[PATCH 0/6] Add LCD and LVDS controller for sama7d65 SoC

[PATCH 0/6] Add LCD and LVDS controller for sama7d65 SoC

[Manikandan Muralidharan]

This patch series adds support for image subsystem nodes
like LCD and LVDS controller in sama7d65 SoC with binidngs.
Also takes care of enabling the required configs.

Aubin Constans (1):
  ARM: configs: at91: sama7: enable LVDS serializer support

Manikandan Muralidharan (1):
  dt-bindings: display: bridge: microchip,sam9x75-lvds: document
    SAMA7D65 binding

Romain Sioen (1):
  ARM: configs: at91: sama7: enable config for atmel maxtouch

Ryan Wanner (3):
  ARM: dts: microchip: sama7d65: add LCD controller
  ARM: dts: microchip: sama7d65: add LVDS controller
  ARM: configs: at91: sama7: enable DRM hlcdc support

 .../bridge/microchip,sam9x75-lvds.yaml        |  6 +++-
 arch/arm/boot/dts/microchip/sama7d65.dtsi     | 35 +++++++++++++++++++
 arch/arm/configs/sama7_defconfig              | 10 ++++++
 3 files changed, 50 insertions(+), 1 deletion(-)


base-commit: 7dff99b354601dd01829e1511711846e04340a69
-- 
2.25.1

[PATCH 1/6] ARM: dts: microchip: sama7d65: add LCD controller

[Manikandan Muralidharan]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

Add support for LCD controller node

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 arch/arm/boot/dts/microchip/sama7d65.dtsi | 26 +++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/arm/boot/dts/microchip/sama7d65.dtsi b/arch/arm/boot/dts/microchip/sama7d65.dtsi
index e21556f46384..b2fe76115aec 100644
--- a/arch/arm/boot/dts/microchip/sama7d65.dtsi
+++ b/arch/arm/boot/dts/microchip/sama7d65.dtsi
@@ -278,6 +278,32 @@ sdmmc1: mmc@e1208000 {
 			status = "disabled";
 		};
 
+		xlcdc: lcd-controller@e1400000{
+			compatible = "microchip,sama7d65-xlcdc";
+			reg = <0xe1400000 0x2000>;
+			interrupts = <GIC_SPI 56 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&pmc PMC_TYPE_PERIPHERAL 56>, <&pmc PMC_TYPE_GCK 56>, <&clk32k 1>;
+			clock-names = "periph_clk", "sys_clk", "slow_clk";
+			status = "disabled";
+
+			display-controller {
+				compatible = "atmel,hlcdc-display-controller";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				port@0 {
+					reg = <0>;
+					#address-cells = <1>;
+					#size-cells = <0>;
+				};
+			};
+
+			pwm {
+				compatible = "atmel,hlcdc-pwm";
+				#pwm-cells = <3>;
+			};
+		};
+
 		aes: crypto@e1600000 {
 			compatible = "microchip,sama7d65-aes", "atmel,at91sam9g46-aes";
 			reg = <0xe1600000 0x100>;
-- 
2.25.1

Claude review: ARM: dts: microchip: sama7d65: add LCD controller

[Claude Code Review Bot]

Patch Review

**Critical issue — missing fallback compatible will break DRM probe:**

The DRM display controller driver at `drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c:766` does:
```c
match = of_match_node(atmel_hlcdc_of_match, dev->dev->parent->of_node);
```
The `atmel_hlcdc_of_match` table (line 569–598) contains `"microchip,sam9x75-xlcdc"` but **not** `"microchip,sama7d65-xlcdc"`. This means the DRM probe will fail with `"invalid compatible string"` and the display won't work.

The LVDS node in patch 3 correctly uses a fallback compatible (`"microchip,sama7d65-lvds", "microchip,sam9x75-lvds"`), but this LCD node does not. The fix is either:
- Add a fallback compatible: `compatible = "microchip,sama7d65-xlcdc", "microchip,sam9x75-xlcdc";` (and update the MFD binding to match this pattern), or
- Include a separate patch adding `sama7d65-xlcdc` to the DRM driver's match table with appropriate data

**Style issue — missing space before `{`:**
```
+		xlcdc: lcd-controller@e1400000{
```
Should be:
```
		xlcdc: lcd-controller@e1400000 {
```

The node content itself looks correct: reg, interrupts, clocks, clock-names, display-controller subnode, and pwm subnode all follow the existing pattern from `sam9x7.dtsi`.

