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 #include <linux/kernel.h>
  19
  20 struct cyclic_demo_info {
  21         struct cyclic_info cyclic;
  22         uint delay_us;
  23 };
  24
  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
  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
  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));