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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60F04C34024 for ; Mon, 17 Feb 2020 18:19:52 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 2229F208C4 for ; Mon, 17 Feb 2020 18:19:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="G8GBngld"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="kVCs+/i5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2229F208C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Z9T+wisofvL3ivHZk/NzQlzu4Z61xI+PiBQLraCSx84=; b=G8GBngld/Nj4XL 11+qFQK659U4dCrzJR/r9NhIxn/2W58v/vnNQOll6XsEpMJA/mTdXCAhpOS7LgVZSAtuIW6+m+QgD UxwqRzQSQ+7vpW/3RE33jVTrkpaboW0ZXgPI7iI6KKO/OR8T2qwi2SqQiDTwg2gKmg0eZWkPHPZoh vAZCwpBdJKVu4jTUv6jbdEEUqLv83pHWRCkfK7cZSZIf2npV0B8AdLHZTqW9XYE7NUl60/gkBRqR0 P9dQ9IC5NCm4VVWkoZkIkT+y93t0QK1OjAx1hBQnHjR6+2Cv/O2DkS3+tt6DztP4nUQSqcoy5SYce GoNhheZDlvpY3/013Rxg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3kzg-0000tA-Ua; Mon, 17 Feb 2020 18:19:44 +0000 Received: from perceval.ideasonboard.com ([2001:4b98:dc2:55:216:3eff:fef7:d647]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3kzd-0000sP-2I for linux-arm-kernel@lists.infradead.org; Mon, 17 Feb 2020 18:19:42 +0000 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B1DDC1170; Mon, 17 Feb 2020 19:10:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1581963026; bh=LGYbPge+pK4TDEOF3sR06MljT1AaTQKK51QITDjD0Pk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kVCs+/i5Nf8a+0zGj3upccoToJSu9p8u3ivFHBRadhN4iL2nQhJNoBXHV672rY3o1 jG2lTCpOryYQhy5snRE8bD9TA2r3ls+7jn+5nAP9uDAF0kiyE+rXTPY4I1VJnhQDID M++1Kyv+BqaaIwJGApOeTPOLhEUfTboaCsQ7FwB4= Date: Mon, 17 Feb 2020 20:10:06 +0200 From: Laurent Pinchart To: Maxime Ripard Subject: Re: [PATCH 1/2] dt-bindings: display: sun4i-tcon: Add LVDS Dual Link property Message-ID: <20200217181006.GE4830@pendragon.ideasonboard.com> References: <20200214123244.109300-1-maxime@cerno.tech> <20200214131025.GI4831@pendragon.ideasonboard.com> <20200214154405.f5zuicm6uhhiczfs@gilmour.lan> <20200214154953.GJ4831@pendragon.ideasonboard.com> <20200217174253.mj53us4bb7h2lyca@gilmour.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200217174253.mj53us4bb7h2lyca@gilmour.lan> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200217_101941_318820_EA806CAC X-CRM114-Status: GOOD ( 24.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, David Airlie , Maarten Lankhorst , dri-devel@lists.freedesktop.org, Chen-Yu Tsai , Rob Herring , Sean Paul , Daniel Vetter , Frank Rowand , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Maxime, On Mon, Feb 17, 2020 at 06:42:53PM +0100, Maxime Ripard wrote: > On Fri, Feb 14, 2020 at 05:49:53PM +0200, Laurent Pinchart wrote: > > On Fri, Feb 14, 2020 at 04:44:05PM +0100, Maxime Ripard wrote: > > > On Fri, Feb 14, 2020 at 03:10:25PM +0200, Laurent Pinchart wrote: > > > > On Fri, Feb 14, 2020 at 01:32:43PM +0100, Maxime Ripard wrote: > > > > > SoCs that have multiple TCONs can use the two set of pins on the first TCON > > > > > to drive a dual-link display. Add a property to enable the dual link. > > > > > > > > > > Signed-off-by: Maxime Ripard > > > > > --- > > > > > .../bindings/display/allwinner,sun4i-a10-tcon.yaml | 7 +++++++ > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml b/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > index 86ad617d2327..aa6dd8409dbc 100644 > > > > > --- a/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > +++ b/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > @@ -105,6 +105,13 @@ properties: > > > > > - const: edp > > > > > - const: lvds > > > > > > > > > > + allwinner,lvds-dual-link: > > > > > + type: boolean > > > > > + description: | > > > > > + On a SoC with two TCON with LVDS support, the first TCON can > > > > > + operate over both pins sets to output in a dual-link setup. This > > > > > + will be triggered by setting this property. > > > > > > > > Could you maybe provide an example of how this property is supposed to > > > > be used ? I'm especially wondering what ports are used in that case and > > > > how they're connected. > > > > > > It's pretty trivial to support, it's only a property to set on the > > > encoder node itself. > > > > > > I'm not really sure what you meant by your question with the ports > > > though :/ > > > > I assume that, in the single-link case, you have two TCON instances that > > operate independently, each of them with one port that models an LVDS > > connection to a panel. > > Indeed, > > > In the dual-link mode, how does that look like ? Does the TCON > > instance that operate in dual-link mode have two ports in DT ? There > > are two physical ports, so I think it makes sense to always have two > > ports in DT. That's what we're doing for the LVDS encoders on R-Car > > Gen3, in order to specify in DT which LVDS input of the dual-link > > panel is connected to which LVDS output of the SoC. That allows > > configuring the LVDS encoder to send the even and odd pixels on the > > right port. > > As far as I can tell, you can't control that in our TCON. It just on > more lanes, that's it. Also, we currently have multiple ports, to map > another feature of the TCON, which is that it can drive directly a > panel, or will send its output to the HDMI / TV encoders. Adding > another port in that will break the current binding we have. This will create one issue though, in that the dual-link sinks are supposed to have two input ports, in order to expose the odd and even pixels ordering. If you have a single ouput port in your TCON, how will you interface with such sinks ? -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel