I want to load my custom service to show orangepi zero as three devices on the host PC. But as the UDC  ( /sys/class/udc/musb-hdrc.1.auto) is being used by another service which is probably the builtin service using udc to show orangepi as:
 

Bus 001 Device 048: ID 0525:a4a7 Netchip Technology, Inc. Linux-USB Serial Gadget (CDC ACM mode)  

 I want to disable that service so that my custom service can use the UDC for the required purpose.

 

This is the command:

echo "$(ls /sys/class/udc/)" > UDC

 

and this is the error:

echo: write error: Device or resource busy

 

"ls /sys/class/udc" has the file musb-hdrc.1.auto

 

and UDC is in the folder /sys/kernel/config/usb-gadget/< custom name>/    ,   which is created using a bash script

 

Regards,

Sumit 

Solved the problem (edited)

Disabled usb gadget service of orangepi zero
`sudo  /sbin/rmmod g_serial`  (edited)
then 
 `sudo bash create-gadget.sh` 
link to solution: https://vjordan.info/log/fpga/nanopi-neo-usb-otg-with-armbian-mainline-4x-kernel.html

 

after `rmmod g_serial` , it can be verified on the host pc by `lsmod`.

 

On the orangepi:
 `ls /dev/hid*`  lists the hid device ports (hidraw1, hadraw2 ... ) and gadget port (hidg0)

 

 

just curious : what are you doing this for?

may be useful, usb doesn't need to be simply serial, but that's defacto

it can work as usb-audio, usb-storage, usb-video, usb-ethernet, usb-hid (keyboard, mouse, joystick, sensors etc), usb-serial, usb-dfu (device firmware upgrade), usb-mtp, etc etc

http://www.usb.org/developers/docs/devclass_docs/

but one would need to write the 'driver' on the board talking to the host for it