drivers/sensor: Add basic TI HDC20XX support

Add basic support for TI HDC20XX series (e.g. HDC2010, HDC2021, HDC2022,
HDC2080). It is able to get temperature and humidity in the default
14-bit resolution. Triggers, resolution selection, interrupt line, auto
measurement mode are currently not supported.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

drivers/sensor/CMakeLists.txt

@@ -27,6 +27,7 @@ add_subdirectory_ifdef(CONFIG_FXAS21002		fxas21002)
 add_subdirectory_ifdef(CONFIG_FXOS8700		fxos8700)
 add_subdirectory(grove)
 add_subdirectory_ifdef(CONFIG_TI_HDC		ti_hdc)
+add_subdirectory_ifdef(CONFIG_TI_HDC20XX	ti_hdc20xx)
 add_subdirectory_ifdef(CONFIG_HMC5883L		hmc5883l)
 add_subdirectory_ifdef(CONFIG_HP206C		hp206c)
 add_subdirectory_ifdef(CONFIG_HTS221		hts221)

drivers/sensor/Kconfig

@@ -92,6 +92,8 @@ source "drivers/sensor/grove/Kconfig"
 
 source "drivers/sensor/ti_hdc/Kconfig"
 
+source "drivers/sensor/ti_hdc20xx/Kconfig"
+
 source "drivers/sensor/hmc5883l/Kconfig"
 
 source "drivers/sensor/hp206c/Kconfig"

drivers/sensor/ti_hdc20xx/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(ti_hdc20xx.c)

drivers/sensor/ti_hdc20xx/Kconfig

@@ -0,0 +1,11 @@
+# TI_HDC20XX temperature and humidity sensor configuration options
+
+# Copyright (c) 2021 Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+config TI_HDC20XX
+	bool "Texas Instruments HDC20XX Temperature and Humidity Sensor"
+	depends on I2C
+	help
+	  Enable driver for TI HDC20XX temperature and humidity sensors
+	  (e.g. HDC2010, HDC2021, HDC2022, HDC2080).

drivers/sensor/ti_hdc20xx/ti_hdc20xx.c

@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2021 Aurelien Jarno
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <drivers/i2c.h>
+#include <drivers/sensor.h>
+#include <sys/byteorder.h>
+#include <sys/__assert.h>
+#include <logging/log.h>
+
+LOG_MODULE_REGISTER(TI_HDC20XX, CONFIG_SENSOR_LOG_LEVEL);
+
+/* Register addresses */
+#define TI_HDC20XX_REG_TEMP		0x00
+#define TI_HDC20XX_REG_HUMIDITY		0x02
+#define TI_HDC20XX_REG_MEAS_CFG		0x0F
+#define TI_HDC20XX_REG_MANUFACTURER_ID	0xFC
+#define TI_HDC20XX_REG_DEVICE_ID	0xFE
+
+/* Register values */
+#define TI_HDC20XX_MANUFACTURER_ID	0x5449
+#define TI_HDC20XX_DEVICE_ID		0x07D0
+
+/* Conversion time for 14-bit resolution. Temperature needs 660us and humidity 610us */
+#define TI_HDC20XX_CONVERSION_TIME      K_MSEC(2)
+
+/* Temperature and humidity scale and factors from the datasheet ("Register Maps" section) */
+#define TI_HDC20XX_RH_SCALE		100U
+#define TI_HDC20XX_TEMP_OFFSET		-40U
+#define TI_HDC20XX_TEMP_SCALE		165U
+
+struct ti_hdc20xx_config {
+	const struct device *bus;
+	uint16_t i2c_addr;
+};
+
+struct ti_hdc20xx_data {
+	int32_t t_sample;
+	int32_t rh_sample;
+};
+
+static int ti_hdc20xx_sample_fetch(const struct device *dev,
+				   enum sensor_channel chan)
+{
+	const struct ti_hdc20xx_config *config = dev->config;
+	struct ti_hdc20xx_data *data = dev->data;
+	uint16_t buf[2];
+	int rc;
+
+	__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
+
+	/* start conversion of both temperature and humidity with the default accuracy (14 bits) */
+	rc = i2c_reg_write_byte(config->bus, config->i2c_addr, TI_HDC20XX_REG_MEAS_CFG, 0x01);
+	if (rc < 0) {
+		LOG_ERR("Failed to write measurement configuration register");
+		return rc;
+	}
+
+	/* wait for the conversion to finish */
+	k_sleep(TI_HDC20XX_CONVERSION_TIME);
+
+	/* temperature and humidity registers are consecutive, read them in the same burst */
+	rc = i2c_burst_read(config->bus, config->i2c_addr,
+			    TI_HDC20XX_REG_TEMP, (uint8_t *)buf, sizeof(buf));
+	if (rc < 0) {
+		LOG_ERR("Failed to read sample data");
+		return rc;
+	}
+
+	data->t_sample = sys_le16_to_cpu(buf[0]);
+	data->rh_sample = sys_le16_to_cpu(buf[1]);
+
+	return 0;
+}
+
+
+static int ti_hdc20xx_channel_get(const struct device *dev,
+				  enum sensor_channel chan,
+				  struct sensor_value *val)
+{
+	struct ti_hdc20xx_data *data = dev->data;
+	int32_t tmp;
+
+	/* See datasheet "Register Maps" section for more details on processing sample data. */
+	switch (chan) {
+	case SENSOR_CHAN_AMBIENT_TEMP:
+		/* val = -40 + 165 * sample / 2^16 */
+		tmp = data->t_sample * TI_HDC20XX_TEMP_SCALE;
+		val->val1 = TI_HDC20XX_TEMP_OFFSET + (tmp >> 16);
+		/* x * 1000000 / 2^16 = x * 15625 / 2^10 */
+		val->val2 = ((tmp & 0xFFFF) * 15625U) >> 10;
+		break;
+	case SENSOR_CHAN_HUMIDITY:
+		/* val = 100 * sample / 2^16 */
+		tmp = data->rh_sample * TI_HDC20XX_RH_SCALE;
+		val->val1 = tmp >> 16;
+		/* x * 1000000 / 2^16 = x * 15625 / 2^10 */
+		val->val2 = ((tmp & 0xFFFF) * 15625U) >> 10;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct sensor_driver_api ti_hdc20xx_api_funcs = {
+	.sample_fetch = ti_hdc20xx_sample_fetch,
+	.channel_get = ti_hdc20xx_channel_get,
+};
+
+static int ti_hdc20xx_init(const struct device *dev)
+{
+	const struct ti_hdc20xx_config *config = dev->config;
+	uint16_t buf[2];
+	int rc;
+
+	if (!device_is_ready(config->bus)) {
+		LOG_ERR("I2C bus %s not ready", config->bus->name);
+		return -ENODEV;
+	}
+
