72 lines
2.6 KiB
Text
72 lines
2.6 KiB
Text
|
What: /sys/class/dual_role_usb/.../
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
Provide a generic interface to monitor and change
|
||
|
|
the state of dual role usb ports. The name here
|
||
|
|
refers to the name mentioned in the
|
||
|
|
dual_role_phy_desc that is passed while registering
|
||
|
|
the dual_role_phy_intstance through
|
||
|
|
devm_dual_role_instance_register.
|
||
|
|
|
||
|
|
What: /sys/class/dual_role_usb/.../supported_modes
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
This is a static node, once initialized this
|
||
|
|
is not expected to change during runtime. "dfp"
|
||
|
|
refers to "downstream facing port" i.e. port can
|
||
|
|
only act as host. "ufp" refers to "upstream
|
||
|
|
facing port" i.e. port can only act as device.
|
||
|
|
"dfp ufp" refers to "dual role port" i.e. the port
|
||
|
|
can either be a host port or a device port.
|
||
|
|
|
||
|
|
What: /sys/class/dual_role_usb/.../mode
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
The mode node refers to the current mode in which the
|
||
|
|
port is operating. "dfp" for host ports. "ufp" for device
|
||
|
|
ports and "none" when cable is not connected.
|
||
|
|
|
||
|
|
On devices where the USB mode is software-controllable,
|
||
|
|
userspace can change the mode by writing "dfp" or "ufp".
|
||
|
|
On devices where the USB mode is fixed in hardware,
|
||
|
|
this attribute is read-only.
|
||
|
|
|
||
|
|
What: /sys/class/dual_role_usb/.../power_role
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
The power_role node mentions whether the port
|
||
|
|
is "sink"ing or "source"ing power. "none" if
|
||
|
|
they are not connected.
|
||
|
|
|
||
|
|
On devices implementing USB Power Delivery,
|
||
|
|
userspace can control the power role by writing "sink" or
|
||
|
|
"source". On devices without USB-PD, this attribute is
|
||
|
|
read-only.
|
||
|
|
|
||
|
|
What: /sys/class/dual_role_usb/.../data_role
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
The data_role node mentions whether the port
|
||
|
|
is acting as "host" or "device" for USB data connection.
|
||
|
|
"none" if there is no active data link.
|
||
|
|
|
||
|
|
On devices implementing USB Power Delivery, userspace
|
||
|
|
can control the data role by writing "host" or "device".
|
||
|
|
On devices without USB-PD, this attribute is read-only
|
||
|
|
|
||
|
|
What: /sys/class/dual_role_usb/.../powers_vconn
|
||
|
|
Date: June 2015
|
||
|
|
Contact: Badhri Jagan Sridharan<badhri@google.com>
|
||
|
|
Description:
|
||
|
|
The powers_vconn node mentions whether the port
|
||
|
|
is supplying power for VCONN pin.
|
||
|
|
|
||
|
|
On devices with software control of VCONN,
|
||
|
|
userspace can disable the power supply to VCONN by writing "n",
|
||
|
|
or enable the power supply by writing "y".
|