ARM: at91/dt: sama5d2 Xplained: add QSPI0 + SPI NOR memory nodes

This patch enables the QSPI0 controller, configures its pin muxing and
declares a jedec,spi-nor memory.

sama5d2 Xplained RevB and RevC use the Macronix MX25L25673G flash
memory which advertises a maximum frequency of 80MHz for Quad IO
Fast Read. Set the spi-max-frequency to 80MHz knowing that actually
the QSPI drver will set the SPI bus clock to 166MHz / 3 = 55.3MHz.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[ta:
- port to 5.4,
- add spi-rx/tx-bus-width
- change spi-max-frequency to match the 80MHz limit advertised by
  MX25L25673G for Quad IO Fast Read,
- reword commit message and subject.]
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Author: Cyrille Pitchen

arch/arm/boot/dts/at91-sama5d2_xplained.dts

@@ -72,6 +72,58 @@
 		};
 
 		apb {
+			qspi0: spi@f0020000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_qspi0_default>;
+				status = "disabled"; /* conflict with sdmmc1 */
+
+				flash@0 {
+					#address-cells = <1>;
+					#size-cells = <1>;
+					compatible = "jedec,spi-nor";
+					reg = <0>;
+					spi-max-frequency = <80000000>;
+					spi-tx-bus-width = <4>;
+					spi-rx-bus-width = <4>;
+					m25p,fast-read;
+
+					at91bootstrap@00000000 {
+						label = "at91bootstrap";
+						reg = <0x00000000 0x00040000>;
+					};
+
+					bootloader@00040000 {
+						label = "bootloader";
+						reg = <0x00040000 0x000c0000>;
+					};
+
+					bootloaderenvred@00100000 {
+						label = "bootloader env redundant";
+						reg = <0x00100000 0x00040000>;
+					};
+
+					bootloaderenv@00140000 {
+						label = "bootloader env";
+						reg = <0x00140000 0x00040000>;
+					};
+
+					dtb@00180000 {
+						label = "device tree";
+						reg = <0x00180000 0x00080000>;
+					};
+
+					kernel@00200000 {
+						label = "kernel";
+						reg = <0x00200000 0x00600000>;
+					};
+
+					misc@00800000 {
+						label = "misc";
+						reg = <0x00800000 0x00000000>;
+					};
+				};
+			};
+
 			spi0: spi@f8000000 {
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_spi0_default>;
@@ -535,6 +587,22 @@
 					bias-disable;
 				};
 
+				pinctrl_qspi0_default: qspi0_default {
+					sck_cs {
+						pinmux = <PIN_PA22__QSPI0_SCK>,
+							 <PIN_PA23__QSPI0_CS>;
+						bias-disable;
+					};
+
+					data {
+						pinmux = <PIN_PA24__QSPI0_IO0>,
+							 <PIN_PA25__QSPI0_IO1>,
+							 <PIN_PA26__QSPI0_IO2>,
+							 <PIN_PA27__QSPI0_IO3>;
+						bias-pull-up;
+					};
+				};
+
 				pinctrl_sdmmc0_default: sdmmc0_default {
 					cmd_data {
 						pinmux = <PIN_PA1__SDMMC0_CMD>,