Re: [PATCH v5 1/4] dt-bindings: backlight: Add max25014 supporty

Frank Li
2025-11-07T15:35:16Z

On Fri, Nov 07, 2025 at 01:49:58PM +0100, Maud Spierings via B4 Relay wrote:
> From: Maud Spierings <maudspierings@gocontroll.com>
>
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with integrated boost controller.
>
> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
>
> ---
>
> In the current implementation the control registers for channel 1,
> control all channels. So only one led subnode with led-sources is
> supported right now. If at some point the driver functionality is
> expanded the bindings can be easily extended with it.
> ---
> .../bindings/leds/backlight/maxim,max25014.yaml | 107 +++++++++++++++++++++
> MAINTAINERS | 5 +
> 2 files changed, 112 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> new file mode 100644
> index 000000000000..e83723224b07
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> @@ -0,0 +1,107 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim max25014 backlight controller
> +
> +maintainers:
> + - Maud Spierings <maudspierings@gocontroll.com>
> +
> +properties:
> + compatible:
> + enum:
> + - maxim,max25014
> +
> + reg:
> + maxItems: 1
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + enable-gpios:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + power-supply:
> + description: Regulator which controls the boost converter input rail.
> +
> + pwms:
> + maxItems: 1
> +
> + maxim,iset:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maximum: 15
> + default: 11
> + description:
> + Value of the ISET field in the ISET register. This controls the current
> + scale of the outputs, a higher number means more current.
> +
> + led@0:
> + type: object
> + description: Properties for a string of connected LEDs.
> + $ref: common.yaml#
> +
> + properties:
> + reg:
> + const: 0

If reg is const 0, why need use led@0?

Frank

> +
> + led-sources:
> + allOf:
> + - minItems: 1
> + maxItems: 4
> + items:
> + minimum: 0
> + maximum: 3
> + default: [0, 1, 2, 3]
> +
> + default-brightness:
> + minimum: 0
> + maximum: 100
> + default: 50
> +
> + required:
> + - reg
> +
> + additionalProperties: false
> +
> +required:
> + - compatible
> + - reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + backlight@6f {
> + compatible = "maxim,max25014";
> + reg = <0x6f>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
> + power-supply = <&reg_backlight>;
> + pwms = <&pwm1>;
> + maxim,iset = <7>;
> +
> + led@0 {
> + reg = <0>;
> + led-sources = <0 1 2 3>;
> + default-brightness = <50>;
> + };
> + };
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 58c7e3f678d8..606ce086f758 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15261,6 +15261,11 @@ F: Documentation/userspace-api/media/drivers/max2175.rst
> F: drivers/media/i2c/max2175*
> F: include/uapi/linux/max2175.h
>
> +MAX25014 BACKLIGHT DRIVER
> +M: Maud Spierings <maudspierings@gocontroll.com>
> +S: Maintained
> +F: Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> +
> MAX31335 RTC DRIVER
> M: Antoniu Miclaus <antoniu.miclaus@analog.com>
> L: linux-rtc@vger.kernel.org
>
> --
> 2.51.2
>
>