IMX6SL-EVK, mainline kernel and WM8962

[bjornha]

Hi!

I have at hand an i.MX6SL evaluation board with the WM8962 audio codec.

I debootstrapped me a debian image with a vanilla kernel 3.12.2 using an unmodified copy of the "imx_v6_v7_defconfig" (# grep SND .config) that ships with the kernel. This boots like a charm and most things seem to work just fine, with the exception that the audio codec is never detected. no cards in /proc/asound/cards, dmesg says nothing about the WM8962 and /dev/snd/ contains nothing of relevance. Now, I was under the impression that the mainline kernels have now incorporated all the required/related drivers for the i.MX6 series, is this wrong? What changes to kernel configuration do I need to incorporate to have this codec detected as an alsa/asoc audio device? is "imx_v6_v7_defconfig" incompatible with 6SL?

Also I noticed that imx6sl support was only added to the mainline kernel tree in 3.11, so it's relatively new. If none of this pans out with mainline kernel, I presume the only option is resorting to the older freescale specific 3.0.x branch?

Any hints most welcome. Thanks for your time.

[fabio_estevam]

Hi Bjørn,

You can take a look at the imx6qdl-sabresd.dts file as reference, as it supports wm8962. Then you can add it the support to imx6sl-evk.dts.

Regards,

Fabio Estevam

[sinanakman]

Fabio, I am just testing sabresd with mainline tot (3.14.0-rc6+). Just tried speaker-test, aplay etc. but nothing comes out of headphone. I an see see the correct sdma interrupts, as well the i2c debug outputs. Does sabresd supports WM8962 as is or do we have to modify things. I'd appreciated the feedback if you had tested this on sabresd recently. Thanks

[fabio_estevam]

Sinan,

You need to run 'alsamixer' and adjust the volume output correctly. The default volume is muted, so you need to change it.

Regards,

Fabio Estevam

[sinanakman]

Hi Fabio

Nice, this did it, thanks. Now I moved on testing arecord. It feels like I have a similar problem. A mute or route issue. I can see the dma and i2c messages but the record produces a silent file. I added amixer sset 'MIXINR IN3R' on  and amixer sset 'INPGAR IN3R' on as well. I actually took a configuration file from a sabresd with FSL 3.0.35-1.1.0 kernel where I tested arecord is working fine and alsactl restore'd it with mainline. I must be still missing something that perhaps old kernel had it hard-wired and I need to add. So is there any other magic setting for a simple arecord/aplay with recent mainline that I have overseen. Thanks

[fabio_estevam]

Hi Sinan,

I don't recall on top of my head, but I think there are two possible sources for the recording that can be selected via alsamixer, so you could try that approach.

I don't have my mx6sl-evk handy to test it.

Regards,

Fabio Estevam

[fabio_estevam]

Besides checking the recording source from alsamixer, please also check the input volume selection as well.

Regards,

Fabio Estevam

[sinanakman]

Hi Fabio, thanks for all your suggestions. I went over this once again. I made sure I included the capture source and turned the capture on. Also I now have PGA input IN1 (L/R) and IN3(L) as well as I set the  MIX  IN to IN3(R). I believe this reflects the page 10 of schematics properly (doc SOURCE:SCH-27516 PDF:SPF-27516). Input Mixer is enabled too. I still don't see anything while trying to record with arecord (except an early click sound). I can send you the config file if you feel like taking a look to see what I might have missed (I don't think I can attach a file here, but I can send you via e-mail).

If you have any other suggestions or happen to be able to give this a try on sabresd board in the near future, I would appreciate it very much.

Thanks

Sinan Akman

[fabio_estevam]

Hi Sinan,

Does it work if you use FSL's 3.10.17 kernel?

I will try to use arecord on my sabresd, but if you don't hear from me, please post report this problem in the linux-arm-kernel and alsa-devel mailing lists.

Regards,

Fabio Estevam

[sinanakman]

Thanks much Fabio. I didn't try FSL 3.10 but will give a try, if not will post in arm-kernel.