[PATCH] arm: dtsi: am335x-bone-common, usb0 is peripheral only

[Markus Pargmann]

Hi,

On Thu, Feb 13, 2014 at 02:54:38PM -0800, Tony Lindgren wrote:
> * Markus Pargmann <mpa at pengutronix.de> [140111 06:03]:
> > The PMIC is using usb0 vbus line as power source. It is also connected
> > to the am335x processor as vbus sense. But there is no possibility to
> > pullup usb0 vbus to operate as host. This patch fixes the dr_mode of usb0.
> 
> That's the MUSB? AFAIK it's not possible to operate MUSB in peripheral
> only mode because the hardware does what it wants based on the ID
> pin state.

Yes that's MUSB. The am335x reference manual describes that it is
possible to force peripheral/host mode by setting bit 7 (IDDIG_MUX) in
register USBnMODE to 1. Then it uses the bit written in bit 8 (IDDIG) of
register USBnMODE to set host/peripheral mode.

I am not sure if the driver supports it yet but I think the DTS should
contain the correct mode nevertheless, especially to avoid starting the
otg loops in the musb driver.

Regards,

Markus

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