/*
* SPDX-FileCopyrightText: 2017-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
/**
* @file esp_timer.h
* @brief microsecond-precision 64-bit timer API, replacement for ets_timer
*
* esp_timer APIs allow components to receive callbacks when a hardware timer
* reaches certain value. The timer provides microsecond accuracy and
* up to 64 bit range. Note that while the timer itself provides microsecond
* accuracy, callbacks are dispatched from an auxiliary task. Some time is
* needed to notify this task from timer ISR, and then to invoke the callback.
* If more than one callback needs to be dispatched at any particular time,
* each subsequent callback will be dispatched only when the previous callback
* returns. Therefore, callbacks should not do much work; instead, they should
* use RTOS notification mechanisms (queues, semaphores, event groups, etc.) to
* pass information to other tasks.
*
* To be implemented: it should be possible to request the callback to be called
* directly from the ISR. This reduces the latency, but has potential impact on
* all other callbacks which need to be dispatched. This option should only be
* used for simple callback functions, which do not take longer than a few
* microseconds to run.
*
* Timer callbacks are called from a task running on CPU0.
* On chips with multiple cores, CPU0 (default) can be changed using
* the Kconfig option CONFIG_ESP_TIMER_TASK_AFFINITY.
*/
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include "esp_err.h"
#include "esp_etm.h"
#include "sdkconfig.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Opaque type representing a single timer handle
*/
typedef struct esp_timer* esp_timer_handle_t;
/**
* @brief Timer callback function type
* @param arg pointer to opaque user-specific data
*/
typedef void (*esp_timer_cb_t)(void* arg);
/**
* @brief Method to dispatch timer callback
*/
typedef enum {
ESP_TIMER_TASK, //!< Callback is dispatched from esp_timer task
#if CONFIG_ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD || __DOXYGEN__
ESP_TIMER_ISR, //!< Callback is dispatched from interrupt handler
#endif
ESP_TIMER_MAX, //!< Sentinel value for the number of callback dispatch methods
} esp_timer_dispatch_t;
/**
* @brief Timer configuration passed to esp_timer_create()
*/
typedef struct {
esp_timer_cb_t callback; //!< Callback function to execute when timer expires
void* arg; //!< Argument to pass to callback
esp_timer_dispatch_t dispatch_method; //!< Dispatch callback from task or ISR; if not specified, esp_timer task
// !< is used; for ISR to work, also set Kconfig option
// !< `CONFIG_ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD`
const char* name; //!< Timer name, used in esp_timer_dump() function
bool skip_unhandled_events; //!< Setting to skip unhandled events in light sleep for periodic timers
} esp_timer_create_args_t;
/**
* @brief Minimal initialization of esp_timer
*
* @note This function is called from startup code. Applications do not need
* to call this function before using other esp_timer APIs.
*
* This function can be called very early in startup process, after this call
* only esp_timer_get_time() function can be used.
*
* @return
* - ESP_OK on success
*/
esp_err_t esp_timer_early_init(void);
/**
* @brief Initialize esp_timer library
*
* @note This function is called from startup code. Applications do not need
* to call this function before using other esp_timer APIs.
* Before calling this function, esp_timer_early_init() must be called by the
* startup code.
*
* This function will be called from startup code on every core.
* If Kconfig option `CONFIG_ESP_TIMER_ISR_AFFINITY` is set to `NO_AFFINITY`,
* it allocates the timer ISR on MULTIPLE cores and
* creates the timer task which can be run on any core.
*
* @return
* - ESP_OK on success
* - ESP_ERR_NO_MEM if allocation has failed
* - ESP_ERR_INVALID_STATE if already initialized
* - other errors from interrupt allocator
*/
esp_err_t esp_timer_init(void);
/**
* @brief De-initialize esp_timer library
*
* @note Normally this function should not be called from applications
*
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_STATE if not yet initialized
*/
esp_err_t esp_timer_deinit(void);
/**
* @brief Create an esp_timer instance
*
* @note When timer no longer needed, delete it using esp_timer_delete().
*
* @param create_args Pointer to a structure with timer creation arguments.
* Not saved by the library, can be allocated on the stack.
* @param[out] out_handle Output, pointer to esp_timer_handle_t variable that
* holds the created timer handle.
*
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if some of the create_args are not valid
* - ESP_ERR_INVALID_STATE if esp_timer library is not initialized yet
* - ESP_ERR_NO_MEM if memory allocation fails
*/
esp_err_t esp_timer_create(const esp_timer_create_args_t* create_args,
esp_timer_handle_t* out_handle);
/**
* @brief Start a one-shot timer
*
* Timer represented by `timer` should not be running when this function is called.
*
* @param timer timer handle created using esp_timer_create()
* @param timeout_us timer timeout, in microseconds relative to the current moment
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if the handle is invalid
* - ESP_ERR_INVALID_STATE if the timer is already running
*/
esp_err_t esp_timer_start_once(esp_timer_handle_t timer, uint64_t timeout_us);
/**
* @brief Start a periodic timer
*
* Timer represented by `timer` should not be running when this function is called.
* This function starts the timer which will trigger every `period` microseconds.
