On Thu, Jan 15, 2015 at 3:34 PM, Zidan Wang <b50113@xxxxxxxxxxxxx> wrote:
> On Wed, Jan 14, 2015 at 07:27:03PM +0000, Mark Brown wrote:
>> On Wed, Jan 07, 2015 at 03:31:45PM +0800, Zidan Wang wrote:
>>
>> > + for (i = 0; i < ARRAY_SIZE(dac_divs); ++i) {
>> > + if (wm8960->sysclk == lrclk * dac_divs[i]) {
>> > + for (j = 0; j < ARRAY_SIZE(bclk_divs); ++j) {
>> > + if (wm8960->sysclk == wm8960->bclk *
>> > + bclk_divs[j] / 10) {
>> > + goto config_clock;
>> > + }
>> > + }
>> > + }
>> > + }
>> > +
>> > + dev_err(codec->dev, "Unsupported sysclk %d\n", wm8960->sysclk);
>> > + return;
>>
>> It's a bit awkward using the goto like this. A more common way of
>> writing this is to change the above block to be
>>
>> if (i == ARRAY_SIZE(dac_divs))
>> /* return error */
>>
>> rather than skipping over the error. Otherwise this looks good.
>
> Hi Mark,
>
> I found it can't generate bclk for S20_3LE data format.
>
> For 2 channel S20_3LE data format:
>
> bclk = fs * 20 * 2
> Sysclk = BCLKDIV * bclk = BCLKDIV * fs * 40
> Sysclk = DACDIV * fs * 256
>
> BCLKDIV/DACDIV = 256/40 = 32/5
>
> But BCLKDIV/DACDIV can't be 32/5. So I want to support tdm slot.
>
> bclk = fs * slot_width * slots * channal.
>
> Do you think it make sense, or any other ideas?
Reviving this question after two years :).
After "ASoC: codec: wm8960: Relax bit clock computation" patch
https://patchwork.kernel.org/patch/9636769/
we can now support S20_3LE for round rates like 8000, 16000,
32000 and 48000.
But not for 11025, 22050, 441000. Do you think it's worth exploring
"tdm slot" idea? I don't know exactly what it implies.
Another idea, is to completely remove support for S20_3LE since it
is not trivial to derive bitclk from sysclk.
What do you guys think?
Daniel.
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