Merge branch '2022-03-09-events-subsystem' into next

To quote the author:
It is a common need in U-Boot to have one subsystem notify another
when something happens. An example is reading a partition table when a
new block device is set up.

It is also common to add weak functions and 'hook' functions to modify
how U-Boot works. See for example ft_board_setup() and the like.

U-Boot would benefit from a generic mechanism to handle these cases,
with the ability to hook into various 'events' in a
subsystem-independent and transparent way.

This series provides a way to create and dispatch events, with a way of
registering a 'spy' which watches for events of different types. This
allows 'hook' functions to be created in a generic way.

It also includes a script to list the hooks in an image, which is a bit
easier to debug than weak functions, as well as an 'event' command to
do the same from within U-Boot.

These 'static' events can be used to replace hooks like misc_init_f(),
for example. Also included is basic support for 'dynamic' events, where
a spy can be registered at runtime. The need for this is still being
figured out.

1 files changed, 10 insertions, 0 deletions

diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h
index 02002acb787..c420726287e 100644
--- a/include/dm/device-internal.h
+++ b/include/dm/device-internal.h
@@ -10,6 +10,7 @@
 #ifndef _DM_DEVICE_INTERNAL_H
 #define _DM_DEVICE_INTERNAL_H
 
+#include <event.h>
 #include <linker_lists.h>
 #include <dm/ofnode.h>
 
@@ -426,4 +427,13 @@ static inline void devres_release_all(struct udevice *dev)
 }
 
 #endif /* ! CONFIG_DEVRES */
+
+static inline int device_notify(const struct udevice *dev, enum event_t type)
+{
+#if CONFIG_IS_ENABLED(DM_EVENT)
+	return event_notify(type, &dev, sizeof(dev));
+#else
+	return 0;
+#endif
+}
 #endif