board: st: stm32h7s78-dk: add support for on-board flash on xspi2

Add device tree entry for the 1Gbit octo-spi flash on the board,
wired to the xspi2 peripheral.

Signed-off-by: Titouan Christophe <[email protected]>

Author: titouanc

boards/st/stm32h7s78_dk/stm32h7s78_dk.dts

@@ -186,6 +186,38 @@
 	status = "okay";
 };
 
+&xspi2 {
+	pinctrl-0 = <&xspim_p2_clk_pn6 &xspim_p2_ncs1_pn1
+		     &xspim_p2_io0_pn2 &xspim_p2_io1_pn3
+		     &xspim_p2_io2_pn4 &xspim_p2_io3_pn5
+		     &xspim_p2_io4_pn8 &xspim_p2_io5_pn9
+		     &xspim_p2_io6_pn10 &xspim_p2_io7_pn11
+		     &xspim_p2_dqs0_pn0>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	mx66uw1g45g: xspi-nor-flash@70000000 {
+		compatible = "st,stm32-xspi-nor";
+		reg = <0x70000000 DT_SIZE_M(128)>; /* 1 Gbits */
+		ospi-max-frequency = <DT_FREQ_M(50)>;
+		spi-bus-width = <XSPI_OCTO_MODE>;
+		data-rate = <XSPI_DTR_TRANSFER>;
+		four-byte-opcodes;
+		status = "okay";
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "nor";
+				reg = <0x00000000 DT_SIZE_M(16)>;
+			};
+		};
+	};
+};
+
 usb2: &usbotg_fs {
 	pinctrl-0 = <&usb_otg_fs_dm_pm12 &usb_otg_fs_dp_pm11>;
 	pinctrl-names = "default";