/**

 * $Id$

 *

 * PVR2 (Video) Core module implementation and MMIO registers.

 *

 * 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.

 */

#define MODULE pvr2_module

#include <assert.h>

#include "dream.h"

#include "eventq.h"

#include "display.h"

#include "mem.h"

#include "asic.h"

#include "clock.h"

#include "pvr2/pvr2.h"

#include "pvr2/pvr2mmio.h"

#include "pvr2/scene.h"

#include "sh4/sh4.h"

#define MMIO_IMPL

#include "pvr2/pvr2mmio.h"

unsigned char *video_base;

#define MAX_RENDER_BUFFERS 4

#define HPOS_PER_FRAME 0

#define HPOS_PER_LINECOUNT 1

static void pvr2_init( void );

static void pvr2_reset( void );

static uint32_t pvr2_run_slice( uint32_t );

static void pvr2_save_state( FILE *f );

static int pvr2_load_state( FILE *f );

static void pvr2_update_raster_posn( uint32_t nanosecs );

static void pvr2_schedule_scanline_event( int eventid, int line, int minimum_lines, int line_time_ns );

static render_buffer_t pvr2_get_render_buffer( frame_buffer_t frame );

static render_buffer_t pvr2_next_render_buffer( );

static render_buffer_t pvr2_frame_buffer_to_render_buffer( frame_buffer_t frame );

uint32_t pvr2_get_sync_status();

void pvr2_display_frame( void );

static int output_colour_formats[] = { COLFMT_BGRA1555, COLFMT_RGB565, COLFMT_BGR888, COLFMT_BGRA8888 };

struct dreamcast_module pvr2_module = { "PVR2", pvr2_init, pvr2_reset, NULL, 

					pvr2_run_slice, NULL,

					pvr2_save_state, pvr2_load_state };

display_driver_t display_driver = NULL;

struct pvr2_state {

    uint32_t frame_count;

    uint32_t line_count;

    uint32_t line_remainder;

    uint32_t cycles_run; /* Cycles already executed prior to main time slice */

    uint32_t irq_hpos_line;

    uint32_t irq_hpos_line_count;

    uint32_t irq_hpos_mode;

    uint32_t irq_hpos_time_ns; /* Time within the line */

    uint32_t irq_vpos1;

    uint32_t irq_vpos2;

    uint32_t odd_even_field; /* 1 = odd, 0 = even */

    int32_t palette_changed; /* TRUE if palette has changed since last render */

    uint32_t padding; /* FIXME: Remove in next DST version */

    /* timing */

    uint32_t dot_clock;

    uint32_t total_lines;

    uint32_t line_size;

    uint32_t line_time_ns;

    uint32_t vsync_lines;

    uint32_t hsync_width_ns;

    uint32_t front_porch_ns;

    uint32_t back_porch_ns;

    uint32_t retrace_start_line;

    uint32_t retrace_end_line;

    int32_t interlaced;

} pvr2_state;

static gchar *save_next_render_filename;

static render_buffer_t render_buffers[MAX_RENDER_BUFFERS];

static uint32_t render_buffer_count = 0;

static render_buffer_t displayed_render_buffer = NULL;

static uint32_t displayed_border_colour = 0;

/**

 * Event handler for the hpos callback

 */

static void pvr2_hpos_callback( int eventid ) {

    asic_event( eventid );

    pvr2_update_raster_posn(sh4r.slice_cycle);

    if( pvr2_state.irq_hpos_mode == HPOS_PER_LINECOUNT ) {

	pvr2_state.irq_hpos_line += pvr2_state.irq_hpos_line_count;

	while( pvr2_state.irq_hpos_line > (pvr2_state.total_lines>>1) ) {

	    pvr2_state.irq_hpos_line -= (pvr2_state.total_lines>>1);

	}

    }

    pvr2_schedule_scanline_event( eventid, pvr2_state.irq_hpos_line, 1, 

				  pvr2_state.irq_hpos_time_ns );

}

/**

 * Event handler for the scanline callbacks. Fires the corresponding

 * ASIC event, and resets the timer for the next field.

