Introduce driver for the ThinkPad T14s Gen6 Snapdragon EC. In theory
it seems to be compatible with the ThinkPad ACPI driver, but these
devices are booted with device tree. As the name implies, the existing
ThinkPad ACPI driver only supports the ACPI interface. Looking at
the implementation, the ACPI DSDT contains many mapping functions
to translate the low level I2C messages into the interface used by
the ThinkPad ACPI driver. Adding DT support to the ThinkPad ACPI driver
would require adding all those translation functions, which would add
more or less the same amount of code as writing a separate driver using
the low level interface directly. I don't think it's sensible to make
the existing ACPI driver even more complicated, so I went for a separate
driver.

I managed to get system LEDs, audio LEDs, extra keys and the keyboard
backlight control working. The EC also seems to be used for some thermal
bits, which I haven't looked into deeply. As far as I understand most
thermal and fan control is handled by a different controller
(0x36@i2c5) anyways.

Apart from that the EC is involved in proper system suspend, which
is something I do not yet understand (I don't have any documentation
apart from the dis-assembled DSDT and existing ACPI driver). Right
now I disabled wake capabilities for the IRQ, since it would wake
up the system when closing the LID. Hopefully a way to mask specific
events will be found in the future.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
Sebastian Reichel (3):
      dt-bindings: platform: Add Lenovo Thinkpad T14s EC
      platform: arm64: thinkpad-t14s-ec: new driver
      arm64: dts: qcom: x1e80100-t14s: add EC

 .../bindings/platform/lenovo,thinkpad-t14s-ec.yaml |  49 ++
 MAINTAINERS                                        |   6 +
 .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    |  23 +
 drivers/platform/arm64/Kconfig                     |  20 +
 drivers/platform/arm64/Makefile                    |   1 +
 drivers/platform/arm64/lenovo-thinkpad-t14s.c      | 597 +++++++++++++++++++++
 6 files changed, 696 insertions(+)
---
base-commit: c8bc81a52d5a2ac2e4b257ae123677cf94112755
change-id: 20250831-thinkpad-t14s-ec-ddeb23dbdafb

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>

On Sun, 31 Aug 2025 23:28:30 +0200, Sebastian Reichel wrote:
> Introduce driver for the ThinkPad T14s Gen6 Snapdragon EC. In theory
> it seems to be compatible with the ThinkPad ACPI driver, but these
> devices are booted with device tree. As the name implies, the existing
> ThinkPad ACPI driver only supports the ACPI interface. Looking at
> the implementation, the ACPI DSDT contains many mapping functions
> to translate the low level I2C messages into the interface used by
> the ThinkPad ACPI driver. Adding DT support to the ThinkPad ACPI driver
> would require adding all those translation functions, which would add
> more or less the same amount of code as writing a separate driver using
> the low level interface directly. I don't think it's sensible to make
> the existing ACPI driver even more complicated, so I went for a separate
> driver.
> 
> I managed to get system LEDs, audio LEDs, extra keys and the keyboard
> backlight control working. The EC also seems to be used for some thermal
> bits, which I haven't looked into deeply. As far as I understand most
> thermal and fan control is handled by a different controller
> (0x36@i2c5) anyways.
> 
> Apart from that the EC is involved in proper system suspend, which
> is something I do not yet understand (I don't have any documentation
> apart from the dis-assembled DSDT and existing ACPI driver). Right
> now I disabled wake capabilities for the IRQ, since it would wake
> up the system when closing the LID. Hopefully a way to mask specific
> events will be found in the future.
> 
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
> Sebastian Reichel (3):
>       dt-bindings: platform: Add Lenovo Thinkpad T14s EC
>       platform: arm64: thinkpad-t14s-ec: new driver
>       arm64: dts: qcom: x1e80100-t14s: add EC
> 
>  .../bindings/platform/lenovo,thinkpad-t14s-ec.yaml |  49 ++
>  MAINTAINERS                                        |   6 +
>  .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    |  23 +
>  drivers/platform/arm64/Kconfig                     |  20 +
>  drivers/platform/arm64/Makefile                    |   1 +
>  drivers/platform/arm64/lenovo-thinkpad-t14s.c      | 597 +++++++++++++++++++++
>  6 files changed, 696 insertions(+)
> ---
> base-commit: c8bc81a52d5a2ac2e4b257ae123677cf94112755
> change-id: 20250831-thinkpad-t14s-ec-ddeb23dbdafb
> 
> Best regards,
> --
> Sebastian Reichel <sebastian.reichel@collabora.com>
> 
> 
> 


My bot found new DTB warnings on the .dts files added or changed in this
series.

