/************************************************************************/
/*                                                                      */
/*  File:           avr/pwm.c                                           */
/*  Description:    pulse width modulation driver.                      */
/*  Version:        1.0                                                 */
/*  Author:         Otto Mattik                                         */
/*                                                                      */
/*  (C)Copyright Otto Mattik 2014-2021.                                 */
/*                                                                      */
/*  This file is a part of 'armen' (a tiny operating system).           */
/*  'armen' is distributed under the CeCILL-V2.1 licence. For more      */
/*  details about this licence, please visit the website cecill.info    */
/*                                                                      */
/************************************************************************/

#ifndef AVR_GPIO_C
  #error "do not use this code directly, it must be included via gpio.c"
#endif

#if defined(__AVR_ATtiny84__)\
 || defined(__AVR_ATtiny85__)
  #if defined(UART) && (UART != 0)
    #error "pwm and uart, used together, are incompatible"
  #endif
#endif

#if defined(__AVR_ATtiny84__)
  #define GPIO_MAX_PWM      1
#elif defined(__AVR_ATtiny841__)
  #define GPIO_MAX_PWM      2
#elif defined(__AVR_ATtiny85__)
  #define GPIO_MAX_PWM      1
#elif defined(__AVR_ATtiny1634__)
  #define GPIO_MAX_PWM      1
#elif defined(__AVR_ATmega328P__)
  #define GPIO_MAX_PWM      2
#elif defined(__AVR_ATmega2560__)
  #define GPIO_MAX_PWM      5
#endif

/*
  __AVR_ATtiny84__
  t1, 16 bits, OC1A=PA6/6, OC1B=PA5/5
  __AVR_ATtiny85__
  t1,  8 bits, OC1A=PB1/1, OC1B=PB4/4
  __AVR_ATtiny841__
  t1, 16 bits, OC1A=TOCC1|TOCC3|TOCC5|TOCC7, OC1B=TOCC0|TOCC2|TOCC4|TOCC6
  t2, 16 bits, OC2A=TOCC1|TOCC3|TOCC5|TOCC7, OC2B=TOCC0|TOCC2|TOCC4|TOCC6
  __AVR_ATtiny1634__
  t1, 16 bits, OC1A=PC0/16, OC1B=PB3/11
  __AVR_ATmega328P__
  t1, 16 bits, OC1A=PB1/1, OC1B=PB2/2
  t2,  8 bits, OC2A=PB3/3, OC2B=PD3/19
  __AVR_ATmega2560__
  t1, 16 bits, OC1A=PB5/13, OC1B=PB6/14, 0C1C=PB7/15
  t2,  8 bits, OC2A=PB4/12, OC2B=PH6/62
  t3, 16 bits, OC3A=PE3/35, OC3B=PE4/36, OC3C=PE5/37
  t4, 16 bits, OC4A=PH3/59, OC4B=PH4/60, OC4C=PH5/61
  t5, 16 bits, OC5A=PL3/83, OC5B=PL4/84, OC5C=PL5/85
*/
static uint8_t pwm_freq = 0;

static struct {
    uint8_t* tccra;
    uint8_t* tccrb;
    uint8_t* ocra;
    uint8_t* ocrb;
    uint8_t* ocrc;
    uint8_t  modea;
    uint8_t  modeb;
    uint8_t  bytes;
} pwms[GPIO_MAX_PWM] = {
#if defined(__AVR_ATtiny84__)
    { 0x004F, 0x004E, 0x004A, 0x0048, 0x0000,
      (1<<COM1A1)|(1<<COM1B1)|(1<<WGM10), (1<<WGM12), 2 }
#elif defined(__AVR_ATtiny85__)
    { 0x002A, 0x0033, 0x0029, 0x0028, 0x0000,
      (1<<COM0A1)(1<<COM0B1)|(1<<WGM01)|(1<<WGM00), 0, 1 }
#elif defined(__AVR_ATtiny841__)
    { 0x004F, 0x004E, 0x004A, 0x0048, 0x0000,
      (1<<COM1A1)|(1<<COM1B1)|(1<<WGM10), (1<<WGM12), 2 },
  #if 0
    { 0x00CA, 0x00C9, 0x00C4, 0x00C2, 0x0000,
      (1<<COM2A1)|(1<<COM2B1)|(1<<WGM20), (1<<WGM22), 2 }
  #endif
#elif defined(__AVR_ATtiny1634__)
    { 0x0072, 0x0071, 0x006C, 0x006A, 0x0000,
      (1<<COM1A1)|(1<<COM1B1)|(1<<WGM10), (1<<WGM12), 2 }
#elif defined(__AVR_ATmega328P__)
    { 0x0080, 0x0081, 0x0088, 0x008A, 0x0000,
      (1<<COM1A1)|(1<<COM1B1)|(1<<WGM10), (1<<WGM12), 2 },
    { 0x00B0, 0x00B1, 0x00B3, 0x00B4, 0x0000,
      (1<<COM2A1)|(1<<COM2B1)|(1<<WGM21)|(1<<WGM20), 0, 1 }
#elif defined(__AVR_ATmega2560__)
    { 0x0080, 0x0081, 0x0088, 0x008A, 0x008C,
      (1<<COM1A1)|(1<<COM1B1)|(1<<COM1C1)|(1<<WGM10), (1<<WGM12), 2 },
    { 0x00B0, 0x00B1, 0x00B3, 0x00B4, 0x0000,
      (1<<COM2A1)|(1<<COM2B1)|(1<<WGM21)|(1<<WGM20), 0, 1 },
    { 0x0090, 0x0091, 0x0098, 0x009A, 0x009C,
      (1<<COM3A1)|(1<<COM3B1)|(1<<COM3C1)|(1<<WGM30), (1<<WGM32), 2 },
    { 0x00A0, 0x00A1, 0x00A8, 0x00AB, 0x00AC,
      (1<<COM4A1)|(1<<COM4B1)|(1<<COM4C1)|(1<<WGM40), (1<<WGM42), 2 },
    { 0x0120, 0x0121, 0x0128, 0x012A, 0x012C,
      (1<<COM5A1)|(1<<COM5B1)|(1<<COM5C1)|(1<<WGM50), (1<<WGM52), 2 }
#endif
};

