wm8944 audio codec not detected

The wm8944 audio codec is not detected on the i2c bus:

[ 1.602411] qup_i2c qup_i2c.0: QUP: I2C status flags :0x1300c8, irq:187
[ 1.609003] qup_i2c qup_i2c.0: I2C slave addr:0x1a not connected
[ 1.614924] wm8944 0-001a: Failed to read ID register
[ 1.620235] wm8944: probe of 0-001a failed with error -107

Any idea what is wrong ? We are for the moment using version 15.08. Note that the other devices on the i2c bus are detected OK.


Which type of AirPrime module are you using?

Could you provide the answer of the “cm info” command?

If you are using AirPrime WP8548 module on mangOH board (PCB REV 2) then it seems that the WM8944 audio codec I2C lines are not connected.
See the mangOH schematics (REV 2), on Sheet #5 you can see that R560 and R561 resistors are labeled as “DNI” (do not install).
This will explain the error messages about missing device at 0x1a address.


I have a Rev 2 board with the WP8548 module, so this is very likely the problem. Where can I find the missing resistors on the board ?


PS: since the wm8944 codec is not connected, is this codec going to be removed on the next HW revision ?

Components location is available in the PCB doc (CCA_1600643-3_SHT2.pdf)

R560 and R561 are located on the bottom side, close to the audio codec chip (U501):