Re: [RFC PATCH 01/34] ASoC: dt-bindings: Add a separate compatible for the A64 codec

From: Samuel Holland
Date: Mon Feb 17 2020 - 22:17:54 EST

On 2/17/20 3:49 AM, Chen-Yu Tsai wrote:
> On Mon, Feb 17, 2020 at 2:42 PM Samuel Holland <samuel@xxxxxxxxxxxx> wrote:
>> The digital codec in the A64 is largely compatible with the one in the
>> A33, with two changes:
>> - It is missing some muxing options for AIF1/2/3 (not currently
>> supported by the driver)
> Is this at the pinctrl level or mixer level? If it's at the pinctrl level
> then it's out of the scope of this driver/binding. It could very well have
> those signals, just that they aren't routed outside the SoC.

This is in reference to the muxes shown at the top of the A33 diagram, above the
I2S/PCM interfaces. These appear to map to bits 0-6 of AIF3_SGP_CTRL, which are
marked as reserved on the A64 and the AC100.

Comparing the three datasheets in a bit more detail (but by no means exhaustively):
- The A64 has a second DRC block, unlike the A33 and AC100.
- The jack detection registers (0x310-0x318) are present on the A64
and AC100, but undocumented/missing on the A33.

So there are enough differences to warrant a new compatible, but since none of
the unique functionality is used by the driver (even after this series), a
fallback should work.