OTG implementation with external transceiver on PXA270

[Eric Miao]

On Mon, May 10, 2010 at 9:33 AM, Sergey Lapin <slapinid at gmail.com> wrote:
> Hi, all!
>
> I try to implement external OTG transceiver on PXA270.
> I just need basic device mode at the moment.
>
> A problem is that PXA itself handles interrupt of external chip via
> UDC interrupt. But I need to read my chip-specific registers
> from there while I want to maintain pxa270_udc in a generic way
> without cluttering it with i2c calls, so I can implement it in the
> following ways:
>
> * make chip-specific data struct global (like it is in isp1301_omap.c
> and make exported function in OTG driver, enable handling of OTG interrupts
> in pxa27x_udc and call that function from there.
> * add API function like otg_handle_interrupt, enable handling of OTG interrupts
> in pxa27x_udc and call it from there. Which seems to be less messy.
>
> Any other suggestions? If that work is really being done somewhere,
> I'd like to help with testing.
>

The problem with isp1301_omap.c is that it's not separating the components
into otg controller and otg transciever, which means at the moment the quickest
way is to write something similar as isp1301_pxa27x.c, but apparently, the
optimal way in my POV is to have a good abstraction, so the OTG transceiver
and controller code can be re-used.