samples: pwm: add the CH32V003EVT to the blinky_pwm and led/pwm samples

The CH32V003 has a single red LED that can be driven by GPIO or by CH1
of TIM2. Add to the samples.

Signed-off-by: Michael Hope <[email protected]>

Author: nzmichaelh

boards/wch/ch32v003evt/ch32v003evt-pinctrl.dtsi

@@ -18,4 +18,13 @@
 			bias-pull-up;
 		};
 	};
+
+	red_pwm_pinctrl: red_pwm_pinctrl {
+		group1 {
+			pinmux = <TIM2_CH1_PD4_0>;
+			output-high;
+			drive-push-pull;
+			slew-rate = "max-speed-10mhz";
+		};
+	};
 };

boards/wch/ch32v003evt/ch32v003evt.dts

@@ -7,6 +7,7 @@
 
 #include <wch/ch32v0/ch32v003f4p.dtsi>
 #include "ch32v003evt-pinctrl.dtsi"
+#include <zephyr/dt-bindings/pwm/pwm.h>
 
 / {
 	model = "ch32v003evt";
@@ -34,8 +35,19 @@
 		};
 	};
 
+	pwmleds: pwmleds {
+		compatible = "pwm-leds";
+		status = "disabled";
+
+		red_pwm: red_pwm0 {
+			pwms = <&tim2 0 PWM_MSEC(20) PWM_POLARITY_INVERTED>;
+			label = "Red LED";
+		};
+	};
+
 	aliases {
 		led0 = &red_led;
+		pwm-led0 = &red_pwm;
 	};
 };
 

samples/basic/blinky_pwm/boards/ch32v003evt.conf

@@ -0,0 +1,2 @@
+CONFIG_LOG_MODE_MINIMAL=y
+CONFIG_CBPRINTF_NANO=y

samples/basic/blinky_pwm/boards/ch32v003evt.overlay

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2025 Michael Hope <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	leds {
+		status = "disabled";
+	};
+};
+
+&pwmleds {
+	status = "okay";
+};
+
+&tim2 {
+	status = "okay";
+	/*
+	 * The sample runs from 1 Hz to 128 Hz, ceil(48 MHz / 65536 / 1 Hz)
+	 * is 733, and the prescaler property is one less than that.
+	*/
+	prescaler = <732>;
+	pinctrl-0 = <&red_pwm_pinctrl>;
+	pinctrl-names = "default";
+};

samples/drivers/led/pwm/boards/ch32v003evt.conf

@@ -0,0 +1,2 @@
+CONFIG_LOG_MODE_MINIMAL=y
+CONFIG_CBPRINTF_NANO=y

samples/drivers/led/pwm/boards/ch32v003evt.overlay

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2025 Michael Hope <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	leds {
+		status = "disabled";
+	};
+};
+
+&pwmleds {
+	status = "okay";
+};
+
+&tim2 {
+	status = "okay";
+	/*
+	 * The sample blinks the LED at 0.5 Hz, ceil(48 MHz / 65536 / 0.5 Hz)
+	 * is 1465, and the prescaler property is one less than that.
+	*/
+	prescaler = <1464>;
+	pinctrl-0 = <&red_pwm_pinctrl>;
+	pinctrl-names = "default";
+};