[alsa-devel] [RFC PATCH] ASoC: wm8741: Allow master clock switching

[Sergej Sawazki]

On 2015-06-05 at 05:22PM, Charles Keepax wrote:
>
> I think rather than removing the constraints entirely here,
> perhaps just don't set any constraints if there is no SYSCLK yet.
> That way we get the benefits of the constraints for single clock
> systems (such as user-space being able to arrange appropriate
> software resampling) but those like yours can configure the clock
> later.
>

Good point, I will add it to v2.

>> +	if (!wm8741->sysclk) {
>> +		dev_err(codec->dev,
>> +			"No MCLK configured, call set_sysclk() on hw_params\n");
>> +		return -EINVAL;
>> +	}
>
> Then you can keep this error check here and fail if we reach
> hw_params and still don't have a SYSCLK. You will probably need
> to provide a way to clear the SYSCLK though set_dai_sysclk as
> well.

Is snd_soc_dai_set_sysclk( , , 0, ) the right way to clear the SYSCLK?

Thanks,
Sergej