mfd: Allow for bypass of cell resource conflict check

The upcoming VIA VX855 MFD driver needs to communicate resources
to subdevices where the resources may be claimed by ACPI.

Add a flag to mfd_cell to request that resources are not policed.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/mfd-core.c

@@ -65,9 +65,11 @@ static int mfd_add_device(struct device *parent, int id,
 			res[r].end   = cell->resources[r].end;
 		}
 
-		ret = acpi_check_resource_conflict(res);
-		if (ret)
-			goto fail_res;
+		if (!cell->ignore_resource_conflicts) {
+			ret = acpi_check_resource_conflict(res);
+			if (ret)
+				goto fail_res;
+		}
 	}
 
 	ret = platform_device_add_resources(pdev, res, cell->num_resources);

include/linux/mfd/core.h

@@ -44,6 +44,9 @@ struct mfd_cell {
 	 */
 	int			num_resources;
 	const struct resource	*resources;
+
+	/* don't check for resource conflicts */
+	bool			ignore_resource_conflicts;
 };
 
 extern int mfd_add_devices(struct device *parent, int id,