1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * A general-purpose cyclic execution infrastructure, to allow "small"
4  * (run-time wise) functions to be executed at a specified frequency.
5  * Things like LED blinking or watchdog triggering are examples for such
6  * tasks.
7  *
8  * Copyright (C) 2022 Stefan Roese <sr@denx.de>
9  */
10 
11 #include <command.h>
12 #include <cyclic.h>
13 #include <div64.h>
14 #include <malloc.h>
15 #include <time.h>
16 #include <vsprintf.h>
17 #include <linux/delay.h>
18 #include <linux/kernel.h>
19 
20 struct cyclic_demo_info {
21 	struct cyclic_info cyclic;
22 	uint delay_us;
23 };
24 
cyclic_demo(struct cyclic_info * c)25 static void cyclic_demo(struct cyclic_info *c)
26 {
27 	struct cyclic_demo_info *info = container_of(c, struct cyclic_demo_info, cyclic);
28 
29 	/* Just a small dummy delay here */
30 	udelay(info->delay_us);
31 }
32 
do_cyclic_demo(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])33 static int do_cyclic_demo(struct cmd_tbl *cmdtp, int flag, int argc,
34 			  char *const argv[])
35 {
36 	struct cyclic_demo_info *info;
37 	uint time_ms;
38 
39 	if (argc < 3)
40 		return CMD_RET_USAGE;
41 
42 	info = malloc(sizeof(struct cyclic_demo_info));
43 	if (!info) {
44 		printf("out of memory\n");
45                 return CMD_RET_FAILURE;
46 	}
47 
48 	time_ms = simple_strtoul(argv[1], NULL, 0);
49 	info->delay_us = simple_strtoul(argv[2], NULL, 0);
50 
51 	/* Register demo cyclic function */
52 	cyclic_register(&info->cyclic, cyclic_demo, time_ms * 1000, "cyclic_demo");
53 
54 	printf("Registered function \"%s\" to be executed all %dms\n",
55 	       "cyclic_demo", time_ms);
56 
57 	return 0;
58 }
59 
do_cyclic_list(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])60 static int do_cyclic_list(struct cmd_tbl *cmdtp, int flag, int argc,
61 			  char *const argv[])
62 {
63 	struct cyclic_info *cyclic;
64 	struct hlist_node *tmp;
65 	u64 cnt, freq;
66 
67 	hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list) {
68 		cnt = cyclic->run_cnt * 1000000ULL * 100ULL;
69 		freq = lldiv(cnt, timer_get_us() - cyclic->start_time_us);
70 		printf("function: %s, cpu-time: %lld us, frequency: %lld.%02d times/s\n",
71 		       cyclic->name, cyclic->cpu_time_us,
72 		       lldiv(freq, 100), do_div(freq, 100));
73 	}
74 
75 	return 0;
76 }
77 
78 U_BOOT_LONGHELP(cyclic,
79 	"demo <cycletime_ms> <delay_us> - register cyclic demo function\n"
80 	"cyclic list - list cyclic functions\n");
81 
82 U_BOOT_CMD_WITH_SUBCMDS(cyclic, "Cyclic", cyclic_help_text,
83 	U_BOOT_SUBCMD_MKENT(demo, 3, 1, do_cyclic_demo),
84 	U_BOOT_SUBCMD_MKENT(list, 1, 1, do_cyclic_list));
85