[alsa-devel] Update on TLV320AIC3204 Driver

[Stuart Longland]

On Tue, Jun 15, 2010 at 04:42:32PM +0300, Peter Ujfalusi wrote:
> Hi,
> 
> On Tuesday 15 June 2010 08:11:10 ext Stuart Longland wrote:
> > Okay, I've had a close inspection of how the SOC_DOUBLE_R_SX_TLV widgets
> > are implemented.  I couldn't find where in the git trees the control had
> > been added, I wound up applying this patch myself in my tree... it
> > apparently got applied in the official trees, but I cannot find it.
> 
> I'm not really sure what the SOC_DOUBLE_R_SX_TLV is for... 
> But would a simple SOC_DOUBLE_R_TLV enough for the aic3204 codec?
> I have not looked at the datasheet (if it is available), but I'll try to find 
> it.

http://focus.ti.com/docs/prod/folders/print/tlv320aic3204.html has the
datasheet.

As I mentioned; the bitfields are signed integers, 6 bits wide in the
case of the example given, there are some that are 7 bits.

In the examples that I gave (driver gain settings), they have a range of
-6dB to 29dB... which corresponds to bitfield values of 0x3a (for -6dB)
and 0x1d (for 29dB).

I did try using the regular TLV macro, and found that the volume
"wrapped" around in a very undesirable fashion.  SOC_DOUBLE_R_SX_TLV was
the suggestion made at the time[1].  The way it is now, it works okay
...  if you leave the mute untouched.
-- 
Stuart Longland (aka Redhatter, VK4MSL)      .'''.
Gentoo Linux/MIPS Cobalt and Docs Developer  '.'` :
. . . . . . . . . . . . . . . . . . . . . .   .'.'
http://dev.gentoo.org/~redhatter             :.'

I haven't lost my mind...
  ...it's backed up on a tape somewhere.

1. http://article.gmane.org/gmane.linux.alsa.devel/73640