1What: /sys/class/dual_role_usb/.../ 2Date: June 2015 3Contact: Badhri Jagan Sridharan<badhri@google.com> 4Description: 5 Provide a generic interface to monitor and change 6 the state of dual role usb ports. The name here 7 refers to the name mentioned in the 8 dual_role_phy_desc that is passed while registering 9 the dual_role_phy_intstance through 10 devm_dual_role_instance_register. 11 12What: /sys/class/dual_role_usb/.../supported_modes 13Date: June 2015 14Contact: Badhri Jagan Sridharan<badhri@google.com> 15Description: 16 This is a static node, once initialized this 17 is not expected to change during runtime. "dfp" 18 refers to "downstream facing port" i.e. port can 19 only act as host. "ufp" refers to "upstream 20 facing port" i.e. port can only act as device. 21 "dfp ufp" refers to "dual role port" i.e. the port 22 can either be a host port or a device port. 23 24What: /sys/class/dual_role_usb/.../mode 25Date: June 2015 26Contact: Badhri Jagan Sridharan<badhri@google.com> 27Description: 28 The mode node refers to the current mode in which the 29 port is operating. "dfp" for host ports. "ufp" for device 30 ports and "none" when cable is not connected. 31 32 On devices where the USB mode is software-controllable, 33 userspace can change the mode by writing "dfp" or "ufp". 34 On devices where the USB mode is fixed in hardware, 35 this attribute is read-only. 36 37What: /sys/class/dual_role_usb/.../power_role 38Date: June 2015 39Contact: Badhri Jagan Sridharan<badhri@google.com> 40Description: 41 The power_role node mentions whether the port 42 is "sink"ing or "source"ing power. "none" if 43 they are not connected. 44 45 On devices implementing USB Power Delivery, 46 userspace can control the power role by writing "sink" or 47 "source". On devices without USB-PD, this attribute is 48 read-only. 49 50What: /sys/class/dual_role_usb/.../data_role 51Date: June 2015 52Contact: Badhri Jagan Sridharan<badhri@google.com> 53Description: 54 The data_role node mentions whether the port 55 is acting as "host" or "device" for USB data connection. 56 "none" if there is no active data link. 57 58 On devices implementing USB Power Delivery, userspace 59 can control the data role by writing "host" or "device". 60 On devices without USB-PD, this attribute is read-only 61 62What: /sys/class/dual_role_usb/.../powers_vconn 63Date: June 2015 64Contact: Badhri Jagan Sridharan<badhri@google.com> 65Description: 66 The powers_vconn node mentions whether the port 67 is supplying power for VCONN pin. 68 69 On devices with software control of VCONN, 70 userspace can disable the power supply to VCONN by writing "n", 71 or enable the power supply by writing "y". 72