[PATCH v2 0/3] Add Nsiway NS2009 touchscreen support

[Miotsuki Mizuno <founder@crepuse.com>]

Add the Nsiway vendor prefix, an NS2009 hardware binding and an initial
polling driver for the four-wire resistive touchscreen controller.

Changes in v2:
- Address Dmitry Torokhov's review by describing NS2009 hardware
  capabilities independently of the initial polling implementation.
- Add optional interrupts, wakeup-source, vdd-supply and vref-supply.
- Allow touchscreen-x-plate-ohms, touchscreen-max-pressure and
  touchscreen-fuzz-pressure via the common touchscreen schema.
- Add a second example showing an active-low pen interrupt and supplies;
  retain the no-interrupt example.

The driver and vendor-prefix changes are unchanged from v1. IRQ-based
operation, wakeup handling and Z1/Z2 touch resistance calculation will
be implemented separately. These features are not claimed to work in
the current polling driver. The existing raw Z1 minimum contact threshold
is unchanged, including the tested M10 value of 150.

Validation:
- dt_binding_check for both NS2009 examples: PASS.
- M10 DTS rebuild and CHECK_DTBS=y: PASS.
- Full-schema direct validation of the rebuilt combined M10 DTB and
  the existing independent touchscreen DTB: PASS, no diagnostics.
- The combined DTB is byte-identical to the previously hardware-tested
  DTB. No new runtime IRQ or pressure test was performed.
NS2009 dependencies are imported only in the independent M10 validation
branch; no claim that they are merged.

Mizuno Miotsuki (3):
  dt-bindings: vendor-prefixes: add Nsiway
  dt-bindings: input: touchscreen: add Nsiway NS2009
  Input: add Nsiway NS2009 resistive touchscreen driver

 .../input/touchscreen/nsiway,ns2009.yaml      | 104 +++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   7 +
 drivers/input/touchscreen/Kconfig             |  10 +
 drivers/input/touchscreen/Makefile            |   1 +
 drivers/input/touchscreen/ns2009.c            | 175 ++++++++++++++++++
 6 files changed, 299 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/nsiway,ns2009.yaml
 create mode 100644 drivers/input/touchscreen/ns2009.c


base-commit: af32da41b0327b9c6a37856ba82b6760d6c8d10e
-- 
2.56.0