third_party/NordicSemiconductor/drivers/radio/platform/hp_timer/nrf_802154_hp_timer.c

/* Copyright (c) 2018, Nordic Semiconductor ASA
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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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/**
 * @file
 *   This file contains implementation of the nRF 802.15.4 high precision timer abstraction.
 *
 * This implementation is built on top of the TIMER peripheral.
 * If SoftDevice RAAL is in use the TIMER peripheral is shared between RAAL and this module.
 *
 */

#include "nrf_802154_hp_timer.h"

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

#include <nrf.h>
#include <nrf_timer.h>

#include "nrf_802154_config.h"

/**@brief Timer instance. */
#define TIMER                 NRF_TIMER0

/**@brief Timer compare channel definitions. */
#define TIMER_CC_CAPTURE      NRF_TIMER_CC_CHANNEL1
#define TIMER_CC_CAPTURE_TASK NRF_TIMER_TASK_CAPTURE1

#define TIMER_CC_SYNC         NRF_TIMER_CC_CHANNEL2
#define TIMER_CC_SYNC_TASK    NRF_TIMER_TASK_CAPTURE2
#define TIMER_CC_SYNC_EVENT   NRF_TIMER_EVENT_COMPARE2
#define TIMER_CC_SYNC_INT     NRF_TIMER_INT_COMPARE2_MASK

#define TIMER_CC_EVT          NRF_TIMER_CC_CHANNEL3
#define TIMER_CC_EVT_TASK     NRF_TIMER_TASK_CAPTURE3
#define TIMER_CC_EVT_INT      NRF_TIMER_INT_COMPARE3_MASK

/**@brief Unexpected value in the sync compare channel. */
static uint32_t m_unexpected_sync;

/**@brief Get current time on the Timer. */
static inline uint32_t timer_time_get(void)
{
    nrf_timer_task_trigger(TIMER, TIMER_CC_CAPTURE_TASK);
    return nrf_timer_cc_read(TIMER, TIMER_CC_CAPTURE);
}

void nrf_802154_hp_timer_init(void)
{
    // Intentionally empty
}

void nrf_802154_hp_timer_deinit(void)
{
    nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_SHUTDOWN);
}

void nrf_802154_hp_timer_start(void)
{
#if !RAAL_SOFTDEVICE && !RAAL_SIMULATOR && !RAAL_REM
    nrf_timer_mode_set(TIMER, NRF_TIMER_MODE_TIMER);
    nrf_timer_bit_width_set(TIMER, NRF_TIMER_BIT_WIDTH_32);
    nrf_timer_frequency_set(TIMER, NRF_TIMER_FREQ_1MHz);
    nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_START);
#endif // !RAAL_SOFTDEVICE && !RAAL_SIMULATOR && !RAAL_REM
}

void nrf_802154_hp_timer_stop(void)
{
#if !RAAL_SOFTDEVICE && !RAAL_SIMULATOR && !RAAL_REM
    nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_SHUTDOWN);
#endif // !RAAL_SOFTDEVICE && !RAAL_SIMULATOR && !RAAL_REM
}

uint32_t nrf_802154_hp_timer_sync_task_get(void)
{
    return (uint32_t)nrf_timer_task_address_get(TIMER, TIMER_CC_SYNC_TASK);
}

void nrf_802154_hp_timer_sync_prepare(void)
{
    uint32_t past_time = timer_time_get() - 1;

    m_unexpected_sync = past_time;
    nrf_timer_cc_write(TIMER, TIMER_CC_SYNC, past_time);
}

bool nrf_802154_hp_timer_sync_time_get(uint32_t * p_timestamp)
{
    bool     result    = false;
    uint32_t sync_time = nrf_timer_cc_read(TIMER, TIMER_CC_SYNC);

    assert(p_timestamp != NULL);

    if (sync_time != m_unexpected_sync)
    {
        *p_timestamp = sync_time;
        result       = true;
    }

    return result;
}

uint32_t nrf_802154_hp_timer_timestamp_task_get(void)
{
    return (uint32_t)nrf_timer_task_address_get(TIMER, TIMER_CC_EVT_TASK);
}

uint32_t nrf_802154_hp_timer_timestamp_get(void)
{
    return nrf_timer_cc_read(TIMER, TIMER_CC_EVT);
}