Assume that we have a serial device /dev/ttyS0
with a deafult speed 9600 bps.
Say, we have changed its speed to, for example, 4800 bps using cfsetospeed
.
Now, the speed of writing to the wire must be slower.
Where is the source code that does this operation? Which part of the operating system controls this speed? Custom driver, tty driver or what? And how, by setting clock speed or delaying?
It may be in the driver, but I couldn't find it. For example, could anyone show me the place in RocketPort driver?