From 228919a9bd2b2c9faed411175174c8b49a0dde92 Mon Sep 17 00:00:00 2001 From: Badhri Jagan Sridharan Date: Mon, 31 Aug 2015 21:36:07 -0700 Subject: usb: phy: Dual role sysfs class definition This CL adds a new class to monitor and change dual role usb ports from userspace. The usb phy drivers can register to the dual_role_usb class and expose the capabilities of the ports. The phy drivers can decide on whether a specific attribute can be changed from userspace by choosing to implement the appropriate callback. Cherry-picked from https://android-review.googlesource.com/#/c/167310/ Signed-off-by: Badhri Jagan Sridharan Bug: 21615151 Change-Id: Id1c4aaa97e898264d7006381a7badd029b5d9789 --- .../ABI/testing/sysfs-class-dual-role-usb | 71 ++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-dual-role-usb (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-class-dual-role-usb b/Documentation/ABI/testing/sysfs-class-dual-role-usb new file mode 100644 index 000000000000..a900fd75430c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-dual-role-usb @@ -0,0 +1,71 @@ +What: /sys/class/dual_role_usb/.../ +Date: June 2015 +Contact: Badhri Jagan Sridharan +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 +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 +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 +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 +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 +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". -- cgit v1.2.3