[alsa-devel] [PATCH] ASoC: rt1011: export r0 and temperature config

[Mark Brown]

On Tue, Oct 08, 2019 at 07:22:17PM +0800, Cheng-yi Chiang wrote:

> The VPD is not part of the codec.
> It is a binary blob in system firmware where we can store important
> information per-device.
> The calibration data is written to RO section of VPD in the factory
> during calibration step.

Ugh, this is not idiomatic for a DT system :(

> The codec driver is not suitable of reading this information directly
> because the string format written into VPD is customized per board.
> For example on cml_rt1011_rt5682.c there are four R0 values for four

The expected model for a DT system is that this stuff should just come
in through DT properties, if for system design/manufacturing reasons it
needs to be stored separately then you'd expect it to be merged into the
main DT by the bootloader or something else earlier on in boot.

> speakers, and one temperature values . So in this case, there are
> totally 5 values in a VPD dsm_calib key. In VPD, the format is like
> "dsm_calib"="0x00278F09 0x00251E1B 0x0021AFE6 0x0022720A 0x0000012E"
> We put all the information into one string to allow arbitrary
> calibration data needed for smart amp calibration in the future.
> On other system using smart amp, there might be two speakers, with two
> temperature values..etc. The format will be changed accordingly.
> Number of temperature values depends on number of temperature sensor
> available near the speakers.
> Since machine driver knows the combination of speakers and the
> available temperature sensor, we think that machine driver is the
> better place to put this per-board logic.

I'm not sure why they all need to be in one property?  That's a
secondary problem though.
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