Subject: [PATCH v2 13/15] arm64: dts: st: support Engicam MicroGEA-STM32MP257-RMM board

From: Dario Binacchi <[email-masked]>
Date: Fri, 29 May 2026 16:46:27 +0200

Support for Engicam MicroGEA-STM32MP257-RMM board with:

 - 8 GB eMMC Flash
 - 2 GB LPDDR4 DRAM
 - CAN
 - LEDs
 - LCD panel with touchscreen
 - Micro SD card connector
 - Audio codec
 - Buzzer

Signed-off-by: Dario Binacchi <[email-masked]>

---

Changes in v2:
- Drop the clocks property from the sai1 node in stm32mp257-engicam-microgea-rmm.dts
  to avoid overriding the peripheral bus clock reference defined in the base
  SoC device tree. Suggested by Sashiko.
- Reference the existing labeled nodes directly at the root level using
  &sai1a and &sai1b in stm32mp257-engicam-microgea-rmm.dts instead of
  redefining the entire node structure and redeclaring the labels. Suggested by Sashiko.
- Drop the #clock-cells property from sai1a and remove the reference to sai1a from
  the clocks array in sai1b, relying strictly on the st,sync property to handle
  internal synchronization.

 arch/arm64/boot/dts/st/Makefile               |   1 +
 .../st/stm32mp257-engicam-microgea-rmm.dts    | 319 ++++++++++++++++++
 2 files changed, 320 insertions(+)
 create mode 100644 arch/arm64/boot/dts/st/stm32mp257-engicam-microgea-rmm.dts

