linux/Documentation/admin-guide/laptops
Vishnu Sankar 5223acf679
platform/x86: thinkpad_acpi: Add USB-C Security (USCS) support
Newer ThinkPad systems expose a USB-C Security (Restricted Mode) feature.
When active, USB-C data connections are disabled while power delivery is
preserved. This is useful for kiosk and physically-secured deployments.

Hardware interface:

The HKEY device exposes a read-only ACPI method USCS():

  Return value bit layout:
    Bit 16 : Capability flag (1 = feature present on this SKU)
    Bit  0 : Current state  (0 = security OFF, 1 = security ON)

The sysfs attribute is read-only.

The Fn+U followed by Fn+S hotkey chord is the only way to toggle the
hardware state.

Hotkey:

Fn+U followed by Fn+S generates HKEY event 0x131e.

sysfs interface:

  /sys/devices/platform/thinkpad_acpi/usb_c_security  (read-only)
  "enabled\n"  -- data connections are currently blocked
  "disabled\n" -- data connections are currently allowed

  The attribute is hidden on SKUs where the USCS capability bit (bit 16)
  is not set, so there is no ABI impact on unsupported hardware.

Suggested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
Link: https://patch.msgid.link/20260709021504.465792-1-vishnuocv@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2026-07-09 16:43:47 +03:00
..
alienware-wmi.rst docs: alienware-wmi: fix typo 2026-01-05 16:29:00 +02:00
asus-laptop.rst
disk-shock-protection.rst Replace HTTP links with HTTPS ones: Documentation/admin-guide 2020-07-05 14:13:00 -06:00
index.rst mm/block/fs: remove laptop_mode 2026-01-20 19:24:47 -08:00
lg-laptop.rst platform/x86: lg-laptop: Fix WMAB call in fan_mode_store() 2025-09-25 12:21:43 +03:00
samsung-galaxybook.rst platform/x86: samsung-galaxybook: Add samsung-galaxybook driver 2025-02-07 13:57:03 +02:00
sony-laptop.rst
sonypi.rst docs: sonypi: Fix stale header file path 2026-06-01 13:02:20 -06:00
thinkpad-acpi.rst platform/x86: thinkpad_acpi: Add USB-C Security (USCS) support 2026-07-09 16:43:47 +03:00
toshiba_haps.rst docs: toshiba_haps: fix grammar error in SSD warning 2026-02-14 10:17:20 -07:00
uniwill-laptop.rst platform/x86: uniwill-laptop: Add support for USB powershare 2026-07-06 11:27:06 +03:00