Re: [PATCH v3 17/20] ASoC: dt-bindings: tas2770: add flags for SDOUT pulldown and zero-fill

[James Calligeros]

On Tue, Mar 4, 2025 at 1:50 PM Rob Herring <robh@xxxxxxxxxx> wrote:
> Can't you align this with the other property you added? Or extend the
> existing TDM properties we have.

I don't think either option makes sense given the functionality. This chip
behaves differently to TAS2764, and instead of using a bitmask to determine
which slots to ignore, we only get a single bit to tell the chip whether we want
it to fill or pull down *all* inactive slots. The property being a u32 mask
therefore does not make sense here.

Building the logic off the existing generic TDM slot properties would alter
behaviour of existing implementations where zero-fill and pulldown may not be
required or even wanted. This may continue to be the case going forward so I'd
rather make it an explicit opt-in rather than some unconditional thing we try to
turn on heuristically.

I gave some thought to flipping these bits if a TDM slot mask is passed to the
driver, however it can still be the case that we don't want both zero-fill *and*
pulldown active at the same time, or as above some implementations may want
neither, so we still need to be able to specify them individually.

Regards,
James