Re: [PATCH v12 5/6] ARM: socfpga: add bindings document for fpga bridge drivers

From: atull
Date: Wed Oct 28 2015 - 12:00:32 EST


On Wed, 28 Oct 2015, Steffen Trumtrar wrote:

> Hi!
>
> On Tue, Oct 27, 2015 at 05:09:14PM -0500, atull@xxxxxxxxxxxxxxxxxxxxx wrote:
> > From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
> >
> > Add bindings documentation for Altera SOCFPGA bridges:
> > * fpga2sdram
> > * fpga2hps
> > * hps2fpga
> > * lwhps2fpga
> >
> > Signed-off-by: Alan Tull <dinguyen@xxxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Matthew Gerlach <mgerlach@xxxxxxxxxx>
> > ---
> > v2: separate into 2 documents for the 2 drivers
> > v12: bump version to line up with simple-fpga-bus version
> > remove Linux specific notes such as references to sysfs
> > move non-DT specific documentation elsewhere
> > remove bindings that would have been used to pass configuration
> > clean up formatting
> > ---
> > .../bindings/fpga/altera-fpga2sdram-bridge.txt | 18 ++++++++++
> > .../bindings/fpga/altera-hps2fpga-bridge.txt | 36 ++++++++++++++++++++
> > 2 files changed, 54 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt
> > create mode 100644 Documentation/devicetree/bindings/fpga/altera-hps2fpga-bridge.txt
> >
> > diff --git a/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt b/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt
> > new file mode 100644
> > index 0000000..11eb5b7
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt
> > @@ -0,0 +1,18 @@
> > +Altera FPGA To SDRAM Bridge Driver
> > +
> > +Required properties:
> > +- compatible : Should contain "altr,socfpga-fpga2sdram-bridge"
> > +
> > +Optional properties:
> > +- label : User-readable name for this bridge.
> > + Default is br<device#>
> > +- init-val : 0 if driver should disable bridge at startup
> > + 1 if driver should enable bridge at startup
> > + Default is to leave bridge in current state.
>
> I know, that there are bindings, that configure via devicetree, but AFAIK
> this is not okay.

Yes there is configuration in the DT. I attended a presentation at ELC in
Dublin 3 weeks ago - Frank Rowand on "Solving Device Tree Issues." He said in
addition to non-probable hardware information, it was a "dirty secret" that DT
includes configuration information and some policy.

Alan
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