From: Sam Ravnborg <sam@ravnborg.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: devicetree@vger.kernel.org, Jacopo Mondi <jacopo@jmondi.org>,
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
dri-devel@lists.freedesktop.org,
linux-renesas-soc@vger.kernel.org,
Jacopo Mondi <jacopo+renesas@jmondi.org>
Subject: Re: [PATCH v3 04/10] dt-bindings: display: renesas: lvds: Add renesas, companion property
Date: Tue, 28 May 2019 18:59:00 +0200 [thread overview]
Message-ID: <20190528165900.GA10262@ravnborg.org> (raw)
In-Reply-To: <20190528164916.GA17874@pendragon.ideasonboard.com>
Hi Laurent.
> > >
> > > +Optional properties:
> > > +
> > > +- renesas,companion : phandle to the companion LVDS encoder. This property is
> > > + mandatory for the first LVDS encoder on D3 and E3 SoCs, and shall point to
> > > + the second encoder to be used as a companion in dual-link mode. It shall not
> > > + be set for any other LVDS encoder.
> >
> > If the D3 and E3 socs do not mandate the use of dual-link, then what to
> > do in the DT? Because according to the above this property must be
> > specified for D3 and E3 SOC's.
>
> This property doesn't enable dual-link mode, it only specifies the
> companion LVDS encoder used for dual-link mode, when enabled (through
> communication between the LVDS encoder and the LVDS receiver at
> runtime).
>
> Jacopo had a similar comment so I suppose this isn't clear. How would
> you word it to make it clear ?
Let me try:
- renesas,companion : phandle to the companion LVDS encoder. This property is
mandatory for the first LVDS encoder on D3 and E3 SoCs when dual-link mode
is supported.
The property shall pont to the phandle of the second encoder to be used as a
companion in dual-link mode. It shall not be set for any other LVDS encoder.
The main difference is "when dual-link mode is supported".
As per my understanding this property is only relevant when the actual
HW supports / uses dual-link mode.
So for a board that do not even wire up dual-link, then setting the
property would be confusing.
I hope this better describes my understanding.
Sam
next prev parent reply other threads:[~2019-05-28 16:59 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-28 14:12 [PATCH v3 00/10] R-Car DU: LVDS dual-link mode support Laurent Pinchart
2019-05-28 14:12 ` [PATCH v3 01/10] drm: bridge: Add dual_link field to the drm_bridge_timings structure Laurent Pinchart
2019-07-30 12:12 ` Neil Armstrong
2019-05-28 14:12 ` [PATCH v3 02/10] dt-bindings: display: bridge: thc63lvd1024: Document dual-link operation Laurent Pinchart
2019-06-07 22:15 ` Kieran Bingham
2019-06-07 22:30 ` Laurent Pinchart
2019-06-07 22:36 ` Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 03/10] drm: bridge: thc63: Report input bus mode through bridge timings Laurent Pinchart
2019-06-07 22:51 ` Kieran Bingham
2019-07-30 12:13 ` Neil Armstrong
2019-05-28 14:12 ` [PATCH v3 04/10] dt-bindings: display: renesas: lvds: Add renesas,companion property Laurent Pinchart
2019-05-28 16:37 ` [PATCH v3 04/10] dt-bindings: display: renesas: lvds: Add renesas, companion property Sam Ravnborg
2019-05-28 16:49 ` Laurent Pinchart
2019-05-28 16:59 ` Sam Ravnborg [this message]
2019-06-06 7:54 ` Laurent Pinchart
2019-06-06 9:27 ` Sam Ravnborg
2019-06-07 22:33 ` [PATCH v3 04/10] dt-bindings: display: renesas: lvds: Add renesas,companion property Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 05/10] drm: rcar-du: lvds: Remove LVDS double-enable checks Laurent Pinchart
2019-06-07 22:09 ` Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 06/10] drm: rcar-du: lvds: Add support for dual-link mode Laurent Pinchart
2019-06-07 23:11 ` Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 07/10] drm: rcar-du: Skip LVDS1 output on Gen3 when using dual-link LVDS mode Laurent Pinchart
2019-05-28 16:42 ` Sam Ravnborg
2019-05-28 16:50 ` Laurent Pinchart
2019-05-28 17:02 ` Sam Ravnborg
2019-06-06 7:57 ` Laurent Pinchart
2019-06-06 9:29 ` Sam Ravnborg
2019-06-07 23:19 ` Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 08/10] arm64: dts: renesas: r8a7799[05]: Point LVDS0 to its companion LVDS1 Laurent Pinchart
2019-06-03 11:40 ` Simon Horman
2019-06-06 7:59 ` Laurent Pinchart
2019-06-06 8:51 ` Simon Horman
2019-06-12 10:21 ` Laurent Pinchart
2019-06-12 11:52 ` Simon Horman
2019-06-07 23:15 ` Kieran Bingham
2019-05-28 14:12 ` [PATCH v3 09/10] [HACK] arm64: dts: renesas: draak: Enable LVDS dual-link operation Laurent Pinchart
2019-05-28 14:12 ` [PATCH v3 10/10] [HACK] arm64: dts: renesas: ebisu: " Laurent Pinchart
2019-07-22 11:27 ` Fabrizio Castro
2019-07-23 10:30 ` Jacopo Mondi
2019-07-23 12:16 ` Fabrizio Castro
2019-05-28 16:46 ` [PATCH v3 00/10] R-Car DU: LVDS dual-link mode support Sam Ravnborg
2019-06-07 22:16 ` Kieran Bingham
2019-06-07 22:21 ` Laurent Pinchart
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