+	/* manufacturer and device ID registers are consecutive, read them in the same burst */
+	rc = i2c_burst_read(config->bus, config->i2c_addr,
+			    TI_HDC20XX_REG_MANUFACTURER_ID, (uint8_t *)buf, sizeof(buf));
+	if (rc < 0) {
+		LOG_ERR("Failed to read manufacturer and device IDs");
+		return rc;
+	}
+
+	if (sys_le16_to_cpu(buf[0]) != TI_HDC20XX_MANUFACTURER_ID) {
+		LOG_ERR("Failed to get correct manufacturer ID");
+		return -EINVAL;
+	}
+	if (sys_le16_to_cpu(buf[1]) != TI_HDC20XX_DEVICE_ID) {
+		LOG_ERR("Unsupported device ID");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Main instantiation macro */
+#define TI_HDC20XX_DEFINE(inst, compat)							\
+	static struct ti_hdc20xx_data ti_hdc20xx_data_##compat##inst;			\
+	static const struct ti_hdc20xx_config ti_hdc20xx_config_##compat##inst = {	\
+		.bus = DEVICE_DT_GET(DT_BUS(DT_INST(inst, compat))),			\
+		.i2c_addr = DT_REG_ADDR(DT_INST(inst, compat))				\
+	};										\
+	DEVICE_DT_DEFINE(DT_INST(inst, compat),						\
+			ti_hdc20xx_init,						\
+			NULL,								\
+			&ti_hdc20xx_data_##compat##inst,				\
+			&ti_hdc20xx_config_##compat##inst,				\
+			POST_KERNEL,							\
+			CONFIG_SENSOR_INIT_PRIORITY,					\
+			&ti_hdc20xx_api_funcs);
+
+/* Create the struct device for every status "okay" node in the devicetree. */
+#define TI_HDC20XX_FOREACH_STATUS_OKAY(compat, fn)	\
+	COND_CODE_1(DT_HAS_COMPAT_STATUS_OKAY(compat),	\
+		    (UTIL_CAT(DT_FOREACH_OKAY_INST_,	\
+			      compat)(fn)),		\
+		    ())
+
+/*
+ * HDC2010 Low-Power Humidity and Temperature Digital Sensors
+ */
+#define TI_HDC2010_DEFINE(inst) TI_HDC20XX_DEFINE(inst, ti_hdc2010)
+TI_HDC20XX_FOREACH_STATUS_OKAY(ti_hdc2010, TI_HDC2010_DEFINE)
+
+/*
+ * HDC2021 High-Accuracy, Low-Power Humidity and Temperature Sensor
+ * With Assembly Protection Cover
+ */
+#define TI_HDC2021_DEFINE(inst) TI_HDC20XX_DEFINE(inst, ti_hdc2021)
+TI_HDC20XX_FOREACH_STATUS_OKAY(ti_hdc2021, TI_HDC2021_DEFINE)
+
+/*
+ * HDC2022 High-Accuracy, Low-Power Humidity and Temperature Sensor
+ * With IP67 Rated Water and Dust Protection Cover
+ */
+#define TI_HDC2022_DEFINE(inst) TI_HDC20XX_DEFINE(inst, ti_hdc2022)
+TI_HDC20XX_FOREACH_STATUS_OKAY(ti_hdc2022, TI_HDC2022_DEFINE)
+
+/*
+ * HDC2080 Low-Power Humidity and Temperature Digital Sensor
+ */
+#define TI_HDC2080_DEFINE(inst) TI_HDC20XX_DEFINE(inst, ti_hdc2080)
+TI_HDC20XX_FOREACH_STATUS_OKAY(ti_hdc2080, TI_HDC2080_DEFINE)

dts/bindings/sensor/ti,hdc2010.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+description: Texas Instruments HDC2010 Temperature and Humidity Sensor
+
+compatible: "ti,hdc2010"
+
+include: ti,hdc20xx.yaml

dts/bindings/sensor/ti,hdc2021.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+description: Texas Instruments HDC2021 Temperature and Humidity Sensor
+
+compatible: "ti,hdc2021"
+
+include: ti,hdc20xx.yaml

dts/bindings/sensor/ti,hdc2022.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+description: Texas Instruments HDC2022 Temperature and Humidity Sensor
+
+compatible: "ti,hdc2022"
+
+include: ti,hdc20xx.yaml

dts/bindings/sensor/ti,hdc2080.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+description: Texas Instruments HDC2080 Temperature and Humidity Sensor
+
+compatible: "ti,hdc2080"
+
+include: ti,hdc20xx.yaml

dts/bindings/sensor/ti,hdc20xx.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2021, Aurelien Jarno
+# SPDX-License-Identifier: Apache-2.0
+
+description: Texas Instruments HDC20XX Temperature and Humidity Sensor
+
+compatible: "ti,hdc20xx"
+
+include: i2c-device.yaml