[PATCHv2] ARM: socfpga: dts: Add support for SD/MMC
Stephen Warren
swarren at wwwdotorg.org
Thu Aug 8 16:14:18 EDT 2013
On 08/05/2013 02:43 PM, dinguyen at altera.com wrote:
> From: Dinh Nguyen <dinguyen at altera.com>
>
> 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?).
> +Example:
> + dwmmc0 at 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.
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.
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