_remove(struct device *dev)
540 {
541 struct iio_dev *indio_dev = dev_get_drvdata(dev);
542 struct bmi088_accel_data *data = iio_priv(indio_dev);
543
544 iio_device_unregister(indio_dev);
545
546 pm_runtime_disable(dev);
547 pm_runtime_set_suspended(dev);
548 bmi088_accel_power_down(data);
549 }
550 EXPORT_SYMBOL_NS_GPL(bmi088_accel_core_remove, IIO_BMI088);
551
bmi088_accel_runtime_suspend(struct device * dev)552 static int __maybe_unused bmi088_accel_runtime_suspend(struct device *dev)
553 {
554 struct iio_dev *indio_dev = dev_get_drvdata(dev);
555 struct bmi088_accel_data *data = iio_priv(indio_dev);
556
557 return bmi088_accel_power_down(data);
558 }
559
bmi088_accel_runtime_resume(struct device * dev)560 static int __maybe_unused bmi088_accel_runtime_resume(struct device *dev)
561 {
562 struct iio_dev *indio_dev = dev_get_drvdata(dev);
563 struct bmi088_accel_data *data = iio_priv(indio_dev);
564
565 return bmi088_accel_power_up(data);
566 }
567
568 const struct dev_pm_ops bmi088_accel_pm_ops = {
569 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
570 pm_runtime_force_resume)
571 SET_RUNTIME_PM_OPS(bmi088_accel_runtime_suspend,
572 bmi088_accel_runtime_resume, NULL)
573 };
574 EXPORT_SYMBOL_NS_GPL(bmi088_accel_pm_ops, IIO_BMI088);
575
576 MODULE_AUTHOR("Niek van Agt <niek.van.agt@topicproducts.com>");
577 MODULE_LICENSE("GPL v2");
578 MODULE_DESCRIPTION("BMI088 accelerometer driver (core)");
579