/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Rockbox driver for Sansa e200 LCDs
 *
 * Based on reverse engineering done my MrH
 *
 * Copyright (c) 2006 Daniel Ankers
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "config.h"
#include "lcd.h"
#include "system.h"
#include <string.h>

#define LCD_DATA_IN_GPIO GPIOB_INPUT_VAL
#define LCD_DATA_IN_PIN 6

#define LCD_DATA_OUT_GPIO GPIOB_OUTPUT_VAL
#define LCD_DATA_OUT_PIN 7

#define LCD_CLOCK_GPIO GPIOB_OUTPUT_VAL
#define LCD_CLOCK_PIN 5

#define LCD_CS_GPIO GPIOD_OUTPUT_VAL
#define LCD_CS_PIN 6

#define LCD_REG_0 (*(volatile unsigned long *)(0xc2000000))
#define LCD_REG_1 (*(volatile unsigned long *)(0xc2000004))
#define LCD_REG_2 (*(volatile unsigned long *)(0xc2000008))
#define LCD_REG_3 (*(volatile unsigned long *)(0xc200000c))
#define LCD_REG_4 (*(volatile unsigned long *)(0xc2000010))
#define LCD_REG_5 (*(volatile unsigned long *)(0xc2000014))
#define LCD_REG_6 (*(volatile unsigned long *)(0xc2000018))
#define LCD_REG_7 (*(volatile unsigned long *)(0xc200001c))
#define LCD_REG_8 (*(volatile unsigned long *)(0xc2000020))
#define LCD_REG_9 (*(volatile unsigned long *)(0xc2000024))
#define LCD_FB_BASE_REG (*(volatile unsigned long *)(0xc2000028))

/* We don't know how to receive a DMA finished signal from the LCD controller
 * To avoid problems with flickering, we double-buffer the framebuffer and turn
 * off DMA while updates are taking place */
static fb_data lcd_driver_framebuffer[LCD_FBHEIGHT][LCD_FBWIDTH];

static inline void lcd_init_gpio(void)
{
    GPIOB_ENABLE |= (1<<7);
    GPIOB_ENABLE |= (1<<5);
    GPIOB_OUTPUT_EN |= (1<<7);
    GPIOB_OUTPUT_EN |= (1<<5);
    GPIOD_ENABLE |= (1<<6);
    GPIOD_OUTPUT_EN |= (1<<6);
}

static inline void lcd_bus_idle(void)
{
    LCD_CLOCK_GPIO |= (1 << LCD_CLOCK_PIN);
    LCD_DATA_OUT_GPIO |= (1 << LCD_DATA_OUT_PIN);
}

static inline void lcd_send_byte(unsigned char byte)
{

    int i;

    for (i = 7; i >=0 ; i--)
    {
        LCD_CLOCK_GPIO &= ~(1 << LCD_CLOCK_PIN);
        if ((byte >> i) & 1)
        {
            LCD_DATA_OUT_GPIO |= (1 << LCD_DATA_OUT_PIN);
        } else {
            LCD_DATA_OUT_GPIO &= ~(1 << LCD_DATA_OUT_PIN);
        }
        udelay(1);
        LCD_CLOCK_GPIO |= (1 << LCD_CLOCK_PIN);
        udelay(1);
        lcd_bus_idle();
        udelay(3);
    }
}

static inline void lcd_send_msg(unsigned char cmd, unsigned int data)
{
    lcd_bus_idle();
    udelay(1);
    LCD_CS_GPIO &= ~(1 << LCD_CS_PIN);
    udelay(10);
    lcd_send_byte(cmd);
    lcd_send_byte((unsigned char)(data >> 8));
    lcd_send_byte((unsigned char)(data & 0xff));
    LCD_CS_GPIO |= (1 << LCD_CS_PIN);
    udelay(1);
    lcd_bus_idle();
}

static inline void lcd_write_reg(unsigned int reg, unsigned int data)
{
    lcd_send_msg(0x70, reg);
    lcd_send_msg(0x72, data);
}

static inline void cache_flush(void)
{
#ifndef BOOTLOADER
    outl(inl(0xf000f044) | 0x2, 0xf000f044);
    while ((CACHE_CTL & 0x8000) != 0)
    {
    }
#endif
}

/* The LCD controller gets passed the address of the framebuffer, but can only
   use the physical, not the remapped, address.  This is a quick and dirty way
   of correcting it */
static unsigned long phys_fb_address(unsigned long address)
{
    if(address < 0x10000000)
    {
        return address + 0x10000000;
    } else {
        return address;
    }
}

inline void lcd_init_device(void)
{
/* All this is magic worked out by MrH */

/* Stop any DMA which is in progress */
    LCD_REG_6 &= ~1;
    udelay(100000);

