1 files changed, 139 insertions, 0 deletions
diff --git a/common/cyclic.c b/common/cyclic.c
new file mode 100644
index 0000000..b3c180b
--- /dev/null
+++ b/common/cyclic.c
@@ -0,0 +1,139 @@
+// 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>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+void hw_watchdog_reset(void);
+
+struct list_head *cyclic_get_list(void)
+{
+	return &gd->cyclic->cyclic_list;
+}
+
+struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
+				    const char *name, void *ctx)
+{
+	struct cyclic_info *cyclic;
+
+	if (!gd->cyclic->cyclic_ready) {
+		pr_debug("Cyclic IF not ready yet\n");
+		return NULL;
+	}
+
+	cyclic = calloc(1, sizeof(struct cyclic_info));
+	if (!cyclic) {
+		pr_debug("Memory allocation error\n");
+		return NULL;
+	}
+
+	/* Store values in struct */
+	cyclic->func = func;
+	cyclic->ctx = ctx;
+	cyclic->name = strdup(name);
+	cyclic->delay_us = delay_us;
+	cyclic->start_time_us = timer_get_us();
+	list_add_tail(&cyclic->list, &gd->cyclic->cyclic_list);
+
+	return cyclic;
+}
+
+int cyclic_unregister(struct cyclic_info *cyclic)
+{
+	list_del(&cyclic->list);
+	free(cyclic);
+
+	return 0;
+}
+
+void cyclic_run(void)
+{
+	struct cyclic_info *cyclic, *tmp;
+	uint64_t now, cpu_time;
+
+	/* Prevent recursion */
+	if (gd->cyclic->cyclic_running)
+		return;
+
+	gd->cyclic->cyclic_running = true;
+	list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list) {
+		/*
+		 * Check if this cyclic function needs to get called, e.g.
+		 * do not call the cyclic func too often
+		 */
+		now = timer_get_us();
+		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->ctx);
+			cyclic->run_cnt++;
+			cpu_time = timer_get_us() - now;
+			cyclic->cpu_time_us += cpu_time;
+
+			/* Check if cpu-time exceeds max allowed time */
+			if (cpu_time > CONFIG_CYCLIC_MAX_CPU_TIME_US) {
+				pr_err("cyclic function %s took too long: %lldus vs %dus max, disabling\n",
+				       cyclic->name, cpu_time,
+				       CONFIG_CYCLIC_MAX_CPU_TIME_US);
+
+				/* Unregister this cyclic function */
+				cyclic_unregister(cyclic);
+			}
+		}
+	}
+	gd->cyclic->cyclic_running = false;
+}
+
+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 && gd->cyclic && gd->cyclic->cyclic_ready)
+		cyclic_run();
+}
+
+int cyclic_uninit(void)
+{
+	struct cyclic_info *cyclic, *tmp;
+
+	list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list)
+		cyclic_unregister(cyclic);
+	gd->cyclic->cyclic_ready = false;
+
+	return 0;
+}
+
+int cyclic_init(void)
+{
+	int size = sizeof(struct cyclic_drv);
+
+	gd->cyclic = (struct cyclic_drv *)malloc(size);
+	if (!gd->cyclic)
+		return -ENOMEM;
+
+	memset(gd->cyclic, '\0', size);
+	INIT_LIST_HEAD(&gd->cyclic->cyclic_list);
+	gd->cyclic->cyclic_ready = true;
+
+	return 0;
+}