1 files changed, 131 insertions, 0 deletions
diff --git a/src/soc/amd/common/acpi/upep.asl b/src/soc/amd/common/acpi/upep.asl
new file mode 100644
index 0000000000..3fcf2f7eb4
--- /dev/null
+++ b/src/soc/amd/common/acpi/upep.asl
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#define PEPD_DSM_UUID				"e3f32452-febc-43ce-9039-932122d37721"
+#define  PEPD_DSM_LPI_ENUM_FUNCTIONS		0
+#define   PEPD_DSM_LPI_ADDITIONAL_FUNCTIONS	1
+#define  PEPD_DSM_LPI_GET_DEVICE_CONSTRAINTS 	1
+
+#define PEPD_DSM_NOTIFICATIONS_UUID		"11e00d56-ce64-47ce-837b-1f898f9aa461"
+#define  PEPD_DSM_NOTIFICATION_ENUM_FUNCTIONS	0
+
+/*
+ * Power Engine Plug-in Device
+ *
+ * References:
+ *   * Intel Low Power S0 Idle
+ *   * AMD Modern Standby BIOS Implementation Guide - #56358
+ *   * Linux Kernel: drivers/acpi/x86/s2idle.c
+ *   * https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-firmware-notifications
+ */
+Scope (\_SB) {
+	Device (PEP) {
+		Name (_HID, "AMDI0005")
+		Name (_CID, EisaId ("PNP0D80"))
+		Name (_UID, One)
+
+		Method (_STA, 0, NotSerialized) {
+			Return (0x0F)
+		}
+
+		/*
+		 * Device constraints for low power states (may be used for debugging).
+		 * For now there is only one disabled dummy device, because Windows
+		 * expects at least one device and crashes without it with a bluescreen
+		 * (`INTERNAL_POWER_ERROR`). Returning an empty package does not work.
+		 */
+		Name (DEVL, Package() {
+			Package() {
+				0,		/* Disabled */
+				"\\DUMY",	/* \DUMY - not existent */
+				0,		/* Function States */
+				0		/* Minimum D-state */
+			}
+		})
+
+		/*
+		 * PEPD_DSM_UUID Helper method
+		 *
+		 * Arg0: Function Index
+		 */
+		Method (DSM0, 1, Serialized) {
+			Switch (ToInteger(Arg0)) {
+				/*
+				 * Return a bit field of the supported functions for
+				 * this UUID.
+				 */
+				Case (PEPD_DSM_LPI_ENUM_FUNCTIONS) {
+					Local0 = Buffer { 0x00 }
+					CreateByteField(Local0, 0x00, SUPP)
+
+					SUPP = PEPD_DSM_LPI_ADDITIONAL_FUNCTIONS
+					SUPP |= 1 << PEPD_DSM_LPI_GET_DEVICE_CONSTRAINTS
+
+					Return (Local0)
+				}
+				Case (PEPD_DSM_LPI_GET_DEVICE_CONSTRAINTS) {
+					Return (DEVL)
+				}
+				Default {
+					/* Unknown function */
+					Return (Buffer() { 0x00 })
+				}
+			}
+		}
+
+		/*
+		 * PEPD_DSM_NOTIFICATIONS_UUID Helper method
+		 *
+		 * Arg0: Function Index
+		 */
+		Method (DSM1, 1, Serialized) {
+			Switch (ToInteger(Arg0)) {
+				/*
+				 * Return a bit field of the supported functions for
+				 * this UUID.
+				 */
+				Case (PEPD_DSM_NOTIFICATION_ENUM_FUNCTIONS) {
+					/*
+					 * TODO(b/185586290): Add additional functions when
+					 * linux kernel driver is fixed.
+					 */
+					Return (Buffer() { 0x00 })
+				}
+				Default {
+					/* Unknown function */
+					Return (Buffer() { 0x00 })
+				}
+			}
+		}
+
+		/*
+		 * Device Specific Method
+		 *
+		 * Arg0: UUID
+		 * Arg1: Revision Id
+		 * Arg2: Function Index
+		 */
+		Method (_DSM, 4, Serialized)  {
+			Switch (ToBuffer(Arg0)) {
+				Case (ToUUID(PEPD_DSM_UUID)) {
+					/* Unsupported Revision */
+					If (ToInteger(Arg1) != 0) {
+						Return (Buffer() { 0x00 })
+					}
+
+					Return (DSM0(Arg2))
+				}
+				Case (ToUUID(PEPD_DSM_NOTIFICATIONS_UUID)) {
+					/* Unsupported Revision */
+					If (ToInteger(Arg1) != 0) {
+						Return (Buffer() { 0x00 })
+					}
+
+					Return (DSM1(Arg2))
+				}
+				Default {
+					Return (Buffer { 0x00 })
+				}
+			}
+		}
+	}
+}