From 3163b4525121fd36e44490db1df33121e1ab48d6 Mon Sep 17 00:00:00 2001
From: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
Date: Wed, 4 Nov 2020 00:06:26 +0100
Subject: [PATCH 02/10] ARM: dts: exynos: Add reboot modes to midas

The values have been taken from the sec-reboot.c driver in
the 3.0.101 smdk4412 kernel used in LineageOS which is based
on Samsung source code releases for various devices.

Only the strict minimum modes have been added: the S-Boot 4.0
bootloader is nonfree, so exporting less well known modes could
potentially have unwanted consequences.

TODO:
- After reboot to download, heimdall doesn't work while it works
  with the SMDK4412 kernel.
- Fix reboot without arguments (Test: Try "Reboot system now"
  in a recovery after rebooting to the recovery)

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 arch/arm/boot/dts/exynos4412-midas.dtsi | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/exynos4412-midas.dtsi b/arch/arm/boot/dts/exynos4412-midas.dtsi
index 968c7943653e..159fd1e21339 100644
--- a/arch/arm/boot/dts/exynos4412-midas.dtsi
+++ b/arch/arm/boot/dts/exynos4412-midas.dtsi
@@ -981,6 +981,29 @@ &mshc_0 {
 &pmu_system_controller {
 	assigned-clocks = <&pmu_system_controller 0>;
 	assigned-clock-parents =  <&clock CLK_XUSBXTI>;
+
+	/* S-Boot 4.0 */
+	#define S5P_INFORM2		0xF008
+	#define S5P_INFORM3		0x080C
+	#define BOOT_MODE_PREFIX	0x12345670
+	#define BOOT_NORMAL		(BOOT_MODE_PREFIX | 0)
+	#define BOOT_DOWNLOAD		(BOOT_MODE_PREFIX | 1)
+	#define BOOT_RECOVERY		(BOOT_MODE_PREFIX | 4)
+
+	no-lpm-mode {
+		compatible = "syscon-reboot";
+		offset = <S5P_INFORM2>;
+		value = <0x12345678>;
+	};
+
+	reboot-mode {
+		compatible = "syscon-reboot-mode";
+		offset = <S5P_INFORM3>;
+		mode-normal = <BOOT_NORMAL>;
+		mode-recovery = <BOOT_RECOVERY>;
+		mode-bootloader = <BOOT_DOWNLOAD>;
+		mode-download = <BOOT_DOWNLOAD>;
+	};
 };
 
 &pinctrl_0 {
-- 
2.33.0