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From: Florian Vaussard <florian.vaussard-p8DiymsW2f8@public.gmane.org>
To: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
	Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH 1/2] gpiolib: add gpio_export_with_name
Date: Thu, 30 May 2013 11:19:33 +0200	[thread overview]
Message-ID: <51A719A5.50906@epfl.ch> (raw)
In-Reply-To: <20121126135911.2F1D33E187C@localhost>

Hello Grant,

On 11/26/2012 02:59 PM, Grant Likely wrote:
> On Wed, 21 Nov 2012 11:14:08 +0100, Jean-Christophe PLAGNIOL-VILLARD <plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org> wrote:
>> allow to specify a name to an exported gpio
>>
>> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>
>
> The gpio sysfs ABI is already horrible, racy, and unsafe. Really, we
> need a proper chrdev interface for controlling gpios. Sysfs is fine for
> poking around and experimenting, but we cannot provide any fine grained
> access control, locking or faster IO with the one-file-per-gpio sysfs
> model. So, no, I don't think this is a good idea to extend gpiolib in
> this way.
>

Would it make sense to provide only the DT binding to export a GPIO,
without changing the sysfs ABI? Even if work is progressing towards
having gpio-controlled reset pins [1], some boards still need GPIOs to
be exported to userspace for other functionalities.

Regards,

Florian

[1] http://article.gmane.org/gmane.linux.power-management.general/31364

  parent reply	other threads:[~2013-05-30  9:19 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-21 10:12 [PATCH 0/2] gpio: dt: add gpio-export support Jean-Christophe PLAGNIOL-VILLARD
     [not found] ` <20121121101259.GQ4398-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org>
2012-11-21 10:14   ` [PATCH 1/2] gpiolib: add gpio_export_with_name Jean-Christophe PLAGNIOL-VILLARD
2012-11-21 10:14     ` [PATCH 2/2] gpiolib-of: ad gpio-export support Jean-Christophe PLAGNIOL-VILLARD
2012-11-26 13:59     ` [PATCH 1/2] gpiolib: add gpio_export_with_name Grant Likely
2012-11-28 20:19       ` Jean-Christophe PLAGNIOL-VILLARD
     [not found]         ` <20121128201907.GF4398-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org>
2012-12-18  6:04           ` Jean-Christophe PLAGNIOL-VILLARD
     [not found]             ` <20121218060415.GM23971-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org>
2012-12-19 13:11               ` Grant Likely
2013-05-30  9:19       ` Florian Vaussard [this message]
     [not found]         ` <51A719A5.50906-p8DiymsW2f8@public.gmane.org>
2013-05-30 20:03           ` Linus Walleij
     [not found]             ` <CACRpkdb9F+wJ0hkNqPTP34r3JAEp2s07Q8U24fD6oCdj7MqCFA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-30 20:38               ` Florian Vaussard
     [not found]                 ` <51A7B8CD.4080702-p8DiymsW2f8@public.gmane.org>
2013-05-30 21:11                   ` Linus Walleij
     [not found]                     ` <CACRpkdZMj-Xin5PMDWavaWOTCSZF3NBWXk4fG4QXsJzhwBcs_Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-05-31  8:17                       ` Florian Vaussard
2012-11-21 14:43   ` [PATCH 0/2] gpio: dt: add gpio-export support Linus Walleij
2012-11-24 18:48     ` Jean-Christophe PLAGNIOL-VILLARD
     [not found]       ` <20121124184846.GC4398-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org>
2012-12-01 16:56         ` Linus Walleij

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