Re: [PATCH v3 1/8] dt-bindings: display: Add bindings for LVDS bus-timings

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Cc: David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	DRI Development <dri-devel@lists.freedesktop.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Simon Horman <horms@verge.net.au>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	Jacopo Mondi <jacopo+renesas@jmondi.org>,
	Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [PATCH v3 1/8] dt-bindings: display: Add bindings for LVDS bus-timings
Date: Thu, 29 Aug 2019 09:57:35 +0200	[thread overview]
Message-ID: <CAMuHMdVPsT=1R7DAnmui+iaWcnoy52Xrr47zLWbgmUumBZ2sdw@mail.gmail.com> (raw)
In-Reply-To: <1567017402-5895-2-git-send-email-fabrizio.castro@bp.renesas.com>

Hi Fabrizio,

On Wed, Aug 28, 2019 at 8:36 PM Fabrizio Castro
<fabrizio.castro@bp.renesas.com> wrote:
> Dual-LVDS connections need markers in the DT, this patch adds
> some common documentation to be referenced by both panels and
> bridges.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>

Thanks for your patch!

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bus-timings/lvds.yaml
> @@ -0,0 +1,38 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bus-timings/lvds.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common Properties for bus timings of LVDS interfaces
> +
> +maintainers:
> +  - Thierry Reding <thierry.reding@gmail.com>
> +  - Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> +
> +description: |
> +  This document defines device tree properties common to LVDS and dual-LVDS
> +  interfaces, where a dual-LVDS interface is a dual-link connection with even
> +  pixels traveling on one connection, and with odd pixels traveling on the other
> +  connection.
> +  This document doesn't constitue a device tree binding specification by itself
> +  but is meant to be referenced by device tree bindings.
> +  When referenced from panel or bridge device tree bindings, the properties
> +  defined in this document are defined as follows. The panel and bridge device
> +  tree bindings are responsible for defining whether each property is required
> +  or optional.
> +
> +properties:
> +  dual-lvds-even-pixels:
> +    type: boolean
> +    description:
> +      This property is specific to an input port of a sink device. When
> +      specified, it marks the port as recipient of even-pixels.
> +
> +  dual-lvds-odd-pixels:
> +    type: boolean
> +    description:
> +      This property is specific to an input port of a sink device. When
> +      specified, it marks the port as recipient of odd-pixels.

Do you need the "dual-" prefix? Isn't that implied by even/odd?
Or is it better to keep it, for readability?

I'm also thinking about a possible future extension to triple or quad LVDS.
As I'm not aware of English word equivalents of even/odd for triple/quad,
perhaps this should be specified using a numerical value instead?

If I go too far, please just say so ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds