[PATCHv2 1/2] ARM: dts: socfpga: Fix SD card detect

[Doug Anderson]

Dinh,

On Mon, Oct 20, 2014 at 12:30 PM, Doug Anderson <dianders at chromium.org> wrote:
> Dinh,
>
> On Mon, Oct 20, 2014 at 9:31 AM, Dinh Nguyen
> <dinguyen at opensource.altera.com> wrote:
>>>>  &mmc0 {
>>>> -       cd-gpios = <&gpio1 18 0>;
>>>> +       cd = <&gpio1 18 0>;
>>>
>>> This doesn't look right to me.  What was the error that was passed back?
>>>
>>> I think your change has the same net effect as just deleting the
>>> "cd-gpios" line.  ...or is there some code somewhere that is parsing
>>> the "cd" property.
>>>
>>
>> It just hangs here:
>>
>> dw_mmc ff704000.dwmmc0: Using PIO mode.
>> dw_mmc ff704000.dwmmc0: Version ID is 240a
>> dw_mmc ff704000.dwmmc0: DW MMC controller at irq 171, 32 bit host data
>> width, 1024 deep fifo
>> platform ff704000.dwmmc0: Driver dw_mmc requests probe deferral
>>
>>
>> Without this patch :
>> mmc_of_parse ret=-517 (EPROBE_DEFER)
>
> I think you need to dig more into this error.  Why are you getting an
> -EPROBE_DEFER when you asked for this GPIO?
>
> The -EPROBE_DEFER tells the system that a resource is not available
> yet and that it should try to re-run the dw_mmc init later once the
> resource becomes available.  I believe that some other bug is causing
> the resource to never become available.
>
> Guesses:
>
> * The GPIO specifier is wrong in the DTB and is pointing to a GPIO
> that would never exist.
>
> * Something is happening in the GPIO driver that is causing it to fail.
>
>
> ...so we need to dig in further.

One odd thing is that it looks like the GPIO controller you're
referencing is disabled.  On today's linuxnext, you can see the
"disabled":

arch/arm/boot/dts/socfpga.dtsi:         gpio at ff709000 {
arch/arm/boot/dts/socfpga.dtsi-                 #address-cells = <1>;
arch/arm/boot/dts/socfpga.dtsi-                 #size-cells = <0>;
arch/arm/boot/dts/socfpga.dtsi-                 compatible = "snps,dw-apb-gpio";
arch/arm/boot/dts/socfpga.dtsi-                 reg = <0xff709000 0x1000>;
arch/arm/boot/dts/socfpga.dtsi-                 clocks = <&per_base_clk>;
arch/arm/boot/dts/socfpga.dtsi-                 status = "disabled";
arch/arm/boot/dts/socfpga.dtsi-
arch/arm/boot/dts/socfpga.dtsi-                 gpio1: gpio-controller at 0 {
arch/arm/boot/dts/socfpga.dtsi-                         compatible =
"snps,dw-apb-gpio-port";
arch/arm/boot/dts/socfpga.dtsi-                         gpio-controller;

I don't see anyone else referencing that node to enable it.  ...to me
that means that you can't use GPIOs on GPIO1 (???).


...or did I find something wrong?


-Doug