board: rockchip: Add minimal generic RK3576 board

Add a minimal generic RK3576 board that only have eMMC, SDMMC and USB
OTG enabled. This defconfig can be used to boot from eMMC or SD-card on
most RK3576 boards that follow reference board design.

eMMC and SD-card boot tested on:
- ArmSoM CM5
- ArmSoM Sige5
- FriendlyElec NanoPi M5
- Luckfox Omni3576
- Toybrick TB-RK3576D

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

arch/arm/dts/rk3576-generic-u-boot.dtsi

@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+#include "rk3576-u-boot.dtsi"

arch/arm/dts/rk3576-generic.dts

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Minimal generic DT for RK3576 with eMMC, SD-card and USB OTG enabled
+ */
+
+/dts-v1/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include "rk3576.dtsi"
+
+/ {
+	model = "Generic RK3576";
+	compatible = "rockchip,rk3576";
+
+	aliases {
+		mmc0 = &sdhci;
+		mmc1 = &sdmmc;
+	};
+
+	chosen {
+		stdout-path = "serial0:1500000n8";
+	};
+};
+
+&sdhci {
+	bus-width = <8>;
+	cap-mmc-highspeed;
+	mmc-hs200-1_8v;
+	no-sd;
+	no-sdio;
+	non-removable;
+	status = "okay";
+};
+
+&sdmmc {
+	bus-width = <4>;
+	cap-sd-highspeed;
+	disable-wp;
+	no-mmc;
+	no-sdio;
+	status = "okay";
+};
+
+&u2phy0 {
+	status = "okay";
+};
+
+&u2phy0_otg {
+	status = "okay";
+};
+
+&uart0 {
+	pinctrl-0 = <&uart0m0_xfer>;
+	status = "okay";
+};
+
+&usb_drd0_dwc3 {
+	dr_mode = "peripheral";
+	maximum-speed = "high-speed";
+	phys = <&u2phy0_otg>;
+	phy-names = "usb2-phy";
+	status = "okay";
+};

arch/arm/mach-rockchip/rk3576/MAINTAINERS

@@ -0,0 +1,5 @@
+GENERIC-RK3576
+M:	Jonas Karlman <jonas@kwiboo.se>
+S:	Maintained
+F:	arch/arm/dts/rk3576-generic*
+F:	configs/generic-rk3576_defconfig

configs/generic-rk3576_defconfig

@@ -0,0 +1,50 @@
+CONFIG_ARM=y
+CONFIG_SKIP_LOWLEVEL_INIT=y
+CONFIG_COUNTER_FREQUENCY=24000000
+CONFIG_ARCH_ROCKCHIP=y
+CONFIG_DEFAULT_DEVICE_TREE="rk3576-generic"
+CONFIG_ROCKCHIP_RK3576=y
+CONFIG_SYS_LOAD_ADDR=0x40c00800
+CONFIG_DEBUG_UART_BASE=0x2AD40000
+CONFIG_DEBUG_UART_CLOCK=24000000
+CONFIG_DEBUG_UART=y
+# CONFIG_BOOTMETH_VBE is not set
+CONFIG_DEFAULT_FDT_FILE="rockchip/rk3576-generic.dtb"
+# CONFIG_DISPLAY_CPUINFO is not set
+CONFIG_SPL_MAX_SIZE=0x40000
+# CONFIG_SPL_RAW_IMAGE_SUPPORT is not set
+CONFIG_CMD_MEMINFO=y
+CONFIG_CMD_MEMINFO_MAP=y
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_GPT=y
+CONFIG_CMD_MISC=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_ROCKUSB=y
+CONFIG_CMD_USB_MASS_STORAGE=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_RNG=y
+# CONFIG_SPL_DOS_PARTITION is not set
+# CONFIG_OF_UPSTREAM is not set
+CONFIG_OF_SPL_REMOVE_PROPS="clock-names interrupt-parent assigned-clocks assigned-clock-rates assigned-clock-parents"
+CONFIG_NO_NET=y
+# CONFIG_ADC is not set
+# CONFIG_USB_FUNCTION_FASTBOOT is not set
+CONFIG_ROCKCHIP_GPIO=y
+CONFIG_SUPPORT_EMMC_RPMB=y
+CONFIG_MMC_DW=y
+CONFIG_MMC_DW_ROCKCHIP=y
+CONFIG_MMC_SDHCI=y
+CONFIG_MMC_SDHCI_SDMA=y
+CONFIG_MMC_SDHCI_ROCKCHIP=y
+CONFIG_PHY_ROCKCHIP_INNO_USB2=y
+CONFIG_BAUDRATE=1500000
+CONFIG_DEBUG_UART_SHIFT=2
+CONFIG_SYS_NS16550_MEM32=y
+CONFIG_SYSRESET_PSCI=y
+CONFIG_USB=y
+CONFIG_USB_DWC3=y
+CONFIG_USB_DWC3_GENERIC=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_DOWNLOAD=y
+CONFIG_USB_FUNCTION_ROCKUSB=y
+CONFIG_ERRNO_STR=y

doc/board/rockchip/rockchip.rst

@@ -135,6 +135,7 @@ List of mainline supported Rockchip boards:
 
 * rk3576
      - Firefly ROC-RK3576-PC (roc-pc-rk3576)
+     - Generic RK3576 (generic-rk3576)
 
 * rk3588
      - ArmSoM Sige7 (sige7-rk3588)