[PATCH 0/2] arm64: dts: st: add display overlays for Engicam MicroGEA-STM32MP257D-RMM

[PATCH 0/2] arm64: dts: st: add display overlays for Engicam MicroGEA-STM32MP257D-RMM

[Dario Binacchi]

The board is produced in variants fitted with different displays. Move
the current RGB panel to a device tree overlay and add one for the LVDS
variant, so that the board dts describes only what is common and each
display gets its own overlay.

Dario Binacchi (2):
  arm64: dts: st: move Engicam MicroGEA-STM32MP257D-RMM display to an
    overlay
  arm64: dts: st: add Engicam MicroGEA-STM32MP257D-RMM LVDS display
    overlay

 arch/arm64/boot/dts/st/Makefile               | 12 ++++
 ...gea-rmm-overlay-am-1280800w8tzqw-t00h.dtso | 67 ++++++++++++++++++
 ...icrogea-rmm-overlay-rk050hr345-ct106a.dtso | 69 +++++++++++++++++++
 .../st/stm32mp257d-engicam-microgea-rmm.dts   | 51 ++------------
 4 files changed, 152 insertions(+), 47 deletions(-)
 create mode 100644 arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtso
 create mode 100644 arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso

---
base-commit: 2f92d900f262a16c8ae02daf53ae2910d07185f5
branch: engicam-rmm-overlays

-- 
2.43.0

[PATCH 1/2] arm64: dts: st: move Engicam MicroGEA-STM32MP257D-RMM display to an overlay

[Dario Binacchi]

The board is fitted with different displays depending on the product
variant. Keep in the board dts only what is common to all variants and
move the RK050HR345-CT106A RGB panel and its touchscreen to an overlay.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 arch/arm64/boot/dts/st/Makefile               |  6 ++
 ...icrogea-rmm-overlay-rk050hr345-ct106a.dtso | 69 +++++++++++++++++++
 .../st/stm32mp257d-engicam-microgea-rmm.dts   | 49 +------------
 3 files changed, 78 insertions(+), 46 deletions(-)
 create mode 100644 arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso

diff --git a/arch/arm64/boot/dts/st/Makefile b/arch/arm64/boot/dts/st/Makefile
index 6cbccfd50993..218ff7fdf576 100644
--- a/arch/arm64/boot/dts/st/Makefile
+++ b/arch/arm64/boot/dts/st/Makefile
@@ -1,7 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0-only
+stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a-dtbs := \
+	stm32mp257d-engicam-microgea-rmm.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtbo
+
 dtb-$(CONFIG_ARCH_STM32) += \
 	stm32mp215f-dk.dtb \
 	stm32mp235f-dk.dtb \
 	stm32mp257d-engicam-microgea-rmm.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtbo \
 	stm32mp257f-dk.dtb \
 	stm32mp257f-ev1.dtb
diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso
new file mode 100644
index 000000000000..e64dd277ff09
--- /dev/null
+++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
+ * Copyright (C) 2026 Engicam srl
+ *
+ * Rocktech RK050HR345-CT106A 5" 480x854 RGB panel with EDT FT5306
+ * I2C touchscreen controller.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+
+&i2c1 {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&i2c1_pins_a>;
+	pinctrl-1 = <&i2c1_sleep_pins_a>;
+	i2c-scl-rising-time-ns = <185>;
+	i2c-scl-falling-time-ns = <20>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "okay";
+
+	touchscreen@38 {
+		compatible = "edt,edt-ft5306";
+		reg = <0x38>;
+		interrupt-parent = <&gpiob>;
+		interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
+		reset-gpios = <&gpiod 1 GPIO_ACTIVE_LOW>;
+		touchscreen-size-x = <480>;
+		touchscreen-size-y = <854>;
+	};
+};
+
+&ltdc {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&ltdc_pins_a>;
+	pinctrl-1 = <&ltdc_sleep_pins_a>;
+	status = "okay";
+
+	port {
+		ltdc_out: endpoint {
+			remote-endpoint = <&panel_in>;
+		};
+	};
+};
+
+&spi1 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	cs-gpios = <&gpioh 8 GPIO_ACTIVE_LOW>, <&gpioh 3 GPIO_ACTIVE_HIGH>;
+
+	display@0 {
+		compatible = "rocktech,rk050hr345-ct106a", "ilitek,ili9806e";
+		reg = <0>;
+		vdd-supply = <&reg_3v3>;
+		spi-max-frequency = <10000000>;
+		reset-gpios = <&gpiob 6 GPIO_ACTIVE_LOW>;
+		backlight = <&backlight>;
+
+		port {
+			panel_in: endpoint {
+				remote-endpoint = <&ltdc_out>;
+			};
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
index f5af0913bf1b..4b39b6c482d6 100644
--- a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
+++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
@@ -116,25 +116,9 @@ &arm_wdt {
 };
 
