[alsa-devel] Audio play problem with tlv320aic3106 in mainline.

[Peter Ujfalusi]

On 05/29/2015 12:24 PM, Enric Balletbo Serra wrote:
>> It might be really 24MHz.
>> If the MCLK in your board is wired like am335x-evmsk or how BeagleBone's audio
>> capes are wired (MCLK is coming from AM335x's EVENT_INTR0/1 pin as CLKOUT1/2)
>> then 24MHz is correct. On the am335x-evm there is a dedicated crystal
>> providing the 12MHz.
>>
> Well, in my board there is also a dedicated crystal providing the
> 12MHz, so I expect that the correct value for clock-frequency is 12MHz
> not 24MHz.

I was wrong with the BBW audio cape.. At least the RevA which I have does have
12MHz crystal connected to aic3106 MCLK, but there is a line to the SoC's
CLKOUT2. By default the codec runs using the 12MHz.
I have checked with a scope and yep, I have 12MHz for MCLK.

> 
>     clocks {
>         compatible = "simple-bus";
>         #address-cells = <1>;
>         #size-cells = <0>;
> 
>         /* audio external oscillator */
>         tlv320aic3x_mclk: oscillator at 0 {
>             compatible = "fixed-clock";
>             #clock-cells = <0>;
>             clock-frequency  = <12000000>;    /* 12MHz */
>         };
>     };
> 
>     sound {
>         compatible = "ti,da830-evm-audio";
>         ti,model = "AM335x-SL50";
>         ti,audio-codec = <&audio_codec>;
>         ti,mcasp-controller = <&mcasp0>;
> 
>         clocks = <&tlv320aic3x_mclk>;
>         clock-names = "mclk";
> 
>         ti,audio-routing =
>             "Headphone Jack",    "HPLOUT",
>             "Headphone Jack",    "HPROUT",
>             "LINE1R",               "Line In",
>             "LINE1L",        "Line In";
>     };

If I use this with my BBW+Audio cape: audio is fine.

> 
> For me it's really odd have to set the clock-frequency to 24MHz to make it work
> 
>             clock-frequency  = <24000000>;

If I change it to this, I will have slow motion playback, as expected.

> For that reason I'm wondering if there is a bug in the driver, did
> anyone test with an am335x-evm board ?

I'm using linux-next.
Not sure what could be the issue.

> 
>>>
>>> [1] https://patchwork.kernel.org/patch/6480071/
>>>
>>> Thanks in advance,
>>> Enric
>>>
>>
>> --
>> Péter
> 
> Thanks,
> Enric
> 


-- 
Péter