From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6282FC46CD2 for ; Tue, 30 Jan 2024 23:02:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=77tU/rUxs2nzzhW/GeR6hLHtSG+lLnKlrd4tnonTZNQ=; b=n+5e5JAjZOmABT VAV4q0rKntPwNjYExASejGnnmc+0s3JnTwI2i/sEYznwh7rDp1eqaEmm0bnPuzjYWSRC+IqwE4WW9 nE6J9itgj86X1n+S/V7PYgEo7+eyIjZJUDtxbYq/jZfRRt8IUPT6/mad97DmoADMOeb8vOTtAGTJH r1grJ9eYrAxD2+O8Ai6hw2FB6wY/8eptcup5k6QSADdknBHSZA+ObOlw0fr+SjzFfYhFZenTaut0A svqTPX6AZvToa/nsXk1/6PKsfP2RKEKLonizQ7aRDO7nb8qeGLebjbjcWDy9X0P4lqobj34D0kB2B JSK+WLVo0sahXXALX0fA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUx7Z-00000000q8K-2wvY; Tue, 30 Jan 2024 23:02:25 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUx7X-00000000q7W-2V6p; Tue, 30 Jan 2024 23:02:24 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 0525161177; Tue, 30 Jan 2024 23:02:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D7FAC433F1; Tue, 30 Jan 2024 23:02:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706655742; bh=Q/5sVxq0UBbAMtH5axjn8/3c/o19Bpt/DiCP+LgTKhU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bFFzWkI23nEDrljXibfFpeh//ZhwiOaUzuVPkBQ2abO2/Y9SHQejdGt/YabotelJQ zi9/4pjDB+6508q+ONxNgxvAlj3y9j54UOIxYBvV6+sdgZIvDTqEqBQbgGBf0ly5zC ZLHiVvyOR2kz+RkZ2Y0XvD37h3WAEkdrxwH0Tgy4pGMD2XmUs4ev4Oje1ZkeMG58yz XL9n6vtKfCoTsoFTpvUdpkS2sA/oASkFLEpiBZvbgFwrLFGraThwDpZ8t/ihP0ZXrZ Guwib0fCCB/9i5WEUXw+doqTL8urbagZHfBMV+dgNE7fRoL5Csn3hprI0zPV39sdDr FRKUgu27RaEoA== Date: Tue, 30 Jan 2024 17:02:20 -0600 From: Rob Herring To: Farouk Bouabid Cc: Greg Kroah-Hartman , Jiri Slaby , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, quentin.schulz@theobroma-systems.com Subject: Re: [PATCH v5 3/6] dt-bindings: serial: add binding for rs485 rx-enable state when rs485 is disabled Message-ID: <20240130230220.GA2569797-robh@kernel.org> References: <20240126-dev-rx-enable-v5-0-5d934eda05ca@theobroma-systems.com> <20240126-dev-rx-enable-v5-3-5d934eda05ca@theobroma-systems.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240126-dev-rx-enable-v5-3-5d934eda05ca@theobroma-systems.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240130_150223_698544_99E5B0AC X-CRM114-Status: GOOD ( 17.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jan 26, 2024 at 06:27:44PM +0100, Farouk Bouabid wrote: > RS485 can have a receiver-enable gpio (rx-enable-gpios). When rs485 is s/gpio/GPIO/ > enabled, this gpio, if provided, must be driven active while receiving. > However when RS485 is disabled this gpio should not have an undefined > state. In that case, as DE and RE pins can be connected both to this gpio, > if its state is not properly defined, can cause unexpected transceiver > behavior. > This binding depend on rx-enable-gpios to be implemented. Sounds like a constraint: dependencies: rs485-rx-enable-inactive-when-rs485-disabled: [ rx-enable-gpios ] > > Signed-off-by: Farouk Bouabid > --- > Documentation/devicetree/bindings/serial/rs485.yaml | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml > index b64577036b5c..4c79dfaaf460 100644 > --- a/Documentation/devicetree/bindings/serial/rs485.yaml > +++ b/Documentation/devicetree/bindings/serial/rs485.yaml > @@ -55,6 +55,11 @@ properties: > description: GPIO to handle a separate RS485 receive enable signal > maxItems: 1 > > + rs485-rx-enable-inactive-when-rs485-disabled: For something a bit shorter, perhaps: rs485-rx-enable-inactive-on-disable > + description: rx-enable GPIO is not active when RS485 is disabled. If missing, active-state > + is assumed. > + $ref: /schemas/types.yaml#/definitions/flag > + > rs485-term-gpios: > description: GPIO pin to enable RS485 bus termination. > maxItems: 1 > > -- > 2.34.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel