jcs.org
"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#ifndef __cyclic_h
12#define __cyclic_h
13
14#include <linux/list.h>
15#include <asm/types.h>
16#include <u-boot/schedule.h> // to be removed later
17
18/**
19 * struct cyclic_info - Information about cyclic execution function
20 *
21 * @func: Function to call periodically
22 * @name: Name of the cyclic function, e.g. shown in the commands
23 * @delay_us: Delay is us after which this function shall get executed
24 * @start_time_us: Start time in us, when this function started its execution
25 * @cpu_time_us: Total CPU time of this function
26 * @run_cnt: Counter of executions occurances
27 * @next_call: Next time in us, when the function shall be executed again
28 * @list: List node
29 * @already_warned: Flag that we've warned about exceeding CPU time usage
30 *
31 * When !CONFIG_CYCLIC, this struct is empty.
32 */
33struct cyclic_info {
34#if defined(CONFIG_CYCLIC)
35 void (*func)(struct cyclic_info *c);
36 const char *name;
37 uint64_t delay_us;
38 uint64_t start_time_us;
39 uint64_t cpu_time_us;
40 uint64_t run_cnt;
41 uint64_t next_call;
42 struct hlist_node list;
43 bool already_warned;
44#endif
45};
46
47/** Function type for cyclic functions */
48typedef void (*cyclic_func_t)(struct cyclic_info *c);
49
50#if CONFIG_IS_ENABLED(CYCLIC)
51
52/**
53 * cyclic_register - Register a new cyclic function
54 *
55 * @cyclic: Cyclic info structure
56 * @func: Function to call periodically
57 * @delay_us: Delay is us after which this function shall get executed
58 * @name: Cyclic function name/id
59 *
60 * The function @func will be called with @cyclic as its
61 * argument. @cyclic will usually be embedded in some device-specific
62 * structure, which the callback can retrieve using container_of().
63 */
64void cyclic_register(struct cyclic_info *cyclic, cyclic_func_t func,
65 uint64_t delay_us, const char *name);
66
67/**
68 * cyclic_unregister - Unregister a cyclic function
69 *
70 * @cyclic: Pointer to cyclic_struct of the function that shall be removed
71 */
72void cyclic_unregister(struct cyclic_info *cyclic);
73
74/**
75 * cyclic_unregister_all() - Clean up cyclic functions
76 *
77 * This removes all cyclic functions
78 */
79int cyclic_unregister_all(void);
80
81/**
82 * cyclic_get_list() - Get cyclic list pointer
83 *
84 * Return the cyclic list pointer
85 *
86 * @return: pointer to cyclic_list
87 */
88struct hlist_head *cyclic_get_list(void);
89
90#else
91
92static inline void cyclic_register(struct cyclic_info *cyclic, cyclic_func_t func,
93 uint64_t delay_us, const char *name)
94{
95}
96
97static inline void cyclic_unregister(struct cyclic_info *cyclic)
98{
99}
100
101static inline int cyclic_unregister_all(void)
102{
103 return 0;
104}
105#endif /* CYCLIC */
106
107#endif