third_party/NordicSemiconductor/drivers/radio/rsch/nrf_802154_rsch.h

/* Copyright (c) 2018, Nordic Semiconductor ASA
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 *   3. Neither the name of Nordic Semiconductor ASA nor the names of its
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 *      this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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/**
 * @brief Module that defines the Radio Scheduler interface.
 *
 */

#ifndef NRF_802154_RSCH_H_
#define NRF_802154_RSCH_H_

#include <stdbool.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup nrf_rsch Radio Scheduler
 * @{
 * @ingroup nrf_802154
 * @brief The Radio Scheduler interface.
 *
 * Radio Scheduler is responsible to schedule radio activities and preconditions in time. It is
 * expected that the Radio Scheduler module manages timings to meet the requirements requested from
 * the core module.
 *
 * Examples of the radio activity preconditions are: High-Frequency Clock running, radio arbiter (RAAL)
 * granted access to the RADIO peripheral.
 */

/**
 * @brief List of the preconditions that have to be met before any radio activity.
 */
typedef enum
{
    RSCH_PREC_HFCLK,
    RSCH_PREC_RAAL,
    RSCH_PREC_CNT,
} rsch_prec_t;

/**
 * @brief Priorities of the 802.15.4 radio operations.
 */
typedef enum
{
    RSCH_PRIO_IDLE,                                    ///< Priority used in the sleep state. With this priority, RSCH releases all preconditions.
    RSCH_PRIO_IDLE_LISTENING,                          ///< Priority used during the idle listening procedure.
    RSCH_PRIO_RX,                                      ///< Priority used when a frame is being received.
    RSCH_PRIO_DETECT,                                  ///< Priority used to detect channel conditions (CCA, ED).
    RSCH_PRIO_TX,                                      ///< Priority used to transmit a frame.

    RSCH_PRIO_MIN_APPROVED = RSCH_PRIO_IDLE_LISTENING, ///< Minimal priority indicating that the given precondition is approved.
    RSCH_PRIO_MAX          = RSCH_PRIO_TX,             ///< Maximal priority available in the RSCH module.
} rsch_prio_t;

/**
 * @brief Enumeration of the delayed timeslot IDs.
 */
typedef enum
{
    RSCH_DLY_TX,     ///< Timeslot for delayed TX operation.
    RSCH_DLY_RX,     ///< Timeslot for delayed RX operation.

    RSCH_DLY_TS_NUM, ///< Number of delayed timeslots.
} rsch_dly_ts_id_t;

/**
 * @brief Initializes Radio Scheduler.
 *
 * @note This function must be called once, before any other function from this module.
 *
 * @note Radio Scheduler starts in the inactive mode after the initialization. To start the radio activity,
 *       @ref nrf_802154_rsch_continuous_mode_enter should be called.
 *
 */
void nrf_802154_rsch_init(void);

/**
 * @brief Deinitializes Radio Scheduler.
 *
 */
void nrf_802154_rsch_uninit(void);

/**
 * @brief Sets the priority for the continuous radio mode.
 *
 * In the continuous mode, Radio Scheduler tries to satisfy all preconditions for as long as
 * possible to give the radio driver core as much radio time as possible while
 * disturbing the other activities to the minimum extent.
 *
 * @note The start of a timeslot is indicated by the @ref nrf_802154_rsch_prec_approved call.
 * @note To disable the continuous radio mode, the @ref RSCH_PRIO_IDLE should be used.
 *
 * @param[in]  prio  Priority level used in the continuous radio mode.
 *
 */
void nrf_802154_rsch_continuous_mode_priority_set(rsch_prio_t prio);

/**
 * @brief Confirms that the current part of the continuous timeslot is ended by the core.
 *
 * This confirmation is used by the core to synchronize the ending of the continuous timeslot parts with
 * the RSCH module.
 *
 */
void nrf_802154_rsch_continuous_ended(void);

