boards: nxp: frdm_mcxn947: add support for USDHC0

Add support for USDHC0 controller on FRDM_MCXN947 board. This support
was verified using the `tests/subsys/sd/sdmmc` and
`tests/subsys/sd/sdio` testcases. Note that this board does not ship
with the SD header (J12) populated by default, so the user must populate
one.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>

boards/nxp/frdm_mcxn947/Kconfig.defconfig

@@ -6,4 +6,12 @@ if BOARD_FRDM_MCXN947
 config NET_L2_ETHERNET
 	default y if NETWORKING
 
+if SD_STACK
+
+# SD stack requires larger main stack size
+config MAIN_STACK_SIZE
+	default 1536
+
+endif
+
 endif

boards/nxp/frdm_mcxn947/board.c

@@ -192,6 +192,11 @@ static int frdm_mcxn947_init(void)
 	CLOCK_AttachClk(kPLL0_to_CTIMER4);
 #endif
 
+#if DT_NODE_HAS_STATUS(DT_NODELABEL(usdhc0), okay)
+	CLOCK_SetClkDiv(kCLOCK_DivUSdhcClk, 1u);
+	CLOCK_AttachClk(kFRO_HF_to_USDHC);
+#endif
+
 #if CONFIG_FLASH_MCUX_FLEXSPI_NOR
 	/* We downclock the FlexSPI to 50MHz, it will be set to the
 	 * optimum speed supported by the Flash device during FLEXSPI

boards/nxp/frdm_mcxn947/doc/index.rst

@@ -82,6 +82,8 @@ The FRDM-MCXN947 board configuration supports the following hardware features:
 +-----------+------------+-------------------------------------+
 | CTIMER    | on-chip    | counter                             |
 +-----------+------------+-------------------------------------+
+| USDHC     | on-chip    | sdhc                                |
++-----------+------------+-------------------------------------+
 
 Targets available
 ==================

boards/nxp/frdm_mcxn947/frdm_mcxn947-pinctrl.dtsi

@@ -129,4 +129,23 @@
 		};
 	};
 
+	pinmux_usdhc0: pinmux_usdhc0 {
+		group0 {
+			pinmux = <SDHC0_CMD_PIO2_5>,
+			       <SDHC0_D0_PIO2_3>,
+			       <SDHC0_D1_PIO2_2>,
+			       <SDHC0_D2_PIO2_7>,
+			       <SDHC0_D3_PIO2_6>;
+			slew-rate = "fast";
+			drive-strength = "low";
+			bias-pull-up;
+			input-enable;
+		};
+		group1 {
+			pinmux = <SDHC0_CLK_PIO2_4>;
+			slew-rate = "fast";
+			drive-strength = "low";
+			input-enable;
+		};
+	};
 };

boards/nxp/frdm_mcxn947/frdm_mcxn947.dtsi

@@ -14,6 +14,7 @@
 		led2 = &blue_led;
 		sw0 = &user_button_2;
 		sw1 = &user_button_3;
+		sdhc0 = &usdhc0;
 	};
 
 	leds {
@@ -173,3 +174,12 @@
 	pinctrl-0 = <&pinmux_flexpwm1_pwm0>;
 	pinctrl-names = "default";
 };
+
+&usdhc0 {
+	pinctrl-0 = <&pinmux_usdhc0>;
+	pinctrl-1 = <&pinmux_usdhc0>;
+	pinctrl-2 = <&pinmux_usdhc0>;
+	cd-gpios = <&gpio2 1 GPIO_ACTIVE_LOW>;
+	pinctrl-names = "default", "slow", "med";
+	no-1-8-v;
+};

boards/nxp/frdm_mcxn947/frdm_mcxn947_mcxn947_cpu0.dts

@@ -58,6 +58,10 @@
 	status = "okay";
 };
 
+&gpio2 {
+	status = "okay";
+};
+
 &green_led {
 	status = "okay";
 };
@@ -141,3 +145,11 @@
 &ctimer0 {
 	status = "okay";
 };
+
+&usdhc0 {
+	status = "okay";
+	sdmmc {
+		compatible = "zephyr,sdmmc-disk";
+		status = "okay";
+	};
+};

boards/nxp/frdm_mcxn947/frdm_mcxn947_mcxn947_cpu0.yaml

@@ -23,4 +23,5 @@ supported:
   - watchdog
   - pwm
   - counter
+  - sdhc
 vendor: nxp