/**************************************************************************//**
 * @file     etimer.c
 * @brief    ETIMER driver source file
 *
 * SPDX-License-Identifier: Apache-2.0
 * @copyright (C) 2018 Nuvoton Technology Corp. All rights reserved.
*****************************************************************************/
#include "nuc980.h"
#include "nu_sys.h"

/// @cond HIDDEN_SYMBOLS

/**
  * @brief This API is used to get the clock frequency of Timer
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @return Timer clock frequency
  * @note This API cannot return correct clock rate if timer source is external clock input.
  */
UINT ETIMER_GetModuleClock(UINT timer)
{
    UINT src;

    src = (inpw(REG_CLK_DIVCTL8) >> (16 + timer * 2)) & 0x3;

    if (src == 0)
        return 12000000;
    else if (src == 1)
        return (sysGetClock(SYS_PCLK01) * 1000000);
    else if (src == 2)
        return (sysGetClock(SYS_PCLK01) * 1000000 / 4096);
    else
        return 32768;

}

/// @endcond /* HIDDEN_SYMBOLS */

/** @addtogroup Standard_Driver Standard Driver
  @{
*/

/** @addtogroup ETIMER_Driver ETIMER Driver
  @{
*/


/** @addtogroup ETIMER_EXPORTED_FUNCTIONS ETIMER Exported Functions
  @{
*/

/**
  * @brief This API is used to configure timer to operate in specified mode
  *        and frequency. If timer cannot work in target frequency, a closest
  *        frequency will be chose and returned.
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @param[in] u32Mode Operation mode. Possible options are
  *                 - \ref ETIMER_ONESHOT_MODE
  *                 - \ref ETIMER_PERIODIC_MODE
  *                 - \ref ETIMER_TOGGLE_MODE
  *                 - \ref ETIMER_CONTINUOUS_MODE
  * @param[in] u32Freq Target working frequency
  * @return Real Timer working frequency
  * @note After calling this API, Timer is \b NOT running yet. But could start timer running be calling
  *       \ref ETIMER_Start macro or program registers directly
  */
UINT ETIMER_Open(UINT timer, UINT u32Mode, UINT u32Freq)
{
    UINT u32Clk = ETIMER_GetModuleClock(timer);
    UINT u32Cmpr = 0, u32Prescale = 0;

    // Fastest possible timer working freq is u32Clk / 2. While cmpr = 2, pre-scale = 0
    if (u32Freq > (u32Clk / 2))
    {
        u32Cmpr = 2;
    }
    else
    {
        if (u32Clk >= 0x8000000)
        {
            u32Prescale = 15;    // real prescaler value is 16
            u32Clk >>= 4;
        }
        else if (u32Clk >= 0x4000000)
        {
            u32Prescale = 7;    // real prescaler value is 8
            u32Clk >>= 3;
        }
        else if (u32Clk >= 0x2000000)
        {
            u32Prescale = 3;    // real prescaler value is 4
            u32Clk >>= 2;
        }
        else if (u32Clk >= 0x1000000)
        {
            u32Prescale = 1;    // real prescaler value is 2
            u32Clk >>= 1;
        }
        u32Cmpr = u32Clk / u32Freq;
    }

    if (timer == 0)
    {
        outpw(REG_ETMR0_CMPR, u32Cmpr);
        outpw(REG_ETMR0_PRECNT, u32Prescale);
        outpw(REG_ETMR0_CTL, 1 | u32Mode);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CMPR, u32Cmpr);
        outpw(REG_ETMR1_PRECNT, u32Prescale);
        outpw(REG_ETMR1_CTL, 1 | u32Mode);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CMPR, u32Cmpr);
        outpw(REG_ETMR2_PRECNT, u32Prescale);
        outpw(REG_ETMR2_CTL, 1 | u32Mode);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CMPR, u32Cmpr);
        outpw(REG_ETMR3_PRECNT, u32Prescale);
        outpw(REG_ETMR3_CTL, 1 | u32Mode);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CMPR, u32Cmpr);
        outpw(REG_ETMR4_PRECNT, u32Prescale);
        outpw(REG_ETMR4_CTL, 1 | u32Mode);
    }
    else
    {
        outpw(REG_ETMR5_CMPR, u32Cmpr);
        outpw(REG_ETMR5_PRECNT, u32Prescale);
        outpw(REG_ETMR5_CTL, 1 | u32Mode);
    }

