[PATCH v8 0/5] Input: support for STM FTS5

[David Heidelberg via B4 Relay <devnull+david.ixit.cz@kernel.org>]

Used on various phones. Minimal viable driver.

Includes device-tree enabling touchscreen on Pixel 3.
Also, tested on Xiaomi Mi 8 (device-tree is not yet inside the mainline).

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@ixit.cz>
---
Changes in v8:
- Split DT binding example changes into own commit (Krzysztof, Dmitry)
- Refectored the stmfts_power_on fix. (Dmitry)
- Added ABS_MT_TOOL_TYPE. (Dmitry, Sashiko)
- Link to v7: https://patch.msgid.link/20260907-stmfts5-v7-0-4a53381cd038@ixit.cz

Changes in v7:
- Added 'Input: stmfts - wait for controller ready after reset',
  the waiting is done for both FTS4 and FTS5, similarly to the
  downstream driver. Should improve reliability everywhere.
- Link to v6: https://patch.msgid.link/20260906-stmfts5-v6-0-50fbf6af8718@ixit.cz

Changes in v6:
- Enable only the multi-touch scan on FTS5 sense-on (0xff was wrong,
  only 0x01 is needed. This broke Xiaomi Mi 8 toucschreen).
- Fixed Y-coordinate comments. (Dmitry)
- Corrected event[0] parsing. (Dmitry)
- Dropped checking < 0 on unsigned area. (Dmitry)
- Dropped unnecessary i2c writes after reset. Verified against
  downstream driver. (Dmitry, Sashiko)
- Added pieces for supporting non-OF integration. (Sashiko)
- Shared input open/close into one impl. (Dmitry).
- Link to v5: https://patch.msgid.link/20260810-stmfts5-v5-0-0c737d929976@ixit.cz

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@ixit.cz

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@ixit.cz

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@ixit.cz

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@ixit.cz

To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Maxime Coquelin <mcoquelin.stm32@gmail.com>
To: Alexandre Torgue <alexandre.torgue@foss.st.com>
To: Petr Hodina <petr.hodina@protonmail.com>
To: David Heidelberg <david@ixit.cz>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Henrik Rydberg <rydberg@bitmath.org>
To: Bjorn Andersson <andersson@kernel.org>
To: Konrad Dybcio <konradybcio@kernel.org>
Cc: linux-input@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org

---
David Heidelberg (4):
      Input: stmfts - wait for controller ready after reset
      dt-bindings: input: touchscreen: st,stmfts: Improve example
      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                 | 462 ++++++++++++++++++---
 4 files changed, 443 insertions(+), 69 deletions(-)
---
base-commit: 944a035ecca915ae947905dcfb03f2b9dc6d032c
change-id: 20260214-stmfts5-b47311fbd732

Best regards,
--  
David Heidelberg <david@ixit.cz>