Marlin_Firmware/Marlin/src/HAL/HAL_TEENSY31_32/HAL_SPI.cpp

/**
 * 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/>.
 *
 */
#ifdef __MK20DX256__

#include "HAL.h"
#include <SPI.h>
#include <pins_arduino.h>
#include "spi_pins.h"
#include "../../core/macros.h"

static SPISettings spiConfig;

/**
 * Standard SPI functions
 */

// Initialize SPI bus
void spiBegin() {
  #if !PIN_EXISTS(SS)
    #error "SS_PIN not defined!"
  #endif
  OUT_WRITE(SS_PIN, HIGH);
  SET_OUTPUT(SCK_PIN);
  SET_INPUT(MISO_PIN);
  SET_OUTPUT(MOSI_PIN);

  #if 0 && DISABLED(SOFTWARE_SPI)
    // set SS high - may be chip select for another SPI device
    #if SET_SPI_SS_HIGH
      WRITE(SS_PIN, HIGH);
    #endif
    // set a default rate
    spiInit(SPI_HALF_SPEED); // 1
  #endif
}

// Configure SPI for specified SPI speed
void spiInit(uint8_t spiRate) {
  // Use data rates Marlin uses
  uint32_t clock;
  switch (spiRate) {
    case SPI_FULL_SPEED:    clock = 10000000; break;
    case SPI_HALF_SPEED:    clock =  5000000; break;
    case SPI_QUARTER_SPEED: clock =  2500000; break;
    case SPI_EIGHTH_SPEED:  clock =  1250000; break;
    case SPI_SPEED_5:       clock =   625000; break;
    case SPI_SPEED_6:       clock =   312500; break;
    default:                clock = 4000000; // Default from the SPI libarary
  }
  spiConfig = SPISettings(clock, MSBFIRST, SPI_MODE0);
  SPI.begin();
}

// SPI receive a byte
uint8_t spiRec() {
  SPI.beginTransaction(spiConfig);
  const uint8_t returnByte = SPI.transfer(0xFF);
  SPI.endTransaction();
  return returnByte;
  //SPDR = 0xFF;
  //while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
  //return SPDR;
}

// SPI read data
void spiRead(uint8_t* buf, uint16_t nbyte) {
  SPI.beginTransaction(spiConfig);
  SPI.transfer(buf, nbyte);
  SPI.endTransaction();
  //if (nbyte-- == 0) return;
  //  SPDR = 0xFF;
  //for (uint16_t i = 0; i < nbyte; i++) {
  //  while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
  //  buf[i] = SPDR;
  //  SPDR = 0xFF;
  //}
  //while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ }
  //buf[nbyte] = SPDR;
}

// SPI send a byte
void spiSend(uint8_t b) {
  SPI.beginTransaction(spiConfig);
  SPI.transfer(b);
  SPI.endTransaction();
  //SPDR = b;
  //while (!TEST(SPSR, SPIF)) { /* nada */ }
}

// SPI send block
void spiSendBlock(uint8_t token, const uint8_t* buf) {
  SPI.beginTransaction(spiConfig);
  SPDR = token;
  for (uint16_t i = 0; i < 512; i += 2) {
    while (!TEST(SPSR, SPIF)) { /* nada */ };
    SPDR = buf[i];
    while (!TEST(SPSR, SPIF)) { /* nada */ };
    SPDR = buf[i + 1];
  }
  while (!TEST(SPSR, SPIF)) { /* nada */ };
  SPI.endTransaction();
}


// Begin SPI transaction, set clock, bit order, data mode
void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) {
  spiConfig = SPISettings(spiClock, bitOrder, dataMode);
  SPI.beginTransaction(spiConfig);
}

#endif // __MK20DX256__