From: plagnioj@jcrosoft.com (Jean-Christophe PLAGNIOL-VILLARD)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] at91sam9g45: fix i2c bus speed
Date: Wed, 22 Sep 2010 18:09:04 +0200 [thread overview]
Message-ID: <20100922160904.GU32018@game.jcrosoft.org> (raw)
In-Reply-To: <20100922145442.GA3753@debian-wegner1.datadisplay.de>
On 16:54 Wed 22 Sep , Wolfgang Wegner wrote:
> Hi,
>
> On Wed, Sep 22, 2010 at 04:34:06PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > On 13:08 Wed 22 Sep , Peter Korsgaard wrote:
> [...]
> > > Now, I agree that it would be nice to add an interface to tweak this
> > > delay if needed (extra argument to at91_add_device_i2c()?), but that's
> > > next to the discussion about what the default should be.
> > I'd prefer to calculate it
> >
> > so we specify which max freq we want in my mind it will be good to be as in
> > spi to specific per device it's max speed so we can adapt the bus freq
>
> sorry in case I got you wrong, but please keep in mind that in
> contrast to SPI the addressing in I2C is done via the serial data,
> so the bus speed has to be _permanently_ adapted to match the
> slowest device present.
yeah that's the idea but each i2c device specify it's speed then we put the
bus speed at the lowest
Best Regards,
J.
next prev parent reply other threads:[~2010-09-22 16:09 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-22 9:31 [PATCH] at91sam9g45: fix i2c bus speed Peter Korsgaard
2010-09-22 10:48 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 11:08 ` Peter Korsgaard
2010-09-22 14:34 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 14:54 ` Wolfgang Wegner
2010-09-22 16:09 ` Jean-Christophe PLAGNIOL-VILLARD [this message]
2010-09-22 15:18 ` Peter Korsgaard
2010-09-22 16:05 ` Nicolas Ferre
2010-09-22 16:10 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-22 16:06 ` Nicolas Ferre
2010-09-23 8:18 ` Nicolas Ferre
2010-09-23 9:22 ` Peter Korsgaard
2010-09-23 9:31 ` Russell King - ARM Linux
2010-09-23 10:09 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 10:24 ` Peter Korsgaard
2010-09-23 10:21 ` Peter Korsgaard
2010-09-23 10:36 ` Russell King - ARM Linux
2010-09-23 10:54 ` Peter Korsgaard
2010-09-23 11:16 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 11:32 ` Peter Korsgaard
2010-09-23 12:00 ` Jean-Christophe PLAGNIOL-VILLARD
2010-09-23 11:07 ` Jean-Christophe PLAGNIOL-VILLARD
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