1 /* Bosch BMI08X inertial measurement unit driver
2 *
3 * Copyright (c) 2022 Meta Platforms, Inc. and its affiliates
4 *
5 * SPDX-License-Identifier: Apache-2.0
6 */
7
8 #include <zephyr/kernel.h>
9 #include "bmi08x.h"
10
11 /*
12 * Output data rate map with allowed frequencies:
13 * freq = freq_int + freq_milli / 1000
14 *
15 * Since we don't need a finer frequency resolution than milliHz, use uint16_t
16 * to save some flash.
17 */
18 static const struct {
19 uint16_t freq_int;
20 uint16_t freq_milli; /* User should convert to uHz before setting the
21 * SENSOR_ATTR_SAMPLING_FREQUENCY attribute.
22 */
23 } bmi08x_odr_map[] = {
24 {0, 0}, {0, 780}, {1, 562}, {3, 120}, {6, 250}, {12, 500}, {25, 0},
25 {50, 0}, {100, 0}, {200, 0}, {400, 0}, {800, 0}, {1600, 0}, {3200, 0},
26 };
27
bmi08x_freq_to_odr_val(uint16_t freq_int,uint16_t freq_milli)28 int bmi08x_freq_to_odr_val(uint16_t freq_int, uint16_t freq_milli)
29 {
30 size_t i;
31
32 /* An ODR of 0 Hz is not allowed */
33 if (freq_int == 0U && freq_milli == 0U) {
34 return -EINVAL;
35 }
36
37 for (i = 0; i < ARRAY_SIZE(bmi08x_odr_map); i++) {
38 if (freq_int < bmi08x_odr_map[i].freq_int ||
39 (freq_int == bmi08x_odr_map[i].freq_int &&
40 freq_milli <= bmi08x_odr_map[i].freq_milli)) {
41 return i;
42 }
43 }
44
45 return -EINVAL;
46 }
47
bmi08x_range_to_reg_val(uint16_t range,const struct bmi08x_range * range_map,uint16_t range_map_size)48 int32_t bmi08x_range_to_reg_val(uint16_t range, const struct bmi08x_range *range_map,
49 uint16_t range_map_size)
50 {
51 int i;
52
53 for (i = 0; i < range_map_size; i++) {
54 if (range <= range_map[i].range) {
55 return range_map[i].reg_val;
56 }
57 }
58
59 return -EINVAL;
60 }
61
bmi08x_reg_val_to_range(uint8_t reg_val,const struct bmi08x_range * range_map,uint16_t range_map_size)62 int32_t bmi08x_reg_val_to_range(uint8_t reg_val, const struct bmi08x_range *range_map,
63 uint16_t range_map_size)
64 {
65 int i;
66
67 for (i = 0; i < range_map_size; i++) {
68 if (reg_val == range_map[i].reg_val) {
69 return range_map[i].range;
70 }
71 }
72
73 return -EINVAL;
74 }
75
