1 /*
2 * Copyright (c) 2023 Google LLC
3 * Copyright (c) 2024 Florian Weber <Florian.Weber@live.de>
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #ifndef ZEPHYR_DRIVERS_SENSOR_AKM09918C_AKM09918C_H_
8 #define ZEPHYR_DRIVERS_SENSOR_AKM09918C_AKM09918C_H_
9
10 #include <zephyr/device.h>
11 #include <zephyr/drivers/i2c.h>
12 #include <zephyr/drivers/sensor.h>
13 #include <zephyr/rtio/rtio.h>
14
15 #include "akm09918c_reg.h"
16
17 /* Time it takes to get a measurement in single-measure mode */
18 #define AKM09918C_MEASURE_TIME_US 9000
19
20 /* Conversion values */
21 #define AKM09918C_MICRO_GAUSS_PER_BIT INT64_C(1500)
22
23 /* Maximum and minimum raw register values for magnetometer data per datasheet */
24 #define AKM09918C_MAGN_MAX_DATA_REG (32752)
25 #define AKM09918C_MAGN_MIN_DATA_REG (-32752)
26
27 /* Maximum and minimum magnetometer values in microgauss. +/-32752 is the maximum range of the
28 * data registers (slightly less than the range of int16). This works out to +/- 49,128,000 uGs
29 */
30 #define AKM09918C_MAGN_MAX_MICRO_GAUSS (AKM09918C_MAGN_MAX_DATA_REG * AKM09918C_MICRO_GAUSS_PER_BIT)
31 #define AKM09918C_MAGN_MIN_MICRO_GAUSS (AKM09918C_MAGN_MIN_DATA_REG * AKM09918C_MICRO_GAUSS_PER_BIT)
32
33 struct akm09918c_data {
34 int16_t x_sample;
35 int16_t y_sample;
36 int16_t z_sample;
37 uint8_t mode;
38 #ifdef CONFIG_SENSOR_ASYNC_API
39 struct akm09918c_async_fetch_ctx {
40 struct rtio_iodev_sqe *iodev_sqe;
41 uint64_t timestamp;
42 struct k_work_delayable async_fetch_work;
43 } work_ctx;
44 #endif
45 };
46
47 struct akm09918c_config {
48 struct i2c_dt_spec i2c;
49 };
50
akm09918c_hz_to_reg(const struct sensor_value * val)51 static inline uint8_t akm09918c_hz_to_reg(const struct sensor_value *val)
52 {
53 if (val->val1 >= 100) {
54 return AKM09918C_CNTL2_CONTINUOUS_4;
55 } else if (val->val1 >= 50) {
56 return AKM09918C_CNTL2_CONTINUOUS_3;
57 } else if (val->val1 >= 20) {
58 return AKM09918C_CNTL2_CONTINUOUS_2;
59 } else if (val->val1 > 0) {
60 return AKM09918C_CNTL2_CONTINUOUS_1;
61 } else {
62 return AKM09918C_CNTL2_PWR_DOWN;
63 }
64 }
65
akm09918c_reg_to_hz(uint8_t reg,struct sensor_value * val)66 static inline void akm09918c_reg_to_hz(uint8_t reg, struct sensor_value *val)
67 {
68 val->val1 = 0;
69 val->val2 = 0;
70 switch (reg) {
71 case AKM09918C_CNTL2_CONTINUOUS_1:
72 val->val1 = 10;
73 break;
74 case AKM09918C_CNTL2_CONTINUOUS_2:
75 val->val1 = 20;
76 break;
77 case AKM09918C_CNTL2_CONTINUOUS_3:
78 val->val1 = 50;
79 break;
80 case AKM09918C_CNTL2_CONTINUOUS_4:
81 val->val1 = 100;
82 break;
83 }
84 }
85 int akm09918c_start_measurement(const struct device *dev, enum sensor_channel chan);
86
87 int akm09918c_fetch_measurement(const struct device *dev, int16_t *x, int16_t *y, int16_t *z);
88 /*
89 * RTIO types
90 */
91
92 struct akm09918c_decoder_header {
93 uint64_t timestamp;
94 } __packed;
95
96 struct akm09918c_encoded_data {
97 struct akm09918c_decoder_header header;
98 int16_t readings[3];
99 };
100
101 void akm09918_async_fetch(struct k_work *work);
102
103 int akm09918c_get_decoder(const struct device *dev, const struct sensor_decoder_api **decoder);
104
105 void akm09918c_submit(const struct device *dev, struct rtio_iodev_sqe *iodev_sqe);
106
107 #endif /* ZEPHYR_DRIVERS_SENSOR_AKM09918C_AKM09918C_H_ */
108