 &i2c1 {
-	pinctrl-names = "default", "sleep";
-	pinctrl-0 = <&i2c1_pins_a>;
-	pinctrl-1 = <&i2c1_sleep_pins_a>;
-	i2c-scl-rising-time-ns = <185>;
-	i2c-scl-falling-time-ns = <20>;
-	status = "okay";
-	/* spare dmas for other usage */
+	/* dt overlays don't support /delete-property/ */
 	/delete-property/dmas;
 	/delete-property/dma-names;
-
-	touchscreen@38 {
-		compatible = "edt,edt-ft5306";
-		reg = <0x38>;
-		interrupt-parent = <&gpiob>;
-		interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
-		reset-gpios = <&gpiod 1 GPIO_ACTIVE_LOW>;
-		touchscreen-size-x = <480>;
-		touchscreen-size-y = <854>;
-	};
 };
 
 &i2c2 {
@@ -179,19 +163,6 @@ sgtl5000_rx_endpoint: endpoint@1 {
 	};
 };
 
-&ltdc {
-	pinctrl-names = "default", "sleep";
-	pinctrl-0 = <&ltdc_pins_a>;
-	pinctrl-1 = <&ltdc_sleep_pins_a>;
-	status = "okay";
-
-	port {
-		ltdc_out: endpoint {
-			remote-endpoint = <&panel_in>;
-		};
-	};
-};
-
 &m_can1 {
 	pinctrl-names = "default", "sleep";
 	pinctrl-0 = <&m_can1_pins_a>;
@@ -257,23 +228,9 @@ &spi1 {
 	pinctrl-1 = <&spi1_sleep_pins_a>;
 	#address-cells = <1>;
 	#size-cells = <0>;
-	cs-gpios = <&gpioh 8 GPIO_ACTIVE_LOW>, <&gpioh 3 GPIO_ACTIVE_HIGH>;
+	/* CS0 is reserved for the display fitted through overlay */
+	cs-gpios = <0>, <&gpioh 3 GPIO_ACTIVE_HIGH>;
 	status = "okay";
-
-	display: display@0 {
-		compatible = "rocktech,rk050hr345-ct106a", "ilitek,ili9806e";
-		reg = <0>;
-		vdd-supply = <&reg_3v3>;
-		spi-max-frequency = <10000000>;
-		reset-gpios = <&gpiob 6 GPIO_ACTIVE_LOW>;
-		backlight = <&backlight>;
-
-		port {
-			panel_in: endpoint {
-				remote-endpoint = <&ltdc_out>;
-			};
-		};
-	};
 };
 
 &timers2 {
-- 
2.43.0

[PATCH 2/2] arm64: dts: st: add Engicam MicroGEA-STM32MP257D-RMM LVDS display overlay

[Dario Binacchi]

Add an overlay for the variant fitted with the AM-1280800W8TZQW-T00H
10.1" 1280x800 LVDS panel. Its touchscreen is connected over USB, so
there is no touchscreen node.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 arch/arm64/boot/dts/st/Makefile               |  6 ++
 ...gea-rmm-overlay-am-1280800w8tzqw-t00h.dtso | 67 +++++++++++++++++++
 .../st/stm32mp257d-engicam-microgea-rmm.dts   |  2 +-
 3 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtso

diff --git a/arch/arm64/boot/dts/st/Makefile b/arch/arm64/boot/dts/st/Makefile
index 218ff7fdf576..7f657d2bd629 100644
--- a/arch/arm64/boot/dts/st/Makefile
+++ b/arch/arm64/boot/dts/st/Makefile
@@ -1,4 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0-only
+stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h-dtbs := \
+	stm32mp257d-engicam-microgea-rmm.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtbo
+
 stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a-dtbs := \
 	stm32mp257d-engicam-microgea-rmm.dtb \
 	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtbo
@@ -7,6 +11,8 @@ dtb-$(CONFIG_ARCH_STM32) += \
 	stm32mp215f-dk.dtb \
 	stm32mp235f-dk.dtb \
 	stm32mp257d-engicam-microgea-rmm.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtb \
+	stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtbo \
 	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtb \
 	stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtbo \
 	stm32mp257f-dk.dtb \
diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtso b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtso
new file mode 100644
index 000000000000..7655c1bf56b1
--- /dev/null
+++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-am-1280800w8tzqw-t00h.dtso
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>
+ * Copyright (C) 2026 Engicam srl
+ *
+ * Ampire AM-1280800W8TZQW-T00H 10.1" 1280x800 LVDS panel. Its touchscreen
+ * controller is connected over USB.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/clock/st,stm32mp25-rcc.h>
+
+&{/} {
+	panel-lvds {
+		compatible = "ampire,am-1280800w8tzqw-t00h";
+		backlight = <&backlight>;
+		power-supply = <&reg_3v3>;
+
+		port {
+			panel_in: endpoint {
+				remote-endpoint = <&lvds_out>;
+			};
+		};
+	};
+};
+
+&framebuffer {
+	clocks = <&rcc CK_BUS_LTDC>, <&rcc CK_KER_LTDC>,
+		 <&rcc CK_BUS_LVDS>, <&rcc CK_KER_LVDSPHY>;
+};
+
+&ltdc {
+	status = "okay";
+
+	port {
+		ltdc_out: endpoint {
+			remote-endpoint = <&lvds_in>;
+		};
+	};
+};
+
+&lvds {
+	status = "okay";
+
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+
+			lvds_in: endpoint {
+				remote-endpoint = <&ltdc_out>;
+			};
+		};
+
+		port@1 {
+			reg = <1>;
+
+			lvds_out: endpoint {
+				remote-endpoint = <&panel_in>;
+			};
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
index 4b39b6c482d6..87d4bac1c89b 100644
--- a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
+++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
@@ -43,7 +43,7 @@ chosen {
 		#size-cells = <2>;
 		ranges;
 
-		framebuffer {
+		framebuffer: framebuffer {
 			compatible = "simple-framebuffer";
 			clocks = <&rcc CK_BUS_LTDC>, <&rcc CK_KER_LTDC>;
 			lcd-supply = <&reg_3v3>;
-- 
2.43.0

Re: [PATCH 1/2] arm64: dts: st: move Engicam MicroGEA-STM32MP257D-RMM display to an overlay

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dts: brittle overlay redefining unrelated SPI CS pins
--

commit c7c6310b15d9d720d97a1d231991f453b51ab1cf
Author: Dario Binacchi <dario.binacchi@amarulasolutions.com>

arm64: dts: st: move Engicam MicroGEA-STM32MP257D-RMM display to an overlay

This commit moves the RK050HR345-CT106A RGB panel and its touchscreen
configuration from the base device tree to a separate overlay. It leaves
common board elements intact to support multiple display variants.

> diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso
> --- /dev/null
> +++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm-overlay-rk050hr345-ct106a.dtso
[ ... ]
> +&spi1 {
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +	cs-gpios = <&gpioh 8 GPIO_ACTIVE_LOW>, <&gpioh 3 GPIO_ACTIVE_HIGH>;

[Severity: Low]
Since this overlay redefines the entire cs-gpios array, including the
unrelated CS1 pin (<&gpioh 3 GPIO_ACTIVE_HIGH>), could this silently revert
and break the CS1 device if the base board's CS1 wiring changes in the
future?

> +
> +	display@0 {
[ ... ]
> diff --git a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
> --- a/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
> +++ b/arch/arm64/boot/dts/st/stm32mp257d-engicam-microgea-rmm.dts
[ ... ]
> @@ -257,23 +228,9 @@ &spi1 {
>  	pinctrl-1 = <&spi1_sleep_pins_a>;
>  	#address-cells = <1>;
>  	#size-cells = <0>;
> -	cs-gpios = <&gpioh 8 GPIO_ACTIVE_LOW>, <&gpioh 3 GPIO_ACTIVE_HIGH>;
> +	/* CS0 is reserved for the display fitted through overlay */
> +	cs-gpios = <0>, <&gpioh 3 GPIO_ACTIVE_HIGH>;

[Severity: Low]
Does setting the base board's CS0 pin to a <0> placeholder force the overlay
to redefine the entire cs-gpios array? Would it be safer to let the base
board define the full physical cs-gpios array here (including CS0), allowing
the overlay to only append the SPI device node?

>  	status = "okay";

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260923152435.563925-1-dario.binacchi@amarulasolutions.com?part=1