/**
 * @brief Immediately requests a timeslot for radio communication.
 *
 * This function is to be called only after @ref nrf_802154_rsch_prec_approved indicated the
 * start of a timeslot.
 *
 * @param[in] length_us  Requested radio timeslot length in microseconds.
 *
 * @retval true   Radio driver has now exclusive access to the RADIO peripheral for the
 *                full length of the timeslot.
 * @retval false  Slot cannot be assigned due to other activities.
 *
 */
bool nrf_802154_rsch_timeslot_request(uint32_t length_us);

/**
 * @brief Requests a timeslot in the future.
 *
 * Request timeslot that is to be granted in the future. The function parameters provide data when
 * the timeslot is supposed to start and how long it is to last. When the requested timeslot starts,
 * @ref nrf_802154_rsch_delayed_timeslot_started is called.
 *
 * @note @ref nrf_802154_rsch_delayed_timeslot_started can be delayed and it is up to
 *       the called module to check the delay and decide if it causes any issues.
 *
 * @note The time parameters use the same units that are used in the Timer Scheduler module.
 *
 * @param[in]  t0      Base time of the timestamp of the timeslot start, in microseconds.
 * @param[in]  dt      Time delta between @p t0 and the timestamp of the timeslot start, in microseconds.
 * @param[in]  length  Requested radio timeslot length, in microseconds.
 * @param[in]  prio    Priority level required for the delayed timeslot.
 * @param[in]  dly_ts  Type of the requested timeslot.
 *
 * @retval true   Requested timeslot has been scheduled.
 * @retval false  Requested timeslot cannot be scheduled and will not be granted.
 */
bool nrf_802154_rsch_delayed_timeslot_request(uint32_t         t0,
                                              uint32_t         dt,
                                              uint32_t         length,
                                              rsch_prio_t      prio,
                                              rsch_dly_ts_id_t dly_ts);

/**
 * @brief Cancels a requested future timeslot.
 *
 * @param[in] dly_ts_id     Type of the requested timeslot.
 *
 * @retval true     Scheduled timeslot has been cancelled.
 * @retval false    No scheduled timeslot has been requested (nothing to cancel).
 */
bool nrf_802154_rsch_delayed_timeslot_cancel(rsch_dly_ts_id_t dly_ts_id);

/**
 * @brief Checks if there is a pending timeslot request.
 *
 * @note The delayed timeslot is considered requested once its preconditions are requested
 *       or granted.
 *
 * @retval true   There is a timeslot request pending.
 * @retval false  There are no pending timeslot requests.
 */
bool nrf_802154_rsch_timeslot_is_requested(void);

/**
 * @brief Checks if the RSCH precondition is satisfied.
 *
 * @param[in]  prec    RSCH precondition to be checked.
 * @param[in]  prio    Minimal required priority level of the given precondition.
 *
 * @retval true   Precondition @p prec is currently granted.
 * @retval false  Precondition @p prec is not currently granted.
 */
bool nrf_802154_rsch_prec_is_approved(rsch_prec_t prec, rsch_prio_t prio);

/**
 * @brief Gets the remaining time of the currently granted timeslot, in microseconds.
 *
 * @returns  Number of microseconds remaining in the currently granted timeslot.
 */
uint32_t nrf_802154_rsch_timeslot_us_left_get(void);

/**
 * @brief Notifies the core about changes of the approved priority level.
 *
 * If @p prio is greater than @ref RSCH_PRIO_IDLE, the radio driver has exclusive access to the
 * peripherals until this function is called with @p prio equal to @ref RSCH_PRIO_IDLE.
 *
 * @note The end of the timeslot is indicated by @p prio equal to @ref RSCH_PRIO_IDLE.
 *
 * @param[in]  prio  Currently approved priority level.
 */
extern void nrf_802154_rsch_continuous_prio_changed(rsch_prio_t prio);

/**
 * @brief Notifies that the previously requested delayed timeslot has started just now.
 *
 * @param[in]  dly_ts_id  Type of the started timeslot.
 */
extern void nrf_802154_rsch_delayed_timeslot_started(rsch_dly_ts_id_t dly_ts_id);

/**
 *@}
 **/

#ifdef __cplusplus
}
#endif

#endif /* NRF_802154_RSCH_H_ */