[PATCH v2 0/2] ARM: dts: samsung: Add support for Hardkernel ODROID-U2

[PATCH v2 0/2] ARM: dts: samsung: Add support for Hardkernel ODROID-U2

[Josef Schlehofer]

This series adds the Hardkernel ODROID-U2, the predecessor of the
ODROID-U3, based on the Samsung Exynos4412 Prime SoC.

v2 is reworked: as with other closely related boards, such as the
ODROID-X2 and the ODROID-X, the ODROID-U2 device tree now includes the
ODROID-U3 one and describes only the differences: the micro-USB port
is peripheral only, as there is no VBUS supply switch, there is no
expansion header with SPI, and the 3.5 mm jack is headphone only, with
an on-board digital microphone instead.

Ethernet, microSD, USB peripheral mode, the LED, the fan cooling
device, headphone playback and recording from the digital microphone
were tested on an ODROID-U2 with v1 on Linux 6.12. With v2, everything
except audio was checked again on Linux 6.18; the DTB is the same as in
v1, except for the cs-gpios property of the disabled spi_1 node. The
eMMC was not tested, as no eMMC module was available.

Changes in v2:
- Include the ODROID-U3 device tree instead of duplicating it, which
  also resolves the style issues reported by Henrik
- Add Reviewed-by from Henrik to the dt-bindings patch
- Link to v1: https://lore.kernel.org/all/20261018124459.3026-1-pepe.schlehofer@gmail.com/

Josef Schlehofer (2):
  dt-bindings: arm: samsung: Add Hardkernel ODROID-U2
  ARM: dts: samsung: Add Hardkernel ODROID-U2

 .../bindings/arm/samsung/samsung-boards.yaml  |  1 +
 arch/arm/boot/dts/samsung/Makefile            |  1 +
 .../dts/samsung/exynos4412-odroid-common.dtsi |  6 +--
 .../boot/dts/samsung/exynos4412-odroidu2.dts  | 42 +++++++++++++++++++
 4 files changed, 47 insertions(+), 3 deletions(-)
 create mode 100644 arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts


base-commit: 58161ead29e50d70a317ea26b472e0c7508e69da
-- 
2.54.0 (Apple Git-157)

[PATCH v2 1/2] dt-bindings: arm: samsung: Add Hardkernel ODROID-U2

[Josef Schlehofer]

Add Hardkernel ODROID-U2 board compatible string.

The ODROID-U2 is an Exynos 4412 Prime (Cortex-A9) based single board
computer featuring 2 GB LPDDR2 RAM, SMSC LAN9730 HSIC Ethernet, and
MAX98090 audio codec.

Reviewed-by: Henrik Grimler <henrik@grimler.se>
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
---
 .../devicetree/bindings/arm/samsung/samsung-boards.yaml          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml b/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
index 273464400477..f863803c84f8 100644
--- a/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
+++ b/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
@@ -86,6 +86,7 @@ properties:
         items:
           - enum:
               - friendlyarm,tiny4412            # FriendlyARM TINY4412
+              - hardkernel,odroid-u2            # Hardkernel Odroid U2
               - hardkernel,odroid-u3            # Hardkernel Odroid U3
               - hardkernel,odroid-x             # Hardkernel Odroid X
               - hardkernel,odroid-x2            # Hardkernel Odroid X2
-- 
2.54.0 (Apple Git-157)

[PATCH v2 2/2] ARM: dts: samsung: Add Hardkernel ODROID-U2

[Josef Schlehofer]

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.

Add a device tree for the board that includes the ODROID-U3 one and
describes only these differences, as the ODROID-X2 does with the
ODROID-X, and update the comments in the common dtsi, as the LDO22 and
BUCK8 constraints are now also used 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@gmail.com>
---
 arch/arm/boot/dts/samsung/Makefile            |  1 +
 .../dts/samsung/exynos4412-odroid-common.dtsi |  6 +--
 .../boot/dts/samsung/exynos4412-odroidu2.dts  | 42 +++++++++++++++++++
 3 files changed, 46 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..bc14df9be9f7
--- /dev/null
+++ b/arch/arm/boot/dts/samsung/exynos4412-odroidu2.dts
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardkernel's Exynos4412 based ODROID-U2 board device tree source
+ *
+ * Copyright (c) 2026 Josef Schlehofer <pepe.schlehofer@gmail.com>
+ *
+ * Device tree source file for Hardkernel's ODROID-U2 board which is based
+ * on Samsung's Exynos4412 SoC. The board is the predecessor of the
+ * ODROID-U3, so only the differences from it are described here.
+ */
+
+#include "exynos4412-odroidu3.dts"
+
+/ {
+	model = "Hardkernel ODROID-U2 board based on Exynos4412";
+	compatible = "hardkernel,odroid-u2", "samsung,exynos4412", "samsung,exynos4";
+};
+
+/* No VBUS supply switch on the micro-USB port */
+/delete-node/ &vbus_otg_reg;
+
+&hsotg {
+	dr_mode = "peripheral";
+	/delete-property/ vbus-supply;
+};
+
+&sound {
+	model = "Odroid-U2";
+	audio-routing = "Headphone Jack", "HPL",
+			"Headphone Jack", "HPR",
+			"DMICL", "DMIC",
+			"DMICR", "DMIC",
+			"Mixer DAI RX", "HiFi Capture";
+	samsung,audio-widgets =
+		"Headphone", "Headphone Jack",
+		"Microphone", "DMIC";
+};
+
+/* No expansion header with SPI */
+&spi_1 {
+	status = "disabled";
+};
-- 
2.54.0 (Apple Git-157)