The ROCK 4D uses an ADC input to distinguish between a headphone (i.e.,
no mic) and a headset (i.e., with mic). After some searching, it appears
that the closest we can get to modelling this is by sending a particular
switch input event.

So this series modifies the adc-keys bindings, extends the adc-keys
driver to allow sending other input types as well, and then adds the
analog audio nodes to ROCK 4D's device tree.

It should be noted that analog capture from the TRRS jack currently
results in completely digitally silent audio for me, i.e. no data other
than 0xFF. There's a few reasons why this could happen, chief among them
that my SAI driver is broken or that the ES8328 codec driver is once
again broken. The DAPM routes when graphed out look fine though. So the
DTS part is correct, and I can fix the broken capture in a separate
follow-up patch that doesn't have to include DT people.

Another possibility is that my phone headset, despite being 4 rings and
having a little pin hole at the back of the volume doodad, does not
actually have a microphone, but in that case I'd still expect some noise
in the PCM. Maybe it's just shy.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
Changes in v2:
- Drop HDMI audio patch, as it was already merged.
- adc-keys: rename "keycode" to "code".
- adc-keys: make the keycode (now "code") local a u32 instead of an int
- adc-keys: only allow EV_KEY and EV_SW for now. Rename patch
  accordingly.
- adc-keys: Add another patch to rework probe function error logging.
- Link to v1: https://lore.kernel.org/r/20250630-rock4d-audio-v1-0-0b3c8e8fda9c@collabora.com

---
Nicolas Frattaroli (4):
      dt-bindings: input: adc-keys: allow linux,input-type property
      Input: adc-keys - support EV_SW as well, not just EV_KEY.
      Input: adc-keys - Use dev_err_probe in probe function
      arm64: dts: rockchip: add analog audio to ROCK 4D

 .../devicetree/bindings/input/adc-keys.yaml        |  3 +
 arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts    | 90 ++++++++++++++++++++++
 drivers/input/keyboard/adc-keys.c                  | 88 ++++++++++-----------
 3 files changed, 138 insertions(+), 43 deletions(-)
---
base-commit: 3e7f562e20ee87a25e104ef4fce557d39d62fa85
change-id: 20250627-rock4d-audio-cfc07f168a08

Best regards,
-- 
Nicolas Frattaroli <nicolas.frattaroli@collabora.com>