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"Das U-Boot" Source Tree
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
20struct cyclic_demo_info {
21 struct cyclic_info cyclic;
22 uint delay_us;
23};
24
25static 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
33static 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
60static 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
78U_BOOT_LONGHELP(cyclic,
79 "demo <cycletime_ms> <delay_us> - register cyclic demo function\n"
80 "cyclic list - list cyclic functions\n");
81
82U_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));