From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 09/19] drm: sun4i: Add DT bindings documentation Date: Fri, 6 Nov 2015 14:32:29 -0800 Message-ID: <20151106223229.GM6114@lukather> References: <1446214865-3972-1-git-send-email-maxime.ripard@free-electrons.com> <1446214865-3972-10-git-send-email-maxime.ripard@free-electrons.com> Reply-To: maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cO2ZlOvi7VNgmdOy" Return-path: Content-Disposition: inline In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Rob Herring Cc: Mike Turquette , Stephen Boyd , David Airlie , Thierry Reding , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel , linux-sunxi , Laurent Pinchart , Chen-Yu Tsai , Hans de Goede , Alexander Kaplan , Wynter Woods , Boris Brezillon , Thomas Petazzoni , Rob Clark , Daniel Vetter List-Id: devicetree@vger.kernel.org --cO2ZlOvi7VNgmdOy Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Hi Rob, On Fri, Oct 30, 2015 at 11:40:03AM -0500, Rob Herring wrote: > > +Display Engine Backend > > +---------------------- > > + > > +The display engine backend exposes layers and sprites to the > > +system. It's split into two components, the frontend and backend, the > > +frontend doing formats conversion, scaling, deinterlacing, while the > > +backend actually manages the layers. > > + > > +Required properties: > > + - compatible: value must be one of: > > + * allwinner,sun5i-a13-display-engine > > + > > + - reg: base address and size of the memory-mapped region. Two are needed: > > + * backend0: registers of the display engine backend > > + * frontend0: registers of the display engine frontend > > Why the zeros? I think they should be dropped. We have SoCs that have two backends and two frontends, hence why I added 0. I guess I can also add several devices for them, but then I'd need to move to the component framework I guess (which was the plan anyway). > > + > > + - allwinner,tcon: phandle to the TCON in our pipeline > > Use of-graph or just let the relationship live in the driver. If there > is only 1 instance of the blocks, the latter is fine. We can also have several TCON instances in the SoC, and even though you can on a theorical point of view use any TCON with any backend, usually you're tied because of how the pins are routed on the boards. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --cO2ZlOvi7VNgmdOy--