platform/x86: thinkpad_acpi: Add ThinkPad PrivacyGuard
authorAlexander Schremmer <alex@alexanderweb.de>
Thu, 22 Aug 2019 11:48:33 +0000 (13:48 +0200)
committerAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Sat, 7 Sep 2019 18:16:09 +0000 (21:16 +0300)
commit110ea1d833ad291272d52e0a40a06157a3d9ba17
tree3acdf105f4d3b4d0b076092f3028f130d8cd3042
parentad0d315b4d4e7138f43acf03308192ec00e9614d
platform/x86: thinkpad_acpi: Add ThinkPad PrivacyGuard

This feature is found optionally in T480s, T490, T490s.

The feature is called lcdshadow and visible via
/proc/acpi/ibm/lcdshadow.

The ACPI methods \_SB.PCI0.LPCB.EC.HKEY.{GSSS,SSSS,TSSS,CSSS} are
available in these machines. They get, set, toggle or change the state
apparently.

The patch was tested on a 5.0 series kernel on a T480s.

Signed-off-by: Alexander Schremmer <alex@alexanderweb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Documentation/admin-guide/laptops/thinkpad-acpi.rst
drivers/platform/x86/thinkpad_acpi.c