On Thursday 12 January 2012 03:58 AM, Kevin Hilman wrote: > Shubhrajyoti D <shubhrajyoti@xxxxxx> writes: > >> From: Vikram Pandita <vikram.pandita@xxxxxx> >> >> 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@xxxxxx> >> Signed-off-by: Vikram Pandita <vikram.pandita@xxxxxx> >> Signed-off-by: Jon Hunter <jon-hunter@xxxxxx> >> Signed-off-by: Shubhrajyoti D <shubhrajyoti@xxxxxx> >> --- >> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
