WM8750 utilization

WM8750 utilization

[Harald Radke]

Hi there!

Sorry, if this is the wrong list for this, just tell me if so (and maybe point 
out where to go instead *g*).

I am trying to improve usage of the wm8750 codec on my Loox720 PDA. Its a 
PXA272 device. So far WM8750 driver works quite ok (via I2S), however there 
are some things that are kinda strange.

The Loox720 has a headphone jack, a earpiece and a speaker.

When driving LOUT1/ROUT1, sound goes via headphones, LOUT2/ROUT2 drives the 
earpiece. When setting OUT3 on ROUT1, the speaker plays fine.

Strange: 

- when disabling either LOUT2 or ROUT2 (while the other is enabled), the 
speaker plays the sound (not sure if the earpiece still is active as speaker 
output is much louder, but I think so)

- when disabling ROUT1/LOUT1 with LOUT2/ROUT2 active, the earpiece plays fine, 
however there is still some output on the headphone (really really silently)

- Trying to utilize headphone switch via the WM8750 registers doesn't really 
work ): depending on the polarity bit either one of the OUTs is either not 
muted at all or activated at all.

Any ideas or hints?

Thanks a lot!

Harald Radke

Re: WM8750 utilization

[Mark Brown]

On Fri, Aug 15, 2008 at 06:32:37PM +0200, Harald Radke wrote:

> The Loox720 has a headphone jack, a earpiece and a speaker.

Please post your machine driver.  If you are doing code modifications to
make any of the changes you discuss below please also show these
changes.

> When driving LOUT1/ROUT1, sound goes via headphones, LOUT2/ROUT2 drives the 
> earpiece. When setting OUT3 on ROUT1, the speaker plays fine.

Could you please also clarify how the hardware is connected up here?
Which outputs on the device are connected to each of the headphone,
speaker and earpiece?

> - Trying to utilize headphone switch via the WM8750 registers doesn't really 
> work ): depending on the polarity bit either one of the OUTs is either not 
> muted at all or activated at all.

Are you sure that HPDETECT is wired up correctly and that the expected
level change occurs on it when the jack is inserted and removed?