eb0050f7c9
Adds driver for Everlight ALS-PT19 Ambient Light Sensor. Signed-off-by: Dipak Shetty <shetty.dipak@gmx.com>
132 lines
3.6 KiB
C
132 lines
3.6 KiB
C
/*
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* Copyright (c) 2025 Dipak Shetty <shetty.dipak@gmx.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT everlight_als_pt19
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#include <zephyr/device.h>
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#include <zephyr/devicetree.h>
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#include <zephyr/drivers/adc.h>
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#include <zephyr/drivers/sensor.h>
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#include <zephyr/kernel.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(ALS_PT19, CONFIG_SENSOR_LOG_LEVEL);
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struct als_pt19_data {
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struct adc_sequence sequence;
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uint16_t raw;
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};
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struct als_pt19_config {
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struct adc_dt_spec adc;
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uint32_t load_resistor;
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};
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static int als_pt19_sample_fetch(const struct device *dev, enum sensor_channel chan)
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{
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const struct als_pt19_config *config = dev->config;
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struct als_pt19_data *data = dev->data;
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int ret;
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if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_LIGHT) {
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LOG_ERR("Unsupported sensor channel");
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return -ENOTSUP;
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}
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ret = adc_read_dt(&config->adc, &data->sequence);
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if (ret != 0) {
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LOG_ERR("adc_read: %d", ret);
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}
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return ret;
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}
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static int als_pt19_channel_get(const struct device *dev, enum sensor_channel chan,
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struct sensor_value *val)
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{
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const struct als_pt19_config *config = dev->config;
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struct als_pt19_data *data = dev->data;
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int32_t raw_val = data->raw;
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int ret;
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__ASSERT_NO_MSG(val != NULL);
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if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_LIGHT) {
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LOG_ERR("Unsupported sensor channel");
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return -ENOTSUP;
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}
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ret = adc_raw_to_millivolts_dt(&config->adc, &raw_val);
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if (ret != 0) {
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LOG_ERR("to_mv: %d", ret);
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return ret;
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}
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LOG_DBG("Raw voltage: %d mV", raw_val);
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/* Calculate current through the load resistor (in microamps) */
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const int32_t current_ua = (raw_val * 1000) / config->load_resistor;
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/* Convert current to Lux (200µA = 1000 Lux) */
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const int32_t lux = (current_ua * 1000) / 200;
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/* Convert to sensor_value format */
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val->val1 = lux;
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val->val2 = 0;
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LOG_DBG("ADC: %d/%dmV, Current: %duA, Lux: %d", raw_val, config->adc.vref_mv, current_ua,
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val->val1);
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return 0;
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}
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static DEVICE_API(sensor, als_pt19_driver_api) = {
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.sample_fetch = als_pt19_sample_fetch,
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.channel_get = als_pt19_channel_get,
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};
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static int als_pt19_init(const struct device *dev)
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{
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const struct als_pt19_config *config = dev->config;
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struct als_pt19_data *data = dev->data;
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int ret;
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if (!adc_is_ready_dt(&config->adc)) {
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LOG_ERR("ADC is not ready");
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return -ENODEV;
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}
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ret = adc_channel_setup_dt(&config->adc);
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if (ret != 0) {
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LOG_ERR("ADC channel setup: %d", ret);
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return ret;
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}
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ret = adc_sequence_init_dt(&config->adc, &data->sequence);
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if (ret != 0) {
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LOG_ERR("ADC sequence: %d", ret);
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return ret;
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}
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data->sequence.buffer = &data->raw;
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data->sequence.buffer_size = sizeof(data->raw);
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return 0;
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}
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#define ALS_PT19_INST(inst) \
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static struct als_pt19_data als_pt19_data_##inst; \
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\
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static const struct als_pt19_config als_pt19_cfg_##inst = { \
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.adc = ADC_DT_SPEC_INST_GET(inst), \
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.load_resistor = DT_INST_PROP(inst, load_resistor)}; \
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\
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SENSOR_DEVICE_DT_INST_DEFINE(inst, &als_pt19_init, NULL, &als_pt19_data_##inst, \
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&als_pt19_cfg_##inst, POST_KERNEL, \
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CONFIG_SENSOR_INIT_PRIORITY, &als_pt19_driver_api);
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DT_INST_FOREACH_STATUS_OKAY(ALS_PT19_INST)
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