boards: Enabling neopixel on Adafruit Qt Py RP2040

Using the recently added WS2812 PIO driver, this enables the LED on the
QT PY to work with the built in RGB LED examples.

Signed-off-by: Ian Wakely <[email protected]>

Author: raveious

boards/arm/adafruit_qt_py_rp2040/adafruit_qt_py_rp2040-pinctrl.dtsi

@@ -61,4 +61,10 @@
 
 	clocks_default: clocks_default {
 	};
+
+	ws2812_pio1_default: ws2812_pio1_default {
+		ws2812 {
+			pinmux = <PIO1_P12>;
+		};
+	};
 };

boards/arm/adafruit_qt_py_rp2040/adafruit_qt_py_rp2040.dts

@@ -11,6 +11,7 @@
 #include "adafruit_qt_py_rp2040-pinctrl.dtsi"
 #include "seeed_xiao_connector.dtsi"
 #include <freq.h>
+#include <zephyr/dt-bindings/led/led.h>
 
 / {
 	chosen {
@@ -24,6 +25,7 @@
 
 	aliases {
 		watchdog0 = &wdt0;
+		led-strip = &ws2812;
 	};
 };
 
@@ -68,6 +70,17 @@
 
 &gpio0 {
 	status = "okay";
+
+	/*
+	 * Unlike some of the other Adafruit boards, the neopixel on this board has
+	 * its positive side hooked up to a GPIO pin rather than a positive voltage
+	 * rail to save on power. This will enable the LED on board initialization.
+	 */
+	neopixel-power-enable {
+		gpio-hog;
+		gpios = <11 GPIO_ACTIVE_HIGH>;
+		output-high;
+	};
 };
 
 &i2c0 {
@@ -109,6 +122,33 @@
 	status = "okay";
 };
 
+&pio1 {
+	status = "okay";
+
+	/*
+	 * Need to put this on PIO1 as having this on PIO0 causes the GPIO hog to
+	 * not work.
+	 */
+	pio-ws2812 {
+		compatible = "worldsemi,ws2812-rpi_pico-pio";
+		status = "okay";
+		pinctrl-0 = <&ws2812_pio1_default>;
+		pinctrl-names = "default";
+		bit-waveform = <3>, <3>, <4>;
+
+		ws2812: ws2812 {
+			status = "okay";
+			output-pin = <12>;
+			chain-length = <1>;
+			color-mapping = <LED_COLOR_ID_GREEN
+					 LED_COLOR_ID_RED
+					 LED_COLOR_ID_BLUE>;
+			reset-delay = <280>;
+			frequency = <800000>;
+		};
+	};
+};
+
 zephyr_udc0: &usbd {
 	status = "okay";
 };

samples/drivers/led_ws2812/boards/adafruit_qt_py_rp2040.conf

@@ -0,0 +1,3 @@
+CONFIG_WS2812_STRIP_RPI_PICO_PIO=y
+CONFIG_GPIO=y
+CONFIG_GPIO_HOGS=y