Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757919AbcKCQfx (ORCPT ); Thu, 3 Nov 2016 12:35:53 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:60828 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539AbcKCQfw (ORCPT ); Thu, 3 Nov 2016 12:35:52 -0400 Subject: Re: [PATCH v3 3/5] dt/bindings: Add a new property to DA8xx USB PHY To: Alexandre Bailon , , , References: <1478186765-19840-1-git-send-email-abailon@baylibre.com> <1478186765-19840-4-git-send-email-abailon@baylibre.com> CC: , , , From: Kishon Vijay Abraham I Message-ID: Date: Thu, 3 Nov 2016 22:04:48 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1478186765-19840-4-git-send-email-abailon@baylibre.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1995 Lines: 45 Hi, On Thursday 03 November 2016 08:56 PM, Alexandre Bailon wrote: > The USB PHY is able to operate in OTG, host or peripheral. > Some board may be wired to work act only as host or peripheral. > In such case, the dr_mode property of controller must be set to > host or peripheral. But doing that will also configure the PHY > in host or peripheral mode whereas OTG is able to detect which > role the USB controller should take. > The PHY's host or peripheral mode are actually only useful when > hardware doesn't allow OTG to detect it's role. > > Add the usb20_force_mode property to force the PHY to operate > in host or peripheral mode. I think we do just that if we populate dr_mode with host or peripheral. Why do we need another property to control dr_mode property? > When usb20_force_mode is used, dr_mode should also be configured > to host or peripheral. > The controller uses dr_mode to configure itself, but the phy use > it to get the mode to use to configure the PHY mode. > > Signed-off-by: Alexandre Bailon > --- > Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt b/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt > index c26478b..9fc87fb 100644 > --- a/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt > +++ b/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt > @@ -4,6 +4,11 @@ Required properties: > - compatible: must be "ti,da830-usb-phy". > - #phy-cells: must be 1. > > +Optional properties: > +- usb20-force-mode: Force the phy to operate in same mode than the USB OTG controller. > + It should only be defined if the hardware is not capable correctly > + detect the role of USB by using VBUS and ID pin. >From what I understand from the previous patch, if VBUS sense and the session end comparator is enabled, the controller can work in host mode or device mode. Thanks Kishon