drivers: apds9960: use interrupt output for sample

This patch changes the behavior of the sensor. The sensor
will remain in sleep mode after initialization and will only
run the measurements once when sample_fetch is called.
This optimizes the power consumption of the sensor as it
stays in sleep mode most of the time.

Signed-off-by: Johann Fischer <j.fischer@phytec.de>

boards/arm/reel_board/dts.fixup

@@ -13,3 +13,5 @@
 
 #define CONFIG_APDS9960_DRV_NAME		NORDIC_NRF_I2C_40003000_AVAGO_APDS9960_29_LABEL
 #define CONFIG_APDS9960_I2C_DEV_NAME		NORDIC_NRF_I2C_40003000_AVAGO_APDS9960_29_BUS_NAME
+#define CONFIG_APDS9960_GPIO_DEV_NAME		NORDIC_NRF_I2C_40003000_AVAGO_APDS9960_29_INT_GPIOS_CONTROLLER
+#define CONFIG_APDS9960_GPIO_PIN_NUM		NORDIC_NRF_I2C_40003000_AVAGO_APDS9960_29_INT_GPIOS_PIN

drivers/sensor/apds9960/Kconfig

@@ -1,5 +1,6 @@
 #
 # Copyright (c) 2017 Intel Corporation
+# Copyright (c) 2018 Phytec Messtechnik GmbH
 #
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -29,4 +30,21 @@ config APDS9960_DRV_NAME
 
 endif # !HAS_DTS_I2C_DEVICE
 
+if !HAS_DTS_GPIO_DEVICE
+
+config APDS9960_GPIO_DEV_NAME
+	string "GPIO device"
+	default "GPIO_0"
+	help
+	  The GPIO device's name where the APDS9960 interrupt pin is connected.
+
+config APDS9960_GPIO_PIN_NUM
+	int "Interrupt GPIO pin number"
+	default 0
+	help
+	  The GPIO pin number receiving the interrupt signal from the
+	  APDS9960 sensor.
+
+endif # !HAS_DTS_GPIO_DEVICE
+
 endif # APDS9960

drivers/sensor/apds9960/apds9960.c

@@ -21,22 +21,70 @@
 
 #include "apds9960.h"
 
+static void apds9960_gpio_callback(struct device *dev,
+				  struct gpio_callback *cb, u32_t pins)
+{
+	struct apds9960_data *drv_data =
+		CONTAINER_OF(cb, struct apds9960_data, gpio_cb);
+
+	gpio_pin_disable_callback(dev, CONFIG_APDS9960_GPIO_PIN_NUM);
+
+	k_sem_give(&drv_data->data_sem);
+}
+
 static int apds9960_sample_fetch(struct device *dev, enum sensor_channel chan)
 {
 	struct apds9960_data *data = dev->driver_data;
+	u8_t status;
 
 	__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
 
-	/* Read CRGB registers */
-	if (i2c_burst_read(data->i2c, APDS9960_I2C_ADDRESS,
-			   APDS9960_CDATAL_REG,
-			   (u8_t *)&data->sample_crgb,
-			   sizeof(data->sample_crgb))) {
+	SYS_LOG_DBG("");
+	gpio_pin_enable_callback(data->gpio,
+				 CONFIG_APDS9960_GPIO_PIN_NUM);
+
+	if (i2c_reg_update_byte(data->i2c, APDS9960_I2C_ADDRESS,
+				APDS9960_ENABLE_REG,
+				APDS9960_ENABLE_PON | APDS9960_ENABLE_AIEN,
+				APDS9960_ENABLE_PON | APDS9960_ENABLE_AIEN)) {
+		SYS_LOG_ERR("Power on bit not set.");
 		return -EIO;
 	}
 
+	k_sem_take(&data->data_sem, K_FOREVER);
+
 	if (i2c_reg_read_byte(data->i2c, APDS9960_I2C_ADDRESS,
-			      APDS9960_PDATA_REG, &data->pdata)) {
+			      APDS9960_STATUS_REG, &status)) {
+		return -EIO;
+	}
+
+	SYS_LOG_DBG("status: 0x%x", status);
+	if (status & APDS9960_STATUS_PINT) {
+		if (i2c_reg_read_byte(data->i2c, APDS9960_I2C_ADDRESS,
+				      APDS9960_PDATA_REG, &data->pdata)) {
+			return -EIO;
+		}
+	}
+
+	if (status & APDS9960_STATUS_AINT) {
+		if (i2c_burst_read(data->i2c, APDS9960_I2C_ADDRESS,
+				   APDS9960_CDATAL_REG,
+				   (u8_t *)&data->sample_crgb,
+				   sizeof(data->sample_crgb))) {
+			return -EIO;
+		}
+
+	}
+
+	if (i2c_reg_update_byte(data->i2c, APDS9960_I2C_ADDRESS,
+				APDS9960_ENABLE_REG,
+				APDS9960_ENABLE_PON,
+				0)) {
+		return -EIO;
+	}
+
+	if (i2c_reg_write_byte(data->i2c, APDS9960_I2C_ADDRESS,
+			       APDS9960_AICLEAR_REG, 0)) {
 		return -EIO;
 	}
 
