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From: Ben Gamari <bgamari.foss-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: beagleboard <beagleboard-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org>,
	linux-omap <linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	David Brownell
	<dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>,
	Eric Miao <eric.miao-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
	Michael Henn
Subject: [RFC PATCH] GPIO chip select support for McSPI
Date: Tue, 21 Dec 2010 12:56:34 -0500	[thread overview]
Message-ID: <1292954195-20204-1-git-send-email-bgamari.foss__28446.0686882541$1292954246$gmane$org@gmail.com> (raw)
In-Reply-To: <1b68c6791001272033q60dd31dbif4de285cd9bac83d-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>


As you may recall, about a year ago I wrote wondering whether it was possible
to use GPIO lines as chip selects in the McSPI driver. A few of you pointed out
that this functionality had been added to other drivers and it should be quite
simple to do the same for McSPI. Two semesters then passed without a followup
from me.

Thankfully, classes are over and I've had some downtime due to sickness,
finally freeing up some time to look at this (just in time as we'll soon need
this functionality). This morning I looked through the relevant code and put
together this patch to add support for GPIO CSs. As was suggested, I modelled
this after the approach taken in the s3c24xx-spi driver. Let me know whether
this looks sane. It has yet to see hardware, but in principle things look
alright (famous last words).

Cheers,

- Ben


P.S. In case people are curious to see an example of usage I have a patch
adding support for multiplexed chip selects to support a data acquisition board
for the BeagleBoard that I've been working on[1]. I can send these out if
people are interested.

[1] http://goldnerlab.physics.umass.edu/wiki/BeagleBoardDaq


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  parent reply	other threads:[~2010-12-21 17:56 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-20 19:47 (no subject) Ben Gamari
2010-01-21  0:04 ` Ben Dooks
2010-01-21  0:04 ` (no subject) Ben Dooks
2010-01-21  0:04 ` Ben Dooks
2010-01-22 15:53 ` Re: Ben Gamari
2010-01-28  4:10 ` McSPI questions pertaining to GPIO chip select support Ben Gamari
     [not found] ` <1264651770-sup-5197@ben-laptop>
2010-01-28  4:15   ` Bill Gatliff
2010-01-28  4:25     ` Ben Gamari
2010-01-28  4:27       ` Bill Gatliff
2010-01-28  4:33   ` jassi brar
     [not found]     ` <1b68c6791001272033q60dd31dbif4de285cd9bac83d-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-01-29  0:32       ` Ben Gamari
2010-01-29  1:09         ` jassi brar
     [not found]           ` <1b68c6791001281709l7d11da30lee486632e85b99cb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-01-29  1:58             ` Ben Gamari
2010-12-21 17:56       ` Ben Gamari [this message]
2010-12-21 17:56       ` [PATCH] mcspi: Add support for GPIO chip select lines Ben Gamari
     [not found]     ` <1292954195-20204-2-git-send-email-bgamari.foss@gmail.com>
2010-12-23 19:59       ` Tony Lindgren
2010-12-23 21:38       ` Grant Likely
2010-12-23 23:09         ` Ben Gamari
2010-12-24  0:37           ` Grant Likely
2010-12-24  2:27             ` Ben Gamari
2010-12-24  3:28               ` Grant Likely
2010-12-24  6:05                 ` Ben Gamari
2011-02-12  8:33                   ` Grant Likely
2011-02-13 22:07                     ` Ben Gamari
2011-08-30 10:14   ` McSPI questions pertaining to GPIO chip select support Raju Sana
2011-08-30 13:50     ` Ben Gamari
2011-08-30 13:50       ` [PATCH] mcspi: Add support for GPIO chip select lines Ben Gamari
2011-08-30 13:52       ` [PATCH] beagledaq: Hack in cs_gpios Ben Gamari
     [not found]         ` <1314712343-27367-1-git-send-email-bgamari.foss-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2011-09-05 12:42           ` Raju Sana

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