Re: [PATCH] RFC: interrupt consistency check for OF GPIO IRQs

From: Alexander Holler <holler@ahsoftware.de>
To: joelf@ti.com
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>,
	Linus Walleij <linus.walleij@linaro.org>,
	Grant Likely <grant.likely@linaro.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	Linux-OMAP <linux-omap@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Enric Balletbo i Serra <eballetbo@gmail.com>,
	Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>,
	Santosh Shilimkar <santosh.shilimkar@ti.com>,
	Kevin Hilman <khilman@linaro.org>, Balaji T K <balajitk@ti.com>,
	Tony Lindgren <tony@atomide.com>,
	Jon Hunter <jgchunter@gmail.com>
Subject: Re: [PATCH] RFC: interrupt consistency check for OF GPIO IRQs
Date: Wed, 11 Sep 2013 09:36:11 +0200	[thread overview]
Message-ID: <52301D6B.70305@ahsoftware.de> (raw)
In-Reply-To: <52301C13.2030103@ahsoftware.de>

Am 11.09.2013 09:30, schrieb Alexander Holler:
> And another small update. ;)
>
> Am 11.09.2013 09:16, schrieb Alexander Holler:
>
>>> To summarize what happens if a driver uses a gpio as irq:
>>>
>>> gpio_request() // This works only if the gpio was not requested before
>>> gpio_direction_input()
>>> gpio_to_irq() // This needs an irq-mapping
>>> request_threaded_irq()
>>>
>>> So I would suggest multiple steps to change that:
>>>
>>> 1. Create a mapping for every gpio found in DT (or all gpios if no DT is
>>> used). I think that is what Linus patch does (sorry, I haven't really
>>> followed this thread and didn't look in deep at the patch).
>>>
>>> 2. Implement gpio_request_for_irq()
>>> This would just be a small macro for gpio_request();
>>> gpio_direction_input()
>>>
>
> I would add gpio_to_irq() to that macro, so that it returns the irq
> number or zero if something failed.

Doing that, it would be easy to mark gpio_to_irq() as deprecated and 
driver authors would change automatically to use gpio_request_for_irq()
(or gpio_request_as_irq() which might more correct english).

So I would suggest just the two steps above, the first with the mapping 
and the second which introduces gpio_request_as_irq() and marks 
gpio_to_irq() as deprecated.

Everthing else I would leave out for the future (so I wouldn't request 
gpios centrally).

Regards,

Alexander Holler