From: Wolfram Sang <w.sang@pengutronix.de>
To: Tomas Lastovicka <tomas.lastovicka@gmail.com>
Cc: linux-serial@vger.kernel.org
Subject: Re: RS-485 automatic RTS toggle in Linux (on Winbond W83627UHG)
Date: Tue, 29 Nov 2011 23:20:02 +0100 [thread overview]
Message-ID: <20111129222002.GA12314@pengutronix.de> (raw)
In-Reply-To: <CAFnDbmAAZZFNJAc=Y92xrkUujemTK63_2-H3TVkvbjVrsjUKgg@mail.gmail.com>
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> Unless i have overlooked something, i do not see how to toggle the
> automatic RTS mode from W83627UHG's datasheet. Have you found it?
Yes, searching for '485' gives you all the info you need (if we got the same
datasheet).
> Regarding 2.6.38+ drivers, Atmel supports RS485 on the hardware level
> and Etrax is handling the RTS toggling directly from the driver. I
Hardware level is the only official supported way in Linux. Software toggling
can easily fail due to preemption.
> guess this is what i will finally have to do, i.e. to toggle RTS from
> the driver myself.
Why? If the hardware has support?
> I am surprised that the RTS toggling issue for RS485 in Linux is
> around for quite a while.
It has come a long way, but all you need is there now (except for software
based direction control, see above).
Regards,
Wolfram
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2011-11-29 22:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-29 17:20 RS-485 automatic RTS toggle in Linux (on Winbond W83627UHG) Tomas Lastovicka
2011-11-29 17:57 ` Wolfram Sang
2011-11-29 22:13 ` Tomas Lastovicka
2011-11-29 22:20 ` Wolfram Sang [this message]
2011-11-29 22:25 ` Tomas Lastovicka
2011-11-29 22:36 ` Wolfram Sang
2011-11-29 23:15 ` Tomas Lastovicka
2011-12-07 11:58 ` Tomas Lastovicka
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