Re: [PATCH v5 6/6] usb: musb: dsps: Enable sw babble control for newer silicon

[George Cherian]

On 5/22/2014 5:28 PM, Sergei Shtylyov wrote:
> Hello.
>
> On 22-05-2014 10:29, George Cherian wrote:
>
> > Find whether we are running on newer silicon. The babble control
> > register reads 0x4 by default in newer silicon as opposed to 0
> > in old versions of AM335x. Based on this enable the sw babble
> > control logic.
>
> > Signed-off-by: George Cherian <george.cherian@xxxxxx>
> > ---
> >   drivers/usb/musb/musb_dsps.c | 38 
> > ++++++++++++++++++++++++++++++++------
> >   1 file changed, 32 insertions(+), 6 deletions(-)
>
> > diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
> > index 868caf8..2ced061 100644
> > --- a/drivers/usb/musb/musb_dsps.c
> > +++ b/drivers/usb/musb/musb_dsps.c
> [...]
> > @@ -469,6 +470,19 @@ static int dsps_musb_init(struct musb *musb)
> >       val &= ~(1 << wrp->otg_disable);
> >       dsps_writel(musb->ctrl_base, wrp->phy_utmi, val);
> >
> > +    /*
> > +     *  Check whether the dsps version has babble control enabled.
>
>    One space too many before this sentence.
>
> > +     * In latest silicon revision the babble control logic is enabled.
> > +     * If MUSB_BABBLE_CTL returns 0x4 then we have the babble control
> > +     * logic enabled.
> > +     */
> > +    val = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
> > +    if (val == MUSB_BABBLE_RCV_DISABLE) {
> > +        glue->sw_babble_enabled = true;
> > +        val |= MUSB_BABBLE_SW_SESSION_CTRL;
> > +        dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, val);
> > +    }
> > +
>
>    Hm, from the register offset that you declared in the previous 
> patch, I got an impression that this is a new standard MUSB register? 
Its very AM335x MUSB specific register, not a standard one.
Unfortunately the designers put it as part of MUSB core regs.
> Shouldn't this check be done in the generic MUSB code then?
>
> WBR, Sergei


--
-George

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