Hi Chris,
On Wed, May 15, 2019 at 4:03 PM Chris Brandt <Chris.Brandt@xxxxxxxxxxx> wrote:
> On Wed, May 15, 2019, Geert Uytterhoeven wrote:
> > > +/* USB-0 as Host */
> > > +/* NOTE: Requires JP3 to be fitted */
> >
> > This not applies to the dr_mode property below, right?
> > So perhaps it should be moved there...
> >
> > > +&usb2_phy0 {
> > > + pinctrl-names = "default";
> > > + pinctrl-0 = <&usb0_pins>;
> > > + dr_mode = "host";
> >
> > ... like:
> >
> > dr_mode = "host"; /* Requires JP3 to be fitted */
>
> OK, if you think it makes more sense there.
>
> > Does resistor R78 need to be mounted, too?
>
> By default, R78 and R79 are not populated on these boards, and both Host
> and Function work fine without board modification, so I would say
> populating R78 is not a requirement as far as I can tell.
I asked because after reading Section 2.4 USB Interface in the RZ/A2M CPU
Board User's Manual, it's not clear to me when one needs to
populate one of these resistors. Especially in relation to JP3, which
talks about 2 possible modes (host vs. function), while the resistor
paragraph talks about 3 possible modes (dual-role vs. host vs.
function).
Perhaps I just need to drink more USB Kool-Aid?
(no Kool-Aid sold in local shops, though; we live on Coke ;-)
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
