From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25F5E18EC1; Fri, 15 Dec 2023 22:14:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.de header.i=linosanfilippo@gmx.de header.b="hXhOymDR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1702678425; x=1703283225; i=linosanfilippo@gmx.de; bh=C06XXkJK7IZiZ0MT6MWFhD5Flfb1WACPBxOdMeCa4xw=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From: In-Reply-To; b=hXhOymDR1W83ZjnKPjT5KlB+DYtmkxBITeBaeFrNw3mHr6qzH3Khl0+cqN8CKApY eICFT/Hfydvt+M1uJ3vEi7gBLY71ttn2QuglHIIjmcF6hX431d5a342M+79Sb1TF5 CuiFiLq1jyobFh6a3pbM4oNPn13q9DUYGo2lxLfVfuAGNnI44den2Ixyk5UmNy/Fe Z3wRSvfdYM5xj6LNZPP9aE1SQDqZfXzOXU+pkj1JLQrspU/1dhhzOo4/86E1iLb+t 2vr24ANbuDwTkJ6tVh6mU3PVCeF29Rfr8MZ2cDbLmtIcLcjS43ldAwUehhaIdKTRB jzmmtOPj+D92jfuG/w== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.2.42] ([84.162.1.150]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1N0oBr-1rQRZ60MAH-00wlzn; Fri, 15 Dec 2023 23:13:45 +0100 Message-ID: <1b0af20c-8a2c-46ba-ab2e-d598b65fd0c1@gmx.de> Date: Fri, 15 Dec 2023 23:13:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] dt-bindings: serial: rs485: add rs485-mux-gpios binding Content-Language: en-US To: Christoph Niedermaier , Crescent CY Hsieh , Andy Shevchenko Cc: Lukas Wunner , Rasmus Villemoes , Greg Kroah-Hartman , Jiri Slaby , Rob Herring , Krzysztof Kozlowski , Conor Dooley , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-serial@vger.kernel.org" , =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , "brenda.streiff@ni.com" , Tomas Paukrt References: <20231120151056.148450-1-linux@rasmusvillemoes.dk> <20231120151056.148450-2-linux@rasmusvillemoes.dk> <20231122145344.GA18949@wunner.de> <3b8548b1-b8a9-0c9e-4040-5cfda06a85c6@gmx.de> <5c140498-69e3-4187-8703-db0c41e7ca89@gmx.de> From: Lino Sanfilippo In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:DPmv0J/k0HzTMbwTgxlSJfkOv4Ktn/RCfR7VD9yMFQAhDj2mM7o uxQHhjhrdmjTZh75hXxE0RbAq9ucl7RIgehxEi6jO72FJUTlYyA/nHRfX3gshPGfjFdE0zl RdO9rHODzl6delVvUFGVCVwZtTAygSdqXQCv4OnDp3K2RVrH5MfscljgRxE3StmFRzStyNZ qtsuUKm0S1QJ2VQS7lhJQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:oiUTxF7LW/I=;01gP3CrURX/RACgl6u/hm4kcUjB hahsEkwwPDj+bL+6RFpCqdSOUCMivMkVRTBxjBXCIpVDk1YnsY+Qjxcy//vsoC+Fuyuqjyg+v qys9FiGDbQ89zVmGl1KNGvYJPEvh5RZg5vYP0H7Nsey1UEc1HlBBYjoS05d3ZdIc52hyElBcV F5mFo2FWQrG46ObwtdsfjyLUIlrwH7TezyA571sUx9KGzIezsqUaA9YYjynVF1GyEI3YINU7b AC6J9RN2XGw4VKmwucifG5nRw5f0UUrLD1hjxx4HSY+CsEhu2VNKzhM54ibNLHdLlGrrPhdKE MRxNxhw2RbHzm+/AT6w6PpoqqMu7qXXdzbyCVm+R5SsrU8jQGtff3+YWXEPin8wk6oP3OlmcE J4QesO1qu3rXpFfJrSiOLrQ5bCLwDFNdHQgpmCdJUQLHUCqolHoLVM1QdfJ0DABd6htQAu3cW zhOxhcoPwIPTNIjmz/6xeAyN2z3l+m6DwalMwJOgPB+CBuToATIWQnX27UzTFssebTyZUjxx2 16GkjF0VJoJd3xds1LamQOO2IsMBZbUzNNnSP+TG9p+WornZE4JROYNx5MmcnCZPfr9+TDV+U irRGE0Fhnq7Wh0HzB/qBsTopr0QuD2TGrr4HMoLF5XLsciKf6HGfi0XOSo9nocpLhWPo99wwA E/OpdfmVOv9lbVZXHCW6oqQuzJZEZGR/4YKDK+ey1m0pDCVwxEkc1bI8bp1y4mGHv/nAupOMJ qx0Lh7VhUH6cdjXVj/v9+MBwCj4eiVJvX9OoNbNciq8YitBz9C2bIPVgAh8vCmzRAxPIKmGIu nol3VT+rJrVGUJww/OC5nUxPZc14pR1ptI/0c/C8JXWSKHPv8LzElce8R/ZsivwvNbiQEQCty 5lcomLZeIUOkfD1ESG549A9alZgv7lPHXJN0Qx86feWx88VXOIELXqVyGCE7HmWivFT4tTq0y ji57uA== Hi Christoph, On 14.12.23 15:50, Christoph Niedermaier wrote: > > I think we don't need to distinguish, because for a full duplex RS-485 > transceiver also needs RTS control. For example look at the full duplex > RS-485 transceiver ADM3491E [1]. It's a full duplex transceiver (A/B and= Z/Y) > that has DE (Driver enable) and DI (Driver Input) pins for controlling T= X. I > think the RS-485 master doesn't need it. The DE pin could also be set > permanently high. But if we have more than one RS-485 slaves it's needed= to > avoid blocking of each other on the receiving wires of the RS-485 master= . > Thanks for the explanation. So while still needed for the slaves, in case = of the RS485 master the RTS control is not needed, right? Is this something that = userspace should be able to configure? It could be set by clearing both the RTS_ON_S= END and RTS_AFTER_SEND flag (only if the driver supports this special RS485 mode, = of course). Regards, Lino