// LCD-Ansteuerung Low Level
// Achtung!!! Controller ist der ILI9325, die Angabe im Datenblatt des Displays ist falsch!!!!!

#include "LCD.h"
#include "stm32f446xx.h"
#include "stdlib.h"
#include "cpu_init.h"

/* LCD Ports
 * D0: PA9
 * D1: PC7
 * D2: PA10
 * D3: PB3
 * D4: PB5
 * D5: PB4
 * D6: PB10
 * D7: PA8
 * RST: PC1 (High aktiv)
 * CS: PB0
 * RS: PA4
 * WR: PA1
 * RD: PA0
 *
 *
 */

uint8_t LCD_getPortBits(void)
{
	return (uint8_t)(((GPIOA->IDR & 0x100) >> 1) // D7
			+ ((GPIOA->IDR & 0x200) >> 9) 	     // D0
			+ ((GPIOA->IDR & 0x400) >> 8) 	     // D2
			+ ((GPIOB->IDR & 0x8))      	     // D3
			+ ((GPIOB->IDR & 0x10) << 1) 	     // D5
			+ ((GPIOB->IDR & 0x20) >> 1) 	     // D4
			+ ((GPIOB->IDR & 0x400) >> 4) 	     // D6
			+ ((GPIOC->IDR & 0x80) >> 6)); 	     // D1
}

// Hilfsfunktion zum Setzen der Datenbits auf den Port
void LCD_setPortBits(uint32_t data)
{
	// Portbits PA8, PA9, PA10 löschen
	GPIOA->BSRR = 0x07000000;
	// PA8, 9, 10 entsprechend zu schreibendem Byte setzen (D0, D2, D7, RD high
	GPIOA->BSRR = ((data & 1)<< 9) + ((data & 4)<< 8) + ((data & 128)<< 1) + 1;
	// Portbits PB3, PB4, PB5, PB10 löschen
	GPIOB->BSRR = 0x04380000;
	// PB 3,4,5,10 entsprechend Daten setzen
	GPIOB->BSRR = ((data & 8)) + ((data & 16)<< 1) + ((data & 32)>> 1) + ((data & 64)<< 4);
	// Portbits PC7 löschen
	GPIOC->BSRR = 0x00800000;
	// PC7 entsprechend Daten setzen
	GPIOC->BSRR = ((data & 2) << 6);
}

// schaltet Datenbus auf Ausgang
void LCD_enableBus(void)
{
	//PA8,9,10
	GPIOA->MODER = GPIOA->MODER | 0x00150000;
	// PB3,4,5,10
	GPIOB->MODER = GPIOB->MODER | 0x00100540;
	// PC7
	GPIOC->MODER = GPIOC->MODER | 0x00004000;
}

// schaltet Datenbus auf Eingang
void LCD_disableBus(void)
{
	//PA8,9,10
	GPIOA->MODER = GPIOA->MODER & ~0x00150000;
	// PB3,4,5,10
	GPIOB->MODER = GPIOB->MODER & ~0x00100540;
	// PC7
	GPIOC->MODER = GPIOC->MODER & ~0x00004000;
}

// CS low oder high setzen
void LCD_setCS(int Level)
{
	if (Level == 0)
		GPIOB->BSRR = 0x10000; // CS low
	else
		GPIOB->BSRR = 1; // CS high
}

// Byte schreiben, wahlweise als Kommando (0) oder Daten (1)
void LCD_writeByte(uint8_t data, int cmd_data)
{
	if (cmd_data == 0)
		GPIOA->BSRR = 0x100000; // RS low

	LCD_setPortBits(data);
	LCD_enableBus();
	GPIOA->BSRR = 0x20000; // WR low
	//GPIOA->BSRR = 2;       // WR high
	GPIOA->BSRR = 0x12; // RS high
	LCD_disableBus();
}

// Byte lesen
uint8_t LCD_readByte(void)
{
	volatile int i;

