From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1525773790.24345.12.camel@suse.com> Subject: Re: [PATCH v5 01/14] dt-bindings: connector: add properties for typec From: Oliver Neukum Date: Tue, 08 May 2018 12:03:10 +0200 In-Reply-To: References: <1525307094-27402-1-git-send-email-jun.li@nxp.com> <1525307094-27402-2-git-send-email-jun.li@nxp.com> <1525332431.12348.1.camel@suse.com> <1525339063.12348.4.camel@suse.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit To: Jun Li , "robh+dt@kernel.org" , "heikki.krogerus@linux.intel.com" , "gregkh@linuxfoundation.org" , "linux@roeck-us.net" Cc: "gsomlo@gmail.com" , dl-linux-imx , Peter Chen , "shufan_lee@richtek.com" , "a.hajda@samsung.com" , "cw00.choi@samsung.com" , "devicetree@vger.kernel.org" , "linux-usb@vger.kernel.org" List-ID: Am Freitag, den 04.05.2018, 08:59 +0000 schrieb Jun Li: > > > > > Can one implement a device that can operate as either DFP or UFP, > > > > but not implements the dynamic role switch that a DRP must support? > > > > > > You mean a port with DRD on data but not DRP on power? > > > > > > The data-role is newly added as the data role is not coupled with > > > power > > > > No, I meant data role. As far as I can tell for a DRP you need to implement the > > detection logic described in chapter 4 of the spec. > > Could you please point me the "detection logic" of typec spec chapter 4 > you are referring to? Chapter 4.5.2.2, especially state diagramms 4.15 and 4.16 It just seems to me that a DRP and a physical port that can be switched between UFP and DFP are not the same thing, but can be implemented. Regards Oliver