Windows button array Device-Specific Method (_DSM)
To support evolution of the Windows Button user interface (UI), Windows defines a Device-Specific Method (_DSM) for the Windows button array device with the function that is described in this article.
Function 1: Power Button Properties
The _DSM control method parameters for the power button properties function are as follows:
Arguments
Arg0: UUID = dfbcf3c5-e7a5-44e6-9c1f-29c76f6e059c
Arg1: Revision ID = 0
Arg2: Function index = 1
Arg3: Empty package (not used)
Return
An integer (DWORD) that has the following bit-field definitions:
Bits 31 to 33: Reserved (must be 0).
Bit 2: This bit should be set to 1 if the power button is configured to detect both press and release events, and to report these events to the operating system. Otherwise, this bit should be 0.
Bit 1: This bit should be set to 1 if power button is wired to an interrupt controller (GPIO or otherwise) that supports level-detection. Otherwise, this bit should be 0.
Bit 0: This bit should be set to 1 if the platform supports ACPI Power Button Override time of 10 seconds or greater. Otherwise, this bit should be 0.
Function index 0 of every _DSM is a query function that returns the set of supported function indexes, and is always required. For more information, see section 9.14.1, "_DSM (Device Specific Method)", in the ACPI 5.0 specification.