Firmware2/Marlin/src/HAL/HAL_DUE/u8g_com_HAL_DUE_st7920_sw_spi.cpp

/**
 * Marlin 3D Printer Firmware
 * Copyright (C) 2016, 2017 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/>.
 *
 */

/*

  based on u8g_com_st7920_hw_spi.c

  Universal 8bit Graphics Library

  Copyright (c) 2011, olikraus@gmail.com
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification,
  are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this list
    of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright notice, this
    list of conditions and the following disclaimer in the documentation and/or other
    materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#ifdef ARDUINO_ARCH_SAM

#include <U8glib.h>
#include <Arduino.h>
#include "../../core/macros.h"

void u8g_SetPIOutput_DUE(u8g_t *u8g, uint8_t pin_index) {
   PIO_Configure(g_APinDescription[u8g->pin_list[pin_index]].pPort, PIO_OUTPUT_1,
     g_APinDescription[u8g->pin_list[pin_index]].ulPin, g_APinDescription[u8g->pin_list[pin_index]].ulPinConfiguration);  // OUTPUT
}

void u8g_SetPILevel_DUE(u8g_t *u8g, uint8_t pin_index, uint8_t level) {
  volatile Pio* port = g_APinDescription[u8g->pin_list[pin_index]].pPort;
  uint32_t mask = g_APinDescription[u8g->pin_list[pin_index]].ulPin;
  if (level) port->PIO_SODR = mask;
  else port->PIO_CODR = mask;
}

#define nop() __asm__ __volatile__("nop;\n\t":::)

void __delay_4cycles(uint32_t cy) __attribute__ ((weak));

FORCE_INLINE void __delay_4cycles(uint32_t cy) { // +1 cycle
  #if ARCH_PIPELINE_RELOAD_CYCLES<2
    #define EXTRA_NOP_CYCLES "nop"
  #else
    #define EXTRA_NOP_CYCLES ""
  #endif

  __asm__ __volatile__(
    ".syntax unified" "\n\t" // is to prevent CM0,CM1 non-unified syntax

    "loop%=:" "\n\t"
    " subs %[cnt],#1" "\n\t"
    EXTRA_NOP_CYCLES "\n\t"
    " bne loop%=" "\n\t"
    : [cnt]"+r"(cy) // output: +r means input+output
    : // input:
    : "cc" // clobbers:
  );
}

Pio *SCK_pPio, *MOSI_pPio;
uint32_t SCK_dwMask, MOSI_dwMask;

static void spiSend_sw_DUE(uint8_t val) { // 800KHz
  for (uint8_t i = 0; i < 8; i++) {
    if (val & 0x80)
      MOSI_pPio->PIO_SODR = MOSI_dwMask;
    else
      MOSI_pPio->PIO_CODR = MOSI_dwMask;
    __delay_4cycles(1);
    SCK_pPio->PIO_SODR = SCK_dwMask;
    __delay_4cycles(19); // 16 dead, 17 garbage, 18/0 900kHz, 19/1 825k, 20/1 800k, 21/2 725KHz
    val <<= 1;
    SCK_pPio->PIO_CODR = SCK_dwMask;
  }
}

static uint8_t rs_last_state = 255;

static void u8g_com_DUE_st7920_write_byte_sw_spi(uint8_t rs, uint8_t val) {
  uint8_t i;

  if ( rs != rs_last_state) {  // time to send a command/data byte
    rs_last_state = rs;

    if ( rs == 0 )
      /* command */
      spiSend_sw_DUE(0x0f8);
    else
       /* data */
      spiSend_sw_DUE(0x0fa);

    for (i = 0; i < 4; i++)   // give the controller some time to process the data
      u8g_10MicroDelay();     // 2 is bad, 3 is OK, 4 is safe
  }

  spiSend_sw_DUE(val & 0x0f0);
  spiSend_sw_DUE(val << 4);
}


uint8_t u8g_com_HAL_DUE_ST7920_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
  switch (msg) {
    case U8G_COM_MSG_INIT:
      SCK_pPio = g_APinDescription[u8g->pin_list[U8G_PI_SCK]].pPort;
      SCK_dwMask = g_APinDescription[u8g->pin_list[U8G_PI_SCK]].ulPin;
      MOSI_pPio = g_APinDescription[u8g->pin_list[U8G_PI_MOSI]].pPort;
      MOSI_dwMask = g_APinDescription[u8g->pin_list[U8G_PI_MOSI]].ulPin;

      u8g_SetPILevel_DUE(u8g, U8G_PI_CS, 0);
      u8g_SetPIOutput_DUE(u8g, U8G_PI_CS);
      u8g_SetPILevel_DUE(u8g, U8G_PI_SCK, 0);
      u8g_SetPIOutput_DUE(u8g, U8G_PI_SCK);
      u8g_SetPILevel_DUE(u8g, U8G_PI_MOSI, 0);
      u8g_SetPIOutput_DUE(u8g, U8G_PI_MOSI);
      
      SCK_pPio->PIO_CODR = SCK_dwMask;   //SCK low - needed at power up but not after reset
      MOSI_pPio->PIO_CODR = MOSI_dwMask; //MOSI low - needed at power up but not after reset
      
      u8g_Delay(5);

      u8g->pin_list[U8G_PI_A0_STATE] = 0;       /* inital RS state: command mode */
      break;

    case U8G_COM_MSG_STOP:
      break;

    case U8G_COM_MSG_RESET:
       if (U8G_PIN_NONE != u8g->pin_list[U8G_PI_RESET]) u8g_SetPILevel_DUE(u8g, U8G_PI_RESET, arg_val);
      break;

    case U8G_COM_MSG_ADDRESS:                     /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
      u8g->pin_list[U8G_PI_A0_STATE] = arg_val;
      break;

    case U8G_COM_MSG_CHIP_SELECT:
      if (U8G_PIN_NONE != u8g->pin_list[U8G_PI_CS])
        u8g_SetPILevel_DUE(u8g, U8G_PI_CS, arg_val);  //note: the st7920 has an active high chip select
      break;

    case U8G_COM_MSG_WRITE_BYTE:

      u8g_com_DUE_st7920_write_byte_sw_spi(u8g->pin_list[U8G_PI_A0_STATE], arg_val);
      break;

    case U8G_COM_MSG_WRITE_SEQ: {
        uint8_t *ptr = (uint8_t*) arg_ptr;
        while (arg_val > 0) {
          u8g_com_DUE_st7920_write_byte_sw_spi(u8g->pin_list[U8G_PI_A0_STATE], *ptr++);
          arg_val--;
        }
      }
      break;

      case U8G_COM_MSG_WRITE_SEQ_P: {
        uint8_t *ptr = (uint8_t*) arg_ptr;
        while (arg_val > 0) {
          u8g_com_DUE_st7920_write_byte_sw_spi(u8g->pin_list[U8G_PI_A0_STATE], *ptr++);
          arg_val--;
        }
      }
      break;
  }
  return 1;
}

#endif  //ARDUINO_ARCH_SAM