diff --git a/arch/arm64/boot/dts/st/Makefile b/arch/arm64/boot/dts/st/Makefile
index 63908113ae36..386eca593c54 100644
--- a/arch/arm64/boot/dts/st/Makefile
+++ b/arch/arm64/boot/dts/st/Makefile
@@ -2,5 +2,6 @@
 dtb-$(CONFIG_ARCH_STM32) += \
 	stm32mp215f-dk.dtb \
 	stm32mp235f-dk.dtb \
+	stm32mp257-engicam-microgea-rmm.dtb \
 	stm32mp257f-dk.dtb \
 	stm32mp257f-ev1.dtb
diff --git a/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea-rmm.dts b/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea-rmm.dts
new file mode 100644
index 000000000000..0212c03aae1a
--- /dev/null
+++ b/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea-rmm.dts
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Amarula Solutions, Dario Binacchi <[email-masked]>
+ * Copyright (C) 2026 Engicam srl
+ */
+
+/dts-v1/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/leds/common.h>
+
+#include "stm32mp257-engicam-microgea.dtsi"
+
+/ {
+	model = "Engicam MicroGEA STM32MP257D RMM Board";
+	compatible = "engicam,microgea-stm32mp257-rmm",
+		     "engicam,microgea-stm32mp257", "st,stm32mp257";
+
+	aliases {
+		mmc0 = &sdmmc1;
+		mmc1 = &sdmmc2;
+		serial0 = &usart2;
+		serial1 = &usart1;
+	};
+
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		brightness-levels = <0 100>;
+		num-interpolated-steps = <100>;
+		default-brightness-level = <85>;
+		pwms = <&pwm2 0 100000 0>;
+	};
+
+	buzzer {
+		compatible = "pwm-beeper";
+		pwms = <&pwm4 0 1000000 0>;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		framebuffer {
+			compatible = "simple-framebuffer";
+			clocks = <&rcc CK_BUS_LTDC>, <&rcc CK_KER_LTDC>;
+			lcd-supply = <&reg_3v3>;
+			status = "disabled";
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led-0 {
+			gpios = <&gpioh 2 GPIO_ACTIVE_HIGH>;
+			default-state = "off";
+			status = "okay";
+		};
+
+		led-1 {
+			gpios = <&gpioh 6 GPIO_ACTIVE_HIGH>;
+			default-state = "off";
+			status = "okay";
+		};
+	};
+
+	mclk: clock-mclk {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <24000000>;
+	};
+
+	reg_1v8: regulator-1v8 {
+		compatible = "regulator-fixed";
+		regulator-name = "1v8";
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
+	reg_3v3: regulator-3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "3v3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
+	reg_ext_pwr: regulator-ext-pwr {
+		compatible = "regulator-fixed";
+		regulator-name = "ext-pwr";
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		gpio = <&gpiog 0 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+		regulator-always-on;
+	};
+
+	sound {
+		compatible = "audio-graph-card";
+		label = "STM32MP25-RMM";
+		widgets = "Headphone", "Headphone Jack",
+			  "Microphone", "Microphone Jack";
+		routing = "Headphone Jack", "HP_OUT",
+			  "MIC_IN", "Microphone Jack",
+			  "Microphone Jack", "Mic Bias";
+		dais = <&sai1a_port &sai1b_port>;
+		status = "okay";
+	};
+};
+
+&arm_wdt {
+	timeout-sec = <32>;
+	status = "okay";
+};
+
+&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 */
+	/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 = <1280>;
+		touchscreen-size-y = <800>;
+	};
+};
+
+&i2c2 {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&i2c2_pins_a>;
+	pinctrl-1 = <&i2c2_sleep_pins_a>;
+	i2c-scl-rising-time-ns = <185>;
+	i2c-scl-falling-time-ns = <20>;
+	status = "okay";
+	/* spare dmas for other usage */
+	/delete-property/dmas;
+	/delete-property/dma-names;
+
+	sgtl5000: codec@a {
+		compatible = "fsl,sgtl5000";
+		reg = <0x0a>;
+		#sound-dai-cells = <0>;
+		clocks = <&mclk>;
+
+		VDDA-supply = <&reg_3v3>;
+		VDDIO-supply = <&reg_3v3>;
+		VDDD-supply = <&reg_1v8>;
+
+		sgtl5000_port: port {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			sgtl5000_tx_endpoint: endpoint@0 {
+				reg = <0>;
+				remote-endpoint = <&sai1a_endpoint>;
+				frame-master = <&sgtl5000_tx_endpoint>;
+				bitclock-master = <&sgtl5000_tx_endpoint>;
+			};
+
+			sgtl5000_rx_endpoint: endpoint@1 {
+				reg = <1>;
+				remote-endpoint = <&sai1b_endpoint>;
+				frame-master = <&sgtl5000_rx_endpoint>;
+				bitclock-master = <&sgtl5000_rx_endpoint>;
+			};
+		};
+	};
+};
+
+&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>;
+	pinctrl-1 = <&m_can1_sleep_pins_a>;
+	status = "okay";
+};
+
+&sai1 {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&sai1a_pins_a>, <&sai1b_pins_a>;
+	pinctrl-1 = <&sai1a_sleep_pins_a>, <&sai1b_sleep_pins_a>;
+	status = "okay";
+};
+
+&sai1a {
+	dma-names = "tx";
+	status = "okay";
+
+	sai1a_port: port {
+		sai1a_endpoint: endpoint {
+			remote-endpoint = <&sgtl5000_tx_endpoint>;
+			dai-format = "i2s";
+			mclk-fs = <512>;
+		};
+	};
+};
+
+&sai1b {
+	dma-names = "rx";
+	st,sync = <&sai1a 2>;
+	clocks = <&rcc CK_KER_SAI1>;
+	clock-names = "sai_ck";
+	status = "okay";
+
+	sai1b_port: port {
+		sai1b_endpoint: endpoint {
+			remote-endpoint = <&sgtl5000_rx_endpoint>;
+			dai-format = "i2s";
+			mclk-fs = <512>;
+		};
+	};
+};
+
+/* MicroSD */
+&sdmmc1 {
+	pinctrl-names = "default", "opendrain", "sleep";
+	pinctrl-0 = <&sdmmc1_b4_pins_a>;
+	pinctrl-1 = <&sdmmc1_b4_od_pins_a>;
+	pinctrl-2 = <&sdmmc1_b4_sleep_pins_a>;
+	broken-cd;
+	disable-wp;
+	st,neg-edge;
+	bus-width = <4>;
+	vmmc-supply = <&scmi_v3v3>;
+	vqmmc-supply = <&scmi_vddio1>;
+	no-1-8-v;
+	status = "okay";
+};
+
+&spi1 {
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&spi1_pins_a>;
+	pinctrl-1 = <&spi1_sleep_pins_a>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	cs-gpios = <&gpioh 8 GPIO_ACTIVE_HIGH>, <&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 {
+	status = "okay";
+
+	pwm2: pwm {
+		pinctrl-0 = <&pwm2_pins_a>;
+		pinctrl-1 = <&pwm2_sleep_pins_a>;
+		pinctrl-names = "default", "sleep";
+		status = "okay";
+	};
+};
+
+&timers4 {
+	status = "okay";
+
+	pwm4: pwm {
+		pinctrl-names = "default", "sleep";
+		pinctrl-0 = <&pwm4_pins_a>;
+		pinctrl-1 = <&pwm4_sleep_pins_a>;
+		status = "okay";
+	};
+};
+
+&usart1 {
+	pinctrl-names = "default", "idle", "sleep";
+	pinctrl-0 = <&usart1_pins_b>;
+	pinctrl-1 = <&usart1_idle_pins_b>;
+	pinctrl-2 = <&usart1_sleep_pins_b>;
+	/delete-property/ dmas;
+	/delete-property/ dma-names;
+	status = "okay";
+};
+
+&usart2 {
+	pinctrl-names = "default", "idle", "sleep";
+	pinctrl-0 = <&usart2_pins_a>;
+	pinctrl-1 = <&usart2_idle_pins_a>;
+	pinctrl-2 = <&usart2_sleep_pins_a>;
+	/delete-property/ dmas;
+	/delete-property/ dma-names;
+	status = "okay";
+};
-- 
2.43.0