[alsa-devel] Disabling HFL/R outputs in twl4030

Lopez Cruz, Misael x0052729 at ti.com
Fri May 22 12:31:35 CEST 2009

> > Currently, handsfree amplifiers are turned-on when the HandsfreeL/R
> > muxes are powered by the framework. I was thinking in adding a
> > dapm switch to select whether or not handsfree amplifiers should
> > be powered, but the switch probably is not the correct approach to
> > handle this situation. Maybe a regular kcontrol could be the answer.

> It has to be DAPM switch for muting the HFL and the HFR.
> In order to execute the pop removal on the HF outputs the bits in the HF
> registers has to be configured in a specific order (REF_EN, RAMP_EN, LOOP_EN
> and HB_EN)

> The DAPM switch should not change any register bits, but should have variable
> in the twl4030_priv struct to change.

Is it possible to have a dapm switch that doesn't affect register bits? I mean that the
kcontrol associated to the switch doesn't affect any register?

> I have the re-written HFL/R pop removal thing without the DAPM mute switch. I
> still need to test it on different HWs, but at least it does look promising at
> the moment.

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