[PATCH v9 2/2] ARM: dts: aspeed: Add ASRock Rack B650D4U BMC

[Prasanth Kumar Padarthi <prasanth.padarthi10@gmail.com>]

Add the device tree for the ASRock Rack B650D4U BMC, based on the
ASPEED AST2600 SoC.

Describe memory, SPI NOR partitions, the UART console, GPIO line
names, framebuffer memory, and the EEPROM on I2C7. Use the EEPROM
as the NVMEM provider for the MAC0 address and configure MAC0 with
an RTL8211F PHY in RGMII-ID mode.

Enable both ADC engines with 2.5 V internal references and their
pin groups. Expose the sixteen channels through an IIO-to-hwmon
bridge for board voltage monitoring.

The DTB compiles with aspeed_g5_defconfig. Binding validation with
dtschema 2026.9 completes without diagnostics. Board validation
reports unmatched schemas for inherited AST2600 LHC and I3C-global
nodes, with no board-specific errors in the reported output.

ADC readings and recovery after BMC restart were tested using the
same ADC configuration in a locally patched OpenBMC image. That
image uses a different flash layout and separate power-control
changes; this complete upstream DTS has not been boot-tested.

Reviewed-by: Andrew Lunn <andrew@lunn.ch> # MAC0 and MDIO nodes only
Signed-off-by: Prasanth Kumar Padarthi <prasanth.padarthi10@gmail.com>
---
 arch/arm/boot/dts/aspeed/Makefile             |   1 +
 .../dts/aspeed/aspeed-bmc-asrock-b650d4u.dts  | 173 ++++++++++++++++++
 2 files changed, 174 insertions(+)
 create mode 100644 arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-b650d4u.dts

