usb_function_deactivate (9) - Linux Man Pages
usb_function_deactivate: prevent function and gadget enumeration
usb_function_deactivate - prevent function and gadget enumeration
int usb_function_deactivate(struct usb_function
- the function that isn't yet ready to respond
Blocks response of the gadget driver to host enumeration by preventing the data line pullup from being activated. This is normally called during bind() processing to change from the initial "ready to respond" state, or when a required resource becomes available.
For example, drivers that serve as a passthrough to a userspace daemon can block enumeration unless that daemon (such as an OBEX, MTP, or print server) is ready to handle host requests.
Not all systems support software control of their USB peripheral data pullups.
David Brownell <dbrownell [at] users.sourceforge.net>