platform/x86: toshiba_acpi: Add fan RPM reading (internals)
authorArvid Norlander <lkml@vorpal.se>
Fri, 2 Sep 2022 17:40:17 +0000 (19:40 +0200)
committerHans de Goede <hdegoede@redhat.com>
Fri, 9 Sep 2022 15:43:05 +0000 (17:43 +0200)
commitdd193dcdc9c02ee28ca0490d737d7a0636332569
tree3ea413c4d4f64388f561d91c5802ff9647a90116
parentdb55fb8a06f241e168a4f275970f2701d52040c6
platform/x86: toshiba_acpi: Add fan RPM reading (internals)

This add the internal feature detection and reading function for fan RPM.

The approach is based on tracing ACPI calls using AMLI (a tracer/debugger
built into ACPI.sys) while using the Windows cooling self-test software.

The call used is {HCI_GET, 0x45, 0, 1, 0, 0} which returns:
{0x0, 0x45, fan_rpm, probably_max_rpm, 0x0, 0x0}

What is probably the max RPM is not currently used.

Signed-off-by: Arvid Norlander <lkml@vorpal.se>
Link: https://lore.kernel.org/r/20220902174018.1720029-2-lkml@vorpal.se
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
drivers/platform/x86/toshiba_acpi.c