sensor: dht: convert from Kconfig to devicetree

Define a binding for the Aosong DHT family of temperature/humidity
sensors.  Remove the Kconfig settings, and update the driver to use
devicetree information.

Signed-off-by: Peter Bigot <[email protected]>

Author: pabigot

drivers/sensor/dht/Kconfig

@@ -3,50 +3,8 @@
 # Copyright (c) 2016 Intel Corporation
 # SPDX-License-Identifier: Apache-2.0
 
-menuconfig DHT
+config DHT
 	bool "DHT Temperature and Humidity Sensor"
 	depends on GPIO
 	help
 	  Enable driver for the DHT temperature and humidity sensor family.
-
-if DHT
-
-choice
-	prompt "Chip type"
-	default DHT_CHIP_DHT11
-	help
-	  Choose desired chip type from the DHT family.
-
-config DHT_CHIP_DHT11
-	bool "DHT11"
-	help
-	  Choose this option to enable the DHT11 chip.
-
-config DHT_CHIP_DHT22
-	bool "DHT22"
-	help
-	  Choose this option to enable the DHT22 chip.
-
-endchoice
-
-config DHT_NAME
-	string "Driver name"
-	default "DHT11" if DHT_CHIP_DHT11
-	default "DHT22" if DHT_CHIP_DHT22
-	help
-	  Device name with which the sensor is identified.
-
-config DHT_GPIO_DEV_NAME
-	string "GPIO device"
-	default "GPIO_0"
-	help
-	  The device name of the GPIO device to which the chip's data pin
-	  is connected.
-
-config DHT_GPIO_PIN_NUM
-	int "Interrupt GPIO pin number"
-	default 0
-	help
-	  The number of the GPIO on which the chip's data pin is connected.
-
-endif # DHT

drivers/sensor/dht/dht.c

@@ -26,9 +26,11 @@ LOG_MODULE_REGISTER(DHT, CONFIG_SENSOR_LOG_LEVEL);
  * @return duration in usec of signal being measured,
  *         -1 if duration exceeds DHT_SIGNAL_MAX_WAIT_DURATION
  */
-static s8_t dht_measure_signal_duration(struct dht_data *drv_data,
-					  u32_t signal_val)
+static s8_t dht_measure_signal_duration(struct device *dev,
+					u32_t signal_val)
 {
+	struct dht_data *drv_data = dev->driver_data;
+	const struct dht_config *cfg = dev->config->config_info;
 	u32_t val;
 	u32_t elapsed_cycles;
 	u32_t max_wait_cycles = (u32_t)(
@@ -39,7 +41,7 @@ static s8_t dht_measure_signal_duration(struct dht_data *drv_data,
 	u32_t start_cycles = k_cycle_get_32();
 
 	do {
-		gpio_pin_read(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM, &val);
+		gpio_pin_read(drv_data->gpio, cfg->pin, &val);
 		elapsed_cycles = k_cycle_get_32() - start_cycles;
 
 		if (elapsed_cycles > max_wait_cycles) {
@@ -55,6 +57,7 @@ static s8_t dht_measure_signal_duration(struct dht_data *drv_data,
 static int dht_sample_fetch(struct device *dev, enum sensor_channel chan)
 {
 	struct dht_data *drv_data = dev->driver_data;
+	const struct dht_config *cfg = dev->config->config_info;
 	int ret = 0;
 	s8_t signal_duration[DHT_DATA_BITS_NUM];
 	s8_t max_duration, min_duration, avg_duration;
@@ -64,44 +67,44 @@ static int dht_sample_fetch(struct device *dev, enum sensor_channel chan)
 	__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
 
 	/* send start signal */
-	gpio_pin_write(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM, 0);
+	gpio_pin_write(drv_data->gpio, cfg->pin, 0);
 
 	k_busy_wait(DHT_START_SIGNAL_DURATION);
 
-	gpio_pin_write(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM, 1);
+	gpio_pin_write(drv_data->gpio, cfg->pin, 1);
 
 	/* switch to DIR_IN to read sensor signals */
-	gpio_pin_configure(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM,
+	gpio_pin_configure(drv_data->gpio, cfg->pin,
 			   GPIO_DIR_IN);
 
 	/* wait for sensor response */
-	if (dht_measure_signal_duration(drv_data, 1) == -1) {
+	if (dht_measure_signal_duration(dev, 1) == -1) {
 		ret = -EIO;
 		goto cleanup;
 	}
 