/* Init GPIO ports */
    lcd_init_gpio();
/* Controller init */
    outl((inl(0x70000084) | (1 << 28)), 0x70000084);
    outl((inl(0x70000080) & ~(1 << 28)), 0x70000080);
    outl(((inl(0x70000010) & (0x03ffffff)) | (0x15 << 26)), 0x70000010);
    outl(((inl(0x70000014) & (0x0fffffff)) | (0x5 << 28)), 0x70000014);
    outl((inl(0x70000020) & ~(0x3 << 10)), 0x70000020);
    DEV_EN |= (1 << 26); /* Enable controller */
    outl(0x6, 0x600060d0);
    DEV_RS |= (1 << 26); /* Reset controller */
    outl((inl(0x70000020) & ~(1 << 14)), 0x70000020);
    lcd_bus_idle();
    DEV_RS &=~(1 << 26); /* Clear reset */
    udelay(1000);

    LCD_REG_0 = (LCD_REG_0 & (0x00ffffff)) | (0x22 << 24);
    LCD_REG_0 = (LCD_REG_0 & (0xff00ffff)) | (0x14 << 16);
    LCD_REG_0 = (LCD_REG_0 & (0xffffc0ff)) | (0x3 << 8);
    LCD_REG_0 = (LCD_REG_0 & (0xffffffc0)) | (0xa);

    LCD_REG_1 &= 0x00ffffff;
    LCD_REG_1 &= 0xff00ffff;
    LCD_REG_1 = (LCD_REG_1 & 0xffff03ff) | (0x2 << 10);
    LCD_REG_1 = (LCD_REG_1 & 0xfffffc00) | (0xdd);

    LCD_REG_2 |= (1 << 5);
    LCD_REG_2 |= (1 << 6);
    LCD_REG_2 = (LCD_REG_2 & 0xfffffcff) | (0x2 << 8);

    LCD_REG_7 &= (0xf800ffff);
    LCD_REG_7 &= (0xfffff800);

    LCD_REG_8 = (LCD_REG_8 & (0xf800ffff)) | (0xb0 << 16);
    LCD_REG_8 = (LCD_REG_8 & (0xfffff800)) | (0xde); /* X-Y Geometry? */

    LCD_REG_5 |= 0xc;
    LCD_REG_5 = (LCD_REG_5 & ~(0x70)) | (0x3 << 4);
    LCD_REG_5 |= 2;

    LCD_REG_6 &= ~(1 << 15);
    LCD_REG_6 |= (0xe00);
    LCD_REG_6 = (LCD_REG_6 & (0xffffff1f)) | (0x4 << 5);
    LCD_REG_6 |= (1 << 4);

    LCD_REG_5 &= ~(1 << 7);
    LCD_FB_BASE_REG = phys_fb_address((unsigned long)lcd_driver_framebuffer);

    udelay(100000);

/* LCD init */
    outl((inl(0x70000080) & ~(1 << 28)), 0x70000080);
    udelay(10000);
    outl((inl(0x70000080) | (1 << 28)), 0x70000080);
    udelay(10000);

    lcd_write_reg(16, 0x4444);
    lcd_write_reg(17, 0x0001);
    lcd_write_reg(18, 0x0003);
    lcd_write_reg(19, 0x1119);
    lcd_write_reg(18, 0x0013);
    udelay(50000);

    lcd_write_reg(16, 0x4440);
    lcd_write_reg(19, 0x3119);
    udelay(150000);

    lcd_write_reg(1, 0x101b);
    lcd_write_reg(2, 0x0700);
    lcd_write_reg(3, 0x6020);
    lcd_write_reg(4, 0x0000);
    lcd_write_reg(5, 0x0000);
    lcd_write_reg(8, 0x0102);
    lcd_write_reg(9, 0x0000);
    lcd_write_reg(11, 0x4400);
    lcd_write_reg(12, 0x0110);

    lcd_write_reg(64, 0x0000);
    lcd_write_reg(65, 0x0000);
    lcd_write_reg(66, (219 << 8)); /* Screen resolution? */
    lcd_write_reg(67, 0x0000);
    lcd_write_reg(68, (175 << 8));
    lcd_write_reg(69, (219 << 8));

    lcd_write_reg(48, 0x0000);
    lcd_write_reg(49, 0x0704);
    lcd_write_reg(50, 0x0107);
    lcd_write_reg(51, 0x0704);
    lcd_write_reg(52, 0x0107);
    lcd_write_reg(53, 0x0002);
    lcd_write_reg(54, 0x0707);
    lcd_write_reg(55, 0x0503);
    lcd_write_reg(56, 0x0000);
    lcd_write_reg(57, 0x0000);

    lcd_write_reg(33, 175);

    lcd_write_reg(12, 0x0110);

    lcd_write_reg(16, 0x4740);

    lcd_write_reg(7, 0x0045);

    udelay(50000);

    lcd_write_reg(7, 0x0065);
    lcd_write_reg(7, 0x0067);

    udelay(50000);

    lcd_write_reg(7, 0x0077);
    lcd_send_msg(0x70, 34);
}

inline void lcd_update_rect(int x, int y, int width, int height)
{
    (void)x;
    (void)width;
    /* Turn off DMA and wait for the transfer to complete */
    /* TODO: Work out the proper delay */
    LCD_REG_6 &= ~1;
    udelay(1000);

