From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de ([85.220.165.71]:46159 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbeEDNFg (ORCPT ); Fri, 4 May 2018 09:05:36 -0400 From: 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> Sender: devicetree-owner@vger.kernel.org To: Peter Rosin , Wolfram Sang Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, Michael Lawnick , kernel@pengutronix.de, Bastian Stender List-ID: 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: -- 2.17.0