/*
    FreeRTOS V8.2.1 - Copyright (C) 2015 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

    ***************************************************************************
    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
    ***************************************************************************

    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
    the FAQ page "My application does not run, what could be wrong?".  Have you
    defined configASSERT()?

    http://www.FreeRTOS.org/support - In return for receiving this top quality
    embedded software for free we request you assist our global community by
    participating in the support forum.

    http://www.FreeRTOS.org/training - Investing in training allows your team to
    be as productive as possible as early as possible.  Now you can receive
    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
    Ltd, and the world's leading authority on the world's leading RTOS.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "app_util.h"

#ifdef SOFTDEVICE_PRESENT
#include "nrf_soc.h"
#include "softdevice_handler.h"
#include "app_error.h"
#include "app_util_platform.h"
#endif

/*-----------------------------------------------------------
 * Implementation of functions defined in portable.h for the ARM CM4F port.
 * CMSIS compatible layer to menage SysTick ticking source.
 *----------------------------------------------------------*/

#if configTICK_SOURCE == FREERTOS_USE_SYSTICK


#ifndef configSYSTICK_CLOCK_HZ
    #define configSYSTICK_CLOCK_HZ configCPU_CLOCK_HZ
    /* Ensure the SysTick is clocked at the same frequency as the core. */
    #define portNVIC_SYSTICK_CLK_BIT    ( SysTick_CTRL_CLKSOURCE_Msk )
#else
    /* The way the SysTick is clocked is not modified in case it is not the same
    as the core. */
    #define portNVIC_SYSTICK_CLK_BIT    ( 0 )
#endif


#if configUSE_TICKLESS_IDLE == 1
    #error SysTick port for RF52 does not support tickless idle. Use RTC mode instead.
#endif /* configUSE_TICKLESS_IDLE */

/*-----------------------------------------------------------*/

void xPortSysTickHandler( void )
{
    /* The SysTick runs at the lowest interrupt priority, so when this interrupt
    executes all interrupts must be unmasked.  There is therefore no need to
    save and then restore the interrupt mask value as its value is already
    known. */
    ( void ) portSET_INTERRUPT_MASK_FROM_ISR();
    {
        /* Increment the RTOS tick. */
        if ( xTaskIncrementTick() != pdFALSE )
        {
            /* A context switch is required.  Context switching is performed in
            the PendSV interrupt.  Pend the PendSV interrupt. */
            SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
            __SEV();
        }
    }
    portCLEAR_INTERRUPT_MASK_FROM_ISR( 0 );
}

/*-----------------------------------------------------------*/

/*
 * Setup the systick timer to generate the tick interrupts at the required
 * frequency.
 */
void vPortSetupTimerInterrupt( void )
{
    /* Set interrupt priority */
    NVIC_SetPriority(SysTick_IRQn, configKERNEL_INTERRUPT_PRIORITY);
    /* Configure SysTick to interrupt at the requested rate. */
    SysTick->LOAD = ROUNDED_DIV(configSYSTICK_CLOCK_HZ, configTICK_RATE_HZ) - 1UL;
    SysTick->CTRL = ( portNVIC_SYSTICK_CLK_BIT | SysTick_CTRL_TICKINT_Msk | SysTick_CTRL_ENABLE_Msk );
}

/*-----------------------------------------------------------*/

#elif configTICK_SOURCE == FREERTOS_USE_RTC

#if configUSE_16_BIT_TICKS == 1
#error This port does not support 16 bit ticks.
#endif

#include "nrf_rtc.h"
#include "nrf_drv_clock.h"


/*-----------------------------------------------------------*/

void xPortSysTickHandler( void )
{
    nrf_rtc_event_clear(portNRF_RTC_REG, NRF_RTC_EVENT_TICK);
#if configUSE_TICKLESS_IDLE == 1
    nrf_rtc_event_clear(portNRF_RTC_REG, NRF_RTC_EVENT_COMPARE_0);
#endif

    /* The SysTick runs at the lowest interrupt priority, so when this interrupt
    executes all interrupts must be unmasked.  There is therefore no need to
    save and then restore the interrupt mask value as its value is already
    known. */
    ( void ) portSET_INTERRUPT_MASK_FROM_ISR();
    /* Increment the RTOS tick. */
    if ( xTaskIncrementTick() != pdFALSE )
    {
        /* A context switch is required.  Context switching is performed in
        the PendSV interrupt.  Pend the PendSV interrupt. */
        SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
        __SEV();
    }
    portCLEAR_INTERRUPT_MASK_FROM_ISR( 0 );
}

/*
 * Setup the RTC time to generate the tick interrupts at the required
 * frequency.
 */
void vPortSetupTimerInterrupt( void )
{
    /* Request LF clock */
    nrf_drv_clock_lfclk_request(NULL);

