boards: arm: sam4s_xplained: Enable PWM

Update SAM4S Xplained to support PWM. Add PWM entry to device tree and
pin control.

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>

boards/arm/sam4s_xplained/doc/index.rst

@@ -56,6 +56,8 @@ features:
 +-----------+------------+-------------------------------------+
 | SMC       | on-chip    | memc (PSRAM)                        |
 +-----------+------------+-------------------------------------+
+| PWM       | on-chip    | pwm                                 |
++-----------+------------+-------------------------------------+
 
 Other hardware features are not currently supported by Zephyr.
 

boards/arm/sam4s_xplained/sam4s_xplained-pinctrl.dtsi

@@ -41,6 +41,13 @@
 				 <PA22A_USART1_TXD>;
 		};
 	};
+	pwm0_default: pwm0_default {
+		group1 {
+			pinmux = <PA12B_PWM_PWMH1>,
+				 <PA13B_PWM_PWMH2>,
+				 <PA14B_PWM_PWMH3>;
+		};
+	};
 	smc_default: smc_default {
 		group1 {
 			pinmux = <PC18A_EBI_A0>,

boards/arm/sam4s_xplained/sam4s_xplained.dts

@@ -15,6 +15,7 @@
 	aliases {
 		i2c-0 = &twi0;
 		i2c-1 = &twi1;
+		pwm-0 = &pwm0;
 		led0 = &yellow_led_1;
 		led1 = &yellow_led_2;
 		sw0 = &user_button;
@@ -168,6 +169,13 @@
 	pinctrl-names = "default";
 };
 
+&pwm0 {
+	status = "okay";
+
+	pinctrl-0 = <&pwm0_default>;
+	pinctrl-names = "default";
+};
+
 &wdt {
 	status = "okay";
 };

boards/arm/sam4s_xplained/sam4s_xplained.yaml

@@ -9,6 +9,7 @@ toolchain:
 supported:
   - gpio
   - memc
+  - pwm
   - spi
   - watchdog
   - xplained_gpio