From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6FFCC3A59E for ; Mon, 2 Sep 2019 21:32:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 989FE21881 for ; Mon, 2 Sep 2019 21:32:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbfIBVcR (ORCPT ); Mon, 2 Sep 2019 17:32:17 -0400 Received: from sauhun.de ([88.99.104.3]:44486 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726964AbfIBVcR (ORCPT ); Mon, 2 Sep 2019 17:32:17 -0400 Received: from localhost (p54B337C1.dip0.t-ipconnect.de [84.179.55.193]) by pokefinder.org (Postfix) with ESMTPSA id BDB4F2C0165; Mon, 2 Sep 2019 23:32:15 +0200 (CEST) Date: Mon, 2 Sep 2019 23:32:15 +0200 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-media@vger.kernel.org Subject: BoF at LPC "New hardware with modern I2C address conflicts" Message-ID: <20190902213215.GD7253@kunai> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="/3yNEOqWowh/8j+e" Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org --/3yNEOqWowh/8j+e Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hey everyone, at LPC next week in Lisboa, there will be a BoF run by me which I want to point out. Quoting the official description[1]: === "New hardware with modern I2C address conflicts" For some time now, special camera setups exist having features which are challenging for I2C address layouts as we know them in Linux: a) a high-speed serial link which can embed I2C communication (e.g. GMSL or FPD-Link III) and b) the ability to reprogram the client addresses of the I2C devices on the camera. The use case for these cameras is to run multiple of them in parallel, and not just a single one. To be easily pluggable, they don't have a way to configure the I2C addresses they need. They use initially all the same I2C addresses and rely on software to reprogram them and sort out that problem. The really tricky thing is now that they are connected to the same serial high speed link. As a result, all the clients with initially equal addresses sit (more or less, depending on the link) on the same I2C bus as well and need to be carefully reprogrammed one-by-one to a unique address. The camera setup above is the primary example we are facing right now. Some early implementations for GMSL and FPD-Link exist with different approaches to map the I2C topology. However, there might be other hardware facing very similar problems. We definitely want to have you in the room. An introductory talk gives a few more details of current implementations, and explains the current problems in abstracting all this. From there on, we hope to have gathered enough highly interested people for discussion, opinions, and brainstorming. The goal is, of course, to enhance the I2C core to provide reasonable support for such scenarios which will be beneficial for all users like these high speed links. ==== The BoF takes place 11 Sep 2019, 10:45 in the Ametista-room-I. If you face similar problems, know other HW behaving like this, or are simply interested, you are very welcome to join the BoF. Or contact me beforehand at the conference. Hope to see you there! Happy hacking, Wolfram [1] https://linuxplumbersconf.org/event/4/contributions/542/ --/3yNEOqWowh/8j+e Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl1tilsACgkQFA3kzBSg KbZYkA//dVIarSguujsqS8z9aAMXc+bxSGjUXfDHKTqOl4iNvncXrMGGKtpB16Kh oBd/YPDgzcjPjUcVGSoauR6Xyy29DgHD+8JgRh5cvAPO2HDH+Nesi1KFNOk3yLKd NZuYD+5YWwxYMePXgwjnMImPRkxuSzZtuzpuTCrKP02z/Kv0eeAQZoFAp2+JXWeR YkXqQsP7JNJlzATT8T6nSmq2CuYTL1UUvISd+0DK//7qZXtC1SR+Cgtl0WwmcfHi LlEQy03+Q+oS3SWvksObwxN4gF+KhwU1wyWyzAJ5G0nXk4RyfWarCneGLx5Vpeaq VJBf3RwbK3TL4LUlS2RzR1KTc2OMdu7L2aCHzx1Zq2HWlPvaZolxjly8hqCs249v 6m79KS5lFDbV6ZEqi+ic/bmwh9YvmEtBPMispHVnbezv+t3pKe9pNfLvSHHKCF6o r6qpHujt3EhhNX3/wxFwWjHFz5b/TR7txvqgHCMPoon04o9GoMuL9F8JL7XkBx6C /FrOcpAQUGT8aKBNGY3XPMHeBa75UMPHFo6nAsdlLyWbdtcRSjEOua8N1jY5uPip 7n7rKNnwVXThXLD6101ab+Z8U3ZFgW2Uu2xT/uyKZ4RJwr9k0tRc1oES9FVYWBtX iCaams5HSoNeSo70i4pSQ0Y2wphxfJCfWGfJFQex2EpeRdfhfGM= =fCdU -----END PGP SIGNATURE----- --/3yNEOqWowh/8j+e--