boards: nucleo_h743zi: add pwm support

Enables PWM support using the built-in red LED. Tested with:

- samples/basic/blink_led
- samples/basic/fade_led

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

boards/arm/nucleo_h743zi/Kconfig.defconfig

@@ -16,4 +16,8 @@ config I2C_1
 	default y
 	depends on I2C
 
+config PWM_STM32_12
+	default y
+	depends on PWM
+
 endif # BOARD_NUCLEO_H743ZI

boards/arm/nucleo_h743zi/doc/index.rst

@@ -109,6 +109,8 @@ features:
 +-----------+------------+-------------------------------------+
 | I2C       | on-chip    | i2c                                 |
 +-----------+------------+-------------------------------------+
+| PWM       | on-chip    | pwm                                 |
++-----------+------------+-------------------------------------+
 
 Other hardware features are not yet supported on this Zephyr port.
 

boards/arm/nucleo_h743zi/nucleo_h743zi.dts

@@ -30,9 +30,13 @@
 			gpios = <&gpiob 7 GPIO_ACTIVE_HIGH>;
 			label = "User LD2";
 		};
-		red_led: led_2 {
-			gpios = <&gpiob 14 GPIO_ACTIVE_HIGH>;
-			label = "User LD3";
+	};
+
+	pwmleds {
+		compatible = "pwm-leds";
+
+		red_pwm_led: red_pwm_led {
+			pwms = <&{/soc/timers@40001800/pwm} 1 4>;
 		};
 	};
 
@@ -47,7 +51,7 @@
 	aliases {
 		led0 = &green_led;
 		led1 = &blue_led;
-		led2 = &red_led;
+		pwm-led0 = &red_pwm_led;
 		sw0 = &user_button;
 	};
 };
@@ -65,3 +69,11 @@
 	status = "okay";
 	clock-frequency = <I2C_BITRATE_FAST>;
 };
+
+&timers12 {
+	status = "okay";
+
+	pwm {
+		status = "okay";
+	};
+};

boards/arm/nucleo_h743zi/nucleo_h743zi.yaml

@@ -15,3 +15,4 @@ supported:
   - gpio
   - counter
   - i2c
+  - pwm

boards/arm/nucleo_h743zi/pinmux.c

@@ -22,6 +22,9 @@ static const struct pin_config pinconf[] = {
 	{ STM32_PIN_PB8, STM32H7_PINMUX_FUNC_PB8_I2C1_SCL },
 	{ STM32_PIN_PB9, STM32H7_PINMUX_FUNC_PB9_I2C1_SDA },
 #endif /* CONFIG_I2C_1 */
+#ifdef CONFIG_PWM_STM32_12
+	{ STM32_PIN_PB14, STM32H7_PINMUX_FUNC_PB14_PWM12_CH1 }
+#endif /* CONFIG_PWM_STM32_12 */
 };
 
 static int pinmux_stm32_init(struct device *port)

samples/basic/blink_led/README.rst

@@ -37,6 +37,11 @@ Nucleo_L496ZG
 No special board setup is necessary because there are three on-board LEDs (red,
 green, blue) connected to the Nucleo's PWM.
 
+Nucleo_H743ZI
+=============
+No special board setup is necessary because the on-board red LED is connected
+to PWM output 12 (channel 1).
+
 Hexiwear K64
 ============
 No special board setup is necessary because there is an on-board RGB LED

samples/basic/fade_led/README.rst

@@ -30,6 +30,11 @@ Nucleo_L496ZG
 No special board setup is necessary because there are three on-board LEDs (red,
 green, blue) connected to the Nucleo's PWM.
 
+Nucleo_H743ZI
+=============
+No special board setup is necessary because the on-board red LED is connected
+to PWM output 12 (channel 1).
+
 Hexiwear K64
 ============
 No special board setup is necessary because there is an on-board RGB LED