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From: craig@hollabaugh.com (Dr. Craig Hollabaugh)
To: Dan Malek <dan@embeddededge.com>
Cc: joakim.tjernlund@lumentis.se,
	Barker Michael-r43496 <Michael.D.Barker@motorola.com>,
	linuxppc-embedded@lists.linuxppc.org
Subject: Re: 8xx i2c refers to unspecified chip errata
Date: Thu, 10 Oct 2002 10:35:42 -0600 (MDT)	[thread overview]
Message-ID: <20021010163542.A6F4027C52@chuy.ouraynet.com> (raw)
In-Reply-To: <3DA5A858.50802@embeddededge.com>


> Joakim Tjernlund wrote:
>
>  > .... The driver(i2c-algo-8xx.c) that
> > comes with the kernel has other severe bugs(memory corruption etc.) as well.
>

Dan Wrote
> Just toggle the bits in software.  I never saw an application where the I2C
> controller provided a performance advantage.  It's lots of software to execute,
> along with all of the interrupt handling and stuff, so you just spend lots of
> overhead not making any other progress.
>
> Make sure you carefully analyze the entire system performance advantages.
> Using the controller assitance just because it is there isn't always the
> proper solution.  Same is true for the SPI.


Here's a link to my book's I2C bit banging code for 8xx
http://www.embeddedlinuxinterfacing.com/chapters/10/SAA1064_rpxcllf.c

You can pull the I2C routines from this code.

Let me know if you have any questions.
Craig


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

  reply	other threads:[~2002-10-10 16:35 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-10-09 20:14 8xx i2c refers to unspecified chip errata Barker Michael-r43496
2002-10-10 10:35 ` Joakim Tjernlund
2002-10-10 16:18   ` Dan Malek
2002-10-10 16:35     ` Dr. Craig Hollabaugh [this message]
2002-10-11  7:28     ` Joakim Tjernlund
2002-10-11  7:50       ` bart
2002-10-11  9:12         ` Joakim Tjernlund
2002-10-11  9:56           ` bart
2002-10-11 12:02           ` Stephan Linke
2002-10-11 12:14             ` bart
2002-10-11 12:31               ` Stephan Linke
2002-10-11 12:46                 ` Joakim Tjernlund
2002-10-11 12:44             ` Joakim Tjernlund
2002-10-11 12:55               ` bart
2002-10-11 13:10                 ` Joakim Tjernlund
2002-10-15 16:57           ` Tom Rini
2002-10-22  9:15             ` Joakim Tjernlund
2002-10-24 16:10               ` Tom Rini
2002-10-24 18:21                 ` Joakim Tjernlund
2002-11-01 11:01                   ` Joakim Tjernlund
2002-11-01 19:19                     ` Tom Rini
2002-11-17 20:51                   ` Mark D. Studebaker
2002-11-17 21:44                     ` Joakim Tjernlund
2002-11-18 14:10                       ` Tom Rini
2002-11-18 19:04                         ` Mark D. Studebaker
2002-11-18 19:24                           ` Joakim Tjernlund
2002-11-18 19:31                             ` Tom Rini
2002-11-18 19:42                             ` Jean Delvare
2002-11-18 19:46                               ` Tom Rini
  -- strict thread matches above, loose matches on Subject: below --
2002-10-10 17:01 Barker Michael-r43496

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