---
Generated by Claude Code Patch Reviewer

[PATCH 2/6] dt-bindings: display: bridge: microchip, sam9x75-lvds: document SAMA7D65 binding

[Manikandan Muralidharan]

Update the microchip LVDS bridge device tree bindings to support the
SAMA7D65 SoC LVDS controller

Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 .../bindings/display/bridge/microchip,sam9x75-lvds.yaml     | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/microchip,sam9x75-lvds.yaml b/Documentation/devicetree/bindings/display/bridge/microchip,sam9x75-lvds.yaml
index 862ef441ac9f..669ef2393659 100644
--- a/Documentation/devicetree/bindings/display/bridge/microchip,sam9x75-lvds.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/microchip,sam9x75-lvds.yaml
@@ -17,7 +17,11 @@ description:
 
 properties:
   compatible:
-    const: microchip,sam9x75-lvds
+    oneOf:
+      - const: microchip,sam9x75-lvds
+      - items:
+          - const: microchip,sama7d65-lvds
+          - const: microchip,sam9x75-lvds
 
   reg:
     maxItems: 1
-- 
2.25.1

Re: [PATCH 2/6] dt-bindings: display: bridge: microchip,sam9x75-lvds: document SAMA7D65 binding

[Krzysztof Kozlowski]

On Wed, Feb 25, 2026 at 02:24:26PM +0530, Manikandan Muralidharan wrote:
> Update the microchip LVDS bridge device tree bindings to support the
> SAMA7D65 SoC LVDS controller
> 
> Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
> ---
>  .../bindings/display/bridge/microchip,sam9x75-lvds.yaml     | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>

A nit, subject: drop second/last, redundant "binding". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Claude review: dt-bindings: display: bridge: microchip, sam9x75-lvds: document SAMA7D65 binding

[Claude Code Review Bot]

Patch Review

This patch looks correct. It changes the LVDS binding from a single `const` to a `oneOf` with either the bare `sam9x75-lvds` or a `sama7d65-lvds` + `sam9x75-lvds` fallback pair:

```yaml
+    oneOf:
+      - const: microchip,sam9x75-lvds
+      - items:
+          - const: microchip,sama7d65-lvds
+          - const: microchip,sam9x75-lvds
```

This is the standard and correct DT binding pattern for a new SoC-specific compatible that falls back to an existing driver compatible. No issues here.

**Ordering note:** Convention is to place binding patches before DTS patches in a series. This should be patch 1, before the DTS additions.

---
Generated by Claude Code Patch Reviewer

[PATCH 3/6] ARM: dts: microchip: sama7d65: add LVDS controller

[Manikandan Muralidharan]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

Add support for LVDS controller node

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 arch/arm/boot/dts/microchip/sama7d65.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/boot/dts/microchip/sama7d65.dtsi b/arch/arm/boot/dts/microchip/sama7d65.dtsi
index b2fe76115aec..8aa38f29082b 100644
--- a/arch/arm/boot/dts/microchip/sama7d65.dtsi
+++ b/arch/arm/boot/dts/microchip/sama7d65.dtsi
@@ -304,6 +304,15 @@ pwm {
 			};
 		};
 
+		lvdsc: lvds-controller@e1408000 {
+			compatible = "microchip,sama7d65-lvds", "microchip,sam9x75-lvds";
+			reg = <0xe1408000 0x100>;
+			interrupts = <GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&pmc PMC_TYPE_PERIPHERAL 104>;
+			clock-names = "pclk";
+			status = "disabled";
+		};
+
 		aes: crypto@e1600000 {
 			compatible = "microchip,sama7d65-aes", "atmel,at91sam9g46-aes";
 			reg = <0xe1600000 0x100>;
-- 
2.25.1

