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 1518B2E659; Thu, 5 Jun 2025 14:41:46 +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=1749134507; cv=none; b=CNsz10f0OqisqDKzii286y93lWK9YKVbzB/lJcq8C3TrLfCtXLx6iHYaZFNOvAcH122v733vfT5k5lRII699qv94d2BEP/TQp+Wv+y+9ThHos3fU4N5olQipm6bp+hnesihwL12VaJUyImya+4fAdj2JjH+hLFq+NZUFU/SX6jA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749134507; c=relaxed/simple; bh=yO5fqt9HuK0kjVxjDKW2m26zjnbn/JAZBHwnXsXNWqQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GQd02+Y5s/Ewc12ru8zg1Q2LfiauCFt8wIAbYsHwP0MftS5Jlv1fkWAyeCpGpZ9gabBc4bRPf4olnXIqvlpSM74ULoMmv52b0MXGFEwtUnE3ts18sFGXiY+NGuJU7Lrs4x2c9vz5WRFxGYwiLhL0scwjTd38RUCBuSC8clGkgFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WzNbi196; 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="WzNbi196" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4351AC4CEEB; Thu, 5 Jun 2025 14:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749134506; bh=yO5fqt9HuK0kjVxjDKW2m26zjnbn/JAZBHwnXsXNWqQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WzNbi196JZko7WsBkAtNHT7clAsU2rlKFe1W4Ry43owbvfA8kIZMgoGmnSVuNUUiR nQSF0LTyLqzNrTrYsEqDG9WyrzGG61wZbmz9OA7zpuKH+w5roTplYwUmuAJ3TXMn3e TjrRtqrKO03hyYGUMpmOeRbhP+RfHMaHWyW9NnZBJdkNVOe3rr/NP2zbYtZJ824rzG k2YcvaO3jN12B6d51/qRc1iqAOyCz9w/5igBEMxnvPP7CrQkOaBKpDUaCBnbxxQ4s/ F5WixNznQg7yOHqPGtqPl4wUUU6tkw2Sl6Y0mWVChw92iJAZ4Gnn6IhXQ6QI92r/ZI n1XAME+AgMzUQ== Date: Thu, 5 Jun 2025 09:41:44 -0500 From: "Rob Herring (Arm)" To: Aradhya Bhatia Cc: Devarsh Thakkar , Alexander Sverdlin , Devicetree List , Simona Vetter , Tomi Valkeinen , Thomas Zimmermann , Maxime Ripard , Michael Walle , Laurent Pinchart , Jyri Sarha , Vignesh Raghavendra , Conor Dooley , Francesco Dolcini , David Airlie , Maarten Lankhorst , Praneeth Bajjuri , Udit Kumar , Linux Kernel List , Jayesh Choudhary , Nishanth Menon , DRI Development List , Krzysztof Kozlowski Subject: Re: [PATCH v9 2/4] dt-bindings: display: ti: Add schema for AM625 OLDI Transmitter Message-ID: <174913450088.2539370.15860584421984514366.robh@kernel.org> References: <20250528122544.817829-1-aradhya.bhatia@linux.dev> <20250528122544.817829-3-aradhya.bhatia@linux.dev> 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: <20250528122544.817829-3-aradhya.bhatia@linux.dev> On Wed, 28 May 2025 17:55:42 +0530, Aradhya Bhatia wrote: > From: Aradhya Bhatia > > The OLDI transmitters (TXes) do not have registers of their own, and are > dependent on the source video-ports (VPs) from the DSS to provide > configuration data. This hardware doesn't directly sit on the internal > bus of the SoC, but does so via the DSS. Hence, the OLDI TXes are > supposed to be child nodes under the DSS, and not independent devices. > > Two of the OLDI TXes can function in tandem to output dual-link OLDI > output, or cloned single-link outputs. In these cases, one OLDI will be > the primary OLDI, and the other one, a companion. The following diagram > represents such a configuration. > > +-----+-----+ +-------+ > | | | | | > | | VP1 +----+--->+ OLDI0 | (Primary - may need companion) > | | | | | | > | DSS +-----+ | +-------+ > | | | | > | | VP2 | | +-------+ > | | | | | | > +-----+-----+ +--->+ OLDI1 | (Companion OLDI) > | | > +-------+ > > The DSS in AM625 SoC has a configuration like the one above. The AM625 > DSS VP1 (port@0) can connect and control 2 OLDI TXes, to use them in > dual-link or cloned single-link OLDI modes. It is only the VP1 that can > connect to either OLDI TXes for the AM625 DSS, and not the VP2. > > Alternatively, on some future TI SoCs, along with the above > configuration, the OLDI TX can _also_ connect to separate video sources, > making them work entirely independent of each other. In this case, > neither of the OLDIs are "companion" or "secondary" OLDIs, and nor do > they require one. They both are independent and primary OLDIs. The > following diagram represents such a configuration. > > +-----+-----+ +-------+ > | | | | | > | | VP1 +--+----------->+ OLDI0 | (Primary - may need companion) > | | | | | | > | +-----+ | +-------+ > | | | | > | | VP2 | | > | | | | > | DSS +-----+ | +---+ +-------+ > | | | +-->+ M | | | > | | VP3 +----->+ U +--->+ OLDI1 | (Companion or Primary) > | | | | X | | | > | +-----+ +---+ +-------+ > | | | > | | VP4 | > | | | > +-----+-----+ > > Note that depending on the mux configuration, the OLDIs can either be > working together in tandem - sourced by VP1, OR, they could be working > independently sourced by VP1 and VP3 respectively. > The idea is to support all the configurations with this OLDI TX schema. > > The OLDI functionality is further supported by a system-control module, > which contains a few registers to control OLDI IO power and other > electrical characteristics of the IO lanes. > > Add devicetree binding schema for the OLDI TXes to support various > configurations, and extend their support to the AM625 DSS. > > Signed-off-by: Aradhya Bhatia > Signed-off-by: Aradhya Bhatia > --- > Changes Log: > V9: > - Reword the "ti,companion-oldi" property description. > - Fix the missing "ti,companion-oldi" property in the schema example. > - v8 of this patch: https://lore.kernel.org/all/20250525151721.567042-3-aradhya.bhatia@linux.dev/ > > V8: > - Drop the condition that made the "secondary-oldi" and "companion-oldi" > properties mutually exclusive. > - Add "ti,am62l-dss" compatible to the list of compatibles that cannot > use the multiple endpoints or have "oldi-transmitters", on port@0. > - Because of above, drop R-b tags from Tomi Valkeinen, and Rob Herring. > - v7 of this patch: https://lore.kernel.org/all/20250329133943.110698-3-aradhya.bhatia@linux.dev/ > > --- > .../bindings/display/ti/ti,am625-oldi.yaml | 79 +++++++++ > .../bindings/display/ti/ti,am65x-dss.yaml | 157 ++++++++++++++++++ > MAINTAINERS | 1 + > 3 files changed, 237 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/ti/ti,am625-oldi.yaml > Reviewed-by: Rob Herring (Arm)