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

[Enric Balletbo Serra]

Hi,

2015-05-29 14:16 GMT+02:00 Peter Ujfalusi <peter.ujfalusi at ti.com>:
> 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.
>

Tested with linux-next and same problem here, I also checked with a
scope my clock and it's 12MHz but I need to apply this patch to make
it work.

diff --git a/sound/soc/davinci/davinci-evm.c b/sound/soc/davinci/davinci-evm.c
index 731fb0d..8ce0d32 100644
--- a/sound/soc/davinci/davinci-evm.c
+++ b/sound/soc/davinci/davinci-evm.c
@@ -64,6 +64,11 @@ static int evm_hw_params(struct snd_pcm_substream *substream,
        unsigned sysclk = ((struct snd_soc_card_drvdata_davinci *)
                           snd_soc_card_get_drvdata(soc_card))->sysclk;

+    ret = snd_soc_dai_set_clkdiv(cpu_dai, 0, 2);
+    if (ret < 0)
+            return ret;
+
        /* set the codec system clock */
        ret = snd_soc_dai_set_sysclk(codec_dai, 0, sysclk, SND_SOC_CLOCK_OUT);
        if (ret < 0)

Really odd, so we'll have something different, at the moment I don't
know what could be the difference.


>>
>> 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