All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: spi-devel-general@lists.sourceforge.net,
	Shawn Guo <shawn.guo@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	Brian Lilly <brian@crystalfontz.com>
Subject: Re: [PATCH 1/2] spi: spidev: Add device tree bindings
Date: Mon, 29 Oct 2012 16:10:24 +0000	[thread overview]
Message-ID: <20121029161023.GC4511@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <508EA013.7050907@free-electrons.com>


[-- Attachment #1.1: Type: text/plain, Size: 1403 bytes --]

On Mon, Oct 29, 2012 at 04:26:11PM +0100, Maxime Ripard wrote:

> Ok, so I guess that leaves us with 2 choices here:

>   * Declare the device in the dt as you would have with any other
>     driver, with its own compatible string, and we add this compatible
>     string to the spidev dt ids array. It allows to use the existing
>     code and thus doesn't require any effort at all, but it will
>     generate a lot of noise for the spidev driver, since all of us will
>     need to add its compatible string to spidev.

>   * Rework the spidev code so that it behaves mostly like i2c-dev, that
>     is you have an instance of it for every device enumerated in the dt,
>     regardless of wether it has a driver loaded or not. If the
>     userspace opens the device file corresponding to a device already
>     attached to a driver, you return EBUSY, and that's it. I guess it
>     would be the cleaner solution, since you only select spidev in
>     configuration, but it definitely requires way more development than
>     the first one.

> What's your views on this?
> Did you have in mind another solution?

I think either solution is good, obviously Grant's more the expert here.
Adding the IDs is obviously simpler and doesn't preclude later doing the
i2c-dev style thing so short term I'd probably add the IDs to get things
going and punt on the difficult stuff for the time being but YMMV.

[-- Attachment #1.2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: broonie@opensource.wolfsonmicro.com (Mark Brown)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] spi: spidev: Add device tree bindings
Date: Mon, 29 Oct 2012 16:10:24 +0000	[thread overview]
Message-ID: <20121029161023.GC4511@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <508EA013.7050907@free-electrons.com>

On Mon, Oct 29, 2012 at 04:26:11PM +0100, Maxime Ripard wrote:

> Ok, so I guess that leaves us with 2 choices here:

>   * Declare the device in the dt as you would have with any other
>     driver, with its own compatible string, and we add this compatible
>     string to the spidev dt ids array. It allows to use the existing
>     code and thus doesn't require any effort at all, but it will
>     generate a lot of noise for the spidev driver, since all of us will
>     need to add its compatible string to spidev.

>   * Rework the spidev code so that it behaves mostly like i2c-dev, that
>     is you have an instance of it for every device enumerated in the dt,
>     regardless of wether it has a driver loaded or not. If the
>     userspace opens the device file corresponding to a device already
>     attached to a driver, you return EBUSY, and that's it. I guess it
>     would be the cleaner solution, since you only select spidev in
>     configuration, but it definitely requires way more development than
>     the first one.

> What's your views on this?
> Did you have in mind another solution?

I think either solution is good, obviously Grant's more the expert here.
Adding the IDs is obviously simpler and doesn't preclude later doing the
i2c-dev style thing so short term I'd probably add the IDs to get things
going and punt on the difficult stuff for the time being but YMMV.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20121029/d95241f4/attachment.sig>

  reply	other threads:[~2012-10-29 16:10 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-26  8:07 [RESEND][PATCH 0/2] Add spidev to the CFA-10049 Maxime Ripard
2012-10-26  8:07 ` Maxime Ripard
     [not found] ` <1351238873-25230-1-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2012-10-26  8:07   ` [PATCH 1/2] spi: spidev: Add device tree bindings Maxime Ripard
2012-10-26  8:07     ` Maxime Ripard
2012-10-27 22:19     ` Mark Brown
2012-10-27 22:19       ` Mark Brown
     [not found]       ` <20121027221955.GO4564-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
2012-10-29 15:26         ` Maxime Ripard
2012-10-29 15:26           ` Maxime Ripard
2012-10-29 16:10           ` Mark Brown [this message]
2012-10-29 16:10             ` Mark Brown
2012-10-26  8:07   ` [PATCH 2/2] ARM: dts: cfa10049: Add spidev to drive the DAC on SSP3 Maxime Ripard
2012-10-26  8:07     ` Maxime Ripard
  -- strict thread matches above, loose matches on Subject: below --
2012-10-18 13:59 [RESEND][PATCH 0/2] Add spidev to the CFA-10049 Maxime Ripard
     [not found] ` <1350568768-4374-1-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2012-10-18 13:59   ` [PATCH 1/2] spi: spidev: Add device tree bindings Maxime Ripard
2012-10-18 13:59     ` Maxime Ripard
     [not found]     ` <1350568768-4374-2-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2012-10-19  8:28       ` Shawn Guo
2012-10-19  8:28         ` Shawn Guo
2012-09-28 12:50 [PATCH 0/2] Add spidev to the CFA-10049 Maxime Ripard
     [not found] ` <1348836616-29783-1-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2012-09-28 12:50   ` [PATCH 1/2] spi: spidev: Add device tree bindings Maxime Ripard
2012-09-28 12:50     ` Maxime Ripard

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20121029161023.GC4511@opensource.wolfsonmicro.com \
    --to=broonie@opensource.wolfsonmicro.com \
    --cc=brian@crystalfontz.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=maxime.ripard@free-electrons.com \
    --cc=shawn.guo@linaro.org \
    --cc=spi-devel-general@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.