From owner-freebsd-arm@FreeBSD.ORG  Thu Jun  7 08:07:04 2007
Return-Path: <owner-freebsd-arm@FreeBSD.ORG>
X-Original-To: arm@freebsd.org
Delivered-To: freebsd-arm@FreeBSD.ORG
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 38B4C16A476
	for <arm@freebsd.org>; Thu,  7 Jun 2007 08:07:04 +0000 (UTC)
	(envelope-from bkoenig@alpha-tierchen.de)
Received: from mail.liberty-hosting.de (mail.smartterra.de [195.225.132.203])
	by mx1.freebsd.org (Postfix) with ESMTP id E866613C48C
	for <arm@freebsd.org>; Thu,  7 Jun 2007 08:07:01 +0000 (UTC)
	(envelope-from bkoenig@alpha-tierchen.de)
Received: from mail.liberty-hosting.de ([195.225.132.203])
	by localhost (liberty-mail [195.225.132.203]) (amavisd-new, port 10024)
	with ESMTP id 30176-03; Thu,  7 Jun 2007 10:06:58 +0200 (CEST)
Received: from home.alpha-tierchen.de (port-212-202-170-5.dynamic.qsc.de
	[212.202.170.5])
	by mail.liberty-hosting.de (Postfix) with ESMTP id 2F55817F05D;
	Thu,  7 Jun 2007 10:06:58 +0200 (CEST)
Received: from webmail.alpha-tierchen.de (localhost [127.0.0.1])
	by home.alpha-tierchen.de (Postfix) with ESMTP id 01D9845046;
	Thu,  7 Jun 2007 10:06:57 +0200 (CEST)
Received: from 2001:6f8:101e:0:20e:cff:fe6d:6adb
	(SquirrelMail authenticated user bkoenig)
	by webmail.alpha-tierchen.de with HTTP;
	Thu, 7 Jun 2007 10:06:57 +0200 (CEST)
Message-ID: <53054.2001:6f8:101e:0:20e:cff:fe6d:6adb.1181203617.squirrel@webmail.alpha-tierchen.de>
In-Reply-To: <20070607005128.T43808@synthcom.com>
References: <50503.2001:6f8:101e:0:20e:cff:fe6d:6adb.1181202550.squirrel@webmail.alpha-tierchen.de>
	<20070607005128.T43808@synthcom.com>
Date: Thu, 7 Jun 2007 10:06:57 +0200 (CEST)
From: =?iso-8859-1?Q?Bj=F6rn_K=F6nig?= <bkoenig@alpha-tierchen.de>
To: "Neil Bradley" <nb@synthcom.com>
User-Agent: SquirrelMail/1.4.10a
MIME-Version: 1.0
Content-Type: text/plain;charset=iso-8859-1
Content-Transfer-Encoding: 8bit
X-Priority: 3 (Normal)
Importance: Normal
X-Virus-Scanned: by amavisd-new at mail.smartterra.de
Cc: arm@freebsd.org
Subject: Re: 4-bit SD Card mode
X-BeenThere: freebsd-arm@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Porting FreeBSD to the StrongARM Processor <freebsd-arm.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arm>,
	<mailto:freebsd-arm-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arm>
List-Post: <mailto:freebsd-arm@freebsd.org>
List-Help: <mailto:freebsd-arm-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arm>,
	<mailto:freebsd-arm-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Jun 2007 08:07:04 -0000

Neil wrote:
> I've done SD drivers, both 1 and 4 bit, DMA and programmed I/O, on the
> PXA270, Atmel SAM7, Atmel SAM9, and Freescale MX31 CPUs. How may I be of
> assistance?

Actually the driver does the whole status and error handling using an
interrupt service routine. This is unsuitable in 4-bit mode because in
this mode the interrupt line is shared with a data line. So to get 4-bit
mode working it is necessary to know the complete definition of the
"interrupt period" - the period where it is allowed to enable the
interrupt during 4-bit mode.

Björn