void gpio_pwm_freq( uint8_t scale )
{
#ifdef CHECK_PARAM
    if( scale >= 1 && scale <= 5 )
#endif
    {
        uint8_t i;

        /* set fast pwm (8 bits) mode with OCnA and 0CnB cleared on compare match */
        for( i = 0; i < GPIO_MAX_PWM; i++ )
        {
            *pwms[i].tccra = pwms[i].modea;
#if defined(__AVR_ATmega328P__)\
 || defined(__AVR_ATmega2560__)
            if( i == 1 && scale > 2 )
            {
                uint8_t value;
                if( scale == 3 )
                    value = 4;
                else if( scale == 4 )
                    value = 6;
                else
                    value = 7;
                *pwms[i].tccrb = pwms[i].modeb | value;
            else
#endif
            *pwms[i].tccrb = pwms[i].modeb | scale;
            *pwms[i].ocra = 0;
            *pwms[i].ocrb = 0;
            if( pwms[i].ocrc != 0 )
                *pwms[i].ocrc = 0;
        }
    }
}

void gpio_pwm_set( uint8_t gpio, uint8_t percent )
{
#ifdef CHECK_PARAM
    if( gpio < (GPIO_MAX_PORT << 3) )
#endif
    {
        uint8_t timer = 0;

#if defined(__AVR_ATtiny84__)
        if( gpio == 6 || gpio == 5 )
        {
            gpio = 6 - gpio;
#elif defined(__AVR_ATtiny85__)
        if( gpio == 1 || gpio == 4 )
        {
            gpio = (gpio == 1 ? 0 : 1);
#elif defined(__AVR_ATtiny841__)
        if( gpio <= 7 )
        {
            /* OC1A=TOCC1|TOCC3|TOCC5|TOCC7
               OC1B=TOCC0|TOCC2|TOCC4|TOCC6 */
            if( gpio <= 3 )
                TOCPMSA0 |= (01 << (gpio << 2));
            else
                TOCPMSA1 |= (01 << ((gpio - 4) << 2));
            TOCPMCOE |= (1 << gpio);
            gpio = ((gpio & 1) == 1 ? 0 : 1);
#elif defined(__AVR_ATtiny1634__)
        if( gpio == 16 || gpio == 11 )
        {
            gpio = (gpio == 16 ? 0 : 1);
#elif defined(__AVR_ATmega328P__)
        if( gpio == 1 || gpio == 2 )
            gpio -= 1;
        else if( gpio == 3 || gpio == 19 )
        {
            gpio = (gpio == 3 ? 0 : 1);
            timer = 1;
        }
        else
            return;
        {
#elif defined(__AVR_ATmega2560__)
        if( gpio >= 13 || gpio <= 15 )
            gpio -= 13;
        else if( gpio == 12 || gpio == 62 )
        {
            gpio = (gpio == 12 ? 0 : 1);
            timer = 1;
        }
        else if( gpio >= 35 && gpio <= 37 )
        {
            gpio -= 35;
            timer = 2;
        }
        else if( gpio >= 59 && gpio <= 61 )
        {
            gpio -= 59;
            timer = 3;
        }
        else if( gpio >= 83 && gpio <= 85 )
        {
            gpio -= 83;
            timer = 4;
        }
        else
            return;
        {
#endif
            percent = (255 * percent) / 100;
            if( gpio == 0 )
                *pwms[timer].ocra = percent;
#if defined(__AVR_ATmega2560__)
            else if( gpio == 2 )
                *pwms[timer].ocrc = percent;
#endif
            else
                *pwms[timer].ocrb = percent;
        }
    }
}