From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 52FC5371D02; Mon, 15 Jun 2026 11:06:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781521578; cv=none; b=BVz+CLgytrEwxm4auEhcDHXs0bEmcl+PEqZ91MGDUO0dDgBR1gnbyCn5LUG+P2Rv1c8O25DmPGmeN8pVinA6aUEigcDtmfvLvqsHhO2eJTUSI99vF0LHsba4AWL3Jxvqk3MNmjNIXznBpU3/7UvrPqIcV7X5aiJv8bzgKC12jgM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781521578; c=relaxed/simple; bh=ZKByL8sIB9khjZZ1TUk0OL6t+PRiVXvN+5s/ImffJBI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gAwxVAg3YKM1NV7qpHA+dQsbF6pMV/vQQFlhBrVaUdU4jxfjzwU3BWm/bS4OINwCBRWlRdETlkNwIi4IYmND1Bxq4i4dcc5wmCGo2jS894EQz8WPMh3sivv796zQB1cp5qrdkuDgGjqi/jciClzatCXANAF6NxUzVgt+RlYves0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=FthRFMEl; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="FthRFMEl" Received: from [192.168.88.20] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B80A119DC; Mon, 15 Jun 2026 13:05:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1781521540; bh=ZKByL8sIB9khjZZ1TUk0OL6t+PRiVXvN+5s/ImffJBI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FthRFMElHZZvDVqh9YrWQfdOKxPN0jbC5Ad1wKd/HyHknKZGFaY2xX065HhvIshJG 3QrnGmwXybKHKzN1LdB9JTRVuAcKI4rqSqAojMUkE1DGHzhe5qbCwWYtXTMOpQiIPO Q0RgNvA+8m0+T5g2k/X9jYGppdtNbG+gE+5rAlTQ= Message-ID: <27ff2472-5e71-4af1-98fd-7b8142ad14c5@ideasonboard.com> Date: Mon, 15 Jun 2026 14:06:08 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/7] dt-bindings: display: bridge: Document Renesas R-Car V4H DSC bindings To: Geert Uytterhoeven , Tomi Valkeinen Cc: Michael Turquette , Stephen Boyd , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Magnus Damm , Marek Vasut , Laurent Pinchart , Kieran Bingham , Philipp Zabel , linux-renesas-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, Conor Dooley References: <20260615-rcar-du-dsc-v4-0-93096a1b56a3@ideasonboard.com> <20260615-rcar-du-dsc-v4-2-93096a1b56a3@ideasonboard.com> From: Tomi Valkeinen Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Geert, On 15/06/2026 12:24, Geert Uytterhoeven wrote: > Hi Tomi, > > On Mon, 15 Jun 2026 at 08:28, Tomi Valkeinen > wrote: >> From: Marek Vasut >> >> The Renesas DSC Display Stream Compression is a bridge embedded in the >> Renesas R-Car V4H SoC. The bridge performs VESA DSC encoding of up to >> 8k or 400 Mpixel/s . >> >> Signed-off-by: Marek Vasut >> [tomi.valkeinen: fix the example] >> Signed-off-by: Tomi Valkeinen >> Reviewed-by: Laurent Pinchart >> Acked-by: Conor Dooley > > Thanks for the update! > >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/display/bridge/renesas,dsc.yaml >> @@ -0,0 +1,99 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$id: http://devicetree.org/schemas/display/bridge/renesas,dsc.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: Renesas R-Car DSC Display Stream Compression >> + >> +maintainers: >> + - Marek Vasut >> + >> +description: | >> + This binding describes the VESA DSC Display Stream Compression encoder >> + embedded in the Renesas R-Car V4H SoC. The encoder supports all DSC1.1 >> + encoding mechanisms, configurable bits-per-pixel, resolution up to 8k. >> + >> +properties: >> + compatible: >> + items: >> + - enum: >> + - renesas,r8a779g0-dsc >> + - const: renesas,rcar-dsc > > Please do not introduce new "renesas,rcar" fallback compatible values, > unless you are adding new support for a hardware block that is present > in SoCs belonging to multiple (nowadays I would say at least three) > R-Car generations. The DSC is only found in R-Car Gen4 SoCs, so > "renesas,rcar-gen4-dsc" sounds more appropriate. Ok. > However, so far R-Car V4H is the only R-Car Gen4 SoC that has a DSC. Right. Even "renesas,rcar-gen4-dsc" feels a bit too wide. None of the other rcar du related bindings define fallback compatibles. So maybe we can just keep "renesas,r8a779g0-dsc" and name the file "renesas,r8a779g0-dsc.yaml" (which was the review comment I'm trying to resolve with this change). > Even the very similar R-Car V4M does not seem to have it. > R-Car X5H has DSC-functionality integrated in its DisplayPort TX > controller, so that seems to be a different implementation? I'm not that familiar with DSC functionality, but my understanding is that it's not DSI or DP specific, it just outputs packed parallel video. I couldn't find details about X5H's DSC, it could even be the same block (or not). Tomi