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

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, 4 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/hwinit-common.c b/arch/arm/mach-omap2/hwinit-common.c
index 3da50f9..c4a8eab 100644
--- a/arch/arm/mach-omap2/hwinit-common.c
+++ b/arch/arm/mach-omap2/hwinit-common.c
@@ -12,6 +12,7 @@
  */
 #include <common.h>
 #include <debug_uart.h>
+#include <event.h>
 #include <fdtdec.h>
 #include <init.h>
 #include <spl.h>
@@ -239,11 +240,13 @@ void board_init_f(ulong dummy)
 }
 #endif
 
-int arch_cpu_init_dm(void)
+static int omap2_system_init(void *ctx, struct event *event)
 {
 	early_system_init();
+
 	return 0;
 }
+EVENT_SPY(EVT_DM_POST_INIT, omap2_system_init);
 
 /*
  * Routine: wait_for_command_complete