[PATCH 4/6] riscv: dts: spacemit: enable QSPI and add SPI NOR on Milk-V Jupiter

[Aurelien Jarno <aurelien@aurel32.net>]

Add the QSPI controller node for the Milk-V Jupiter board and describe
the attached SPI NOR flash (GD25Q64E).

The flash supports a frequency up to 133MHz (80 MHz for reads), and the
SoC supports a frequency up to 104 MHz. However tests have shown that
the flash is not reliably detected above 26.5 MHz, consistent with
frequency used in the vendor kernel. Therefore, use this frequency.

The m25p,fast-read properties is taken from the vendor kernel.

Add a corresponding flash partition layout, matching the layout and the
names used in the vendor U-Boot.

Also add the bootph-pre-ram property to make the device tree usable by
early firmware/bootloaders without modification, as U-Boot is stored on
this NOR flash.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 .../boot/dts/spacemit/k1-milkv-jupiter.dts    | 44 ++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
index 836311c3f035c..05ab5df50be51 100644
--- a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
@@ -173,7 +173,7 @@ buck3_1v8: buck3 {
 				regulator-always-on;
 			};
 
-			buck4 {
+			buck4_3v3: buck4 {
 				regulator-min-microvolt = <500000>;
 				regulator-max-microvolt = <3300000>;
 				regulator-ramp-delay = <5000>;
@@ -256,6 +256,48 @@ dldo7 {
 	};
 };
 
+&qspi {
+	pinctrl-names = "default";
+	pinctrl-0 = <&qspi_cfg>;
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <26500000>;
+		spi-rx-bus-width = <4>;
+		spi-tx-bus-width = <4>;
+		vcc-supply = <&buck4_3v3>; /* QSPI_VCC1833 */
+		m25p,fast-read;
+		bootph-pre-ram;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			bootinfo@0 {
+				reg = <0x0 0x10000>;
+			};
+			private@10000 {
+				reg = <0x10000 0x10000>;
+			};
+			fsbl@20000 {
+				reg = <0x20000 0x40000>;
+			};
+			env@60000 {
+				reg = <0x60000 0x10000>;
+			};
+			opensbi@70000 {
+				reg = <0x70000 0x30000>;
+			};
+			uboot@a00000 {
+				reg = <0xa0000 0x760000>;
+			};
+		};
+	};
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_2_cfg>;
-- 
2.51.0