#include "config.h"
#include "cpu.h"
#include "string.h"
#include "lcd.h"
#include "kernel.h"
#include "lcd-target.h"

#define LCDADDR(x, y) (&lcd_framebuffer[(y)][(x)])

static volatile bool lcd_on = true;
volatile bool lcd_poweroff = false;
/*
** These are imported from lcd-16bit.c
*/
extern unsigned fg_pattern;
extern unsigned bg_pattern;

bool lcd_enabled()
{
    return lcd_on;
}

unsigned int LCDBANK(unsigned int address)
{
    return ((address >> 22) & 0xff);
}

unsigned int LCDBASEU(unsigned int address)
{
    return (address & ((1 << 22)-1)) >> 1;
}

unsigned int LCDBASEL(unsigned int address)
{
    address += 320*240*2;
    return (address & ((1 << 22)-1)) >> 1;
}


/* LCD init */
void lcd_init_device(void)
{
    int i;
#ifdef BOOTLOADER
    /* When the Rockbox bootloader starts, we are changing framebuffer address,
       but we don't want what's shown on the LCD to change until we do an
       lcd_update(), so copy the data from the old framebuffer to the new one */
    unsigned short *buf = (unsigned short*)FRAME;

    memcpy(FRAME, (short *)((LCDSADDR1)<<1), 320*240*2);

    /* The Rockbox bootloader is transitioning from RGB555I to RGB565 mode
       so convert the frambuffer data accordingly */
    for(i=0; i< 320*240; i++){
        *buf = ((*buf>>1) & 0x1F) | (*buf & 0xffc0);
        buf++;
    }
#endif

    LCDSADDR1 = (LCDBANK((unsigned)FRAME) << 21) | (LCDBASEU((unsigned)FRAME));
    LCDSADDR2 = LCDBASEL((unsigned)FRAME);
    LCDSADDR3 = 0x000000F0;

#if !defined(BOOTLOADER)
    lcd_poweroff = false;
#endif

    /* ENVID = 1, BPPMODE = 16 bpp, PNRMODE = TFT, MMODE = Each Frame, CLKVAL = 8 */
    LCDCON1 = 0x879;

    /* VCPW = 1, VFPD = 5, LINEVAL = 319, VBPD = 7 */
    LCDCON2 = 0x74FC141;
    
    /* HFPD = 9, HOZVAL = 239, HBPD = 7 */
    LCDCON3 = 0x38EF09;

    /* HSPW = 7 */
    LCDCON4 = 7;
    
    /* HWSWP = 1, INVVFRAM = 1, INVVLINE = 1, FRM565 = 1, All others = 0 */
    LCDCON5 = 0xB01;

    /* LCD controller reset */
    GPBCON = (GPBCON & ~((1<<15)|(1<<17))) | (1<<16)|(1<<14); /* GPB7=OUT, GPB8=OUT */
    GPBDAT |= (1<<7);               /* LCD reset */
    GPBUP  |= (1<<8) | (1<<7) | 1;  /* pullup GPB8, GPB7, GPB0(?) */
    CLKCON |= (1<<5);               /* enable LCD clock */

    /* SPI bus transfer */
    GPBDAT &= ~(1<<8);  /* LCD CS off */

    /* Start the SPI interface */
    CLKCON |= 1<<18;    /* enable SPI clock */
    SPCON0 = 0x3E;      /* enable iterrupt mode, master,active low,format B    */
    SPPRE0 = 0x18;      /* Baud rate = PCLK(50MHz) / 2 / (Prescaler value + 1) */

    /* SPI data - Right now we are not sure what each of these SPI writes is actually
     *    telling the lcd.  Many thanks to Alex Gerchanovsky for discovering them.
     */
    const unsigned char initbuf[] = {
        0,0x0F,1,0x01, 0,0x09,1,0x06, 0,0x16,1,0xA6, 0,0x1E,1,0x49, 0,0x1F,1,0x26, 
        0,0x0B,1,0x2F, 0,0x0C,1,0x2B, 0,0x19,1,0x5E, 0,0x1A,1,0x15, 0,0x1B,1,0x15, 
        0,0x1D,1,0x01, 0,0x00,1,0x03, 0,0x01,1,0x10, 0,0x02,1,0x0A, 0,0x06,1,0x04, 
        0,0x08,1,0x2E, 0,0x24,1,0x12, 0,0x25,1,0x3F, 0,0x26,1,0x0B, 0,0x27,1,0x00,
        0,0x28,1,0x00, 0,0x29,1,0xF6, 0,0x2A,1,0x03, 0,0x2B,1,0x0A, 0,0x04,1,0x01};

    /* Send the SPI data */
    for (i=0;i<(int)sizeof(initbuf);i++)
    {
        while ((SPSTA0&1)==0);
        SPRDAT0 = initbuf[i];
        do{int x;for(x=1000*51/2;x;x--);} while (0);
    }

    /* Stop the SPI interface */
    SPPRE0 = 0;
    SPCON0 = 0;
    CLKCON &= ~(1<<18); /* disable SPI clock */
    GPBDAT |= (1<<8);   /* LCD CS on */
}

