drivers: sensor: add a stm32 sensor driver for the internal VBat (32222e07) · Commits · Wenxi XU / zephyr

drivers/sensor/CMakeLists.txt

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		@@ -89,6 +89,7 @@ add_subdirectory_ifdef(CONFIG_SI7210 si7210)
		add_subdirectory_ifdef(CONFIG_SM351LT sm351lt)
		add_subdirectory_ifdef(CONFIG_HAS_STMEMSC stmemsc)
		add_subdirectory_ifdef(CONFIG_STM32_TEMP stm32_temp)
		add_subdirectory_ifdef(CONFIG_STM32_VBAT stm32_vbat)
		add_subdirectory_ifdef(CONFIG_STTS751 stts751)
		add_subdirectory_ifdef(CONFIG_SX9500 sx9500)
		add_subdirectory_ifdef(CONFIG_TH02 th02)

drivers/sensor/Kconfig

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		@@ -216,6 +216,8 @@ source "drivers/sensor/sm351lt/Kconfig"

		source "drivers/sensor/stm32_temp/Kconfig"

		source "drivers/sensor/stm32_vbat/Kconfig"

		source "drivers/sensor/stts751/Kconfig"

		source "drivers/sensor/sx9500/Kconfig"

drivers/sensor/stm32_vbat/CMakeLists.txt

0 → 100644

+5 −0

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		# SPDX-License-Identifier: Apache-2.0

		zephyr_library()

		zephyr_library_sources(stm32_vbat.c)

drivers/sensor/stm32_vbat/Kconfig

0 → 100644

+10 −0

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		# STM32 battery sensor configuration options

		# Copyright (c) 2022 STMicroelectronics
		# SPDX-License-Identifier: Apache-2.0

		config STM32_VBAT
		bool "STM32 Vbat Sensor"
		depends on ADC && (SOC_FAMILY_STM32 && !SOC_SERIES_STM32F1X)
		help
		Enable driver for STM32 Vbat sensor and then also ADC

drivers/sensor/stm32_vbat/stm32_vbat.c

0 → 100644

+128 −0

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		/*
		* Copyright (c) 2022 STMicroelectronics
		*
		* SPDX-License-Identifier: Apache-2.0
		*/

		#include <device.h>
		#include <drivers/sensor.h>
		#include <drivers/adc.h>
		#include <logging/log.h>

		LOG_MODULE_REGISTER(stm32_vbat, CONFIG_SENSOR_LOG_LEVEL);

		#if DT_HAS_COMPAT_STATUS_OKAY(st_stm32_vbat)
		#define DT_DRV_COMPAT st_stm32_vbat
		#else
		#error "No compatible devicetree node found"
		#endif

		struct stm32_vbat_data {
		const struct device *adc;
		const struct adc_channel_cfg adc_cfg;
		struct adc_sequence adc_seq;
		struct k_mutex mutex;
		int16_t sample_buffer;
		int16_t raw; /* raw adc Sensor value */
		};

		struct stm32_vbat_config {
		uint16_t vref_mv;
		int ratio;
		};

		static int stm32_vbat_sample_fetch(const struct device *dev, enum sensor_channel chan)
		{
		struct stm32_vbat_data *data = dev->data;
		struct adc_sequence *sp = &data->adc_seq;
		int rc;

		if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_VOLTAGE) {
		return -ENOTSUP;
		}

		k_mutex_lock(&data->mutex, K_FOREVER);

		rc = adc_channel_setup(data->adc, &data->adc_cfg);

		if (rc) {
		LOG_DBG("Setup AIN%u got %d", data->adc_cfg.channel_id, rc);
		goto unlock;
		}

		rc = adc_read(data->adc, sp);
		if (rc == 0) {
		data->raw = data->sample_buffer;
		}

		unlock:
		k_mutex_unlock(&data->mutex);

		return rc;
		}

		static int stm32_vbat_channel_get(const struct device *dev, enum sensor_channel chan,
		struct sensor_value *val)
		{
		struct stm32_vbat_data *data = dev->data;
		const struct stm32_vbat_config *cfg = dev->config;
		float voltage;

		if (chan != SENSOR_CHAN_VOLTAGE) {
		return -ENOTSUP;
		}

		voltage = data->raw * cfg->vref_mv / 0x0FFF; /* Sensor value in millivolts */
		/* considering the vbat input through a resistor bridge */
		voltage = voltage * cfg->ratio / 1000; /* value of SENSOR_CHAN_VOLTAGE in Volt */

		return sensor_value_from_double(val, voltage);
		}

		static const struct sensor_driver_api stm32_vbat_driver_api = {
		.sample_fetch = stm32_vbat_sample_fetch,
		.channel_get = stm32_vbat_channel_get,
		};

		static int stm32_vbat_init(const struct device *dev)
		{
		struct stm32_vbat_data *data = dev->data;
		struct adc_sequence *asp = &data->adc_seq;

		k_mutex_init(&data->mutex);

		if (!device_is_ready(data->adc)) {
		LOG_ERR("Device %s is not ready", data->adc->name);
		return -ENODEV;
		}

		*asp = (struct adc_sequence){
		.channels = BIT(data->adc_cfg.channel_id),
		.buffer = &data->sample_buffer,
		.buffer_size = sizeof(data->sample_buffer),
		.resolution = 12U,
		};

		return 0;
		}

		#define STM32_VBAT DT_PROP(DT_INST_IO_CHANNELS_CTLR(0), vref_mv)

		static struct stm32_vbat_config stm32_vbat_dev_config = {
		.vref_mv = DT_PROP(DT_INST_IO_CHANNELS_CTLR(0), vref_mv),
		.ratio = DT_INST_PROP(0, ratio),
		};

		static struct stm32_vbat_data stm32_vbat_dev_data = {
		.adc = DEVICE_DT_GET(DT_INST_IO_CHANNELS_CTLR(0)),
		.adc_cfg = {
		.gain = ADC_GAIN_1,
		.reference = ADC_REF_INTERNAL,
		.acquisition_time = ADC_ACQ_TIME_MAX,
		.channel_id = DT_INST_IO_CHANNELS_INPUT(0),
		.differential = 0,
		},
		};

		DEVICE_DT_INST_DEFINE(0, stm32_vbat_init, NULL, &stm32_vbat_dev_data, &stm32_vbat_dev_config,
		POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, &stm32_vbat_driver_api);

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