[PATCH 10/11] usb: chipidea: imx: add binding for supporting runtime pm

[Marek Vasut]

Dear Peter Chen,

> On Sat, Oct 12, 2013 at 10:40:37AM -0400, Alan Stern wrote:
> > On Sat, 12 Oct 2013, Peter Chen wrote:
> > > Add property for supporting runtime power management
> > > 
> > > Signed-off-by: Peter Chen <peter.chen at freescale.com>
> > > ---
> > > 
> > >  .../devicetree/bindings/usb/ci13xxx-imx.txt        |    2 ++
> > >  1 files changed, 2 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> > > b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt index
> > > b4b5b79..f666598 100644
> > > --- a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> > > +++ b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
> > > 
> > > @@ -18,6 +18,7 @@ Optional properties:
> > >  - vbus-supply: regulator for vbus
> > >  - disable-over-current: disable over current detect
> > >  - external-vbus-divider: enables off-chip resistor divider for Vbus
> > > 
> > > +- supports_runtime_pm: enable runtime pm support
> > > 
> > >  Examples:
> > >  usb at 02184000 { /* USB OTG */
> > > 
> > > @@ -28,4 +29,5 @@ usb at 02184000 { /* USB OTG */
> > > 
> > >  	fsl,usbmisc = <&usbmisc 0>;
> > >  	disable-over-current;
> > >  	external-vbus-divider;
> > > 
> > > +	supports_runtime_pm;
> > > 
> > >  };
> > 
> > This does not sound like a property of the hardware.  What's the
> > _hardware_ difference between parts that support runtime PM and parts
> > that don't?
> 
> Thanks.
> 
> From my point, all hardware using chipidea core should support runtime pm.
> But some of platforms need special glue layer operations to support
> it, it will break other platforms if enable chipidea core runtime pm.
> Since device tree describes hardware property, maybe I should move
> it to glue layer, or do you have any suggestions?

You should certainly move it out of DT. This is linux-specific property, it has 
nothing to do with HW. The best course of action would be to fix those platforms 
that are broken by runtime PM.

Best regards,
Marek Vasut