1Android USB devices (eg. /sys/class/android_usb/android0/) 2 3What: /sys/class/android_usb/<android_device>/state 4Date: Feb 2024 5Contact: Neill Kapron <nkapron@google.com> 6Description: 7 The state of the USB connection. This attribute is likely 8 redundant with the /sys/class/UDC/state attribute, and should 9 be deprecated/removed when userspace can be refactored. 10 Change on the state will also generate uevent KOBJ_CHANGE on 11 the port with the new state included in the message as 12 "USB_STATE=<STATE>". Note this is not the correct usage of 13 uevents, but necessary due to the requirement to maintaine 14 userspace API compatibility. 15 16 Valid values: CONNECTED, DISCONNECTED, CONFIGURED 17 18Android USB MIDI Function devices (eg. /sys/class/android_usb/androidN/f_midi/) 19 20What: /sys/class/android_usb/<android_device>/f_midi/alsa 21Date: Feb 2024 22Contact Neill Kapron <nkapron@google.com> 23Description: 24 The PCM card and device numbers created by the f_midi driver. 25 This is not the correct use of sysfs due to passing multiple 26 values through a single file, which is directly against the 27 "one value per file" nature of sysfs, however Android userspace 28 code currently relies on this functionality as-is. 29 30 Valid values: card and device numbers in the format of 31 <PCM_card_number> <device number>", or "-1 -1" if the attr 32 is read prior to binding the f_midi device. 33