ACPI: introduce module parameter acpi.aml_debug_output

Introduce module parameter acpi.aml_debug_output.

With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.

Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/debugfs.c b/drivers/acpi/debugfs.c
index abfcf9f..7de27d4 100644
--- a/drivers/acpi/debugfs.c
+++ b/drivers/acpi/debugfs.c
@@ -12,6 +12,14 @@
 #define _COMPONENT		ACPI_SYSTEM_COMPONENT
 ACPI_MODULE_NAME("debugfs");
 
+
+/* /sys/modules/acpi/parameters/aml_debug_output */
+
+module_param_named(aml_debug_output, acpi_gbl_enable_aml_debug_object,
+		   bool, 0644);
+MODULE_PARM_DESC(aml_debug_output,
+		 "To enable/disable the ACPI Debug Object output.");
+
 /* /sys/kernel/debug/acpi/custom_method */
 
 static ssize_t cm_write(struct file *file, const char __user * user_buf,