Add support for packages as the first element of _PRW. This may allow

some machines to enable wake events for more devices although I haven't
seen a system yet that uses this form.  Also, introduce acpi_GetReference()
which retrieves an object reference from various types.

2 files changed, 64 insertions, 26 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index 4b3a45e..83b76a9 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -1983,9 +1983,11 @@ void
 acpi_device_enable_wake_event(ACPI_HANDLE h)
 {
     struct acpi_softc		*sc;
+    uint32_t			gpe_bit, lowest_wake;
+    ACPI_HANDLE			handle;
     ACPI_STATUS			status;
     ACPI_BUFFER			prw_buffer;
-    ACPI_OBJECT			*res;
+    ACPI_OBJECT			*res, *res2;
 
     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
 
@@ -1994,67 +1996,72 @@ acpi_device_enable_wake_event(ACPI_HANDLE h)
 	return;
 
     /*
-     * _PRW object is only required for devices that have the ability
-     * to wake the system from a system sleeping state.
+     * The _PRW object (7.2.9) is only required for devices that have the
+     * ability to wake the system from a sleeping state.
      */
+    prw_buffer.Pointer = NULL;
     prw_buffer.Length = ACPI_ALLOCATE_BUFFER;
     status = AcpiEvaluateObject(h, "_PRW", NULL, &prw_buffer);
     if (ACPI_FAILURE(status))
 	return;
-
     res = (ACPI_OBJECT *)prw_buffer.Pointer;
     if (res == NULL)
 	return;
-
-    if ((res->Type != ACPI_TYPE_PACKAGE) || (res->Package.Count < 2)) {
+    if (!ACPI_PKG_VALID(res, 2))
 	goto out;
-    }
 
     /*
-     * The element 1 of the _PRW object:
-     * The lowest power system sleeping state that can be entered
-     * while still providing wake functionality.
-     * The sleeping state being entered must be greater or equal to
-     * the power state declared in element 1 of the _PRW object.
+     * Element 1 of the _PRW object:
+     * The lowest power system sleeping state that can be entered while still
+     * providing wake functionality.  The sleeping state being entered must
+     * be less than (i.e., higher power) or equal to this value.
      */
-    if (res->Package.Elements[1].Type != ACPI_TYPE_INTEGER)
+    if (acpi_PkgInt32(res, 1, &lowest_wake) != 0)
 	goto out;
-
-    if (sc->acpi_sstate > res->Package.Elements[1].Integer.Value)
+    if (sc->acpi_sstate > lowest_wake)
 	goto out;
 
     /*
-     * The element 0 of the _PRW object:
+     * Element 0 of the _PRW object:
      */
-    switch(res->Package.Elements[0].Type) {
+    switch (res->Package.Elements[0].Type) {
     case ACPI_TYPE_INTEGER:
-	/* 
+	/*
 	 * If the data type of this package element is numeric, then this
 	 * _PRW package element is the bit index in the GPEx_EN, in the
 	 * GPE blocks described in the FADT, of the enable bit that is
 	 * enabled for the wake event.
 	 */
-
-	status = AcpiEnableGpe(NULL, res->Package.Elements[0].Integer.Value,
-			       ACPI_EVENT_WAKE_ENABLE);
+	gpe_bit = res->Package.Elements[0].Integer.Value;
+	status = AcpiEnableGpe(NULL, gpe_bit, ACPI_EVENT_WAKE_ENABLE);
 	if (ACPI_FAILURE(status))
-	    printf("%s: EnableEvent Failed\n", __func__);
+	    printf("wake enable: AcpiEnableGpe failed for %u\n",
+		   gpe_bit);
 	break;
     case ACPI_TYPE_PACKAGE:
 	/*
-	 * XXX TBD
-	 *
 	 * If the data type of this package element is a package, then this
 	 * _PRW package element is itself a package containing two
-	 * elements. The first is an object reference to the GPE Block
+	 * elements.  The first is an object reference to the GPE Block
 	 * device that contains the GPE that will be triggered by the wake
-	 * event. The second element is numeric and it contains the bit
+	 * event.  The second element is numeric and it contains the bit
 	 * index in the GPEx_EN, in the GPE Block referenced by the
 	 * first element in the package, of the enable bit that is enabled for
 	 * the wake event.
+	 *
 	 * For example, if this field is a package then it is of the form:
 	 * Package() {\_SB.PCI0.ISA.GPE, 2}
 	 */
+	res2 = &res->Package.Elements[0];
+	if (!ACPI_PKG_VALID(res2, 2))
+	    goto out;
+	handle = acpi_GetReference(NULL, &res2->Package.Elements[0]);
+	if (handle == NULL || acpi_PkgInt32(res2, 1, &gpe_bit) != 0)
+	    goto out;
+	status = AcpiEnableGpe(handle, gpe_bit, ACPI_EVENT_WAKE_ENABLE);
+	if (ACPI_FAILURE(status))
+	    printf("wake enable: AcpiEnableGpe (package) failed for %u\n",
+		   gpe_bit);
 	break;
     default:
 	break;
diff --git a/sys/dev/acpica/acpi_package.c b/sys/dev/acpica/acpi_package.c
index 0011308..41f7581 100644
--- a/sys/dev/acpica/acpi_package.c
+++ b/sys/dev/acpica/acpi_package.c
@@ -123,3 +123,34 @@ acpi_PkgGas(device_t dev, ACPI_OBJECT *res, int idx, int *rid,
 
     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);
+}