[PATCH v3 3/3] ARM: dts: qcom: msm8960: expressatt: Add camera flash

Rudraksha Gupta via B4 Relay
2026-03-26T07:57:33Z

Add camera flash support for the Samsung Galaxy Express (expressatt).

The flash IC uses a one-wire pulse-count protocol on GPIO 3, powered
by a GPIO-controlled fixed regulator on PMIC MPP 4. The regulator is
modeled as a regulator-fixed node and supplied to the flash IC via
vin-supply.

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

Assisted-by: Claude:claude-opus-4.6
Reviewed-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
---
.../dts/qcom/qcom-msm8960-samsung-expressatt.dts | 43 ++++++++++++++++++++++
1 file changed, 43 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..35514fd53e3d 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 +62,32 @@ touchkey_enable: touchkey-enable {
regulator-boot-on;
};

+ vreg_flash: regulator-flash {
+ compatible = "regulator-fixed";
+ regulator-name = "VREG_FLASH_3P3";
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ gpio = <&pm8921_mpps 4 GPIO_ACTIVE_HIGH>;
+ enable-active-high;
+ pinctrl-0 = <&flash_led_unlock>;
+ pinctrl-names = "default";
+ };
+
+ led-controller {
+ compatible = "richtek,rt8515";
+ enf-gpios = <&tlmm 3 GPIO_ACTIVE_HIGH>;
+ vin-supply = <&vreg_flash>;
+ richtek,rfs-ohms = <16000>;
+ pinctrl-0 = <&cam_flash_en>;
+ pinctrl-names = "default";
+
+ led {
+ function = LED_FUNCTION_FLASH;
+ color = <LED_COLOR_ID_WHITE>;
+ flash-max-timeout-us = <250000>;
+ };
+ };
+
i2c-gpio-touchkey {
compatible = "i2c-gpio";
#address-cells = <1>;
@@ -172,6 +199,13 @@ touchscreen@4a {
};

&tlmm {
+ cam_flash_en: cam-flash-en-state {
+ pins = "gpio3";
+ function = "gpio";
+ drive-strength = <16>;
+ bias-pull-down;
+ };
+
spi1_default: spi1-default-state {
mosi-pins {
pins = "gpio6";
@@ -572,3 +606,12 @@ 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