text: /**
   * Marlin 3D Printer Firmware
   * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
   *
   * Based on Sprinter and grbl.
   * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
   *
   * This program is free 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.
   *
   * 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/>.
   *
   */
  #pragma once
  
  /**
   * Description: HAL for
   * Teensy3.2 (__MK20DX256__)
   */
  
  #pragma once
  
  #include <stdint.h>
  
  // ------------------------
  // Defines
  // ------------------------
  
  #define FORCE_INLINE __attribute__((always_inline)) inline
  
  typedef uint32_t hal_timer_t;
  #define HAL_TIMER_TYPE_MAX 0xFFFFFFFF
  
  #define FTM0_TIMER_PRESCALE 8
  #define FTM1_TIMER_PRESCALE 4
  #define FTM0_TIMER_PRESCALE_BITS 0b011
  #define FTM1_TIMER_PRESCALE_BITS 0b010
  
  #define FTM0_TIMER_RATE (F_BUS / (FTM0_TIMER_PRESCALE)) // 60MHz / 8 = 7500kHz
  #define FTM1_TIMER_RATE (F_BUS / (FTM1_TIMER_PRESCALE)) // 60MHz / 4 = 15MHz
  
  #define HAL_TIMER_RATE         (FTM0_TIMER_RATE)
  
  #define STEP_TIMER_NUM 0
  #define TEMP_TIMER_NUM 1
  #define PULSE_TIMER_NUM STEP_TIMER_NUM
  
  #define TEMP_TIMER_FREQUENCY    1000
  
  #define STEPPER_TIMER_RATE     HAL_TIMER_RATE
  #define STEPPER_TIMER_TICKS_PER_US ((STEPPER_TIMER_RATE) / 1000000)
  #define STEPPER_TIMER_PRESCALE (CYCLES_PER_MICROSECOND / STEPPER_TIMER_TICKS_PER_US)
  
  #define PULSE_TIMER_RATE       STEPPER_TIMER_RATE   // frequency of pulse timer
  #define PULSE_TIMER_PRESCALE   STEPPER_TIMER_PRESCALE
  #define PULSE_TIMER_TICKS_PER_US STEPPER_TIMER_TICKS_PER_US
  
  #define ENABLE_STEPPER_DRIVER_INTERRUPT() HAL_timer_enable_interrupt(STEP_TIMER_NUM)
  #define DISABLE_STEPPER_DRIVER_INTERRUPT() HAL_timer_disable_interrupt(STEP_TIMER_NUM)
  #define STEPPER_ISR_ENABLED() HAL_timer_interrupt_enabled(STEP_TIMER_NUM)
  
  #define ENABLE_TEMPERATURE_INTERRUPT() HAL_timer_enable_interrupt(TEMP_TIMER_NUM)
  #define DISABLE_TEMPERATURE_INTERRUPT() HAL_timer_disable_interrupt(TEMP_TIMER_NUM)
  
  #define HAL_STEP_TIMER_ISR()  extern "C" void ftm0_isr(void) //void TC3_Handler()
  #define HAL_TEMP_TIMER_ISR()  extern "C" void ftm1_isr(void) //void TC4_Handler()
  
  void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
  
  FORCE_INLINE static void HAL_timer_set_compare(const uint8_t timer_num, const hal_timer_t compare) {
    switch (timer_num) {
      case 0: FTM0_C0V = compare; break;
      case 1: FTM1_C0V = compare; break;
    }
  }
  
  FORCE_INLINE static hal_timer_t HAL_timer_get_compare(const uint8_t timer_num) {
    switch (timer_num) {
      case 0: return FTM0_C0V;
      case 1: return FTM1_C0V;
    }
    return 0;
  }
  
  FORCE_INLINE static hal_timer_t HAL_timer_get_count(const uint8_t timer_num) {
    switch (timer_num) {
      case 0: return FTM0_CNT;
      case 1: return FTM1_CNT;
    }
    return 0;
  }
  
  void HAL_timer_enable_interrupt(const uint8_t timer_num);
  void HAL_timer_disable_interrupt(const uint8_t timer_num);
  bool HAL_timer_interrupt_enabled(const uint8_t timer_num);
  
  void HAL_timer_isr_prologue(const uint8_t timer_num);
  #define HAL_timer_isr_epilogue(TIMER_NUM)
  