 */

static void pvr2_scanline_callback( int eventid ) {

    asic_event( eventid );

    pvr2_update_raster_posn(sh4r.slice_cycle);

    if( eventid == EVENT_SCANLINE1 ) {

	pvr2_schedule_scanline_event( eventid, pvr2_state.irq_vpos1, 1, 0 );

    } else {

	pvr2_schedule_scanline_event( eventid, pvr2_state.irq_vpos2, 1, 0 );

    }

}

static void pvr2_init( void )

{

    int i;

    register_io_region( &mmio_region_PVR2 );

    register_io_region( &mmio_region_PVR2PAL );

    register_io_region( &mmio_region_PVR2TA );

    register_event_callback( EVENT_HPOS, pvr2_hpos_callback );

    register_event_callback( EVENT_SCANLINE1, pvr2_scanline_callback );

    register_event_callback( EVENT_SCANLINE2, pvr2_scanline_callback );

    video_base = mem_get_region_by_name( MEM_REGION_VIDEO );

    texcache_init();

    pvr2_reset();

    pvr2_ta_reset();

    save_next_render_filename = NULL;

    for( i=0; i<MAX_RENDER_BUFFERS; i++ ) {

	render_buffers[i] = NULL;

    }

    render_buffer_count = 0;

    displayed_render_buffer = NULL;

    displayed_border_colour = 0;

}

static void pvr2_reset( void )

{

    int i;

    pvr2_state.line_count = 0;

    pvr2_state.line_remainder = 0;

    pvr2_state.cycles_run = 0;

    pvr2_state.irq_vpos1 = 0;

    pvr2_state.irq_vpos2 = 0;

    pvr2_state.dot_clock = PVR2_DOT_CLOCK;

    pvr2_state.back_porch_ns = 4000;

    pvr2_state.palette_changed = FALSE;

    mmio_region_PVR2_write( DISP_TOTAL, 0x0270035F );

    mmio_region_PVR2_write( DISP_SYNCTIME, 0x07D6A53F );

    mmio_region_PVR2_write( YUV_ADDR, 0 );

    mmio_region_PVR2_write( YUV_CFG, 0 );

    pvr2_ta_init();

    texcache_flush();

    if( display_driver ) {

	display_driver->display_blank(0);

	for( i=0; i<render_buffer_count; i++ ) {

	    display_driver->destroy_render_buffer(render_buffers[i]);

	    render_buffers[i] = NULL;

	}

	render_buffer_count = 0;

    }

}

void pvr2_save_render_buffer( FILE *f, render_buffer_t buffer )

{

    struct frame_buffer fbuf;

    fbuf.width = buffer->width;

    fbuf.height = buffer->height;

    fbuf.rowstride = fbuf.width*3;

    fbuf.colour_format = COLFMT_BGR888;

    fbuf.inverted = buffer->inverted;

    fbuf.data = g_malloc0( buffer->width * buffer->height * 3 );

    display_driver->read_render_buffer( fbuf.data, buffer, fbuf.rowstride, COLFMT_BGR888 );

    write_png_to_stream( f, &fbuf );

    g_free( fbuf.data );

    fwrite( &buffer->rowstride, sizeof(buffer->rowstride), 1, f );

    fwrite( &buffer->colour_format, sizeof(buffer->colour_format), 1, f );

    fwrite( &buffer->address, sizeof(buffer->address), 1, f );

    fwrite( &buffer->scale, sizeof(buffer->scale), 1, f );

    int32_t flushed = (int32_t)buffer->flushed; // Force to 32-bits for save-file consistency

    fwrite( &flushed, sizeof(flushed), 1, f );

}

render_buffer_t pvr2_load_render_buffer( FILE *f )

{

    frame_buffer_t frame = read_png_from_stream( f );

    if( frame == NULL ) {

	return NULL;

    }

    render_buffer_t buffer = pvr2_frame_buffer_to_render_buffer(frame);

    if( buffer != NULL ) {

        int32_t flushed;

	fread( &buffer->rowstride, sizeof(buffer->rowstride), 1, f );

	fread( &buffer->colour_format, sizeof(buffer->colour_format), 1, f );

	fread( &buffer->address, sizeof(buffer->address), 1, f );

	fread( &buffer->scale, sizeof(buffer->scale), 1, f );

	fread( &flushed, sizeof(flushed), 1, f );

	buffer->flushed = (gboolean)flushed;

    } else {

	fseek( f, sizeof(buffer->rowstride)+sizeof(buffer->colour_format)+

	       sizeof(buffer->address)+sizeof(buffer->scale)+

	       sizeof(int32_t), SEEK_CUR );

    }

    return buffer;

}

void pvr2_save_render_buffers( FILE *f )

