[alsa-devel] [PATCH 2/3] ASoC: Intel: kbl_da7219_max98357a_rt5660: Add a new codec rt5660

[Hui Wang]

On 2018/12/6 下午11:08, Pierre-Louis Bossart wrote:
> On 12/6/18 8:52 AM, Hui Wang wrote:
>> The new Dell IoT platform uses kabylake + alc3277 codec, and alc3277
>> shares the driver with the codec rt5660, here we choose the
>> closest machine driver kbl_da7219_max98357a, and based on this driver,
>> we add a new codec rt5660 to it.
>>
>> The audio design on this IoT platform is as below:
>>   - Intel kabylake platform
>>   - connect the codec ALC3277 via SSP0
>>   - line-out and line-in with Micbias jacks
>>   - line-out mute control and jack detection of line-out and line-in
>>   - two HDMI ports with audio capability
>
> I am not sure it makes sense to stuff the rt5660 support in a machine 
> driver that's meant mostly for Chromebooks, and I am not sure why you 
> picked this one specifically.

Since this is a kabylake platform, we have 4 candidates to choose if we 
want to stuff the code into an existing machine driver, they are:

kbl_da7219_max98357a.c  kbl_da7219_max98927.c kbl_rt5663_max98927.c  
kbl_rt5663_rt5514_max98927.c

kbl_da7219_max98927.c: it connects 2 codecs via SSP0, so we can't share 
the ssp0_hw_params and ssp_fixup functions with this Dell IoT design

kbl_rt5663_max98927.c:  it connects 2 codes via SSP0, and the rt5663 is 
connected to SSP1,  we can't share the ssp0_hw_params and ssp_fixup 
functions with this Dell IoT design, more over, it requires the clock of 
"ssp1_mclk" and "ssp1_sclk" which is not needed on Dell IoT.

kbl_rt5663_rt5514_max98927.c:  nearly same as kbl_rt5663_max98927.c

So in order to share the existing code with Dell IoT maximumly, I choose 
kbl_da7219_max98357a.c, it connects 1 codec via SSP0 with 
SND_SOC_DAIFMT_I2S_B, this is same as the Dell IoT's design.


> Since there is no reuse of the DA7219, DMIC or MAX98357a, I would 
> argue that you want to define a new machine driver so that you only 
> select and compile in what you need, not to mention that it'll be 
> easier to maintain, both for upstream and for Chrome backports.

Yes, a standalone driver for a specific HW is easy to maintain, but it 
will add lots of copy-and-paste code. If it is really not good to stuff 
Dell IoT into an existing machine driver, I will prepare a standalone 
machine driver for it in the V2.


Thanks for reviewing, and expect your comment and direction.

Regards,

Hui.

> Thanks!
> -Pierre
>
>>
>> Signed-off-by: Hui Wang <hui.wang at canonical.com>
>> ---
>>   sound/soc/intel/boards/Kconfig                |   7 +-
>>   sound/soc/intel/boards/Makefile               |   4 +-