[PATCH v2 1/2] i2c-mv64xxx: Fix timing issue on Armada XP (errata FE-8471889)

Wolfram Sang wsa at the-dreams.de
Wed Jun 19 06:24:17 EDT 2013


On Tue, Jun 18, 2013 at 05:40:23PM +0200, Gregory CLEMENT wrote:
> From: Zbigniew Bodek <zbb at semihalf.com>
> 
> All the Armada XP (mv78230, mv78260 and mv78460) have a silicon issue
> in the I2C controller which violate the i2c repeated start
> timing. The I2C standard requires a minimum of 4.7us for the repeated
> start condition whereas the I2C controller of the Armada XP this time
> is 2.9us.
> 
> So this patch adds a 5us delay for the start case only if the
> mv64xxx_i2c_errata_delay flag is set.

You are correct that this does not need a seperate property since this
is a flaw of this specific controller. So, it needs a new compatible
entry ('mv78230-i2c' for example) and this entry should then have the
workaround enabled.

Thanks,

   Wolfram

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