{

    int i;

    uint32_t has_frontbuffer;

    fwrite( &render_buffer_count, sizeof(render_buffer_count), 1, f );

    if( displayed_render_buffer != NULL ) {

	has_frontbuffer = 1;

	fwrite( &has_frontbuffer, sizeof(has_frontbuffer), 1, f );

	pvr2_save_render_buffer( f, displayed_render_buffer );

    } else {

	has_frontbuffer = 0;

	fwrite( &has_frontbuffer, sizeof(has_frontbuffer), 1, f );

    }

    for( i=0; i<render_buffer_count; i++ ) {

	if( render_buffers[i] != displayed_render_buffer && render_buffers[i] != NULL ) {

	    pvr2_save_render_buffer( f, render_buffers[i] );

	}

    }

}

gboolean pvr2_load_render_buffers( FILE *f )

{

    uint32_t count, has_frontbuffer;

    int i;

    fread( &count, sizeof(count), 1, f );

    if( count > MAX_RENDER_BUFFERS ) {

	return FALSE;

    }

    fread( &has_frontbuffer, sizeof(has_frontbuffer), 1, f );

    for( i=0; i<render_buffer_count; i++ ) {

	display_driver->destroy_render_buffer(render_buffers[i]);

	render_buffers[i] = NULL;

    }

    render_buffer_count = 0;

    if( has_frontbuffer ) {

	displayed_render_buffer = pvr2_load_render_buffer(f);

	display_driver->display_render_buffer( displayed_render_buffer );

	count--;

    }

    for( i=0; i<count; i++ ) {

	pvr2_load_render_buffer( f );

    }

    return TRUE;

}

static void pvr2_save_state( FILE *f )

{

    pvr2_save_render_buffers( f );

    fwrite( &pvr2_state, sizeof(pvr2_state), 1, f );

    pvr2_ta_save_state( f );

    pvr2_yuv_save_state( f );

}

static int pvr2_load_state( FILE *f )

{

    if( !pvr2_load_render_buffers(f) )

	return 1;

    if( fread( &pvr2_state, sizeof(pvr2_state), 1, f ) != 1 )

	return 1;

    if( pvr2_ta_load_state(f) ) {

	return 1;

    }

    return pvr2_yuv_load_state(f);

}

/**

 * Update the current raster position to the given number of nanoseconds,

 * relative to the last time slice. (ie the raster will be adjusted forward

 * by nanosecs - nanosecs_already_run_this_timeslice)

 */

static void pvr2_update_raster_posn( uint32_t nanosecs )

{

    uint32_t old_line_count = pvr2_state.line_count;

    if( pvr2_state.line_time_ns == 0 ) {

	return; /* do nothing */

    }

    pvr2_state.line_remainder += (nanosecs - pvr2_state.cycles_run);

    pvr2_state.cycles_run = nanosecs;

    while( pvr2_state.line_remainder >= pvr2_state.line_time_ns ) {

	pvr2_state.line_count ++;

	pvr2_state.line_remainder -= pvr2_state.line_time_ns;

    }

    if( pvr2_state.line_count >= pvr2_state.total_lines ) {

	pvr2_state.line_count -= pvr2_state.total_lines;

	if( pvr2_state.interlaced ) {

	    pvr2_state.odd_even_field = !pvr2_state.odd_even_field;

	}

    }

    if( pvr2_state.line_count >= pvr2_state.retrace_end_line &&

	(old_line_count < pvr2_state.retrace_end_line ||

	 old_line_count > pvr2_state.line_count) ) {

	pvr2_state.frame_count++;

	pvr2_display_frame();

    }

}

static uint32_t pvr2_run_slice( uint32_t nanosecs ) 

{

    pvr2_update_raster_posn( nanosecs );

    pvr2_state.cycles_run = 0;

    return nanosecs;

}

int pvr2_get_frame_count() 

{

    return pvr2_state.frame_count;

}

void pvr2_redraw_display()

{

    if( display_driver != NULL ) {

        if( displayed_render_buffer == NULL ) {

            display_driver->display_blank(displayed_border_colour);

        } else {

            display_driver->display_render_buffer(displayed_render_buffer);

        }

    }

}

gboolean pvr2_save_next_scene( const gchar *filename )

{

    if( save_next_render_filename != NULL ) {

	g_free( save_next_render_filename );

    } 

    save_next_render_filename = g_strdup(filename);

    return TRUE;

}

/**

 * 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_display_frame( void )