 	/* read sensor response */
-	if (dht_measure_signal_duration(drv_data, 0) == -1) {
+	if (dht_measure_signal_duration(dev, 0) == -1) {
 		ret = -EIO;
 		goto cleanup;
 	}
 
 	/* wait for sensor data */
-	if (dht_measure_signal_duration(drv_data, 1) == -1) {
+	if (dht_measure_signal_duration(dev, 1) == -1) {
 		ret = -EIO;
 		goto cleanup;
 	}
 
 	/* read sensor data */
 	for (i = 0U; i < DHT_DATA_BITS_NUM; i++) {
 		/* LOW signal to indicate a new bit */
-		if (dht_measure_signal_duration(drv_data, 0) == -1) {
+		if (dht_measure_signal_duration(dev, 0) == -1) {
 			ret = -EIO;
 			goto cleanup;
 		}
 
 		/* HIGH signal duration indicates bit value */
-		signal_duration[i] = dht_measure_signal_duration(drv_data, 1);
+		signal_duration[i] = dht_measure_signal_duration(dev, 1);
 		if (signal_duration[i] == -1) {
 			ret = -EIO;
 			goto cleanup;
@@ -152,9 +155,8 @@ static int dht_sample_fetch(struct device *dev, enum sensor_channel chan)
 
 cleanup:
 	/* switch to DIR_OUT and leave pin to HIGH until next fetch */
-	gpio_pin_configure(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM,
-			   GPIO_DIR_OUT);
-	gpio_pin_write(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM, 1);
+	gpio_pin_configure(drv_data->gpio, cfg->pin, GPIO_DIR_OUT);
+	gpio_pin_write(drv_data->gpio, cfg->pin, 1);
 
 	return ret;
 }
@@ -165,45 +167,48 @@ static int dht_channel_get(struct device *dev,
 {
 	struct dht_data *drv_data = dev->driver_data;
 
-	__ASSERT_NO_MSG(chan == SENSOR_CHAN_AMBIENT_TEMP || chan == SENSOR_CHAN_HUMIDITY);
+	__ASSERT_NO_MSG(chan == SENSOR_CHAN_AMBIENT_TEMP
+			|| chan == SENSOR_CHAN_HUMIDITY);
 
 	/* see data calculation example from datasheet */
-#if defined(CONFIG_DHT_CHIP_DHT11)
-	/* use only integral data byte */
-	if (chan == SENSOR_CHAN_HUMIDITY) {
-		val->val1 = drv_data->sample[0];
-		val->val2 = 0;
-	} else { /* chan == SENSOR_CHAN_AMBIENT_TEMP */
-		val->val1 = drv_data->sample[2];
-		val->val2 = 0;
-	}
-#elif defined(CONFIG_DHT_CHIP_DHT22)
-	/*
-	 * use both integral and decimal data bytes; resulted 16bit data has
-	 * a resolution of 0.1 units
-	 */
-	s16_t raw_val, sign;
-
-	if (chan == SENSOR_CHAN_HUMIDITY) {
-		raw_val = (drv_data->sample[0] << 8) | drv_data->sample[1];
-		val->val1 = raw_val / 10;
-		val->val2 = (raw_val % 10) * 100000;
-	} else { /* chan == SENSOR_CHAN_AMBIENT_TEMP */
-		raw_val = (drv_data->sample[2] << 8) | drv_data->sample[3];
-
-		sign = raw_val & 0x8000;
-		raw_val = raw_val & ~0x8000;
-
-		val->val1 = raw_val / 10;
-		val->val2 = (raw_val % 10) * 100000;
-
-		/* handle negative value */
-		if (sign) {
-			val->val1 = -val->val1;
-			val->val2 = -val->val2;
+	if (IS_ENABLED(DT_INST_0_AOSONG_DHT_DHT22)) {
+		/*
+		 * use both integral and decimal data bytes; resulted
+		 * 16bit data has a resolution of 0.1 units
+		 */
+		s16_t raw_val, sign;
+
+		if (chan == SENSOR_CHAN_HUMIDITY) {
+			raw_val = (drv_data->sample[0] << 8)
+				+ drv_data->sample[1];
+			val->val1 = raw_val / 10;
+			val->val2 = (raw_val % 10) * 100000;
+		} else { /* chan == SENSOR_CHAN_AMBIENT_TEMP */
+			raw_val = (drv_data->sample[2] << 8)
+				+ drv_data->sample[3];
+
+			sign = raw_val & 0x8000;
+			raw_val = raw_val & ~0x8000;
+
+			val->val1 = raw_val / 10;
+			val->val2 = (raw_val % 10) * 100000;
+
+			/* handle negative value */
+			if (sign) {
+				val->val1 = -val->val1;
+				val->val2 = -val->val2;
+			}
+		}
+	} else {
+		/* use only integral data byte */
+		if (chan == SENSOR_CHAN_HUMIDITY) {
+			val->val1 = drv_data->sample[0];
+			val->val2 = 0;
+		} else { /* chan == SENSOR_CHAN_AMBIENT_TEMP */
+			val->val1 = drv_data->sample[2];
+			val->val2 = 0;
 		}
 	}
-#endif
 
