tests: drivers: spi: loopback: Add test for pico-spi-pio driver with DMA.

With the addition of a new overlay file that specifies DMA channels.

Signed-off-by: Terry Geng <[email protected]>

Author: TerryGeng

tests/drivers/spi/spi_loopback/boards/rpi_pico_pio_dma.overlay

@@ -0,0 +1,50 @@
+#include <zephyr/dt-bindings/dma/rpi-pico-dma-rp2040.h>
+
+&dma {
+	status = "okay";
+};
+
+&pinctrl {
+	pio0_spi0_default: pio0_spi0_default {
+		/* gpio 17 is used for chip select, not assigned to the PIO */
+		group1 {
+			pinmux = <PIO0_P18>, <PIO0_P19>;
+		};
+		group2 {
+			pinmux = <PIO0_P16>;
+			input-enable;
+		};
+	};
+};
+
+&pio0 {
+	status = "okay";
+
+	pio0_spi0: pio0_spi0 {
+		pinctrl-0 = <&pio0_spi0_default>;
+		pinctrl-names = "default";
+
+		compatible = "raspberrypi,pico-spi-pio";
+		status = "okay";
+		dmas = <&dma 0 0 0>, <&dma 1 0 0>;
+		dma-names = "tx", "rx";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&clocks RPI_PICO_CLKID_CLK_SYS>;
+		miso-gpios = <&gpio0 16 0>;
+		cs-gpios = <&gpio0 17 GPIO_ACTIVE_LOW>;
+		clk-gpios = <&gpio0 18 GPIO_ACTIVE_HIGH>;
+		mosi-gpios = <&gpio0 19 GPIO_ACTIVE_HIGH>;
+
+		slow@0 {
+			compatible = "test-spi-loopback-slow";
+			reg = <0>;
+			spi-max-frequency = <500000>;
+		};
+		fast@0 {
+			compatible = "test-spi-loopback-fast";
+			reg = <0>;
+			spi-max-frequency = <14000000>;
+		};
+	};
+};

tests/drivers/spi/spi_loopback/testcase.yaml

@@ -205,6 +205,15 @@ tests:
       - DTC_OVERLAY_FILE="boards/rpi_pico_pio.overlay"
       - EXTRA_CONF_FILE="overlay-rpi-pico-pio.conf"
     platform_allow: rpi_pico
+  drivers.spi.pio_spi_dma.loopback:
+    extra_args:
+      - DTC_OVERLAY_FILE="boards/rpi_pico_pio_dma.overlay"
+      - EXTRA_CONF_FILE="overlay-rpi-pico-pio.conf"
+    extra_configs:
+      - CONFIG_SPI_RPI_PICO_PIO_DMA=y
+      - CONFIG_DMA=y
+      - CONFIG_PRINTK=y
+    platform_allow: rpi_pico
   drivers.spi.mcux_flexio_spi.loopback:
     extra_args: DTC_OVERLAY_FILE="overlay-mcux-flexio-spi.overlay"
     filter: CONFIG_DT_HAS_NXP_FLEXIO_ENABLED and