Re: Nokia N900 - audio TPA6130A2 problems

Pali Rohár
2016-03-17T13:01:23Z

On Thursday 17 March 2016 09:56:22 Ivaylo Dimitrov wrote:
> Hi,
>
> On 17.03.2016 02:49, Sebastian Reichel wrote:
> >
> >mh both, the power gpio is turned off in tpa6130a2_power(0). I guess
> >if you don't see the problem during probe() everything works?
> >
> >I have another idea though: In opposit to the gpio, the regulator
> >may also be referenced by something else/already enabled. I guess
> >adding a sleep after the regulator_enable() is worth a try.
> >
> >Also I wonder if the same happens, if you avoid having the module
> >available during boot and instead load it once everything has
> >settled. That would rule out any side-effects of other modules
> >being probed on the same i2c bus.
>
>
> Well, I think I've figured it out - input pullups are not enabled
> on i2c bus pins, in stock kernel we have:
>
> ./devmem2 0x480021BC
> Value at address 0x480021BC (0x4001f1bc): 0x1180118
>
> ./devmem2 0x480021C0
> Value at address 0x480021C0 (0x4001f1c0): 0x1180118
>
> in mainline
>
> ./devmem2 0x480021BC
> Value at address 0x480021BC (0xb6ff01bc): 0x1000100
>
> ./devmem2 0x480021C0
> Value at address 0x480021C0 (0xb6f6d1c0): 0x1000100
>
> I wonder how i2c devices work at all :)

Is camera on same bus as tpa? Maybe this is reason why camera is
non-functional too?

> Will fix the board DTS file later on an will report

Thanks for investigation! Is that problem in both DTS and also legacy
board code?

--
Pali Rohár
pali.rohar@gmail.com