{

    int dispmode = MMIO_READ( PVR2, DISP_MODE );

    int vidcfg = MMIO_READ( PVR2, DISP_SYNCCFG );

    gboolean bEnabled = (dispmode & DISPMODE_ENABLE) && (vidcfg & DISPCFG_VO ) ? TRUE : FALSE;

    if( display_driver == NULL ) {

	return; /* can't really do anything much */

    } else if( !bEnabled ) {

	/* Output disabled == black */

	displayed_render_buffer = NULL;

	displayed_border_colour = 0;

	display_driver->display_blank( 0 ); 

    } else if( MMIO_READ( PVR2, DISP_CFG2 ) & 0x08 ) { 

	/* Enabled but blanked - border colour */

	displayed_border_colour = MMIO_READ( PVR2, DISP_BORDER );

	displayed_render_buffer = NULL;

	display_driver->display_blank( displayed_border_colour );

    } else {

	/* Real output - determine dimensions etc */

	struct frame_buffer fbuf;

	uint32_t dispsize = MMIO_READ( PVR2, DISP_SIZE );

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

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

	fbuf.colour_format = output_colour_formats[(dispmode & DISPMODE_COLFMT) >> 2];

	fbuf.width = vid_ppl << 2 / colour_formats[fbuf.colour_format].bpp;

	fbuf.height = ((dispsize & DISPSIZE_LPF) >> 10) + 1;

	fbuf.size = vid_ppl << 2 * fbuf.height;

	fbuf.rowstride = (vid_ppl + vid_stride) << 2;

	/* Determine the field to display, and deinterlace if possible */

	if( pvr2_state.interlaced ) {

	    if( vid_ppl == vid_stride ) { /* Magic deinterlace */

		fbuf.height = fbuf.height << 1;

		fbuf.rowstride = vid_ppl << 2;

		fbuf.address = MMIO_READ( PVR2, DISP_ADDR1 );

	    } else { 

		/* Just display the field as is, folks. This is slightly tricky -

		 * we pick the field based on which frame is about to come through,

		 * which may not be the same as the odd_even_field.

		 */

		gboolean oddfield = pvr2_state.odd_even_field;

		if( pvr2_state.line_count >= pvr2_state.retrace_start_line ) {

		    oddfield = !oddfield;

		}

		if( oddfield ) {

		    fbuf.address = MMIO_READ( PVR2, DISP_ADDR1 );

		} else {

		    fbuf.address = MMIO_READ( PVR2, DISP_ADDR2 );

		}

	    }

	} else {

	    fbuf.address = MMIO_READ( PVR2, DISP_ADDR1 );

	}

	fbuf.address = (fbuf.address & 0x00FFFFFF) + PVR2_RAM_BASE;

	fbuf.inverted = FALSE;

	fbuf.data = video_base + (fbuf.address&0x00FFFFFF);

	render_buffer_t rbuf = pvr2_get_render_buffer( &fbuf );

	if( rbuf == NULL ) {

	    rbuf = pvr2_frame_buffer_to_render_buffer( &fbuf );

	}

	displayed_render_buffer = rbuf;

	if( rbuf != NULL ) {

	    display_driver->display_render_buffer( rbuf );

	}

    }

}

/**

 * This has to handle every single register individually as they all get masked 

 * off differently (and its easier to do it at write time)

 */

void mmio_region_PVR2_write( uint32_t reg, uint32_t val )

{

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

        MMIO_WRITE( PVR2, reg, val );

        return;

    }

    switch(reg) {

    case PVRID:

    case PVRVER:

    case GUNPOS: /* Read only registers */

	break;

    case PVRRESET:

	val &= 0x00000007; /* Do stuff? */

	MMIO_WRITE( PVR2, reg, val );

	break;

    case RENDER_START: /* Don't really care what value */

	if( save_next_render_filename != NULL ) {

	    if( pvr2_render_save_scene(save_next_render_filename) == 0 ) {

		INFO( "Saved scene to %s", save_next_render_filename);

	    }

	    g_free( save_next_render_filename );

	    save_next_render_filename = NULL;

	}

	pvr2_scene_read();

	render_buffer_t buffer = pvr2_next_render_buffer();

	if( buffer != NULL ) {

	    pvr2_scene_render( buffer );

	}

	asic_event( EVENT_PVR_RENDER_DONE );

	break;

    case RENDER_POLYBASE:

    	MMIO_WRITE( PVR2, reg, val&0x00F00000 );

    	break;

    case RENDER_TSPCFG:

    	MMIO_WRITE( PVR2, reg, val&0x00010101 );

    	break;

    case DISP_BORDER:

