[alsa-devel] Cherry Trail + RT5645 devices analog microphone not working.

[Hans de Goede]

Hi,

On 25-12-17 03:15, Bard Liao wrote:
>> -----Original Message-----
>> From: Hans de Goede [mailto:hdegoede at redhat.com]
>> Sent: Sunday, December 24, 2017 6:43 PM
>> To: Bard Liao
>> Cc: Pierre-Louis Bossart; alsa-devel at alsa-project.org
>> Subject: Cherry Trail + RT5645 devices analog microphone not working.
>>
>> Hi Bard,
>>
>> I've been looking into getting the microphone to work on
>> some Cherry Trail + RT5645 devices with what appears to
>> be a simple analog microphone.
>>
>> You can see the microphone on one of the models I'm trying
>> to get it to work on soldered onto the right side of the PCB
>> here: https://i.imgur.com/bJzBQWe.jpg
>>
>> I'm using this ucm config:
>>
>> https://fedorapeople.org/~jwrdegoede/chtrt5645/
>>
>> Which is basically Pierre-Louis Bossart's config from:
>> https://github.com/plbossart/UCM
>>
>> Adjusted because the devices all have a mono speaker.
>>
>> I've been trying to get this to work myself and I can get
>> some sound while recording by adding:
>>
>>                   cset "name='RECMIXL BST2 Switch' on"
>>                   cset "name='RECMIXR BST2 Switch' on"
>>
>> But then I mainly get noise, I do get some sound from the
>> microphone if I talk really really loudly, but it is
>> barely above the noise-floor. I've the feeling that BST2
>> is only picking up the microphone via cross-talk and
>> that BST1 indeed is the correct input, but for some reason
>> I get complete silence when recording when only BST1 is
>> selected in the RECMIXR, and yes I've checked / set the
>> "IN1 boost volume".
>>
>> TL;DR: I'm trying to get an analog mic to work on 3
>> different models Cherry Trail + RT5645 devices and I've
>> been unable to get this to work. I've put a registerdump
>> of the rt5645 with gnome-sound-recorder running here:
>> https://fedorapeople.org/~jwrdegoede/rt5645-mic-red.dump
>>
>> Any insights / help with this would be very much
>> welcome.
> 
> I don't have the schematic, but I think you probably need micbias
> for the capture. Please add both "micbias1" and "micbias2" in
> the audio route since I don't know which one is needed.
> for example
> static const struct snd_soc_dapm_route cht_rt5645_audio_map[] = {
> ...
> 	{"Int Mic", NULL, "micbias1"},
> 	{"Int Mic", NULL, "micbias2"},
> ...
> };

Thank you for your reply. I've tested this, but unfortunately it
does not help.

Do you perhaps have a cherrytrail device withrt5645 codec where you
can test an analog mic input with the upstream driver + latest ucm
file from Pierre-Louis with yourself ? I've the feeling that this is
not specific to the 3 devices I've access to but a general problem
in the driver and/or the ucm files.

Regards,

Hans