eva:/sys/class/android_usb/android0 $ ls -la
total 0
drwxr-xr-x 7 root   root      0 2019-06-13 18:18 .
drwxr-xr-x 3 root   root      0 2019-06-13 18:18 ..
drwxr-xr-x 3 root   root      0 2019-06-13 18:18 f_audio_source
drwxr-xr-x 3 root   root      0 2019-06-13 18:18 f_mass_storage
drwxr-xr-x 3 root   root      0 2019-06-13 18:18 f_midi
drwxr-xr-x 3 root   root      0 2019-06-13 18:18 f_rndis
-rw-rw---- 1 root   root   4096 2019-06-13 18:18 port_mode
drwxr-xr-x 2 root   root      0 2019-06-13 18:20 power
-r--r--r-- 1 root   root   4096 2019-06-13 18:18 state
lrwxrwxrwx 1 root   root      0 2019-06-13 18:20 subsystem -> ../../../../class/android_usb
-r--r--r-- 1 root   root   4096 2019-06-13 18:20 switch_index
-rw-rw-r-- 1 system system 4096 2019-06-13 18:18 switch_request
-rw-r--r-- 1 root   root   4096 2019-06-13 18:20 uevent

eva:/config/usb_gadget/g1/functions # ls -la
total 0
drwxr-xr-x 14 root root 0 2019-06-13 18:18 .
drwxr-xr-x  6 root root 0 2019-06-13 18:20 ..
drwxr-xr-x  2 root root 0 2019-06-13 18:18 accessory.gs2
drwxr-xr-x  2 root root 0 2019-06-13 18:18 audio_source.gs3
drwxr-xr-x  2 root root 0 2019-06-13 18:18 ffs.adb
drwxr-xr-x  2 root root 0 2019-06-13 18:18 ffs.hdb
drwxr-xr-x  2 root root 0 2019-06-13 18:18 hw_acm.hw_acm_DIAG
drwxr-xr-x  2 root root 0 2019-06-13 18:18 hw_acm.hw_acm_PCUI
drwxr-xr-x  2 root root 0 2019-06-13 18:18 hw_acm.hw_acm_modem
drwxr-xr-x  3 root root 0 2019-06-13 18:18 mass_storage.gs6
drwxr-xr-x  2 root root 0 2019-06-13 18:18 midi.gs5
drwxr-xr-x  3 root root 0 2019-06-13 18:18 mtp.gs0
drwxr-xr-x  3 root root 0 2019-06-13 18:18 ptp.gs1
drwxr-xr-x  3 root root 0 2019-06-13 18:18 rndis.gs4
eva:/config/usb_gadget/g1/functions #