From: Rudraksha Gupta Date: Fri, 06 Mar 2026 16:58:02 -0800 Subject: [PATCH 1/3] dt-bindings: leds: rt8515: Support single-GPIO flash ICs with unlock gate MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260306-expressatt_camera_flash-v1-1-b1996f7cdfdd@gmail.com> References: <20260306-expressatt_camera_flash-v1-0-b1996f7cdfdd@gmail.com> In-Reply-To: <20260306-expressatt_camera_flash-v1-0-b1996f7cdfdd@gmail.com> To: Lee Jones , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Linus Walleij , Bjorn Andersson , Konrad Dybcio Cc: linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Rudraksha Gupta X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1772845083; l=2686; i=guptarud@gmail.com; s=20240916; h=from:subject:message-id; bh=XkKexDy/wzuB27iB2DnLFEzKOovyf++JmlP+fQT4Q6o=; b=he6Q2vN99zHB/nJKmrP5qVDhXsKuAugWXRoYsVze3J2hDLS/1EGDegxeETpbLfSdCc+i4D8XY PVNa65EVPyMCnkBk9e5dqxgRft8bIKI1MvtPOQ5pHGJcJtxpHI7rYic X-Developer-Key: i=guptarud@gmail.com; a=ed25519; pk=ETrudRugWAtOpr0OhRiheQ1lXM4Kk4KGFnBySlKDi2I= X-Endpoint-Received: by B4 Relay for guptarud@gmail.com/20240916 with auth_id=211 List-Id: B4 Relay Submissions Some flash ICs use the same one-wire pulse-count protocol as the RT8515 but have only a single GPIO line for both flash and torch modes, plus an optional unlock gate (e.g. a PMIC MPP) that must be driven high before the chip responds to the enable GPIO. Make ent-gpios optional and add an unlock-gpios property to support these variants. Add a oneOf constraint requiring exactly one of ent-gpios or unlock-gpios. Add a binding example showing the single-GPIO configuration. Signed-off-by: Rudraksha Gupta --- .../devicetree/bindings/leds/richtek,rt8515.yaml | 36 +++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/leds/richtek,rt8515.yaml b/Documentation/devicetree/bindings/leds/richtek,rt8515.yaml index 0356371a6b01..820cf8c55090 100644 --- a/Documentation/devicetree/bindings/leds/richtek,rt8515.yaml +++ b/Documentation/devicetree/bindings/leds/richtek,rt8515.yaml @@ -15,6 +15,10 @@ description: | current for each mode is defined in hardware using two resistors RFS and RTS. + This driver also supports single-GPIO flash ICs that use the same + one-wire pulse-count protocol on one line for both flash and torch. + For these, only enf-gpios is required. + properties: compatible: const: richtek,rt8515 @@ -26,6 +30,14 @@ properties: ent-gpios: maxItems: 1 description: A connection to the 'ENT' (enable torch) pin. + Optional for single-GPIO flash ICs where enf-gpios is used for + both flash and torch modes. + + unlock-gpios: + maxItems: 1 + description: Optional GPIO to unlock the flash LED circuit. Some + boards use a PMIC MPP pin that must be driven high before the + flash IC will respond to the enable GPIOs. richtek,rfs-ohms: minimum: 7680 @@ -81,10 +93,15 @@ properties: required: - compatible - - ent-gpios - enf-gpios - led +oneOf: + - required: + - ent-gpios + - required: + - unlock-gpios + additionalProperties: false examples: @@ -108,4 +125,21 @@ examples: }; }; + - | + /* Single-GPIO flash IC with unlock gate */ + #include + #include + + led-controller { + compatible = "richtek,rt8515"; + enf-gpios = <&tlmm 3 GPIO_ACTIVE_HIGH>; + unlock-gpios = <&pm8921_mpps 4 GPIO_ACTIVE_HIGH>; + + led { + function = LED_FUNCTION_FLASH; + color = ; + flash-max-timeout-us = <250000>; + }; + }; + ... -- 2.53.0