On Thu, 2013-08-08 at 14:14 -0600, Stephen Warren wrote:
> On 08/05/2013 02:43 PM, dinguyen@xxxxxxxxxx wrote:
> > From: Dinh Nguyen <dinguyen@xxxxxxxxxx>
> >
> > Add bindings for SD/MMC for SOCFPGA.
> > Add "syscon" to the "altr,sys-mgr" binding.
>
> > diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> > new file mode 100644
> > index 0000000..dc14922
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> > @@ -0,0 +1,48 @@
> > +* Altera SOCFPGA specific extensions to the Synopsis Designware Mobile
> > + Storage Host Controller
> > +
> > +Required Properties:
> > +
> > +* compatible: should be
> > + - "altr,socfpga-dw-mshc": for controllers with Altera SOCFPGA
> > + specific extensions.
> > +
> > +* altr,dw-mshc-ciu-div: Specifies the divider value for the card interface
> > + unit (ciu) clock. The value should be (n-1). For Altera's SOCFPGA, the divider
> > + value is fixed at 3, which means parent_clock/4.
>
> This feels like something that should be represented using the common
> clock API; a driver should query the rate of its input clock, and then
> calculate the MMC block's internal divider based on that (perhaps also
> call clk_set_rate() on the input clock?).
This means a change to the dw_mmc driver, which I can look into for the
next round? I have promised Pawel to consolidate the bindings for both
exynos and socfpga in the next round already. I will also look into
using the common clock API for the MMC as well.
This patch is the only thing that is preventing from SD/MMC working for
SOCFPGA in the mainline, can I get your Ack if I look into doing this
for 3.13 for both the exynos and socfpga driver, and address your latter
comments?
>
> > +Example:
> > + dwmmc0@ff704000 {
> > + compatible = "altr,socfpga-dw-mshc", "snps,dw-mshc";
> > + reg = <0xff704000 0x1000>;
> > + interrupts = <0 139 4>;
>
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + num-slots = <1>;
> > + supports-highspeed;
> > + fifo-depth = <0x400>;
>
> Those properties aren't defined in this document anywhere. I guess this
> binding is meant to "inherit" from that described in
> "synopsis-dw-mshc.txt"? If so, that should be stated explicitly.
Yes, will state in v3.
>
> A similar comment applies to the clocks properties in the *.dtsi changes.
>
> > + altr,dw-mshc-ciu-div = <3>;
> > + altr,dw-mshc-sdr-timing = <0 3>;
>
> Indentation issue.
Will fix..
Dinh
>
>
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