boards: nordic: thingy53: Add missing FEM entries

Adds missing SPI definition and settings for usage of FEM on
this platform

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

boards/nordic/thingy53/thingy53_nrf5340_common.dtsi

@@ -131,6 +131,18 @@
 		};
 	};
 
+	/* Disabled by default as SPI lines are shared with peripherals on application core */
+	spi_fwd: nrf-spi-forwarder {
+		compatible = "nordic,nrf-gpio-forwarder";
+		status = "disabled";
+		fem-spi-if {
+			gpios = <&gpio0 24 0>,
+				<&gpio0 29 0>,
+				<&gpio0 27 0>,
+				<&gpio0 28 0>;
+		};
+	};
+
 	aliases {
 		sw0 = &button0;
 		sw1 = &button1;

boards/nordic/thingy53/thingy53_nrf5340_cpunet-pinctrl.dtsi

@@ -23,4 +23,20 @@
 		};
 	};
 
+	spi0_default: spi0_default {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 0, 29)>,
+				<NRF_PSEL(SPIM_MISO, 0, 27)>,
+				<NRF_PSEL(SPIM_MOSI, 0, 28)>;
+		};
+	};
+
+	spi0_sleep: spi0_sleep {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 0, 29)>,
+				<NRF_PSEL(SPIM_MISO, 0, 27)>,
+				<NRF_PSEL(SPIM_MOSI, 0, 28)>;
+			low-power-enable;
+		};
+	};
 };

boards/nordic/thingy53/thingy53_nrf5340_cpunet.dts

@@ -63,6 +63,7 @@
 		mode-gpios  = <&gpio1 12 GPIO_ACTIVE_HIGH>;
 		pdn-gpios   = <&gpio1 10 GPIO_ACTIVE_HIGH>;
 		tx-en-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;
+		spi-if = <&nrf_radio_fem_spi>;
 		supply-voltage-mv = <3000>;
 	};
 
@@ -111,6 +112,27 @@
 	pinctrl-names = "default", "sleep";
 };
 
+/* Disabled by default as shares same GPIO lines as SPI peripherals on application core */
+fem_spi: &spi0 {
+	status = "disabled";
+	cs-gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-1 = <&spi0_sleep>;
+	pinctrl-names = "default", "sleep";
+
+	nrf_radio_fem_spi: nrf21540_fem_spi@0 {
+		compatible = "nordic,nrf21540-fem-spi";
+		status = "disabled";
+		reg = <0>;
+		spi-max-frequency = <8000000>;
+	};
+};
+
+&radio {
+	/* Uncomment to enable SPI interface for FEM */
+	/* fem = <&nrf_radio_fem>; */
+};
+
 &flash1 {
 
 	partitions {