/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Copyright (C) 2007 by Greg White
*
* 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 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "system.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 bool lcd_on = true;
static bool lcd_powered = true;
static unsigned lcd_yuv_options = 0;
/*
** This is imported from lcd-16bit.c
*/
extern struct viewport* current_vp;

/* Copies a rectangle from one framebuffer to another. Can be used in
   single transfer mode with width = num pixels, and height = 1 which
   allows a full-width rectangle to be copied more efficiently. */
extern void lcd_copy_buffer_rect(fb_data *dst, const fb_data *src,
                                 int width, int height);

bool lcd_enabled(void)
{
    return lcd_on;
}

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

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

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

static inline void delay_cycles(volatile int delay)
{
    while(delay>0) delay--;
}

static void LCD_CTRL_setup(void)
{
    /* ENVID = 0, BPPMODE = 16 bpp, PNRMODE = TFT, MMODE = Each Frame, CLKVAL = 8 */
    LCDCON1 = 0x878;

    /* 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;

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

static void LCD_CTRL_clock(bool onoff)
{
    if(onoff)
    {
        GPCCON  &= ~0xFFF000FC;
        GPDCON  &= ~0xFFF0FFF0;

        GPCCON  |= 0xAAA000A8;
        GPCUP   |= 0xFC0E;

        GPDCON  |= 0xAAA0AAA0;
        GPDUP   |= 0xFCFC;

        s3c_regset32(&CLKCON, 0x20);  /* enable LCD clock */
        LCDCON1 |=0x01;
    }
    else
    {
        GPCCON  &= ~0xFFF000FC;
        GPCUP   &= ~0xFC0E;

        GPDCON  &= ~0xFFF0FFF0;
        GPDUP   &= ~0xFCFC;

        LCDCON1 &= ~1;              /* Must diable first or bus may freeze */
        s3c_regclr32(&CLKCON, 0x20);  /* disable LCD clock */
    }
}

static void reset_LCD(bool reset)
{
    GPBCON&=~0xC000;
    GPBCON|=0x4000;
    if(reset)
        GPBDAT|=0x80;
    else
        GPBDAT&=~0x80;
}

static void LCD_SPI_send(const unsigned char *array, int count)
{
    while (count--)       
    {
        while ((SPSTA0&0x01)==0){};
        SPTDAT0=*array++;
    }
}

static void LCD_SPI_setreg(unsigned char reg, unsigned char value)
{
    unsigned char regval[] = 
    {
        0x00,reg,0x01,value
    };
    LCD_SPI_send(regval, sizeof(regval));
}

static void LCD_SPI_SS(bool select)
{
    delay_cycles(0x4FFF);

    GPBCON&=~0x30000;
    GPBCON|=0x10000;

    if(select)
        GPBDAT|=0x100;
    else 
        GPBDAT&=~0x100;
}

static void LCD_SPI_start(void)
{
    s3c_regset32(&CLKCON, 0x40000);   /* enable SPI clock */
    LCD_SPI_SS(false);
    SPCON0=0x3E;
    SPPRE0=24;

    reset_LCD(true);
    LCD_SPI_SS(true);
}

static void LCD_SPI_stop(void)
{
    LCD_SPI_SS(false);

    SPCON0 &= ~0x10;
    s3c_regclr32(&CLKCON, 0x40000);    /* disable SPI clock */  
}

static void LCD_SPI_powerdown(void)
{
    lcd_powered = false;

    LCD_SPI_start();
    LCD_SPI_setreg(0x04, 0x00);
    LCD_SPI_stop();

    reset_LCD(false);   /* This makes a big difference on power */
    LCD_CTRL_clock(false);
} 

static void LCD_SPI_powerup(void)
{
    LCD_CTRL_clock(true);

    LCD_SPI_start();
    LCD_SPI_setreg(0x04, 0x01);
    LCD_SPI_stop();

    lcd_powered = true;
}

static void LCD_SPI_init(void)
{
    /*
     * SPI setup - Some of these registers are known; they are documented in
     *  the wiki.  Many thanks to Alex Gerchanovsky for discovering this
     *  sequence.
     */

    LCD_CTRL_clock(true);

