From: khilman@ti•com (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] I2C: OMAP: Recover from Bus Busy condition
Date: Wed, 11 Jan 2012 14:28:20 -0800 [thread overview]
Message-ID: <87vcoh27sr.fsf@ti.com> (raw)
In-Reply-To: <1326303693-30106-1-git-send-email-shubhrajyoti@ti.com> (Shubhrajyoti D.'s message of "Wed, 11 Jan 2012 23:11:33 +0530")
Shubhrajyoti D <shubhrajyoti@ti•com> writes:
> From: Vikram Pandita <vikram.pandita@ti•com>
>
> In case a peripheral is driving SDA bus low (ie. a start condition), provide
> a constant clock output using the test mode of the OMAP I2C controller to
> try and clear the bus. Soft reset I2C controller after attempting the bus clear
> to ensure that controller is in a good state.
>
> Based upon Vikram Pandita's patch from TI Android 3.0 kernel and modified for
> mainline by Jon Hunter.
>
> A couple differences from the original patch ...
> 1. Add a new function for bus clear
> 2. Ensure that the CON.I2C_EN bit is set when using the SYSTEST feature to
> output a permanent clock. This bit needs to be set and tpyically it would
> be set by the unidle function but this is not the case for all OMAP
> generations.
> 3. Program the SYSTEST setting only the bits we care about. However, restore
> SYSTEST registers to there original state as some OMAP generations do not
> implement perform a soft-reset.
> 4. Clear the CON register after performing the bus clear, so when we call the
> init function the controller is disabled and the init function will
> re-enable later.
>
> Cc: Kevin Hilman <khilman@ti•com>
> Signed-off-by: Vikram Pandita <vikram.pandita@ti•com>
> Signed-off-by: Jon Hunter <jon-hunter@ti•com>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti•com>
> ---
> Original patch can be found here:
> http://git.omapzoom.org/?p=kernel/omap.git;a=commit;h=a2ab04192ba25e60f95ba1ff3af5601a2d7b5bd1
> applies on Kevin's for_3.3/i2c/misc
Please also explain how this was tested, and on what platforms.
Thanks,
Kevin
next prev parent reply other threads:[~2012-01-11 22:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 17:41 [PATCH v2] I2C: OMAP: Recover from Bus Busy condition Shubhrajyoti D
2012-01-11 22:28 ` Kevin Hilman [this message]
2012-01-12 6:07 ` Shubhrajyoti
-- strict thread matches above, loose matches on Subject: below --
2012-01-11 17:42 Shubhrajyoti D
2012-01-12 5:55 ` Shubhrajyoti
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