[PATCH v2 0/3] Add support for Seeed Studio BeagleBone HDMI cape overlay

[PATCH v2 0/3] Add support for Seeed Studio BeagleBone HDMI cape overlay

[Kory Maincent (TI)]

Add devicetree overlay for the Seeed Studio BeagleBone HDMI cape, which
provides HDMI output via an ITE IT66121 HDMI bridge and audio support
through McASP.

https://www.seeedstudio.com/Seeed-Studio-BeagleBoner-Green-HDMI-Cape.html

This overlay requires the recent tilcdc cleanup patch series that was merged
to drm-misc-next to function properly:
https://lore.kernel.org/lkml/20260123-feature_tilcdc-v5-0-5a44d2aa3f6f@bootlin.com/

With this DRM tree dependency I don't know if this series should land in
DRM tree or in OMAP tree.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
Changes in v2:
- Enable overlays only for am335x BeagleBoard boards.
- Squash defconfig changes in one patch.
- Link to v1: https://lore.kernel.org/r/20260212-feature_bbge-v1-0-29014a212f35@bootlin.com

---
Kory Maincent (TI) (3):
      ARM: dts: ti: Enable overlays for am335x BeagleBoard devicetrees
      ARM: multi_v7_defconfig: omap2plus_defconfig: Enable ITE IT66121 driver
      ARM: dts: am335x: Add Seeed Studio BeagleBone HDMI cape overlay

 arch/arm/boot/dts/ti/omap/Makefile                 |  13 ++
 .../boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso    | 157 +++++++++++++++++++++
 arch/arm/configs/multi_v7_defconfig                |   2 +
 arch/arm/configs/omap2plus_defconfig               |   1 +
 4 files changed, 173 insertions(+)
---
base-commit: 40c1ccc1a3b86259e455a9a5082d5c8e0f944d62
change-id: 20260212-feature_bbge-932870b2edf5

Best regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

[PATCH v2 1/3] ARM: dts: ti: Enable overlays for am335x BeagleBoard devicetrees

[Kory Maincent (TI)]

Allow overlays to be applied to am335x BeagleBoard boards. This adds
around ~40% to the total size of the DTB files on average.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---

Changes in v2:
- Enable overlays only for am335x BeagleBoard boards.
---
 arch/arm/boot/dts/ti/omap/Makefile | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/ti/omap/Makefile b/arch/arm/boot/dts/ti/omap/Makefile
index 14e500846875e..dcc6d4422e411 100644
--- a/arch/arm/boot/dts/ti/omap/Makefile
+++ b/arch/arm/boot/dts/ti/omap/Makefile
@@ -175,3 +175,11 @@ dtb-$(CONFIG_SOC_TI81XX) += \
 	dm8148-t410.dtb \
 	dm8168-evm.dtb \
 	dra62x-j5eco-evm.dtb
+
+# Enable support for device-tree overlays
+DTC_FLAGS_am335x-bone += -@
+DTC_FLAGS_am335x-boneblack += -@
+DTC_FLAGS_am335x-boneblack-wireless += -@
+DTC_FLAGS_am335x-bonegreen += -@
+DTC_FLAGS_am335x-bonegreen-wireless += -@
+DTC_FLAGS_am335x-bonegreen-eco += -@

-- 
2.43.0

[PATCH v2 2/3] ARM: multi_v7_defconfig: omap2plus_defconfig: Enable ITE IT66121 driver

[Kory Maincent (TI)]

Enable the ITE IT66121 HDMI bridge driver to support HDMI output on
the BeagleBone Green with the Seeed Studio HDMI cape.

Enable CONFIG_DRM_TILCDC as a module on multi_v7_defconfig to provide
display support for TI AM335x-based SoCs in this kernel configuration.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---

Changes in v2:
- Squash defconfig changes in one patch.
---
 arch/arm/configs/multi_v7_defconfig  | 2 ++
 arch/arm/configs/omap2plus_defconfig | 1 +
 2 files changed, 3 insertions(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 7f1fa9dd88c92..2c9587855f044 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -735,6 +735,7 @@ CONFIG_DRM_RCAR_DU=m
 CONFIG_DRM_SUN4I=m
 CONFIG_DRM_OMAP=m
 CONFIG_OMAP5_DSS_HDMI=y
+CONFIG_DRM_TILCDC=m
 CONFIG_DRM_MSM=m
 CONFIG_DRM_FSL_DCU=m
 CONFIG_DRM_TEGRA=y
@@ -750,6 +751,7 @@ CONFIG_DRM_PANEL_SAMSUNG_S6E63J0X03=m
 CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0=m
 CONFIG_DRM_PANEL_SHARP_LQ101R1SX01=m
 CONFIG_DRM_DISPLAY_CONNECTOR=m
+CONFIG_DRM_ITE_IT66121=m
 CONFIG_DRM_LVDS_CODEC=m
 CONFIG_DRM_NXP_PTN3460=m
 CONFIG_DRM_PARADE_PS8622=m
diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
index 4e53c331cd841..cdf69ac2e5126 100644
--- a/arch/arm/configs/omap2plus_defconfig
+++ b/arch/arm/configs/omap2plus_defconfig
@@ -486,6 +486,7 @@ CONFIG_VIDEO_OMAP3=m
 CONFIG_VIDEO_MT9P031=m
 CONFIG_VIDEO_TVP5150=m
 CONFIG_DRM=m
+CONFIG_DRM_ITE_IT66121=m
 CONFIG_DRM_OMAP=m
 CONFIG_OMAP5_DSS_HDMI=y
 CONFIG_OMAP2_DSS_SDI=y

-- 
2.43.0

[PATCH v2 3/3] ARM: dts: am335x: Add Seeed Studio BeagleBone HDMI cape overlay

[Kory Maincent (TI)]

Add devicetree overlay for the Seeed Studio BeagleBone HDMI cape, which
provides HDMI output via an ITE IT66121 HDMI bridge and audio support
through McASP.

The cape is designed for BeagleBone Green but is also compatible with
BeagleBone and BeagleBone Black due to pin compatibility.

Link: https://www.seeedstudio.com/Seeed-Studio-BeagleBoner-Green-HDMI-Cape.html
Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
 arch/arm/boot/dts/ti/omap/Makefile                 |   5 +
 .../boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso    | 157 +++++++++++++++++++++
 2 files changed, 162 insertions(+)

