[asterisk-dev] Help for developing a channel driver module

[Gilles Mazoyer]

Hi

I'm developping a channel module to add support for telephony on modem 
HW553 running OpenWrt.
My project is hosted on github https://github.com/pgid69/bcm63xx-phone.
Today the channel seems to work but i'm not sure that it's very 
efficient.
So I wanted to known if there is guideline for developping a channel 
module
More specifically
- does my channel module must provide a file descriptor to Asterisk, 
used in ast_waitfor() ?
All channel modules but chan_local provide at least one file descriptor 
(calling ast_channel_set_fd());
- should my channel pass audio data that it receives as fast as possible 
to Asterisk (using ast_queue_frame()) or should it wait that asterisk 
call the read callback ?

Thank you for your help