/*****************************************************************************
* Product: DPP example, STM32 NUCLEO-L152RE board, cooperative QV kernel
* Last Updated for Version: 5.6.5
* Date of the Last Update:  2016-07-05
*
*                    Q u a n t u m     L e a P s
*                    ---------------------------
*                    innovating embedded systems
*
* Copyright (C) Quantum Leaps, LLC. All rights reserved.
*
* This program is open source software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alternatively, this program may be distributed and modified under the
* terms of Quantum Leaps commercial licenses, which expressly supersede
* the GNU General Public License and are specifically designed for
* licensees interested in retaining the proprietary status of their code.
*
* This program 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Contact information:
* https://state-machine.com
* mailto:info@state-machine.com
*****************************************************************************/
#include "qpc.h"
#include "dpp.h"
#include "bsp.h"

#include "stm32l1xx.h"  /* CMSIS-compliant header file for the MCU used */
/* add other drivers if necessary... */

Q_DEFINE_THIS_FILE

/*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CAUTION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
* Assign a priority to EVERY ISR explicitly by calling NVIC_SetPriority().
* DO NOT LEAVE THE ISR PRIORITIES AT THE DEFAULT VALUE!
*/
enum KernelAwareISRs {
    GPIOPORTA_PRIO = QF_AWARE_ISR_CMSIS_PRI, /* see NOTE00 */
    SYSTICK_PRIO,
    /* ... */
    MAX_KERNEL_AWARE_CMSIS_PRI /* keep always last */
};
/* "kernel-aware" interrupts should not overlap the PendSV priority */
Q_ASSERT_COMPILE(MAX_KERNEL_AWARE_CMSIS_PRI <= (0xFF >>(8-__NVIC_PRIO_BITS)));

void SysTick_Handler(void);

/* Local-scope defines -----------------------------------------------------*/
/* LED pins available on the board (just one user LED LD2--Green on PA.5) */
#define LED_LD2  (1U << 5)

/* Button pins available on the board (just one user Button B1 on PC.13) */
#define BTN_B1   (1U << 13)


static uint32_t l_rnd;  /* random seed */

#ifdef Q_SPY
    QSTimeCtr QS_tickTime_;
    QSTimeCtr QS_tickPeriod_;

    /* event-source identifiers used for tracing */
    static uint8_t const l_SysTick_Handler = 0U;

    enum AppRecords { /* application-specific trace records */
        PHILO_STAT = QS_USER
    };

#endif

/* ISRs used in the application ==========================================*/
void SysTick_Handler(void) {   /* system clock tick ISR */
    /* state of the button debouncing, see below */
    static struct ButtonsDebouncing {
        uint32_t depressed;
        uint32_t previous;
    } buttons = { ~0U, ~0U };
    uint32_t current;
    uint32_t tmp;

#ifdef Q_SPY
    {
        tmp = SysTick->CTRL; /* clear CTRL_COUNTFLAG */
        QS_tickTime_ += QS_tickPeriod_; /* account for the clock rollover */
    }
#endif

    QF_TICK_X(0U, &l_SysTick_Handler); /* process time events for rate 0 */

    /* get state of the user button */
    /* Perform the debouncing of buttons. The algorithm for debouncing
    * adapted from the book "Embedded Systems Dictionary" by Jack Ganssle
    * and Michael Barr, page 71.
    */
    current = ~GPIOC->IDR; /* read Port C with the state of Button B1 */
    tmp = buttons.depressed; /* save the debounced depressed buttons */
    buttons.depressed |= (buttons.previous & current); /* set depressed */
    buttons.depressed &= (buttons.previous | current); /* clear released */
    buttons.previous   = current; /* update the history */
    tmp ^= buttons.depressed;     /* changed debounced depressed */
    if ((tmp & BTN_B1) != 0U) {  /* debounced B1 state changed? */
        if ((buttons.depressed & BTN_B1) != 0U) { /* is B1 depressed? */
            static QEvt const pauseEvt = { PAUSE_SIG, 0U, 0U};
            QF_PUBLISH(&pauseEvt, &l_SysTick_Handler);
        }
        else {            /* the button is released */
            static QEvt const serveEvt = { SERVE_SIG, 0U, 0U};
            QF_PUBLISH(&serveEvt, &l_SysTick_Handler);
        }
    }
}

/* BSP functions ===========================================================*/
void BSP_init(void) {
    /* NOTE: SystemInit() has been already called from the startup code
    *  but SystemCoreClock needs to be updated
    */
    SystemCoreClockUpdate();

    /* enable GPIOA clock port for the LED LD2 */
    RCC->AHBENR |= (1U << 0);

    /* configure LED (PA.5) pin as push-pull output, no pull-up, pull-down */
    GPIOA->MODER   &= ~((3U << 2*5));
    GPIOA->MODER   |=  ((1U << 2*5));
    GPIOA->OTYPER  &= ~((1U <<   5));
    GPIOA->OSPEEDR &= ~((3U << 2*5));
    GPIOA->OSPEEDR |=  ((1U << 2*5));
    GPIOA->PUPDR   &= ~((3U << 2*5));

    /* enable GPIOC clock port for the Button B1 */
    RCC->AHBENR |=  (1U << 2);

    /* configure Button (PC.13) pins as input, no pull-up, pull-down */
    GPIOC->MODER   &= ~(3U << 2*13);
    GPIOC->OSPEEDR &= ~(3U << 2*13);
    GPIOC->OSPEEDR |=  (1U << 2*13);
    GPIOC->PUPDR   &= ~(3U << 2*13);

    BSP_randomSeed(1234U); /* seed the random number generator */

    /* initialize the QS software tracing... */
    if (QS_INIT((void *)0) == 0U) {
        Q_ERROR();
    }
    QS_OBJ_DICTIONARY(&l_SysTick_Handler);
}
/*..........................................................................*/
void BSP_displayPhilStat(uint8_t n, char const *stat) {
    if (stat[0] == 'h') {
        GPIOA->BSRRL |= LED_LD2;  /* turn LED on  */
    }
    else {
        GPIOA->BSRRH |= LED_LD2;  /* turn LED off */
    }

    QS_BEGIN(PHILO_STAT, AO_Philo[n]) /* application-specific record begin */
        QS_U8(1, n);                  /* Philosopher number */
        QS_STR(stat);                 /* Philosopher status */
    QS_END()
}
/*..........................................................................*/
void BSP_displayPaused(uint8_t paused) {
    // not enough LEDs to show the "Paused" status
    if (paused != (uint8_t)0) {
        //GPIOA->BSRRL |= LED_LD2;  /* turn LED on  */
    }
    else {
        //GPIOA->BSRRH |= LED_LD2;  /* turn LED off */
    }
}
/*..........................................................................*/
uint32_t BSP_random(void) { /* a very cheap pseudo-random-number generator */
    /* "Super-Duper" Linear Congruential Generator (LCG)
    * LCG(2^32, 3*7*11*13*23, 0, seed)
    */
    l_rnd = l_rnd * (3U*7U*11U*13U*23U);
    return l_rnd >> 8;
}
/*..........................................................................*/
void BSP_randomSeed(uint32_t seed) {
    l_rnd = seed;
}
/*..........................................................................*/
void BSP_terminate(int16_t result) {
    (void)result;
}

/* QF callbacks ============================================================*/
void QF_onStartup(void) {
    /* set up the SysTick timer to fire at BSP_TICKS_PER_SEC rate */
    SysTick_Config(SystemCoreClock / BSP_TICKS_PER_SEC);

    /* set priorities of ALL ISRs used in the system, see NOTE00
    *
    * !!!!!!!!!!!!!!!!!!!!!!!!!!!! CAUTION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    * Assign a priority to EVERY ISR explicitly by calling NVIC_SetPriority().
    * DO NOT LEAVE THE ISR PRIORITIES AT THE DEFAULT VALUE!
    */
    NVIC_SetPriority(SysTick_IRQn,   SYSTICK_PRIO);
    /* ... */

