33 lines
1.3 KiB
Plaintext
33 lines
1.3 KiB
Plaintext
Introduction
|
|
============
|
|
|
|
Gadget serial driver is divided into two parts.
|
|
1. f_serial.c : Interacts with USB Gadget Layer
|
|
2. u_serial.c : Interacts with TTY Layer
|
|
|
|
Gadget sdio driver adds capability to interact with SDIO Layer in
|
|
case modem device is inter-connected with sdio interface.
|
|
|
|
S/W Description
|
|
===============
|
|
Gadget SDIO driver is a simple bridge driver between usb serial
|
|
gadget and sdio abstraction layer. It registers with sdio
|
|
abstraction layer with read/write call backs and provides
|
|
USB connect/disconnect call backs usb gadget serial driver.
|
|
|
|
|
|
S/W Control Flow:
|
|
=================
|
|
Driver maintains two sdio channels, one for data and one for control.
|
|
Data pipe is dedicated sdio channel where as control is a muxed channel.
|
|
Incase of sdio control pipe, driver registers for control information
|
|
chagnes from modem side. Whenever new information is available, it
|
|
would queue a interrupt endpoint w/ new info. Laptop can also send the
|
|
DTR and RTS information as part of SET Encapsulated command.
|
|
|
|
Data pipe of sdio channel also has notification mechanism to indicate
|
|
the READ/WRITE availability. When READ is available on SDIO pipe,
|
|
driver would read the data and hands it over to USB In ept and when
|
|
it receives the data from USB driver would queue the same to SDIO
|
|
channel(if write buffers are available).
|