On Thursday 02 July 2009 03:17:43 ext Candelaria Villareal, Jorge wrote:
According to TRM, an external FET controlled by a 1.8V output signal can be used to reduce the pop-noise heard when the audio amplifier is switched on. It is suggested that GPIO6 of TWL4030 be used, but any other gpio can be used instead. This is indicated in machine driver with the following twl4030_setup_data members:
-hs_extmute. Set to 1 if board has support for EXTMUTE.
-set_hs_extmute. Set to a callback funcion to control an external gpio line. Set to NULL if MUTE[GPIO6] pin is used.
Codec driver takes care of enabling and disabling this output during the headset pop attenuation sequence.
Also add a delay to let VMID settle in ramp up sequence.
I can not see any problems with this patch, but unfortunately I can not test it since none of my hardware supports the extmute on the headset output...
Thank you!
Acked-by: Peter Ujfalusi peter.ujfalusi@nokia.com