From: alexandre.belloni@free-electrons.com (Alexandre Belloni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: at91: spi: request all csgpio in spi probe
Date: Thu, 31 Jul 2014 18:48:37 +0200 [thread overview]
Message-ID: <20140731164836.GI3214@piout.net> (raw)
In-Reply-To: <C5B462AE-B1D2-4067-91EB-44FDF49D28FA@jcrosoft.com>
On 01/08/2014 at 00:10:05 +0800, Jean-Christophe PLAGNIOL-VILLARD wrote :
> >>> While this solves the particular issue Ji?? is seeing, this will not
> >>> solve the case where PA14 (CS0) is not used by the spi driver at all. It
> >>> will remained muxed as CS0 and toggle when the spi master needs to
> >>> access CS0 until another driver muxes it to something else. I still
> >>> believe we should explicitly ask pinctrl to mux them as gpios.
>
> This is not the job of the kernel but to the bootloader
> no the pinctrl binding is not here and will never be here the configure a pin as a GPIO or
This is exactly what AT91_PERIPH_GPIO does though. Anyway, not request
the pinmuxing in the driver is not a good idea, then nothing prevents
another driver to request them to do something completely different.
> to a specific state. This the job of the driver or the bootloader
>
I agree that it must not allow to set the state, we are talking about
muxing.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
To: Jean-Christophe PLAGNIOL-VILLARD
<plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>
Cc: "Boris BREZILLON"
<boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
"Jiří Prchal"
<jiri.prchal-cKCO0sOKHLPtwjQa/ONI9g@public.gmane.org>,
"Nicolas FERRE"
<nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
"Mark Brown" <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
voice.shen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH] ARM: at91: spi: request all csgpio in spi probe
Date: Thu, 31 Jul 2014 18:48:37 +0200 [thread overview]
Message-ID: <20140731164836.GI3214@piout.net> (raw)
In-Reply-To: <C5B462AE-B1D2-4067-91EB-44FDF49D28FA-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>
On 01/08/2014 at 00:10:05 +0800, Jean-Christophe PLAGNIOL-VILLARD wrote :
> >>> While this solves the particular issue Jiří is seeing, this will not
> >>> solve the case where PA14 (CS0) is not used by the spi driver at all. It
> >>> will remained muxed as CS0 and toggle when the spi master needs to
> >>> access CS0 until another driver muxes it to something else. I still
> >>> believe we should explicitly ask pinctrl to mux them as gpios.
>
> This is not the job of the kernel but to the bootloader
> no the pinctrl binding is not here and will never be here the configure a pin as a GPIO or
This is exactly what AT91_PERIPH_GPIO does though. Anyway, not request
the pinmuxing in the driver is not a good idea, then nothing prevents
another driver to request them to do something completely different.
> to a specific state. This the job of the driver or the bootloader
>
I agree that it must not allow to set the state, we are talking about
muxing.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: "Boris BREZILLON" <boris.brezillon@free-electrons.com>,
devicetree@vger.kernel.org,
"Jiří Prchal" <jiri.prchal@aksignal.cz>,
"Nicolas FERRE" <nicolas.ferre@atmel.com>,
linux-kernel@vger.kernel.org, "Mark Brown" <broonie@kernel.org>,
voice.shen@atmel.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ARM: at91: spi: request all csgpio in spi probe
Date: Thu, 31 Jul 2014 18:48:37 +0200 [thread overview]
Message-ID: <20140731164836.GI3214@piout.net> (raw)
In-Reply-To: <C5B462AE-B1D2-4067-91EB-44FDF49D28FA@jcrosoft.com>
On 01/08/2014 at 00:10:05 +0800, Jean-Christophe PLAGNIOL-VILLARD wrote :
> >>> While this solves the particular issue Jiří is seeing, this will not
> >>> solve the case where PA14 (CS0) is not used by the spi driver at all. It
> >>> will remained muxed as CS0 and toggle when the spi master needs to
> >>> access CS0 until another driver muxes it to something else. I still
> >>> believe we should explicitly ask pinctrl to mux them as gpios.
>
> This is not the job of the kernel but to the bootloader
> no the pinctrl binding is not here and will never be here the configure a pin as a GPIO or
This is exactly what AT91_PERIPH_GPIO does though. Anyway, not request
the pinmuxing in the driver is not a good idea, then nothing prevents
another driver to request them to do something completely different.
> to a specific state. This the job of the driver or the bootloader
>
I agree that it must not allow to set the state, we are talking about
muxing.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2014-07-31 16:48 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-28 11:43 [PATCH] ARM: at91: spi: request all csgpio in spi probe Jiri Prchal
2014-07-28 11:43 ` Jiri Prchal
2014-07-28 11:43 ` Jiri Prchal
2014-07-28 12:21 ` Alexandre Belloni
2014-07-28 12:21 ` Alexandre Belloni
2014-07-28 12:21 ` Alexandre Belloni
2014-07-28 13:06 ` Jiří Prchal
2014-07-28 13:06 ` Jiří Prchal
2014-07-28 22:38 ` Alexandre Belloni
2014-07-28 22:38 ` Alexandre Belloni
2014-07-28 22:38 ` Alexandre Belloni
2014-07-29 8:00 ` Boris BREZILLON
2014-07-29 8:00 ` Boris BREZILLON
2014-07-29 8:00 ` Boris BREZILLON
2014-07-31 15:59 ` Alexandre Belloni
2014-07-31 15:59 ` Alexandre Belloni
2014-07-31 15:59 ` Alexandre Belloni
2014-07-31 16:10 ` Jean-Christophe PLAGNIOL-VILLARD
2014-07-31 16:10 ` Jean-Christophe PLAGNIOL-VILLARD
2014-07-31 16:48 ` Alexandre Belloni [this message]
2014-07-31 16:48 ` Alexandre Belloni
2014-07-31 16:48 ` Alexandre Belloni
2014-07-31 17:05 ` Jean-Christophe PLAGNIOL-VILLARD
2014-07-31 17:05 ` Jean-Christophe PLAGNIOL-VILLARD
2014-07-31 17:05 ` Jean-Christophe PLAGNIOL-VILLARD
2014-07-29 11:32 ` Mark Brown
2014-07-29 11:32 ` Mark Brown
2014-07-28 15:06 ` Boris BREZILLON
2014-07-28 15:06 ` Boris BREZILLON
2014-07-28 15:06 ` Boris BREZILLON
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=20140731164836.GI3214@piout.net \
--to=alexandre.belloni@free-electrons.com \
--cc=linux-arm-kernel@lists.infradead.org \
/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.