Re: Chipidea ULPI driver

[Peter Chen <peter.chen@freescale.com>]

On Fri, Sep 11, 2015 at 11:34:10AM +0000, Subbaraya Sundeep Bhatta wrote:
> Hi,
> 
> > -----Original Message-----
> > From: Peter Chen [mailto:peter.chen@freescale.com]
> > Sent: Friday, September 11, 2015 6:52 AM
> > To: Punnaiah Choudary Kalluri
> > Cc: balbi@ti.com; Subbaraya Sundeep Bhatta; linux-usb@vger.kernel.org; linux-
> > kernel@vger.kernel.org; Greg Kroah-Hartman (gregkh@linuxfoundation.org);
> > kishon@ti.com
> > Subject: Re: Chipidea ULPI driver
> > 
> > On Thu, Sep 10, 2015 at 02:57:49PM +0000, Punnaiah Choudary Kalluri wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Felipe Balbi [mailto:balbi@ti.com]
> > > > Sent: Thursday, September 10, 2015 8:14 PM
> > > > To: Subbaraya Sundeep Bhatta
> > > > Cc: Peter Chen; balbi@ti.com; linux-usb@vger.kernel.org; linux-
> > > > kernel@vger.kernel.org; Greg Kroah-Hartman
> > > > (gregkh@linuxfoundation.org); kishon@ti.com; Punnaiah Choudary
> > > > Kalluri
> > > > Subject: Re: Chipidea ULPI driver
> > > >
> > > > (break your lines at 80-characters)
> > > >
> > > > On Thu, Sep 10, 2015 at 12:44:58PM +0000, Subbaraya Sundeep Bhatta
> > wrote:
> > > > > Hi Peter,
> > > > >
> > > > > We are using NOP transceiver driver for USB3320 ULPI PHY with
> > > > > ChipIdea controller.
> > > > >
> > > > > Recently we found that one of the boards (zedboard) requires PHY
> > > > > register access to set VBUS.
> > > > >
> > > > > Note that our local driver we had before migrating to ChipIdea
> > > > > driver calls otg_ulpi_create with flags  ULPI_OTG_DRVVBUS |
> > > > > ULPI_OTG_DRVVBUS_EXT so that VBUS is enabled at initialization.
> > > > >
> > > > > Can you please let me know how to do this with ChipIdea case? I
> > > > > see the following solutions:
> > > > >
> > > > > 1. Write ULPI driver for USB3320 similar to tusb1210.
> > > >
> > > > this
> > >
> > > How about extending the phy-ulpi driver to use it as platform driver?
> > > So that boards that are using the ulpi compatible phy and driving vbus
> > > from the phy can use this driver.
> > >
> > 
> > Yes, you can improve phy-ulpi driver, and it can not depend on NOP transceiver
> > driver.
> 
> AFAIK phy-ulpi.c is just exporting functions and not registering to platform
> bus since it is not connected to SOC bus. I don't think we can create platform
> driver for this. I have read TUSB1210 data sheet and it is similar to USB3320
> with no additional SOC bus connection and has only ULPI interface. 
> So it should register to ULPI bus which is in kernel recently. I will make
> changes to chipidea similar to dwc3(adding ulpi.c) and write driver similar
> to tusb1210.c. Is that okay?
> 

It should be ok.

-- 

Best Regards,
Peter Chen