linux-kernel - Re: [PATCH v2 1/2] dt-bindings: leds: Add LTC3220 18 channel LED Driver

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Message-ID: <20260113-wine-kingfisher-of-glee-cdac0c@quoll>
Date: Tue, 13 Jan 2026 09:06:59 +0100
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Edelweise Escala <edelweise.escala@...log.com>
Cc: Lee Jones <lee@...nel.org>, Pavel Machek <pavel@...nel.org>, 
	Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
	Conor Dooley <conor+dt@...nel.org>, linux-leds@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: leds: Add LTC3220 18 channel LED
 Driver

On Mon, Jan 12, 2026 at 04:55:54PM +0800, Edelweise Escala wrote:
> Document device tree bindings for the LTC3220 18-channel LED driver
> with I2C interface, individual brightness control, and hardware-assisted
> blink/gradation features.
> 
> Signed-off-by: Edelweise Escala <edelweise.escala@...log.com>
> ---

No changelog in the cover letter, no changelog here.

>  .../devicetree/bindings/leds/leds-ltc3220.yaml     | 120 +++++++++++++++++++++
>  MAINTAINERS                                        |   7 ++
>  2 files changed, 127 insertions(+)
> 

> +  adi,quick-write:
> +    type: boolean
> +    description:
> +      Enables the hardware quick-write feature where a write to the LED 1
> +      output register simultaneously updates all 18 LED output registers
> +      to the same value. Only applicable when LED 1 output is physically
> +      present and defined in the device tree.

I have doubts that this works fine. If you define 18 different LED
nodes, each can be controlled by user-space or kernel independently, but
with this property updates to LED 1 would overwrite updates to other
LEDs.

Isn't this then an aggregated LED, so in such case only one LED can be
defined in DT (optionally with 18 led-sources)?

> +
> +patternProperties:
> +  '^led@([1-9]|1[0-8])$':
> +    type: object
> +    $ref: /schemas/leds/common.yaml#
> +    unevaluatedProperties: false
> +    properties:
> +      reg:
> +        description: Output channel for the LED (1-18 maps to LED outputs D1-D18).
> +        minimum: 1
> +        maximum: 18

Best regards,
Krzysztof