    LCD_SPI_start();
    LCD_SPI_setreg(0x0F, 0x01);
    LCD_SPI_setreg(0x09, 0x06);
    LCD_SPI_setreg(0x16, 0xA6);
    LCD_SPI_setreg(0x1E, 0x49);
    LCD_SPI_setreg(0x1F, 0x26);
    LCD_SPI_setreg(0x0B, 0x2F);
    LCD_SPI_setreg(0x0C, 0x2B);
    LCD_SPI_setreg(0x19, 0x5E);
    LCD_SPI_setreg(0x1A, 0x15);
    LCD_SPI_setreg(0x1B, 0x15);
    LCD_SPI_setreg(0x1D, 0x01);
    LCD_SPI_setreg(0x00, 0x03);
    LCD_SPI_setreg(0x01, 0x10);
    LCD_SPI_setreg(0x02, 0x0A);
    LCD_SPI_setreg(0x06, 0x04); /* Set the orientation */
    LCD_SPI_setreg(0x08, 0x2E);
    LCD_SPI_setreg(0x24, 0x12);
    LCD_SPI_setreg(0x25, 0x3F);
    LCD_SPI_setreg(0x26, 0x0B);
    LCD_SPI_setreg(0x27, 0x00);
    LCD_SPI_setreg(0x28, 0x00);
    LCD_SPI_setreg(0x29, 0xF6);
    LCD_SPI_setreg(0x2A, 0x03);
    LCD_SPI_setreg(0x2B, 0x0A);
    LCD_SPI_setreg(0x04, 0x01); /* Turn the display on */
    LCD_SPI_stop(); 
}

/* LCD init */
void lcd_init_device(void)
{
#ifdef BOOTLOADER
    int i;
    /* 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


    /* Set pins up */

    GPHUP   &= 0x600;

    GPECON  |= 0x0A800000;
    GPEUP   |= 0x3800;

    GPBUP   |= 0x181;

    s3c_regset32(&CLKCON, 0x20);  /* enable LCD clock */

    LCD_CTRL_setup();
    LCD_SPI_init();
}

void lcd_sleep(void)
{
    if (lcd_powered)
    {
        /* "not powered" implies "disabled" */
        if (lcd_on)
            lcd_enable(false);

        LCD_SPI_powerdown();
    }
}

void lcd_enable(bool state)
{
    if (state == lcd_on)
        return;

    if(state)
    {
        /* "enabled" implies "powered" */
        if (!lcd_powered)
        {
            LCD_SPI_powerup();
            /* Wait long enough for a frame to be written - yes, it
             * takes awhile. */
            sleep(HZ/5);
        }

        lcd_on = true;
        lcd_update();
        lcd_call_enable_hook();
    }
    else 
    {
        lcd_on = false;
    }
}

void lcd_set_flip(bool yesno) {
    if (!lcd_on)
        return;

    LCD_SPI_start();
    if(yesno)
    {
        LCD_SPI_setreg(0x06, 0x02);
    }
    else 
    {
        LCD_SPI_setreg(0x06, 0x04);
    }
    LCD_SPI_stop();
}

int lcd_default_contrast(void)
{
    return DEFAULT_CONTRAST_SETTING;
}

void lcd_set_contrast(int val) {
    if (!lcd_on)
        return;

    LCD_SPI_start();
    LCD_SPI_setreg(0x0B, (unsigned char) val);
    LCD_SPI_stop();
}

void lcd_set_invert_display(bool yesno) {
    if (!lcd_on)
        return;

    LCD_SPI_start();
    if(yesno)
    {
        LCD_SPI_setreg(0x27, 0x10);
    }
    else 
    {
        LCD_SPI_setreg(0x27, 0x00);
    }
    LCD_SPI_stop();
}

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

    if (!lcd_on)
        return;

    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x; /* Clip right */
    if (x < 0)
        width += x, x = 0; /* Clip left */
    if (width <= 0)
        return; /* nothing left to do */

    if (y + height > LCD_HEIGHT)
        height = LCD_HEIGHT - y; /* Clip bottom */
    if (y < 0)
        height += y, y = 0; /* Clip top */
    if (height <= 0)
        return; /* nothing left to do */

