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 D752CF5580B for ; Mon, 20 Apr 2026 11:00:37 +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=mjWQjP4IRSB5Wy14EhVD3hIP7KLN2LrKYzsuKbIxCnc=; b=m245xaRj0JGcYU/hv2tAUEkbUQ TB1OnmH5jzqqe7ttJJmCh0qddu6LhnWXofySCdMXj1paG7DqVZWp2m5KVNURJW6raxeaL5vwfbm7e T48+V+jNU0JGz7CeNRNBalG+9KGfH6T6J8QgDXC2gaKPWppHCoGZs3Ucz8RiI8Q5cCnBIzMZ7d1IJ J8qbrfEOCsOV0NLMxprN5NCpYxl3JW7hu08SDyyIResNilVXpUnG6e3TMlPBHyhIAfXAGMplmjphV nfv/j0ihWeoQnNwB5IKTcOFely9IYdafV56iHYKzrZSBikl7/N4lUy84gzpCYHpypCCwLuKg+UBES veUxJ9kA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wEmMj-00000006lBg-1iUV; Mon, 20 Apr 2026 11:00:33 +0000 Received: from bali.collaboradmins.com ([2a01:4f8:201:9162::2]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wEmMg-00000006lB6-2o1o; Mon, 20 Apr 2026 11:00:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1776682826; bh=PLPNmgPAxeK5mYLQnnUXuoPE4aCHhmjsyDeuAgufwss=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=K0CY6tvZ839+ED5+JnvY8glBhKFO790KScWfvsNhZDE9pe4jF7PrB2Kic+moM9ZW3 BIMal4m2vnG6ohpyr2fQrSFew483858a5b26SmlEuJbPp8jlIBh/QdXrFNXi3g0oDj kaJVEkPIdbGwNncdTi+RkrpomJ7ry+gwM7tTMx9SXcwFkTkzzH+boQ1JaWTRz0C2W2 dnmU7FH1m8muVP55ogcfnrHSzuaqVwNda+qefEMeGqYVIovbCSnv0q5ZFz8qr152qg RXiseB/qzTH0cnFahf7JzeZ5WxXvPCJuXEiQs0d2OiOa7s1ayeC3o0y90v0ZCWapkC 4V3yepyJhcRCg== 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 1CAE617E1388; Mon, 20 Apr 2026 13:00:26 +0200 (CEST) Message-ID: <401a020f-ca5d-4c7d-941e-f0288e144357@collabora.com> Date: Mon, 20 Apr 2026 14:00:25 +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> <2000470.6tgchFWduM@phil> <62f51359-9d91-4107-917b-cd722c7321c2@collabora.com> <2282688.C4sosBPzcN@phil> Content-Language: en-US From: Cristian Ciocaltea In-Reply-To: <2282688.C4sosBPzcN@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_040030_858746_E34BCE81 X-CRM114-Status: GOOD ( 26.33 ) 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 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. 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? > >>>> status = "okay"; >>>> }; >>>> >>>> @@ -655,7 +654,7 @@ &pcie0 { >>>> >>>> &pinctrl { >>>> hdmi { >>>> - hdmi_con_en: hdmi-con-en { >>>> + hdmi_frl_en: hdmi-frl-en { >>> >>> pinctrl names should ideally match the naming in schematics, for example the >>> "HDMI0_TX_ON_H" for jaguar and tiger. This makes it way easier to> go from DT >>> to schematics and back. >> >> I opted for a more descriptive name that could be used consistently across all >> boards, given that not all schematics are publicly available. >> >> You make a fair point though, we should probably stick with the pretty terrible >> hdmi[N]_tx_on_h naming instead. > > yep, we're doing that everywhere else already too, and sticking to the > schematics naming, also prevents any discussions about how something > should be named ;-) . Indeed. :)