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.

3 files changed, 12 insertions, 4 deletions

diff --git a/board/google/chromebook_coral/coral.c b/board/google/chromebook_coral/coral.c
index 182cf7517a9..9e23f5cd31e 100644
--- a/board/google/chromebook_coral/coral.c
+++ b/board/google/chromebook_coral/coral.c
@@ -10,6 +10,7 @@
 #include <command.h>
 #include <cros_ec.h>
 #include <dm.h>
+#include <event.h>
 #include <init.h>
 #include <log.h>
 #include <sysinfo.h>
@@ -32,11 +33,12 @@ struct cros_gpio_info {
 	int flags;
 };
 
-int misc_init_f(void)
+static int coral_check_ll_boot(void *ctx, struct event *event)
 {
 	if (!ll_boot_init()) {
 		printf("Running as secondary loader");
-		if (gd->arch.coreboot_table) {
+		if (CONFIG_IS_ENABLED(COREBOOT_SYSINFO) &&
+		    gd->arch.coreboot_table) {
 			int ret;
 
 			printf(" (found coreboot table at %lx)",
@@ -55,6 +57,7 @@ int misc_init_f(void)
 
 	return 0;
 }
+EVENT_SPY(EVT_MISC_INIT_F, coral_check_ll_boot);
 
 int arch_misc_init(void)
 {
diff --git a/board/keymile/kmcent2/kmcent2.c b/board/keymile/kmcent2/kmcent2.c
index ca24b960c76..44865384f65 100644
--- a/board/keymile/kmcent2/kmcent2.c
+++ b/board/keymile/kmcent2/kmcent2.c
@@ -6,6 +6,7 @@
  * Copyright 2013 Freescale Semiconductor, Inc.
  */
 
+#include <event.h>
 #include <asm/cache.h>
 #include <asm/fsl_fdt.h>
 #include <asm/fsl_law.h>
@@ -181,7 +182,7 @@ unsigned long get_serial_clock(unsigned long dummy)
 	return (gd->bus_clk / 2);
 }
 
-int misc_init_f(void)
+static int kmcent2_misc_init_f(void *ctx, struct event *event)
 {
 	/* configure QRIO pis for i2c deblocking */
 	i2c_deblock_gpio_cfg();
@@ -209,6 +210,7 @@ int misc_init_f(void)
 
 	return 0;
 }
+EVENT_SPY(EVT_MISC_INIT_F, kmcent2_misc_init_f);
 
 #define USED_SRDS_BANK 0
 #define EXPECTED_SRDS_RFCK SRDS_PLLCR0_RFCK_SEL_100
diff --git a/board/keymile/pg-wcom-ls102xa/pg-wcom-ls102xa.c b/board/keymile/pg-wcom-ls102xa/pg-wcom-ls102xa.c
index 467f1109517..ed8142d868f 100644
--- a/board/keymile/pg-wcom-ls102xa/pg-wcom-ls102xa.c
+++ b/board/keymile/pg-wcom-ls102xa/pg-wcom-ls102xa.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <event.h>
 #include <i2c.h>
 #include <asm/io.h>
 #include <asm/arch/immap_ls102xa.h>
@@ -109,12 +110,14 @@ int board_early_init_f(void)
 	return 0;
 }
 
-int misc_init_f(void)
+static int pg_wcom_misc_init_f(void *ctx, struct event *event)
 {
 	if (IS_ENABLED(CONFIG_PG_WCOM_UBOOT_UPDATE_SUPPORTED))
 		check_for_uboot_update();
+
 	return 0;
 }
+EVENT_SPY(EVT_MISC_INIT_F, pg_wcom_misc_init_f);
 
 int board_init(void)
 {