[PATCH 0/3] platform: arm64: lenovo-thinkpad-t14s: Add support for the Gen 7 EC

[Abel Vesa]

The Lenovo ThinkPad T14s Gen 7 (Snapdragon X2, Mahua) has an embedded
controller at the same I2C address as the Gen 6 one, with the same
register layout and event codes, but it speaks a different command
protocol over I2C. With the existing driver the EC never reports any
event and the LED and keyboard backlight writes have no effect.

The Gen 7 protocol is taken from the ACPI EC accessors in the Gen 7
firmware (RDEC, WREC and QEVT): reads, writes and event reads use the
0x80, 0x81 and 0x84 commands. The firmware also describes the EC
interrupt as edge triggered, active low.

Patch 1 adds a Gen 7 compatible to the binding, patch 2 adds the Gen 7
variant to the driver and patch 3 describes the EC on the T14s Gen 7.

Tested on a ThinkPad T14s Gen 7 (LCD): Fn+F4 reports KEY_MICMUTE, the
mic mute and lid logo LEDs (including the hardware blinking) and the
keyboard backlight work, and Fn+Space changes are reported through the
LED class.

Prepared with help from an LLM-based assistant.

---
Abel Vesa (3):
      dt-bindings: embedded-controller: lenovo,thinkpad-t14s-ec: Add Gen 7 support
      platform: arm64: lenovo-thinkpad-t14s: Add Gen 7 EC support
      arm64: dts: qcom: mahua-lenovo-thinkpad-t14s-gen7: Describe the Embedded Controller

 .../lenovo,thinkpad-t14s-ec.yaml                   |   4 +-
 .../qcom/mahua-lenovo-thinkpad-t14s-gen7-lcd.dts   |  24 +++
 drivers/platform/arm64/lenovo-thinkpad-t14s.c      | 176 +++++++++++++++++++--
 3 files changed, 193 insertions(+), 11 deletions(-)
---
base-commit: ddfe51b0a0f5dc9e415cc2c8ad8db17532dd426b
change-id: 20261106-t14s-gen7-ec-297593bda0fc

Best regards,
--  

Abel