From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: RS-485 automatic RTS toggle in Linux (on Winbond W83627UHG) Date: Tue, 29 Nov 2011 23:20:02 +0100 Message-ID: <20111129222002.GA12314@pengutronix.de> References: <20111129175728.GH5455@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cNdxnHkX5QqsyA0e" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:50167 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752713Ab1K2WUH (ORCPT ); Tue, 29 Nov 2011 17:20:07 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Tomas Lastovicka Cc: linux-serial@vger.kernel.org --cNdxnHkX5QqsyA0e Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > 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 toggli= ng 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 --=20 Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | --cNdxnHkX5QqsyA0e Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAk7VWpIACgkQD27XaX1/VRvIUACgnX92dFgJ2IxR0IAINrwb4n+l TJkAn2aSO3jFGvjYtgZH+8Ez4EvK7hun =fvpa -----END PGP SIGNATURE----- --cNdxnHkX5QqsyA0e--