mfd: core: Add helper function to register hotplug devices

Hot-pluggable multi-function devices should always be registered with
PLATFORM_DEVID_AUTO to avoid name collisions on the platform bus. This
helper also hides the memory map and irq parameters, which aren't used
by hot-pluggable (e.g. USB-based) devices.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index 73e1709..a76bc10 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -111,6 +111,13 @@
 			   struct resource *mem_base,
 			   int irq_base, struct irq_domain *irq_domain);
 
+static inline int mfd_add_hotplug_devices(struct device *parent,
+		const struct mfd_cell *cells, int n_devs)
+{
+	return mfd_add_devices(parent, PLATFORM_DEVID_AUTO, cells, n_devs,
+			NULL, 0, NULL);
+}
+
 extern void mfd_remove_devices(struct device *parent);
 
 #endif