Stefan Roese | 036f89a | 2022-09-02 13:57:48 +0200 | [diff] [blame] | 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 <cyclic.h> |
| 12 | #include <log.h> |
| 13 | #include <malloc.h> |
| 14 | #include <time.h> |
| 15 | #include <linux/errno.h> |
| 16 | #include <linux/list.h> |
| 17 | #include <asm/global_data.h> |
| 18 | |
| 19 | DECLARE_GLOBAL_DATA_PTR; |
| 20 | |
Stefan Roese | 9747363 | 2022-09-02 14:10:45 +0200 | [diff] [blame] | 21 | void hw_watchdog_reset(void); |
| 22 | |
Stefan Roese | 036f89a | 2022-09-02 13:57:48 +0200 | [diff] [blame] | 23 | struct list_head *cyclic_get_list(void) |
| 24 | { |
| 25 | return &gd->cyclic->cyclic_list; |
| 26 | } |
| 27 | |
| 28 | struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us, |
| 29 | const char *name, void *ctx) |
| 30 | { |
| 31 | struct cyclic_info *cyclic; |
| 32 | |
| 33 | if (!gd->cyclic->cyclic_ready) { |
| 34 | pr_debug("Cyclic IF not ready yet\n"); |
| 35 | return NULL; |
| 36 | } |
| 37 | |
| 38 | cyclic = calloc(1, sizeof(struct cyclic_info)); |
| 39 | if (!cyclic) { |
| 40 | pr_debug("Memory allocation error\n"); |
| 41 | return NULL; |
| 42 | } |
| 43 | |
| 44 | /* Store values in struct */ |
| 45 | cyclic->func = func; |
| 46 | cyclic->ctx = ctx; |
| 47 | cyclic->name = strdup(name); |
| 48 | cyclic->delay_us = delay_us; |
| 49 | cyclic->start_time_us = timer_get_us(); |
| 50 | list_add_tail(&cyclic->list, &gd->cyclic->cyclic_list); |
| 51 | |
| 52 | return cyclic; |
| 53 | } |
| 54 | |
| 55 | int cyclic_unregister(struct cyclic_info *cyclic) |
| 56 | { |
| 57 | list_del(&cyclic->list); |
| 58 | free(cyclic); |
| 59 | |
| 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | void cyclic_run(void) |
| 64 | { |
| 65 | struct cyclic_info *cyclic, *tmp; |
| 66 | uint64_t now, cpu_time; |
| 67 | |
| 68 | /* Prevent recursion */ |
| 69 | if (gd->cyclic->cyclic_running) |
| 70 | return; |
| 71 | |
| 72 | gd->cyclic->cyclic_running = true; |
| 73 | list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list) { |
| 74 | /* |
| 75 | * Check if this cyclic function needs to get called, e.g. |
| 76 | * do not call the cyclic func too often |
| 77 | */ |
| 78 | now = timer_get_us(); |
| 79 | if (time_after_eq64(now, cyclic->next_call)) { |
| 80 | /* Call cyclic function and account it's cpu-time */ |
| 81 | cyclic->next_call = now + cyclic->delay_us; |
| 82 | cyclic->func(cyclic->ctx); |
| 83 | cyclic->run_cnt++; |
| 84 | cpu_time = timer_get_us() - now; |
| 85 | cyclic->cpu_time_us += cpu_time; |
| 86 | |
| 87 | /* Check if cpu-time exceeds max allowed time */ |
| 88 | if (cpu_time > CONFIG_CYCLIC_MAX_CPU_TIME_US) { |
| 89 | pr_err("cyclic function %s took too long: %lldus vs %dus max, disabling\n", |
| 90 | cyclic->name, cpu_time, |
| 91 | CONFIG_CYCLIC_MAX_CPU_TIME_US); |
| 92 | |
| 93 | /* Unregister this cyclic function */ |
| 94 | cyclic_unregister(cyclic); |
| 95 | } |
| 96 | } |
| 97 | } |
| 98 | gd->cyclic->cyclic_running = false; |
| 99 | } |
| 100 | |
Stefan Roese | 9747363 | 2022-09-02 14:10:45 +0200 | [diff] [blame] | 101 | void schedule(void) |
| 102 | { |
| 103 | /* The HW watchdog is not integrated into the cyclic IF (yet) */ |
| 104 | if (IS_ENABLED(CONFIG_HW_WATCHDOG)) |
| 105 | hw_watchdog_reset(); |
| 106 | |
| 107 | /* |
| 108 | * schedule() might get called very early before the cyclic IF is |
| 109 | * ready. Make sure to only call cyclic_run() when it's initalized. |
| 110 | */ |
| 111 | if (gd && gd->cyclic && gd->cyclic->cyclic_ready) |
| 112 | cyclic_run(); |
| 113 | } |
| 114 | |
Stefan Roese | 036f89a | 2022-09-02 13:57:48 +0200 | [diff] [blame] | 115 | int cyclic_uninit(void) |
| 116 | { |
| 117 | struct cyclic_info *cyclic, *tmp; |
| 118 | |
| 119 | list_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list) |
| 120 | cyclic_unregister(cyclic); |
| 121 | gd->cyclic->cyclic_ready = false; |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | int cyclic_init(void) |
| 127 | { |
| 128 | int size = sizeof(struct cyclic_drv); |
| 129 | |
| 130 | gd->cyclic = (struct cyclic_drv *)malloc(size); |
| 131 | if (!gd->cyclic) |
| 132 | return -ENOMEM; |
| 133 | |
| 134 | memset(gd->cyclic, '\0', size); |
| 135 | INIT_LIST_HEAD(&gd->cyclic->cyclic_list); |
| 136 | gd->cyclic->cyclic_ready = true; |
| 137 | |
| 138 | return 0; |
| 139 | } |