#include "stdint.h"
#include "stddef.h"
#include "unistd.h"


#include "io.h"

// LT24 LCD Controller pixel format
typedef struct Pixel
{
    unsigned r : 5;
    unsigned g : 6;
    unsigned b : 5;
} pixel_t;

static inline uint16_t encPixel(const struct Pixel *p)
{
    return (p->r << (5 + 6)) | (p->g << 5) | (p->b);
}

// LT24 LCD Controller hardware address register layout
struct LT24
{
    uint32_t writeReg;
    uint32_t writeData;
    uint32_t writeBase;
    uint32_t refresh;
    uint32_t ctrlReg;
    uint32_t setHeight;
    uint32_t setWidth;
    uint32_t writeIRQ;
    uint32_t setIRQ;
    uint32_t clearIRQ;
    uint32_t isBusy;
} __attribute__((__packed__));


static inline void SleepMS(int someTime)
{
    usleep(1000*someTime);
}

#define LT24_WIDTH 320
#define LT24_HEIGHT 240


// LT24 Interrupt control register
#define LT24_IRQ_CTRL_ENABLE_OFFSET 0
#define LT24_IRQ_CTRL_ENABLE (1 << LT24_IRQ_CTRL_ENABLE_OFFSET)
#define LT24_IRQ_CTRL_CLEAR_ON_REFRESH_OFFSET 1
#define LT24_IRQ_CTRL_CLEAR_ON_REFRESH (1 << LT24_IRQ_CTRL_CLEAR_ON_REFRESH_OFFSET)
#define LT24_IRQ_CTRL_IRQ0_ACTIVE_OFFSET 2
#define LT24_IRQ_CTRL_IRQ0_ACTIVE (1 << LT24_IRQ_CTRL_IRQ0_ACTIVE_OFFSET)

// LT24 Control register
#define LT24_CTRL_LCD_ON_OFFSET 0
#define LT24_CTRL_LCD_ON (1 << LT24_CTRL_LCD_ON_OFFSET)
#define LT24_CTRL_RST_OFFSET 1
#define LT24_CTRL_RST (1 << LT24_CTRL_RST_OFFSET)

// LT24 Read convenience functions
#define LT24_DEFINE_32_RDFUNC(funcname, fieldName)                   \
    static inline uint32_t LT24_##funcname(struct LT24 *lcd)    \
    {                                                                \
        return IORD_32DIRECT(lcd, offsetof(struct LT24, fieldName)); \
    }

LT24_DEFINE_32_RDFUNC(isBusy, isBusy);

// LT24 write convenience functions
#define LT24_DEFINE_16_WRFUNC(funcname, fieldName)                		    \
    static inline void LT24_##funcname(struct LT24 *lcd, uint16_t value)    \
    {																		\
        IOWR_32DIRECT(lcd, offsetof(struct LT24, fieldName), value);		\
    }

LT24_DEFINE_16_WRFUNC(writeReg, writeReg)
LT24_DEFINE_16_WRFUNC(writeData, writeData)
LT24_DEFINE_16_WRFUNC(writeBase, writeBase)
LT24_DEFINE_16_WRFUNC(writeCtrlReg, ctrlReg)
LT24_DEFINE_16_WRFUNC(setHeight, setHeight)
LT24_DEFINE_16_WRFUNC(setWidth, setWidth)
LT24_DEFINE_16_WRFUNC(writeIRQ, writeIRQ)
LT24_DEFINE_16_WRFUNC(setIRQ, setIRQ)
LT24_DEFINE_16_WRFUNC(clearIRQ, clearIRQ)

static inline void LT24_setCursor(struct LT24 *lcd, alt_u16 x, alt_u16 y)
{
	 LT24_writeReg(lcd, 0x002A);
		 LT24_writeData(lcd, x>>8);
		 LT24_writeData(lcd, x&0XFF);
	 LT24_writeReg(lcd, 0x002B);
		 LT24_writeData(lcd, y>>8);
		 LT24_writeData(lcd, y&0XFF);
}

static inline void LT24_refresh(struct LT24 *lcd)
{
    LT24_setCursor(lcd, 0, 0); // Initialize draw position to (0,0)
    LT24_writeReg(lcd, 0x2C); //Memory Write
    IOWR_32DIRECT(lcd, offsetof(struct LT24, refresh), 0);
}

static inline void LT24_manualRefresh(struct LT24 *lcd, uint16_t* buffer, unsigned width, unsigned height)
{
    LT24_setCursor(lcd, 0, 0); // Initialize draw position to (0,0)
    LT24_writeReg(lcd, 0x2C); //Memory Write
    for(int i = 0; i < width*height; i++) {
        LT24_writeData(lcd, *(buffer + i));
    }
}

static inline void LT24_reset(struct LT24 *lcd) {

    LT24_writeCtrlReg(lcd, LT24_CTRL_LCD_ON);
    SleepMS(500);
    LT24_writeCtrlReg(lcd, LT24_CTRL_LCD_ON | LT24_CTRL_RST);
    SleepMS(10);
    LT24_writeCtrlReg(lcd, LT24_CTRL_LCD_ON);
    SleepMS(120);
    LT24_writeReg(lcd, 0x11); //Sleep Out
    SleepMS(10); // Docs: It will be necessary to wait 5msec before sending next to command, this is to allow time for the supply voltages and clock circuits to stabilize
}

static inline void LT24_initialize(struct LT24 *lcd)
{
	LT24_reset(lcd);