    return (u32Clk / (u32Cmpr * (u32Prescale + 1)));
}

/**
  * @brief This API stops Timer counting and disable the Timer interrupt function
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @return None
  */
void ETIMER_Close(UINT timer)
{
    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, 0);
        outpw(REG_ETMR0_IER, 0);
        outpw(REG_ETMR0_DR, 0);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, 0);
        outpw(REG_ETMR1_IER, 0);
        outpw(REG_ETMR1_DR, 0);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, 0);
        outpw(REG_ETMR2_IER, 0);
        outpw(REG_ETMR2_DR, 0);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, 0);
        outpw(REG_ETMR3_IER, 0);
        outpw(REG_ETMR3_DR, 0);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, 0);
        outpw(REG_ETMR4_IER, 0);
        outpw(REG_ETMR4_DR, 0);
    }
    else
    {
        outpw(REG_ETMR5_CTL, 0);
        outpw(REG_ETMR5_IER, 0);
        outpw(REG_ETMR5_DR, 0);
    }
}

/**
  * @brief This API is used to create a delay loop for u32usec micro seconds
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @param[in] u32Usec Delay period in micro seconds with 10 usec every step. Valid values are between 10~1000000 (10 micro second ~ 1 second)
  * @return None
  * @note This API overwrites the register setting of the timer used to count the delay time.
  * @note This API use polling mode. So there is no need to enable interrupt for the timer module used to generate delay
  */
void ETIMER_Delay(UINT timer, UINT u32Usec)
{
    UINT u32Clk = ETIMER_GetModuleClock(timer);
    UINT u32Prescale = 0, delay = 300000000 / u32Clk;
    float fCmpr;

    // Clear current timer configuration
    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, 0);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, 0);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, 0);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, 0);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, 0);
    }
    else
    {
        outpw(REG_ETMR5_CTL, 0);
    }

    if (u32Clk == 10000)          // min delay is 100us if timer clock source is LIRC 10k
    {
        u32Usec = ((u32Usec + 99) / 100) * 100;
    }
    else        // 10 usec every step
    {
        u32Usec = ((u32Usec + 9) / 10) * 10;
    }

    if (u32Clk >= 0x4000000)
    {
        u32Prescale = 7;    // real prescaler value is 8
        u32Clk >>= 3;
    }
    else if (u32Clk >= 0x2000000)
    {
        u32Prescale = 3;    // real prescaler value is 4
        u32Clk >>= 2;
    }
    else if (u32Clk >= 0x1000000)
    {
        u32Prescale = 1;    // real prescaler value is 2
        u32Clk >>= 1;
    }

    // u32Usec * u32Clk might overflow if using UINT
    fCmpr = ((float)u32Usec * (float)u32Clk) / 1000000.0;

    if (timer == 0)
    {
        outpw(REG_ETMR0_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR0_PRECNT, u32Prescale);
        outpw(REG_ETMR0_CTL, 1);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR1_PRECNT, u32Prescale);
        outpw(REG_ETMR1_CTL, 1);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR2_PRECNT, u32Prescale);
        outpw(REG_ETMR2_CTL, 1);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR3_PRECNT, u32Prescale);
        outpw(REG_ETMR3_CTL, 1);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR4_PRECNT, u32Prescale);
        outpw(REG_ETMR4_CTL, 1);
    }
    else
    {
        outpw(REG_ETMR5_CMPR, (UINT)fCmpr);
        outpw(REG_ETMR5_PRECNT, u32Prescale);
        outpw(REG_ETMR5_CTL, 1);
    }

    // When system clock is faster than timer clock, it is possible timer active bit cannot set in time while we check it.
    // And the while loop below return immediately, so put a tiny delay here allowing timer start counting and raise active flag.
    for (; delay > 0; delay--)
    {
#if defined (__GNUC__) && !(__CC_ARM)
        __asm__ __volatile__
        (
            "nop  \n"
        );
#else
        __asm
        {
            NOP
        }
#endif
    }

    if (timer == 0)
    {
        while (inpw(REG_ETMR0_CTL) & 0x80);
    }
    else if (timer == 1)
    {
        while (inpw(REG_ETMR1_CTL) & 0x80);
    }
    else if (timer == 2)
    {
        while (inpw(REG_ETMR2_CTL) & 0x80);
    }
    else if (timer == 3)
    {
        while (inpw(REG_ETMR3_CTL) & 0x80);
    }
    else if (timer == 4)
    {
        while (inpw(REG_ETMR4_CTL) & 0x80);
    }
    else
    {
        while (inpw(REG_ETMR5_CTL) & 0x80);
    }
}

/**
  * @brief This API is used to enable timer capture function with specified mode and capture edge
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @param[in] u32CapMode Timer capture mode. Could be
  *                 - \ref ETIMER_CAPTURE_FREE_COUNTING_MODE
  *                 - \ref ETIMER_CAPTURE_TRIGGER_COUNTING_MODE
  *                 - \ref ETIMER_CAPTURE_COUNTER_RESET_MODE
  * @param[in] u32Edge Timer capture edge. Possible values are
  *                 - \ref ETIMER_CAPTURE_FALLING_EDGE
  *                 - \ref ETIMER_CAPTURE_RISING_EDGE
  *                 - \ref ETIMER_CAPTURE_FALLING_THEN_RISING_EDGE
  *                 - \ref ETIMER_CAPTURE_RISING_THEN_FALLING_EDGE
  * @return None
  * @note Timer frequency should be configured separately by using \ref ETIMER_Open API, or program registers directly
  */
void ETIMER_EnableCapture(UINT timer, UINT u32CapMode, UINT u32Edge)
{
    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, (inpw(REG_ETMR0_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, (inpw(REG_ETMR1_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, (inpw(REG_ETMR2_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, (inpw(REG_ETMR3_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, (inpw(REG_ETMR4_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
    else
    {
        outpw(REG_ETMR5_CTL, (inpw(REG_ETMR5_CTL) & ~0x1E0000) | u32CapMode | u32Edge | 0x10000);
    }
}

/**
  * @brief This API is used to disable the Timer capture function
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @return None
  */
void ETIMER_DisableCapture(UINT timer)
{
    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, inpw(REG_ETMR0_CTL) & ~0x10000);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, inpw(REG_ETMR1_CTL) & ~0x10000);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, inpw(REG_ETMR2_CTL) & ~0x10000);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, inpw(REG_ETMR3_CTL) & ~0x10000);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, inpw(REG_ETMR4_CTL) & ~0x10000);
    }
    else
    {
        outpw(REG_ETMR5_CTL, inpw(REG_ETMR5_CTL) & ~0x10000);
    }

}

/**
  * @brief This function is used to enable the Timer counter function with specify detection edge
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @param[in] u32Edge Detection edge of counter pin. Could be ether
  *             - \ref TIMER_COUNTER_RISING_EDGE, or
  *             - \ref TIMER_COUNTER_FALLING_EDGE
  * @return None
  * @note Timer compare value should be configured separately by using \ref ETIMER_SET_CMP_VALUE macro or program registers directly
  */
void ETIMER_EnableEventCounter(UINT timer, uint32_t u32Edge)
{

    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, (inpw(REG_ETMR0_CTL) & ~0x2000) | u32Edge | 0x1000);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, (inpw(REG_ETMR1_CTL) & ~0x2000) | u32Edge | 0x1000);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, (inpw(REG_ETMR2_CTL) & ~0x2000) | u32Edge | 0x1000);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, (inpw(REG_ETMR3_CTL) & ~0x2000) | u32Edge | 0x1000);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, (inpw(REG_ETMR4_CTL) & ~0x2000) | u32Edge | 0x1000);
    }
    else
    {
        outpw(REG_ETMR5_CTL, (inpw(REG_ETMR5_CTL) & ~0x2000) | u32Edge | 0x1000);
    }

}

/**
  * @brief This API is used to disable the Timer event counter function.
  * @param[in] timer ETIMER number. Range from 0 ~ 5
  * @return None
  */
void ETIMER_DisableEventCounter(UINT timer)
{
    if (timer == 0)
    {
        outpw(REG_ETMR0_CTL, inpw(REG_ETMR0_CTL) & ~0x1000);
    }
    else if (timer == 1)
    {
        outpw(REG_ETMR1_CTL, inpw(REG_ETMR1_CTL) & ~0x1000);
    }
    else if (timer == 2)
    {
        outpw(REG_ETMR2_CTL, inpw(REG_ETMR2_CTL) & ~0x1000);
    }
    else if (timer == 3)
    {
        outpw(REG_ETMR3_CTL, inpw(REG_ETMR3_CTL) & ~0x1000);
    }
    else if (timer == 4)
    {
        outpw(REG_ETMR4_CTL, inpw(REG_ETMR4_CTL) & ~0x1000);
    }
    else
    {
        outpw(REG_ETMR5_CTL, inpw(REG_ETMR5_CTL) & ~0x1000);
    }
}


/*@}*/ /* end of group ETIMER_EXPORTED_FUNCTIONS */

/*@}*/ /* end of group ETIMER_Driver */

/*@}*/ /* end of group Standard_Driver */

/*** (C) COPYRIGHT 2018 Nuvoton Technology Corp. ***/