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| author | Alexander Schremmer <alex@alexanderweb.de> | 2019-08-22 14:48:33 +0300 |
|---|---|---|
| committer | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-09-07 21:16:09 +0300 |
| commit | 110ea1d833ad291272d52e0a40a06157a3d9ba17 (patch) | |
| tree | 3acdf105f4d3b4d0b076092f3028f130d8cd3042 /Documentation/admin-guide/laptops | |
| parent | ad0d315b4d4e7138f43acf03308192ec00e9614d (diff) | |
| download | linux-110ea1d833ad291272d52e0a40a06157a3d9ba17.tar.xz | |
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>
Diffstat (limited to 'Documentation/admin-guide/laptops')
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index adea0bf2acc5..822907dcc845 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -49,6 +49,7 @@ detailed description): - Fan control and monitoring: fan speed, fan enable/disable - WAN enable and disable - UWB enable and disable + - LCD Shadow (PrivacyGuard) enable and disable A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1409,6 +1410,28 @@ Sysfs notes Documentation/driver-api/rfkill.rst for details. +LCD Shadow control +------------------ + +procfs: /proc/acpi/ibm/lcdshadow + +Some newer T480s and T490s ThinkPads provide a feature called +PrivacyGuard. By turning this feature on, the usable vertical and +horizontal viewing angles of the LCD can be limited (as if some privacy +screen was applied manually in front of the display). + +procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo '0' >/proc/acpi/ibm/lcdshadow + echo '1' >/proc/acpi/ibm/lcdshadow + +The first command ensures the best viewing angle and the latter one turns +on the feature, restricting the viewing angles. + + EXPERIMENTAL: UWB ----------------- |