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

Yang, Wenyou
2016-06-03T09:22:42Z

> -----Original Message-----
> From: Rob Herring [mailto:robh at kernel.org]
> Sent: 2016?6?3? 9:54
> To: Yang, Wenyou <Wenyou.Yang@atmel.com>
> Cc: Alan Stern <stern@rowland.harvard.edu>; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Ferre, Nicolas <Nicolas.FERRE@atmel.com>;
> Pawel Moll <pawel.moll@arm.com>; Mark Brown <broonie@kernel.org>; Ian
> Campbell <ijc+devicetree@hellion.org.uk>; Kumar Gala <galak@codeaurora.org>;
> Alexandre Belloni <alexandre.belloni@free-electrons.com>; linux-
> kernel at vger.kernel.org; devicetree at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; linux-usb at vger.kernel.org
> 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@atmel.com>
> > ---
> >
> > 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