show_progress: add system wide progress stage notifier

Use case is e.g. board code that wants to register a client to light
status LEDs to indicate system state when no serial output is available.
This functionality doesn't increase code size due to linker GC when
CONFIG_PROGRESS_NOTIFIER is disabled.

There is a generic progress notifier provided that just logs the
status. This could be shared with the booted kernel via pstore or
the log as a whole written to a system setup USB drive.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20210503114901.13095-2-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 43 insertions, 0 deletions

diff --git a/include/progress.h b/include/progress.h
index 50b15fb12b..7230bd3a9b 100644
--- a/include/progress.h
+++ b/include/progress.h
@@ -3,6 +3,8 @@
 #define __PROGRSS_H
 
 #include <linux/types.h>
+#include <notifier.h>
+#include <errno.h>
 
 /* Initialize a progress bar. If max > 0 a one line progress
  * bar is printed where 'max' corresponds to 100%. If max == 0
@@ -15,4 +17,45 @@ void init_progression_bar(loff_t max);
  */
 void show_progress(loff_t now);
 
+extern struct notifier_head progress_notifier;
+
+enum progress_stage {
+	PROGRESS_UNSPECIFIED = 0,
+	PROGRESS_UPDATING,
+	PROGRESS_UPDATE_SUCCESS,
+	PROGRESS_UPDATE_FAIL,
+};
+
+/*
+ * Notifier list for code which wants to be called at progress
+ * This could use by board code to e.g. flash a LED during updates
+ */
+extern struct notifier_head progress_notifier_list;
+
+/* generic client that just logs the state */
+extern struct notifier_block progress_log_client;
+
+static inline int progress_register_client(struct notifier_block *nb)
+{
+	if (!IS_ENABLED(CONFIG_PROGRESS_NOTIFIER))
+		return -ENOSYS;
+	return notifier_chain_register(&progress_notifier_list, nb);
+}
+
+static inline int progress_unregister_client(struct notifier_block *nb)
+{
+	if (!IS_ENABLED(CONFIG_PROGRESS_NOTIFIER))
+		return -ENOSYS;
+	return notifier_chain_unregister(&progress_notifier_list, nb);
+}
+
+static inline int progress_notifier_call_chain(enum progress_stage stage, const char *prefix)
+{
+	if (!IS_ENABLED(CONFIG_PROGRESS_NOTIFIER))
+		return -ENOSYS;
+
+	/* clients should not modify the prefix */
+	return notifier_call_chain(&progress_notifier_list, stage, (char *)(prefix ?: ""));
+}
+
 #endif /*  __PROGRSS_H */