From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:58618 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753312AbdC2Fwc (ORCPT ); Wed, 29 Mar 2017 01:52:32 -0400 From: Felipe Balbi To: Yoshihiro Shimoda Cc: "gregkh\@linuxfoundation.org" , "linux-usb\@vger.kernel.org" , "linux-renesas-soc\@vger.kernel.org" Subject: RE: [PATCH 1/4] usb: gadget: udc: renesas_usb3: add sysfs "role" to set "b-device" mode In-Reply-To: References: <1490702004-8167-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> <1490702004-8167-2-git-send-email-yoshihiro.shimoda.uh@renesas.com> <87efxhhahj.fsf@linux.intel.com> Date: Wed, 29 Mar 2017 08:52:12 +0300 Message-ID: <87d1d0fx4j.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi, Yoshihiro Shimoda writes: > Hi Felipe-san, > >> From: Felipe Balbi, Sent: Tuesday, March 28, 2017 9:06 PM >> >> Hi, >> >> Yoshihiro Shimoda writes: >> > Sadly, to change the role ("host" and "peripheral") of USB3.0 DRD >> > controller on R-Car Gen3, software has to set the DRD_CON register >> > which is included in a usb3.0 peripheral controler's register. >> > To simply implementation, the previous code always set peripheral mode >> > as hardcoded. However, to support usb role swap in the future, >> > the hardcoded is not good. So, this patch adds sysfs "role" to set >> > the mode by a user. >> > After applied this patch, since the DRD controller will act as host >> > mode after probed, a user needs to change the mode via the sysfs. >> > >> > Signed-off-by: Yoshihiro Shimoda >> >> in patch 3, you add extcon to monitor ID and VBUS pins. Do you really >> need this sysfs file at all? > > Yes. This is because this "role" sysfs file cannot monitor the ID and VBUS pins. > The "role" only monitors the mode which is "host" or "peripheral". Right, I understand it can't monitor the state of ID/VBUS, but do you have a usecase for that file that's not covered by the other patches in the series? :-) If you want to force renesas controller to peripheral mode, then shouldn't you use dr-mode device_property() instead? -- balbi