ACPI: Add _PLD support
Add a simple helper function to allow drivers to obtain the physical
device location data.
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index b002a47..adbbc1c 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -382,3 +382,33 @@
}
EXPORT_SYMBOL(acpi_evaluate_reference);
+
+acpi_status
+acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld *pld)
+{
+ acpi_status status;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *output;
+
+ status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
+
+ if (ACPI_FAILURE(status))
+ return status;
+
+ output = buffer.pointer;
+
+ if (!output || output->type != ACPI_TYPE_PACKAGE
+ || !output->package.count
+ || output->package.elements[0].type != ACPI_TYPE_BUFFER
+ || output->package.elements[0].buffer.length > sizeof(*pld)) {
+ status = AE_TYPE;
+ goto out;
+ }
+
+ memcpy(pld, output->package.elements[0].buffer.pointer,
+ output->package.elements[0].buffer.length);
+out:
+ kfree(buffer.pointer);
+ return status;
+}
+EXPORT_SYMBOL(acpi_get_physical_device_location);