1 /*
2 * Copyright (c) 2024 Intel Corporation
3 * SPDX-License-Identifier: Apache-2.0
4 */
5
6 #include "bme280.h"
7 #include <math.h>
8
bme280_decoder_get_frame_count(const uint8_t * buffer,struct sensor_chan_spec chan_spec,uint16_t * frame_count)9 static int bme280_decoder_get_frame_count(const uint8_t *buffer, struct sensor_chan_spec chan_spec,
10 uint16_t *frame_count)
11 {
12 const struct bme280_encoded_data *edata = (const struct bme280_encoded_data *)buffer;
13 int32_t ret = -ENOTSUP;
14
15 if (chan_spec.chan_idx != 0) {
16 return ret;
17 }
18
19 /* This sensor lacks a FIFO; there will always only be one frame at a time. */
20 switch (chan_spec.chan_type) {
21 case SENSOR_CHAN_AMBIENT_TEMP:
22 *frame_count = edata->has_temp ? 1 : 0;
23 break;
24 case SENSOR_CHAN_PRESS:
25 *frame_count = edata->has_press ? 1 : 0;
26 break;
27 case SENSOR_CHAN_HUMIDITY:
28 *frame_count = edata->has_humidity ? 1 : 0;
29 break;
30 default:
31 return ret;
32 }
33
34 if (*frame_count > 0) {
35 ret = 0;
36 }
37
38 return ret;
39 }
40
bme280_decoder_get_size_info(struct sensor_chan_spec chan_spec,size_t * base_size,size_t * frame_size)41 static int bme280_decoder_get_size_info(struct sensor_chan_spec chan_spec, size_t *base_size,
42 size_t *frame_size)
43 {
44 switch (chan_spec.chan_type) {
45 case SENSOR_CHAN_AMBIENT_TEMP:
46 case SENSOR_CHAN_HUMIDITY:
47 case SENSOR_CHAN_PRESS:
48 *base_size = sizeof(struct sensor_q31_sample_data);
49 *frame_size = sizeof(struct sensor_q31_sample_data);
50 return 0;
51 default:
52 return -ENOTSUP;
53 }
54 }
55
bme280_decoder_decode(const uint8_t * buffer,struct sensor_chan_spec chan_spec,uint32_t * fit,uint16_t max_count,void * data_out)56 static int bme280_decoder_decode(const uint8_t *buffer, struct sensor_chan_spec chan_spec,
57 uint32_t *fit, uint16_t max_count, void *data_out)
58 {
59 const struct bme280_encoded_data *edata = (const struct bme280_encoded_data *)buffer;
60
61 if (*fit != 0) {
62 return 0;
63 }
64
65 struct sensor_q31_data *out = data_out;
66
67 out->header.base_timestamp_ns = edata->header.timestamp;
68 out->header.reading_count = 1;
69
70 switch (chan_spec.chan_type) {
71 case SENSOR_CHAN_AMBIENT_TEMP:
72 if (edata->has_temp) {
73 int32_t readq = edata->reading.comp_temp * pow(2, 31 - BME280_TEMP_SHIFT);
74 int32_t convq = BME280_TEMP_CONV * pow(2, 31 - BME280_TEMP_SHIFT);
75
76 out->readings[0].temperature =
77 (int32_t)((((int64_t)readq) << (31 - BME280_TEMP_SHIFT)) /
78 ((int64_t)convq));
79 out->shift = BME280_TEMP_SHIFT;
80 } else {
81 return -ENODATA;
82 }
83 break;
84 case SENSOR_CHAN_PRESS:
85 if (edata->has_press) {
86 int32_t readq = edata->reading.comp_press;
87 int32_t convq = BME280_PRESS_CONV_KPA * pow(2, 31 - BME280_PRESS_SHIFT);
88
89 out->readings[0].pressure =
90 (int32_t)((((int64_t)readq) << (31 - BME280_PRESS_SHIFT)) /
91 ((int64_t)convq));
92 out->shift = BME280_PRESS_SHIFT;
93 } else {
94 return -ENODATA;
95 }
96 break;
97 case SENSOR_CHAN_HUMIDITY:
98 if (edata->has_humidity) {
99 out->readings[0].humidity = edata->reading.comp_humidity;
100 out->shift = BME280_HUM_SHIFT;
101 } else {
102 return -ENODATA;
103 }
104 break;
105 default:
106 return -EINVAL;
107 }
108
109 *fit = 1;
110
111 return 1;
112 }
113
114 SENSOR_DECODER_API_DT_DEFINE() = {
115 .get_frame_count = bme280_decoder_get_frame_count,
116 .get_size_info = bme280_decoder_get_size_info,
117 .decode = bme280_decoder_decode,
118 };
119
bme280_get_decoder(const struct device * dev,const struct sensor_decoder_api ** decoder)120 int bme280_get_decoder(const struct device *dev, const struct sensor_decoder_api **decoder)
121 {
122 ARG_UNUSED(dev);
123 *decoder = &SENSOR_DECODER_NAME();
124
125 return 0;
126 }
127
