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

[Enric Balletbo Serra]

Thanks for the answer Peter,

2015-05-29 9:20 GMT+02:00 Peter Ujfalusi <peter.ujfalusi at ti.com>:
> On 05/28/2015 02:36 PM, Enric Balletbo Serra wrote:
>> Dear all,
>>
>> Recently I sent some patches to add support for a new board based on
>> AM335x processor [1]. The board has the TLV320AIC3106 audio codec, the
>> MCLK signal is provided by an external oscillator of 12MHz. The
>> problem is that when I play a wav file for example I heard the song a
>> double speed. This is with v4.0 and current mainline.
>>
>> In dts file I defined "ti,codec-clock-rate = <12000000>;" which is the
>> correct value. Curiously when I changed the clock rate value to
>> 24000000 I heard the song at normal speed. AFAIK the correct value for
>> clock-rate is 12MHz so I suspect that something is wrong in the
>> driver, maybe it sets a wrong clock divider/multiplier ? Anyone can
>> point me in the right direction to fix the issue ? I see that
>> am335x-evm and am335x-pepper boards also uses this audio codec, did
>> anyone with those boards have the same problem?
>
> 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.

    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";
    };

For me it's really odd have to set the clock-frequency to 24MHz to make it work

            clock-frequency  = <24000000>;

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

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

Thanks,
Enric