diff --git a/arch/arm/boot/dts/aspeed/Makefile b/arch/arm/boot/dts/aspeed/Makefile
index 6874b621d..fcb94e62c 100644
--- a/arch/arm/boot/dts/aspeed/Makefile
+++ b/arch/arm/boot/dts/aspeed/Makefile
@@ -10,6 +10,7 @@ dtb-$(CONFIG_ARCH_ASPEED) += \
 	aspeed-bmc-ampere-mtmitchell.dtb \
 	aspeed-bmc-arm-stardragon4800-rep2.dtb \
 	aspeed-bmc-asrock-altrad8.dtb \
+	aspeed-bmc-asrock-b650d4u.dtb \
 	aspeed-bmc-asrock-e3c246d4i.dtb \
 	aspeed-bmc-asrock-e3c256d4i.dtb \
 	aspeed-bmc-asrock-paul-ipmi-card.dtb \
diff --git a/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-b650d4u.dts b/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-b650d4u.dts
new file mode 100644
index 000000000..630588dcb
--- /dev/null
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-b650d4u.dts
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "aspeed-g6.dtsi"
+
+/ {
+	compatible = "asrock,b650d4u-bmc", "aspeed,ast2600";
+	model = "ASRock Rack B650D4U BMC";
+
+	aliases {
+		serial0 = &uart5;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory@80000000 {
+		device_type = "memory";
+		reg = <0x80000000 0x20000000>;
+	};
+
+	reserved-memory {
+		ranges;
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		gfx_memory: framebuffer {
+			compatible = "shared-dma-pool";
+			alignment = <0x01000000>;
+			reusable;
+			size = <0x01000000>;
+		};
+	};
+};
+
+&fmc {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		label = "bmc";
+		spi-max-frequency = <50000000>;
+		spi-rx-bus-width = <4>;
+		m25p,fast-read;
+
+		status = "okay";
+
+#include "openbmc-flash-layout-64.dtsi"
+	};
+};
+
+&gfx {
+	memory-region = <&gfx_memory>;
+
+	status = "okay";
+};
+
+&gpio0 {
+	gpio-line-names =
+		/* A0-A7 */     "", "", "", "", "", "", "", "",
+		/* B0-B7 */     "", "", "", "", "", "", "", "",
+		/* C0-C7 */     "", "", "", "", "", "", "", "",
+		/* D0-D7 */     "", "", "", "", "", "", "", "",
+		/* E0-E7 */     "", "", "", "", "", "", "", "",
+		/* F0-F7 */     "", "", "", "", "", "", "", "",
+		/* G0-G7 */     "", "", "", "", "", "", "", "",
+		/* H0-H7 */     "", "", "", "", "", "", "", "",
+		/* I0-I7 */     "", "", "", "", "", "", "", "",
+		/* J0-J7 */     "", "", "", "", "", "", "", "",
+		/* K0-K7 */     "", "", "", "", "", "", "", "",
+		/* L0-L7 */     "", "", "", "", "", "", "", "",
+		/* M0-M7 */     "", "", "", "", "", "", "", "",
+		/* N0-N7 */     "", "", "", "", "", "", "", "",
+		/* O0-O7 */     "", "", "", "", "", "", "", "",
+		/* P0-P7 */     "button-reset-n", "control-reset-n",
+		"button-power-n", "control-power-n",
+		"button-nmi-n", "control-nmi-n",
+		"", "",
+		/* Q0-Q7 */     "", "", "", "", "", "", "", "",
+		/* R0-R7 */     "", "", "", "", "", "", "", "",
+		/* S0-S7 */     "", "", "", "", "", "", "", "",
+		/* T0-T7 */     "", "", "", "", "", "", "", "",
+		/* U0-U7 */     "", "", "", "", "", "", "", "",
+		/* V0-V7 */     "", "", "", "", "", "", "", "",
+		/* W0-W7 */     "", "", "", "", "", "", "", "",
+		/* X0-X7 */     "", "", "", "", "", "", "", "",
+		/* Y0-Y7 */     "", "", "", "", "", "", "", "",
+		/* Z0-Z7 */     "", "", "", "", "", "", "", "";
+};
+
+&i2c7 {
+	status = "okay";
+
+	eeprom@57 {
+		compatible = "atmel,24c128";
+		reg = <0x57>;
+		pagesize = <16>;
+
+		nvmem-layout {
+			compatible = "fixed-layout";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			eth0_macaddress: macaddress@3f80 {
+				reg = <0x3f80 6>;
+			};
+		};
+	};
+};
+
+&mac0 {
+	nvmem-cells = <&eth0_macaddress>;
+	nvmem-cell-names = "mac-address";
+	phy-handle = <&ethphy0>;
+	phy-mode = "rgmii-id";
+	pinctrl-0 = <&pinctrl_rgmii1_default>;
+	pinctrl-names = "default";
+
+	status = "okay";
+};
+
+&mdio0 {
+	status = "okay";
+
+	ethphy0: ethernet-phy@0 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <0>;
+	};
+};
+
+&uart5 {
+	status = "okay";
+};
+
+/ {
+	iio-hwmon {
+		compatible = "iio-hwmon";
+		io-channels = <&adc0 0>, <&adc0 1>, <&adc0 2>, <&adc0 3>,
+			      <&adc0 4>, <&adc0 5>, <&adc0 6>, <&adc0 7>,
+			      <&adc1 0>, <&adc1 1>, <&adc1 2>, <&adc1 3>,
+			      <&adc1 4>, <&adc1 5>, <&adc1 6>, <&adc1 7>;
+	};
+};
+
+&adc0 {
+	status = "okay";
+	aspeed,int-vref-microvolt = <2500000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_adc0_default>,
+		    <&pinctrl_adc1_default>,
+		    <&pinctrl_adc2_default>,
+		    <&pinctrl_adc3_default>,
+		    <&pinctrl_adc4_default>,
+		    <&pinctrl_adc5_default>,
+		    <&pinctrl_adc6_default>,
+		    <&pinctrl_adc7_default>;
+};
+
+&adc1 {
+	status = "okay";
+	aspeed,int-vref-microvolt = <2500000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_adc8_default>,
+		    <&pinctrl_adc9_default>,
+		    <&pinctrl_adc10_default>,
+		    <&pinctrl_adc11_default>,
+		    <&pinctrl_adc12_default>,
+		    <&pinctrl_adc13_default>,
+		    <&pinctrl_adc14_default>,
+		    <&pinctrl_adc15_default>;
+};
-- 
2.47.3