From mboxrd@z Thu Jan  1 00:00:00 1970
From: robherring2@gmail.com (Rob Herring)
Date: Wed, 11 May 2011 11:07:22 -0500
Subject: moving gpio driver to drivers/gpio, how to initialize?
In-Reply-To: <20110511142016.GG3188@pulham.picochip.com>
References: <20110511141153.GJ30963@pengutronix.de>
	<20110511142016.GG3188@pulham.picochip.com>
Message-ID: <4DCAB43A.8090003@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 05/11/2011 09:20 AM, Jamie Iles wrote:
> On Wed, May 11, 2011 at 04:11:53PM +0200, Sascha Hauer wrote:
>> I think we mostly agree on moving the gpio drivers from arch/arm to
>> drivers/gpio.  A question we have to answer is how we want to initialize
>> these drivers. On nomadik these are platform drivers, but on i.MX and
>> others platform drivers initialize too late, since the gpio functions
>> are already used at init_machine time. PXA uses sysdev for their gpios,
>> but is this the correct answer?
>
> The omap gpio driver registers the platform_driver as a
> postcore_initcall so that it can use GPIO in the machine init for this
> reason.  A platform_device/driver feels like the right way to do this
> IMHO.
>
An early_platform_device may be a better approach to avoid init level 
tweaking. This would be needed for timers if the SH timer approach is 
adopted.

Rob