From owner-freebsd-embedded@FreeBSD.ORG  Sun Dec  4 17:21:53 2011
Return-Path: <owner-freebsd-embedded@FreeBSD.ORG>
Delivered-To: freebsd-embedded@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 5A300106566C
	for <freebsd-embedded@FreeBSD.org>;
	Sun,  4 Dec 2011 17:21:53 +0000 (UTC) (envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85])
	by mx1.freebsd.org (Postfix) with ESMTP id 117B38FC17
	for <freebsd-embedded@FreeBSD.org>;
	Sun,  4 Dec 2011 17:21:52 +0000 (UTC)
Received: from [10.0.0.150] (150.imp.bsdimp.com [10.0.0.150] (may be forged))
	(authenticated bits=0)
	by harmony.bsdimp.com (8.14.4/8.14.3) with ESMTP id pB4HJtEs032243
	(version=TLSv1/SSLv3 cipher=DHE-DSS-AES128-SHA bits=128 verify=NO);
	Sun, 4 Dec 2011 10:19:58 -0700 (MST) (envelope-from imp@bsdimp.com)
Mime-Version: 1.0 (Apple Message framework v1084)
Content-Type: text/plain; charset=us-ascii
From: Warner Losh <imp@bsdimp.com>
In-Reply-To: <A78C6CC2-A6C9-42CC-B128-871C34C201CD@lassitu.de>
Date: Sun, 4 Dec 2011 10:19:53 -0700
Content-Transfer-Encoding: quoted-printable
Message-Id: <2B6F6CAC-F4EF-4958-A435-579A69862AE5@bsdimp.com>
References: <A78C6CC2-A6C9-42CC-B128-871C34C201CD@lassitu.de>
To: Stefan Bethke <stb@lassitu.de>
X-Mailer: Apple Mail (2.1084)
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1
	(harmony.bsdimp.com [10.0.0.6]);
	Sun, 04 Dec 2011 10:19:58 -0700 (MST)
Cc: freebsd-embedded@FreeBSD.org
Subject: Re: ar71xx_gpio.c touches SPI_CS1 and 2?
X-BeenThere: freebsd-embedded@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Dedicated and Embedded Systems <freebsd-embedded.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-embedded>, 
	<mailto:freebsd-embedded-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-embedded>
List-Post: <mailto:freebsd-embedded@freebsd.org>
List-Help: <mailto:freebsd-embedded-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-embedded>, 
	<mailto:freebsd-embedded-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 04 Dec 2011 17:21:53 -0000


On Dec 4, 2011, at 5:14 AM, Stefan Bethke wrote:

> I was looking into why I can't manipulate the USB led on my =
TL-WR1043ND, and came across the SPI chip selects, which share GPIO 0 =
and 1, respectively.  The USB led is hooked up to GPIO 1.
>=20
> sys/mips/atheros/ar71xx_gpio.c:ar71xx_gpio_attach(device_t dev) =
enables both chip selects, and detach disables them again.
>=20
> Two points:
>=20
> - how can we express different uses for those two pins on a per-board =
config?
>=20
> - disabling the function is not correct for the gpio driver, I would =
think.  If you load and unload it as a module, I expect losing access to =
the flash.

When I was looking into this question for the Atmel chips, I was torn.  =
On the one hand, it would be nice if there was a pin mux device.  On the =
other hand, it didn't map well into the device model.  I finally settled =
on having per-board functions that setup the pins.  This is also the =
model followed by linux.  Either the boot loader or the board-dependent =
code would do the setup.

Warner