[PATCH v5 0/3] Input: support for STM FTS5

[David Heidelberg via B4 Relay]

Used on various phones. Minimal viable driver.

Includes device-tree enabling touchscreen on Pixel 3.

What is missing:
 - switching between AP and SLPI mode (to be able to wake up phone by touch)
 - firmware loading
 - anything above basic touch

Signed-off-by: David Heidelberg <david@xxxxxxx>
---
Changes in v5:
- 3.3V is analog, 1.8V is digital supply. Fix that.
- Name the error variables "err" (Dmitry)
- Use scoped_guard() for ->running, and only set it once the scan
  mode has actually been enabled. (Dmitry)
- Use i2c_master_send() instead of open-coding a single-message
  i2c_transfer(). (Dmitry)
- Drivers may report coordinates outside the declared min/max, so
  remove the clamping. (Dmitry)
- BTN_TOUCH and INPUT_PROP_DIRECT are already set up by
  input_mt_init_slots(..., INPUT_MT_DIRECT). (Dmitry)
- Let the input core track contacts: drop the touch_id/stylus_id
  bitmaps and the hand-rolled BTN_TOUCH reporting, and sync the frame
  once per interrupt with input_mt_sync_frame() instead of calling
  input_sync() per contact event. The controller pushes contacts one
  by one into the event FIFO and only resends the ones that changed,
  so INPUT_MT_DROP_UNUSED is wrong here and is dropped as well. (Dmitry)
- Restore the FTS4 interrupts accidentally dropped by introduction of
  FTS5.
- mode-switch-gpios isn't required with stmfts5. Some designs, such as
  Xiaomi Mi 8, has no such GPIO connected and is limited to AP mode.
- Nit: updated example to use interrupts-extended.
- Nit: (maximum x/y coordinate reported + 1), corrected example.
- Link to v4: https://lore.kernel.org/r/20260409-stmfts5-v4-0-64fe62027db5@xxxxxxx

Changes in v4:
- Wrap everything below enabling the supplies into stmfts_configure()
  to avoid bunch of gotos to power off on error (Dmitry T.)
- Finished chip specific ops and removed is_fts5. (Dmitry T.)
- Link to v3: https://lore.kernel.org/r/20260403-stmfts5-v3-0-5da768cfd201@xxxxxxx

Changes in v3:
- s/touchscreen_pins/touchscreen_irq_n. (Konrad)
- Use interrupts-extended. (Konrad)
- Fixed rebase conflict against 8665ceb926ec ("Input: stmfts - use guard notation when acquiring mutex")
- Rename switch-gpios to mode-switch-gpios.
- Do not define properties in if:then: branches. (Krzysztof)
- Link to v2: https://lore.kernel.org/r/20260315-stmfts5-v2-0-70bc83ee9591@xxxxxxx

Changes in v2:
- Fix typo in the binding s/switch-gpio/switch-gpios/.
- Deduplacate allOf. (Rob yamllint)
- Add missing S-off-by. (Dmitry B.)
- Dropped irq-gpios as it's not needed. (Konrad)
- Correct x and y touchscreen area size. (Konrad)
- Correct reset introduction commit description. (Krzysztof)
- Partially implemented chip specific ops. (Dmitry T.)
- Separeted license naming cleanup into separate commit (Dmitry T.)
- Link to v1: https://lore.kernel.org/r/20260301-stmfts5-v1-0-22c458b9ac68@xxxxxxx

---
David Heidelberg (2):
      dt-bindings: input: touchscreen: st,stmfts: Introduce STM FTS5
      Input: stmfts - support FTS5

Petr Hodina (1):
      arm64: dts: qcom: sdm845-google: Add STM FTS touchscreen support

 .../bindings/input/touchscreen/st,stmfts.yaml      |  29 +-
 .../arm64/boot/dts/qcom/sdm845-google-blueline.dts |  19 +-
 arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi |   2 +-
 drivers/input/touchscreen/stmfts.c                 | 430 +++++++++++++++++++--
 4 files changed, 436 insertions(+), 44 deletions(-)
---
base-commit: 95d6a9ccef99117115e41e9adb271243bd5e985b
change-id: 20260214-stmfts5-b47311fbd732

Best regards,
--  
David Heidelberg <david@xxxxxxx>