Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758849AbcKCQxS (ORCPT ); Thu, 3 Nov 2016 12:53:18 -0400 Received: from vern.gendns.com ([206.190.152.46]:39296 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751019AbcKCQxR (ORCPT ); Thu, 3 Nov 2016 12:53:17 -0400 Subject: Re: [PATCH v3 3/5] dt/bindings: Add a new property to DA8xx USB PHY To: Alexandre Bailon , b-liu@ti.com, balbi@kernel.org References: <1478186765-19840-1-git-send-email-abailon@baylibre.com> <1478186765-19840-4-git-send-email-abailon@baylibre.com> Cc: kishon@ti.com, khilman@baylibre.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, nsekhar@ti.com From: David Lechner Message-ID: Date: Thu, 3 Nov 2016 11:53:14 -0500 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; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2038 Lines: 45 On 11/03/2016 10:26 AM, 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. Device tree describes the hardware, not the configuration, so this is not acceptable. Besides, this setting should not be fixed to one value anyway. > 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. > + > This device controls the PHY for both the USB 1.1 OHCI and USB 2.0 OTG > controllers on DA8xx SoCs. Consumers of this device should use index 0 for > the USB 2.0 phy device and index 1 for the USB 1.1 phy device. >