 	return 0;
 }
@@ -215,23 +220,30 @@ static const struct sensor_driver_api dht_api = {
 
 static int dht_init(struct device *dev)
 {
+	int rc = 0;
 	struct dht_data *drv_data = dev->driver_data;
+	const struct dht_config *cfg = dev->config->config_info;
 
-	drv_data->gpio = device_get_binding(CONFIG_DHT_GPIO_DEV_NAME);
+	drv_data->gpio = device_get_binding(cfg->ctrl);
 	if (drv_data->gpio == NULL) {
-		LOG_ERR("Failed to get GPIO device.");
+		LOG_ERR("Failed to get GPIO device %s.", cfg->ctrl);
 		return -EINVAL;
 	}
 
-	gpio_pin_configure(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM,
-			   GPIO_DIR_OUT);
-
-	gpio_pin_write(drv_data->gpio, CONFIG_DHT_GPIO_PIN_NUM, 1);
+	rc = gpio_pin_configure(drv_data->gpio, cfg->pin, GPIO_DIR_OUT);
+	if (rc == 0) {
+		rc = gpio_pin_write(drv_data->gpio, cfg->pin, 1);
+	}
 
-	return 0;
+	return rc;
 }
 
-struct dht_data dht_data;
+static struct dht_data dht_data;
+static const struct dht_config dht_config = {
+	.ctrl = DT_INST_0_AOSONG_DHT_DIO_GPIOS_CONTROLLER,
+	.pin = DT_INST_0_AOSONG_DHT_DIO_GPIOS_PIN,
+};
 
-DEVICE_AND_API_INIT(dht_dev, CONFIG_DHT_NAME, &dht_init, &dht_data,
-		    NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, &dht_api);
+DEVICE_AND_API_INIT(dht_dev, DT_INST_0_AOSONG_DHT_LABEL, &dht_init,
+		    &dht_data, &dht_config,
+		    POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, &dht_api);

drivers/sensor/dht/dht.h

@@ -18,4 +18,9 @@ struct dht_data {
 	u8_t sample[4];
 };
 
+struct dht_config {
+	const char *ctrl;
+	u8_t pin;
+};
+
 #endif

dts/bindings/sensor/aosong,dht.yaml

@@ -0,0 +1,29 @@
+# Copyright (c) 2019 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+title: Aosong DHT Digital-output Humidity and Temperature Sensor
+
+description: |
+    The Aosong DHT family of sensors provide temperature and humidity
+    measurements through a bidirectional serial digital signal.  The
+    DHT11 uses a polymer humidity capacitor with NTC thermistor; the
+    DHT22 replaces the thermistor with a DS18B20 1-wire thermometer.
+
+    The DHT22 is also known as an AM2303.
+
+compatible: "aosong,dht"
+
+include: base.yaml
+
+properties:
+  dio-gpios:
+    type: phandle-array
+    required: true
+    description: |
+      Pin on which sensor communication will be performed.
+
+  dht22:
+    type: boolean
+    description: |
+      Set to identify sensor as a DHT22/AM2303.  Leave unset to identify
+      sensor as a DHT11.

tests/drivers/build_all/dts_fixup.h

@@ -62,6 +62,13 @@
 #define DT_INST_0_AMS_CCS811_BASE_ADDRESS 0
 #endif
 
+#ifndef DT_INST_0_AOSONG_DHT_LABEL
+#define DT_INST_0_AOSONG_DHT_LABEL ""
+#define DT_INST_0_AOSONG_DHT_DIO_GPIOS_CONTROLLER ""
+#define DT_INST_0_AOSONG_DHT_DIO_GPIOS_PIN 0
+#define DT_INST_0_AOSONG_DHT_DIO_GPIOS_FLAGS 0
+#endif
+
 #ifndef DT_INST_0_NXP_FXAS21002_LABEL
 #define DT_INST_0_NXP_FXAS21002_LABEL ""
 #define DT_INST_0_NXP_FXAS21002_BASE_ADDRESS 0