linux-kernel - Re: [PATCH 09/19] drm: sun4i: Add DT bindings documentation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20151106223229.GM6114@lukather>
Date:	Fri, 6 Nov 2015 14:32:29 -0800
From:	Maxime Ripard <maxime.ripard@...e-electrons.com>
To:	Rob Herring <robh@...nel.org>
Cc:	Mike Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	David Airlie <airlied@...ux.ie>,
	Thierry Reding <thierry.reding@...il.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	linux-clk@...r.kernel.org,
	dri-devel <dri-devel@...ts.freedesktop.org>,
	linux-sunxi <linux-sunxi@...glegroups.com>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Chen-Yu Tsai <wens@...e.org>,
	Hans de Goede <hdegoede@...hat.com>,
	Alexander Kaplan <alex@...tthing.co>,
	Wynter Woods <wynter@...tthing.co>,
	Boris Brezillon <boris.brezillon@...e-electrons.com>,
	Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
	Rob Clark <robdclark@...il.com>,
	Daniel Vetter <daniel@...ll.ch>
Subject: Re: [PATCH 09/19] drm: sun4i: Add DT bindings documentation

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

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)