ulpi_check_integrity returning error

[Fabio Estevam]

Hi Igor,

[Adding linux-arm-kernel]

On Tue, Dec 14, 2010 at 11:16 AM, Igor Grinberg <grinberg at compulab.co.il> wrote:
> Hi Fabio,
>
> On 12/14/10 00:14, Fabio Estevam wrote:
>> Hi,
>>
>> I am working on adding USB OTG host support for the mx31_3ds board
>> (OTG PHY is a ISP1504).
>
> ISP1504 seems like ULPI compliant transceiver.
>
>> USB OTG in device mode works fine and I can only get OTG host mode to
>> work if I force a 'return 0' into the ulpi_check_integrity function. I
>> was wondering if anyone has any suggestions as to where to
>> inspect/debug the fact that the read/write to the OTG PHY scratch
>> register does not match.
>
> Both ULPI specifications (1.0 and 1.1) define the Scratch register as:
> "an empty register byte for testing purposes. Software can read, write,
> set and clear this register; and the functionality of the PHY will not be affected."
> Therefore it should be implemented in the ISP1504 as such and according to
> NXP's ISP1504 datasheet it should be there...
>
> What about the ID? Do you get the vendor/product ID value as expected?

No, I am getting only zeros when reading vendor/product ID:

ULPI transceiver vendor/product ID 0x0000/0x0000

Even though the ULPI integrity check fails, if I force a 'return 0' in
this function, then I am able to mount a USB stick and it is
functional.

There are other i.MX boards that support OTG in host mode via ULPI,
such as pcm037, pca100, imx27_visstrim .

I am curious to know if any of this boards can work in host mode OTG
with current mainline kernel.

Thanks,

Fabio Estevam