From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 873D7280CF6; Wed, 28 Jan 2026 10:11:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769595098; cv=none; b=MEWewb6woIgU5SW0KnNFwJvoFytkyWHFsv9w70QjVaSDYnWBtfWca5FBMvhvz8L3YP62kH2rCUY3mS846VpOpHFtbRgEAxjqu+nKX6xQP8fB99rDLsNAxvNxJTy7cVl7EBTUOuB62JLvkdjfg/7O2BPP96vS7RqsGe/xYLfkJFo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769595098; c=relaxed/simple; bh=/7iKJZCZoHs1YwMeYq4ekxV0CY5gX14lgEXa5PnEbSQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FPb6mO92MCOd09zgK+qtFF5gEsQbsQe2TR0HhPt6E9AFQVqLE89gJZkFm0U0SFlKmU5Wrom+CzYITYmDhU1TnksEXhSD0w5+jYEprhDVAmCUtahKVI4zETBA4qGcoI60l5cvBYxCkHwu6hwK5hFNRRdAmNClcKBlrQenQ9/zG3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TSKHQeAa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TSKHQeAa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4207CC4CEF1; Wed, 28 Jan 2026 10:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769595098; bh=/7iKJZCZoHs1YwMeYq4ekxV0CY5gX14lgEXa5PnEbSQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TSKHQeAaPJ4t++802gREcxoHTtkLt7JGs2ZmwkV8eB9AYKu+pGdXI7R2YdIrL5hG3 EmUDzi24HRiSvD8cB2Dqr/UR7Me4XRMe6Aa4xwIsi+RqR4xBXQwqekE30ueC92RD9z pikO3URPRqbgDeB2JelJ2x6xw4Q8v+kkcfTWqaP+wsbTG1JzZ7kGgPuKGrNmvrLQWh T/GdZ98Kdp/IvtSsA7+YQKmRSl+9xfnO6GClGyc6Z4FGwVP9DI6KLDMgpCulBaYxxo zIi+naVeGytozHrjfaSMbcjnx6WW7X2hMjbB6hmCMnHoDpDQqCuQBRjGcAGpmRLEK/ hPnDvT4oD9KIg== Message-ID: <500b603d-5abc-4c45-8d56-bbc88fc85b83@kernel.org> Date: Wed, 28 Jan 2026 11:11:33 +0100 Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/2] dt-bindings: backlight: gpio-backlight: allow multiple GPIOs To: tessolveupstream@gmail.com, lee@kernel.org, danielt@kernel.org, jingoohan1@gmail.com Cc: deller@gmx.de, pavel@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260120125036.2203995-1-tessolveupstream@gmail.com> <20260120125036.2203995-2-tessolveupstream@gmail.com> <3f3c47ea-1660-4bd4-ab89-3bdf58217995@kernel.org> <54d156ba-e177-4059-a808-2505983b4e2e@gmail.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 23/01/2026 12:11, tessolveupstream@gmail.com wrote: > > > On 20-01-2026 20:01, Krzysztof Kozlowski wrote: >> On 20/01/2026 13:50, Sudarshan Shetty wrote: >>> Update the gpio-backlight binding to support configurations that require >>> more than one GPIO for enabling/disabling the backlight. >> >> >> Why? Which devices need it? How a backlight would have three enable >> GPIOs? I really do not believe, so you need to write proper hardware >> justification. >> > > To clarify our hardware setup: > the panel requires one GPIO for the backlight enable signal, and it > also has a PWM input. Since the QCS615 does not provide a PWM controller > for this use case, the PWM input is connected to a GPIO that is driven > high to provide a constant 100% duty cycle, as explained in the link > below. > https://lore.kernel.org/all/20251028061636.724667-1-tessolveupstream@gmail.com/T/#m93ca4e5c7bf055715ed13316d91f0cd544244cf5 That's not an enable gpio, but PWM. You write bindings for this device, not for something else - like your board. > >>> >>> Signed-off-by: Sudarshan Shetty >>> --- >>> .../leds/backlight/gpio-backlight.yaml | 24 +++++++++++++++++-- >>> 1 file changed, 22 insertions(+), 2 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml >>> index 584030b6b0b9..4e4a856cbcd7 100644 >>> --- a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml >>> +++ b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml >>> @@ -16,8 +16,18 @@ properties: >>> const: gpio-backlight >>> >>> gpios: >>> - description: The gpio that is used for enabling/disabling the backlight. >>> - maxItems: 1 >>> + description: | >>> + The gpio that is used for enabling/disabling the backlight. >>> + Multiple GPIOs can be specified for panels that require several >>> + enable signals. All GPIOs are controlled together. >>> + type: array >> >> There is no such syntax in the bindings, from where did you get it? Type >> is already defined. >> >> items: >> minItems: 1 >> maxItems: 3 >> >> >>> + minItems: 1 >>> + items: >>> + type: array >>> + minItems: 3 >>> + maxItems: 3 >>> + items: >>> + type: integer >> >> All this is some odd stuff - just to be clear, don't send us LLM output. >> I don't want to waste my time to review microslop. >> >> Was it done with help of Microslop? >> > > I understand now that the schema changes I proposed were not correct, How such code could be even created... Just in case, do you understand that Microslop and LLM is waste of our time? > and I will address this in the next patch series. My intention was to > check whether the gpio-backlight binding could support more than one > enable-type GPIO. > Could you please advise what would be an appropriate maximum number of > GPIOs for gpio-backlight in such a scenario? For example, would allowing > 2 GPIOs be acceptable, or should this case be handled in a different way? We have plenty of examples for this, but anyway you won't need it because this is not an enable GPIO. Best regards, Krzysztof