From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1525339063.12348.4.camel@suse.com> Subject: Re: [PATCH v5 01/14] dt-bindings: connector: add properties for typec From: Oliver Neukum Date: Thu, 03 May 2018 11:17:43 +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> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Donnerstag, den 03.05.2018, 08:35 +0000 schrieb Jun Li: > Hi > > -----Original Message----- > > From: Oliver Neukum [mailto:oneukum@suse.com] > > Sent: 2018年5月3日 15:27 > > 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 > > Subject: Re: [PATCH v5 01/14] dt-bindings: connector: add properties for typec > > > > Am Donnerstag, den 03.05.2018, 08:24 +0800 schrieb Li Jun: > > > +Optional properties for usb-c-connector: > > > +- power-role: should be one of "source", "sink" or "dual"(DRP) if > > > +typec > > > +  connector has power support. > > > +- try-power-role: preferred power role if "dual"(DRP) can support > > > +Try.SNK > > > +  or Try.SRC, should be "sink" for Try.SNK or "source" for Try.SRC. > > > +- data-role: should be one of "host", "device", "dual"(DRD) if typec > > > +  connector supports USB data. > > > > Hi, > > > > is this really correct? > > > > 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. I can see no reason why you couldn't build a port that can be switched between the data roles but not implement that logic. Regards Oliver