[BRLTTY] Inka's non-standard flow control

[Nicolas Pitre]

On Mon, 24 Apr 2006, Samuel Thibault wrote:

> Nicolas Pitre, le Mon 24 Apr 2006 09:24:50 -0400, a écrit :
> > Oh really?  All I've seen about people wanting to use RS425 for example 
> > have been told by RMK to do it in user space.
> 
> Mmm, this was in another thread then. Here is a quote from 7th Oct 2004:
> 
> «
> > Right now that poses a challenge but if drivers were to implement
> > ldisc->modem_change() or a similar callback for such events an ldisc
> > could then handle many of the grungy suprises and handle them once and
> > in one place.
> 
> To me at least that sounds like a good solution.  I can't help but
> wonder whether moving some of the usual modem line status change
> processing should also be moved into the higher levels.

Oh of course and I fully agree with that.  This was proposed, for 
example, to support some foldable PDA keyboards that uses CTS/RTS in a 
completely awkward way and doing so would have allowed for such a 
keyboard to have a driver to be implemented as a serial line discipline.  
It didn't happen yet and afs far as I know support for said keyboard is 
still implemented as an ugly hack to the SA1100 serial driver in the 
2.4.x CVS on handhelds.org.

But if the Inka handshake can be done from user space allowing to be 
available on other platforms besides Linux as well this is certainly the 
best way to go about it.


Nicolas