Hi, On Fri, Apr 28, 2017 at 08:48:41AM -0500, Rob Herring wrote: > On Fri, Apr 21, 2017 at 04:38:49PM +0800, Chen-Yu Tsai wrote: > > The Allwinner display pipeline contains many hardware components, some > > of which can consume data from one of multiple upstream components. > > The numbering scheme of these components must be encoded into the device > > tree so the driver can figure out which component out of two or more of > > the same type it is supposed to use or program. > > > > This patch adds the constraint that local endpoint IDs must be the index > > or number of the remote endpoint's hardware block, for all components > > in the display pipeline up to the TCONs. > > > > Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> > > --- > > Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt > > index 57a8d0610062..7acdbf14ae1c 100644 > > --- a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt > > +++ b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt > > @@ -4,6 +4,16 @@ Allwinner A10 Display Pipeline > > The Allwinner A10 Display pipeline is composed of several components > > that are going to be documented below: > > > > +For the input port of all components up to the TCON in the display > > +pipeline, if there are multiple components, the local endpoint IDs > > +must correspond to the index of the upstream block. For example, if > > +the remote endpoint is Frontend 1, then the local endpoint ID must > > +be 1. > > + > > +Conversely, for the output ports of the same group, the remote endpoint > > +ID must be the index of the local hardware block. If the local backend > > +is backend 1, then the remote endpoint ID must be 1. > > It would be clearer if you just explicitly listed IDs and their > connections. From how this is worded, it would not work if you had > connections like this: > > DevA 0 > DevA 1 > DevB 0 > DevB 1 > > These would need to be endpoints 0-3 in TCON, and that doesn't reflect > the remote devices' index. Chen-Yu, can you send a patch to rephrase the doc that way? Thanks, Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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