/**
 * SSD1306xLED - Library for the SSD1306 based OLED/PLED 128x64 displays
 *
 * @author Neven Boyanov
 *
 * This is part of the Tinusaur/SSD1306xLED project.
 *
 * Copyright (c) 2018 Neven Boyanov, The Tinusaur Team. All Rights Reserved.
 * Distributed as open source software under MIT License, see LICENSE.txt file.
 * Retain in your source code the link http://tinusaur.org to the Tinusaur project.
 *
 * Source code available at: https://bitbucket.org/tinusaur/ssd1306xled
 *
 */

// ============================================================================
// ACKNOWLEDGEMENTS:
// - Some code and ideas initially based on "IIC_wtihout_ACK"
//   by http://www.14blog.com/archives/1358 (defunct)
// - Init sequence used info from Adafruit_SSD1306.cpp init code.
// ============================================================================

#if defined(__GNUC__)
#include <stdlib.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#elif defined(__ICCAVR__)
# include <ioavr.h>
# include <intrinsics.h>
# include <stdint.h>
#define PROGMEM __flash
#define pgm_read_byte(a)  (*(unsigned char __flash *)(a))
#define pgm_read_word(a)  (*(unsigned __flash *)(a))
#endif

#include "ssd1306xled.h"
#include "i2c.h"

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

void ssd1306_start_command(void);	// Initiate transmission of command
void ssd1306_start_data(void);	// Initiate transmission of data
void ssd1306_data_byte(uint8_t);	// Transmission 1 byte of data
void ssd1306_stop(void);	// Finish transmission

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

const uint8_t PROGMEM ssd1306_init_sequence [] = {	// Initialization Sequence

  0xAE,			// Set Display ON/OFF - AE=OFF, AF=ON
  0xD5, 0xF0,		// Set display clock divide ratio/oscillator frequency, set divide ratio
  0xA8, 0x3F,		// Set multiplex ratio (1 to 64) ... (height - 1)
  0xD3, 0x00,		// Set display offset. 00 = no offset
  0x40 | 0x00,	// Set start line address, at 0.
  0x8D, 0x14,		// Charge Pump Setting, 14h = Enable Charge Pump
  0x20, 0x00,		// Set Memory Addressing Mode - 00=Horizontal, 01=Vertical, 10=Page, 11=Invalid
  0xA0 | 0x01,	// Set Segment Re-map
  0xC8,			// Set COM Output Scan Direction
  0xDA, 0x12,		// Set COM Pins Hardware Configuration - 128x32:0x02, 128x64:0x12
  0x81, 0x3F,		// Set contrast control register
  0xD9, 0x22,		// Set pre-charge period (0x22 or 0xF1)
  0xDB, 0x20,		// Set Vcomh Deselect Level - 0x00: 0.65 x VCC, 0x20: 0.77 x VCC (RESET), 0x30: 0.83 x VCC
  0xA4,			// Entire Display ON (resume) - output RAM to display
  0xA6,			// Set Normal/Inverse Display mode. A6=Normal; A7=Inverse
  0x2E,			// Deactivate Scroll command
  0xAF,			// Set Display ON/OFF - AE=OFF, AF=ON
  //
  0x22, 0x00, 0x3f,	// Set Page Address (start,end)
  0x21, 0x00,	0x7f,	// Set Column Address (start,end)
  //
  // 0xD6, 0x01,		// Set Zoom In, 0=disabled, 1=enabled
  /*
  	0xAE,			// Display OFF (sleep mode)
  	0x20, 0x00,		// Set Memory Addressing Mode - 00=Horizontal, 01=Vertical, , 10=Page, 11=Invalid
  	0xB0,			// Set Page Start Address for Page Addressing Mode, 0-7
  	0xC8,			// Set COM Output Scan Direction
  	0x00,			// ---set low column address
  	0x10,			// ---set high column address
  	0x40,			// --set start line address
  	0x81, 0x3F,		// Set contrast control register
  	0xA1,			// Set Segment Re-map. A0=address mapped; A1=address 127 mapped.
  	0xA6,			// Set display mode. A6=Normal; A7=Inverse
  	0xA8, 0x3F,		// Set multiplex ratio(1 to 64)
  	0xA4,			// Output RAM to Display - 0xA4=Output follows RAM content; 0xA5,Output ignores RAM content
  	0xD3, 0x00,		// Set display offset. 00 = no offset
  	0xD5, 0xF0,		// --set display clock divide ratio/oscillator frequency
  	0xD9, 0x22,		// Set pre-charge period
  	0xDA, 0x12,		// Set com pins hardware configuration
  	0xDB, 0x20,		// --set vcomh, 0x20,0.77xVcc
  	0x8D, 0x14,		// Charge Pump Setting, 14h = Enable Charge Pump
  	0xAF,			// Display ON in normal mode
  */
};

