Re: [PATCH] usb: hcd: add OTG ID signal sensing

From: Sergei Shtylyov
Date: Wed Dec 17 2014 - 06:35:38 EST


Hello.

On 12/17/2014 5:08 AM, Peter Chen wrote:

On the Renesas R8A7791 SoC based boards there's MAX3355 USB OTG chip and
mini-AB USB connector corresponding to USB port 0 driven either by EHCI/OHCI
or Renesas USBHS gadget controller. And we'd like the host/gadget drivers to
work based on the cable type connected. An 'extcon' driver for MAX3355 has
been written, so we only need to bind to it via device tree which I'm doing in
this patch.

I wasn't able to find a solution better than checking the cable type at the host
driver probe time and refusing to drive a host if B-cable is connected.

You may need a dual-role/otg driver to do it, which can enable host/device function
according to ID pin.

It would have been too good if I had a dual-role controller. :-)
But I have what I have. IIUC, such configuration (OHCI and UDC sharing a USB port) has been used on OMAP1.

WBR, Sergei

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