drivers: sensor: current_amp: add driver

Add current sense amplifier driver.

Implements https://github.com/zephyrproject-rtos/zephyr/issues/60415

Co-authored-by: Marco Argiolas <marco.argiolas@ftpsolutions.com.au>

Signed-off-by: Nick Ward <nix.ward@gmail.com>

drivers/sensor/CMakeLists.txt

@@ -27,6 +27,7 @@ add_subdirectory_ifdef(CONFIG_BMM150 bmm150)
 add_subdirectory_ifdef(CONFIG_BMP388 bmp388)
 add_subdirectory_ifdef(CONFIG_BQ274XX bq274xx)
 add_subdirectory_ifdef(CONFIG_CCS811 ccs811)
+add_subdirectory_ifdef(CONFIG_CURRENT_AMP current_amp)
 add_subdirectory_ifdef(CONFIG_DHT dht)
 add_subdirectory_ifdef(CONFIG_DPS310 dps310)
 add_subdirectory_ifdef(CONFIG_DS18B20 ds18b20)

drivers/sensor/Kconfig

@@ -83,6 +83,7 @@ source "drivers/sensor/bmm150/Kconfig"
 source "drivers/sensor/bmp388/Kconfig"
 source "drivers/sensor/bq274xx/Kconfig"
 source "drivers/sensor/ccs811/Kconfig"
+source "drivers/sensor/current_amp/Kconfig"
 source "drivers/sensor/dht/Kconfig"
 source "drivers/sensor/dps310/Kconfig"
 source "drivers/sensor/ds18b20/Kconfig"

drivers/sensor/current_amp/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(current_amp.c)

drivers/sensor/current_amp/Kconfig

@@ -0,0 +1,13 @@
+# Current sense amplifier driver
+#
+# Copyright (c) 2023 FTP Technologies
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config CURRENT_AMP
+	bool "Current sense amplifier driver"
+	default y
+	depends on DT_HAS_CURRENT_SENSE_AMPLIFIER_ENABLED
+	depends on ADC
+	help
+	  Enable current sense amplifier driver.

drivers/sensor/current_amp/current_amp.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2023 FTP Technologies
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT current_sense_amplifier
+
+#include <zephyr/drivers/adc.h>
+#include <zephyr/drivers/adc/current_sense_amplifier.h>
+#include <zephyr/drivers/sensor.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(current_amp, CONFIG_SENSOR_LOG_LEVEL);
+
+struct current_sense_amplifier_data {
+	struct adc_sequence sequence;
+	int16_t raw;
+};
+
+static int fetch(const struct device *dev, enum sensor_channel chan)
+{
+	const struct current_sense_amplifier_dt_spec *config = dev->config;
+	struct current_sense_amplifier_data *data = dev->data;
+	int ret;
+
+	if ((chan != SENSOR_CHAN_CURRENT) && (chan != SENSOR_CHAN_ALL)) {
+		return -ENOTSUP;
+	}
+
+	ret = adc_read(config->port.dev, &data->sequence);
+	if (ret != 0) {
+		LOG_ERR("adc_read: %d", ret);
+	}
+
+	return ret;
+}
+
+static int get(const struct device *dev, enum sensor_channel chan, struct sensor_value *val)
+{
+	const struct current_sense_amplifier_dt_spec *config = dev->config;
+	struct current_sense_amplifier_data *data = dev->data;
+	int32_t raw_val = data->raw;
+	int32_t i_ma;
+	int ret;
+
+	__ASSERT_NO_MSG(val != NULL);
+
+	if (chan != SENSOR_CHAN_CURRENT) {
+		return -ENOTSUP;
+	}
+
+	ret = adc_raw_to_millivolts_dt(&config->port, &raw_val);
+	if (ret != 0) {
+		LOG_ERR("raw_to_mv: %d", ret);
+		return ret;
+	}
+
+	i_ma = raw_val;
+	current_sense_amplifier_scale_dt(config, &i_ma);
+
+	LOG_DBG("%d/%d, %dmV, current:%duA", data->raw,
+		(1 << data->sequence.resolution) - 1, raw_val, i_ma);
+
+	val->val1 = i_ma / 1000;
+	val->val2 = i_ma % 1000;
+
+	return 0;
+}
+
+static const struct sensor_driver_api current_api = {
+	.sample_fetch = fetch,
+	.channel_get = get,
+};
+
+static int current_init(const struct device *dev)
+{
+	const struct current_sense_amplifier_dt_spec *config = dev->config;
+	struct current_sense_amplifier_data *data = dev->data;
+	int ret;
+
+	if (!adc_is_ready_dt(&config->port)) {
+		LOG_ERR("ADC is not ready");
+		return -ENODEV;
+	}
+
+	ret = adc_channel_setup_dt(&config->port);
+	if (ret != 0) {
+		LOG_ERR("setup: %d", ret);
+		return ret;
+	}
+
+	ret = adc_sequence_init_dt(&config->port, &data->sequence);
+	if (ret != 0) {
+		LOG_ERR("sequence init: %d", ret);
+		return ret;
+	}
+
+	data->sequence.buffer = &data->raw;
+	data->sequence.buffer_size = sizeof(data->raw);
+
+	return 0;
+}
+
+#define CURRENT_SENSE_AMPLIFIER_INIT(inst)                                                         \
+	static struct current_sense_amplifier_data current_amp_##inst##_data;                      \
+                                                                                                   \
+	static const struct current_sense_amplifier_dt_spec current_amp_##inst##_config =          \
+		CURRENT_SENSE_AMPLIFIER_DT_SPEC_GET(DT_DRV_INST(inst));                            \
+                                                                                                   \
+	SENSOR_DEVICE_DT_INST_DEFINE(inst, &current_init, NULL, &current_amp_##inst##_data,        \
+			      &current_amp_##inst##_config, POST_KERNEL,                           \
+			      CONFIG_SENSOR_INIT_PRIORITY, &current_api);
+
+DT_INST_FOREACH_STATUS_OKAY(CURRENT_SENSE_AMPLIFIER_INIT)