Hi,
On Fri, Nov 03, 2017 at 07:53:17AM +0800, Icenowy Zheng wrote:
> 在 2017-11-02 23:50，Maxime Ripard 写道：
> > On Thu, Nov 02, 2017 at 05:07:30PM +0800, Icenowy Zheng wrote:
> > > > > +&mmc0 {
> > > > > + pinctrl-names = "default";
> > > > > + pinctrl-0 = <&mmc0_pins_a>;
> > > > > + vmmc-supply = <®_vcc3v3>;
> > > > > + bus-width = <4>;
> > > > > + /*
> > > > > + * In different revisions the board have different card detect
> > > > > + * configuration.
> > > > > + */
> > > >
> > > > Which ones?
> > >
> > > In the sample batch (1.2V fixed voltage) the card detect is normal
> > > (PF6 low as inserted), however in the final batch (1.1V/1.3V
> > > switchable) it's inverted at PF6 (high as inserted).
> >
> > Then just use the final version's.
> >
> > > > > +&usbphy {
> > > > > + usb0_id_det-gpios = <&r_pio 0 6 GPIO_ACTIVE_HIGH>; /* PL6 */
> > > > > + /* USB OTG VBUS is directly connected to 5V without any regulators
> > > > > */
> > > >
> > > > So it cannot operate in OTG, but it's host only?
> > >
> > > It can operate in OTG -- you can power the board via the OTG port,
> > > as the VBUS is not gated from 5V at all, so 5V power at VBUS will
> > > power up the board. Yes, it's a bit unsafe, but the board designer
> > > did it.
> >
> > What will provide the 5v in the first place then if a USB device is
> > connected to the micro-USB connector?
>
> There're two micro-USB connectors, one is power-only and another is
> OTG. The Vbus of these two connectors are connected together, so
> the external USB device will be powered just by the power input
> from the power-only USB port.
Can you put that in the comment?
Thanks.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
Attachment:
signature.asc
Description: PGP signature
