From: shubhrajyoti@ti•com (Shubhrajyoti)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] I2C: OMAP: Recover from Bus Busy condition
Date: Thu, 12 Jan 2012 11:37:30 +0530 [thread overview]
Message-ID: <4F0E78A2.6050900@ti.com> (raw)
In-Reply-To: <87vcoh27sr.fsf@ti.com>
On Thursday 12 January 2012 03:58 AM, Kevin Hilman wrote:
> 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.
Please ignore will resend.
> Thanks,
>
> Kevin
next prev parent reply other threads:[~2012-01-12 6:07 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
2012-01-12 6:07 ` Shubhrajyoti [this message]
-- 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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