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