From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 991C7D3B98E for ; Tue, 9 Dec 2025 19:07:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E9AE010E1D6; Tue, 9 Dec 2025 19:07:26 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="lwA+gXGm"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0D60710E1D6 for ; Tue, 9 Dec 2025 19:07:26 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id A8303431C5; Tue, 9 Dec 2025 19:07:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51CFDC4CEF5; Tue, 9 Dec 2025 19:07:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765307245; bh=Oym70OZBadIC1w/YlIPC9DL2FkmLeSFqIX49SQ+L7/g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lwA+gXGmpmgU5IwRHGVMFdXkRrn2+bkW/1NNddhQa7ZCTcOkRZKqNLyZxseM4ffEc tvoHjUes1u+9UfHDpaHfHBrJKjrOTB5C5P0qTNTSINvTke+8WiffQDDM7v6eRQ1QnF ALj2rikjP19zVrI4FCAiJ5V0WwVzuy6D22psHQrApox27xZXK5Y58q75kL3bEgSmkE YJOXdKxIk8hj3CNeYCUveh0d+yaWA/49Fe+x7I9Eumh+mweANs1I0FWElnnU8nX2FF jwpB+a4Ed6Ruh3KB7nMLnDd2wD3F6WE+vCqHXZmG9Q7zgTpxyzcTo6Q2vVCjya9ixP fEwMfQ3mJUIXw== Date: Tue, 9 Dec 2025 13:07:22 -0600 From: Rob Herring To: Maud Spierings Cc: Frank Li , Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Krzysztof Kozlowski , Conor Dooley , Helge Deller , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Liam Girdwood , Mark Brown , dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 1/4] dt-bindings: backlight: Add max25014 support Message-ID: <20251209190722.GA945742-robh@kernel.org> References: <20251201-max25014-v6-0-88e3ac8112ff@gocontroll.com> <20251201-max25014-v6-1-88e3ac8112ff@gocontroll.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Dec 08, 2025 at 02:56:50PM +0100, Maud Spierings wrote: > On 12/2/25 15:53, Frank Li wrote: > > On Tue, Dec 02, 2025 at 08:46:21AM +0100, Maud Spierings wrote: > > > On 12/1/25 17:52, Frank Li wrote: > > > > On Mon, Dec 01, 2025 at 12:53:20PM +0100, Maud Spierings via B4 Relay wrote: > > > > > From: Maud Spierings > > > > > > > > > > The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC > > > > > with integrated boost controller. > > > > > > > > > > Signed-off-by: Maud Spierings > > > > > > > > > > --- > > > > > > > > > > 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 > > > > > + > > > > > +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: > > > > > > > > define whole binding, allow 0-3. binding is not related with driver's > > > > implement. > > > > > > > > it'd better put unders leds. > > > > > > > > > > so like: > > > > > > backlight: backlight@6f { > > > compatible = "maxim,max25014"; > > > reg = <0x6f>; > > > enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>; > > > pinctrl-names = "default"; > > > pinctrl-0 = <&pinctrl_backlight>; > > > maxim,iset = <7>; > > > > > > leds { > > > #address-cells = <1>; > > > #size-cells = <0>; > > > > > > led@0 { > > > reg = <0>; > > > led-sources = <0 1 2>; > > > default-brightness = <50>; > > > }; > > > > > > optional led@#.... > > > }; > > > }; > > > > > > right? > > > > yes. > > > > I am feeling a bit weird about these led sub nodes, because it is not > programmed as a led driver, it is programmed as a backlight. I am trying to > figure out how this would be used later when the led strings are > individually controllable. > > it isn't possible to link the seperate strings to different displays because > it is only one backlight device, so I don't seen any reason why it would > ever be used in another way than what it is now, were all strings are > programmed by one register. > > The only way I can make sense of it is if instead I program this device as a > led driver and then use the led_bl driver as the actual backlight. > > Thats a pretty big step in a different direction, but then the led subnodes > at least can be properly used I feel. If you don't have any use for anything other than driving a single backlight, then I'd just drop the led nodes completely. Rob