drivers: sensor: Add HS400x driver

Adds Renesas HS400x temperature and humidity sensors driver.
Signed-off-by: Mariëlle Korthout <marielle.korthout.jc@renesas.com>

drivers/sensor/renesas/CMakeLists.txt

@@ -3,5 +3,6 @@
 
 # zephyr-keep-sorted-start
 add_subdirectory_ifdef(CONFIG_HS300X hs300x)
+add_subdirectory_ifdef(CONFIG_HS400X hs400x)
 add_subdirectory_ifdef(CONFIG_ISL29035 isl29035)
 # zephyr-keep-sorted-stop

drivers/sensor/renesas/Kconfig

@@ -3,5 +3,6 @@
 
 # zephyr-keep-sorted-start
 source "drivers/sensor/renesas/hs300x/Kconfig"
+source "drivers/sensor/renesas/hs400x/Kconfig"
 source "drivers/sensor/renesas/isl29035/Kconfig"
 # zephyr-keep-sorted-stop

drivers/sensor/renesas/hs400x/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(hs400x.c)

drivers/sensor/renesas/hs400x/Kconfig

@@ -0,0 +1,21 @@
+# HS400X temperature and humidity sensor
+
+# Copyright (c) 2024 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+config HS400X
+	bool "HS400x sensor"
+	default y
+	depends on DT_HAS_RENESAS_HS400X_ENABLED
+	help
+	  Enable driver for HS400x temperature and humidity sensors.
+
+if HS400X
+
+config HS400X_CRC
+	bool "HS400X CRC check"
+	select CRC
+	help
+	 Verify the checksum byte from measurements
+
+endif # HS400x

drivers/sensor/renesas/hs400x/hs400x.c

@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2024 Renesas Electronics Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT renesas_hs400x
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/sys/__assert.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/crc.h>
+
+#define CRC_POLYNOMIAL 0x1D
+#define CRC_INITIAL 0xFF
+
+LOG_MODULE_REGISTER(HS400X, CONFIG_SENSOR_LOG_LEVEL);
+
+struct hs400x_config {
+	struct i2c_dt_spec bus;
+};
+
+struct hs400x_data {
+	int16_t t_sample;
+	uint16_t rh_sample;
+};
+
+static int hs400x_read_sample(const struct device *dev, uint16_t *t_sample, uint16_t *rh_sample)
+{
+	const struct hs400x_config *cfg = dev->config;
+	uint8_t rx_buf[5];
+	int rc;
+
+	rc = i2c_read_dt(&cfg->bus, rx_buf, sizeof(rx_buf));
+	if (rc < 0) {
+		LOG_ERR("Failed to read data from device.");
+		return rc;
+	}
+
+	*rh_sample = sys_get_be16(rx_buf);
+	*t_sample = sys_get_be16(&rx_buf[2]);
+
+	/*
+	 * The sensor sends a checkum after each measurement. See datasheet "CRC Checksum
+	 * Calculation" section for more details on checking the checksum.
+	 */
+#if CONFIG_HS400X_CRC
+	uint8_t crc = crc8(rx_buf, 4, CRC_POLYNOMIAL, CRC_INITIAL, 0);
+
+	if (crc != rx_buf[4]) {
+		LOG_ERR("CRC check failed: computed=%u,expected=%u", crc, rx_buf[4]);
+		return -EIO;
+	}
+#endif
+
+	return 0;
+}
+
+static int hs400x_sample_fetch(const struct device *dev, enum sensor_channel chan)
+{
+	struct hs400x_data *data = dev->data;
+	const struct hs400x_config *cfg = dev->config;
+	int rc;
+	uint8_t no_hold_measurement = 0xF5;
+
+	if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_AMBIENT_TEMP &&
+	    chan != SENSOR_CHAN_HUMIDITY) {
+		return -ENOTSUP;
+	}
+
+	rc = i2c_write_dt(&cfg->bus, (const uint8_t *)&no_hold_measurement, 1);
+	if (rc < 0) {
+		LOG_ERR("Failed to send measurement.");
+		return rc;
+	}
+
+	/*
+	 * According to datasheet maximum time to make temperature and humidity
+	 * measurements is 33ms, add a little safety margin...
+	 */
+	k_msleep(50);
+
+	rc = hs400x_read_sample(dev, &data->t_sample, &data->rh_sample);
+	if (rc < 0) {
+		LOG_ERR("Failed to fetch data.");
+		return rc;
+	}
+
+	return 0;
+}
+
+static void hs400x_temp_convert(struct sensor_value *val, int16_t raw)
+{
+	int32_t micro_c;
+
+	/*
+	 * Convert to micro Celsius. See datasheet "Calculating Humidity and
+	 * Temperature Output" section for more details on processing sample data.
+	 */
+	micro_c = (((int64_t)raw * 165000000) / 16383) - 40000000;
+
+	val->val1 = micro_c / 1000000;
+	val->val2 = micro_c % 1000000;
+}
+
+static void hs400x_rh_convert(struct sensor_value *val, uint16_t raw)
+{
+	int32_t micro_rh;
+
+	/*
+	 * Convert to micro %RH. See datasheet "Calculating Humidity and
+	 * Temperature Output" section for more details on processing sample data.
+	 */
+	micro_rh = ((uint64_t)raw * 100000000) / 16383;
+
+	val->val1 = micro_rh / 1000000;
+	val->val2 = micro_rh % 1000000;
+}
+
+static int hs400x_channel_get(const struct device *dev, enum sensor_channel chan,
+			      struct sensor_value *val)
+{
+	const struct hs400x_data *data = dev->data;
+
+	if (chan == SENSOR_CHAN_AMBIENT_TEMP) {
+		hs400x_temp_convert(val, data->t_sample);
+	} else if (chan == SENSOR_CHAN_HUMIDITY) {
+		hs400x_rh_convert(val, data->rh_sample);
+	} else {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+static int hs400x_init(const struct device *dev)
+{
+	const struct hs400x_config *cfg = dev->config;
+
+	if (!i2c_is_ready_dt(&cfg->bus)) {
+		LOG_ERR("I2C dev %s not ready", cfg->bus.bus->name);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static DEVICE_API(sensor, hs400x_driver_api) = {
+	.sample_fetch = hs400x_sample_fetch,
+	.channel_get = hs400x_channel_get,
+};
+
+#define DEFINE_HS400X(n)                                                                           \
+	static struct hs400x_data hs400x_data_##n;                                                 \
+                                                                                                   \
+	static const struct hs400x_config hs400x_config_##n = {.bus = I2C_DT_SPEC_INST_GET(n)};    \
+                                                                                                   \
+	SENSOR_DEVICE_DT_INST_DEFINE(n, hs400x_init, NULL, &hs400x_data_##n, &hs400x_config_##n,   \
+				     POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,                     \
+				     &hs400x_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(DEFINE_HS400X)

dts/bindings/sensor/renesas,hs400x.yaml

@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2024 Renesas Electronics Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+description: Renesas HS400x humidity and temperature sensor
+
+compatible: "renesas,hs400x"
+
+include: [sensor-device.yaml, i2c-device.yaml]