Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932909AbcLMK7x (ORCPT ); Tue, 13 Dec 2016 05:59:53 -0500 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:45755 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752746AbcLMK7r (ORCPT ); Tue, 13 Dec 2016 05:59:47 -0500 From: Luis de Oliveira To: Rob Herring , Luis de Oliveira CC: "wsa@the-dreams.de" , "mark.rutland@arm.com" , "jarkko.nikula@linux.intel.com" , "andriy.shevchenko@linux.intel.com" , "mika.westerberg@linux.intel.com" , "linux-i2c@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Ramiro.Oliveira@synopsys.com" , "Joao.Pinto@synopsys.com" , "CARLOS.PALMINHA@synopsys.com" Subject: RE: [PATCH v4 3/5] i2c: designware: Add slave definitions Thread-Topic: [PATCH v4 3/5] i2c: designware: Add slave definitions Thread-Index: AQHSULN7jS4rAW2vqEellbSAnvvnyaEEgM4AgAAl61CAAEJ+AIAAyVuA Date: Tue, 13 Dec 2016 10:50:44 +0000 Message-ID: References: <5173a9456c423025d8f15baafa2499440cbe1b51.1481131072.git.lolivei@synopsys.com> <20161212170214.4cydp256jsp7srar@rob-hp-laptop> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.107.19.94] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id uBDB02An016078 Content-Length: 1955 Lines: 29 The controller for i2c-designware cannot be slave/master at the same time and it has to be enabled knowing beforehand if we want it to be slave or master by something outside of the controller itself. I as looking and I see the use of this I2C_OWN_SLAVE_ADDRESS with the "linux,slave-24c02" slave interface but I am not seeing how it will help me identify a selected i2c-designware block as a "slave" device before instantiation. I'm sorry if I'm not understanding properly. I use the "linux,slave-24c02" to instantiate the i2c-designware as a slave with an address so I can do write/read operations, it is how I tested it. Luis -----Original Message----- From: Rob Herring [mailto:robh@kernel.org] Sent: Monday, December 12, 2016 23:16 To: Luis de Oliveira Cc: wsa@the-dreams.de; mark.rutland@arm.com; jarkko.nikula@linux.intel.com; andriy.shevchenko@linux.intel.com; mika.westerberg@linux.intel.com; linux-i2c@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Ramiro.Oliveira@synopsys.com; Joao.Pinto@synopsys.com; CARLOS.PALMINHA@synopsys.com Subject: Re: [PATCH v4 3/5] i2c: designware: Add slave definitions On Mon, Dec 12, 2016 at 12:35 PM, Luis de Oliveira wrote: > Hi all, Please don't top post. > > The slave address could be set by the I2C slave backend so I can't use it to setup the controller. > A boolean property was my initial approach then Andy and Wolfram Sang suggested the use of compatible strings and later It was suggested to use a property to select mode but I can do it again if it's the best way. > Can you please tell me where should it be documented? bindings/i2c/i2c.txt. Actually, looking at this some more, we already have a way to describe the controller being a slave device with the I2C_OWN_SLAVE_ADDRESS flag in the reg property. We should just need a helper to read reg property of each child and check for the bit set. Rob