    /* enable IRQs... */
}
/*..........................................................................*/
void QF_onCleanup(void) {
}
/*..........................................................................*/
void QV_onIdle(void) {  /* called with interrupts disabled, see NOTE01 */

    /* toggle an LED on and then off (not enough LEDs, see NOTE02) */
    QF_INT_DISABLE();
    //GPIOA->BSRRL |= LED_LD2;  /* turn LED[n] on  */
    //GPIOA->BSRRH |= LED_LD2;  /* turn LED[n] off */
    QF_INT_ENABLE();

#ifdef Q_SPY
    if ((USART2->SR & 0x0080U) != 0) {  /* is TXE empty? */
        uint16_t b;

        QF_INT_DISABLE();
        b = QS_getByte();
        QF_INT_ENABLE();

        if (b != QS_EOD) {  /* not End-Of-Data? */
            USART2->DR  = (b & 0xFFU);  /* put into the DR register */
        }
    }
#elif defined NDEBUG
    /* Put the CPU and peripherals to the low-power mode.
    * you might need to customize the clock management for your application,
    * see the datasheet for your particular Cortex-M3 MCU.
    */
    /* !!!CAUTION!!!
    * The WFI instruction stops the CPU clock, which unfortunately disables
    * the JTAG port, so the ST-Link debugger can no longer connect to the
    * board. For that reason, the call to __WFI() has to be used with CAUTION.
    *
    * NOTE: If you find your board "frozen" like this, strap BOOT0 to VDD and
    * reset the board, then connect with ST-Link Utilities and erase the part.
    * The trick with BOOT(0) is it gets the part to run the System Loader
    * instead of your broken code. When done disconnect BOOT0, and start over.
    */
    //QV_CPU_SLEEP();  /* atomically go to sleep and enable interrupts */
    QF_INT_ENABLE(); /* for now, just enable interrupts */
#else
    QF_INT_ENABLE(); /* just enable interrupts */
#endif
}

/*..........................................................................*/
void Q_onAssert(char const *module, int loc) {
    /*
    * NOTE: add here your application-specific error handling
    */
    (void)module;
    (void)loc;
    QS_ASSERTION(module, loc, (uint32_t)10000U); /* report assertion to QS */
    NVIC_SystemReset();
}

/* QS callbacks ============================================================*/
#ifdef Q_SPY
/*..........................................................................*/
#define __DIV(__PCLK, __BAUD)       (((__PCLK / 4) *25)/(__BAUD))
#define __DIVMANT(__PCLK, __BAUD)   (__DIV(__PCLK, __BAUD)/100)
#define __DIVFRAQ(__PCLK, __BAUD)   \
    (((__DIV(__PCLK, __BAUD) - (__DIVMANT(__PCLK, __BAUD) * 100)) \
        * 16 + 50) / 100)
#define __USART_BRR(__PCLK, __BAUD) \
    ((__DIVMANT(__PCLK, __BAUD) << 4)|(__DIVFRAQ(__PCLK, __BAUD) & 0x0F))

/*..........................................................................*/
uint8_t QS_onStartup(void const *arg) {
    static uint8_t qsBuf[2*1024]; /* buffer for Quantum Spy */

    (void)arg; /* avoid the "unused parameter" compiler warning */
    QS_initBuf(qsBuf, sizeof(qsBuf));

    /* enable peripheral clock for USART2 */
    RCC->AHBENR   |=  (1U <<  0);   /* Enable GPIOA clock   */
    RCC->APB1ENR  |=  (1U << 17);   /* Enable USART#2 clock */

    /* Configure PA3 to USART2_RX, PA2 to USART2_TX */
    GPIOA->AFR[0] &= ~((15U << 4*3) | (15U << 4*2));
    GPIOA->AFR[0] |=  (( 7U << 4*3) | ( 7U << 4*2));
    GPIOA->MODER  &= ~(( 3U << 2*3) | ( 3U << 2*2));
    GPIOA->MODER  |=  (( 2U << 2*3) | ( 2U << 2*2));

    USART2->BRR  = __USART_BRR(SystemCoreClock, 115200U);  /* baud rate */
    USART2->CR3  = 0x0000U;        /* no flow control          */
    USART2->CR2  = 0x0000U;        /* 1 stop bit               */
    USART2->CR1  = ((1U <<  2) |   /* enable RX                */
                    (1U <<  3) |   /* enable TX                */
                    (0U << 12) |   /* 1 start bit, 8 data bits */
                    (1U << 13));   /* enable USART             */


    /* setup the QS filters... */
    QS_FILTER_ON(QS_QEP_STATE_ENTRY);
    QS_FILTER_ON(QS_QEP_STATE_EXIT);
    QS_FILTER_ON(QS_QEP_STATE_INIT);
    QS_FILTER_ON(QS_QEP_INIT_TRAN);
    QS_FILTER_ON(QS_QEP_INTERN_TRAN);
    QS_FILTER_ON(QS_QEP_TRAN);
    QS_FILTER_ON(QS_QEP_IGNORED);
    QS_FILTER_ON(QS_QEP_DISPATCH);
    QS_FILTER_ON(QS_QEP_UNHANDLED);

    QS_FILTER_ON(PHILO_STAT);

    return (uint8_t)1; /* return success */
}
/*..........................................................................*/
void QS_onCleanup(void) {
}
/*..........................................................................*/
QSTimeCtr QS_onGetTime(void) { /* NOTE: invoked with interrupts DISABLED */
    if ((SysTick->CTRL & 0x00010000) == 0) {  /* COUNT no set? */
        return QS_tickTime_ - (QSTimeCtr)SysTick->VAL;
    }
    else { /* the rollover occured, but the SysTick_ISR did not run yet */
        return QS_tickTime_ + QS_tickPeriod_ - (QSTimeCtr)SysTick->VAL;
    }
}
/*..........................................................................*/
void QS_onFlush(void) {
    uint16_t b;

    QF_INT_DISABLE();
    while ((b = QS_getByte()) != QS_EOD) {    /* while not End-Of-Data... */
        QF_INT_ENABLE();
        while ((USART2->SR & 0x0080U) == 0U) { /* while TXE not empty */
        }
        USART2->DR  = (b & 0xFFU);  /* put into the DR register */
        QF_INT_DISABLE();
    }
    QF_INT_ENABLE();
}
#endif /* Q_SPY */
/*--------------------------------------------------------------------------*/

/*****************************************************************************
* NOTE00:
* The QF_AWARE_ISR_CMSIS_PRI constant from the QF port specifies the highest
* ISR priority that is disabled by the QF framework. The value is suitable
* for the NVIC_SetPriority() CMSIS function.
*
* Only ISRs prioritized at or below the QF_AWARE_ISR_CMSIS_PRI level (i.e.,
* with the numerical values of priorities equal or higher than
* QF_AWARE_ISR_CMSIS_PRI) are allowed to call any QF services. These ISRs
* are "QF-aware".
*
* Conversely, any ISRs prioritized above the QF_AWARE_ISR_CMSIS_PRI priority
* level (i.e., with the numerical values of priorities less than
* QF_AWARE_ISR_CMSIS_PRI) are never disabled and are not aware of the kernel.
* Such "QF-unaware" ISRs cannot call any QF services. The only mechanism
* by which a "QF-unaware" ISR can communicate with the QF framework is by
* triggering a "QF-aware" ISR, which can post/publish events.
*
* NOTE01:
* The QV_onIdle() callback is called with interrupts disabled, because the
* determination of the idle condition might change by any interrupt posting
* an event. QV_onIdle() must internally enable interrupts, ideally
* atomically with putting the CPU to the power-saving mode.
*
* NOTE02:
* The User LED is used to visualize the idle loop activity. The brightness
* The User LED is used to visualize the idle loop activity. The brightness
* of the LED is proportional to the frequency of invcations of the idle loop.
* Please note that the LED is toggled with interrupts locked, so no interrupt
* execution time contributes to the brightness of the User LED.
*/