From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Thu, 3 Aug 2006 13:25:26 -0500
From: Milton Miller <miltonm@bga.com>
To: dale@farnsworth.org, jean-baptiste.maneyrol@teamlog.com,
	Linuxppc-embedded@ozlabs.org,
Subject: Re: IBM OCP GPIO driver for linux 2.6
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On Thu Aug  3 2006 08:53:00 AM CDT, Dale Farnsworth wrote:
> The recommended way of accessing GPIO registers is to mmap them
> and manipulate them directly in user space.

> 		/* turn media led on */
> 		*reg_addr(p, OUTPUT_REG) &= ~MEDIA_LED_BIT;
> 		sleep(1);
> 		/* turn media led off */
> 		*reg_addr(p, OUTPUT_REG) |= MEDIA_LED_BIT;

Very racy if you need different bits in the same word controlled by different programs.

milton