On Mon, Jul 18, 2016 at 08:24:50AM -0700, Joshua Clayton wrote: > Greetings, > On 07/18/2016 04:15 AM, Li Jun wrote: > > Adding over-current-polarity to indicate the over current flag > > is low active or high active. > > > > Signed-off-by: Li Jun <jun.li@xxxxxxx> > > --- > > Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > index 341dc67..c5d35f4 100644 > > --- a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > +++ b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > @@ -81,6 +81,8 @@ i.mx specific properties > > - fsl,usbmisc: phandler of non-core register device, with one > > argument that indicate usb controller index > > - disable-over-current: disable over current detect > > +- over-current-polarity: 0 if the over current signal polarity is low active, > > + 1 if the over current signal polarity is high active. > > - external-vbus-divider: enables off-chip resistor divider for Vbus > > > > Example: > The gpio device bindings already have active low/ active high. > Could that be used here? > No, the over current pin is a dedicated pin for USB, you need to configure it through pinmux. If we are using a gpio (even the same pin as OC pin), the USB subsystem will not know OC event. The polarity is for OC pin and configured through USB register. > In the imx SPI subsystem, for instance, the developers used gpio rather than > MUXED spi chipselect lines for exactly this kind of flexibility. > > If there is no magic happening in silicon (which would seem to be the case if we can > handle inverting polarity in the driver), I would suggest going the gpiod route. > -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
