| /* |
| * Copyright (c) 2023 TOKITA Hiroshi |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <zephyr/device.h> |
| #include <zephyr/devicetree.h> |
| #include <zephyr/drivers/sensor.h> |
| #include <zephyr/drivers/adc.h> |
| #include <zephyr/logging/log.h> |
| |
| #include <hardware/adc.h> |
| |
| LOG_MODULE_REGISTER(rpi_pico_temp, CONFIG_SENSOR_LOG_LEVEL); |
| |
| #define DT_DRV_COMPAT raspberrypi_pico_temp |
| |
| struct rpi_pico_temp_config { |
| const struct device *adc; |
| const struct adc_channel_cfg ch_cfg; |
| const int32_t vbe; |
| const int32_t vbe_slope; |
| }; |
| |
| struct rpi_pico_temp_data { |
| struct adc_sequence adc_seq; |
| int16_t sample; |
| }; |
| |
| static int rpi_pico_temp_sample_fetch(const struct device *dev, enum sensor_channel chan) |
| { |
| const struct rpi_pico_temp_config *cfg = dev->config; |
| struct rpi_pico_temp_data *data = dev->data; |
| int rc; |
| |
| if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_DIE_TEMP) { |
| return -ENOTSUP; |
| } |
| |
| rc = adc_channel_setup(cfg->adc, &cfg->ch_cfg); |
| if (rc) { |
| LOG_DBG("Setup ADC channel %u failed with %d", cfg->ch_cfg.channel_id, rc); |
| return rc; |
| } |
| |
| rc = adc_read(cfg->adc, &data->adc_seq); |
| |
| return rc; |
| } |
| |
| static int rpi_pico_temp_channel_get(const struct device *dev, enum sensor_channel chan, |
| struct sensor_value *val) |
| { |
| const struct rpi_pico_temp_config *cfg = dev->config; |
| struct rpi_pico_temp_data *data = dev->data; |
| int32_t mv = 0; |
| int32_t work; |
| int rc; |
| |
| if (chan != SENSOR_CHAN_DIE_TEMP) { |
| return -ENOTSUP; |
| } |
| |
| mv = data->sample; |
| rc = adc_raw_to_millivolts(adc_ref_internal(cfg->adc), cfg->ch_cfg.gain, |
| data->adc_seq.resolution, &mv); |
| if (rc) { |
| LOG_DBG("adc_raw_to_millivolts() failed %d", rc); |
| return rc; |
| } |
| |
| /* |
| * Calculate CPU temperature from voltage by the equation: |
| * T = 27 - (ADC_Voltage - 0.706)/0.001721 |
| */ |
| work = ((27 * (-cfg->vbe_slope)) - (mv * 1000 - cfg->vbe)); |
| val->val1 = work / (-cfg->vbe_slope); |
| work -= val->val1 * (-cfg->vbe_slope); |
| val->val2 = work * 1000000 / (-cfg->vbe_slope); |
| |
| return 0; |
| } |
| |
| static const struct sensor_driver_api rpi_pico_temp_driver_api = { |
| .sample_fetch = rpi_pico_temp_sample_fetch, |
| .channel_get = rpi_pico_temp_channel_get, |
| }; |
| |
| static int rpi_pico_temp_init(const struct device *dev) |
| { |
| const struct rpi_pico_temp_config *cfg = dev->config; |
| |
| if (!device_is_ready(cfg->adc)) { |
| LOG_ERR("Device %s is not ready", cfg->adc->name); |
| return -ENODEV; |
| } |
| |
| adc_set_temp_sensor_enabled(true); |
| |
| return 0; |
| } |
| |
| #define RPI_PICO_TEMP_DEFINE(inst) \ |
| static const struct rpi_pico_temp_config rpi_pico_temp_config_##inst = { \ |
| .adc = DEVICE_DT_GET(DT_INST_IO_CHANNELS_CTLR(inst)), \ |
| .vbe = DT_INST_PROP(inst, vbe), \ |
| .vbe_slope = DT_INST_PROP(inst, vbe_slope), \ |
| .ch_cfg = \ |
| { \ |
| .gain = ADC_GAIN_1, \ |
| .reference = ADC_REF_INTERNAL, \ |
| .acquisition_time = ADC_ACQ_TIME_DEFAULT, \ |
| .channel_id = DT_INST_IO_CHANNELS_INPUT(inst), \ |
| .differential = 0, \ |
| }, \ |
| }; \ |
| static struct rpi_pico_temp_data rpi_pico_temp_dev_data_##inst = { \ |
| .adc_seq = \ |
| { \ |
| .channels = BIT(DT_INST_IO_CHANNELS_INPUT(inst)), \ |
| .buffer = &rpi_pico_temp_dev_data_##inst.sample, \ |
| .buffer_size = sizeof(rpi_pico_temp_dev_data_##inst.sample), \ |
| .resolution = 12U, \ |
| }, \ |
| }; \ |
| \ |
| SENSOR_DEVICE_DT_INST_DEFINE(inst, rpi_pico_temp_init, NULL, \ |
| &rpi_pico_temp_dev_data_##inst, &rpi_pico_temp_config_##inst, \ |
| POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, \ |
| &rpi_pico_temp_driver_api); |
| |
| DT_INST_FOREACH_STATUS_OKAY(RPI_PICO_TEMP_DEFINE) |