Re: Nokia N900 sound driver and ECI GPIOs

[Peter Ujfalusi]

On 01/02/2017 02:58 PM, Pali RohÃr wrote:
> On Monday 02 January 2017 14:53:44 Peter Ujfalusi wrote:
>> On 01/02/2017 10:51 AM, Pali RohÃr wrote:
>>> On Monday 02 January 2017 10:34:34 Peter Ujfalusi wrote:
>>>> On 01/02/2017 12:36 AM, Pavel Machek wrote:
>>>>> Are there multi-button headsets compatible with N900?
>>>>
>>>> Not sure if n900 is capable of handling ECI communication, n9 was. In n9
>>>> the PMIC/Audio chip had an ECI core integrated afaik
>>>
>>> In N9 it is handled by twl5030 chip? Is there documentation for that
>>> ECI/ACI part? N900 has twl4030 so we need some chip documentation for
>>> adding support for N900...
>>
>> n9 has twl5031 and the documentation is not public. But the kernel
>> source from Nokia have the driver under drivers/mfd/twl5031-aci.c It is
>> using the ECI stack to report the changes.
>> twl4030 and twl5030 does not have support for ECI, only twl5031.
> 
> Ok, so Nokia N900's audio chip (twl4030) does not have support for ECI.

TLV320AIC34 (two of them) on n900 to be precise, n9 uses twl5031 and
tlv320dac33.

> But still as Jarkko wrote there could be an option to supports ECI via
> GPIO and ADC.

Yes, there is the option, but w/o documentation on the ECI protocol it
is not going to be easy. And I'm sure there were a (good) reason the
n900 does not support ECI. If it could be done in a stable way the
product would have support for it.

> And there is still mysterious gpio 178 (RX51_ECI_SWITCH_1_GPIO) which
> could help us?

Yeah, that is something I have no idea what it is for. It could be that
the schema is using different pin mode for it? It might worth looking at
the TRM on which pin the gpio_178 can go out and look for the possible
modes? Most likely waste of time...

> 

-- 
PÃter