acpi: add aml_call0() helper

it will help to call a method with 0 arguments

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 74316d1..b4fff5f 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -540,6 +540,14 @@
 }
 
 /* helper to call method with 1 argument */
+Aml *aml_call0(const char *method)
+{
+    Aml *var = aml_alloc();
+    build_append_namestring(var->buf, "%s", method);
+    return var;
+}
+
+/* helper to call method with 1 argument */
 Aml *aml_call1(const char *method, Aml *arg1)
 {
     Aml *var = aml_alloc();
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 40a95d8..81326bd 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -236,6 +236,7 @@
 Aml *aml_decrement(Aml *arg);
 Aml *aml_index(Aml *arg1, Aml *idx);
 Aml *aml_notify(Aml *arg1, Aml *arg2);
+Aml *aml_call0(const char *method);
 Aml *aml_call1(const char *method, Aml *arg1);
 Aml *aml_call2(const char *method, Aml *arg1, Aml *arg2);
 Aml *aml_call3(const char *method, Aml *arg1, Aml *arg2, Aml *arg3);