/**
 * (C) Copyright Collin J. Doering 2015
 *
 * 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/>.
*/

/**
 * File: lcdLib.h
 * Author: Collin J. Doering <collin.doering@rekahsoft.ca>
 * Date: Sep 29, 2015
 */

/*
  Usage
  =====

  Operates in 3 mutually exclusive modes:
  1. Default Mode
     8-bit mode that requires all its data bus lines be on the same PORT.
  2. EIGHT_BIT_ARBITRARY_PIN_MODE
     8-bit mode that allows the data bus lines to use any IO pin.
  3. FOUR_BIT_MODE
     4-bit mode that allows the data bus lines to use any IO pin.
 */

// Includes -------------------------------------------------------------------------------

#include <avr/io.h>

//------------------------------------------------------------------------------------------

/*
  Screen characteristics (unused) TODO
*/

#define LCD_NUMBER_OF_LINES     2
#define LCD_CHARACTERS_PER_LINE 20

#define LCD_CHARACTER_FONT


/* Modes */

// Default mode: 8-bit data bus

// 8-bit mode with data bus on arbitrary pins
//#define EIGHT_BIT_ARBITRARY_PIN_MODE

// LCD in 4-bit mode (default is 8 bit mode)
//#define FOUR_BIT_MODE

// Mode sanity check
#if defined (EIGHT_BIT_ARBITRARY_PIN_MODE) && defined (FOUR_BIT_MODE)
#error "EIGHT_BIT_ARBITRARY_PIN_MODE and FOUR_BIT_MODE are mutually exclusive. Choose one."
#endif


/* All mode options */

#define LCD_RS          PD2
#define LCD_RS_PORT     PORTD
#define LCD_RS_DDR      DDRD

#define LCD_RW          PD3
#define LCD_RW_PORT     PORTD
#define LCD_RW_DDR      DDRD

#define LCD_ENABLE      PD4
#define LCD_ENABLE_PORT PORTD
#define LCD_ENABLE_DDR  DDRD

/*
  Mode specific settings
*/

/* Default Mode */

// LCD data bus PORT, PIN and DDR.
#define LCD_DBUS_PORT PORTB

#define LCD_DBUS_DDR  DDRB
#define LCD_DBUS_PIN  PINB

// This must be set in default mode to the MSB of the data lines
#define LCD_BF        PB7


/* EIGHT_BIT_ARBITRARY_PIN_MODE specific settings */

#ifdef EIGHT_BIT_ARBITRARY_PIN_MODE
#define LCD_DBUS0      PB0
#define LCD_DBUS0_PORT PORTB
#define LCD_DBUS0_DDR  DDRB
#define LCD_DBUS0_PIN  PINB

#define LCD_DBUS1      PB1
#define LCD_DBUS1_PORT PORTB
#define LCD_DBUS1_DDR  DDRB
#define LCD_DBUS1_PIN  PINB

#define LCD_DBUS2      PB2
#define LCD_DBUS2_PORT PORTB
#define LCD_DBUS2_DDR  DDRB
#define LCD_DBUS2_PIN  PINB

#define LCD_DBUS3      PB3
#define LCD_DBUS3_PORT PORTB
#define LCD_DBUS3_DDR  DDRB
#define LCD_DBUS3_PIN  PINB
#endif

/* FOUR_BIT_MODE and EIGHT_BIT_ARBITRARY_PIN_MODE shared settings */

#if defined (FOUR_BIT_MODE) || defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
#define LCD_DBUS4      PB4
#define LCD_DBUS4_PORT PORTB
#define LCD_DBUS4_DDR  DDRB
#define LCD_DBUS4_PIN  PINB

#define LCD_DBUS5      PB5
#define LCD_DBUS5_PORT PORTB
#define LCD_DBUS5_DDR  DDRB
#define LCD_DBUS5_PIN  PINB

#define LCD_DBUS6      PB6
#define LCD_DBUS6_PORT PORTB
#define LCD_DBUS6_DDR  DDRB
#define LCD_DBUS6_PIN  PINB

#define LCD_DBUS7      PB7
#define LCD_DBUS7_PORT PORTB
#define LCD_DBUS7_DDR  DDRB
#define LCD_DBUS7_PIN  PINB
#endif

#if defined (FOUR_BIT_MODE) || defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
#undef  LCD_BF
#define LCD_BF         LCD_DBUS7
#endif


/* LCD delays (in microseconds when unspecified) */

#define LCD_ENABLE_HIGH_DELAY   25
#define LCD_ENABLE_LOW_DELAY    25
#define LCD_INIT_DELAY0         15000
#define LCD_INIT_DELAY1         8200
#define LCD_INIT_DELAY2         200

#define LCD_CLEAR_DISPLAY_DELAY 16000
#define LCD_RETURN_HOME_DELAY   16000
#define LCD_GENERIC_INSTR_DELAY 50


/* LCD Commands */

// Simple commands with no options
#define CMD_INIT             0x30
#define CMD_INIT_FOUR_BIT    0x20
#define CMD_CLEAR_DISPLAY    0x01
#define CMD_RETURN_HOME      0x02

// Entry Set instruction and associated options
#define INSTR_ENTRY_SET      0x04
#define INSTR_ENTRY_SET_ID   1
#define INSTR_ENTRY_SET_S    0

// Display control instruction and associated options
#define INSTR_DISPLAY        0x08
#define INSTR_DISPLAY_D      2
#define INSTR_DISPLAY_C      1
#define INSTR_DISPLAY_B      0

// Cursor or display shift instruction and associated options
#define INSTR_MOV_SHIFT      0x10
#define INSTR_MOV_SHIFT_SC   0x08
#define INSTR_MOV_SHIFT_RL   0x04

// Function set instruction and associated options
#define INSTR_FUNC_SET       0x20
#define INSTR_FUNC_SET_DL    4
#define INSTR_FUNC_SET_N     3
#define INSTR_FUNC_SET_F     2

// Set CG RAM address instruction
#define INSTR_CGRAM_ADDR     0x60

// Set DD RAM address instruction
#define INSTR_DDRAM_ADDR     0x80


//------------------------------------

#define STATUS_LED_PORT PORTC
#define STATUS_LED_DDR  DDRC
#define STATUS_LED      PC5

// Function definitions
void flashLED(uint8_t times);

//------------------------------------

void clkLCD(void);

void loop_until_LCD_BF_clear(void);

#ifdef FOUR_BIT_MODE
void writeLCDNibble_(uint8_t);
#endif

void writeLCDByte_(uint8_t);

void writeLCDInstr_(uint8_t);

void writeLCDInstr(uint8_t);

void writeCharToLCD_(char);

void writeCharToLCD(char);

void writeStringToLCD(const char*);

void clearDisplay(void);

void returnHome(void);

char readCharFromLCD(void);

/*
  Do software initialization as specified by the datasheet
*/
void initLCD(void);

void initLCDByInternalReset(void);