Reference object type?

[Nate Lawson <nate-Y6VGUYTwhu0@public.gmane.org>]

Bob and others,

I can't seem to figure out the canonical ways to retrieve a Reference
type.  The ACPI-CA code seems to indicate:
    Type == ACPI_TYPE_LOCAL_REFERENCE and use obj->Reference.Handle

I also support ACPI_TYPE_ANY since that seems to be the previous type.
Strings seem to be another way.  This is needed for objects like this:
    Package() {\_SB.PCI0.ISA.GPE, 2}

Anyway, comments on my code below are welcome.  It retrieves a handle from
various forms of a reference and seems to have worked for a few years, at
least for thermal zones.

Thanks,
-Nate

----
 njl         2004/04/08 23:55:50 PDT

  FreeBSD src repository

  Modified files:
    sys/dev/acpica       acpi_powerres.c acpi_thermal.c
  Log:
  Replace more ad-hoc versions of acpi_GetReference().  Since the type of
  Reference objects changed from ACPI_TYPE_ANY to ACPI_TYPE_LOCAL_REFERENCE
  in Oct. 2002, this may help systems where switching the cooler on failed.
  We support both types for now until this sorts out.

  Revision  Changes    Path
  1.136     +33 -26    src/sys/dev/acpica/acpi.c
  1.3       +31 -0     src/sys/dev/acpica/acpi_package.c
  1.20      +3 -23     src/sys/dev/acpica/acpi_powerres.c
  1.41      +30 -69    src/sys/dev/acpica/acpi_thermal.c

--- src/sys/dev/acpica/acpi_package.c:1.2	Tue Dec 23 10:26:53 2003
+++ src/sys/dev/acpica/acpi_package.c	Thu Apr  8 23:40:03 2004
@@ -122,4 +122,35 @@
 	return (ENXIO);

     return (0);
+}
+
+ACPI_HANDLE
+acpi_GetReference(ACPI_HANDLE scope, ACPI_OBJECT *obj)
+{
+    ACPI_HANDLE h;
+
+    if (obj == NULL)
+	return (NULL);
+
+    switch (obj->Type) {
+    case ACPI_TYPE_LOCAL_REFERENCE:
+    case ACPI_TYPE_ANY:
+	h = obj->Reference.Handle;
+	break;
+    case ACPI_TYPE_STRING:
+	/*
+	 * The String object usually contains a fully-qualified path, so
+	 * scope can be NULL.
+	 *
+	 * XXX This may not always be the case.
+	 */
+	if (ACPI_FAILURE(AcpiGetHandle(scope, obj->String.Pointer, &h)))
+	    h = NULL;
+	break;
+    default:
+	h = NULL;
+	break;
+    }
+
+    return (h);
 }


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