text: /*
  
    u8g_arduino_fast_parallel.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.
  
    PIN_D0 8
    PIN_D1 9
    PIN_D2 10
    PIN_D3 11
    PIN_D4 4
    PIN_D5 5
    PIN_D6 6
    PIN_D7 7
  
    PIN_CS1 14
    PIN_CS2 15
    PIN_RW 16
    PIN_DI 17
    PIN_EN 18
  
    u8g_Init8Bit(u8g, dev, d0, d1, d2, d3, d4, d5, d6, d7, en, cs1, cs2, di, rw, reset)
    u8g_Init8Bit(u8g, dev,  8,    9, 10, 11,   4,   5,   6,   7, 18, 14, 15, 17, 16, U8G_PIN_NONE)
  
    Update for ATOMIC operation done (01 Jun 2013)
      U8G_ATOMIC_OR(ptr, val)
      U8G_ATOMIC_AND(ptr, val)
      U8G_ATOMIC_START();
      U8G_ATOMIC_END();
  
  */
  
  #include "u8g.h"
  
  #if defined(ARDUINO) && !defined(ARDUINO_ARCH_STM32)
  
  #if ARDUINO < 100
  //#include <WProgram.h>
  #include <wiring_private.h>
  #include <pins_arduino.h>
  #else
  #include <Arduino.h>
  #endif
  
  
  #define PIN_D0 8
  #define PIN_D1 9
  #define PIN_D2 10
  #define PIN_D3 11
  #define PIN_D4 4
  #define PIN_D5 5
  #define PIN_D6 6
  #define PIN_D7 7
  
  #define PIN_CS1 14
  #define PIN_CS2 15
  #define PIN_RW 16
  #define PIN_DI 17
  #define PIN_EN 18
  
  //#define PIN_RESET
  
  
  #ifdef __PIC32MX
  /* CHIPKIT PIC32 */
  typedef uint32_t u8g_data_t;
  #else
  typedef uint8_t u8g_data_t;
  #endif
  typedef u8g_data_t* u8g_ptr_t;
  static volatile u8g_ptr_t u8g_data_port[8];
  static u8g_data_t u8g_data_mask[8];
  
  
  
  static void u8g_com_arduino_fast_parallel_init(u8g_t *u8g)
  {
    u8g_data_port[0] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D0]));
    u8g_data_mask[0] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D0]);
    u8g_data_port[1] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D1]));
    u8g_data_mask[1] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D1]);
    u8g_data_port[2] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D2]));
    u8g_data_mask[2] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D2]);
    u8g_data_port[3] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D3]));
    u8g_data_mask[3] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D3]);
  
    u8g_data_port[4] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D4]));
    u8g_data_mask[4] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D4]);
    u8g_data_port[5] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D5]));
    u8g_data_mask[5] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D5]);
    u8g_data_port[6] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D6]));
    u8g_data_mask[6] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D6]);
    u8g_data_port[7] = (u8g_ptr_t)portOutputRegister(digitalPinToPort(u8g->pin_list[U8G_PI_D7]));
    u8g_data_mask[7] = (u8g_data_t)digitalPinToBitMask(u8g->pin_list[U8G_PI_D7]);
  }
  
  /* atomic protection must be done by calling function */
  static void u8g_com_arduino_fast_write_data_pin(uint8_t pin, uint8_t val)
  {
    if ( val != 0 )
      *u8g_data_port[pin] |= u8g_data_mask[pin];
    else
      *u8g_data_port[pin] &= ~u8g_data_mask[pin];
  }
  
  
  void u8g_com_arduino_fast_parallel_write(u8g_t *u8g, uint8_t val)
  {
    U8G_ATOMIC_START();
    u8g_com_arduino_fast_write_data_pin( 0, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 1, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 2, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 3, val&1 );
    val >>= 1;
  
    u8g_com_arduino_fast_write_data_pin( 4, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 5, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 6, val&1 );
    val >>= 1;
    u8g_com_arduino_fast_write_data_pin( 7, val&1 );
    val >>= 1;
    U8G_ATOMIC_END();
  
    /* EN cycle time must be 1 micro second */
    u8g_com_arduino_digital_write(u8g, U8G_PI_EN, HIGH);
    u8g_MicroDelay(); /* delay by 1000ns, reference: ST7920: 140ns, SBN1661: 100ns */
    u8g_com_arduino_digital_write(u8g, U8G_PI_EN, LOW);
    u8g_10MicroDelay(); /* ST7920 commands: 72us */
    u8g_10MicroDelay(); /* ST7920 commands: 72us */
  }
  
  
  uint8_t u8g_com_arduino_fast_parallel_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
  {
    switch(msg)
    {
      case U8G_COM_MSG_INIT:
        u8g_com_arduino_fast_parallel_init(u8g);
        /* setup the RW pin as output and force it to low */
        if ( u8g->pin_list[U8G_PI_RW] != U8G_PIN_NONE )
        {
          pinMode(u8g->pin_list[U8G_PI_RW], OUTPUT);
          u8g_com_arduino_digital_write(u8g, U8G_PI_RW, LOW);
        }
        /* set all pins (except RW pin) */
        u8g_com_arduino_assign_pin_output_high(u8g);
        break;
      case U8G_COM_MSG_STOP:
        break;
  
      case U8G_COM_MSG_CHIP_SELECT:
        if ( arg_val == 0 )
        {
          /* disable */
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS1, HIGH);
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS2, HIGH);
        }
        else if ( arg_val == 1 )
        {
          /* enable */
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS1, LOW);
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS2, HIGH);
        }
        else if ( arg_val == 2 )
        {
          /* enable */
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS1, HIGH);
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS2, LOW);
        }
        else
        {
          /* enable */
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS1, LOW);
          u8g_com_arduino_digital_write(u8g, U8G_PI_CS2, LOW);
        }
        break;
      case U8G_COM_MSG_WRITE_BYTE:
        u8g_com_arduino_fast_parallel_write(u8g, arg_val);
        break;
      case U8G_COM_MSG_WRITE_SEQ:
        {
          register uint8_t *ptr = arg_ptr;
          while( arg_val > 0 )
          {
            u8g_com_arduino_fast_parallel_write(u8g, *ptr++);
            arg_val--;
          }
        }
        break;
      case U8G_COM_MSG_WRITE_SEQ_P:
        {
          register uint8_t *ptr = arg_ptr;
          while( arg_val > 0 )
          {
            u8g_com_arduino_fast_parallel_write(u8g, u8g_pgm_read(ptr));
            ptr++;
            arg_val--;
          }
        }
        break;
      case U8G_COM_MSG_ADDRESS:                     /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
        u8g_com_arduino_digital_write(u8g, U8G_PI_DI, arg_val);
        break;
      case U8G_COM_MSG_RESET:
        if ( u8g->pin_list[U8G_PI_RESET] != U8G_PIN_NONE )
          u8g_com_arduino_digital_write(u8g, U8G_PI_RESET, arg_val);
        break;
  
    }
    return 1;
  }
  
  #else
  
  
  uint8_t u8g_com_arduino_fast_parallel_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
  {
    return 1;
  }
  
  
  #endif /* ARDUINO */
  