lkml.org 
[lkml]   [2006]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] SIIG 8-port serial boards support
On Fri, Feb 17, 2006 at 03:27:44PM -0600, Paul Fulghum wrote:
> Russell King wrote:
> >So, there are three distinct flow control scenarios:
>
> So I'm clear on how you interpret these,
> am I correct with the following?
>
> >- conventional RTS/CTS
> RTS active = ready to receive
> CTS active = allowed to send
>
> >- alternative RTS/CTS
> RTS active = on before send, off after send
> CTS active = allowed to send

I'll have to dig through my archives to confirm this one.

> >- RS485
> RTS active = on before send, off after send (RTS enables driver)
> CTS ignored (2 wire mode, no CTS)
>
> So maybe the extra control fields would be:
> CRTSONTX - RTS on before send, off after send
> CTXONCTS - wait for CTS before sending

That's a possibility, except that programs today expect CRTSCTS to
enable RTS/CTS flow control.

What I suggest is to use CRTSCTS to enable the chosen flow control
method. Then we have a set of cflag bits which describe the flow
control mode, eg CFLOWRS485, CFLOWMODEM, CFLOWALT (probably needs
better names.) CFLOWMODEM being the conventional mode should have
an all zeros value.

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-02-17 22:41    [W:0.303 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site