RE: [PATCH v2 1/2] usb: ohci-at91: Forcibly suspend ports while USB suspend

[Yang, Wenyou]

> -----Original Message-----
> From: Rob Herring [mailto:robh@xxxxxxxxxx]
> Sent: 2016年6月3日 9:54
> To: Yang, Wenyou <Wenyou.Yang@xxxxxxxxx>
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Ferre, Nicolas <Nicolas.FERRE@xxxxxxxxx>;
> Pawel Moll <pawel.moll@xxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; Ian
> Campbell <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar Gala <galak@xxxxxxxxxxxxxx>;
> Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 1/2] usb: ohci-at91: Forcibly suspend ports while USB
> suspend
> 
> On Wed, Jun 01, 2016 at 12:29:59PM +0800, Wenyou Yang wrote:
> > In order to the save power consumption, as a workaround, suspend
> > forcibly the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI
> > Interrupt Configuration Register in the SFRs while OHCI USB suspend.
> >
> > This suspend operation must be done before the USB clock is disabled,
> > resume after the USB clock is enabled.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> > ---
> >
> > Changes in v2:
> >  - Add compatible to support forcibly suspend the ports.
> >  - Add soc/at91/at91_sfr.h to accommodate the defines.
> >  - Add error checking for .sfr_regmap.
> >  - Remove unnecessary regmap_read() statement.
> >
> >  .../devicetree/bindings/usb/atmel-usb.txt          |  5 +-
> >  drivers/usb/host/ohci-at91.c                       | 80 +++++++++++++++++++++-
> >  include/soc/at91/at91_sfr.h                        | 29 ++++++++
> >  3 files changed, 111 insertions(+), 3 deletions(-)  create mode
> > 100644 include/soc/at91/at91_sfr.h
> >
> > diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt
> > b/Documentation/devicetree/bindings/usb/atmel-usb.txt
> > index 5883b73..3e3e58a 100644
> > --- a/Documentation/devicetree/bindings/usb/atmel-usb.txt
> > +++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt
> > @@ -3,8 +3,9 @@ Atmel SOC USB controllers  OHCI
> >
> >  Required properties:
> > - - compatible: Should be "atmel,at91rm9200-ohci" for USB controllers
> > -   used in host mode.
> > + - compatible: Should be one of the following
> > +	       "atmel,at91rm9200-ohci" for USB controllers used in host mode.
> > +	       "atmel,sama5d2-ohci" for SAMA5D2 which can force to suspend.
> 
> That may be why you need this now, but that is irrelevant to having a chip specific
> compatible string.

Maybe a property is better.


Best Regards,
Wenyou Yang