From: Sergei Shtylyov Date: Wed, 17 Dec 2014 11:35:30 +0000 Subject: Re: [PATCH] usb: hcd: add OTG ID signal sensing Message-Id: <54916A82.4010105@cogentembedded.com> List-Id: References: <3663198.HSrURZGche@wasted.cogentembedded.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Chen , "gregkh@linuxfoundation.org" , "linux-usb@vger.kernel.org" Cc: "linux-sh@vger.kernel.org" , "linux-kernel@vger.kernel.org" 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