esp-idf/components/driver/include/driver/gptimer.h

/*
 * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <stdint.h>
#include <stdbool.h>
#include "esp_err.h"
#include "hal/timer_types.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Type of General Purpose Timer handle
 */
typedef struct gptimer_t *gptimer_handle_t;

/**
 * @brief GPTimer alarm event data
 */
typedef struct {
    uint64_t count_value; /*!< Current count value */
    uint64_t alarm_value; /*!< Current alarm value */
} gptimer_alarm_event_data_t;

/**
 * @brief Timer alarm callback prototype
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @param[in] edata Alarm event data, fed by driver
 * @param[in] user_ctx User data, passed from `gptimer_register_event_callbacks()`
 * @return Whether a high priority task has been waken up by this function
 */
typedef bool (*gptimer_alarm_cb_t) (gptimer_handle_t timer, const gptimer_alarm_event_data_t *edata, void *user_ctx);

/**
 * @brief Group of supported GPTimer callbacks
 * @note The callbacks are all running under ISR environment
 */
typedef struct {
    gptimer_alarm_cb_t on_alarm; /*!< Timer alarm callback */
} gptimer_event_callbacks_t;

/**
 * @brief General Purpose Timer configuration
 */
typedef struct {
    gptimer_clock_source_t clk_src;      /*!< GPTimer clock source */
    gptimer_count_direction_t direction; /*!< Count direction */
    uint32_t resolution_hz;              /*!< Counter resolution (working frequency) in Hz,
                                              hence, the step size of each count tick equals to (1 / resolution_hz) seconds */
    struct {
        uint32_t intr_shared: 1;         /*!< Set true, the timer interrupt number can be shared with other peripherals */
    } flags;
} gptimer_config_t;

/**
 * @brief General Purpose Timer alarm configuration
 */
typedef struct {
    uint64_t alarm_count;  /*!< Alarm target count value */
    uint64_t reload_count; /*!< Alarm reload count value, effect only when `auto_reload_on_alarm` is set to true */
    struct {
        uint32_t auto_reload_on_alarm: 1; /*!< Reload the count value by hardware, immediately at the alarm event */
    } flags;
} gptimer_alarm_config_t;

/**
 * @brief Create a new General Purpose Timer, and return the handle
 *
 * @note Once a timer is created, it is placed in the stopped state and will not start until `gptimer_start()` is called.
 *
 * @param[in] config GPTimer configuration
 * @param[out] ret_timer Returned timer handle
 * @return
 *      - ESP_OK: Create GPTimer successfully
 *      - ESP_ERR_INVALID_ARG: Create GPTimer failed because of invalid argument
 *      - ESP_ERR_NO_MEM: Create GPTimer failed because out of memory
 *      - ESP_ERR_NOT_FOUND: Create GPTimer failed because all hardware timers are used up and no more free one
 *      - ESP_FAIL: Create GPTimer failed because of other error
 */
esp_err_t gptimer_new_timer(const gptimer_config_t *config, gptimer_handle_t *ret_timer);

/**
 * @brief Delete the GPTimer handle
 *
 * @note A timer must be in a stop state before it can be deleted.
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @return
 *      - ESP_OK: Delete GPTimer successfully
 *      - ESP_ERR_INVALID_ARG: Delete GPTimer failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Delete GPTimer failed because the timer has not stopped
 *      - ESP_FAIL: Delete GPTimer failed because of other error
 */
esp_err_t gptimer_del_timer(gptimer_handle_t timer);

/**
 * @brief Set GPTimer raw count value
 *
 * @note When updating the raw count of an active timer, the timer will immediately start counting from the new value.
 * @note This function is allowed to run within ISR context
 * @note This function is allowed to be executed when Cache is disabled, by enabling `CONFIG_GPTIMER_CTRL_FUNC_IN_IRAM`
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @param[in] value Count value to be set
 * @return
 *      - ESP_OK: Set GPTimer raw count value successfully
 *      - ESP_ERR_INVALID_ARG: Set GPTimer raw count value failed because of invalid argument
 *      - ESP_FAIL: Set GPTimer raw count value failed because of other error
 */
esp_err_t gptimer_set_raw_count(gptimer_handle_t timer, uint64_t value);

/**
 * @brief Get GPTimer raw count value
 *
 * @note With the raw count value and the resolution set in the `gptimer_config_t`, you can convert the count value into seconds.
 * @note This function is allowed to run within ISR context
 * @note This function is allowed to be executed when Cache is disabled, by enabling `CONFIG_GPTIMER_CTRL_FUNC_IN_IRAM`
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @param[out] value Returned GPTimer count value
 * @return
 *      - ESP_OK: Get GPTimer raw count value successfully
 *      - ESP_ERR_INVALID_ARG: Get GPTimer raw count value failed because of invalid argument
 *      - ESP_FAIL: Get GPTimer raw count value failed because of other error
 */
esp_err_t gptimer_get_raw_count(gptimer_handle_t timer, uint64_t *value);

/**
 * @brief Set callbacks for GPTimer
 *
 * @note The user registered callbacks are expected to be runnable within ISR context
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @param[in] cbs Group of callback functions
 * @param[in] user_data User data, which will be passed to callback functions directly
 * @return
 *      - ESP_OK: Set event callbacks successfully
 *      - ESP_ERR_INVALID_ARG: Set event callbacks failed because of invalid argument
 *      - ESP_FAIL: Set event callbacks failed because of other error
 */
esp_err_t gptimer_register_event_callbacks(gptimer_handle_t timer, const gptimer_event_callbacks_t *cbs, void *user_data);

/**
 * @brief Set alarm event actions for GPTimer.
 *
 * @note This function is allowed to run within ISR context
 * @note This function is allowed to be executed when Cache is disabled, by enabling `CONFIG_GPTIMER_CTRL_FUNC_IN_IRAM`
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @param[in] config Alarm configuration, especially, set config to NULL means disabling the alarm function
 * @return
 *      - ESP_OK: Set alarm action for GPTimer successfully
 *      - ESP_ERR_INVALID_ARG: Set alarm action for GPTimer failed because of invalid argument
 *      - ESP_FAIL: Set alarm action for GPTimer failed because of other error
 */
esp_err_t gptimer_set_alarm_action(gptimer_handle_t timer, const gptimer_alarm_config_t *config);

/**
 * @brief Start GPTimer
 *
 * @note This function is allowed to run within ISR context
 * @note This function is allowed to be executed when Cache is disabled, by enabling `CONFIG_GPTIMER_CTRL_FUNC_IN_IRAM`
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @return
 *      - ESP_OK: Start GPTimer successfully
 *      - ESP_ERR_INVALID_ARG: Start GPTimer failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Start GPTimer failed because the timer is not in stop state
 *      - ESP_FAIL: Start GPTimer failed because of other error
 */
esp_err_t gptimer_start(gptimer_handle_t timer);

/**
 * @brief Stop GPTimer
 *
 * @note This function is allowed to run within ISR context
 * @note This function is allowed to be executed when Cache is disabled, by enabling `CONFIG_GPTIMER_CTRL_FUNC_IN_IRAM`
 *
 * @param[in] timer Timer handle created by `gptimer_new_timer()`
 * @return
 *      - ESP_OK: Stop GPTimer successfully
 *      - ESP_ERR_INVALID_ARG: Stop GPTimer failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Stop GPTimer failed because the timer is not in start state
 *      - ESP_FAIL: Stop GPTimer failed because of other error
 */
esp_err_t gptimer_stop(gptimer_handle_t timer);

#ifdef __cplusplus
}
#endif