Hi > -----Original Message----- > From: Oliver Neukum [mailto:oneukum@xxxxxxxx] > Sent: 2018年5月3日 17:18 > To: Jun Li <jun.li@xxxxxxx>; robh+dt@xxxxxxxxxx; > heikki.krogerus@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; > linux@xxxxxxxxxxxx > Cc: gsomlo@xxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Peter Chen > <peter.chen@xxxxxxx>; shufan_lee@xxxxxxxxxxx; a.hajda@xxxxxxxxxxx; > cw00.choi@xxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > linux-usb@xxxxxxxxxxxxxxx > 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:oneukum@xxxxxxxx] > > > Sent: 2018年5月3日 15:27 > > > To: Jun Li <jun.li@xxxxxxx>; robh+dt@xxxxxxxxxx; > > > heikki.krogerus@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; > > > linux@xxxxxxxxxxxx > > > Cc: gsomlo@xxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Peter Chen > > > <peter.chen@xxxxxxx>; shufan_lee@xxxxxxxxxxx; > a.hajda@xxxxxxxxxxx; > > > cw00.choi@xxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > > > linux-usb@xxxxxxxxxxxxxxx > > > 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 ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
