From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f49.google.com (mail-wm1-f49.google.com [209.85.128.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF926399A60 for ; Wed, 14 Jan 2026 15:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768406021; cv=none; b=CA4QA9gJ6t34tXwxt14Ua8o7r9VeNmKTeXIOp5rAvVOlAKJwEnuUPV7yqL8EbS2uvft51v1Oh0Nm/uFdYrRnfQNrjxVr1JZvyDWHLbG6eo9FC/65Ls4ellbgYNDXjEDj13y7/tHOuIcvTaJwHG9kh8mANXE24WowchMiUDqWn30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768406021; c=relaxed/simple; bh=MjjY0CZe9m074IFDhBfEpVxdyYS7Z3Q8v4zhohpRutw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tKNEwnqJsQL3g7xolzdKvHfmUl9S1MnzTRQuL89rieiVtfB5cFIh6jAOHlHLfqZ+zUj4cw5d6bBOILblL6QheEj9mk350Tharwbr0R4oqo2nd4d+71pe+1P9kgSzzuwTdiik5YnR4jLcESMwBGlfq6R3QjRaPROCY//nKSOli5I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=riscstar.com; spf=pass smtp.mailfrom=riscstar.com; dkim=pass (2048-bit key) header.d=riscstar-com.20230601.gappssmtp.com header.i=@riscstar-com.20230601.gappssmtp.com header.b=hQOHDn7T; arc=none smtp.client-ip=209.85.128.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=riscstar.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=riscstar.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=riscstar-com.20230601.gappssmtp.com header.i=@riscstar-com.20230601.gappssmtp.com header.b="hQOHDn7T" Received: by mail-wm1-f49.google.com with SMTP id 5b1f17b1804b1-47d6a1f08bbso35947645e9.2 for ; Wed, 14 Jan 2026 07:53:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=riscstar-com.20230601.gappssmtp.com; s=20230601; t=1768406017; x=1769010817; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=mrePS2BeC/5/zU5iIVNiA/HxBMqtaGmBB9n2hBMQrA0=; b=hQOHDn7T8PjZDNbgPW6/0eJb4z6nY8heDKKRssw5W6YsE5B3CgY+QUeaMtbG5HIozl BDLBuXvzh89+smKariIFQ7c90ZLHqF628Z1MqBVZ3Q0VPI2tRK1eLhvGW0OojO9/Yey5 0xvtKFtmC/LqrRbPA6uFHC6hOnai1pCmRQ4cQxni+Ukjf1sv+M+V74u7x1+rJRu+ZEqm Cn67cB2aPBtozrafM2L2mXNDWC6YaMd77RDv+KdgxTi9bA3cbnjMlnHqeJ9cYxgEv2tR BTXWeUnO6BTE0YiKHa0DpdhBbZ0sDkFAKWi+INFckGy9OStXhLXTnm93tG7D8WZHQdU3 ne+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768406017; x=1769010817; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mrePS2BeC/5/zU5iIVNiA/HxBMqtaGmBB9n2hBMQrA0=; b=qtNNmeiexq+7E5SUVYRKihVViD5T++BHkh1EjpCTgTRYhimq+pSuhzzH16HneDHxu8 4RCGUgkjQXarUn9Yc/RljmldhZa1XxasMsxLWh/ULwRgkNKcj/YTBC55h5ze/g7afUZ0 p7vVBxFJfQm58MR62L3dx0hE9Hwif35PMagB7+KH5gpjHmg+mOLNa+QJr5Rpy0Dcu50r dW1Med0VdrYA5m+2/882taX4Kw0I8IhHHCtBolWuCE0EeLufNwlf4IvcKmNfgUUJ4xsQ OeOHRnwezcmodgZUMu6P9aR/ZiiPk0iV3snzH0j/IqGV/KdaIIS9PHu9raWSKC60ojMM ZbIw== X-Forwarded-Encrypted: i=1; AJvYcCUOFshJK54CV2Yc+wTkAsOELhMVfxBmAP+6eBOl/ru6r7J5Mrm2y8pMSydLbgV2wh0mxsXfha7EEE4XnOw=@vger.kernel.org X-Gm-Message-State: AOJu0Yx+pcPVHrGQDtrIRNDnaIhrWAGcYIVvMUfZZoLAZ3SXb29hF3bP xEx53cEPChmk5C7FQtcAejmMiEs1T+8cQWnxDvkOkjXQVD5t/TWUaLtiSUsz+9Wl00M= X-Gm-Gg: AY/fxX6u2anCuvO5SxjpVRodrBT2C/q/sHY491/acQvdyysP74c4T1bz1TmUmr9CWuw