[PATCH v3 1/2] ARM: dts: aspeed: add an alt 128M flash layout

[Marc Olberding <molberding@nvidia.com>]

Add a 128M layout for the BMC flash chip we didn't boot from. Including
this allows the user to write to each partition on the alternate spi
chip. This dtsi follows the existing standard of using the same layout
as non alt version and prepending `alt` to each partition's name.

Tested by running on target and catting sysfs nodes
    for devdir in /sys/class/mtd/mtd*; do
         [[ -d $devdir && -r $devdir/name ]] || continue
         name=$(<"$devdir/name")
         [[ $name == alt* ]] || continue

         size=$(<"$devdir/size")
         offset=0
         [[ -r $devdir/offset ]] && offset=$(<"$devdir/offset")

         dev=$(basename "$devdir")
         printf "%s name=%s offset=0x%X size=0x%X\n" "$dev" "$name" \
            "$offset" "$size"
    done

    mtd10 name=alt-rofs offset=0xA00000 size=0x5600000
    mtd11 name=alt-rwfs offset=0x6000000 size=0x2000000
    mtd7 name=alt-u-boot offset=0x0 size=0xE0000
    mtd8 name=alt-u-boot-env offset=0xE0000 size=0x20000
    mtd9 name=alt-kernel offset=0x100000 size=0x900000

Ran dtbs check, no errors from the msx4 dts

running diff between the main and alt flash layouts shows that the only
diff is alt prepended to the partition labels, as expected.

Signed-off-by: Marc Olberding <molberding@nvidia.com>
---
 .../dts/aspeed/openbmc-flash-layout-128-alt.dtsi   | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi b/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi
new file mode 100644
index 000000000000..08ce2eab472c
--- /dev/null
+++ b/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+partitions {
+	compatible = "fixed-partitions";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	u-boot@0 {
+		reg = <0x0 0xe0000>; // 896KB
+		label = "alt-u-boot";
+	};
+
+	u-boot-env@e0000 {
+		reg = <0xe0000 0x20000>; // 128KB
+		label = "alt-u-boot-env";
+	};
+
+	kernel@100000 {
+		reg = <0x100000 0x900000>; // 9MB
+		label = "alt-kernel";
+	};
+
+	rofs@a00000 {
+		reg = <0xa00000 0x5600000>; // 86MB
+		label = "alt-rofs";
+	};
+
+	rwfs@6000000 {
+		reg = <0x6000000 0x2000000>; // 32MB
+		label = "alt-rwfs";
+	};
+};

-- 
2.34.1