    LT24_writeReg(lcd, 0xCF);  //Power Control B
    LT24_writeData(lcd, 0x00); //Always0x00
    LT24_writeData(lcd, 0x81);
    LT24_writeData(lcd, 0xC0);

    LT24_writeReg(lcd, 0xED);  //Power on sequence control
    LT24_writeData(lcd, 0x64); //Soft Start Keep1 frame
    LT24_writeData(lcd, 0x03);
    LT24_writeData(lcd, 0X12);
    LT24_writeData(lcd, 0X81);

    LT24_writeReg(lcd, 0xE8); //Driver timing control A
    LT24_writeData(lcd, 0x85);
    LT24_writeData(lcd, 0x01);
    LT24_writeData(lcd, 0x0798); // 0x00798 ???

    LT24_writeReg(lcd, 0xCB); // Power control A
    LT24_writeData(lcd, 0x39);
    LT24_writeData(lcd, 0x2C);
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x34);
    LT24_writeData(lcd, 0x02);

    LT24_writeReg(lcd, 0xF7); // Pumpratio control
    LT24_writeData(lcd, 0x20);

    LT24_writeReg(lcd, 0xEA); // Driver timing control B
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x00);

    LT24_writeReg(lcd, 0xB1); // Frame Control (In Normal Mode)
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x1b);

    LT24_writeReg(lcd, 0xB6); // Display FunctionControl 
    LT24_writeData(lcd, 0x0A);
    LT24_writeData(lcd, 0xA2);

    LT24_writeReg(lcd, 0xC0);    //Power control 1
    LT24_writeData(lcd, 0x05);   //VRH[5:0]

    LT24_writeReg(lcd, 0xC1);    //Power control 2
    LT24_writeData(lcd, 0x11);   //SAP[2:0];BT[3:0]
    
    LT24_writeReg(lcd, 0xC5);    //VCM control 1
    LT24_writeData(lcd, 0x45);       //3F
    LT24_writeData(lcd, 0x45);       //3C

    LT24_writeReg(lcd, 0xC7); //VCM control 2
    LT24_writeData(lcd, 0xA2);

    LT24_writeReg(lcd, 0x36); //Memory Access Control
    LT24_writeData(lcd, 0x68);

    LT24_writeReg(lcd, 0x2A);  // Column Addr
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x01);
    LT24_writeData(lcd, 0x3F);

    LT24_writeReg(lcd, 0x2B); // Page Addr
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0xF0);

    LT24_writeReg(lcd, 0xF2); //Disable 3Gamma
    LT24_writeData(lcd, 0x00);

    LT24_writeReg(lcd, 0x26); //Gamma Curve Selected
    LT24_writeData(lcd, 0x01);

    LT24_writeReg(lcd, 0xE0); //Positive Gamma Correction, Set Gamma
    LT24_writeData(lcd, 0x0F);
    LT24_writeData(lcd, 0x26);
    LT24_writeData(lcd, 0x24);
    LT24_writeData(lcd, 0x0B);
    LT24_writeData(lcd, 0x0E);
    LT24_writeData(lcd, 0x08);
    LT24_writeData(lcd, 0x4B);
    LT24_writeData(lcd, 0XA8);
    LT24_writeData(lcd, 0x3B);
    LT24_writeData(lcd, 0x0A);
    LT24_writeData(lcd, 0x14);
    LT24_writeData(lcd, 0x06);
    LT24_writeData(lcd, 0x10);
    LT24_writeData(lcd, 0x09);
    LT24_writeData(lcd, 0x00);

    LT24_writeReg(lcd, 0XE1); //NegativeGamma Correction, Set Gamma
    LT24_writeData(lcd, 0x00);
    LT24_writeData(lcd, 0x1C);
    LT24_writeData(lcd, 0x20);
    LT24_writeData(lcd, 0x04);
    LT24_writeData(lcd, 0x10);
    LT24_writeData(lcd, 0x08);
    LT24_writeData(lcd, 0x34);
    LT24_writeData(lcd, 0x47);
    LT24_writeData(lcd, 0x44);
    LT24_writeData(lcd, 0x05);
    LT24_writeData(lcd, 0x0B);
    LT24_writeData(lcd, 0x09);
    LT24_writeData(lcd, 0x2F);
    LT24_writeData(lcd, 0x36);
    LT24_writeData(lcd, 0x0F);

    LT24_writeReg(lcd, 0x3A); //COLMOD: Pixel Format Set
    LT24_writeData(lcd, 0x55);

    LT24_writeReg(lcd, 0xF6); //Interface Control
    LT24_writeData(lcd, 0x01);
    LT24_writeData(lcd, 0x30);
    LT24_writeData(lcd, 0x00);

    LT24_writeReg(lcd, 0x29); //Display on

    LT24_setCursor(lcd, 0, 0); // Initialize draw position to (0,0)

    LT24_writeReg(lcd, 0x2C); //Memory Write
}