140 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * A general-purpose cyclic execution infrastructure, to allow "small"
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|  * (run-time wise) functions to be executed at a specified frequency.
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|  * Things like LED blinking or watchdog triggering are examples for such
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|  * tasks.
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|  *
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|  * Copyright (C) 2022 Stefan Roese <sr@denx.de>
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|  */
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| 
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| #include <cyclic.h>
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| #include <log.h>
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| #include <malloc.h>
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| #include <time.h>
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| #include <linux/errno.h>
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| #include <linux/list.h>
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| #include <asm/global_data.h>
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| 
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| DECLARE_GLOBAL_DATA_PTR;
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| 
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| void hw_watchdog_reset(void);
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| 
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| struct list_head *cyclic_get_list(void)
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| {
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| 	return &gd->cyclic->cyclic_list;
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| }
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| 
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| struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
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| 				    const char *name, void *ctx)
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| {
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| 	struct cyclic_info *cyclic;
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| 
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| 	if (!gd->cyclic->cyclic_ready) {
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| 		pr_debug("Cyclic IF not ready yet\n");
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| 		return NULL;
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| 	}
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| 
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| 	cyclic = calloc(1, sizeof(struct cyclic_info));
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| 	if (!cyclic) {
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| 		pr_debug("Memory allocation error\n");
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| 		return NULL;
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| 	}
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| 
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| 	/* Store values in struct */
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| 	cyclic->func = func;
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| 	cyclic->ctx = ctx;
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| 	cyclic->name = strdup(name);
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| 	cyclic->delay_us = delay_us;
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| 	cyclic->start_time_us = timer_get_us();
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| 	list_add_tail(&cyclic->list, &gd->cyclic->cyclic_list);
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| 
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| 	return cyclic;
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| }
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| 
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| int cyclic_unregister(struct cyclic_info *cyclic)
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| {
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| 	list_del(&cyclic->list);
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| 	free(cyclic);
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| 
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| 	return 0;
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| }
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| 
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| void cyclic_run(void)
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| {
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| 	struct cyclic_info *cyclic, *tmp;
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| 	uint64_t now, cpu_time;
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| 
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| 	/* Prevent recursion */
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| 	if (gd->cyclic->cyclic_running)
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| 		return;
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| 
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| 	gd->cyclic->cyclic_running = true;
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| 	list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list) {
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| 		/*
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| 		 * Check if this cyclic function needs to get called, e.g.
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| 		 * do not call the cyclic func too often
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| 		 */
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| 		now = timer_get_us();
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| 		if (time_after_eq64(now, cyclic->next_call)) {
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| 			/* Call cyclic function and account it's cpu-time */
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| 			cyclic->next_call = now + cyclic->delay_us;
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| 			cyclic->func(cyclic->ctx);
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| 			cyclic->run_cnt++;
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| 			cpu_time = timer_get_us() - now;
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| 			cyclic->cpu_time_us += cpu_time;
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| 
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| 			/* Check if cpu-time exceeds max allowed time */
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| 			if (cpu_time > CONFIG_CYCLIC_MAX_CPU_TIME_US) {
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| 				pr_err("cyclic function %s took too long: %lldus vs %dus max, disabling\n",
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| 				       cyclic->name, cpu_time,
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| 				       CONFIG_CYCLIC_MAX_CPU_TIME_US);
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| 
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| 				/* Unregister this cyclic function */
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| 				cyclic_unregister(cyclic);
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| 			}
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| 		}
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| 	}
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| 	gd->cyclic->cyclic_running = false;
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| }
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| 
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| void schedule(void)
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| {
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| 	/* The HW watchdog is not integrated into the cyclic IF (yet) */
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| 	if (IS_ENABLED(CONFIG_HW_WATCHDOG))
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| 		hw_watchdog_reset();
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| 
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| 	/*
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| 	 * schedule() might get called very early before the cyclic IF is
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| 	 * ready. Make sure to only call cyclic_run() when it's initalized.
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| 	 */
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| 	if (gd && gd->cyclic && gd->cyclic->cyclic_ready)
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| 		cyclic_run();
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| }
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| 
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| int cyclic_uninit(void)
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| {
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| 	struct cyclic_info *cyclic, *tmp;
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| 
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| 	list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list)
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| 		cyclic_unregister(cyclic);
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| 	gd->cyclic->cyclic_ready = false;
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| 
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| 	return 0;
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| }
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| 
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| int cyclic_init(void)
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| {
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| 	int size = sizeof(struct cyclic_drv);
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| 
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| 	gd->cyclic = (struct cyclic_drv *)malloc(size);
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| 	if (!gd->cyclic)
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| 		return -ENOMEM;
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| 
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| 	memset(gd->cyclic, '\0', size);
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| 	INIT_LIST_HEAD(&gd->cyclic->cyclic_list);
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| 	gd->cyclic->cyclic_ready = true;
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| 
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| 	return 0;
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| }
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