Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262235AbVDFPqv (ORCPT ); Wed, 6 Apr 2005 11:46:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262233AbVDFPqu (ORCPT ); Wed, 6 Apr 2005 11:46:50 -0400 Received: from smtp-send.myrealbox.com ([192.108.102.143]:16105 "EHLO smtp-send.myrealbox.com") by vger.kernel.org with ESMTP id S262231AbVDFPqd convert rfc822-to-8bit (ORCPT ); Wed, 6 Apr 2005 11:46:33 -0400 Subject: Re: HELP:(VIPER BOARD)AC'97 controller driver for rtlinux(rtlinux core driver) From: "nitin ahuja" To: nobin_matthew@yahoo.com CC: kernelnewbies@nl.linux.org, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org, linux-arm-kernel@lists.arm.linux.org.uk Date: Wed, 06 Apr 2005 09:46:16 -0600 X-Mailer: NetMail ModWeb Module MIME-Version: 1.0 Message-ID: <1112802376.8c7c3afcnitin2ahuja@myrealbox.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1078 Lines: 31 Hi, > > I am trying to develop a codec driver (rtlinux > driver) from scratch. In Viper board (PXA255) > physical memory range 0x40000000-0x43FFFFFF is used > by the PXA255 peripherals.In that address range > 0x40500000-0x405005FC is needed for AC'97 controller > registers. Is this memory range is already mapped to > virtual address space, else How to map this to > virtual address space. > You have to map this address range using "ioremap()". Data at address returned by ioremap can be accessed by calling readl(), writel() et al > > When i tried ioremap() it is giving same virtual > address with different physical address(i tried > ioremap with another driver(same board)with different > physical memory address) > Same virtual address can point to different physical addresses depending upon how it is mapped. Nitin - 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/