Re: [PATCH v1 1/2] remoteproc: dt: Provide bindings for iMX6SX/7D Remote Processor Controller driver

[Oleksij Rempel]

Hallo Bjorn,

On 11.07.2017 00:14, Bjorn Andersson wrote:
> On Mon 10 Jul 07:42 PDT 2017, Oleksij Rempel wrote:
>
> > Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/remoteproc/imx-rproc.txt   | 44 ++++++++++++++++++++++
> >  1 file changed, 44 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/remoteproc/imx-rproc.txt
> >
> > diff --git a/Documentation/devicetree/bindings/remoteproc/imx-rproc.txt b/Documentation/devicetree/bindings/remoteproc/imx-rproc.txt
> > new file mode 100644
> > index 000000000000..e7c61993e1b8
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/remoteproc/imx-rproc.txt
> > @@ -0,0 +1,44 @@
> > +NXP iMX6SX/iMX7D Co-Processor Bindings
> > +----------------------------------------
> > +
> > +This binding provides support for ARM Cortex M4 Co-processor found on some
> > +NXP iMX SoCs.
> > +
> > +Required properties:
> > +- compatible		Should be one of:
> > +				"fsl,imx7d-rproc"
> > +				"fsl,imx6sx-rproc"
> > +- clocks		Clock for co-processor (See: ../clock/clock-bindings.txt)
> > +- syscfg		Phandle to syscon block which provide access to
>
> This is called "syscon" in the code and the example.

done.

> > +			System Reset Controller
> > +
> > +Optional properties:
> > +- reg:			Should contain the address ranges for some of internal
> > +			memory regions.
>
> Something less hand-wavy, like: "Should list the memory regions for the
> remoteproc"
>
> > +- reg-names:		Contains the corresponding names for the memory
> > +			regions. These should be named "ddr", "ocram", "ocram-s",
> > +			"ocram-epdc" or "ocram-pxp".
>
> Make this comment define which memory regions are required for each of
> the systems.

done.

> > +Fallowing memory ranges are expected:
> > +- For "fsl,imx7d-rproc"
> > +	<0x00900000 0x00020000> - "ocram"
> > +	<0x00920000 0x00020000> - "ocram-epdc"
> > +	<0x00940000 0x00008000> - "ocram-pxp"
> > +	<0x80000000 0x0FFF0000> - "ddr" (code area)
> > +	<0x80000000 0x60000000> - "ddr" (data area)
>
> There's no reason to list the actual regions in the binding
> document. Just list the requires regions for each system.
>
> > +- For "fsl,imx6sx-rproc"
> > +	<0x008F8000 0x00004000> - "ocram-s"
> > +	<0x80000000 0x0FFF8000> - "ddr" (code area)
> > +	<0x80000000 0x60000000> - "ddr" (data area)
> > +
> > +Note: the "ddr" code and data ranges are overlapping. Code area is smaller
> > +than data area.  So this range should be carefully chosen according to your
> > +system and application requirements.
> > +
>
> This is a source of future issues as this indicates that I should have
> reg-names list "ddr" twice.

Then I will name it:
"ddri" (incstruction/code area),
"ddrd" (data area)

unless there are other suggestions.

> Also, as you warn about the user needing to pick the values for "ddr",
> does that mean that it's a carveout of System RAM?

Yes, it is a part of System RAM.

> > +Example:
> > +	imx_rproc: imx7d-rp0@0 {
>
> imx7d-rproc@80000000 {
>
> And there's currently no reason to label this node.
>
> > +		compatible	= "fsl,imx7d-rproc";
> > +		reg		= <0x80000000 0x80000>, <0x00900000 0x2000>;
> > +		reg-names	= "ddr", "ocram";
> > +		syscon		= <&src>;
> > +		clocks		= <&clks IMX7D_ARM_M4_ROOT_CLK>;
> > +	};

Regards,
Oleksij