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