@@ -237,6 +285,13 @@ static int apds9960_sensor_setup(struct device *dev)
 		return -EIO;
 	}
 
+	if (i2c_reg_write_byte(data->i2c, APDS9960_I2C_ADDRESS,
+			       APDS9960_CONFIG3_REG,
+			       APDS9960_CONFIG3_SAI)) {
+		SYS_LOG_ERR("Configuration Register Three not set");
+		return -EIO;
+	}
+
 	if (i2c_reg_write_byte(data->i2c, APDS9960_I2C_ADDRESS,
 			       APDS9960_PERS_REG,
 			       APDS9960_DEFAULT_PERS)) {
@@ -254,25 +309,46 @@ static int apds9960_sensor_setup(struct device *dev)
 		return -EIO;
 	}
 
-	if (i2c_reg_update_byte(data->i2c, APDS9960_I2C_ADDRESS,
-				APDS9960_ENABLE_REG,
-				APDS9960_ENABLE_PON, APDS9960_ENABLE_PON)) {
-		SYS_LOG_ERR("Power on bit not set");
+	return 0;
+}
+
+static int apds9960_init_interrupt(struct device *dev)
+{
+	struct apds9960_data *drv_data = dev->driver_data;
+
+	/* setup gpio interrupt */
+	drv_data->gpio = device_get_binding(CONFIG_APDS9960_GPIO_DEV_NAME);
+	if (drv_data->gpio == NULL) {
+		SYS_LOG_ERR("Failed to get pointer to %s device!",
+			    CONFIG_APDS9960_GPIO_DEV_NAME);
+		return -EINVAL;
+	}
+
+	gpio_pin_configure(drv_data->gpio, CONFIG_APDS9960_GPIO_PIN_NUM,
+			   GPIO_DIR_IN | GPIO_INT | GPIO_INT_EDGE |
+			   GPIO_INT_ACTIVE_LOW | GPIO_INT_DEBOUNCE |
+			   GPIO_PUD_PULL_UP);
+
+	gpio_init_callback(&drv_data->gpio_cb,
+			   apds9960_gpio_callback,
+			   BIT(CONFIG_APDS9960_GPIO_PIN_NUM));
+
+	if (gpio_add_callback(drv_data->gpio, &drv_data->gpio_cb) < 0) {
+		SYS_LOG_DBG("Failed to set gpio callback!");
 		return -EIO;
 	}
 
+	k_sem_init(&drv_data->data_sem, 0, UINT_MAX);
+
 	return 0;
 }
 
-static const struct sensor_driver_api apds9960_driver_api = {
-	.sample_fetch = &apds9960_sample_fetch,
-	.channel_get = &apds9960_channel_get,
-};
-
 static int apds9960_init(struct device *dev)
 {
 	struct apds9960_data *data = dev->driver_data;
 
+	/* Initialize time 5.7ms */
+	k_sleep(6);
 	data->i2c = device_get_binding(CONFIG_APDS9960_I2C_DEV_NAME);
 
 	if (data->i2c == NULL) {
@@ -286,11 +362,21 @@ static int apds9960_init(struct device *dev)
 
 	apds9960_sensor_setup(dev);
 
+	if (apds9960_init_interrupt(dev) < 0) {
+		SYS_LOG_ERR("Failed to initialize interrupt!");
+		return -EIO;
+	}
+
 	return 0;
 }
 
+static const struct sensor_driver_api apds9960_driver_api = {
+	.sample_fetch = &apds9960_sample_fetch,
+	.channel_get = &apds9960_channel_get,
+};
+
 static struct apds9960_data apds9960_data;
 
 DEVICE_AND_API_INIT(apds9960, CONFIG_APDS9960_DRV_NAME, &apds9960_init,
-		&apds9960_data, NULL, POST_KERNEL,
-		CONFIG_SENSOR_INIT_PRIORITY, &apds9960_driver_api);
+		    &apds9960_data, NULL, POST_KERNEL,
+		    CONFIG_SENSOR_INIT_PRIORITY, &apds9960_driver_api);

drivers/sensor/apds9960/apds9960.h

@@ -8,6 +8,8 @@
 #ifndef ZEPHYR_DRIVERS_SENSOR_APDS9960_APDS9960_H_
 #define ZEPHYR_DRIVERS_SENSOR_APDS9960_APDS9960_H_
 
+#include <gpio.h>
+
 #define APDS9960_I2C_ADDRESS		0x39
 
 #define APDS9960_ENABLE_REG		0x80
@@ -210,8 +212,14 @@
 
 struct apds9960_data {
 	struct device *i2c;
+	struct device *gpio;
+	struct gpio_callback gpio_cb;
+	struct k_work work;
+	struct device *dev;
 	u16_t sample_crgb[4];
 	u8_t pdata;
+
+	struct k_sem data_sem;
 };
 
 #define SYS_LOG_DOMAIN "APDS9960"