[alsa-devel] CherryTrail SST firmware limitations query

[Vinod Koul]

On Thu, Jan 21, 2016 at 11:10:50PM +0000, Dan O'Donovan wrote:
> (Sorry, re-sending as I wasn't subscribed to the alsa-devel mailing
> list on my previous attempt)
> 
> Hi Vinod
> 
> I am currently attempting to use the SSP0 port on an Intel X5-Z8300
> SoC (Cherry Trail) with a new codec.
> 
> I have seen that you have committed SST firmware 'fw_sst_22a8.bin'
> and related SST audio soc drivers in the past, so I hope you don't
> mind if I ask you some questions about it here.
> 
> Primarily, I am wondering if there are any limitations imposed by
> that firmware binary that I need to be aware of. I haven't been able
> to find much information about what this firmware does or doesn't
> support.

That binary is not for CHT. Each Bin is specfic to a platform. I have
the BYT and BSW versions, but not CHT

> 
> For example, existing CHT SST machine drivers suggest that the PCM
> bit clock is fixed at 19.2MHz.

Yes, the MCLK will be 19.2 here

> Also, I am wondering if all SSP ports on the SoC are supported by
> that firmware, or if it is limited to just SSP2?

SSP2, for SSP0 we need to get a new version

> Are there any other limitations that I may need to be aware of in
> the firmware (or in the SSP back-end driver) when attempting to
> connect a new codec (TI PCM5122 initially) to SSP0.

Bigger pole will be getting the firmware. Usually we support I2S and TDM
modes

HTH
-- 
~Vinod