1 files changed, 134 insertions, 0 deletions
diff --git a/common/cyclic.c b/common/cyclic.c
new file mode 100644
index 00000000000..ec952a01ee1
--- /dev/null
+++ b/common/cyclic.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * A general-purpose cyclic execution infrastructure, to allow "small"
+ * (run-time wise) functions to be executed at a specified frequency.
+ * Things like LED blinking or watchdog triggering are examples for such
+ * tasks.
+ *
+ * Copyright (C) 2022 Stefan Roese <sr@denx.de>
+ */
+
+#include <cyclic.h>
+#include <log.h>
+#include <malloc.h>
+#include <time.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <asm/global_data.h>
+#include <u-boot/schedule.h>
+#include <uthread.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+void hw_watchdog_reset(void);
+
+struct hlist_head *cyclic_get_list(void)
+{
+	/* Silence "discards 'volatile' qualifier" warning. */
+	return (struct hlist_head *)&gd->cyclic_list;
+}
+
+static bool cyclic_is_registered(const struct cyclic_info *cyclic)
+{
+	const struct cyclic_info *c;
+
+	hlist_for_each_entry(c, cyclic_get_list(), list) {
+		if (c == cyclic)
+			return true;
+	}
+
+	return false;
+}
+
+void cyclic_register(struct cyclic_info *cyclic, cyclic_func_t func,
+		     uint64_t delay_us, const char *name)
+{
+	cyclic_unregister(cyclic);
+
+	memset(cyclic, 0, sizeof(*cyclic));
+
+	/* Store values in struct */
+	cyclic->func = func;
+	cyclic->name = name;
+	cyclic->delay_us = delay_us;
+	cyclic->start_time_us = get_timer_us(0);
+	hlist_add_head(&cyclic->list, cyclic_get_list());
+}
+
+void cyclic_unregister(struct cyclic_info *cyclic)
+{
+	if (!cyclic_is_registered(cyclic))
+		return;
+
+	hlist_del(&cyclic->list);
+}
+
+static void cyclic_run(void)
+{
+	struct cyclic_info *cyclic;
+	struct hlist_node *tmp;
+	uint64_t now, cpu_time;
+
+	/* Prevent recursion */
+	if (gd->flags & GD_FLG_CYCLIC_RUNNING)
+		return;
+
+	gd->flags |= GD_FLG_CYCLIC_RUNNING;
+	hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list) {
+		/*
+		 * Check if this cyclic function needs to get called, e.g.
+		 * do not call the cyclic func too often
+		 */
+		now = get_timer_us(0);
+		if (time_after_eq64(now, cyclic->next_call)) {
+			/* Call cyclic function and account it's cpu-time */
+			cyclic->next_call = now + cyclic->delay_us;
+			cyclic->func(cyclic);
+			cyclic->run_cnt++;
+			cpu_time = get_timer_us(0) - now;
+			cyclic->cpu_time_us += cpu_time;
+
+			/* Check if cpu-time exceeds max allowed time */
+			if ((cpu_time > CONFIG_CYCLIC_MAX_CPU_TIME_US) &&
+			    (!cyclic->already_warned)) {
+				pr_err("cyclic function %s took too long: %lldus vs %dus max\n",
+				       cyclic->name, cpu_time,
+				       CONFIG_CYCLIC_MAX_CPU_TIME_US);
+
+				/*
+				 * Don't disable this function, just warn once
+				 * about this exceeding CPU time usage
+				 */
+				cyclic->already_warned = true;
+			}
+		}
+	}
+	gd->flags &= ~GD_FLG_CYCLIC_RUNNING;
+}
+
+void schedule(void)
+{
+	/* The HW watchdog is not integrated into the cyclic IF (yet) */
+	if (IS_ENABLED(CONFIG_HW_WATCHDOG))
+		hw_watchdog_reset();
+
+	/*
+	 * schedule() might get called very early before the cyclic IF is
+	 * ready. Make sure to only call cyclic_run() when it's initalized.
+	 */
+	if (gd)
+		cyclic_run();
+
+	uthread_schedule();
+}
+
+int cyclic_unregister_all(void)
+{
+	struct cyclic_info *cyclic;
+	struct hlist_node *tmp;
+
+	hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list)
+		cyclic_unregister(cyclic);
+
+	return 0;
+}