Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Name(_GPE, 0)
// Define that the EC SCI is bit 0 of the GP_STS register
// Not required for HW-Reduced ACPI platforms
OperationRegion(ECOR, EmbeddedControl, 0, 0xFF)
Field(ECOR, ByteAcc, Lock, Preserve) {
// Field definitions go here
}
}
12.12 Defining an EC SMBus Host Controller in ACPI
Namespace
An EC-SMB-HC device is defined using the named device object. The EC-SMB- HC’s device
object requires the following elements:
Table 12-301 EC SMBus HC Device Objects
Object
_HID
_EC
Description
Named object that provides the EC-SMB- HC’s Plug and Play identifier. This value is be set to
ACPI0001. _HID is a standard device configuration control method defined in Section 6.1.5,
“_HID (Hardware ID).”
Named object that evaluates to a WORD that defines the SMBus attributes needed by the
SMBus driver. _EC is the Embedded Controller Offset Query Control Method. The most
significant byte is the address offset in embedded controller space of the SMBus controller; the
least significant byte is the query value for all SMBus events.
12.12.1 Example: EC SMBus Host Controller ASL-Code
Example ASL code that defines an SMB-HC from within an embedded controller device is shown
below:
Device(EC0)
{
Name(_HID, EISAID("PNP0C09"))
Name(_CRS, ResourceTemplate()
{
IO(Decode16, 0x62, 0x62, 0, 1), // Status port
IO(Decode16, 0x66, 0x66, 0, 1) // command port
})
Name(_GPE, 0)
Device (SMB0)
{
Name(_HID, "ACPI0001")
Name(_UID, 0)
Name(_EC, 0x2030)
:
}
// EC-SMB-HC
// Unique device identifier
// EC offset 0x20, query bit 0x30
658 April, 2015 Version 6.0