[alsa-devel] [PATCH 1/1] ASoC: TWL4030: Wait RAMP_DELAY on headsetl_event: POST_PMD

[Peter Ujfalusi]

On Thursday 14 May 2009 12:56:21 ext Mark Brown wrote:
> On Thu, May 14, 2009 at 12:48:49PM +0300, Peter Ujfalusi wrote:
> > This is not really possible with the twl4030 codec.
> > For simplicity, let's take the Audio left2 route:
> > DACL2 -> PGAL2 ---> PreDriveL
> >
> >                 |-> PreDriveR
> >                 |-> HeadsetL
> >                 |-> CarkitL
> >                 |-> HandsFreeL
> >                 |-> HandsFreeR
> >
> >                 \-> Earpiece
> >
> > At least the Headset and HandsFree needs special mantra for the pop
> > removal. If the Headset is not connected/used than there is no need to do
> > the HS pop attenuation.
>
> The event could check the current setup and do whatever's appropriate?

I have to think about this, but at first sight it does look awfully 
complicated thing to do (4 PGA, 7 output with mixers, 2+1 output mux)...

> BTW, since you're saying the required ramp time is clock dependent
> shouldn't it also be possible to configure the ramp time automatically
> based on the clock that's been configured?

The patch that I have sent is calculating the needed delay based on the MCLK + 
RAMP_DELAY value.
I think I don't want to fixate the ramp delay to any value (meaning that the 
delay would last around 50ms). This seams to be also board specific, so I 
would rather leave this to the user to find the best value for the given 
board.

-- 
Péter