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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2F2EEF588EA for ; Mon, 20 Apr 2026 15:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OZaJBIhgsDq0upYh4RqdlXEmj6l683FqTBoGfv+TMvM=; b=Iq1tVTVoCM2TZrYRY48UFMkciO WeSSrMs2Eh90kkbO8ePrU017wxx0UYiwH2RvgJazSePU9cn5vah97QmN0Oy38LPppl9HN3gfIjZsd 1ICyT66dZNZR05O1hDqt4VgZ21TULJPFlgZG3tbkNvWOv3MopN6umCZYZthbk8s4Hn7kBwIZffFEJ /BJfJaB4OaQpa7q6DH1Vi/n45CvTdvsRxmO0iKgwCVQlM9xfWZ1vDanpx2W4B+5lYKEt0QAtzP61v LFxek9WIIEGwPBq6lVf8PeeDC9VPG/rF5VJJGIWne9UBUzAdF9HJedpjny28YMOhlt4AFE6wPCuxu lZJ7wLMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wEqwJ-00000007Nih-20Tp; Mon, 20 Apr 2026 15:53:35 +0000 Received: from bali.collaboradmins.com ([148.251.105.195]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wEqwH-00000007Ni5-20Zu; Mon, 20 Apr 2026 15:53:34 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1776700406; bh=AD5SU7VAHmOec5494xhlBBXbP87I8anCA//9QBwyto4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=DqsBU3cAZqitqjmVK+sLr4bmFIpQ0J6XbYpByue8a6Mbcc3TfQS1UPd9g9fZ0wS4L 2pmXCQHwczCr5cK9WTdkdbmG3PakX0/qnZnEl1vutxb6PLUYbOn4kZnpicMQtrGe7K bQ4AbJ7yV0Td+uwv+qzpGNzR9V+MgL/ydHQ2imXC46kmQidtbLOMQAOq3ucEaoRK2l /6Qv9yJzeadicJbQJSZoDDgDMODBTjzPqgKtE2Iesm3SYErdK7AHEr+lj26iBHecV6 0o0mY/7DcEF3VN+kZwl2mYqxrfXss8KIP4iUdw7918pAagajKHrEYYgZeIVcykIJqR kHoRpmFhAvk+g== Received: from [100.64.0.241] (unknown [100.64.0.241]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id 9105517E137D; Mon, 20 Apr 2026 17:53:26 +0200 (CEST) Message-ID: <693537c8-b7d9-40e9-9c53-284c1af78e06@collabora.com> Date: Mon, 20 Apr 2026 18:53:26 +0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 05/40] arm64: dts: rockchip: Add frl-enable-gpios to rk3576-luckfox-core3576 To: Heiko Stuebner , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: kernel@collabora.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260417-dts-rk-frl-enable-gpios-v1-0-a19c0dd8c9f6@collabora.com> <2282688.C4sosBPzcN@phil> <401a020f-ca5d-4c7d-941e-f0288e144357@collabora.com> <2480203.yKrmzQ4Hd0@phil> Content-Language: en-US From: Cristian Ciocaltea In-Reply-To: <2480203.yKrmzQ4Hd0@phil> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260420_085333_760104_DD3EE308 X-CRM114-Status: GOOD ( 25.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 4/20/26 6:18 PM, Heiko Stuebner wrote: > Am Montag, 20. April 2026, 13:00:25 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea: >> Hi Heiko, >> >> On 4/18/26 2:12 AM, Heiko Stuebner wrote: >>> Hi Cristian, >>> >>> Am Freitag, 17. April 2026, 18:34:17 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea: >>>> On 4/17/26 2:32 PM, Heiko Stuebner wrote: >>>>> the comments below apply sort of to all patches in that series. >>>>> >>>>> Am Freitag, 17. April 2026, 11:24:39 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea: >>>>>> The board exposes the GPIO4_C6 line to control the voltage bias on the >>>>>> HDMI data lines. It must be asserted when operating in HDMI 2.1 FRL >>>>>> mode and deasserted for HDMI 1.4/2.0 TMDS mode. >>>>>> >>>>>> Wire up the HDMI node to the GPIO line using the frl-enable-gpios >>>>>> property and drop the line from the vcc_5v0_hdmi regulator to allow >>>>>> adjusting the bias when transitioning between TMDS and FRL operating >>>>>> modes. >> >> [...] >> >>>>> >>>>> >>>>>> @@ -231,6 +228,8 @@ &gpu { >>>>>> }; >>>>>> >>>>>> &hdmi { >>>>>> + pinctrl-0 = <&hdmi_txm0_pins &hdmi_tx_scl &hdmi_tx_sda &hdmi_frl_en>; >>>>>> + frl-enable-gpios = <&gpio4 RK_PC6 GPIO_ACTIVE_LOW>; >>>>> >>>>> this should be sorted the other way around I think. >>>>> >>>>> Also please provide a pinctrl-names property too. If for whatever reason >>>>> the dw-hdmi aquires a 2nd pinctrl state in the future, this makes sure >>>>> board DTs are staying in the "old" compatible mode until they are adapted. >>>> >>>> Just to make sure I fully understand, the convention is that >>>> >>>> pinctrl-names = "default"; >>>> >>>> should be always provided, even when the node overrides an existing pinctrl-0 >>>> property? >>>> >>>> E.g. in rk3576.dtsi we have: >>>> >>>> hdmi: hdmi@27da0000 { >>>> ... >>>> pinctrl-names = "default"; >>>> pinctrl-0 = <&hdmi_txm0_pins &hdmi_tx_scl &hdmi_tx_sda>; >>>> ... >>>> } >>>> >>>> Hence I omitted pinctrl-names which doesn't change and just appended >>>> &hdmi_frl_en to pinctrl-0's original value. >>> >>> correct, please always provide a pinctrl-names entry when setting a new >>> pinctrl-0 . >>> >>> The background is, imagine you have a base: >>> >>> pinctrl-names = "default"; >>> pinstrl-0 = <....>; >>> >>> and override pinctrl-0 in a board. >>> >>> Now a newer binding introduces a 2nd pinctrl state "foo". Of course >>> we're backwards compatible, and both are valid and the driver checks >>> what states are defined. >>> >>> So the base sets: >>> pinctrl-names = "default", "foo"; >>> pinctrl-0 = <...>; >>> pinctrl-1 = <...>; >>> >>> in your (old) board you override pinctrl-0, but the driver still sees >>> the new variant with 2 pinctrl states, where it should've stayed with >>> the legacy 1-state, until the board-dts might get adapted in the future. >>> >>> >>> And I know, we're likely not doing that everywhere, and also in most >>> cases it won't really matter, but still it is safer and sets the better >>> precedent :-) . >> >> Thanks for the detailed explanation, that clears things up! >> >> There are several other nodes (e.g. i2c, pwm, uart) that also lack >> pinctrl-names despite providing pinctrl-0 - I can address those in a >> separate patch. > > As said above it is an ideal to aspire to (having -names together with > defining states), but if you want to add the "missing" -names, > go ahead :-) . > > >> I also noticed an inconsistency in property ordering: some nodes place >> pinctrl-names before pinctrl- and others after. I have always used >> the former, but we should probably prefer the latter to stay consistent >> with how clocks, resets, phys, etc. are ordered. >> >> Thoughts? > > There is sort of a "conflict" between regular ordering and possibly > better readability. I.e. the dt-writing guidelines propose alphabetical > ordering which I guess puts numbers before letters. > > On the other hand the semantic definition of list the states and then > define them (names first, -0, -1, etc second) looks more sensible from > a understanding standpoint. > > > But there we'd end up with special rules, so just sticking to the > base sorting will cause less friction in the long run I think. > Aka, -0, -1 first; -names after, follows the main sorting suggestions > so it's easy to explain to newcomers. Yes, that seems like a good enough reason to go with this approach. > But please don't re-sort existing entries :-) Oh, no, it's just for the current changes. :-) Thanks, Cristian