All of lore.kernel.org
 help / color / mirror / Atom feed
From: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
To: Baruch Siach <baruch@tkos.co.il>
Cc: Mark Brown <broonie@kernel.org>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	linux-samsung-soc@vger.kernel.org,
	Doug Anderson <dianders@chromium.org>,
	linux-kernel@vger.kernel.org, Kukjin Kim <kgene@kernel.org>,
	Olof Johansson <olof@lixom.net>,
	David Hendricks <dhendrix@google.com>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org
Subject: Re: [RFC PATCH 1/4] spi: spidev: Add Google SPI flash compatible string
Date: Wed, 20 May 2015 09:35:57 +0200	[thread overview]
Message-ID: <555C395D.9080409@collabora.co.uk> (raw)
In-Reply-To: <20150519195305.GA2586@tarshish>

Hello Baruch,

On 05/19/2015 09:53 PM, Baruch Siach wrote:
> Hi Javier,
> 
> On Tue, May 19, 2015 at 03:34:11PM +0200, Javier Martinez Canillas wrote:
>> Google Chromebooks have a SPI flash that is used to store firmware and
>> different system parameters and data (i.e: Google Binary Block flags).
>> 
>> Since there isn't a driver for it yet, the spidev interface is used to
>> access the flash from user-space (i.e: using the flashrom tool).
>> 
>> Add a "google,spi-flash" compatible string so the Device Tree sources
>> use it instead of the "spidev" compatible which does not describe the
>> real HW and is just a Linux implementation detail.
>> 
>> A generic "google,spi-flash" OF device ID is used instead of the actual
>> vendor/model because these chips are commodity parts that are sourced
>> from multiple vendors. So specifying the exact vendor and model in the
>> DTS will add a maintenance burden with no real gain (the parts are 100%
>> compatible anyways) and will likely result in it simply being wrong for
>> a sizeable fraction of the machines.
> 
> The compatible string and dt binding should be documented somewhere under 
> Documentation/devicetree/bindings/. Also, please keep the dt list on Cc for dt 
> related patches.
>

Yes, I didn't add a binding doc because this is mostly a RFC to see if
Mark finds the approach feasible but yes I should had included anyways,
sorry about that.

I'll add when posting as a proper patch if he agrees with the solution.
 
> baruch
> 

Best regards,
Javier

WARNING: multiple messages have this Message-ID (diff)
From: javier.martinez@collabora.co.uk (Javier Martinez Canillas)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 1/4] spi: spidev: Add Google SPI flash compatible string
Date: Wed, 20 May 2015 09:35:57 +0200	[thread overview]
Message-ID: <555C395D.9080409@collabora.co.uk> (raw)
In-Reply-To: <20150519195305.GA2586@tarshish>

Hello Baruch,

On 05/19/2015 09:53 PM, Baruch Siach wrote:
> Hi Javier,
> 
> On Tue, May 19, 2015 at 03:34:11PM +0200, Javier Martinez Canillas wrote:
>> Google Chromebooks have a SPI flash that is used to store firmware and
>> different system parameters and data (i.e: Google Binary Block flags).
>> 
>> Since there isn't a driver for it yet, the spidev interface is used to
>> access the flash from user-space (i.e: using the flashrom tool).
>> 
>> Add a "google,spi-flash" compatible string so the Device Tree sources
>> use it instead of the "spidev" compatible which does not describe the
>> real HW and is just a Linux implementation detail.
>> 
>> A generic "google,spi-flash" OF device ID is used instead of the actual
>> vendor/model because these chips are commodity parts that are sourced
>> from multiple vendors. So specifying the exact vendor and model in the
>> DTS will add a maintenance burden with no real gain (the parts are 100%
>> compatible anyways) and will likely result in it simply being wrong for
>> a sizeable fraction of the machines.
> 
> The compatible string and dt binding should be documented somewhere under 
> Documentation/devicetree/bindings/. Also, please keep the dt list on Cc for dt 
> related patches.
>

Yes, I didn't add a binding doc because this is mostly a RFC to see if
Mark finds the approach feasible but yes I should had included anyways,
sorry about that.

I'll add when posting as a proper patch if he agrees with the solution.
 
> baruch
> 

Best regards,
Javier

  reply	other threads:[~2015-05-20  7:36 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-19 13:34 [RFC PATCH 0/4] Add SPI flash support for Exynos Chromebooks Javier Martinez Canillas
2015-05-19 13:34 ` Javier Martinez Canillas
2015-05-19 13:34 ` [RFC PATCH 1/4] spi: spidev: Add Google SPI flash compatible string Javier Martinez Canillas
2015-05-19 13:34   ` Javier Martinez Canillas
2015-05-19 19:53   ` Baruch Siach
2015-05-19 19:53     ` Baruch Siach
2015-05-20  7:35     ` Javier Martinez Canillas [this message]
2015-05-20  7:35       ` Javier Martinez Canillas
2015-05-20 10:13   ` Mark Brown
2015-05-20 10:13     ` Mark Brown
2015-05-20 10:18     ` Javier Martinez Canillas
2015-05-20 10:18       ` Javier Martinez Canillas
2015-05-20 10:37       ` Mark Brown
2015-05-20 10:37         ` Mark Brown
2015-05-20 11:21         ` Javier Martinez Canillas
2015-05-20 11:21           ` Javier Martinez Canillas
2015-05-20 11:41           ` Mark Brown
2015-05-20 11:41             ` Mark Brown
2015-05-19 13:34 ` [RFC PATCH 2/4] ARM: dts: Add SPI flash node for Peach boards Javier Martinez Canillas
2015-05-19 13:34   ` Javier Martinez Canillas
2015-05-20  3:37   ` Krzysztof Kozlowski
2015-05-20  3:37     ` Krzysztof Kozlowski
2015-05-20 10:17     ` Javier Martinez Canillas
2015-05-20 10:17       ` Javier Martinez Canillas
2015-05-21  0:44       ` Krzysztof Kozlowski
2015-05-21  0:44         ` Krzysztof Kozlowski
2015-05-19 13:34 ` [RFC PATCH 3/4] ARM: dts: Add SPI flash node to exynos5250-snow Javier Martinez Canillas
2015-05-19 13:34   ` Javier Martinez Canillas
2015-05-20  3:38   ` Krzysztof Kozlowski
2015-05-20  3:38     ` Krzysztof Kozlowski
2015-05-19 13:34 ` [RFC PATCH 4/4] ARM: exynos_defconfig: Enable user mode SPI device support Javier Martinez Canillas
2015-05-19 13:34   ` Javier Martinez Canillas
2015-05-20  3:38   ` Krzysztof Kozlowski
2015-05-20  3:38     ` Krzysztof Kozlowski

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=555C395D.9080409@collabora.co.uk \
    --to=javier.martinez@collabora.co.uk \
    --cc=baruch@tkos.co.il \
    --cc=broonie@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=dhendrix@google.com \
    --cc=dianders@chromium.org \
    --cc=k.kozlowski@samsung.com \
    --cc=kgene@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-samsung-soc@vger.kernel.org \
    --cc=olof@lixom.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.