tag	line	file	source code
callback	364	include/linux/tty.h	void (*callback)(void * data), void * callarg);
callback	1487	kernel/chr_drv/tty_io.c	void (*callback)(void * data), void * callarg)
callback	1516	kernel/chr_drv/tty_io.c	tty->write_data_callback = callback;