    /* Copy the Rockbox framebuffer to the second framebuffer */
    /* TODO: Move the second framebuffer into uncached SDRAM */
    memcpy(((char*)&lcd_driver_framebuffer)+(y * sizeof(fb_data) * LCD_WIDTH),
           ((char *)&lcd_framebuffer)+(y * sizeof(fb_data) * LCD_WIDTH),
           ((height * sizeof(fb_data) * LCD_WIDTH)));
    cache_flush();

    /* Restart DMA */
    LCD_REG_6 |= 1;
}

inline void lcd_update(void)
{
    /* TODO: It may be faster to swap the addresses of lcd_driver_framebuffer
     * and lcd_framebuffer */
    /* Turn off DMA and wait for the transfer to complete */
    LCD_REG_6 &= ~1;
    udelay(1000);

    /* Copy the Rockbox framebuffer to the second framebuffer */
    memcpy(lcd_driver_framebuffer, lcd_framebuffer, sizeof(fb_data) * LCD_WIDTH * LCD_HEIGHT);
    cache_flush();

    /* Restart DMA */
    LCD_REG_6 |= 1;
}


/*** hardware configuration ***/

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

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

/* turn the display upside down (call lcd_update() afterwards) */
void lcd_set_flip(bool yesno)
{
    /* TODO: Implement lcd_set_flip() */
    (void)yesno;
}

/* Blitting functions */

void lcd_blit(const fb_data* data, int x, int by, int width,
              int bheight, int stride)
{
    /* TODO: Implement lcd_blit() */
    (void)data;
    (void)x;
    (void)by;
    (void)width;
    (void)bheight;
    (void)stride;
}

#define CSUB_X 2
#define CSUB_Y 2

#define RYFAC (31*257)
#define GYFAC (63*257)
#define BYFAC (31*257)
#define RVFAC 11170     /* 31 * 257 *  1.402    */
#define GVFAC (-11563)  /* 63 * 257 * -0.714136 */
#define GUFAC (-5572)   /* 63 * 257 * -0.344136 */
#define BUFAC 14118     /* 31 * 257 *  1.772    */

#define ROUNDOFFS (127*257)

/* Performance function to blit a YUV bitmap directly to the LCD
   Actually this code is from gigabeat, because this target is also
   writing direct to a buffer. */
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)
{
    const unsigned char *usrc;
    const unsigned char *vsrc;
    const unsigned char *ysrc;
    int xphase;
    int rc, gc, bc;
    int y, u, v;
    int red, green, blue;
    unsigned rbits, gbits, bbits;
    int count;
    fb_data *dst_row;


    width = (width + 1) & ~1;
    fb_data *dst = (fb_data*)lcd_driver_framebuffer + 
                   _x * LCD_WIDTH + (LCD_WIDTH - _y) - 1;
    fb_data *dst_last = dst - (height - 1);

    do
    {
        dst_row = dst;
        count = width;
        ysrc = src[0] + stride * src_y + src_x;

        /* upsampling, YUV->RGB conversion and reduction to RGB565 in one go */
        usrc = src[1] + (stride/CSUB_X) * (src_y/CSUB_Y)
                                           + (src_x/CSUB_X);
        vsrc = src[2] + (stride/CSUB_X) * (src_y/CSUB_Y)
                                           + (src_x/CSUB_X);
        xphase = src_x % CSUB_X;

        u = *usrc++ - 128;
        v = *vsrc++ - 128;
        rc = RVFAC * v + ROUNDOFFS;
        gc = GVFAC * v + GUFAC * u + ROUNDOFFS;
        bc = BUFAC * u + ROUNDOFFS;

        do
        {
            y = *ysrc++;
            red   = RYFAC * y + rc;
            green = GYFAC * y + gc;
            blue  = BYFAC * y + bc;

            if ((unsigned)red > (RYFAC*255+ROUNDOFFS))
            {
                if (red < 0)
                    red = 0;
                else
                    red = (RYFAC*255+ROUNDOFFS);
            }
            if ((unsigned)green > (GYFAC*255+ROUNDOFFS))
            {
                if (green < 0)
                    green = 0;
                else
                    green = (GYFAC*255+ROUNDOFFS);
            }
            if ((unsigned)blue > (BYFAC*255+ROUNDOFFS))
            {
                if (blue < 0)
                    blue = 0;
                else
                    blue = (BYFAC*255+ROUNDOFFS);
            }
            rbits = ((unsigned)red) >> 16 ;
            gbits = ((unsigned)green) >> 16 ;
            bbits = ((unsigned)blue) >> 16 ;

            *dst_row = (rbits << 11) | (gbits << 5) | bbits;

            /* next pixel - since rotated, add WIDTH */
            dst_row += LCD_WIDTH;

            if (++xphase >= CSUB_X)
            {
                u = *usrc++ - 128;
                v = *vsrc++ - 128;
                rc = RVFAC * v + ROUNDOFFS;
                gc = GVFAC * v + GUFAC * u + ROUNDOFFS;
                bc = BUFAC * u + ROUNDOFFS;
                xphase = 0;
            }
        }
        while (--count);

        if (dst == dst_last) break;

        dst--;
        src_y++;
    } while( 1);
}