Some warnings may be from an existing SoC .dtsi. Or perhaps the warnings
are fixed by another series. Ultimately, it is up to the platform
maintainer whether these warnings are acceptable or not. No need to reply
unless the platform maintainer has comments.

If you already ran DT checks and didn't see these error(s), then
make sure dt-schema is up to date:

  pip3 install dtschema --upgrade


This patch series was applied (using b4) to base:
 Base: using specified base-commit c8bc81a52d5a2ac2e4b257ae123677cf94112755

If this is not the correct base, please add 'base-commit' tag
(or use b4 which does this automatically)

New warnings running 'make CHECK_DTBS=y for arch/arm64/boot/dts/qcom/' for 20250831-thinkpad-t14s-ec-v1-0-6e06a07afe0f@collabora.com:

arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s-oled.dtb: ec@28 (lenovo,thinkpad-t14s-ec): 'wakeup-source' does not match any of the regexes: '^pinctrl-[0-9]+$'
	from schema $id: http://devicetree.org/schemas/platform/lenovo,thinkpad-t14s-ec.yaml#
arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtb: ec@28 (lenovo,thinkpad-t14s-ec): 'wakeup-source' does not match any of the regexes: '^pinctrl-[0-9]+$'
	from schema $id: http://devicetree.org/schemas/platform/lenovo,thinkpad-t14s-ec.yaml#

On 31/08/2025 23:28, Sebastian Reichel wrote:
> Introduce driver for the ThinkPad T14s Gen6 Snapdragon EC. In theory
> it seems to be compatible with the ThinkPad ACPI driver, but these
> devices are booted with device tree. As the name implies, the existing
> ThinkPad ACPI driver only supports the ACPI interface. Looking at
> the implementation, the ACPI DSDT contains many mapping functions
> to translate the low level I2C messages into the interface used by
> the ThinkPad ACPI driver. Adding DT support to the ThinkPad ACPI driver
> would require adding all those translation functions, which would add
> more or less the same amount of code as writing a separate driver using
> the low level interface directly. I don't think it's sensible to make
> the existing ACPI driver even more complicated, so I went for a separate
> driver.
> 
> I managed to get system LEDs, audio LEDs, extra keys and the keyboard
> backlight control working. The EC also seems to be used for some thermal
> bits, which I haven't looked into deeply. As far as I understand most
> thermal and fan control is handled by a different controller
> (0x36@i2c5) anyways.
> 
> Apart from that the EC is involved in proper system suspend, which
> is something I do not yet understand (I don't have any documentation
> apart from the dis-assembled DSDT and existing ACPI driver). Right
> now I disabled wake capabilities for the IRQ, since it would wake
> up the system when closing the LID. Hopefully a way to mask specific
> events will be found in the future.
> 
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
> Sebastian Reichel (3):
>        dt-bindings: platform: Add Lenovo Thinkpad T14s EC
>        platform: arm64: thinkpad-t14s-ec: new driver
>        arm64: dts: qcom: x1e80100-t14s: add EC
> 
>   .../bindings/platform/lenovo,thinkpad-t14s-ec.yaml |  49 ++
>   MAINTAINERS                                        |   6 +
>   .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    |  23 +
>   drivers/platform/arm64/Kconfig                     |  20 +
>   drivers/platform/arm64/Makefile                    |   1 +
>   drivers/platform/arm64/lenovo-thinkpad-t14s.c      | 597 +++++++++++++++++++++
>   6 files changed, 696 insertions(+)
> ---
> base-commit: c8bc81a52d5a2ac2e4b257ae123677cf94112755
> change-id: 20250831-thinkpad-t14s-ec-ddeb23dbdafb
> 
> Best regards,

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED

All worked :-)

Thanks !

Neil