1 /*
2 * Copyright (c) 2023 Benjamin Cabé <benjamin@zephyrproject.org>
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #define DT_DRV_COMPAT seeed_hm330x
8
9 #include <zephyr/drivers/i2c.h>
10 #include <zephyr/drivers/sensor.h>
11 #include <zephyr/init.h>
12 #include <zephyr/logging/log.h>
13 #include <zephyr/sys/__assert.h>
14
15 LOG_MODULE_REGISTER(HM3301, CONFIG_SENSOR_LOG_LEVEL);
16
17 #define HM330X_SELECT_COMM_CMD 0X88
18
19 #define HM330X_PM_1_0_ATM 10
20 #define HM330X_PM_2_5_ATM 12
21 #define HM330X_PM_10_ATM 14
22
23 #define HM330X_FRAME_LEN 29
24
25 struct hm330x_data {
26 uint16_t pm_1_0_sample;
27 uint16_t pm_2_5_sample;
28 uint16_t pm_10_sample;
29 };
30
31 struct hm330x_config {
32 struct i2c_dt_spec i2c;
33 };
34
hm330x_sample_fetch(const struct device * dev,enum sensor_channel chan)35 static int hm330x_sample_fetch(const struct device *dev,
36 enum sensor_channel chan)
37 {
38 struct hm330x_data *drv_data = dev->data;
39 const struct hm330x_config *config = dev->config;
40 uint8_t buf[HM330X_FRAME_LEN];
41 uint8_t checksum = 0;
42
43 __ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
44
45 if (i2c_burst_read_dt(&config->i2c,
46 0, buf, HM330X_FRAME_LEN) < 0) {
47 return -EIO;
48 }
49
50 drv_data->pm_1_0_sample = (buf[HM330X_PM_1_0_ATM] << 8) | buf[HM330X_PM_1_0_ATM + 1];
51 drv_data->pm_2_5_sample = (buf[HM330X_PM_2_5_ATM] << 8) | buf[HM330X_PM_2_5_ATM + 1];
52 drv_data->pm_10_sample = (buf[HM330X_PM_10_ATM] << 8) | buf[HM330X_PM_10_ATM + 1];
53
54 for (int i = 0; i < HM330X_FRAME_LEN - 1; i++) {
55 checksum += buf[i];
56 }
57 if (checksum != buf[HM330X_FRAME_LEN - 1]) {
58 LOG_ERR("Checksum error");
59 return -EBADMSG;
60 }
61
62 return 0;
63 }
64
hm330x_channel_get(const struct device * dev,enum sensor_channel chan,struct sensor_value * val)65 static int hm330x_channel_get(const struct device *dev,
66 enum sensor_channel chan,
67 struct sensor_value *val)
68 {
69 struct hm330x_data *drv_data = dev->data;
70
71 if (chan == SENSOR_CHAN_PM_1_0) {
72 val->val1 = drv_data->pm_1_0_sample;
73 val->val2 = 0;
74 } else if (chan == SENSOR_CHAN_PM_2_5) {
75 val->val1 = drv_data->pm_2_5_sample;
76 val->val2 = 0;
77 } else if (chan == SENSOR_CHAN_PM_10) {
78 val->val1 = drv_data->pm_10_sample;
79 val->val2 = 0;
80 } else {
81 return -ENOTSUP;
82 }
83
84 return 0;
85 }
86
87 static const struct sensor_driver_api hm330x_driver_api = {
88 .sample_fetch = hm330x_sample_fetch,
89 .channel_get = hm330x_channel_get
90 };
91
hm330x_init(const struct device * dev)92 int hm330x_init(const struct device *dev)
93 {
94 const struct hm330x_config *config = dev->config;
95
96 if (!i2c_is_ready_dt(&config->i2c)) {
97 LOG_ERR("I2C bus device not ready");
98 return -ENODEV;
99 }
100
101 /** Enable I2C communications (module defaults to UART) */
102 if (i2c_reg_write_byte_dt(&config->i2c, 0, HM330X_SELECT_COMM_CMD) < 0) {
103 LOG_ERR("Failed to switch to I2C");
104 return -EIO;
105 }
106
107 return 0;
108 }
109
110 #define HM330X_DEFINE(inst) \
111 static struct hm330x_data hm330x_data_##inst; \
112 \
113 static const struct hm330x_config hm330x_config##inst = { \
114 .i2c = I2C_DT_SPEC_INST_GET(inst) \
115 }; \
116 \
117 SENSOR_DEVICE_DT_INST_DEFINE(inst, hm330x_init, NULL, &hm330x_data_##inst, \
118 &hm330x_config##inst, POST_KERNEL, \
119 CONFIG_SENSOR_INIT_PRIORITY, &hm330x_driver_api); \
120
121 DT_INST_FOREACH_STATUS_OKAY(HM330X_DEFINE)
122
