path: root/include/linux/of.h
diff options
authorAlan Tull <atull@opensource.altera.com>2016-11-01 14:14:22 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-10 17:03:35 +0100
commit39a842e22c1bf3ec3dce36e01fe8ba8ee66c80c8 (patch)
tree06def1c123cec59f796d6c1ff983ad768a67eafb /include/linux/of.h
parentc1eac0d034d36cfa0da3e35f2add6d6de1e696e5 (diff)
of/overlay: add of overlay notifications
This patch add of overlay notifications. When DT overlays are being added, some drivers/subsystems need to see device tree overlays before the changes go into the live tree. This is distinct from reconfig notifiers that are post-apply or post-remove and which issue very granular notifications without providing access to the context of a whole overlay. The following 4 notificatons are issued: OF_OVERLAY_PRE_APPLY OF_OVERLAY_POST_APPLY OF_OVERLAY_PRE_REMOVE OF_OVERLAY_POST_REMOVE In the case of pre-apply notification, if the notifier returns error, the overlay will be rejected. This patch exports two functions for registering/unregistering notifications: of_overlay_notifier_register(struct notifier_block *nb) of_overlay_notifier_unregister(struct notifier_block *nb) The of_mutex is held during these notifications. The notification data includes pointers to the overlay target and the overlay: struct of_overlay_notify_data { struct device_node *overlay; struct device_node *target; }; Signed-off-by: Alan Tull <atull@opensource.altera.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Moritz Fischer <moritz.fischer@ettus.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/of.h')
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/of.h b/include/linux/of.h
index 299aeb192727..d72f01009297 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1266,6 +1266,18 @@ static inline bool of_device_is_system_power_controller(const struct device_node
* Overlay support
+enum of_overlay_notify_action {
+struct of_overlay_notify_data {
+ struct device_node *overlay;
+ struct device_node *target;
/* ID based overlays; the API for external users */
@@ -1273,6 +1285,9 @@ int of_overlay_create(struct device_node *tree);
int of_overlay_destroy(int id);
int of_overlay_destroy_all(void);
+int of_overlay_notifier_register(struct notifier_block *nb);
+int of_overlay_notifier_unregister(struct notifier_block *nb);
static inline int of_overlay_create(struct device_node *tree)
@@ -1290,6 +1305,16 @@ static inline int of_overlay_destroy_all(void)
return -ENOTSUPP;
+static inline int of_overlay_notifier_register(struct notifier_block *nb)
+ return 0;
+static inline int of_overlay_notifier_unregister(struct notifier_block *nb)
+ return 0;
#endif /* _LINUX_OF_H */