/**

 * $Id: pvr2.c,v 1.9 2005-12-25 08:24:07 nkeynes Exp $

 *

 * PVR2 (Video) MMIO and supporting functions.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * 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 program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include "dream.h"

#include "video.h"

#include "mem.h"

#include "asic.h"

#include "modules.h"

#include "pvr2.h"

#define MMIO_IMPL

#include "pvr2.h"

char *video_base;

void pvr2_init( void );

uint32_t pvr2_run_slice( uint32_t );

void pvr2_next_frame( void );

struct dreamcast_module pvr2_module = { "PVR2", pvr2_init, NULL, NULL, 

					pvr2_run_slice, NULL,

					NULL, NULL };

void pvr2_init( void )

{

    register_io_region( &mmio_region_PVR2 );

    video_base = mem_get_region_by_name( MEM_REGION_VIDEO );

}

uint32_t pvr2_time_counter = 0;

uint32_t pvr2_time_per_frame = 20000000;

uint32_t pvr2_run_slice( uint32_t nanosecs ) 

{

    pvr2_time_counter += nanosecs;

    while( pvr2_time_counter >= pvr2_time_per_frame ) {

	pvr2_next_frame();

	pvr2_time_counter -= pvr2_time_per_frame;

    }

    return nanosecs;

}

uint32_t vid_stride, vid_lpf, vid_ppl, vid_hres, vid_vres, vid_col;

int interlaced, bChanged = 1, bEnabled = 0, vid_size = 0;

char *frame_start; /* current video start address (in real memory) */

/*

 * Display the next frame, copying the current contents of video ram to

 * the window. If the video configuration has changed, first recompute the

 * new frame size/depth.

 */

void pvr2_next_frame( void )

{

    if( bChanged ) {

        int dispsize = MMIO_READ( PVR2, DISPSIZE );

        int dispmode = MMIO_READ( PVR2, DISPMODE );

        int vidcfg = MMIO_READ( PVR2, VIDCFG );

        vid_stride = ((dispsize & DISPSIZE_MODULO) >> 20) - 1;

        vid_lpf = ((dispsize & DISPSIZE_LPF) >> 10) + 1;

        vid_ppl = ((dispsize & DISPSIZE_PPL)) + 1;

        vid_col = (dispmode & DISPMODE_COL);

        frame_start = video_base + MMIO_READ( PVR2, DISPADDR1 );

        interlaced = (vidcfg & VIDCFG_I ? 1 : 0);

        bEnabled = (dispmode & DISPMODE_DE) && (vidcfg & VIDCFG_VO ) ? 1 : 0;

        vid_size = (vid_ppl * vid_lpf) << (interlaced ? 3 : 2);

        vid_hres = vid_ppl;

        vid_vres = vid_lpf;

        if( interlaced ) vid_vres <<= 1;

        switch( vid_col ) {

            case MODE_RGB15:

            case MODE_RGB16: vid_hres <<= 1; break;

            case MODE_RGB24: vid_hres *= 3; break;

            case MODE_RGB32: vid_hres <<= 2; break;

        }

        vid_hres >>= 2;

        video_update_size( vid_hres, vid_vres, vid_col );

        bChanged = 0;

    }

    if( bEnabled ) {

        /* Assume bit depths match for now... */

        memcpy( video_data, frame_start, vid_size );

    } else {

        memset( video_data, 0, vid_size );

    }

    video_update_frame();

    asic_event( EVENT_SCANLINE1 );

    asic_event( EVENT_SCANLINE2 );

    asic_event( EVENT_RETRACE );

}

void mmio_region_PVR2_write( uint32_t reg, uint32_t val )

{

    if( reg >= 0x200 && reg < 0x600 ) { /* Fog table */

        MMIO_WRITE( PVR2, reg, val );

        /* I don't want to hear about these */

        return;

    }

    INFO( "PVR2 write to %08X <= %08X [%s: %s]", reg, val, 

          MMIO_REGID(PVR2,reg), MMIO_REGDESC(PVR2,reg) );

    switch(reg) {

        case DISPSIZE: bChanged = 1;

        case DISPMODE: bChanged = 1;

        case DISPADDR1: bChanged = 1;

        case DISPADDR2: bChanged = 1;

        case VIDCFG: bChanged = 1;

            break;

    }

    MMIO_WRITE( PVR2, reg, val );

}

MMIO_REGION_READ_FN( PVR2, reg )

{

    switch( reg ) {

        case BEAMPOS:

            return sh4r.icount&0x20 ? 0x2000 : 1;

        default:

            return MMIO_READ( PVR2, reg );

    }

}

void pvr2_set_base_address( uint32_t base ) 

{

    mmio_region_PVR2_write( DISPADDR1, base );

}