[RFC,1/9] dt-bindings: display: renesas,cmm: Add R-Car CMM documentation
diff mbox series

Message ID 20190508173428.22054-2-jacopo+renesas@jmondi.org
State New
Delegated to: Kieran Bingham
Headers show
Series
  • drm: rcar-du: Add CMM support to M3-W (plumbing only)
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Commit Message

Jacopo Mondi May 8, 2019, 5:34 p.m. UTC
Add device tree bindings documentation for the Renesas R-Car Display
Unit Color Management Module.

CMM is the image enhancement module available on each R-Car DU video
channel.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 .../bindings/display/renesas,cmm.txt          | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.txt

Comments

Laurent Pinchart May 11, 2019, 6:16 p.m. UTC | #1
Hi Jacopo,

Thank you for the patch.

On Wed, May 08, 2019 at 07:34:20PM +0200, Jacopo Mondi wrote:
> Add device tree bindings documentation for the Renesas R-Car Display
> Unit Color Management Module.
> 
> CMM is the image enhancement module available on each R-Car DU video
> channel.

Not on all of them, V3M and V3H don't include a CMM module.

> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
>  .../bindings/display/renesas,cmm.txt          | 24 +++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/renesas,cmm.txt b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> new file mode 100644
> index 000000000000..d7674417edb4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> @@ -0,0 +1,24 @@
> +* Renesas R-Car Color Management Unit (CMM)

It's called Color Management Module in the documentation (hence the CMM
abbreviation)

> +
> +Renesas R-Car image enhancement module connected to R-Car DU video channels.
> +
> +Required properties:
> + - compatible: shall be:
> +   - "renesas,cmm"

There's a CMM in R-Car Gen2 with a different feature set, so I think you
need at least two compatible strings. As far as I can tell SoC-specific
compatible strings are required.

> +
> + - reg: the address base and length of the memory area where CMM control
> +   registers are mapped to.
> +
> + - clocks: phandle and clock-specifier pair to the CMM functional clock
> +   supplier.
> +
> +Example:
> +--------
> +
> +	cmm0: cmm@fea40000 {
> +		compatible = "renesas,cmm";
> +		reg = <0 0xfea40000 0 0x1000>;
> +		power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
> +		clocks = <&cpg CPG_MOD 711>;
> +		resets = <&cpg 711>;
> +	};
Jacopo Mondi May 28, 2019, 12:37 p.m. UTC | #2
Hi Laurent,

On Sat, May 11, 2019 at 09:16:18PM +0300, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Wed, May 08, 2019 at 07:34:20PM +0200, Jacopo Mondi wrote:
> > Add device tree bindings documentation for the Renesas R-Car Display
> > Unit Color Management Module.
> >
> > CMM is the image enhancement module available on each R-Car DU video
> > channel.
>
> Not on all of them, V3M and V3H don't include a CMM module.
>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  .../bindings/display/renesas,cmm.txt          | 24 +++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.txt
> >
> > diff --git a/Documentation/devicetree/bindings/display/renesas,cmm.txt b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> > new file mode 100644
> > index 000000000000..d7674417edb4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> > @@ -0,0 +1,24 @@
> > +* Renesas R-Car Color Management Unit (CMM)
>
> It's called Color Management Module in the documentation (hence the CMM
> abbreviation)
>
> > +
> > +Renesas R-Car image enhancement module connected to R-Car DU video channels.
> > +
> > +Required properties:
> > + - compatible: shall be:
> > +   - "renesas,cmm"
>
> There's a CMM in R-Car Gen2 with a different feature set, so I think you
> need at least two compatible strings. As far as I can tell SoC-specific
> compatible strings are required.

I assume you meant "SoC-specific compatible strings are NOT required" ?

Could you otherwise specify why do you think we need a per-SoC
compatible, since there are no platform specific data (for now, at
least, but considering the CMM seems identical in all SoCs I hardly
think we will have any in the near future).

Ack on the gen2/gen3 specific strings though.

Thanks
   j


>
> > +
> > + - reg: the address base and length of the memory area where CMM control
> > +   registers are mapped to.
> > +
> > + - clocks: phandle and clock-specifier pair to the CMM functional clock
> > +   supplier.
> > +
> > +Example:
> > +--------
> > +
> > +	cmm0: cmm@fea40000 {
> > +		compatible = "renesas,cmm";
> > +		reg = <0 0xfea40000 0 0x1000>;
> > +		power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
> > +		clocks = <&cpg CPG_MOD 711>;
> > +		resets = <&cpg 711>;
> > +	};
>
> --
> Regards,
>
> Laurent Pinchart
Laurent Pinchart May 28, 2019, 2:25 p.m. UTC | #3
Hi Jacopo,