*
* @param timer timer handle created using esp_timer_create()
* @param period timer period, in microseconds
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if the handle is invalid
* - ESP_ERR_INVALID_STATE if the timer is already running
*/
esp_err_t esp_timer_start_periodic(esp_timer_handle_t timer, uint64_t period);
/**
* @brief Restart a currently running timer
*
* Type of `timer` | Action
* --------------- | ------
* One-shot timer | Restarted immediately and times out once in `timeout_us` microseconds
* Periodic timer | Restarted immediately with a new period of `timeout_us` microseconds
*
* @param timer timer handle created using esp_timer_create()
* @param timeout_us Timeout in microseconds relative to the current time.
* In case of a periodic timer, also represents the new period.
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if the handle is invalid
* - ESP_ERR_INVALID_STATE if the timer is not running
*/
esp_err_t esp_timer_restart(esp_timer_handle_t timer, uint64_t timeout_us);
/**
* @brief Stop a running timer
*
* This function stops the timer previously started using esp_timer_start_once()
* or esp_timer_start_periodic().
*
* @param timer timer handle created using esp_timer_create()
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_STATE if the timer is not running
*/
esp_err_t esp_timer_stop(esp_timer_handle_t timer);
/**
* @brief Delete an esp_timer instance
*
* The timer must be stopped before deleting. A one-shot timer which has expired
* does not need to be stopped.
*
* @param timer timer handle created using esp_timer_create()
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_STATE if the timer is running
*/
esp_err_t esp_timer_delete(esp_timer_handle_t timer);
/**
* @brief Get time in microseconds since boot
* @return Number of microseconds since the initialization of ESP Timer
*/
int64_t esp_timer_get_time(void);
/**
* @brief Get the timestamp of the next expected timeout
* @return Timestamp of the nearest timer event, in microseconds.
* The timebase is the same as for the values returned by esp_timer_get_time().
*/
int64_t esp_timer_get_next_alarm(void);
/**
* @brief Get the timestamp of the next expected timeout excluding those timers
* that should not interrupt light sleep (such timers have
* ::esp_timer_create_args_t::skip_unhandled_events enabled)
* @return Timestamp of the nearest timer event, in microseconds.
* The timebase is the same as for the values returned by esp_timer_get_time().
*/
int64_t esp_timer_get_next_alarm_for_wake_up(void);
/**
* @brief Get the period of a timer
*
* This function fetches the timeout period of a timer.
* For a one-shot timer, the timeout period will be 0.
*
* @param timer timer handle created using esp_timer_create()
* @param period memory to store the timer period value in microseconds
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if the arguments are invalid
*/
esp_err_t esp_timer_get_period(esp_timer_handle_t timer, uint64_t *period);
/**
* @brief Get the expiry time of a one-shot timer
*
* This function fetches the expiry time of a one-shot timer.
*
* @note Passing the timer handle of a periodic timer will result in an error.
*
* @param timer timer handle created using esp_timer_create()
* @param expiry memory to store the timeout value in microseconds
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if the arguments are invalid
* - ESP_ERR_NOT_SUPPORTED if the timer type is periodic
*/
esp_err_t esp_timer_get_expiry_time(esp_timer_handle_t timer, uint64_t *expiry);
/**
* @brief Dump the list of timers to a stream
*
* By default, this function prints the list of active (running) timers. The output format is:
*
* | Name | Period | Alarm |
*
* - Name — timer pointer
* - Period — period of timer in microseconds, or 0 for one-shot timer
* - Alarm - time of the next alarm in microseconds since boot, or 0 if the timer is not started
*
* To print the list of all created timers, enable Kconfig option `CONFIG_ESP_TIMER_PROFILING`.
* In this case, the output format is:
*
* | Name | Period | Alarm | Times_armed | Times_trigg | Times_skip | Cb_exec_time |
*
* - Name — timer name
* - Period — same as above
* - Alarm — same as above
* - Times_armed — number of times the timer was armed via esp_timer_start_X
* - Times_triggered - number of times the callback was triggered
* - Times_skipped - number of times the callback was skipped
* - Callback_exec_time - total time taken by callback to execute, across all calls
*
* @param stream stream (such as stdout) to which to dump the information
* @return
* - ESP_OK on success
* - ESP_ERR_NO_MEM if can not allocate temporary buffer for the output
*/
esp_err_t esp_timer_dump(FILE* stream);
#if CONFIG_ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD || defined __DOXYGEN__
/**
* @brief Requests a context switch from a timer callback function.
*
* This only works for a timer that has an ISR dispatch method.
* The context switch will be called after all ISR dispatch timers have been processed.
*/
void esp_timer_isr_dispatch_need_yield(void);
#endif // CONFIG_ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD || defined __DOXYGEN__
/**
* @brief Returns status of a timer, active or not
*
* This function is used to identify if the timer is still active (running) or not.
*
* @param timer timer handle created using esp_timer_create()
* @return
* - 1 if timer is still active (running)
* - 0 if timer is not active
*/
bool esp_timer_is_active(esp_timer_handle_t timer);
/**
* @brief Get the ETM event handle of esp_timer underlying alarm event
*
* @note The created ETM event object can be deleted later using esp_etm_del_event()
*
* @note The ETM event is generated by the underlying hardware - systimer;
* therefore, if the esp_timer is not clocked by systimer, then no ETM event will be generated.
*
* @param[out] out_event Returned ETM event handle
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Parameter error
*/
esp_err_t esp_timer_new_etm_alarm_event(esp_etm_event_handle_t *out_event);
#ifdef __cplusplus
}
#endif