	GPIOA->BSRR = 0x10000; // RD low
	i = LCD_getPortBits();
	GPIOA->BSRR = 1;       // RD high
	return i;
}

/**************************************/

// Touch Screen lesen:
// PB0(IN8): X (RS Low und D0 High), PA4(IN4): Y (CS High und D1 Low)
// zuerst RS auf Low und D0 auf High, CS und D1 floatend, Kanal 4 von ADC2 samplen -> X
// CS auf High und D1 auf Low, RS und D0 floatend, Kanal 8 samplen -> Y

xy_t LCD_getIntTouch(void)
{
	xy_t Result;
	// D0: PA9, D1: PC7, CS: PB0, RS: PA4
	// zuerst D0 auf High, RS auf Low, CS und D1 floatend
	GPIOA->BSRR = 0x100200;      // D0 auf High und RS auf Low
	GPIOA->MODER = GPIOA->MODER | 0x00040100;   // D0 und RS als Ausgang
	GPIOB->MODER = GPIOB->MODER | 3;            // CS als analoger Pin
	// D1 auf Low, danach floatend, um 'Touch' zu erkennen
	GPIOC->BSRR = 0x80;
	GPIOC->MODER = GPIOC->MODER | 0x4000;
	GPIOC->MODER = GPIOC->MODER & ~0x4000;

	// A/D-Wandlung Kanal 8 starten
	ADC2->CR2 = ADC2->CR2 | 0x40000000;
	// wartem, bis Wandlung fertig ist
	while ((ADC2->SR & 2) == 0);
	// Resultat lesen
	Result.y = ADC2->DR;
	// Umschalten auf Kanal 4
	ADC2->SQR3 = 4;
	// CS High, D1 Low, D0 floatend, RS als Analogeingang
	GPIOA->MODER = GPIOA->MODER & ~0x40000;   // D0 floatend
	GPIOC->MODER = GPIOC->MODER | 0x4000;      // D1 als Ausgang
	GPIOC->BSRR = 0x800000;                    // D1 auf Low
	GPIOB->MODER = GPIOB->MODER & ~2;          // CS als Ausgang
	GPIOB->BSRR = 1;                           // CS High
	GPIOA->MODER = GPIOA->MODER | 0x300;       // PA4 analog
	// A/D-Wandlung Kanal 4 starten
	ADC2->CR2 = ADC2->CR2 | 0x40000000;
	// warten, bis Wandlung fertig ist
	while ((ADC2->SR & 2) == 0);
	// Resultat lesen
	Result.x = ADC2->DR;
	// Umschalten auf Kanal 8
	ADC2->SQR3 = 8;
	// RS als Ausgang, D1 floatend
	GPIOA->MODER = GPIOA->MODER & ~0x200;
	GPIOC->MODER = GPIOC->MODER & ~0x4000;
	GPIOA->BSRR = 0x10;  // RS High

	if (Result.y > 3600)
	{	// kein 'Touch'
		Result.x = 32767;
		Result.y = 32767;
	}
	else
	{
		Result.x = 4095 - Result.x;
		Result.y = 4095 - Result.y;
	}
	return Result;
}

/**************************************************************/
// Portunabhängige Funktionen

// falls keine Berührung, ist x und y auf 32767
xy_t LCD_getTouch(void)
{
	xy_t t1, t2, t3;
	const int TOLERANZ = 20;
	const int XMAX = 3850;
	const int YMAX = 3450;
	const int XMIN = 600;
	const int YMIN = 300;
	const int XOFFSET = 34;
	const int YOFFSET = 29;

	LCD_setCS(1);
	do
	{
		t1 = LCD_getIntTouch();
		t2 = LCD_getIntTouch();
		t3 = LCD_getIntTouch();
	} while((abs(t1.x-t2.x) > TOLERANZ) || (abs(t1.y - t2.y) > TOLERANZ)
			|| (abs(t1.x-t3.x) > TOLERANZ) || (abs(t1.y - t3.y) > TOLERANZ));

	if (t1.x != 32767)
	{
		t1.x = t1.x * 320 / (XMAX - XMIN) - XOFFSET;
		t1.y = t1.y * 240 / (YMAX - YMIN) - YOFFSET;
	}
	LCD_setCS(0);
	return t1;
}

void LCD_Write_COM_DATA(uint8_t cmd, uint16_t data)
{
	LCD_writeByte(0, 0);
	LCD_writeByte(cmd, 0); // Kommandobyte
	LCD_writeByte(data >> 8, 1);
	LCD_writeByte(data & 255, 1);
}


// Schreiben eines Pixels (16 Bit Farbe)
void LCD_writePixel(uint16_t color)
{
	LCD_writeByte(color >> 8, 1);
	LCD_writeByte(color & 255, 1);
}

// Adresspointer setzen
void LCD_setXY(uint16_t x, uint16_t y)
{
	LCD_Write_COM_DATA(0x20, y);
	LCD_Write_COM_DATA(0x21, x);
	LCD_writeByte(0, 0);
	LCD_writeByte(0x22, 0);
}

// Adressrange für Rechteck definieren
// Adresspointer wird auf obere linke Ecke gesetzt
void LCD_setRect(uint16_t x1, uint16_t x2, uint16_t y1, uint16_t y2)
{
	uint16_t temp;

	if (x2 < x1)
	{
		temp = x2;
		x2 = x1;
		x1 = temp;
	}
	if (y2 < y1)
	{
		temp = y2;
		y2 = y1;
		y1 = temp;
	}
	LCD_Write_COM_DATA(0x50, y1);
	LCD_Write_COM_DATA(0x51, y2);
	LCD_Write_COM_DATA(0x52, x1);
	LCD_Write_COM_DATA(0x53, x2);
	LCD_Write_COM_DATA(0x20, y1);
	LCD_Write_COM_DATA(0x21, x1);
	LCD_writeByte(0, 0);
	LCD_writeByte(0x22, 0);
}


// Konvertierung RGB nach 16bit-Farbe
uint16_t LCD_getColor(uint8_t R, uint8_t G, uint8_t B)
{
	// Farben auf 5 (6) Bit begrenzen
	R = R >> 3;
	B = B >> 3;
	G = G >> 2;
	return (uint16_t)(B) + ((uint16_t)(G) << 5) + ((uint16_t)(R) << 11);
}

void LCD_init(void)
{
	// Pullup D1 für Touch Screen
	GPIOC->PUPDR = 0x4000;

	LCD_setCS(1);
	// Hardware-Reset
	GPIOC->BSRR = 0x20000;
	delay(100);
	GPIOC->BSRR = 0x2;         // Reset aufheben
	delay(500);
	LCD_setCS(0);

