[PATCH 1/3] dt-bindings: leds: rt8515: Support single-GPIO flash ICs with unlock gate

Rudraksha Gupta via B4 Relay
2026-03-07T00:58:03Z

From: Rudraksha Gupta <guptarud@gmail.com>

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 <guptarud@gmail.com>
---
.../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 <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/leds/common.h>
+
+ 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 = <LED_COLOR_ID_WHITE>;
+ flash-max-timeout-us = <250000>;
+ };
+ };
+
...

--
2.53.0