boards: stm32f411e_disco: Add pwm to drive green led

This enables the fade_led example to work with this board.

Signed-off-by: Pauli Salmenrinne <susundberg@gmail.com>

boards/arm/stm32f411e_disco/Kconfig.defconfig

@@ -13,6 +13,14 @@ if UART_CONSOLE
 config UART_2
 	default y
 
+
+if PWM
+
+config PWM_STM32_4
+	default y
+
+endif # PWM
+
 endif # UART_CONSOLE
 
 endif # BOARD_STM32F411E_DISCO

boards/arm/stm32f411e_disco/doc/index.rst

@@ -83,6 +83,8 @@ hardware features:
 +-----------+------------+-------------------------------------+
 | GPIO      | on-chip    | gpio                                |
 +-----------+------------+-------------------------------------+
+| PWM       | on-chip    | pwm                                 |
++-----------+------------+-------------------------------------+
 
 Other hardware features are not yet supported on Zephyr porting.
 
@@ -103,7 +105,7 @@ Default Zephyr Peripheral Mapping:
 - UART_2_TX : PA2
 - UART_2_RX : PA3
 - LD3 : PD13
-- LD4 : PD12
+- LD4 : PD12 (PWM4 CH1)
 - LD5 : PD14
 - LD6 : PD15
 

boards/arm/stm32f411e_disco/pinmux.c

@@ -18,6 +18,9 @@ static const struct pin_config pinconf[] = {
 	{STM32_PIN_PA2, STM32F4_PINMUX_FUNC_PA2_USART2_TX},
 	{STM32_PIN_PA3, STM32F4_PINMUX_FUNC_PA3_USART2_RX},
 #endif	/* CONFIG_UART_2 */
+#ifdef CONFIG_PWM_STM32_4
+	{STM32_PIN_PD12, STM32F4_PINMUX_FUNC_PD12_PWM4_CH1 },
+ #endif /* CONFIG_PWM_STM32_4 */
 };
 
 static int pinmux_stm32_init(struct device *port)

boards/arm/stm32f411e_disco/stm32f411e_disco.dts

@@ -38,6 +38,13 @@
 		};
 	};
 
+	pwmleds {
+		compatible = "pwm-leds";
+		green_pwm_led: green_pwm_led {
+			pwms = <&{/soc/timers@40000800/pwm} 1 0>;
+		};
+	};
+
 	gpio_keys {
 		compatible = "gpio-keys";
 		user_button: button {
@@ -52,9 +59,19 @@
 		led2 = &red_led_5;
 		led3 = &blue_led_6;
 		sw0 = &user_button;
+		pwm-led0 = &green_pwm_led;
 	};
 };
 
+&timers4 {
+	status = "okay";
+
+	pwm {
+		status = "okay";
+	};
+};
+
+
 &usart2 {
 	current-speed = <115200>;
 	status = "okay";

drivers/pinmux/stm32/pinmux_stm32f4.h

@@ -407,6 +407,8 @@
 
 #define STM32F4_PINMUX_FUNC_PD12_USART3_RTS \
 	(STM32_PINMUX_ALT_FUNC_7 | STM32_OPENDRAIN_PULLUP)
+#define STM32F4_PINMUX_FUNC_PD12_PWM4_CH1    \
+	(STM32_PINMUX_ALT_FUNC_2 | STM32_PUSHPULL_NOPULL)
 
 #define STM32F4_PINMUX_FUNC_PD14_PWM4_CH3    \
 	(STM32_PINMUX_ALT_FUNC_2 | STM32_PUSHPULL_NOPULL)