    /* TODO: It may be faster to swap the addresses of lcd_driver_framebuffer
     * and lcd_framebuffer */
    dst = (fb_data *)FRAME + LCD_WIDTH*y + x;
    src = &lcd_framebuffer[y][x];

    /* Copy part of the Rockbox framebuffer to the second framebuffer */
    if (width < LCD_WIDTH)
    {
        /* Not full width - do line-by-line */
        lcd_copy_buffer_rect(dst, src, width, height);
    }
    else
    {
        /* Full width - copy as one line */
        lcd_copy_buffer_rect(dst, src, LCD_WIDTH*height, 1);
    }
}

/* Update the display.
   This must be called after all other LCD functions that change the display. */
void lcd_update(void)
{
    if (!lcd_on)
        return;

    lcd_copy_buffer_rect((fb_data *)FRAME, &lcd_framebuffer[0][0],
                         LCD_WIDTH*LCD_HEIGHT, 1);
}

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)
{
    int w, px;
    fb_data *dst;

    if (x + width > current_vp->width)
        width = current_vp->width - x; /* Clip right */
    if (x < 0)
        width += x, x = 0; /* Clip left */
    if (width <= 0)
        return; /* nothing left to do */

    if (y + height > current_vp->height)
        height = current_vp->height - y; /* Clip bottom */
    if (y < 0)
        height += y, y = 0; /* Clip top */
    if (height <= 0)
        return; /* nothing left to do */

    src += stride * src_y + src_x; /* move starting point */
    dst = &lcd_framebuffer[current_vp->y+y][current_vp->x+x];

    asm volatile (
    ".rowstart:                             \r\n"
        "mov    %[w], %[width]              \r\n" /* Load width for inner loop */
    ".nextpixel:                            \r\n"
        "ldrh   %[px], [%[s]], #2           \r\n" /* Load src pixel */
        "add    %[d], %[d], #2              \r\n" /* Uncoditionally increment dst */
        "cmp    %[px], %[fgcolor]           \r\n" /* Compare to foreground color */
        "streqh %[fgpat], [%[d], #-2]       \r\n" /* Store foregroud if match */
        "cmpne  %[px], %[transcolor]        \r\n" /* Compare to transparent color */
        "strneh %[px], [%[d], #-2]          \r\n" /* Store dst if not transparent */
        "subs   %[w], %[w], #1              \r\n" /* Width counter has run down? */
        "bgt    .nextpixel                  \r\n" /* More in this row? */
        "add    %[s], %[s], %[sstp], lsl #1 \r\n" /* Skip over to start of next line */
        "add    %[d], %[d], %[dstp], lsl #1 \r\n"
        "subs   %[h], %[h], #1              \r\n" /* Height counter has run down? */
        "bgt    .rowstart                   \r\n" /* More rows? */
        : [w]"=&r"(w), [h]"+&r"(height), [px]"=&r"(px),
          [s]"+&r"(src), [d]"+&r"(dst)
        : [width]"r"(width),
          [sstp]"r"(stride - width),
          [dstp]"r"(LCD_WIDTH - width),
          [transcolor]"r"(TRANSPARENT_COLOR),
          [fgcolor]"r"(REPLACEWITHFG_COLOR),
          [fgpat]"r"(current_vp->fg_pattern)
    );
}

void lcd_yuv_set_options(unsigned options)
{
    lcd_yuv_options = options;
}

/* Line write helper function for lcd_yuv_blit. Write two lines of yuv420. */
extern void lcd_write_yuv420_lines(fb_data *dst,
                                   unsigned char const * const src[3],
                                   int width,
                                   int stride);
extern void lcd_write_yuv420_lines_odither(fb_data *dst,
                                           unsigned char const * const src[3],
                                           int width,
                                           int stride,
                                           int x_screen, /* To align dither pattern */
                                           int y_screen);
/* 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_blit_yuv(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 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;

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

    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]);

    if (lcd_yuv_options & LCD_YUV_DITHER)
    {
        do
        {
            lcd_write_yuv420_lines_odither(dst, yuv_src, width, stride, y, x);
            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;
            y -= 2;
        }
        while (--height > 0);
    }
    else
    {
        do
        {
            lcd_write_yuv420_lines(dst, 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);
    }
}