[PATCH v2] dt-bindings: drm: rcar-du: Document optional reset properties

[Rob Herring]

On Thu, Mar 16, 2017 at 09:59:04PM +0100, Geert Uytterhoeven wrote:
> Hi Rob,
> 
> On Thu, Mar 16, 2017 at 9:56 PM, Rob Herring <robh at kernel.org> wrote:
> > On Thu, Mar 16, 2017 at 09:13:16AM +0100, Geert Uytterhoeven wrote:
> >> On Wed, Mar 15, 2017 at 6:01 PM, Rob Herring <robh at kernel.org> wrote:
> >> > On Mon, Mar 06, 2017 at 05:25:56PM +0100, Geert Uytterhoeven wrote:
> >> >> Document the optional properties for describing module resets, to
> >> >> support resetting display channels and LVDS encoders on R-Car Gen2 and
> >> >> Gen3.
> >> >>
> >> >> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
> >> >> ---
> >> >> See "[v2,1/4] dt-bindings: clock: renesas: cpg-mssr: Document reset control
> >> >> support" (https://patchwork.kernel.org/patch/9536627/) for the format of
> >> >> a reset specifier in the Renesas CPG/MSSR case.
> >> >>
> >> >> E.g. "resets = <&cpg 310>;"
> >> >>
> >> >> v2:
> >> >>   - s/phandles/phandle/.
> >> >> ---
> >> >>  Documentation/devicetree/bindings/display/renesas,du.txt | 10 ++++++++++
> >> >>  1 file changed, 10 insertions(+)
> >> >>
> >> >> diff --git a/Documentation/devicetree/bindings/display/renesas,du.txt b/Documentation/devicetree/bindings/display/renesas,du.txt
> >> >> index 1a02f099a0ff0a3a..3db418c827193e82 100644
> >> >> --- a/Documentation/devicetree/bindings/display/renesas,du.txt
> >> >> +++ b/Documentation/devicetree/bindings/display/renesas,du.txt
> >> >> @@ -36,6 +36,16 @@ Required Properties:
> >> >>        When supplied they must be named "dclkin.x" with "x" being the input
> >> >>        clock numerical index.
> >> >>
> >> >> +Optional properties:
> >> >> +  - resets: A list of phandle + reset-specifier pairs, one for each entry in
> >> >> +    the reset-names property.
> >> >> +  - reset-names: Names of the resets. This property is model-dependent.
> >> >> +    - R8A779[0123456] use one reset for a group of one or more successive
> >> >> +      channels, and one reset per LVDS encoder (if available). The resets
> >> >> +      must be named "du.x" with "x" being the numerical index of the lowest
> >> >> +      channel in the group. The LVDS resets must be named "lvds.x" with "x"
> >> >> +      being the LVDS encoder numerical index.
> >> >
> >> > LVDS is not a separate block?
> >>
> >> Well... from a hardware point of view, the LVDS encoders and DU channels
> >> are all separate blocks (they have separate reg blocks, clocks, and resets).
> >> But due to the dependencies between the blocks, they're modeled in DT as
> >> a single device, with multiple reg, clocks, and resets properties.
> >
> > Dependencies being DRM requirement of wanting a single device with
> > sub-devices or some h/w dependencies? The former shouldn't define your
> > binding.
> 
> Hardware dependencies. Laurent can tell you more about them (when he'll
> be back).

Okay,

Acked-by: Rob Herring <robh at kernel.org>

Rob