/* Update a fraction of the display. */
void lcd_update_rect(int x, int y, int width, int height)
{
    (void)x;
    (void)width;
    (void)y;
    (void)height;

    if(!lcd_on)
    {
        sleep(200);
        return;
    }
    memcpy(((char*)FRAME) + (y * sizeof(fb_data) * LCD_WIDTH), ((char *)&lcd_framebuffer) + (y * sizeof(fb_data) * LCD_WIDTH), ((height * sizeof(fb_data) * LCD_WIDTH)));
}

void lcd_enable(bool state)
{
    if(!lcd_poweroff)
        return;
    if(state)
    {
        if(!lcd_on)
        {
            lcd_on = true;
            memcpy(FRAME, lcd_framebuffer, LCD_WIDTH*LCD_HEIGHT*2);
            LCDCON1 |= 1;
        }
    }
    else 
    {
        if(lcd_on) {
            lcd_on = false;
            LCDCON1 &= ~1;
        }
    }
}

/* Update the display.
   This must be called after all other LCD functions that change the display. */
void lcd_update(void)
{
    lcd_update_rect(0, 0, LCD_WIDTH, LCD_HEIGHT);
}

void lcd_bitmap_transparent_part(const fb_data *src, int src_x, int src_y,
                                 int stride, int x, int y, int width,
                                 int height)
{
    fb_data *dst, *dst_end;
    unsigned int transcolor;

    /* nothing to draw? */
    if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
        || (x + width <= 0) || (y + height <= 0))
        return;

    /* clipping */
    if (x < 0)
    {
        width += x;
        src_x -= x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        src_y -= y;
        y = 0;
    }
    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x;
    if (y + height > LCD_HEIGHT)
        height = LCD_HEIGHT - y;

    src += stride * src_y + src_x; /* move starting point */
    dst = &lcd_framebuffer[(y)][(x)];
    dst_end = dst + height * LCD_WIDTH;
    width *= 2;
    stride *= 2;
    transcolor = TRANSPARENT_COLOR;
    asm volatile(
    "rowstart:  \n"
        "mov    r0, #0  \n"
    "nextpixel:  \n"
        "ldrh   r1, [%0, r0]   \n"  /* Load word src+r0 */
        "cmp    r1, %5 \n"             /* Compare to transparent color */
        "strneh r1, [%1, r0]   \n"  /* Store dst+r0 if not transparent */
        "add    r0, r0, #2  \n"
        "cmp    r0, %2 \n"             /* r0 == width? */         
        "bne    nextpixel \n"        /* More in this row? */
        "add    %0, %0, %4  \n"     /* src += stride */
        "add    %1, %1, #480 \n"    /* dst += LCD_WIDTH (x2) */
        "cmp    %1, %3 \n"             
        "bne    rowstart \n"        /* if(dst != dst_end), keep going */
        : : "r" (src), "r" (dst), "r" (width), "r" (dst_end), "r" (stride), "r" (transcolor) : "r0", "r1" );
}

/* Line write helper function for lcd_yuv_blit. Write two lines of yuv420. */
extern void lcd_write_yuv420_lines(fb_data *dst,
                                   unsigned char chroma_buf[LCD_HEIGHT/2*3],
                                   unsigned char const * const src[3],
                                   int width,
                                   int stride);
/* Performance function to blit a YUV bitmap directly to the LCD */
/* For the Gigabeat - show it rotated */
/* So the LCD_WIDTH is now the height */
void lcd_yuv_blit(unsigned char * const src[3],
                  int src_x, int src_y, int stride,
                  int x, int y, int width, int height)
{
    /* Caches for chroma data so it only need be recaculated every other
       line */
    unsigned char chroma_buf[LCD_HEIGHT/2*3]; /* 480 bytes */
    unsigned char const * yuv_src[3];
    off_t z;

    if (!lcd_on)
        return;

    /* Sorry, but width and height must be >= 2 or else */
    width &= ~1;
    height >>= 1;

    fb_data *dst = (fb_data*)FRAME + x * LCD_WIDTH + (LCD_WIDTH - y) - 1;

    z = stride*src_y;
    yuv_src[0] = src[0] + z + src_x;
    yuv_src[1] = src[1] + (z >> 2) + (src_x >> 1);
    yuv_src[2] = src[2] + (yuv_src[1] - src[1]);

    do
    {
        lcd_write_yuv420_lines(dst, chroma_buf, yuv_src, width,
                               stride);
        yuv_src[0] += stride << 1; /* Skip down two luma lines */
        yuv_src[1] += stride >> 1; /* Skip down one chroma line */
        yuv_src[2] += stride >> 1;
        dst -= 2;
    }
    while (--height > 0);
}

void lcd_set_contrast(int val) {
  (void) val;
  // TODO:
}

void lcd_set_invert_display(bool yesno) {
  (void) yesno;
  // TODO:
}

void lcd_blit(const fb_data* data, int bx, int y, int bwidth,
              int height, int stride)
{
  (void) data;
  (void) bx;
  (void) y;
  (void) bwidth;
  (void) height;
  (void) stride;
  //TODO:
}

void lcd_set_flip(bool yesno) {
  (void) yesno;
  // TODO:
}