[PATCH] rockchip: rk3308-rock-s0: Fix SD-card boot on v1.1 hw revision

[Jonas Karlman]

BootROM leave GPIO4_D6 configured as SDMMC_PWREN function and DW MMC
driver set PWREN high in dwmci_init().

However, HW revision prior to v1.2 must pull GPIO4_D6 low to access
sdmmc. For HW revision v1.2 the state of GPIO4_D6 has no impact.

Upstream linux-rockchip maintainer tree has merged a patch "arm64: dts:
rockchip: Fix sdmmc access on rk3308-rock-s0 v1.1 boards" for v6.14 to
fix this issue.

Add the upstream vmmc-supply regulator in board u-boot.dtsi and enable
required Kconfig options to set GPIO4_D6 low to fix reading sdmmc on
v1.1 hw revision.

The regulator-3v3-vcc-sd and sdmmc-2030 nodes along with the vmmc-supply
prop can be dropped once dts/upstream sync v6.14 DTs.

Fixes: 25438c40a007 ("board: rockchip: Add Radxa ROCK S0")
Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
---
 arch/arm/dts/rk3308-rock-s0-u-boot.dtsi | 43 +++++++++++++++++++++++++
 configs/rock-s0-rk3308_defconfig        |  2 ++
 2 files changed, 45 insertions(+)

diff --git a/arch/arm/dts/rk3308-rock-s0-u-boot.dtsi b/arch/arm/dts/rk3308-rock-s0-u-boot.dtsi
index dd4cb8660b8d..3b849280c4ad 100644
--- a/arch/arm/dts/rk3308-rock-s0-u-boot.dtsi
+++ b/arch/arm/dts/rk3308-rock-s0-u-boot.dtsi
@@ -2,11 +2,50 @@
 
 #include "rk3308-u-boot.dtsi"
 
+/ {
+	/*
+	 * HW revision prior to v1.2 must pull GPIO4_D6 low to access sdmmc.
+	 * This is modeled as an always-on active low fixed regulator.
+	 */
+	vcc_sd: regulator-3v3-vcc-sd {
+		compatible = "regulator-fixed";
+		gpios = <&gpio4 RK_PD6 GPIO_ACTIVE_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&sdmmc_2030>;
+		regulator-name = "vcc_sd";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		vin-supply = <&vcc_io>;
+	};
+};
+
 &emmc_pwren {
 	bootph-pre-ram;
 	bootph-some-ram;
 };
 
+&gpio4 {
+	bootph-pre-ram;
+};
+
+&pinctrl {
+	sdmmc {
+		sdmmc_2030: sdmmc-2030 {
+			rockchip,pins = <4 RK_PD6 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+};
+
+&sdmmc {
+	vmmc-supply = <&vcc_sd>;
+};
+
+&sdmmc_2030 {
+	bootph-pre-ram;
+};
+
 &uart0 {
 	bootph-all;
 	clock-frequency = <24000000>;
@@ -17,6 +56,10 @@
 	bootph-pre-ram;
 };
 
+&vcc_sd {
+	bootph-pre-ram;
+};
+
 &vdd_core {
 	regulator-init-microvolt = <1015000>;
 };
diff --git a/configs/rock-s0-rk3308_defconfig b/configs/rock-s0-rk3308_defconfig
index 0a46e7bb1871..063e0b921d73 100644
--- a/configs/rock-s0-rk3308_defconfig
+++ b/configs/rock-s0-rk3308_defconfig
@@ -2,6 +2,7 @@ CONFIG_ARM=y
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_COUNTER_FREQUENCY=24000000
 CONFIG_ARCH_ROCKCHIP=y
+CONFIG_SPL_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="rockchip/rk3308-rock-s0"
 CONFIG_DM_RESET=y
 CONFIG_ROCKCHIP_RK3308=y
@@ -53,6 +54,7 @@ CONFIG_PHY_ROCKCHIP_INNO_USB2=y
 CONFIG_PINCTRL=y
 CONFIG_REGULATOR_PWM=y
 CONFIG_DM_REGULATOR_FIXED=y
+CONFIG_SPL_DM_REGULATOR_FIXED=y
 CONFIG_PWM_ROCKCHIP=y
 CONFIG_RAM=y
 CONFIG_BAUDRATE=1500000
-- 
2.47.1