From 2269217bbddb3d729f6129dceda8da5b1c73ba05 Mon Sep 17 00:00:00 2001
From: Sam Protsenko <semen.protsenko@linaro.org>
Date: Tue, 23 Jul 2024 13:14:39 -0500
Subject: [PATCH] arm: exynos: Enable TRNG on E850-96 board

Enable True Random Number Generator (TRNG) on E850-96 board. To do so:
  1. Enable DM_RNG and RNG_EXYNOS for TARGET_E850_96
  2. Add TRNG node to E850-96 device tree
  3. Enable 'rng' command support for easy TRNG testing

TRNG node is already applied in Linux kernel device tree, but it hasn't
appeared in upstream dts yet. Add it in U-Boot override dtsi file
temporarily; it can be removed once it appears in upstream dts.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
---
 arch/arm/dts/exynos850-e850-96-u-boot.dtsi | 11 +++++++++++
 arch/arm/mach-exynos/Kconfig               |  2 ++
 configs/e850-96_defconfig                  |  1 +
 3 files changed, 14 insertions(+)

diff --git a/arch/arm/dts/exynos850-e850-96-u-boot.dtsi b/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
index 6d7148f726..3aa5d8bb10 100644
--- a/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
+++ b/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
@@ -3,6 +3,17 @@
  * Copyright (c) 2023 Linaro Ltd.
  */
 
+&soc {
+	/* TODO: Remove this node once it appears in upstream dts */
+	trng: rng@12081400 {
+		compatible = "samsung,exynos850-trng";
+		reg = <0x12081400 0x100>;
+		clocks = <&cmu_core CLK_GOUT_SSS_ACLK>,
+			 <&cmu_core CLK_GOUT_SSS_PCLK>;
+		clock-names = "secss", "pclk";
+	};
+};
+
 &pmu_system_controller {
 	bootph-all;
 	samsung,uart-debug-1;
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index cad8bb044c..3fee5a4299 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -250,6 +250,8 @@ config TARGET_E850_96
 	select PINCTRL
 	select PINCTRL_EXYNOS850
 	imply OF_UPSTREAM
+	imply DM_RNG
+	imply RNG_EXYNOS
 
 endchoice
 endif
diff --git a/configs/e850-96_defconfig b/configs/e850-96_defconfig
index 38b9968c16..2949da2426 100644
--- a/configs/e850-96_defconfig
+++ b/configs/e850-96_defconfig
@@ -11,6 +11,7 @@ CONFIG_DEFAULT_DEVICE_TREE="exynos/exynos850-e850-96"
 CONFIG_SYS_LOAD_ADDR=0x80000000
 # CONFIG_AUTOBOOT is not set
 # CONFIG_DISPLAY_CPUINFO is not set
+CONFIG_CMD_RNG=y
 # CONFIG_NET is not set
 CONFIG_CLK_EXYNOS850=y
 # CONFIG_MMC is not set
-- 
2.39.5