[alsa-devel] [PATCH 1/2] ASoC: rockchip: i2s: add 8 channels capture and lrck-mode support

Caleb Crome caleb at crome.org
Wed Oct 7 06:04:51 PDT 2015

Hi sugar,
   Can the rockchip support more than 8 channels?  Ideally, we would like to capture 16 channels and playback 16 channels simultaneously.  

Thanks,  Caleb 

Sent from my iPhone

> On Oct 7, 2015, at 1:01 AM, sugar <sugar.zhang at rock-chips.com> wrote:
> Sorry for late reply, we were in the National Day Holiday.
>> 在 10/1/2015 02:46, Mark Brown 写道:
>>> On Mon, Sep 28, 2015 at 04:16:12PM +0800, sugar wrote:
>>> 在 9/24/2015 00:24, Mark Brown 写道:
>>>> My initial thought here is that the machine driver should be responsible
>>>> for setting this and then the DAI driver should check to see if
>>>> symmetric_rates are in use and configure itself appropriately.  Is there
>>>> a reason why this won't work here?
>>> It's for i2s ip configuration, in the most situation, there is no need
>>> to use this property, except one case:
>>> In order to save gpio pins for other function use, we may use single
>>> lrck(tx or rx) pin. of course, it depends on product design. when in i2s
>>> slave mode, we need to configure this to share lrck with tx/rx inside i2s
>>> logic.
>>> symmetric_rates flag works fine on rockchip platform, but it can't cover the
>>> above case.
>>> Do you have any suggestion about this or maybe there is no need to upstream
>>> this special part?
>> What makes you say that the symmetric_rates flag can't be used to cover
>> this case?  What you describe above is hte normal reason for needing to
>> enforce symmetric_rates.  The driver should be able to check if the flag
>> has been set just as well as the core is.
> Got it, How about the following modify?
> if (dai->symmetric_rates)
>    regmap_update_bits(i2s->regmap, I2S_CKR,
>                           I2S_CKR_TRCM_MASK,
>                           I2S_CKR_TRCM(val));
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