From: broonie@opensource.wolfsonmicro.com (Mark Brown)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 10/10] spi: s3c64xx: add device tree support
Date: Wed, 9 May 2012 15:32:00 +0100 [thread overview]
Message-ID: <20120509143159.GU3955@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <CAJuYYwQF9Hh3wJpPTfXm_5iirvHzgwDu6imuSgH-ggenj=Vc8Q@mail.gmail.com>
On Wed, May 09, 2012 at 10:13:28PM +0800, Thomas Abraham wrote:
> On 9 May 2012 17:07, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote:
> > On Wed, May 09, 2012 at 03:34:54AM +0530, Thomas Abraham wrote:
> >> +- gpios: The gpio specifier for clock, mosi and miso interface lines (in no
> >> + ?particular order). The format of the gpio specifier depends on the gpio
> >> + ?controller.
> > This seems odd... ?This isn't a bitbanging controller, and surely the
> > driver will need to know which signal is which? ?I suspect this is
> > actually for pinmux rather than to identify the signals but that should
> > at least be made clear and really should be being done using the pinmux
> > API.
> The driver retrieves the list of gpio's that it is allowed to use. The
> gpio numbers for miso, mosi and clk are mandatory but the order in
> which they are specified is not important since the driver never needs
> to which gpio is which interface line. I agree the pinmux api should
> be used here, but the call to pinmux api would be a incremental change
> here, not changing the code this patch is adding.
I'd suggest just specifying the order - someone might want to use it
later for some reason and it's not really a hardship for someone to use
it. Avoids any "how does that work?" questions like I had.
> >> + ?- samsung,spi-cs-gpio: A gpio specifier that specifies the gpio line used as
> >> + ? ?the slave select line by the spi controller. The format of the gpio
> >> + ? ?specifier depends on the gpio controller.
> > We should really have a binding for this at the SPI level (and ideally
> > some code to manage setting the GPIO too) - it's pretty common to use a
> > GPIO as /CS.
> The existing implementations vary in the way the nCS gpio lines are
> specified. For some controllers, the nCS gpio's are included in the
> spi device node whereas in this implementation, the nCS gpio is listed
> in the spi slave device node.
Yeah, I know. I'm saying we should try to come up with a binding for
this that can be used by new SPI contollers going forward so things are
consistent.
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next prev parent reply other threads:[~2012-05-09 14:32 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-08 22:04 [PATCH 00/10] spi: s3c64xx: add support for device tree Thomas Abraham
2012-05-08 22:04 ` [PATCH 01/10] spi: s3c64xx: remove unused S3C64XX_SPI_ST_TRLCNTZ macro Thomas Abraham
2012-05-20 4:41 ` Grant Likely
2012-05-08 22:04 ` [PATCH 02/10] spi: s3c64xx: move controller information into driver data Thomas Abraham
2012-05-20 4:42 ` Grant Likely
2012-05-30 7:23 ` Olof Johansson
2012-05-30 8:00 ` Thomas Abraham
2012-05-08 22:04 ` [PATCH 03/10] ARM: Samsung: Remove spi hardware controller information from platform data Thomas Abraham
2012-05-08 22:04 ` [PATCH 04/10] ARM: Samsung: Remove pdev pointer paremeter from spi gpio setup functions Thomas Abraham
2012-05-08 22:04 ` [PATCH 05/10] ARM: Samsung: Update the device names for spi clock lookup Thomas Abraham
2012-05-09 8:52 ` Mark Brown
2012-05-09 13:40 ` Thomas Abraham
2012-05-09 14:28 ` Mark Brown
2012-05-09 17:17 ` Thomas Abraham
2012-05-13 14:51 ` Mark Brown
2012-05-20 4:43 ` Grant Likely
2012-05-08 22:04 ` [PATCH 06/10] ARM: Samsung: Modify s3c64xx_spi{0|1|2}_set_platdata function Thomas Abraham
2012-05-09 8:56 ` Mark Brown
2012-05-09 9:10 ` Heiko Stübner
2012-05-09 10:55 ` Mark Brown
2012-05-09 14:22 ` Thomas Abraham
2012-05-09 14:33 ` Mark Brown
2012-05-09 15:06 ` Thomas Abraham
2012-05-08 22:04 ` [PATCH 07/10] spi: s3c64xx: Remove the 'set_level' callback from controller data Thomas Abraham
2012-05-09 8:03 ` Jassi Brar
2012-05-09 9:20 ` Heiko Stübner
2012-05-09 10:31 ` Jassi Brar
2012-05-20 4:45 ` Grant Likely
2012-05-08 22:04 ` [PATCH 08/10] ARM: Exynos4: Fix the incorrect hierarchy of spi controller bus clock Thomas Abraham
2012-05-08 22:04 ` [PATCH 09/10] ARM: Exynos5: Add spi clock support Thomas Abraham
2012-05-08 22:04 ` [PATCH 10/10] spi: s3c64xx: add device tree support Thomas Abraham
2012-05-09 9:07 ` Mark Brown
2012-05-09 14:13 ` Thomas Abraham
2012-05-09 14:32 ` Mark Brown [this message]
2012-05-09 16:39 ` Thomas Abraham
2012-05-09 16:47 ` Mark Brown
2012-05-09 17:19 ` Thomas Abraham
2012-05-09 8:17 ` [PATCH 00/10] spi: s3c64xx: add support for device tree Jassi Brar
2012-05-22 12:35 ` padma venkat
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