drivers: sensor: hs300x: Add driver for Renesas HS300x sensors

Adds support for Renesas HS3001 and HS3003 temperature/humidity sensors
connected via an I2C bus.

Signed-off-by: Ian Morris <ian.d.morris@outlook.com>

drivers/sensor/CMakeLists.txt

@@ -47,6 +47,7 @@ add_subdirectory_ifdef(CONFIG_HAS_STMEMSC stmemsc)
 add_subdirectory_ifdef(CONFIG_HM330X hm330x)
 add_subdirectory_ifdef(CONFIG_HMC5883L hmc5883l)
 add_subdirectory_ifdef(CONFIG_HP206C hp206c)
+add_subdirectory_ifdef(CONFIG_HS300X hs300x)
 add_subdirectory_ifdef(CONFIG_HTS221 hts221)
 add_subdirectory_ifdef(CONFIG_I3G4250D i3g4250d)
 add_subdirectory_ifdef(CONFIG_ICM42605 icm42605)

drivers/sensor/Kconfig

@@ -119,6 +119,7 @@ source "drivers/sensor/grow_r502a/Kconfig"
 source "drivers/sensor/hm330x/Kconfig"
 source "drivers/sensor/hmc5883l/Kconfig"
 source "drivers/sensor/hp206c/Kconfig"
+source "drivers/sensor/hs300x/Kconfig"
 source "drivers/sensor/hts221/Kconfig"
 source "drivers/sensor/i3g4250d/Kconfig"
 source "drivers/sensor/icm42605/Kconfig"

drivers/sensor/hs300x/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(hs300x.c)

drivers/sensor/hs300x/Kconfig

@@ -0,0 +1,12 @@
+# Renesas HS300x temperature and humidity sensor configuration options
+
+# Copyright (c) 2023 Ian Morris
+# SPDX-License-Identifier: Apache-2.0
+
+config HS300X
+	bool "HS300x Temperature and Humidity Sensor"
+	default y
+	depends on DT_HAS_RENESAS_HS300X_ENABLED
+	select I2C
+	help
+	  Enable driver for HS300x temperature and humidity sensors.

drivers/sensor/hs300x/hs300x.c

@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2023 Ian Morris
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT renesas_hs300x
+
+#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>
+
+#define HS300X_STATUS_MASK (BIT(0) | BIT(1))
+
+LOG_MODULE_REGISTER(HS300X, CONFIG_SENSOR_LOG_LEVEL);
+
+struct hs300x_config {
+	struct i2c_dt_spec bus;
+};
+
+struct hs300x_data {
+	int16_t t_sample;
+	uint16_t rh_sample;
+};
+
+static int hs300x_read_sample(const struct device *dev, uint16_t *t_sample, uint16_t *rh_sample)
+{
+	const struct hs300x_config *cfg = dev->config;
+	uint8_t rx_buf[4];
+	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;
+	}
+
+	if ((rx_buf[3] & HS300X_STATUS_MASK) != 0) {
+		LOG_ERR("Stale data");
+		return -EIO;
+	}
+
+	*rh_sample = sys_get_be16(rx_buf);
+	*t_sample = sys_get_be16(&rx_buf[2]);
+
+	/* Remove status bits (only present in temperature value)*/
+	*t_sample >>= 2;
+
+	return 0;
+}
+
+static int hs300x_sample_fetch(const struct device *dev, enum sensor_channel chan)
+{
+	struct hs300x_data *data = dev->data;
+	const struct hs300x_config *cfg = dev->config;
+	int rc;
+
+	if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_AMBIENT_TEMP &&
+	    chan != SENSOR_CHAN_HUMIDITY) {
+		return -ENOTSUP;
+	}
+
+	/*
+	 * Initiate a measurement simply by sending 7-bit address followed
+	 * by an eighth bit set to 0 (write) and NO data.
+	 */
+	rc = i2c_write_dt(&cfg->bus, NULL, 0);
+	if (rc < 0) {
+		LOG_ERR("Failed to start 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 = hs300x_read_sample(dev, &data->t_sample, &data->rh_sample);
+	if (rc < 0) {
+		LOG_ERR("Failed to fetch data.");
+		return rc;
+	}
+
+	return 0;
+}
+
+static void hs300x_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 hs300x_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 hs300x_channel_get(const struct device *dev, enum sensor_channel chan,
+			      struct sensor_value *val)
+{
+	const struct hs300x_data *data = dev->data;
+
+	if (chan == SENSOR_CHAN_AMBIENT_TEMP) {
+		hs300x_temp_convert(val, data->t_sample);
+	} else if (chan == SENSOR_CHAN_HUMIDITY) {
+		hs300x_rh_convert(val, data->rh_sample);
+	} else {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+static int hs300x_init(const struct device *dev)
+{
+	const struct hs300x_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 const struct sensor_driver_api hs300x_driver_api = {.sample_fetch = hs300x_sample_fetch,
+							   .channel_get = hs300x_channel_get};
+
+#define DEFINE_HS300X(n)                                                                           \
+	static struct hs300x_data hs300x_data_##n;                                                 \
+                                                                                                   \
+	static const struct hs300x_config hs300x_config_##n = {.bus = I2C_DT_SPEC_INST_GET(n)};    \
+                                                                                                   \
+	SENSOR_DEVICE_DT_INST_DEFINE(n, hs300x_init, NULL, &hs300x_data_##n, &hs300x_config_##n,   \
+				     POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,                     \
+				     &hs300x_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(DEFINE_HS300X)

dts/bindings/sensor/renesas,hs300x.yaml

@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2023 Ian Morris
+#
+# SPDX-License-Identifier: Apache-2.0
+
+description: Renesas HS300x humidity and temperature sensor
+
+compatible: "renesas,hs300x"
+
+include: [sensor-device.yaml, i2c-device.yaml]

tests/drivers/build_all/sensor/i2c.dtsi

@@ -807,3 +807,8 @@ test_i2c_lps22df: lps22df@79 {
 	drdy-gpios = <&test_gpio 0 0>;
 	status = "okay";
 };
+
+test_i2c_hs300x: hs300x@79 {
+	compatible = "renesas,hs300x";
+	reg = <0x79>;
+};