linux-kernel - Re: Toggling GPIO at 38Khz

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Message-ID: <48ECE71B.6030405@nortel.com>
Date:	Wed, 08 Oct 2008 11:00:11 -0600
From:	"Chris Friesen" <cfriesen@...tel.com>
To:	Jon Smirl <jonsmirl@...il.com>
CC:	Bill Gatliff <bgat@...lgatliff.com>,
	ARM Linux Mailing List 
	<linux-arm-kernel@...ts.arm.linux.org.uk>,
	lkml <linux-kernel@...r.kernel.org>
Subject: Re: Toggling GPIO at 38Khz

Jon Smirl wrote:

> The existing LIRC driver for a serial port is here:
> http://lirc.cvs.sourceforge.net/viewvc/lirc/lirc/drivers/lirc_serial/lirc_serial.c?view=markup

That driver basically does busy-wait bitbanging, using rdtsc on x86 if 
available or udelay() if not.

Your best bet is probably to use hrtimers combined with high res 
timestamps to correct for accumulated error.

Chris
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