    	MMIO_WRITE( PVR2, reg, val&0x01FFFFFF );

    	break;

    case DISP_MODE:

    	MMIO_WRITE( PVR2, reg, val&0x00FFFF7F );

    	break;

    case RENDER_MODE:

    	MMIO_WRITE( PVR2, reg, val&0x00FFFF0F );

    	break;

    case RENDER_SIZE:

    	MMIO_WRITE( PVR2, reg, val&0x000001FF );

    	break;

    case DISP_ADDR1:

	val &= 0x00FFFFFC;

	MMIO_WRITE( PVR2, reg, val );

	pvr2_update_raster_posn(sh4r.slice_cycle);

	break;

    case DISP_ADDR2:

    	MMIO_WRITE( PVR2, reg, val&0x00FFFFFC );

	pvr2_update_raster_posn(sh4r.slice_cycle);

    	break;

    case DISP_SIZE:

    	MMIO_WRITE( PVR2, reg, val&0x3FFFFFFF );

    	break;

    case RENDER_ADDR1:

    case RENDER_ADDR2:

    	MMIO_WRITE( PVR2, reg, val&0x01FFFFFC );

    	break;

    case RENDER_HCLIP:

	MMIO_WRITE( PVR2, reg, val&0x07FF07FF );

	break;

    case RENDER_VCLIP:

	MMIO_WRITE( PVR2, reg, val&0x03FF03FF );

	break;

    case DISP_HPOSIRQ:

	MMIO_WRITE( PVR2, reg, val&0x03FF33FF );

	pvr2_state.irq_hpos_line = val & 0x03FF;

	pvr2_state.irq_hpos_time_ns = 2000000*((val>>16)&0x03FF)/pvr2_state.dot_clock;

	pvr2_state.irq_hpos_mode = (val >> 12) & 0x03;

	switch( pvr2_state.irq_hpos_mode ) {

	case 3: /* Reserved - treat as 0 */

	case 0: /* Once per frame at specified line */

	    pvr2_state.irq_hpos_mode = HPOS_PER_FRAME;

	    break;

	case 2: /* Once per line - as per-line-count */

	    pvr2_state.irq_hpos_line = 1;

	    pvr2_state.irq_hpos_mode = 1;

	case 1: /* Once per N lines */

	    pvr2_state.irq_hpos_line_count = pvr2_state.irq_hpos_line;

	    pvr2_state.irq_hpos_line = (pvr2_state.line_count >> 1) + 

		pvr2_state.irq_hpos_line_count;

	    while( pvr2_state.irq_hpos_line > (pvr2_state.total_lines>>1) ) {

		pvr2_state.irq_hpos_line -= (pvr2_state.total_lines>>1);

	    }

	    pvr2_state.irq_hpos_mode = HPOS_PER_LINECOUNT;

	}

	pvr2_schedule_scanline_event( EVENT_HPOS, pvr2_state.irq_hpos_line, 0,

					  pvr2_state.irq_hpos_time_ns );

	break;

    case DISP_VPOSIRQ:

	val = val & 0x03FF03FF;

	pvr2_state.irq_vpos1 = (val >> 16);

	pvr2_state.irq_vpos2 = val & 0x03FF;

	pvr2_update_raster_posn(sh4r.slice_cycle);

	pvr2_schedule_scanline_event( EVENT_SCANLINE1, pvr2_state.irq_vpos1, 0, 0 );

	pvr2_schedule_scanline_event( EVENT_SCANLINE2, pvr2_state.irq_vpos2, 0, 0 );

	MMIO_WRITE( PVR2, reg, val );

	break;

    case RENDER_NEARCLIP:

	MMIO_WRITE( PVR2, reg, val & 0x7FFFFFFF );

	break;

    case RENDER_SHADOW:

	MMIO_WRITE( PVR2, reg, val&0x000001FF );

	break;

    case RENDER_OBJCFG:

    	MMIO_WRITE( PVR2, reg, val&0x003FFFFF );

    	break;

    case RENDER_TSPCLIP:

    	MMIO_WRITE( PVR2, reg, val&0x7FFFFFFF );

    	break;

    case RENDER_FARCLIP:

	MMIO_WRITE( PVR2, reg, val&0xFFFFFFF0 );

	break;

    case RENDER_BGPLANE:

    	MMIO_WRITE( PVR2, reg, val&0x1FFFFFFF );

    	break;

    case RENDER_ISPCFG:

