drivers: sensors: ti_hdc20xx: add support for DRDY/INT pin

Add optional support for the DRDY/INT pin. This avoids waiting a fixed
time for the temperature and humidity conversion to finish.

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

drivers/sensor/ti_hdc20xx/ti_hdc20xx.c

@@ -5,6 +5,7 @@
  */
 
 #include <kernel.h>
+#include <drivers/gpio.h>
 #include <drivers/i2c.h>
 #include <drivers/sensor.h>
 #include <sys/byteorder.h>
@@ -16,6 +17,7 @@ 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_INT_EN		0x07
 #define TI_HDC20XX_REG_CONFIG		0x0E
 #define TI_HDC20XX_REG_MEAS_CFG		0x0F
 #define TI_HDC20XX_REG_MANUFACTURER_ID	0xFC
@@ -26,7 +28,9 @@ LOG_MODULE_REGISTER(TI_HDC20XX, CONFIG_SENSOR_LOG_LEVEL);
 #define TI_HDC20XX_DEVICE_ID		0x07D0
 
 /* Register bits */
+#define TI_HDC20XX_BIT_INT_EN_DRDY_EN		0x80
 #define TI_HDC20XX_BIT_CONFIG_SOFT_RES		0x80
+#define TI_HDC20XX_BIT_CONFIG_DRDY_INT_EN	0x04
 
 /* Reset time: not in the datasheet, but found by trial and error */
 #define TI_HDC20XX_RESET_TIME		K_MSEC(1)
@@ -41,13 +45,27 @@ LOG_MODULE_REGISTER(TI_HDC20XX, CONFIG_SENSOR_LOG_LEVEL);
 
 struct ti_hdc20xx_config {
 	struct i2c_dt_spec bus;
+	struct gpio_dt_spec gpio_int;
 };
 
 struct ti_hdc20xx_data {
+	struct gpio_callback cb_int;
+	struct k_sem sem_int;
+
 	uint16_t t_sample;
 	uint16_t rh_sample;
 };
 
+static void ti_hdc20xx_int_callback(const struct device *dev,
+				    struct gpio_callback *cb, uint32_t pins)
+{
+	struct ti_hdc20xx_data *data = CONTAINER_OF(cb, struct ti_hdc20xx_data, cb_int);
+
+	ARG_UNUSED(pins);
+
+	k_sem_give(&data->sem_int);
+}
+
 static int ti_hdc20xx_sample_fetch(const struct device *dev,
 				   enum sensor_channel chan)
 {
@@ -66,7 +84,11 @@ static int ti_hdc20xx_sample_fetch(const struct device *dev,
 	}
 
 	/* wait for the conversion to finish */
+	if (config->gpio_int.port) {
+		k_sem_take(&data->sem_int, K_FOREVER);
+	} else {
 		k_sleep(TI_HDC20XX_CONVERSION_TIME);
+	}
 
 	/* temperature and humidity registers are consecutive, read them in the same burst */
 	rc = i2c_burst_read_dt(&config->bus, TI_HDC20XX_REG_TEMP, (uint8_t *)buf, sizeof(buf));
@@ -136,6 +158,7 @@ static int ti_hdc20xx_reset(const struct device *dev)
 static int ti_hdc20xx_init(const struct device *dev)
 {
 	const struct ti_hdc20xx_config *config = dev->config;
+	struct ti_hdc20xx_data *data = dev->data;
 	uint16_t buf[2];
 	int rc;
 
@@ -167,6 +190,54 @@ static int ti_hdc20xx_init(const struct device *dev)
 		return rc;
 	}
 
+	/* Configure the interrupt GPIO if available */
+	if (config->gpio_int.port) {
+		if (!device_is_ready(config->gpio_int.port)) {
+			LOG_ERR("Cannot get pointer to gpio interrupt device");
+			return -ENODEV;
+		}
+
+		rc = gpio_pin_configure_dt(&config->gpio_int, GPIO_INPUT);
+		if (rc) {
+			LOG_ERR("Failed to configure interrupt pin");
+			return rc;
+		}
+
+		gpio_init_callback(&data->cb_int, ti_hdc20xx_int_callback,
+				   BIT(config->gpio_int.pin));
+
+		rc = gpio_add_callback(config->gpio_int.port, &data->cb_int);
+		if (rc) {
+			LOG_ERR("Failed to set interrupt callback");
+			return rc;
+		}
+
+		rc = gpio_pin_interrupt_configure_dt(&config->gpio_int, GPIO_INT_EDGE_TO_ACTIVE);
+		if (rc) {
+			LOG_ERR("Failed to configure interrupt");
+			return rc;
+		}
+
+		/* Initialize the semaphore */
+		k_sem_init(&data->sem_int, 0, K_SEM_MAX_LIMIT);
+
+		/* Enable the data ready interrupt */
+		rc = i2c_reg_write_byte_dt(&config->bus, TI_HDC20XX_REG_INT_EN,
+					   TI_HDC20XX_BIT_INT_EN_DRDY_EN);
+		if (rc) {
+			LOG_ERR("Failed to enable the data ready interrupt");
+			return rc;
+		}
+
+		/* Enable the interrupt pin with level sensitive active low polarity */
+		rc = i2c_reg_write_byte_dt(&config->bus, TI_HDC20XX_REG_CONFIG,
+					   TI_HDC20XX_BIT_CONFIG_DRDY_INT_EN);
+		if (rc) {
+			LOG_ERR("Failed to enable the interrupt pin");
+			return rc;
+		}
+	}
+
 	return 0;
 }
 
@@ -175,6 +246,7 @@ static int ti_hdc20xx_init(const struct device *dev)
 	static struct ti_hdc20xx_data ti_hdc20xx_data_##compat##inst;			\
 	static const struct ti_hdc20xx_config ti_hdc20xx_config_##compat##inst = {	\
 		.bus = I2C_DT_SPEC_GET(DT_INST(inst, compat)),				\
+		.gpio_int = GPIO_DT_SPEC_GET_OR(DT_INST(inst, compat), int_gpios, {0}),	\
 	};										\
 	DEVICE_DT_DEFINE(DT_INST(inst, compat),						\
 			ti_hdc20xx_init,						\

dts/bindings/sensor/ti,hdc20xx.yaml

@@ -6,3 +6,13 @@ description: Texas Instruments HDC20XX Temperature and Humidity Sensor
 compatible: "ti,hdc20xx"
 
 include: i2c-device.yaml
+
+properties:
+    int-gpios:
+      type: phandle-array
+      required: false
+      description: DRDY/INT pin.
+
+        The DRDY/INT pin of HDC20xx sensor is open-drain, active low. If
+        connected directly the MCU pin should be configured as pull-up
+        as pull-up, active low.