Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751932AbaKZMrf (ORCPT ); Wed, 26 Nov 2014 07:47:35 -0500 Received: from sauhun.de ([89.238.76.85]:41623 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbaKZMrd (ORCPT ); Wed, 26 Nov 2014 07:47:33 -0500 Date: Wed, 26 Nov 2014 13:49:01 +0100 From: Wolfram Sang To: Alexander Kochetkov Cc: Stijn Devriendt , linux-i2c@vger.kernel.org, linux-sh@vger.kernel.org, Magnus Damm , Simon Horman , Laurent Pinchart , Geert Uytterhoeven , LKML , linux-arm-kernel@lists.infradead.org, Jean Delvare Subject: Re: [PATCH 2/3] i2c: slave-eeprom: add eeprom simulator driver Message-ID: <20141126124901.GB4397@katana> References: <1416326695-13083-1-git-send-email-wsa@the-dreams.de> <1416326695-13083-3-git-send-email-wsa@the-dreams.de> <20141122181229.GB9698@katana> <2A7C987F-15E0-46FD-A711-E7F5BA9893FC@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="TakKZr9L6Hm6aLOc" Content-Disposition: inline In-Reply-To: <2A7C987F-15E0-46FD-A711-E7F5BA9893FC@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --TakKZr9L6Hm6aLOc Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 26, 2014 at 03:25:29PM +0300, Alexander Kochetkov wrote: >=20 > 22 =D0=BD=D0=BE=D1=8F=D0=B1. 2014 =D0=B3., =D0=B2 21:12, Wolfram Sang =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB(=D0=B0): >=20 > > IMO a repeated start is to ensure that two messages arrive at the slave > > without interruption from another master. I can't think why a slave > > should know which type of start that was. In fact, if it does that would > > raise an eyebrow for me. Do you have an example? >=20 > It is used to implement Device ID reading. Yes and no, I'd say :) Technically, it needs repeated start. But really, the hardware should handle this (and I know one IP core which has support for it). One could try to simulate the behaviour in the bus driver IF a second slave address AND detection of repeated start is available, but I doubt this combination exists. Still, all the _slave driver_ needs to handle is an I2C_SLAVE_EVENT_DEVICE_ID which should return the apropriate value. That being said, I have never seen querying Device ID in action. > Not sure, that the feature is really needed for the first release. I am sure it is not :D Thanks, Wolfram --TakKZr9L6Hm6aLOc Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUdcw9AAoJEBQN5MwUoCm2qxoQAIl08hAkuy5kOMxeI4dU/Q6y hi1BQhXGh0dkdmFYChU5czJKLlN0OJNLxSJOE5RWV4w1n4XxoOTQn8i9uDhRrj3F yfYe7achb8kPbRUl//VeV1oo9isAY7hEbCe0V0vNlsjoxKac8/Xceg1Fs0qA4vOE hoQA+cZsXvJtfzj4axmMFOYpwUtoVomF1XF6OgrV/Bs0d595w28CwGeeiWQvn1Bo daY2adI7VwfPt3xu39YdjFlOdyfmZY4s7UmjDu63nF5lgwmDTPBnJSXsKhvYa61Q +CLZORfua/0HhUKGH+NFMIhgg5+2XnqWW7z+tW+n7oNX05oMmmEWuFLZWdWjHJua atMLHRjIeMXXxeD+JC9F/aDnw5TnvnNSFbm737QbZ2rJLvEr/0P2YIkL8h7W9ejk iTFpbqPQGEONowq3+kSYIcb22YPaPyG5U0K+DdRfX46LJahAkiey7Cq4eOi9WbjD fZgDDvIQUT55LrpBjrf0RfhkqZlL64C2wmlUFP6Ia8NIM3rnq1R6ZKicpToNmlRu NdLfV+YRL4fIwgLs6i4oLtGc/rWTDqFz7T1PbF6RVXpXddNL3R3AoWqQI6ZYx8+7 s8sIbO2cytAnJRZu7hYptJIF99QY1zdiJRLKP76YxKKq72syfN/XO/IUUtXCnX4L zuCs7DtbhsO1MpDbZWVd =DsTe -----END PGP SIGNATURE----- --TakKZr9L6Hm6aLOc-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/