[PATCH 1/4] rockchip: rk3399-roc-pc: Hook sysreset gpio to enable full reset

[Paul Kocialkowski]

From: Paul Kocialkowski <contact at paulk.fr>

The reset mechanism used by Linux to reset the SoC is known to only
partially reset the logic. A mechanism is implemented in
rk3399_force_power_on_reset to use a GPIO connected to the PMIC's
over-temperature (OTP) reset pin, which fully resets all logic.

Hook the associated GPIO where the function expects it to enable this
reset mechanism and avoid any possible side-effect of partially-reset
units.

Without this patch, reading from the micro sd slot fails after a reset.
With this mechanism, U-Boot is able to boot from it reliably.

Signed-off-by: Paul Kocialkowski <contact at paulk.fr>
---
 arch/arm/dts/rk3399-roc-pc-u-boot.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/dts/rk3399-roc-pc-u-boot.dtsi b/arch/arm/dts/rk3399-roc-pc-u-boot.dtsi
index aecf7dbe383c..883d399a06a3 100644
--- a/arch/arm/dts/rk3399-roc-pc-u-boot.dtsi
+++ b/arch/arm/dts/rk3399-roc-pc-u-boot.dtsi
@@ -7,6 +7,10 @@
 #include "rk3399-sdram-lpddr4-100.dtsi"
 
 / {
+	config {
+		sysreset-gpio = <&gpio1 RK_PA6 GPIO_ACTIVE_HIGH>;
+	};
+
 	vcc_hub_en: vcc_hub_en-regulator {
 		compatible = "regulator-fixed";
 		enable-active-high;
@@ -36,6 +40,10 @@
 	bootph-pre-ram;
 };
 
+&gpio1 {
+	bootph-pre-ram;
+};
+
 &spi1 {
 	flash at 0 {
 		bootph-pre-ram;
-- 
2.46.2