platform/surface: aggregator: Make client device removal more generic

Currently, there are similar functions defined in the Aggregator
Registry and the controller core.

Make client device removal more generic and export it. We can then use
this function later on to remove client devices from device hubs as well
as the controller and avoid re-defining similar things.

Signed-off-by: Maximilian Luz <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/surface/aggregator/bus.c

···
 }
 
 /**
- * ssam_controller_remove_clients() - Remove SSAM client devices registered as
- * direct children under the given controller.
- * @ctrl: The controller to remove all direct clients for.
+ * ssam_remove_clients() - Remove SSAM client devices registered as direct
+ * children under the given parent device.
+ * @dev: The (parent) device to remove all direct clients for.
  *
- * Remove all SSAM client devices registered as direct children under the
- * given controller. Note that this only accounts for direct children of the
- * controller device. This does not take care of any client devices where the
- * parent device has been manually set before calling ssam_device_add. Refer
- * to ssam_device_add()/ssam_device_remove() for more details on those cases.
- *
- * To avoid new devices being added in parallel to this call, the main
- * controller lock (not statelock) must be held during this (and if
- * necessary, any subsequent deinitialization) call.
+ * Remove all SSAM client devices registered as direct children under the given
+ * device. Note that this only accounts for direct children of the device.
+ * Refer to ssam_device_add()/ssam_device_remove() for more details.
  */
-void ssam_controller_remove_clients(struct ssam_controller *ctrl)
+void ssam_remove_clients(struct device *dev)
 {
-	struct device *dev;
-
-	dev = ssam_controller_device(ctrl);
 	device_for_each_child_reverse(dev, NULL, ssam_remove_device);
 }
+EXPORT_SYMBOL_GPL(ssam_remove_clients);
 
 /**
  * ssam_bus_register() - Register and set-up the SSAM client device bus.

drivers/platform/surface/aggregator/bus.h

···
 
 #ifdef CONFIG_SURFACE_AGGREGATOR_BUS
 
-void ssam_controller_remove_clients(struct ssam_controller *ctrl);
-
 int ssam_bus_register(void);
 void ssam_bus_unregister(void);
 
 #else /* CONFIG_SURFACE_AGGREGATOR_BUS */
 
-static inline void ssam_controller_remove_clients(struct ssam_controller *ctrl) {}
 static inline int ssam_bus_register(void) { return 0; }
 static inline void ssam_bus_unregister(void) {}
 

drivers/platform/surface/aggregator/core.c

···
 #include <linux/sysfs.h>
 
 #include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/device.h>
 
 #include "bus.h"
 #include "controller.h"
···
 	ssam_controller_lock(ctrl);
 
 	/* Remove all client devices. */
-	ssam_controller_remove_clients(ctrl);
+	ssam_remove_clients(&serdev->dev);
 
 	/* Act as if suspending to silence events. */
 	status = ssam_ctrl_notif_display_off(ctrl);

include/linux/surface_aggregator/device.h

···
 		      ssam_device_driver_unregister)
 
 
+/* -- Helpers for controller and hub devices. ------------------------------- */
+
+#ifdef CONFIG_SURFACE_AGGREGATOR_BUS
+void ssam_remove_clients(struct device *dev);
+#else /* CONFIG_SURFACE_AGGREGATOR_BUS */
+static inline void ssam_remove_clients(struct device *dev) {}
+#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */
+
+
 /* -- Helpers for client-device requests. ----------------------------------- */
 
 /**