From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de ([85.220.165.71]:41205 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbeEDNKY (ORCPT ); Fri, 4 May 2018 09:10:24 -0400 Subject: Re: [PATCH v2 1/3] dt: bindings: i2c-mux-pca954x: add mux-locked property References: <20180504130449.13730-1-bst@pengutronix.de> From: Bastian Stender Message-ID: <43e5cb0f-c76b-186d-6174-73dee92aef8e@pengutronix.de> Date: Fri, 4 May 2018 15:10:22 +0200 MIME-Version: 1.0 In-Reply-To: <20180504130449.13730-1-bst@pengutronix.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org To: Peter Rosin , Wolfram Sang Cc: kernel@pengutronix.de, devicetree@vger.kernel.org, linux-i2c@vger.kernel.org, Michael Lawnick List-ID: On 05/04/2018 03:04 PM, Bastian Stender wrote: > 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. I am not sure about this. I think it will act like the gpmux driver here so I copied it from Documentation/devicetree/bindings/i2c/i2c-mux-gpmux.txt. Is this correct? Regards, Bastian -- Pengutronix e.K. Industrial Linux Solutions http://www.pengutronix.de/ Peiner Str. 6-8, 31137 Hildesheim, Germany Amtsgericht Hildesheim, HRA 2686