diff --git a/arch/arm/boot/dts/ti/omap/Makefile b/arch/arm/boot/dts/ti/omap/Makefile
index dcc6d4422e411..d70706e6d467b 100644
--- a/arch/arm/boot/dts/ti/omap/Makefile
+++ b/arch/arm/boot/dts/ti/omap/Makefile
@@ -82,6 +82,10 @@ dtb-$(CONFIG_ARCH_OMAP4) += \
 	omap4-var-stk-om44.dtb \
 	omap4-xyboard-mz609.dtb \
 	omap4-xyboard-mz617.dtb
+
+am335x-bonegreen-hdmi-00a0-dtbs := am335x-bonegreen-eco.dtb \
+	am335x-bone-hdmi-00a0.dtbo
+
 dtb-$(CONFIG_SOC_AM33XX) += \
 	am335x-baltos-ir2110.dtb \
 	am335x-baltos-ir3220.dtb \
@@ -94,6 +98,7 @@ dtb-$(CONFIG_SOC_AM33XX) += \
 	am335x-bonegreen.dtb \
 	am335x-bonegreen-wireless.dtb \
 	am335x-bonegreen-eco.dtb \
+	am335x-bonegreen-hdmi-00a0.dtb \
 	am335x-chiliboard.dtb \
 	am335x-cm-t335.dtb \
 	am335x-evm.dtb \
diff --git a/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso b/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso
new file mode 100644
index 0000000000000..f43f44c79c96d
--- /dev/null
+++ b/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 2017 Copyright (c) Seeed Technology Inc.  All right reserved.
+ * Author: Baozhu Zuo <zuobaozhu@gmail.com>
+ * Copyright (c) Bootlin 2026
+ *
+ * This device tree overlay is compatible with the BeagleBone Black, Green
+ * and their subversions.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/pinctrl/am33xx.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+
+&{/} {
+	hdmi0: connector-hdmi {
+		compatible = "hdmi-connector";
+		label = "hdmi";
+		type = "a";
+		port {
+			hdmi_connector_in: endpoint {
+				remote-endpoint = <&it66121_out>;
+			};
+		};
+	};
+
+	clk_mcasp0_fixed: clk-mcasp0-fixed {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <24576000>;
+	};
+
+	clk_mcasp0: clk-mcasp0 {
+		#clock-cells = <0>;
+		compatible = "gpio-gate-clock";
+		clocks = <&clk_mcasp0_fixed>;
+		enable-gpios = <&gpio1 27 0>;
+	};
+
+	sound {
+		compatible = "simple-audio-card";
+		simple-audio-card,name = "TI BeagleBone Green HDMI cape";
+		simple-audio-card,format = "i2s";
+		simple-audio-card,bitclock-master = <&sound_master>;
+		simple-audio-card,frame-master = <&sound_master>;
+
+		sound_master: simple-audio-card,cpu {
+			sound-dai = <&mcasp0>;
+			clocks = <&clk_mcasp0>;
+		};
+
+		simple-audio-card,codec {
+			sound-dai = <&it66121>;
+		};
+	};
+};
+
+&am33xx_pinmux {
+	bb_lcd_pins: pinmux-bb-lcd-pins {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA0, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA1, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA2, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA3, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA4, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA5, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA6, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA7, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA8, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA9, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA10, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA11, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA12, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA13, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA14, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA15, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_VSYNC, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_HSYNC, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_PCLK, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_AC_BIAS_EN, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_ADVN_ALE, PIN_OUTPUT_PULLDOWN, MUX_MODE7)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_OEN_REN, PIN_OUTPUT_PULLDOWN, MUX_MODE7)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_WEN, PIN_INPUT, MUX_MODE7)
+		>;
+	};
+	mcasp0_pins: mcasp0-pins {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_AHCLKX, PIN_INPUT_PULLUP, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_AHCLKR, PIN_OUTPUT_PULLDOWN, MUX_MODE2)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_FSX, PIN_OUTPUT_PULLUP, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_ACLKX, PIN_OUTPUT_PULLDOWN, MUX_MODE0)
+		>;
+	};
+};
+
+&i2c2 {
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	it66121: it66121 {
+		compatible = "ite,it66121";
+		reg = <0x4d>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bb_lcd_pins>;
+
+		#sound-dai-cells = <0>;
+
+		interrupt-parent = <&gpio2>;
+		interrupts = <4 IRQ_TYPE_EDGE_RISING>;
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				it66121_in: endpoint {
+					bus-width = <24>;
+					remote-endpoint = <&lcdc_0>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+				it66121_out: endpoint {
+					remote-endpoint = <&hdmi_connector_in>;
+				};
+			};
+		};
+	};
+};
+
+&lcdc {
+	status = "okay";
+	blue-and-red-wiring = "straight";
+	port {
+		lcdc_0: endpoint@0 {
+			remote-endpoint = <&it66121_in>;
+		};
+	};
+};
+
+
+&mcasp0 {
+	status = "okay";
+	#sound-dai-cells = <0>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&mcasp0_pins>;
+	op-mode = <0>;
+	tdm-slots = <2>;
+	serial-dir = < 0 0 1 0 >;
+	tx-num-evt = <32>;
+	rx-num-evt = <32>;
+};
+

-- 
2.43.0

Claude review: Add support for Seeed Studio BeagleBone HDMI cape overlay

[Claude Code Review Bot]

Overall Series Review

Subject: Add support for Seeed Studio BeagleBone HDMI cape overlay
Author: "Kory Maincent (TI)" <kory.maincent@bootlin.com>
Patches: 4
Reviewed: 2026-02-17T05:55:37.746198

---

This is a 3-patch series adding support for the Seeed Studio BeagleBone HDMI cape, which uses an ITE IT66121 HDMI bridge chip connected via I2C and parallel RGB from the AM335x LCDC, plus McASP for HDMI audio. The series is straightforward: patch 1 enables DTC overlay support (`-@` flag) for BeagleBone board DTBs, patch 2 enables the relevant kernel config options in two defconfigs, and patch 3 adds the actual devicetree overlay and wires up the composite DTB build.

The overall approach is reasonable. Using a `.dtso` overlay is the right pattern for a cape that may or may not be physically present. The composite DTB approach (merging the overlay with `am335x-bonegreen-eco.dtb`) is consistent with how other TI overlays work in this directory (e.g., `am57xx-evm`, `am571x-idk-overlays`).

I have a few minor observations but no significant bugs. The series is mostly clean.

