From: Segher Boessenkool <segher-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
To: Guennadi Liakhovetski <g.liakhovetski-Mmb7MZpHnFY@public.gmane.org>
Cc: fabrizio.garetto-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org,
dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH 3/4] spi: Add OF binding support for SPI busses
Date: Wed, 21 May 2008 21:11:42 +0200 [thread overview]
Message-ID: <716a0f1b6c9a544b480c06a329072483@kernel.crashing.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0805201650280.5283-0199iw4Nj15frtckUFj5Ag@public.gmane.org>
> Ok, elegance apart:-) You can use the SPI-bridge construct to also
> describe simple SPI-chipselect configurations. But is it really a good
> idea? Wouldn't it be better to handle these two cases separately?
It would be best to handle all these things that are specific to
a certain SPI controller (like how CSs work) in the binding for
that SPI controller, and not try to shoehorn all of this into some
artificial generic framework.
If you can have identical addresses on the SPI bus going to different
devices based on which CS is asserted, you'll have to make the CS part
of the "reg". Example:
spi-controller {
#address-cells = 2;
#size-cells = 0;
some-device@0,f000 { reg = < 0 f000 >; } // CS 0, SPI address f000
some-device@1,f000 { reg = < 1 f000 >; } // CS 1, SPI address f000
some-device@1,ff00 { reg = < 1 ff00 >; } // CS 1, SPI address ff00
}
SPI-to-SPI bridges can (and should!) be handled the same way as
anything-to-anything-else bridges are handled as well: either there
is a nice simple one-to-one matching (and you can use "ranges") or
you need a driver for that bridge that knows how to make it work (or
both, "ranges" isn't always enough, the bridge might require some
specific handling for some special situations -- error handling,
suspend, whatever).
Segher
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next prev parent reply other threads:[~2008-05-21 19:11 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-16 19:35 [RFC PATCH 0/4] Describe SPI devices in the OF device tree and add mpc5200-spi driver Grant Likely
2008-05-16 19:36 ` [PATCH 1/4] spi: Change modalias from a pointer to a character array Grant Likely
2008-05-16 19:36 ` [PATCH 2/4] spi: split up spi_new_device() to allow two stage registration Grant Likely
[not found] ` <20080516193608.28030.34968.stgit-8FIgwK2HfyId2tlXD8uQ6/kpB+XfMlBf@public.gmane.org>
2008-05-22 0:17 ` David Brownell
[not found] ` <200805211717.13206.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 6:43 ` Grant Likely
[not found] ` <fa686aa40805232343x20031560j5659d203e25f494-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 6:54 ` Grant Likely
[not found] ` <fa686aa40805232354g147acfcdx4753fce1a448ceb7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-06-30 4:08 ` David Brownell
2008-06-17 7:28 ` Grant Likely
[not found] ` <fa686aa40806170028t2ccb679k22d2d3cea793ebc1-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-06-30 4:10 ` David Brownell
2008-05-16 19:36 ` [PATCH 3/4] spi: Add OF binding support for SPI busses Grant Likely
[not found] ` <20080516193613.28030.13950.stgit-8FIgwK2HfyId2tlXD8uQ6/kpB+XfMlBf@public.gmane.org>
2008-05-16 20:47 ` Randy Dunlap
2008-05-16 20:51 ` Grant Likely
2008-05-16 22:03 ` Anton Vorontsov
2008-05-16 22:14 ` Grant Likely
[not found] ` <fa686aa40805161514r513d0eebt380a76f64abe8434-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-16 22:49 ` Anton Vorontsov
2008-05-17 5:02 ` Grant Likely
[not found] ` <fa686aa40805162202m336aade4qd6cfa5b17d6f3892-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-22 1:16 ` David Brownell
[not found] ` <200805211816.10753.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 6:24 ` Grant Likely
2008-05-19 13:17 ` Guennadi Liakhovetski
2008-05-19 15:57 ` Grant Likely
2008-05-19 16:30 ` Guennadi Liakhovetski
[not found] ` <Pine.LNX.4.64.0805191811510.29559-0199iw4Nj15frtckUFj5Ag@public.gmane.org>
2008-05-20 5:13 ` Grant Likely
2008-05-20 15:26 ` Guennadi Liakhovetski
[not found] ` <Pine.LNX.4.64.0805201650280.5283-0199iw4Nj15frtckUFj5Ag@public.gmane.org>
2008-05-20 15:48 ` Grant Likely
2008-05-21 19:11 ` Segher Boessenkool [this message]
[not found] ` <716a0f1b6c9a544b480c06a329072483-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2008-05-21 19:33 ` Grant Likely
[not found] ` <fa686aa40805211233h72a258bpf8c945b9f662d6ee-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-23 2:26 ` David Brownell
[not found] ` <200805221926.24112.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 6:25 ` Grant Likely
[not found] ` <fa686aa40805232325w65d4f706i50798121a8cce263-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 7:13 ` David Brownell
2008-05-19 17:09 ` Gary Jennejohn
[not found] ` <20080519190900.01ec3b2a-f7AvneZ2CE0iXleZOAq1AWD2FQJk+8+b@public.gmane.org>
2008-05-19 17:19 ` Anton Vorontsov
2008-05-21 15:19 ` Anton Vorontsov
[not found] ` <20080521151928.GA28857-PHTr8nzUCjejyJ0x5qLZdcN33GVbZNy3@public.gmane.org>
2008-05-23 2:05 ` David Brownell
[not found] ` <200805221905.32288.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 6:26 ` Grant Likely
[not found] ` <fa686aa40805232326w35f455d1s274899160d47eccb-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 16:50 ` Grant Likely
[not found] ` <fa686aa40805240950ocd16b97y308a54c68efa28ef-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 17:14 ` Jochen Friedrich
[not found] ` <48384D13.6010608-NIgtFMG+Po8@public.gmane.org>
2008-05-24 17:33 ` Grant Likely
[not found] ` <fa686aa40805241033x128c30b0v826717cc879a712e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 17:45 ` David Brownell
[not found] ` <200805241045.47448.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-25 4:56 ` Grant Likely
2008-05-24 17:43 ` David Brownell
[not found] ` <200805221915.59878.david-b@pacbell.net>
[not found] ` <200805221915.59878.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 6:31 ` Grant Likely
[not found] ` <fa686aa40805232331p1bf2c1bcn8c46c21a094ef01e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-24 16:50 ` David Brownell
[not found] ` <200805240950.43394.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-24 16:53 ` Grant Likely
2008-05-16 19:36 ` [PATCH 4/4] [CSB] Add new mpc5200-spi (non-psc) device driver Grant Likely
2008-05-16 19:42 ` Grant Likely
[not found] ` <20080516193054.28030.35126.stgit-8FIgwK2HfyId2tlXD8uQ6/kpB+XfMlBf@public.gmane.org>
2008-05-16 20:27 ` [RFC PATCH 0/4] Describe SPI devices in the OF device tree and add mpc5200-spi driver Jon Smirl
[not found] ` <9e4733910805161327u4c42fd1dg5b09319d89db447c-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-16 20:48 ` Grant Likely
[not found] ` <fa686aa40805161348t52b94956w112ef6926ff30892-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-16 21:25 ` Jon Smirl
[not found] ` <9e4733910805161425i2d6cc034y3377af053a4198b5-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-16 21:32 ` Grant Likely
[not found] ` <fa686aa40805161432w6b5243f9nb0d0c32a87d86d02-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-16 21:42 ` Jon Smirl
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