Claude review: ARM: dts: microchip: sama7d65: add LVDS controller

[Claude Code Review Bot]

Patch Review

The LVDS controller node looks correct and properly uses the fallback compatible as documented in patch 2:

```
+		lvdsc: lvds-controller@e1408000 {
+			compatible = "microchip,sama7d65-lvds", "microchip,sam9x75-lvds";
```

The address `0xe1408000` is properly ordered in the DT between the LCD controller (`0xe1400000`) and the crypto block (`0xe1600000`). The properties (reg, interrupts, clocks, clock-names, status) match the binding schema requirements. This patch depends on patch 1 (it inserts after the xlcdc node added there) and patch 2 (it uses the newly-documented compatible). No issues.

---
Generated by Claude Code Patch Reviewer

[PATCH 4/6] ARM: configs: at91: sama7: enable DRM hlcdc support

[Manikandan Muralidharan]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

Add configs for DRM Atmel LCD Controller, Backlight and Simple Panel

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 arch/arm/configs/sama7_defconfig | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/configs/sama7_defconfig b/arch/arm/configs/sama7_defconfig
index e2ad9a05566f..c0671318bac4 100644
--- a/arch/arm/configs/sama7_defconfig
+++ b/arch/arm/configs/sama7_defconfig
@@ -133,6 +133,7 @@ CONFIG_GENERIC_ADC_THERMAL=y
 CONFIG_WATCHDOG=y
 CONFIG_SAMA5D4_WATCHDOG=y
 CONFIG_MFD_ATMEL_FLEXCOM=y
+CONFIG_MFD_ATMEL_HLCDC=y
 CONFIG_REGULATOR=y
 CONFIG_REGULATOR_FIXED_VOLTAGE=y
 CONFIG_REGULATOR_MCP16502=y
@@ -147,6 +148,11 @@ CONFIG_VIDEO_MICROCHIP_CSI2DC=y
 CONFIG_VIDEO_IMX219=m
 CONFIG_VIDEO_IMX274=m
 CONFIG_VIDEO_OV5647=m
+CONFIG_DRM=y
+CONFIG_DRM_ATMEL_HLCDC=y
+CONFIG_DRM_PANEL_SIMPLE=y
+CONFIG_BACKLIGHT_CLASS_DEVICE=y
+CONFIG_BACKLIGHT_PWM=y
 CONFIG_SOUND=y
 CONFIG_SND=y
 CONFIG_SND_SOC=y
@@ -197,6 +203,7 @@ CONFIG_AT91_SAMA5D2_ADC=y
 CONFIG_PAC1934=m
 CONFIG_PWM=y
 CONFIG_PWM_ATMEL=y
+CONFIG_PWM_ATMEL_HLCDC_PWM=y
 CONFIG_MCHP_EIC=y
 CONFIG_RESET_CONTROLLER=y
 CONFIG_NVMEM_MICROCHIP_OTPC=y
-- 
2.25.1

Claude review: ARM: configs: at91: sama7: enable DRM hlcdc support

[Claude Code Review Bot]

Patch Review

Enables the necessary config options for the LCD controller:

```
+CONFIG_MFD_ATMEL_HLCDC=y
+CONFIG_DRM=y
+CONFIG_DRM_ATMEL_HLCDC=y
+CONFIG_DRM_PANEL_SIMPLE=y
+CONFIG_BACKLIGHT_CLASS_DEVICE=y
+CONFIG_BACKLIGHT_PWM=y
+CONFIG_PWM_ATMEL_HLCDC_PWM=y
```

The set of options looks complete and correctly covers the full stack (MFD parent, DRM driver, panel, backlight, PWM). No issues with the config changes themselves.

