[PATCH 2/2] ARM: dts: samsung: Add Hardkernel ODROID-U2
Henrik Grimler
henrik at grimler.se
Mon Oct 19 07:01:46 PDT 2026
Hi Josef,
Running dt-check-style --mode strict exynos4412-odroidu2.dts with
dt-check-style from
https://github.com/krzk/linux/blob/b4/dts-style-checker-blank-lines/scripts/dtc/dt-check-style
shows a few things that can be improved, commented inline.
On Sun, Oct 18, 2026 at 02:44:59PM +0200, Josef Schlehofer wrote:
> ODROID-U2 is a single board computer from Hardkernel based on the
> Samsung Exynos4412 Prime SoC with 2 GB of LPDDR2 RAM. It is the
> predecessor of the ODROID-U3 and shares most of its design:
> - microSD card slot and eMMC module socket
> - SMSC LAN9730 10/100 Ethernet on HSIC0
> - SMSC USB3503A hub on HSIC1 with two USB 2.0 host ports
> - micro-HDMI port with CEC
> - MAX98090 audio codec with a 3.5 mm headphone jack and an on-board
> digital microphone
> - MAX77686 PMIC
> - 2-pin header for an optional PWM controlled cooling fan
> - blue heartbeat LED
>
> Unlike the ODROID-U3, the micro-USB port has no VBUS supply switch, so
> it can only work in peripheral mode, and there is no expansion header
> with SPI. The 3.5 mm jack is headphone only and the speaker outputs of
> the codec are not connected.
I compared your linked schematics with the ones for odroid-u3 and
agree that this seems to be all the differences.
> Add an initial device tree for the board, based on the ODROID-U3 one,
> and update the comments in the common dtsi, as the LDO22 and BUCK8
> constraints are now also set by the ODROID-U2.
>
> Also route "HiFi Capture" to "Mixer DAI RX", as on the ODROID-XU3. The
> odroid sound card driver adds only the playback routes for boards with
> a single CPU DAI, so without it the DPCM capture path to the I2S
> back-end is incomplete and recording from the digital microphone fails
> with "no backend DAIs enabled for Primary".
>
> Link: https://www.hardkernel.com/shop/odroid-u2/
> Link: https://www.hardkernel.com/blog-2/odroid-u2-u-schematics/
> Signed-off-by: Josef Schlehofer <pepe.schlehofer at gmail.com>
> ---
> arch/arm/boot/dts/samsung/Makefile | 1 +
> .../dts/samsung/exynos4412-odroid-common.dtsi | 6 +-
> .../boot/dts/samsung/exynos4412-odroidu2.dts | 139 ++++++++++++++++++
> 3 files changed, 143 insertions(+), 3 deletions(-)
> create mode 100644 arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts
>
> diff --git a/arch/arm/boot/dts/samsung/Makefile b/arch/arm/boot/dts/samsung/Makefile
> index e0143ee8c82d..2a173e4b3e1a 100644
> --- a/arch/arm/boot/dts/samsung/Makefile
> +++ b/arch/arm/boot/dts/samsung/Makefile
> @@ -16,6 +16,7 @@ dtb-$(CONFIG_ARCH_EXYNOS4) += \
> exynos4412-i9305.dtb \
> exynos4412-itop-elite.dtb \
> exynos4412-n710x.dtb \
> + exynos4412-odroidu2.dtb \
> exynos4412-odroidu3.dtb \
> exynos4412-odroidx.dtb \
> exynos4412-odroidx2.dtb \
> diff --git a/arch/arm/boot/dts/samsung/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/samsung/exynos4412-odroid-common.dtsi
> index 93ddbd4b0a18..b56b92c78c1d 100644
> --- a/arch/arm/boot/dts/samsung/exynos4412-odroid-common.dtsi
> +++ b/arch/arm/boot/dts/samsung/exynos4412-odroid-common.dtsi
> @@ -414,8 +414,8 @@ ldo21_reg: LDO21 {
>
> ldo22_reg: LDO22 {
> /*
> - * Only U3 uses it, so let it define the
> - * constraints
> + * Only U2 and U3 use it, so let them define
> + * the constraints
> */
> regulator-name = "LDO22";
> regulator-boot-on;
> @@ -486,7 +486,7 @@ buck7_reg: BUCK7 {
> buck8_reg: BUCK8 {
> /*
> * Constraints set by specific board: X,
> - * X2 and U3.
> + * X2, U2 and U3.
> */
> regulator-name = "BUCK8_2.8V";
> };
> diff --git a/arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts b/arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts
> new file mode 100644
> index 000000000000..5cb5f874b562
> --- /dev/null
> +++ b/arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Hardkernel's Exynos4412 based ODROID-U2 board device tree source
> + *
> + * Copyright (c) 2014 Marek Szyprowski <m.szyprowski at samsung.com>
> + * Copyright (c) 2026 Josef Schlehofer <pepe.schlehofer at gmail.com>
> + *
> + * Device tree source file for Hardkernel's ODROID-U2 board which is based
> + * on Samsung's Exynos4412 SoC.
