cmd/cyclic.c

   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 <common.h>
  12 #include <command.h>
  13 #include <cyclic.h>
  14 #include <div64.h>
  15 #include <malloc.h>
  16 #include <linux/delay.h>
  17
  18 struct cyclic_demo_info {
  19         uint delay_us;
  20 };
  21
  22 static void cyclic_demo(void *ctx)
  23 {
  24         struct cyclic_demo_info *info = ctx;
  25
  26         /* Just a small dummy delay here */
  27         udelay(info->delay_us);
  28 }
  29
  30 static int do_cyclic_demo(struct cmd_tbl *cmdtp, int flag, int argc,
  31                           char *const argv[])
  32 {
  33         struct cyclic_demo_info *info;
  34         struct cyclic_info *cyclic;
  35         uint time_ms;
  36
  37         if (argc < 3)
  38                 return CMD_RET_USAGE;
  39
  40         info = malloc(sizeof(struct cyclic_demo_info));
  41         if (!info) {
  42                 printf("out of memory\n");
  43                 return CMD_RET_FAILURE;
  44         }
  45
  46         time_ms = simple_strtoul(argv[1], NULL, 0);
  47         info->delay_us = simple_strtoul(argv[2], NULL, 0);
  48
  49         /* Register demo cyclic function */
  50         cyclic = cyclic_register(cyclic_demo, time_ms * 1000, "cyclic_demo",
  51                                  info);
  52         if (!cyclic)
  53                 printf("Registering of cyclic_demo failed\n");
  54
  55         printf("Registered function \"%s\" to be executed all %dms\n",
  56                "cyclic_demo", time_ms);
  57
  58         return 0;
  59 }
  60
  61 static int do_cyclic_list(struct cmd_tbl *cmdtp, int flag, int argc,
  62                           char *const argv[])
  63 {
  64         struct cyclic_info *cyclic;
  65         struct hlist_node *tmp;
  66         u64 cnt, freq;
  67
  68         hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list) {
  69                 cnt = cyclic->run_cnt * 1000000ULL * 100ULL;
  70                 freq = lldiv(cnt, timer_get_us() - cyclic->start_time_us);
  71                 printf("function: %s, cpu-time: %lld us, frequency: %lld.%02d times/s\n",
  72                        cyclic->name, cyclic->cpu_time_us,
  73                        lldiv(freq, 100), do_div(freq, 100));
  74         }
  75
  76         return 0;
  77 }
  78
  79 static char cyclic_help_text[] =
  80         "demo <cycletime_ms> <delay_us> - register cyclic demo function\n"
  81         "cyclic list - list cyclic functions\n";
  82
  83 U_BOOT_CMD_WITH_SUBCMDS(cyclic, "Cyclic", cyclic_help_text,
  84         U_BOOT_SUBCMD_MKENT(demo, 3, 1, do_cyclic_demo),
  85         U_BOOT_SUBCMD_MKENT(list, 1, 1, do_cyclic_list));