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 403B31E5B65; Wed, 19 Feb 2025 14:22:41 +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=1739974962; cv=none; b=IRhZJNrrnvk/YyRqZKqzTpoJ+jm79gYzQXdg50j327rPzLtjNqDzUHNxWKClwoPU193MT5i6C6Oag1Y+Wu/OFPOLi9/+/l6kUm211VbuI49xzUa8VvGPqYYTK9+v3H4oo3ZgDnq0qa7wpsUIUf6z5ZPzKSqW6xblCbFYHiPUrNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739974962; c=relaxed/simple; bh=L9cXmlOzsS72RtfjvOGSFezFI8Z+PKWtlvupHDV8mXw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Lb3a5ihd+fMubYOMpZUa5cUTuZn53cyUx4IBxS/iqypzcNrGiChPw39GVMugZFaNPbKTEYzTP6hJuQJm/tUE8qFwAyDwEDUVaIqhEDJQC+hpNbpnrJjqsuqU9gqwPq4RVsWRkvZz1wA4q14U7vghyhRkrXc6oYe/8xpimIwgwrE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uzVFdQA1; 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="uzVFdQA1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8078AC4CEE0; Wed, 19 Feb 2025 14:22:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739974961; bh=L9cXmlOzsS72RtfjvOGSFezFI8Z+PKWtlvupHDV8mXw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uzVFdQA1Km9wft+L5wvygubV3B/Fz2QcpdIz+JXKjuuFKnitm6lsvXeidMhpBV0LQ JK7WsHfxN8G2YeOy5B+9gUafcBqnx9y+tYC8QTMCkx3oDabU8J2PwGuLciLpoTljGi gJ2Q5aCQBqTYAs6WoDUu08uUDQgR/mbz9D7iLK4Gu0fEoFGiZAqW1Lx+RYPlqEvgJI y/xh4EDCHkbz5JvAxxpBrpg6l4iuwb1aVlZU2jLWIfQxcryta/MKtPr3q6ZMKGzGLz 8dL1VqT+19PvE3dY40ZyWWFPkALgUxwWrBUdbR75savI5R5YgGRmUeyjJ9krfrBvnQ FB6wgG5Bc48ow== Date: Wed, 19 Feb 2025 08:22:40 -0600 From: "Rob Herring (Arm)" To: Aradhya Bhatia Cc: Linux Kernel List , Jayesh Choudhary , Vignesh Raghavendra , Maarten Lankhorst , Krzysztof Kozlowski , Francesco Dolcini , Nishanth Menon , Thomas Zimmermann , Praneeth Bajjuri , Maxime Ripard , Tomi Valkeinen , Udit Kumar , Devicetree List , Devarsh Thakkar , Laurent Pinchart , Conor Dooley , David Airlie , Jyri Sarha , DRI Development List , Simona Vetter Subject: Re: [PATCH v5 2/3] dt-bindings: display: ti: Add schema for AM625 OLDI Transmitter Message-ID: <173997495988.2526899.9124442481347234668.robh@kernel.org> References: <20250209160925.380348-1-aradhya.bhatia@linux.dev> <20250209160925.380348-3-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: <20250209160925.380348-3-aradhya.bhatia@linux.dev> On Sun, 09 Feb 2025 21:39:24 +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 > --- > .../bindings/display/ti/ti,am625-oldi.yaml | 88 ++++++++++ > .../bindings/display/ti/ti,am65x-dss.yaml | 154 ++++++++++++++++++ > MAINTAINERS | 1 + > 3 files changed, 243 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/ti/ti,am625-oldi.yaml > Reviewed-by: Rob Herring (Arm)