    /* Configure SysTick to interrupt at the requested rate. */
    nrf_rtc_prescaler_set(portNRF_RTC_REG, portNRF_RTC_PRESCALER);
    nrf_rtc_int_enable   (portNRF_RTC_REG, RTC_INTENSET_TICK_Msk);
    nrf_rtc_task_trigger (portNRF_RTC_REG, NRF_RTC_TASK_CLEAR);
    nrf_rtc_task_trigger (portNRF_RTC_REG, NRF_RTC_TASK_START);

    NVIC_SetPriority(portNRF_RTC_IRQn, configKERNEL_INTERRUPT_PRIORITY);
    NVIC_EnableIRQ(portNRF_RTC_IRQn);
}

#if configUSE_TICKLESS_IDLE == 1

void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )
{
    /*
     * Implementation note:
     *
     * To help debugging the option configUSE_TICKLESS_IDLE_SIMPLE_DEBUG was presented.
     * This option would make sure that even if program execution was stopped inside
     * this function no more than expected number of ticks would be skipped.
     *
     * Normally RTC works all the time even if firmware execution was stopped
     * and that may lead to skipping too much of ticks.
     */
    TickType_t enterTime;

    /* Make sure the SysTick reload value does not overflow the counter. */
    if ( xExpectedIdleTime > portNRF_RTC_MAXTICKS - configEXPECTED_IDLE_TIME_BEFORE_SLEEP )
    {
        xExpectedIdleTime = portNRF_RTC_MAXTICKS - configEXPECTED_IDLE_TIME_BEFORE_SLEEP;
    }
    /* Block all the interrupts globally */
#ifdef SOFTDEVICE_PRESENT
    do{
        uint8_t dummy = 0;
        uint32_t err_code = sd_nvic_critical_region_enter(&dummy);
        APP_ERROR_CHECK(err_code);
    }while(0);
#else
    __disable_irq();
#endif

    enterTime = nrf_rtc_counter_get(portNRF_RTC_REG);

    if ( eTaskConfirmSleepModeStatus() != eAbortSleep )
    {
        TickType_t xModifiableIdleTime;
        TickType_t wakeupTime = (enterTime + xExpectedIdleTime) & portNRF_RTC_MAXTICKS;

        /* Stop tick events */
        nrf_rtc_int_disable(portNRF_RTC_REG, NRF_RTC_INT_TICK_MASK);

        /* Configure CTC interrupt */
        nrf_rtc_cc_set(portNRF_RTC_REG, 0, wakeupTime);
        nrf_rtc_event_clear(portNRF_RTC_REG, NRF_RTC_EVENT_COMPARE_0);
        nrf_rtc_int_enable(portNRF_RTC_REG, NRF_RTC_INT_COMPARE0_MASK);

        __DSB();

        /* Sleep until something happens.  configPRE_SLEEP_PROCESSING() can
         * set its parameter to 0 to indicate that its implementation contains
         * its own wait for interrupt or wait for event instruction, and so wfi
         * should not be executed again.  However, the original expected idle
         * time variable must remain unmodified, so a copy is taken. */
        xModifiableIdleTime = xExpectedIdleTime;
        configPRE_SLEEP_PROCESSING( xModifiableIdleTime );
        if ( xModifiableIdleTime > 0 )
        {
            do{
                __WFE();
            } while (0 == (NVIC->ISPR[0] | NVIC->ISPR[1]));
        }
        configPOST_SLEEP_PROCESSING( xExpectedIdleTime );
        nrf_rtc_int_disable(portNRF_RTC_REG, NRF_RTC_INT_COMPARE0_MASK);

        /* Correct the system ticks */
        {
            TickType_t diff;
            TickType_t hwTicks     = nrf_rtc_counter_get(portNRF_RTC_REG);

            nrf_rtc_event_clear(portNRF_RTC_REG, NRF_RTC_EVENT_TICK);
            nrf_rtc_int_enable (portNRF_RTC_REG, NRF_RTC_INT_TICK_MASK);

            if(enterTime > hwTicks)
            {
                hwTicks += portNRF_RTC_MAXTICKS + 1U;
            }

            diff = (hwTicks - enterTime);
            if((configUSE_TICKLESS_IDLE_SIMPLE_DEBUG) && (diff > xExpectedIdleTime))
            {
                diff = xExpectedIdleTime;
            }

            if (diff > 0)
            {
                vTaskStepTick(diff);
            }
        }
    }
#ifdef SOFTDEVICE_PRESENT
    uint32_t err_code = sd_nvic_critical_region_exit(0);
    APP_ERROR_CHECK(err_code);
#else
    __enable_irq();
#endif
}

#endif // configUSE_TICKLESS_IDLE

#else // configTICK_SOURCE
    #error  Unsupported configTICK_SOURCE value
#endif // configTICK_SOURCE == FREERTOS_USE_SYSTICK
