Documentation/ABI/testing/sysfs-class-dual-role-usb

   1 What:           /sys/class/dual_role_usb/.../
   2 Date:           June 2015
   3 Contact:        Badhri Jagan Sridharan<badhri@google.com>
   4 Description:
   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
  12 What:           /sys/class/dual_role_usb/.../supported_modes
  13 Date:           June 2015
  14 Contact:        Badhri Jagan Sridharan<badhri@google.com>
  15 Description:
  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
  24 What:           /sys/class/dual_role_usb/.../mode
  25 Date:           June 2015
  26 Contact:        Badhri Jagan Sridharan<badhri@google.com>
  27 Description:
  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
  37 What:           /sys/class/dual_role_usb/.../power_role
  38 Date:           June 2015
  39 Contact:        Badhri Jagan Sridharan<badhri@google.com>
  40 Description:
  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
  50 What:           /sys/class/dual_role_usb/.../data_role
  51 Date:           June 2015
  52 Contact:        Badhri Jagan Sridharan<badhri@google.com>
  53 Description:
  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
  62 What:           /sys/class/dual_role_usb/.../powers_vconn
  63 Date:           June 2015
  64 Contact:        Badhri Jagan Sridharan<badhri@google.com>
  65 Description:
  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".