---
Generated by Claude Code Patch Reviewer

Claude review: ARM: dts: ti: Enable overlays for am335x BeagleBoard devicetrees

[Claude Code Review Bot]

Patch Review

> +# Enable support for device-tree overlays
> +DTC_FLAGS_am335x-bone += -@
> +DTC_FLAGS_am335x-boneblack += -@
> +DTC_FLAGS_am335x-boneblack-wireless += -@
> +DTC_FLAGS_am335x-bonegreen += -@
> +DTC_FLAGS_am335x-bonegreen-wireless += -@
> +DTC_FLAGS_am335x-bonegreen-eco += -@

This enables the `-@` flag (emit `__symbols__` node) for the listed boards so overlays can reference their labels. The commit message notes it adds ~40% DTB size, which is a worthwhile trade-off for overlay support. The set of boards listed matches the boards the cover letter describes as compatible (Bone, Black, Green variants).

No issues found.

---
Generated by Claude Code Patch Reviewer

Claude review: ARM: multi_v7_defconfig: omap2plus_defconfig: Enable ITE IT66121 driver

[Claude Code Review Bot]

Patch Review

> +CONFIG_DRM_TILCDC=m

> +CONFIG_DRM_ITE_IT66121=m

The `multi_v7_defconfig` gets both `CONFIG_DRM_TILCDC=m` and `CONFIG_DRM_ITE_IT66121=m`, while `omap2plus_defconfig` only gets `CONFIG_DRM_ITE_IT66121=m`. This makes sense -- `omap2plus_defconfig` presumably already has `CONFIG_DRM_TILCDC` enabled (it's the OMAP-specific config), while the broader `multi_v7` config did not.

No issues found.

---
Generated by Claude Code Patch Reviewer

Claude review: ARM: dts: am335x: Add Seeed Studio BeagleBone HDMI cape overlay

[Claude Code Review Bot]

Patch Review

> +am335x-bonegreen-hdmi-00a0-dtbs := am335x-bonegreen-eco.dtb \
> +	am335x-bone-hdmi-00a0.dtbo

The composite DTB uses `am335x-bonegreen-eco.dtb` as the base. The cover letter says the cape is "compatible with BeagleBone and BeagleBone Black due to pin compatibility," but only one composite DTB is produced for the Green Eco variant. This seems intentional (the primary target board), but it might be worth noting that users of other boards would need to apply the overlay manually at runtime.

> +	it66121: it66121 {
> +		compatible = "ite,it66121";
> +		reg = <0x4d>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&bb_lcd_pins>;

The LCD pin muxing is assigned via `pinctrl-0` on the IT66121 I2C device node rather than on the `&lcdc` node. This is somewhat unusual -- typically you would expect the display controller to own its output pin configuration. However, since this is an overlay, placing it on the bridge device that "triggers" the need for these pins is a pragmatic approach, and the pinctrl framework will configure the pins when the IT66121 device probes. It works, though it could be argued the pins are more logically associated with the LCDC.

> +	sound {
> +		compatible = "simple-audio-card";
> +		simple-audio-card,name = "TI BeagleBone Green HDMI cape";

Minor nit: the product is "Seeed Studio BeagleBone Green HDMI cape" according to the commit message and Link, but the audio card name says "TI BeagleBone Green HDMI cape." This is cosmetic but could be confusing -- it mixes the board vendor (TI/BeagleBone) with the cape vendor (Seeed Studio).

> +&lcdc {
> +	status = "okay";
> +	blue-and-red-wiring = "straight";
> +	port {
> +		lcdc_0: endpoint@0 {
> +			remote-endpoint = <&it66121_in>;
> +		};
> +	};
> +};

The `lcdc` node in `am33xx-l4.dtsi` has `status = "disabled"` by default, so enabling it here is correct. The `blue-and-red-wiring = "straight"` property is a tilcdc-specific property indicating no R/B swap.

> +&mcasp0 {
> +	status = "okay";
> +	#sound-dai-cells = <0>;
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&mcasp0_pins>;
> +	op-mode = <0>;
> +	tdm-slots = <2>;
> +	serial-dir = < 0 0 1 0 >;
> +	tx-num-evt = <32>;
> +	rx-num-evt = <32>;
> +};

The McASP configuration looks standard for I2S stereo output (tdm-slots=2, one serializer transmitting at index 2). No issues here.

> +		enable-gpios = <&gpio1 27 0>;

The `0` for the GPIO flags means `GPIO_ACTIVE_HIGH`. This could be written as `GPIO_ACTIVE_HIGH` for readability by including `<dt-bindings/gpio/gpio.h>`, but using the raw value `0` is not incorrect.

Overall this is a clean overlay. No correctness bugs found.

---
Generated by Claude Code Patch Reviewer