// ============================================================================

// NOTE: These functions are separate sub-library for handling I2C simplified output.
// NAME: I2CSW - I2C Simple Writer.
// Convenience definitions for manipulating PORTB pins
// NOTE: These definitions are used only internally by the I2CSW library
#define I2CSW_HIGH(PORT) PORTB |= (1 << PORT)
#define I2CSW_LOW(PORT) PORTB &= ~(1 << PORT)

// TO-DO: Implement and use the definitions below.
#define I2CSW_SDA_DDI()		// Data direction INPUT (0x17 is DDRB)
#define I2CSW_SDA_DDO()		// Data direction OUTPUT
#define I2CSW_SDA_HI()		// Port to HIGH
#define I2CSW_SDA_LO()		// Port to LOW
#define I2CSW_SCL_DDI()		// Data direction INPUT
#define I2CSW_SCL_DDO()		// Data direction OUTPUTT
#define I2CSW_SCL_HI()		// Port to HIGH
#define I2CSW_SCL_LO()		// Port to LOW
// IMPORTANT/NOTE: There is no need to use AVR ASM instructions such as "cbi" and "sbi"
// The compiler optimizes the bit-shift operations to those instructions.

// ============================================================================

void ssd1306_start_command(void)
{
  I2C_Start();
  I2C_WriteByte(SSD1306_SADDR);	// Slave address: R/W(SA0)=0 - write
  I2C_WriteByte(0x00);			// Control byte: D/C=0 - write command
}

void ssd1306_start_data(void)
{
  I2C_Start();
  I2C_WriteByte(SSD1306_SADDR);	// Slave address, R/W(SA0)=0 - write
  I2C_WriteByte(0x40);			// Control byte: D/C=1 - write data
}

void ssd1306_data_byte(uint8_t b)
{
  I2C_WriteByte(b);
}

void ssd1306_stop(void)
{
  I2C_Stop();
}

// ============================================================================

void ssd1306_init(void)
{
  ssd1306_start_command();	// Initiate transmission of command
  for (uint8_t i = 0; i < sizeof (ssd1306_init_sequence); i++) {
    ssd1306_data_byte(pgm_read_byte(&ssd1306_init_sequence[i]));	// Send the command out
  }
  ssd1306_stop();	// Finish transmission of data
}

void ssd1306_setpos(uint8_t x, uint8_t y)
{
  ssd1306_start_command();
  ssd1306_data_byte(0xb0 | (y & 0x07));	// Set page start address
  ssd1306_data_byte(x & 0x0f);			// Set the lower nibble of the column start address
  ssd1306_data_byte(0x10 | (x >> 4));		// Set the higher nibble of the column start address
  ssd1306_stop();	// Finish transmission of data
}

void ssd1306_fill(uint8_t p)
{
  ssd1306_setpos(0, 0);
  ssd1306_start_data(); // Initiate transmission of data
  for (uint16_t i = 128 * 8; i > 0; i--) {
    ssd1306_data_byte(p);
  }
  ssd1306_stop(); // Finish transmission of data
}

void ssd1306_fill4(uint8_t p1, uint8_t p2, uint8_t p3, uint8_t p4)
{
  ssd1306_setpos(0, 0);
  ssd1306_start_data();	// Initiate transmission of data
  for (uint16_t i = 0; i < 128 * 8 / 4; i++) {
    ssd1306_data_byte(p1);
    ssd1306_data_byte(p2);
    ssd1306_data_byte(p3);
    ssd1306_data_byte(p4);
  }
  ssd1306_stop();	// Finish transmission of data
}

// ============================================================================