RE: [PATCH v3 4/4] doc: usb: ci-hdrc-usb2: Add pinctrl properties for HSIC pin groups

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> 
> On Tue, Nov 27, 2018 at 7:31 AM PETER CHEN <peter.chen@xxxxxxx> wrote:
> >
> > For USB HSIC, the data and strobe pin needs to be pulled down at
> > default, we consider it as "idle" state. When the USB host is ready to
> > be used, the strobe pin needs to be pulled up, we consider it as
> > "active" state.
> >
> > Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
> > ---
> >  Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
> > b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
> > index 529e51879fb2..1e5e7ddfb1a5 100644
> > --- a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
> > +++ b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
> > @@ -80,7 +80,10 @@ Optional properties:
> >    controller. It's expected that a mux state of 0 indicates device mode and a
> >    mux state of 1 indicates host mode.
> >  - mux-control-names: Shall be "usb_switch" if mux-controls is specified.
> > -- pinctrl-names: Names for optional pin modes in "default", "host", "device"
> > +- pinctrl-names: Names for optional pin modes in "default", "host", "device".
> > +  In case of HSIC-mode, "idle" and "active" pin modes are mandatory.
> > +In this
> > +  case, the "idle" state needs to pull down the data and strobe pin
> > +  and the "active" state needs to pull up the strobe pin.
> >  - pinctrl-n: alternate pin modes
> >
> >  i.mx specific properties
> > @@ -110,4 +113,7 @@ Example:
> >                 phy-clkgate-delay-us = <400>;
> >                 mux-controls = <&usb_switch>;
> >                 mux-control-names = "usb_switch";
> > +               pinctrl-names = "idle", "active";
> > +               pinctrl-0 = <&pinctrl_usbh2_1>;
> > +               pinctrl-1 = <&pinctrl_usbh2_2>;
> 
> I would put the "idle" and "active" entries inside a explicit section for HSIC.
> 
> Otherwise, it may confuse people using non-HSIC bindings.

It is just an example; the user should check the meaning for optional properties before
using it, like the property "phy-clkgate-delay-us", only imx7d/7s needs it.

Peter




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