On Mon, Feb 17, 2020 at 08:10:06PM +0200, Laurent Pinchart wrote: > Hi Maxime, > > On Mon, Feb 17, 2020 at 06:42:53PM +0100, Maxime Ripard wrote: > > On Fri, Feb 14, 2020 at 05:49:53PM +0200, Laurent Pinchart wrote: > > > On Fri, Feb 14, 2020 at 04:44:05PM +0100, Maxime Ripard wrote: > > > > On Fri, Feb 14, 2020 at 03:10:25PM +0200, Laurent Pinchart wrote: > > > > > On Fri, Feb 14, 2020 at 01:32:43PM +0100, Maxime Ripard wrote: > > > > > > SoCs that have multiple TCONs can use the two set of pins on the first TCON > > > > > > to drive a dual-link display. Add a property to enable the dual link. > > > > > > > > > > > > Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> > > > > > > --- > > > > > > .../bindings/display/allwinner,sun4i-a10-tcon.yaml | 7 +++++++ > > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml b/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > > index 86ad617d2327..aa6dd8409dbc 100644 > > > > > > --- a/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > > +++ b/Documentation/devicetree/bindings/display/allwinner,sun4i-a10-tcon.yaml > > > > > > @@ -105,6 +105,13 @@ properties: > > > > > > - const: edp > > > > > > - const: lvds > > > > > > > > > > > > + allwinner,lvds-dual-link: > > > > > > + type: boolean > > > > > > + description: | > > > > > > + On a SoC with two TCON with LVDS support, the first TCON can > > > > > > + operate over both pins sets to output in a dual-link setup. This > > > > > > + will be triggered by setting this property. > > > > > > > > > > Could you maybe provide an example of how this property is supposed to > > > > > be used ? I'm especially wondering what ports are used in that case and > > > > > how they're connected. > > > > > > > > It's pretty trivial to support, it's only a property to set on the > > > > encoder node itself. > > > > > > > > I'm not really sure what you meant by your question with the ports > > > > though :/ > > > > > > I assume that, in the single-link case, you have two TCON instances that > > > operate independently, each of them with one port that models an LVDS > > > connection to a panel. > > > > Indeed, > > > > > In the dual-link mode, how does that look like ? Does the TCON > > > instance that operate in dual-link mode have two ports in DT ? There > > > are two physical ports, so I think it makes sense to always have two > > > ports in DT. That's what we're doing for the LVDS encoders on R-Car > > > Gen3, in order to specify in DT which LVDS input of the dual-link > > > panel is connected to which LVDS output of the SoC. That allows > > > configuring the LVDS encoder to send the even and odd pixels on the > > > right port. > > > > As far as I can tell, you can't control that in our TCON. It just on > > more lanes, that's it. Also, we currently have multiple ports, to map > > another feature of the TCON, which is that it can drive directly a > > panel, or will send its output to the HDMI / TV encoders. Adding > > another port in that will break the current binding we have. > > This will create one issue though, in that the dual-link sinks are > supposed to have two input ports, in order to expose the odd and even > pixels ordering. If you have a single ouput port in your TCON, how will > you interface with such sinks ? I guess we could create multiple endpoints in the same port? That's not going to be trivial either though given the current binding we have :/ Maxime
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