Re: [PATCH] usb: musb: dsps: implement vbus_status method

[Roman Alyautdin]

On 08/10/15 17:07, Sergei Shtylyov wrote:
> On 10/8/2015 4:50 PM, Sergei Shtylyov wrote:
>
> > > Implement vbus_status  method of musb_platform_ops that allows
> > > musb_core to properly represent the VBUS status of musb_dsps devices in
> > > corresponding sysfs entry
> > >
> > > Signed-off-by: Roman Alyautdin <ralyautdin@xxxxxxxxxxxxx>
> > > ---
> > >   drivers/usb/musb/musb_dsps.c |   13 +++++++++++++
> > >   1 file changed, 13 insertions(+)
> > >
> > > diff --git a/drivers/usb/musb/musb_dsps.c 
> > > b/drivers/usb/musb/musb_dsps.c
> > > index 84512d1..9c00edf 100644
> > > --- a/drivers/usb/musb/musb_dsps.c
> > > +++ b/drivers/usb/musb/musb_dsps.c
> > > @@ -632,6 +632,18 @@ static void dsps_read_fifo32(struct musb_hw_ep 
> > > *hw_ep,
> > > u16 len, u8 *dst)
> > >       }
> > >   }
> > >
> > > +static int dsps_musb_vbus_status(struct musb *musb)
> > > +{
> > > +    void __iomem *mregs = musb->mregs;
> > > +    u8 devctl;
> > > +
> > > +    devctl = dsps_readb(mregs, MUSB_DEVCTL);
> > > +    if ((devctl & MUSB_DEVCTL_VBUS) == (3 << MUSB_DEVCTL_VBUS_SHIFT))
> >
> >     I don't see why this has to be is implemented in the DSPS glue 
> > layer. The
> > DevCtl register is a standard MUSB one.
>
>    Looking at the musb_platform_get_vbus_status(), it's unclear why it 
> returns 0 if the vbus_status() method id undefined. I think we should 
> read the DevCtl registre here, removing the FIXME at the call site.

Maybe it is worth to return -EINVAL from musb_platform_get_vbus_status 
in case of method is undefined and keep current logic of interface 
implementation in platform-specific driver.

Hence print "Vbus unknown" in musb_vbus_show() in case of -EINVAL from 
musb_platform_get_vbus_status

Regards,
Roman


> MBR, Sergei

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