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SubjectRe: Re hardware handshake support for 2.0/2.2/2.4
On Fri, Aug 04, 2000 at 02:18:52PM +0100, Alan Cox wrote:
> > I been asked to put togther some driver support for some of these cards
> > and was thinking about an ioctl, but is there a std which overs this?
>
> For a radio modem I got involved with the RS485 was just done in userspace
> via the modem control ioctls

There are different h/w arrangement for RS485 IIRC though, these cards give
the folowing options:-
Half-duplex auto-gated,
Half-duplex RTS switch, tx when RTS high[1]
Half-duplex RTS switch, tx when RTS low[1]
Both Tx/Rx Disabled.
Tx only
Rx Only
Full Duplex.

I guess you were using either option 2 or 3 with that.

These various modes are handled by the hardware and you can switch
them just be setting the register approriately. Assuming kernel
or CAP_SYS_RAWIO (is this the right one?).

TTFN

[1] Just to confuse matters one set of these cards then goes and uses DTR
instead of RTS.
--
Roger
Think of the mess on the carpet. Sensible people do all their
demon-summoning in the garage, which you can just hose down afterwards.
-- damerell@chiark.greenend.org.uk

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