[alsa-devel] Cherry Trail + RT5645 devices with a mono speaker ?

[Bard Liao]

> -----Original Message-----
> From: Hans de Goede [mailto:hdegoede at redhat.com]
> Sent: Sunday, October 15, 2017 2:12 AM
> To: Pierre-Louis Bossart; Bard Liao
> Cc: alsa-devel at alsa-project.org
> Subject: Cherry Trail + RT5645 devices with a mono speaker ?
> 
> Hi Pierre-Louis, Bard,
> 
> I've been looking into getting some Cherry Trail + RT5645
> devices with a mono speaker I have to work properly.
> 
> Specifically the goal is to mix the right channel into
> the left output, so that sounds which are only played
> over the right channel do not get lost.
> 
> I'm using this UCM file:
> https://github.com/plbossart/UCM/blob/master/byt-rt5640/HiFi
> 
> Looking at the rtl5640 UCM file, getting the mono speaker
> to work (in a first simple attempt) should be as simple
> as replacing:
> 
>                  cset "name='SPOR MIX SPKVOL R Switch' on"
> 
> With
> 
>                  cset "name='SPOL MIX SPKVOL R Switch' on"
> 
> But this does not work, the speaker test sound for the
> right speaker is still silent (works with headphones).
> 
> I've also looked into directly poking the
> RT5645_SPO_MIXER i2c register for testing, but when
> checking its value with the original unmodified UCM
> file:
> 
> [root at localhost ~]# i2cget -y -f 1 0x1a 0x48  w
> 0x06c8
> 
> That is: 0xc806 as the output of i2cget "w" mode
> needs byteswapping. Note that both the
> RT5645_M_SV_L_SPM_L and RT5645_M_SV_R_SPM_L bits
> are already cleared, which is weird as this is
> before I've modified anything. Also the
> RT5645_M_SV_R_SPM_R bit is cleared, but that is
> expected.
> 
> Even if I manually set reg 0x48 to 0x07c8 which AFAIK
> should enable output of both left and right channels
> on the left speaker I still only get sounds played
> on the left channel.
> 
> Any insights / help with this would be very much
> welcome.

Could you dump all registers for us?


> 
> Regards,
> 
> Hans
> 
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