platform/x86: Add custom surface3 platform device for controlling LID

The LID state provided by ACPI on the Surface 3 is not accurate.
The ACPI node doesn't get notified on LID open, which means the
LID input switch stays close most of the time.

Fortunatelly, there is a WMI method which directly queries the
GPIO underneath the LID state, so it's far more reliable than ACPI.
To get the notifications that the LID was opened/closed, we can
rely on the ACPI notification of the touchscreen: the DSDT shows
that the touchscreen will get notified on close/open as it also
controls its _STA method.

Note that we need to set the tag "power-switch" to the LID
input node through a udev rule for logind to accept it:

SUBSYSTEM=="input", KERNEL=="event*", KERNELS=="surface3-wmi", \
	TAG+="power-switch"

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 4639d97..0414d76d 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -363,6 +363,18 @@ config IDEAPAD_LAPTOP
 	  This is a driver for Lenovo IdeaPad netbooks contains drivers for
 	  rfkill switch, hotkey, fan control and backlight control.
 
+config SURFACE3_WMI
+	tristate "Surface 3 WMI Driver"
+	depends on ACPI_WMI
+	depends on DMI
+	depends on INPUT
+	depends on SPI
+	---help---
+	  Say Y here if you have a Surface 3.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called surface3-wmi.
+
 config THINKPAD_ACPI
 	tristate "ThinkPad ACPI Laptop Extras"
 	depends on ACPI