IAlb5zACFm2FhSM+0lji6RO657f5EnNehq35/BS/zf4ujqiYntGv6Q0oyTyqHirmfgPQwxhIXj5 JeOyMThCEMOAA0r6lYnrLXaSFcavJibRcK/jZadWj0fqM0etvPLfYCamX5xf40hO3aMuHAIJaTs xUtNw2HQQn1unjjotlB375vs0M31ECf8t4soN1kroSczoyQF6KDbJdsdCg8pTxmpbDTbLx98QP3 GPvX7xoZVeRhdE8eBiuM6w0Vw+AuWCa4xLOg0w9o3l5WnPmCHYky+FDoCrykuvgum0/CBpXhAa8 7O5YjdvKmSvrL1ii9I3RyvVxHhE0AhmhM2gZWGWrWu+XvvCgi3OiksmpLGEarwBtA47tMkh9mIf cYlBTWQt3qiKiHMp3091cJeyH/g1jJtAdVDKiPPkrLwx/vyif77G7l34xJyG1O3NsX0lt73WZ7h xG+GG+aza3QL8r4LLKi0+9fSXma/LndORR1kAai7Fn2b0qRYvfhB70bTIfFFZk4yQY2sHqr816c yQ9KJ8k= X-Received: by 2002:a05:600c:4515:b0:45c:4470:271c with SMTP id 5b1f17b1804b1-47ee339455dmr35015355e9.18.1768406016823; Wed, 14 Jan 2026 07:53:36 -0800 (PST) Received: from aspen.lan (aztw-34-b2-v4wan-166919-cust780.vm26.cable.virginm.net. [82.37.195.13]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-432bd5ee870sm51184009f8f.36.2026.01.14.07.53.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jan 2026 07:53:36 -0800 (PST) Date: Wed, 14 Jan 2026 15:53:34 +0000 From: Daniel Thompson To: tessolveupstream@gmail.com Cc: lee@kernel.org, danielt@kernel.org, jingoohan1@gmail.com, 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 Subject: Re: [PATCH v1 1/2] dt-bindings: backlight: gpio-backlight: allow multiple GPIOs Message-ID: References: <20260105085120.230862-1-tessolveupstream@gmail.com> <20260105085120.230862-2-tessolveupstream@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jan 13, 2026 at 10:15:53AM +0530, tessolveupstream@gmail.com wrote: > > > On 05-01-2026 15:25, Daniel Thompson wrote: > > On Mon, Jan 05, 2026 at 02:21:19PM +0530, Sudarshan Shetty wrote: > >> Update the gpio-backlight binding to support configurations that require > >> more than one GPIO for enabling/disabling the backlight. > >> > >> Signed-off-by: Sudarshan Shetty > >> --- > >> .../bindings/leds/backlight/gpio-backlight.yaml | 12 +++++++++++- > >> 1 file changed, 11 insertions(+), 1 deletion(-) > >> > >> diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> index 584030b6b0b9..1483ce4a3480 100644 > >> --- a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> +++ b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> @@ -17,7 +17,8 @@ properties: > >> > >> gpios: > >> description: The gpio that is used for enabling/disabling the backlight. > >> - maxItems: 1 > >> + minItems: 1 > >> + maxItems: 2 > > > > Why 2? > > > > In the current design, the LVDS panel has a single backlight that > is controlled by two GPIOs. Initially, It described as two separate > backlight devices using the same gpio-backlight driver, since the > existing driver supports only one GPIO per instance. > > So the maintainer suggested to extend the gpio-backlight driver > and bindings to support multiple GPIOs. > https://lore.kernel.org/all/q63bdon55app4gb2il5e7skyc6z2amcnaiqbqlhen7arkxphtb@3jejbelji2ti/ Right. So, once we support multiple GPIOs then why limit it to 2? Daniel.