[PATCH v2] arm64: dts: pinephone: Add pstore support for PinePhone A64

[Andrey Skvortsov <andrej.skvortzov@gmail.com>]

This patch reserves some memory in the DTS and sets up a
pstore device tree node to enable pstore support.

In general any DRAM address, that isn't overwritten during a boot is
suitable for pstore.

Range from 0x40000000 - 0x50000000 is heavily used by u-boot for
internal use and to load kernel, fdt, fdto, scripts, pxefile and ramdisk
later in the boot process. Ramdisk start address is 0x4FF00000,
initramfs for kernel with some hacking features and debug info enabled
can take more than 100Mb and final address will be around 0x58000000.
Address 0x61000000 will most likely not overlap with that.

Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
---

Changes in v2:
 - Update commit description with information about why this base address is used.

 .../boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
index 87847116ab6d..84f9410b0b70 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
@@ -19,6 +19,22 @@ aliases {
 		serial0 = &uart0;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		pstore_mem: ramoops@61000000 {
+			compatible = "ramoops";
+			reg = <0x61000000 0x100000>;
+			record-size = <0x20000>;
+			console-size = <0x20000>;
+			ftrace-size = <0x20000>;
+			pmsg-size = <0x20000>;
+			ecc-size = <16>;
+		};
+	};
+
 	backlight: backlight {
 		compatible = "pwm-backlight";
 		pwms = <&r_pwm 0 50000 PWM_POLARITY_INVERTED>;
-- 
2.40.1