Hi, I am trying to understand usb composite gadget drivers. I tried to make a block diagram for understanding a communication flow. Attached a text file with this email. This is based on source code and haven't verified on real target yet. Please, point me if I misunderstood anything. Thanks lot, for the help. Thanks and Regards, Shivdas Gujare
,------------------,
| USER |
| application |
'------------------'
/|\
|
USER \|/
=========================================================================================================================================
KERNEL /|\
|
\|/
,------------------,
| drivers/char/ |
tty_layer | tty_io.c |
'------------------'
/|\
|
struct (1) | open/close/read/write (9)
usb_gadget_driver struct |
(2) usb_composite_driver \|/
,---------------------, ,---------------, usb_composite_ ,----------------------, (4) ,----------------------,
| | (3) | | register | | gserial_setup | u_serial.c |
| USB Device |<----------------| composite.c |<---------------| serial.c |-------------->| |
| Controller driver | usb_gadget_ | | usb_add_ | | struct | struct |
| | register_driver | | config | | tty_driver | tty_operations |
'---------------------' '---------------' (5) '----------------------' '----------------------'
/|\ /|\ /|\ struct usb_configuration /|\
| | \ (serial_bind_config) |
| \ \ / | \ (6) | Notify USB status to tty_io
\ \ \ (6)/ |(6) \ |
\ \ \ / | \ gserial_connect/disconnect [active/inactive] (8)
\ \ \ / | \__gser_bind_config__ | [same for f_acm.c and f_obex.c]
\ \ \ / | \ |
\ \ \_________/____________|___usb_add_function______ \ |
\ \ / | (7) \ \ |
\ \_(7)usb_add_function__ | \ \ |
\ _______/ \ | \ \ |
(7) usb_add_function |acm_bind_config \ |obex_bind_config \ \ |
\ \|/ \ \|/ \ \|/ |
,---------------, ,---------------, ,---------------,
| | | | | |
| f_acm.c | | f_obex.c | | f_serial.c |
| | | | | |
'---------------' '---------------' '---------------'
struct usb_function struct usb_function struct usb_function
