From: Rudraksha Gupta <guptarud@gmail.com>
Date: Fri, 06 Mar 2026 16:58:04 -0800
Subject: [PATCH 3/3] ARM: dts: qcom: msm8960: expressatt: Add camera flash
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To: Lee Jones <lee@kernel.org>, Pavel Machek <pavel@kernel.org>, 
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 Konrad Dybcio <konradybcio@kernel.org>
Cc: linux-leds@vger.kernel.org, devicetree@vger.kernel.org, 
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Add camera flash support for the Samsung Galaxy Express (expressatt).

The flash IC uses a one-wire pulse-count protocol on GPIO 3, gated by
PMIC MPP 4 which must be driven high to unlock the flash circuit.

Downstream references:
Link: https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/drivers/leds/Makefile#L51
Link: https://github.com/LineageOS/android_kernel_samsung_d2/blob/stable/cm-12.0-YNG4N/arch/arm/mach-msm/board-apexq-camera.c#L591

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
 .../dts/qcom/qcom-msm8960-samsung-expressatt.dts   | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
index c4b98af6955d..96460775a4ec 100644
--- a/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
+++ b/arch/arm/boot/dts/qcom/qcom-msm8960-samsung-expressatt.dts
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/leds/common.h>
 #include <dt-bindings/reset/qcom,gcc-msm8960.h>
 
 #include "qcom-msm8960.dtsi"
@@ -61,6 +62,20 @@ touchkey_enable: touchkey-enable {
 		regulator-boot-on;
 	};
 
+	camera_flash: led-controller {
+		compatible = "richtek,rt8515";
+		enf-gpios = <&tlmm 3 GPIO_ACTIVE_HIGH>;
+		unlock-gpios = <&pm8921_mpps 4 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&cam_flash_en>;
+
+		led {
+			function = LED_FUNCTION_FLASH;
+			color = <LED_COLOR_ID_WHITE>;
+			flash-max-timeout-us = <250000>;
+		};
+	};
+
 	i2c-gpio-touchkey {
 		compatible = "i2c-gpio";
 		#address-cells = <1>;
@@ -247,6 +262,13 @@ touchkey_irq_pin: touchkey-irq-state {
 		drive-strength = <2>;
 		bias-disable;
 	};
+
+	cam_flash_en: cam-flash-en-state {
+		pins = "gpio3";
+		function = "gpio";
+		drive-strength = <16>;
+		bias-pull-down;
+	};
 };
 
 &pm8921 {
@@ -572,3 +594,12 @@ magnetometer@2e {
 		/* TODO: Figure out Mount Matrix */
 	};
 };
+
+&pm8921_mpps {
+	flash_led_unlock: flash-led-unlock-state {
+		pins = "mpp4";
+		function = "digital";
+		output-low;
+		power-source = <PM8921_GPIO_S4>;
+	};
+};

-- 
2.53.0