[PATCH RFC 0/3] Input: add initial support for Goodix GTX8 touchscreen ICs

[Jens Reidel <adrian@mainlining.org>]

These ICs support SPI and I2C interfaces, up to 10 finger touch, stylus
and gesture events.

This driver is derived from the Goodix gtx8_driver_linux available at
[1] and only supports the GT9886 and GT9896 ICs present in the Xiaomi
Mi 9T and Xiaomi Redmi Note 10 Pro smartphones.

The current implementation only supports Normandy and Yellowstone type
ICs, aka only GT9886 and GT9896. It is also limited to I2C only, since I
don't have a device with GTX8 over SPI at hand. Adding support for SPI
should be fairly easy in the future, since the code uses a regmap.

Support for advanced features like:
- Firmware updates
- Stylus events
- Gesture events
- Nanjing IC support
is not included in current version.

The current support requires a previously flashed firmware to be
present.

As I did not have access to datasheets for these ICs, I extracted the
addresses from a couple of config files using a small tool [2]. The
addresses are identical for the same IC families in all configs I
observed, however not all of them make sense and I stubbed out firmware
request support due to this.

[1] https://github.com/goodix/gtx8_driver_linux
[2] https://github.com/sm7150-mainline/goodix-cfg-bin

Signed-off-by: Jens Reidel <adrian@mainlining.org>
---
Jens Reidel (3):
      dt-bindings: input: document Goodix GTX8 Touchscreen ICs
      Input: add support for Goodix GTX8 Touchscreen ICs
      MAINTAINERS: add an entry for Goodix GTX8 Touchscreen driver

 .../bindings/input/touchscreen/goodix,gt9886.yaml  |  71 +++
 MAINTAINERS                                        |   7 +
 drivers/input/touchscreen/Kconfig                  |  15 +
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/goodix_gtx8.c            | 562 +++++++++++++++++++++
 drivers/input/touchscreen/goodix_gtx8.h            | 137 +++++
 6 files changed, 793 insertions(+)
---
base-commit: ae2d20002576d2893ecaff25db3d7ef9190ac0b6
change-id: 20250918-gtx8-59a50ccd78a5

Best regards,
-- 
Jens Reidel <adrian@mainlining.org>