[RFC PATCH 0/1] platform: x86: tuxi: Implement TUXEDO TUXI ACPI TFAN as thermal subsystem

[Werner Sembach <wse@tuxedocomputers.com>]

Hi,

Following up to https://lore.kernel.org/all/172b7acd-4313-4924-bcbc-41b73b39ada0@tuxedocomputers.com/ and https://lore.kernel.org/all/f26d867e-f247-43bb-a78b-be0bce35c973@roeck-us.net/ I experimented with the thermal subsystem and these are my results so far, but I'm hitting a bit of a wall:

As far as I can tell to implement "2. As long as GTMP is > 80°C fan speed must be at least 30%." I would need to add a new gevenor, lets call it "user_space_with_safeguards". I would be nice when the temp <-> fanspeed relation could be passed via the thermal_trip structure. And safeguarding the hardware from userspace only works when I can restrict userspace from just selecting the preexisting "user_space" govenor.

So my ideas/questions:
- Add a field "min_fanspeed_percent" to the thermal_trip struct that will only be used by the "user_space_with_safeguards" govenor
- Add a "user_space_with_safeguards" govenor that is the same as the "user_space" govenor, but on trip, a minimum speed is applied
- How can i ensure that on further speed updates the min speed is applied to? I could just implement it directly in the cdev, but that would be spagetti coding around the govenor.
- Can I somehow restrict userspace from using certain govenors?
- I'm a litte bit confused about the thermal zone "mode" sysfs switch, here it says deactivate for userspace control: https://elixir.bootlin.com/linux/v6.12/source/Documentation/ABI/testing/sysfs-class-thermal#L20, but what about the user_space govenor then?

Best regards,
Werner

Werner Sembach (1):
  platform: x86: tuxi: Implement TUXEDO TUXI ACPI TFAN as thermal
    subsystem

 drivers/platform/x86/Makefile                 |   3 +
 drivers/platform/x86/tuxedo/Kbuild            |   6 +
 drivers/platform/x86/tuxedo/nbxx/Kbuild       |   8 +
 drivers/platform/x86/tuxedo/nbxx/Kconfig      |   9 +
 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c  |  96 +++++++
 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.h  |  84 ++++++
 .../x86/tuxedo/nbxx/acpi_tuxi_thermal.c       | 241 ++++++++++++++++++
 .../x86/tuxedo/nbxx/acpi_tuxi_thermal.h       |  14 +
 8 files changed, 461 insertions(+)
 create mode 100644 drivers/platform/x86/tuxedo/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/Kconfig
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.h
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi_thermal.c
 create mode 100644 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi_thermal.h

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2.43.0