Hi > -----Original Message----- > From: Oliver Neukum [mailto:oneu...@suse.com] > Sent: 2018年5月3日 17:18 > To: Jun Li <jun...@nxp.com>; robh...@kernel.org; > heikki.kroge...@linux.intel.com; gre...@linuxfoundation.org; > li...@roeck-us.net > Cc: gso...@gmail.com; dl-linux-imx <linux-...@nxp.com>; Peter Chen > <peter.c...@nxp.com>; shufan_...@richtek.com; a.ha...@samsung.com; > cw00.c...@samsung.com; devicet...@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, 08:35 +0000 schrieb Jun Li: > > Hi > > > -----Original Message----- > > > From: Oliver Neukum [mailto:oneu...@suse.com] > > > Sent: 2018年5月3日 15:27 > > > To: Jun Li <jun...@nxp.com>; robh...@kernel.org; > > > heikki.kroge...@linux.intel.com; gre...@linuxfoundation.org; > > > li...@roeck-us.net > > > Cc: gso...@gmail.com; dl-linux-imx <linux-...@nxp.com>; Peter Chen > > > <peter.c...@nxp.com>; shufan_...@richtek.com; > a.ha...@samsung.com; > > > cw00.c...@samsung.com; devicet...@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.
Could you please point me the "detection logic" of typec spec chapter 4 you are referring to? > 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. I see there is dr_swap handling for data role swap in tcpm already, maybe I misunderstood the "logic" you want here. Regards Li Jun > > Regards > Oliver
