[U-Boot] [PATCH 4/4] README: add documentation for CONFIG_USB_ULPI*

[Remy Bohmer]

Hi Igor,

2011/12/15 Igor Grinberg <grinberg at compulab.co.il>:
>>>> Where does it say that only this one is supported in the code?
>>>
>>> You mean comments or the code?
>>
>> Well the filename seems generic and not specific to that chip. Are
>> viewports something that other chips can support?
>
> Let me clarify:
> 1) It is not the chip it is the controller (IP block) inside the SoC.
> 2) viewport is just the register name inside the SoC that provides
>   and interface of the controller to access the ULPI PHY.
>
> I think every SoC that uses that controller has the viewport setup
> this way, but I might be wrong (and that's why the viewport is
> separated from the generic ULPI spec implementation).
>
> Regarding the name... yeah it could be renamed, but it follows Linux
> naming currently and it is the first one submitted,
> so IMO it can be named that generically.
>
>>
>> COBJS-$(CONFIG_USB_ULPI)              += ulpi.o
>> COBJS-$(CONFIG_USB_ULPI_VIEWPORT)     += ulpi-viewport.o
>>
>> It would be good if you could mention the two new CONFIG options in the README.
>
> I did, see below...
>
>>
>>>
>>>> What is specific to that device?
>>>
>>> The viewport bits? It is not a part of the ULPI spec.
>>> Other vendors do not have to comply with those.
>>> For example PXA310 has those bits placed and named in some other way...
>>
>> OK I didn't realise that.
>
> I think same stand for OMAP, but I'm not sure.
> OMAP still does arbitrary register writes for accessing ULPI.
>
>>
>>>>> +               To enable the ULPI layer support, define CONFIG_USB_ULPI and
>>>>> +               CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
>
> Here the configs are documented.
> I admit, it is not that brilliant documentation...

Are you planning to post an update of this patch? The rest of the
series I already pulled into the USB tree.

Kind regards,

Remy