On Thu, Mar 14, 2013 at 09:53:55AM +0100, Marc Kleine-Budde wrote:
> On 03/14/2013 09:34 AM, Peter Chen wrote:
> > Hi Alex and all,
> >
> > Currently, we have two problems to block chipidea driver coming
> > development.
> >
> > As there are so many chipidea versions, we impossible to collect
> > all to make a decision, it is better to cover most of the cases,
> > and using device tree (or platform data) to cover exceptions
> > if they exist.
> >
> > 1. USB Mode Problem
> > How can we decide USB mode (gadget, host and otg) at driver, and
> > how to read OTGSC register? Below is my pinion.
> >
> > - We get gadget or host support from CAP_DCCPARAMS(DCCPARAMS_DC or
> > DCCPARAMS_HC),
>
> IIRC This is broken on mx25. The host only port gets into an error state
> if you read this register. :(
If there is an exception, you can use DT to override it. Eg:
if (ci->dccparams_is_error)
do not read DCCPARAMS; /* using DT dr_mode setting */
>
> There is a core on mips which doesn't support otg. From my point of
> view, support for dual_role should be a separate patch, ideally by
> Svetoslav (Cc'ed) who has this hardware, after we've cleaned up all
> dr-mode related stuff.
What means support OTG? The spec said it or there is a port
DCCPARAMS_DC =1 but DCCPARAMS_HC = 0?
>From my point, I still think if DCCPARAMS_DC = 1, it is save to
read OTGSC.
--
Best Regards,
Peter Chen
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