modifying line state manually on ttyS

[Michael Buesch <freesoftwaredeveloper@web.de>]

Hi.

I have asked in many other mailing-lists, but I got no good
solution for my problem, so I try to ask here, although it may
not be the exaclty correct list for it.

I have developed my own device, that is connected to ttyS0.
To talk to my device, I need to set the state of the TxD line
manually to either 0 or 1 (+12v or -12v). What I try to say is,
I don't want to write a whole byte to the port, but only one single
bit, that then stays persistent on the line, until I reset its state.
Better sayed, I want to handle TxD line, like it's possible for
DTR-line for example.

Is kernel-support by the ttyS driver present for this, or do I
have to write my own driver for my device. I'm trying to
implement the driver in user-space, but I didn't find a solution
to set linestate of TxD.

Regards
Michael Buesch.

-- 
My homepage: http://www.8ung.at/tuxsoft
fighting for peace is like fu**ing for virginity