Hi Javier,
On 04/11/2013 01:58 AM, Javier Martinez Canillas wrote:
> On Wed, Apr 10, 2013 at 7:31 PM, Jon Hunter <jon-hunter@xxxxxx> wrote:
>> Hi Tony,
>>
>> On 04/09/2013 04:23 PM, Tony Lindgren wrote:
>>> Hi Jon,
>>>
>>> Looks like at least 4430sdp nfsroot got broken with commit
>>> ff5c9059 (ARM: dts: OMAP3+: Correct gpio #interrupts-cells
>>> property).
>>
>> Thanks for reporting. I am actually amazed that ethernet is
>> working on any OMAP board (with device-tree) that requires a
>> gpio as an interrupt because we have still not come to an
>> agreement on [1]. Looking at the OMAP4 SDP I believe this is
>> working by luck because there are other gpios in the same
>> bank that are active and so the bank is enabled. If that were
>> not the case then this would not work.
>>
>
> Hi Jon,
>
> Ethernet is working on 4430sdp since the optional "gpio" property is
> specified on the fixed regulator used by the eth device node.
>
> From arch/arm/boot/dts/omap4-sdp.dts:
>
> vdd_eth: fixedregulator-vdd-eth {
> compatible = "regulator-fixed";
> regulator-name = "VDD_ETH";
> regulator-min-microvolt = <3300000>;
> regulator-max-microvolt = <3300000>;
> gpio = <&gpio2 16 0>; /* gpio line 48 */
> enable-active-high;
> regulator-boot-on;
> };
> ...
> &mcspi1 {
> eth@0 {
> compatible = "ks8851";
> spi-max-frequency = <24000000>;
> reg = <0>;
> interrupt-parent = <&gpio2>;
> interrupts = <2>; /* gpio line 34 */
> vdd-supply = <&vdd_eth>;
> };
> };
>
> So is the regulator who is calling gpio_request() and enabling the
> GPIO bank and no the ks881 ethernet driver. That's why it was working
> although I think is just a DT hack and should be changed once we found
> a proper solution to fhis.
It is not really a hack. There is a regulator controlled by a GPIO that
can control the Ethernet chip power. Both gpio48 and gpio34 are used for
Ethernet. On some SDP version there is even a third line, but I was not
able to find any evidence in the schematic I was using.
Regards,
Benoit
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