| Message ID | 20190306232345.23052-8-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | R-Car DU: LVDS dual-link mode support | expand |
Hi Laurent, On Thu, Mar 7, 2019 at 12:24 AM Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> wrote: > Add a new optional renesas,companion property to point to the companion > LVDS encoder. This is used to support dual-link operation where the main > LVDS encoder splits even-numbered and odd-numbered pixels between the > two LVDS encoders. Note that Documentation/devicetree/bindings/usb/generic.txt already describes a "companion" property without vendor prefix. > The new property doesn't control the mode of operation, it only > describes the relationship between the master and companion LVDS > encoders. > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > --- > .../devicetree/bindings/display/bridge/renesas,lvds.txt | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > index 900a884ad9f5..a720dbb5de69 100644 > --- a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > +++ b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > @@ -45,6 +45,12 @@ OF graph bindings specified in Documentation/devicetree/bindings/graph.txt. > > Each port shall have a single endpoint. > > +Optional properties: > + > +- renesas,companion : phandle to the companion LVDS encoder. This property is > + valid for the first LVDS encoder D3 and E3 SoCs only, and points to the ... on D3 ... > + second encoder to be used as a companion in dual-link mode. Why restrict this to the first LVDS decoder, and not have a backlink in the other node, like for USB? Gr{oetje,eeting}s, Geert
Hi Geert, On Mon, Mar 18, 2019 at 11:21:15AM +0100, Geert Uytterhoeven wrote: > On Thu, Mar 7, 2019 at 12:24 AM Laurent Pinchart wrote: > > Add a new optional renesas,companion property to point to the companion > > LVDS encoder. This is used to support dual-link operation where the main > > LVDS encoder splits even-numbered and odd-numbered pixels between the > > two LVDS encoders. > > Note that Documentation/devicetree/bindings/usb/generic.txt already > describes a "companion" property without vendor prefix. > > > The new property doesn't control the mode of operation, it only > > describes the relationship between the master and companion LVDS > > encoders. > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > --- > > .../devicetree/bindings/display/bridge/renesas,lvds.txt | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > > index 900a884ad9f5..a720dbb5de69 100644 > > --- a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > > +++ b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt > > @@ -45,6 +45,12 @@ OF graph bindings specified in Documentation/devicetree/bindings/graph.txt. > > > > Each port shall have a single endpoint. > > > > +Optional properties: > > + > > +- renesas,companion : phandle to the companion LVDS encoder. This property is > > + valid for the first LVDS encoder D3 and E3 SoCs only, and points to the > > ... on D3 ... > > > + second encoder to be used as a companion in dual-link mode. > > Why restrict this to the first LVDS decoder, and not have a backlink in the > other node, Because there's no need to ? :-) Furthermore there's a need for the master to know its a master, so have a link in a single direction is pretty convenient. Otherwise I'd need an extra property to identify the master. > like for USB? I'm not sure what USB does in that regard.
diff --git a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt index 900a884ad9f5..a720dbb5de69 100644 --- a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt +++ b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt @@ -45,6 +45,12 @@ OF graph bindings specified in Documentation/devicetree/bindings/graph.txt. Each port shall have a single endpoint. +Optional properties: + +- renesas,companion : phandle to the companion LVDS encoder. This property is + valid for the first LVDS encoder D3 and E3 SoCs only, and points to the + second encoder to be used as a companion in dual-link mode. + Example:
Add a new optional renesas,companion property to point to the companion LVDS encoder. This is used to support dual-link operation where the main LVDS encoder splits even-numbered and odd-numbered pixels between the two LVDS encoders. The new property doesn't control the mode of operation, it only describes the relationship between the master and companion LVDS encoders. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- .../devicetree/bindings/display/bridge/renesas,lvds.txt | 6 ++++++ 1 file changed, 6 insertions(+)