Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759213Ab1CaVsS (ORCPT ); Thu, 31 Mar 2011 17:48:18 -0400 Received: from host171.canaca.com ([67.55.55.225]:51788 "EHLO host171.canaca.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753538Ab1CaVsR (ORCPT ); Thu, 31 Mar 2011 17:48:17 -0400 Message-ID: Date: Thu, 31 Mar 2011 17:48:13 -0400 Subject: Poulsbo I2C - /dev/i2c not seen when loading i2c-dev From: simon@mungewell.org To: linux-input@vger.kernel.org Cc: "Jacob Pan" , linux-kernel@vger.kernel.org User-Agent: SquirrelMail/1.4.20 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - host171.canaca.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - mungewell.org X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 46 Hi all, I'm hoping that someone here can help. I am trying to get userland access to the I2C bus(es) on an embedded system, however recent kernels (ie. 2.6.38) are not 'loading' any buses when I 'modprobe i2c-dev'. Going back to ?2.6.32? I am able to see 1 bus, and 'i2cdetect 0' shows a single device sitting at address 0x69 (which I believe to EEPROM on the wifi card... not confirmed). The board is built around the Poulsbo and therefore using the 'i2c-isch' driver. Reviewing the schematic I see that there are several buses, each going to individual components: IT8516 U5/110+111 -> LTC1760 U6/18+22 [battery charger ? 0x1A/0x12] IT8516 U5/115+116 -> W83L771 U60/8+7 [thermal sensor ? 0x18??] IT8516 U5/117+118 -> LSM303DLH U64/19+20 [accel/compass ? 0x19] POULSBO U2/G37+H38 -> PCI Express Socket I am a little dismayed by the comment in 'i2c-isch.c' which suggest it can handle only one i2c bus at any time. -- /* Supports: Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L) Note: we assume there can only be one device, with one SMBus interface. */ -- This seems to correlate to these comments: http://www.linuxforums.org/forum/programming-scripting/175147-smbus-intel-sch-us15w.html Can anyone confirm whether this is actually the case, and whether it is possible to configure it to use a different controller address. One would expect this to be a module option I guess, however it doesn't seem to take any. Many thanks in advance, Simon. -- 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/