> + */
> +
> +/dts-v1/;
> +#include <dt-bindings/leds/common.h>
> +#include "exynos4412-odroid-common.dtsi"
> +#include "exynos4412-prime.dtsi"
> +
> +/ {
> + model = "Hardkernel ODROID-U2 board based on Exynos4412";
> + compatible = "hardkernel,odroid-u2", "samsung,exynos4412", "samsung,exynos4";
> +
> + aliases {
> + ethernet = ðernet;
> + };
> +
> + memory at 40000000 {
> + device_type = "memory";
> + reg = <0x40000000 0x7ff00000>;
> + };
Please move below leds {} so that the nodes are sorted alphabetically.
> +
> + leds {
> + compatible = "gpio-leds";
> +
> + led1 {
> + function = LED_FUNCTION_HEARTBEAT;
> + color = <LED_COLOR_ID_BLUE>;
> + gpios = <&gpc1 0 GPIO_ACTIVE_LOW>;
> + default-state = "on";
> + linux,default-trigger = "heartbeat";
> + };
> + };
> +
> + fan0: pwm-fan {
> + compatible = "pwm-fan";
> + pwms = <&pwm 0 10000 0>;
> + #cooling-cells = <2>;
> + cooling-levels = <0 102 170 230>;
> + };
> +};
> +
> +&adc {
> + vdd-supply = <&ldo10_reg>;
> + /* Nothing connected to ADC inputs, keep it disabled */
> +};
> +
> +/* Supply for LAN9730/SMSC95xx */
> +&buck8_reg {
> + regulator-name = "BUCK8_P3V3";
> + regulator-min-microvolt = <3300000>;
> + regulator-max-microvolt = <3300000>;
> +};
> +
> +&cpu_thermal {
> + cooling-maps {
> + map0 {
> + trip = <&cpu_alert1>;
> + cooling-device = <&cpu0 9 9>, <&cpu1 9 9>,
> + <&cpu2 9 9>, <&cpu3 9 9>,
> + <&fan0 1 2>;
> + };
Newline here between child nodes please.
> + map1 {
> + trip = <&cpu_alert2>;
> + cooling-device = <&cpu0 15 15>, <&cpu1 15 15>,
> + <&cpu2 15 15>, <&cpu3 15 15>,
> + <&fan0 2 3>;
> + };
Newline here between child nodes please.
> + map2 {
> + trip = <&cpu_alert0>;
> + cooling-device = <&fan0 0 1>;
> + };
> + };
> +};
> +
> +&ehci {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + phys = <&exynos_usbphy 2>, <&exynos_usbphy 3>;
> + phy-names = "hsic0", "hsic1";
> +
> + ethernet: ethernet at 2 {
> + compatible = "usb424,9730";
> + reg = <2>;
> + local-mac-address = [00 00 00 00 00 00]; /* Filled in by a bootloader */
> + };
> +};
> +
> +&hdmicec {
> + needs-hpd;
> +};
> +
> +/* No VBUS supply switch on the micro-USB port */
> +&hsotg {
> + dr_mode = "peripheral";
> +};
> +
> +/* VDDQ for MSHC (eMMC card) */
> +&ldo22_reg {
> + regulator-name = "LDO22_VDDQ_MMC4_2.8V";
> + regulator-min-microvolt = <2800000>;
> + regulator-max-microvolt = <2800000>;
> +};
> +
> +&mshc_0 {
> + vqmmc-supply = <&ldo22_reg>;
> +};
> +
> +&pwm {
> + pinctrl-0 = <&pwm0_out>;
> + pinctrl-names = "default";
> + samsung,pwm-outputs = <0>;
> + status = "okay";
Empty line before status please.
> +};
> +
> +&sound {
> + model = "Odroid-U2";
> + samsung,audio-widgets =
> + "Headphone", "Headphone Jack",
> + "Microphone", "DMIC";
Please sort samsung,audio-widgets after audio-routing (vendor prefixed
properties last).
> + audio-routing = "Headphone Jack", "HPL",
> + "Headphone Jack", "HPR",
> + "DMICL", "DMIC",
> + "DMICR", "DMIC",
> + "Mixer DAI RX", "HiFi Capture";
> +};
> +
> +&usb3503 {
> + clock-names = "refclk";
Please sort clock-names after clocks.
> + clocks = <&pmu_system_controller 0>;
> + refclk-frequency = <24000000>;
> +};
> --
> 2.54.0 (Apple Git-157)
>
>
Best regards
Henrik Grimler
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