	// Initialisierung 16 Bit Farben (dadurch nur 2 Bytes/Pixel, ergibt schnelleren Update)
	LCD_Write_COM_DATA(0xE5, 0x78F0); // set SRAM internal timing
	LCD_Write_COM_DATA(0x01, 0x0200); // set Driver Output Control  (Bit 10 prüfen, zusammen mit r60)
	LCD_Write_COM_DATA(0x02, 0x0300); // set 1 line inversion
	LCD_Write_COM_DATA(0x03, 0x3038); // set GRAM write direction, BGR = 1, TRI = 0, AM = 1, DFM = 1, ORG = 0, ID=11
	LCD_Write_COM_DATA(0x04, 0x0000); // Resize register
	LCD_Write_COM_DATA(0x08, 0x0207); // set the back porch and front porch
	LCD_Write_COM_DATA(0x09, 0x0000); // set non-display area refresh cycle ISC[3:0]
	LCD_Write_COM_DATA(0x0A, 0x0000); // FMARK function
	LCD_Write_COM_DATA(0x0C, 0x0000); // RGB interface setting
	LCD_Write_COM_DATA(0x0D, 0x0000); // Frame marker Position
	LCD_Write_COM_DATA(0x0F, 0x0000); // RGB interface polarity
	//*************Power On sequence ****************//
	LCD_Write_COM_DATA(0x10, 0x0000); // SAP, BT[3:0], AP, DSTB, SLP, STB
	LCD_Write_COM_DATA(0x11, 0x0007); // DC1[2:0], DC0[2:0], VC[2:0]
	LCD_Write_COM_DATA(0x12, 0x0000); // VREG1OUT voltage
	LCD_Write_COM_DATA(0x13, 0x0000); // VDV[4:0] for VCOM amplitude
	LCD_Write_COM_DATA(0x07, 0x0001);
	delay(200); // Dis-charge capacitor power voltage
	LCD_Write_COM_DATA(0x10, 0x1690); // SAP, BT[3:0], AP, DSTB, SLP, STB
	LCD_Write_COM_DATA(0x11, 0x0227); // Set DC1[2:0], DC0[2:0], VC[2:0]
	delay(50); // Delay 50ms
	LCD_Write_COM_DATA(0x12, 0x000D); // 0012
	delay(50); // Delay 50ms
	LCD_Write_COM_DATA(0x13, 0x1200); // VDV[4:0] for VCOM amplitude
	LCD_Write_COM_DATA(0x29, 0x000A); // 04  VCM[5:0] for VCOMH
	LCD_Write_COM_DATA(0x2B, 0x000D); // Set Frame Rate
	delay(50); // Delay 50ms
	LCD_Write_COM_DATA(0x20,0); // GRAM horizontal Address
	LCD_Write_COM_DATA(0x21,0); // GRAM Vertical Address
	// ----------- Adjust the Gamma Curve ----------//
	LCD_Write_COM_DATA(0x30, 0x0000);
	LCD_Write_COM_DATA(0x31, 0x0404);
	LCD_Write_COM_DATA(0x32, 0x0003);
	LCD_Write_COM_DATA(0x35, 0x0405);
	LCD_Write_COM_DATA(0x36, 0x0808);
	LCD_Write_COM_DATA(0x37, 0x0407);
	LCD_Write_COM_DATA(0x38, 0x0303);
	LCD_Write_COM_DATA(0x39, 0x0707);
	LCD_Write_COM_DATA(0x3C, 0x0504);
	LCD_Write_COM_DATA(0x3D, 0x0808);
	//------------------ Set GRAM area ---------------//
	LCD_Write_COM_DATA(0x50,0); // Horizontal GRAM Start Address
	LCD_Write_COM_DATA(0x51,240-1); // Horizontal GRAM End Address
	LCD_Write_COM_DATA(0x52,0); // Vertical GRAM Start Address
	LCD_Write_COM_DATA(0x53,320-1); // Vertical GRAM Start Address
	LCD_Write_COM_DATA(0x60, 0xa700); // Gate Scan Line
	LCD_Write_COM_DATA(0x61, 0x0001); // NDL,VLE, REV
	LCD_Write_COM_DATA(0x6A, 0x0000); // set scrolling line
	//-------------- Partial Display Control ---------//
	LCD_Write_COM_DATA(0x80, 0x0000);
	LCD_Write_COM_DATA(0x81, 0x0000);
	LCD_Write_COM_DATA(0x82, 0x0000);
	LCD_Write_COM_DATA(0x83, 0x0000);
	LCD_Write_COM_DATA(0x84, 0x0000);
	LCD_Write_COM_DATA(0x85, 0x0000);
	//-------------- Panel Control -------------------//
	LCD_Write_COM_DATA(0x07, 0x0133); // 262K color and display ON

	// Display löschen

	LCD_Write_COM_DATA(0x20,0); // GRAM Vertical Address
	LCD_Write_COM_DATA(0x21,0); // GRAM horizontal Address
	LCD_writeByte(0, 0);
	LCD_writeByte(0x22, 0);
}