---
Generated by Claude Code Patch Reviewer

[PATCH 5/6] ARM: configs: at91: sama7: enable config for atmel maxtouch

[Manikandan Muralidharan]

From: Romain Sioen <romain.sioen@microchip.com>

Add config support to enable maxtouch capacitive touchscreen

Signed-off-by: Romain Sioen <romain.sioen@microchip.com>
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 arch/arm/configs/sama7_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/sama7_defconfig b/arch/arm/configs/sama7_defconfig
index c0671318bac4..0f1a3abc4640 100644
--- a/arch/arm/configs/sama7_defconfig
+++ b/arch/arm/configs/sama7_defconfig
@@ -108,6 +108,8 @@ CONFIG_CAN_M_CAN_PLATFORM=y
 CONFIG_INPUT_EVDEV=y
 CONFIG_KEYBOARD_GPIO=y
 # CONFIG_INPUT_MOUSE is not set
+CONFIG_INPUT_TOUCHSCREEN=y
+CONFIG_TOUCHSCREEN_ATMEL_MXT=y
 CONFIG_LEGACY_PTY_COUNT=4
 CONFIG_SERIAL_ATMEL=y
 CONFIG_SERIAL_ATMEL_CONSOLE=y
-- 
2.25.1

Claude review: ARM: configs: at91: sama7: enable config for atmel maxtouch

[Claude Code Review Bot]

Patch Review

```
+CONFIG_INPUT_TOUCHSCREEN=y
+CONFIG_TOUCHSCREEN_ATMEL_MXT=y
```

**This patch doesn't belong in this series.** The cover letter describes this as adding "LCD and LVDS controller" support. A touchscreen driver config is a separate concern — even if the development board happens to have a touchscreen, it should be submitted as a separate patch or in a board-enablement series, not bundled with display controller support.

---
Generated by Claude Code Patch Reviewer

[PATCH 6/6] ARM: configs: at91: sama7: enable LVDS serializer support

[Manikandan Muralidharan]

From: Aubin Constans <aubin.constans@microchip.com>

Add config support to enable LVDS serializer

Signed-off-by: Aubin Constans <aubin.constans@microchip.com>
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 arch/arm/configs/sama7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/sama7_defconfig b/arch/arm/configs/sama7_defconfig
index 0f1a3abc4640..e52f671ccec4 100644
--- a/arch/arm/configs/sama7_defconfig
+++ b/arch/arm/configs/sama7_defconfig
@@ -152,6 +152,7 @@ CONFIG_VIDEO_IMX274=m
 CONFIG_VIDEO_OV5647=m
 CONFIG_DRM=y
 CONFIG_DRM_ATMEL_HLCDC=y
+CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER=y
 CONFIG_DRM_PANEL_SIMPLE=y
 CONFIG_BACKLIGHT_CLASS_DEVICE=y
 CONFIG_BACKLIGHT_PWM=y
-- 
2.25.1

Claude review: ARM: configs: at91: sama7: enable LVDS serializer support

[Claude Code Review Bot]

Patch Review

```
+CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER=y
```

Straightforward, enables the LVDS serializer bridge driver to match the LVDS controller node added in patch 3. No issues.

**Minor series-level note:** The cover letter has a typo: "binidngs" should be "bindings".

---
Generated by Claude Code Patch Reviewer

Claude review: Add LCD and LVDS controller for sama7d65 SoC

[Claude Code Review Bot]

Overall Series Review

Subject: Add LCD and LVDS controller for sama7d65 SoC
Author: Manikandan Muralidharan <manikandan.m@microchip.com>
Patches: 8
Reviewed: 2026-02-27T13:48:28.796406

---

This 6-patch series adds LCD (XLCDC) and LVDS controller device tree nodes for the Microchip SAMA7D65 SoC, updates the LVDS binding, and enables relevant defconfig options. The series is straightforward but has a **critical functional issue**: the LCD controller DT node uses `compatible = "microchip,sama7d65-xlcdc"` without a fallback compatible, and the DRM driver (`atmel_hlcdc_dc.c`) does **not** have this compatible in its `atmel_hlcdc_of_match` table. The DRM driver probe uses `of_match_node(atmel_hlcdc_of_match, dev->dev->parent->of_node)` to find the layer descriptors — this lookup will fail, and the display controller will not work at runtime. The MFD driver side is fine (it already has the match), but the DRM side is broken.

Additionally, the series mixes an unrelated touchscreen config change into a display-focused series, has a minor DT style issue, and uses a non-standard patch ordering.

---
Generated by Claude Code Patch Reviewer