[PATCH 2/4] usb: dwc3: Fix gadget pullup in SS mode

[Sonasath, Moiz]

Felipe,

On Wed, Sep 19, 2012 at 11:04 AM, Felipe Balbi <balbi at ti.com> wrote:

> Hi,
>
> On Wed, Sep 19, 2012 at 10:02:48AM -0500, Sonasath, Moiz wrote:
> > Felipe,
> >
> > On Wed, Sep 19, 2012 at 6:53 AM, Felipe Balbi <balbi at ti.com> wrote:
> >
> > > Hi,
> > >
> > > On Wed, Sep 19, 2012 at 05:00:27PM +0530, Kishon Vijay Abraham I wrote:
> > > > From: Moiz Sonasath <m-sonasath at ti.com>
> > > >
> > > > For the gadget pullup functionality to work in
> > > > SS mode it requires a particular sequence of
> > > > toggling the run-stop bit. Here is the required
> > > > sequence:
> > > >
> > > > - Set DCTL[31]
> > > > - Clear DCTL[31]
> > > > - Clear OMAP5430_CONTROL_CORE__PHY_POWER_USB[14]
> > > > - Clear DCTL[8:5] = 0x00
> > > > - Set DCTL[8:5] = 0x05
> > > > - Wait 25 Ms
> > > > - Set DCTL[31]
> > > > - Set OMAP5430_CONTROL_CORE__PHY_POWER_USB[14]
> > > >
> > > > Tested rigourously the gadget pull-up functionality
> > > > in bot HS and SS modes.
> > > >
> > > > Signed-off-by: Moiz Sonasath <m-sonasath at ti.com>
> > > > Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
> > >
> > > this needs to split into three patches:
> > >
> > > add new poweron field, implement it on omap-usb3, use it on
> > > dwc3/gadget.c
> > >
> > > btw, I don't think the changes to run_stop bit are necessary and if
> they
> > > are, that'd either be a silicon errata or it would've been mentioned on
> > > the databook. I don't remember seeing that on the databook so I'm
> > > assuming that this is caused by a bad use of the PHY.
> > >
> > > Why that mdelay(25) ? why 25 ms ? That's quite a long time, actually.
> > >
> >
> > Felipe, This is infact a HW bug that the Si-Val team did accept and gave
> us
> > this workaround sequence with the precise delay :-)
> >
> > Supposedly this will be fixed in ES 2.0.
>
> in that case this doesn't have to go to mainline since we're not
> supporting ES1.0 in mainline :-)
>
> at minimum this should've come with a proper revision check anyway.
>

Actually most of it is under a rev check :)

Perhaps the last: usb_phy_shutdown(dwc->usb3_phy);
in the else part should be in
if (dwc->revision <= DWC3_REVISION_187A) check

Kishon, can you resend please?

>
> --
> balbi
>



-- 
Regards
Moiz Sonasath
Android Kernel Team
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