From: nicolas.ferre@atmel•com (Nicolas Ferre)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] at91sam9g45: fix i2c bus speed
Date: Thu, 23 Sep 2010 10:18:21 +0200 [thread overview]
Message-ID: <4C9B0D4D.4050102@atmel.com> (raw)
In-Reply-To: <1285147886-17100-1-git-send-email-jacmet@sunsite.dk>
Le 22/09/2010 11:31, Peter Korsgaard :
> Use a correct udelay value to get bus speed around 100KHz. The udelay
> value was most likely copied from the older devices, but the 9g45
> is signicantly faster (400MHz, DDR, ..), so a udelay of 2 gives a
> bus speed of around 190KHz, which is too fast for some devices.
> A udelay value of 5 gives a bus speed of around 90KHz here.
>
> Signed-off-by: Peter Korsgaard <jacmet@sunsite•dk>
> ---
> arch/arm/mach-at91/at91sam9g45_devices.c | 4 ++--
By the way, I suspect that at91sam9g20 has the same issue (400MHz core
also)...
We may also have a look at at91sam9g10 which embeds a 266MHz core....
[..]
Best regards,
--
Nicolas Ferre
next prev parent reply other threads:[~2010-09-23 8:18 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
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 [this message]
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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