On Tue, May 28, 2019 at 02:37:25PM +0200, Jacopo Mondi wrote:
> On Sat, May 11, 2019 at 09:16:18PM +0300, Laurent Pinchart wrote:
> > On Wed, May 08, 2019 at 07:34:20PM +0200, Jacopo Mondi wrote:
> >> Add device tree bindings documentation for the Renesas R-Car Display
> >> Unit Color Management Module.
> >>
> >> CMM is the image enhancement module available on each R-Car DU video
> >> channel.
> >
> > Not on all of them, V3M and V3H don't include a CMM module.
> >
> >> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >> ---
> >>  .../bindings/display/renesas,cmm.txt          | 24 +++++++++++++++++++
> >>  1 file changed, 24 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/display/renesas,cmm.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/display/renesas,cmm.txt b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> >> new file mode 100644
> >> index 000000000000..d7674417edb4
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> >> @@ -0,0 +1,24 @@
> >> +* Renesas R-Car Color Management Unit (CMM)
> >
> > It's called Color Management Module in the documentation (hence the CMM
> > abbreviation)
> >
> >> +
> >> +Renesas R-Car image enhancement module connected to R-Car DU video channels.
> >> +
> >> +Required properties:
> >> + - compatible: shall be:
> >> +   - "renesas,cmm"
> >
> > There's a CMM in R-Car Gen2 with a different feature set, so I think you
> > need at least two compatible strings. As far as I can tell SoC-specific
> > compatible strings are required.
> 
> I assume you meant "SoC-specific compatible strings are NOT required" ?

Correct, sorry.

> Could you otherwise specify why do you think we need a per-SoC
> compatible, since there are no platform specific data (for now, at
> least, but considering the CMM seems identical in all SoCs I hardly
> think we will have any in the near future).
> 
> Ack on the gen2/gen3 specific strings though.
> 
> >> +
> >> + - reg: the address base and length of the memory area where CMM control
> >> +   registers are mapped to.
> >> +
> >> + - clocks: phandle and clock-specifier pair to the CMM functional clock
> >> +   supplier.
> >> +
> >> +Example:
> >> +--------
> >> +
> >> +	cmm0: cmm@fea40000 {
> >> +		compatible = "renesas,cmm";
> >> +		reg = <0 0xfea40000 0 0x1000>;
> >> +		power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
> >> +		clocks = <&cpg CPG_MOD 711>;
> >> +		resets = <&cpg 711>;
> >> +	};
Geert Uytterhoeven May 28, 2019, 2:50 p.m. UTC | #4
Hi Laurent,

On Tue, May 28, 2019 at 4:31 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Tue, May 28, 2019 at 02:37:25PM +0200, Jacopo Mondi wrote:
> > On Sat, May 11, 2019 at 09:16:18PM +0300, Laurent Pinchart wrote:
> > > On Wed, May 08, 2019 at 07:34:20PM +0200, Jacopo Mondi wrote:
> > >> Add device tree bindings documentation for the Renesas R-Car Display
> > >> Unit Color Management Module.
> > >>
> > >> CMM is the image enhancement module available on each R-Car DU video
> > >> channel.
> > >
> > > Not on all of them, V3M and V3H don't include a CMM module.
> > >
> > >> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

> > >> --- /dev/null
> > >> +++ b/Documentation/devicetree/bindings/display/renesas,cmm.txt
> > >> @@ -0,0 +1,24 @@
> > >> +* Renesas R-Car Color Management Unit (CMM)
> > >
> > > It's called Color Management Module in the documentation (hence the CMM
> > > abbreviation)
> > >
> > >> +
> > >> +Renesas R-Car image enhancement module connected to R-Car DU video channels.
> > >> +
> > >> +Required properties:
> > >> + - compatible: shall be:
> > >> +   - "renesas,cmm"
> > >
> > > There's a CMM in R-Car Gen2 with a different feature set, so I think you
> > > need at least two compatible strings. As far as I can tell SoC-specific
> > > compatible strings are required.
> >
> > I assume you meant "SoC-specific compatible strings are NOT required" ?
>
> Correct, sorry.
>
> > Could you otherwise specify why do you think we need a per-SoC
> > compatible, since there are no platform specific data (for now, at
> > least, but considering the CMM seems identical in all SoCs I hardly
> > think we will have any in the near future).
> >
> > Ack on the gen2/gen3 specific strings though.

Usually we do define SoC-specific compatible values in the DT bindings,
unless there is a version register, like on the VPSs.

Why would we want to deviate from that practice for the CMM?

Thanks!

Gr{oetje,eeting}s,

                        Geert

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/display/renesas,cmm.txt b/Documentation/devicetree/bindings/display/renesas,cmm.txt
new file mode 100644
index 000000000000..d7674417edb4
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/renesas,cmm.txt
@@ -0,0 +1,24 @@ 
+* Renesas R-Car Color Management Unit (CMM)
+
+Renesas R-Car image enhancement module connected to R-Car DU video channels.
+
+Required properties:
+ - compatible: shall be:
+   - "renesas,cmm"
+
+ - reg: the address base and length of the memory area where CMM control
+   registers are mapped to.
+
+ - clocks: phandle and clock-specifier pair to the CMM functional clock
+   supplier.
+
+Example:
+--------
+
+	cmm0: cmm@fea40000 {
+		compatible = "renesas,cmm";
+		reg = <0 0xfea40000 0 0x1000>;
+		power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
+		clocks = <&cpg CPG_MOD 711>;
+		resets = <&cpg 711>;
+	};