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-rw-r--r--src/soc/amd/common/acpi/alib.asl30
1 files changed, 30 insertions, 0 deletions
diff --git a/src/soc/amd/common/acpi/alib.asl b/src/soc/amd/common/acpi/alib.asl
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+++ b/src/soc/amd/common/acpi/alib.asl
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+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <amdblocks/alib.h>
+
+/* The ALIB method object is defined in an SSDT */
+External(\_SB.ALIB, MethodObj)
+
+/* Wrapper method that calls ALIB function 1 to report current AC/DC state. */
+Method (WAL1)
+{
+ /* Send ALIB Function 1 the AC/DC state */
+ Local0 = Buffer (0x03) {}
+ CreateWordField (Local0, 0, F1SZ)
+ CreateByteField (Local0, 2, F1DA)
+
+ /* First argument is size i.e. 3 bytes */
+ F1SZ = 3
+
+ /*
+ * Second argument is power state i.e. AC or DC.
+ * ALIB expects AC = 0, DC = 1.
+ * PWRS reports AC = 1, DC = 0.
+ *
+ * Hence, need to invert the state of PWRS.
+ */
+ F1DA = \PWRS ^ 1
+
+ Printf ("ALIB call: func 1 params %o", Local0)
+ \_SB.ALIB (ALIB_FUNCTION_REPORT_AC_DC_STATE, Local0)
+}