From patchwork Fri May 4 13:04:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bastian Krause X-Patchwork-Id: 908701 X-Patchwork-Delegate: patchwork@peda.user.lysator.liu.se Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40csh30cV9z9s3Z for ; Fri, 4 May 2018 23:05:39 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751107AbeEDNFg (ORCPT ); Fri, 4 May 2018 09:05:36 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:55569 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbeEDNFf (ORCPT ); Fri, 4 May 2018 09:05:35 -0400 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1fEaOz-00010G-TV; Fri, 04 May 2018 15:05:33 +0200 From: Bastian Stender To: Peter Rosin , Wolfram Sang Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, Michael Lawnick , kernel@pengutronix.de, Bastian Stender Subject: [PATCH v2 1/3] dt: bindings: i2c-mux-pca954x: add mux-locked property Date: Fri, 4 May 2018 15:04:47 +0200 Message-Id: <20180504130449.13730-1-bst@pengutronix.de> X-Mailer: git-send-email 2.17.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: bst@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-i2c@vger.kernel.org Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Signed-off-by: Bastian Stender --- .../devicetree/bindings/i2c/i2c-mux-pca954x.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt index 34d91501342e..864ac91f8c1c 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt @@ -36,6 +36,22 @@ Optional Properties: - first cell is the pin number - second cell is used to specify flags. See also Documentation/devicetree/bindings/interrupt-controller/interrupts.txt + - mux-locked: If present, explicitly allow unrelated I2C transactions on the + parent I2C adapter at these times: + + during setup of the multiplexer + + between setup of the multiplexer and the child bus I2C transaction + + between the child bus I2C transaction and releasing of the multiplexer + + during releasing of the multiplexer + + However, I2C transactions to devices behind all I2C multiplexers connected + to the same parent adapter that this multiplexer is connected to are blocked + for the full duration of the complete multiplexed I2C transaction (i.e. + including the times covered by the above list). + If mux-locked is not present, the multiplexer is assumed to be parent-locked. + This means that no unrelated I2C transactions are allowed on the parent I2C + adapter for the complete multiplexed I2C transaction. + The properties of mux-locked and parent-locked multiplexers are discussed + in more detail in Documentation/i2c/i2c-topology. Example: