////////////////////////////////////////////////////////////////////////////////
/*! @file ClocksSimple.c   Convinience functions for AT90USB162 timers/counters.
- Part of the MSDN firmware.
- Part of the Research Assistant project.
- Copyright(C) 2014, Dmitry K. Nelson, St.Petersburg, Russia.
                     D.Nelson@mail.ioffe.ru
- Copyright(C) 2016, Viktor E. Bursian, St.Petersburg, Russia.
                     Viktor.Bursian@mail.ioffe.ru
*///////////////////////////////////////////////////////////////////////////////
#include <ClocksSimple.h>
#include <avr/io.h>
#include <avr/iousb162.h>
//------------------------------------------------------------------------------

#ifndef F_TIMER0
#  ifndef F_CPU
#    error "Neither F_TIMER0 nor F_CPU are defined for ClocksSimple"
#  else
#    define F_TIMER0 F_CPU
#  endif
#endif

#ifndef F_TIMER1
#  ifndef F_CPU
#    error "Neither F_TIMER1 nor F_CPU are defined for ClocksSimple"
#  else
#    define F_TIMER1 F_CPU
#  endif
#endif


int8_t Clock0_Signalled = 0;
int8_t Clock1_Signalled = 0;

//------------------------------------------------------------------------------

#if MCU == at90usb162
//------------------------------------------------------------------------------


const int8_t Clock_DividerLog [6] =
                      //      Divider  |        if F_CPU = 16 MHz
                      //               |  TickFrequency  |  TickInterval
                      { 32 //     inf  |          0      |  inf (clock stopped)
                      ,  0 //       1  |         16 MHz  |      1/16 us
                      ,  3 //       8  |          2 MHz  |      1/2 us
                      ,  6 //      64  |        250 kHz  |     4 us
                      ,  8 //     256  |      62500  Hz  |    16 us
                      , 10 //    1024  |      15625  Hz  |    64 us
                      };

//------------------------------------------------------------------------------

uint32_t  Clock0_TickFrequency (void)
{
  return ((uint32_t)F_TIMER0) >> Clock_DividerLog[ TCCR0B & 0b00000111 ];
}


uint32_t  Clock0_TickInterval (void) /*ns*/
{
  uint32_t  TickFrequency = Clock0_TickFrequency();
  if( TickFrequency ){
    uint32_t  TickInterval = 0x3B9ACA00; // =10^9
    TickInterval /= TickFrequency;
    return TickInterval;
  }else{
    return 0xFFFFFFFF;
  }
}


void  Clock0_SetTickFrequency (uint32_t  frequency/*Hz*/)
{
  uint32_t   CPUFrequency = F_TIMER0;
  uint8_t    Mode;
  frequency <<= 1;
  for( Mode = 1 ; Mode < 6 ; Mode++ ){
    if( frequency > ( CPUFrequency >> Clock_DividerLog[Mode] ) )
      break;
  }
  if( Mode == 6 )  Mode = 0;
  TCCR0B = (TCCR0B & 0b11111000) | Mode;
}


uint32_t  Clock0_Period (void) /*ns*/
{
  return Clock0_TickInterval() * ( (uint16_t)OCR0A + 1 );
}


int8_t  Clock0_SetPeriod (uint32_t  period /*ns*/)
{
  uint32_t  TickFrequency = Clock0_TickFrequency();
  if( TickFrequency ){
    uint32_t  PeriodInTicks = period / Clock0_TickInterval();
    if( PeriodInTicks > 0xFF ){
      OCR0A = 0xFF; //period = 0x100 ticks
      return 1;
    }else if( PeriodInTicks > 1 ){
      OCR0A = (uint8_t)(PeriodInTicks-1);
      return 0;
    }else{
      OCR0A = 0x00; //period = 1 tick
      return -1;
    }
  }
  return -2;
}

//------------------------------------------------------------------------------

uint32_t  Clock1_TickFrequency (void)
{
  return ((uint32_t)F_TIMER1) >> Clock_DividerLog[ TCCR1B & 0b00000111 ];
}


uint32_t  Clock1_TickInterval (void) /*ns*/
{
  uint32_t  TickFrequency = Clock1_TickFrequency();
  if( TickFrequency ){
    uint32_t  TickInterval = 0x3B9ACA00; // =10^9
    TickInterval /= TickFrequency;
    return TickInterval;
  }else{
    return 0xFFFFFFFF;
  }
}


void  Clock1_SetTickFrequency (uint32_t  frequency/*Hz*/)
{
  uint32_t   CPUFrequency = F_TIMER1;
  uint8_t    Mode;
  frequency <<= 1;
  for( Mode = 1 ; Mode < 6 ; Mode++ ){
    if( frequency > ( CPUFrequency >> Clock_DividerLog[Mode] ) )
      break;
  }
  if( Mode == 6 )  Mode = 0;
  TCCR1B = (TCCR1B & 0b11111000) | Mode;
}


uint32_t  Clock1_Period (void) /*ns*/
{
  return Clock1_TickInterval()
       * ( (uint32_t)((((uint16_t)OCR1AH) << 8) + OCR1AL) + 1 );
}


int8_t  Clock1_SetPeriod (uint32_t  period /*ns*/)
{
  uint32_t  TickFrequency = Clock1_TickFrequency();
  if( TickFrequency ){
    uint32_t  PeriodInTicks = period / Clock1_TickInterval();
    if( PeriodInTicks > 0xFFFF ){
      OCR1AH = 0xFF;
      OCR1AL = 0xFF;
      return 1;
    }else if( PeriodInTicks > 1 ){
      OCR1AH = (uint8_t)(((PeriodInTicks-1) >> 8) & 0xFF);
      OCR1AL = (uint8_t)((PeriodInTicks-1) & 0xFF);
      return 0;
    }else{
      OCR1AH = 0x00;
      OCR1AL = 0x00;
      return -1;
    }
  }
  return -2;
}

//------------------------------------------------------------------------------
#endif // MCU == at90usb162