dts/boards: efr32bg_sltb010a: add spi-through-usart nodes

This commit configures USART0 to act as SPI.

Signed-off-by: Pawel Czarnecki <[email protected]>

Author: lpawelcz

boards/arm/efr32bg_sltb010a/efr32bg_sltb010a.dts

@@ -16,6 +16,8 @@
 	aliases {
 		led0 = &led0;
 		sw0 = &button0;
+		spi-flash0 = &mx25r80;
+		spi0 = &usart0;
 	};
 
 	chosen {
@@ -52,6 +54,28 @@
 	clock-frequency = <76800000>;
 };
 
+&usart0 {
+	status = "okay";
+	pinctrl-0 = <&usart0_default>;
+	pinctrl-names = "default";
+
+	cs-gpios = <&gpioc 3 GPIO_ACTIVE_LOW>;
+
+	mx25r80: mx25r8035f@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <80000000>;
+		size = <0x800000>;
+		jedec-id = [c2 28 14];
+		sfdp-bfp = [
+			 e5 20 f1 ff  ff ff 7f 00  44 eb 08 6b  08 3b 04 bb
+			 ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
+			 10 d8 00 ff  23 72 f5 00  82 ed 04 b7  44 83 38 44
+			 30 b0 30 b0  f7 c4 d5 5c  00 be 29 ff  f0 d0 ff ff
+		];
+	};
+};
+
 &usart1 {
 	current-speed = <115200>;
 	status = "okay";
@@ -112,6 +136,10 @@
 	status = "okay";
 };
 
+&gpioc {
+	status = "okay";
+};
+
 &stimer0 {
 	status = "okay";
 };

dts/arm/silabs/efr32bg22-pinctrl.dtsi

@@ -7,17 +7,16 @@
 #include <dt-bindings/pinctrl/gecko-pinctrl.h>
 
 &pinctrl {
-	/* configuration for uart0 device, default state */
+	/* configuration for usart0 device, operating as SPI */
 	usart0_default: usart0_default {
 		group1 {
-			/* configure PE.11 as UART_RX and PE.10 as UART_TX */
-			psels = <GECKO_PSEL(UART_TX, E, 10)>,
-				<GECKO_PSEL(UART_RX, E, 11)>,
-				<GECKO_LOC(UART, 0)>;
+			psels = <GECKO_PSEL(SPI_SCK, C, 2)>,
+				<GECKO_PSEL(SPI_MOSI, C, 0)>,
+				<GECKO_PSEL(SPI_MISO, C, 1)>;
 		};
 	};
 
-	/* configuration for uart1 device, default state */
+	/* configuration for usart1 device, default state - operating as UART */
 	usart1_default: usart1_default {
 		group1 {
 			/* configure PA.6 as UART_RX and PA.5 as UART_TX */

dts/arm/silabs/efr32bg22.dtsi

@@ -55,11 +55,16 @@
 		};
 
 		usart0: usart@5005c000 {
-			compatible = "silabs,gecko-usart";
+			compatible = "silabs,gecko-spi-usart";
 			reg = <0x5005C000 0x400>;
 			interrupts = <13 0>, <14 0>;
 			interrupt-names = "rx", "tx";
 			status = "disabled";
+
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			status = "disabled";
 		};
 
 		usart1: usart@50060000 {