    	MMIO_WRITE( PVR2, reg, val&0x00FFFFF9 );

    	break;

    case VRAM_CFG1:

	MMIO_WRITE( PVR2, reg, val&0x000000FF );

	break;

    case VRAM_CFG2:

	MMIO_WRITE( PVR2, reg, val&0x003FFFFF );

	break;

    case VRAM_CFG3:

	MMIO_WRITE( PVR2, reg, val&0x1FFFFFFF );

	break;

    case RENDER_FOGTBLCOL:

    case RENDER_FOGVRTCOL:

	MMIO_WRITE( PVR2, reg, val&0x00FFFFFF );

	break;

    case RENDER_FOGCOEFF:

	MMIO_WRITE( PVR2, reg, val&0x0000FFFF );

	break;

    case RENDER_CLAMPHI:

    case RENDER_CLAMPLO:

	MMIO_WRITE( PVR2, reg, val );

	break;

    case RENDER_TEXSIZE:

	MMIO_WRITE( PVR2, reg, val&0x00031F1F );

	break;

    case RENDER_PALETTE:

	MMIO_WRITE( PVR2, reg, val&0x00000003 );

	break;

    case RENDER_ALPHA_REF:

	MMIO_WRITE( PVR2, reg, val&0x000000FF );

	break;

	/********** CRTC registers *************/

    case DISP_HBORDER:

    case DISP_VBORDER:

	MMIO_WRITE( PVR2, reg, val&0x03FF03FF );

	break;

    case DISP_TOTAL:

	val = val & 0x03FF03FF;

	MMIO_WRITE( PVR2, reg, val );

	pvr2_update_raster_posn(sh4r.slice_cycle);

	pvr2_state.total_lines = (val >> 16) + 1;

	pvr2_state.line_size = (val & 0x03FF) + 1;

	pvr2_state.line_time_ns = 1000000 * pvr2_state.line_size / pvr2_state.dot_clock;

	pvr2_state.retrace_end_line = 0x2A;

	pvr2_state.retrace_start_line = pvr2_state.total_lines - 6;

	pvr2_schedule_scanline_event( EVENT_SCANLINE1, pvr2_state.irq_vpos1, 0, 0 );

	pvr2_schedule_scanline_event( EVENT_SCANLINE2, pvr2_state.irq_vpos2, 0, 0 );

	pvr2_schedule_scanline_event( EVENT_HPOS, pvr2_state.irq_hpos_line, 0, 

					  pvr2_state.irq_hpos_time_ns );

	break;

    case DISP_SYNCCFG:

	MMIO_WRITE( PVR2, reg, val&0x000003FF );

	pvr2_state.interlaced = (val & 0x0010) ? TRUE : FALSE;

	break;

    case DISP_SYNCTIME:

	pvr2_state.vsync_lines = (val >> 8) & 0x0F;

	pvr2_state.hsync_width_ns = ((val & 0x7F) + 1) * 2000000 / pvr2_state.dot_clock;

	MMIO_WRITE( PVR2, reg, val&0xFFFFFF7F );

	break;

    case DISP_CFG2:

	MMIO_WRITE( PVR2, reg, val&0x003F01FF );

	break;

    case DISP_HPOS:

	val = val & 0x03FF;

	pvr2_state.front_porch_ns = (val + 1) * 1000000 / pvr2_state.dot_clock;

	MMIO_WRITE( PVR2, reg, val );

	break;

    case DISP_VPOS:

	MMIO_WRITE( PVR2, reg, val&0x03FF03FF );

	break;

	/*********** Tile accelerator registers ***********/

    case TA_POLYPOS:

    case TA_LISTPOS:

	/* Readonly registers */

	break;

    case TA_TILEBASE:

    case TA_LISTEND:

    case TA_LISTBASE:

	MMIO_WRITE( PVR2, reg, val&0x00FFFFE0 );

	break;

    case RENDER_TILEBASE:

    case TA_POLYBASE:

    case TA_POLYEND:

	MMIO_WRITE( PVR2, reg, val&0x00FFFFFC );

	break;

    case TA_TILESIZE:

	MMIO_WRITE( PVR2, reg, val&0x000F003F );

	break;

    case TA_TILECFG:

	MMIO_WRITE( PVR2, reg, val&0x00133333 );

	break;

    case TA_INIT:

	if( val & 0x80000000 )

	    pvr2_ta_init();

	break;

    case TA_REINIT:

	break;

	/**************** Scaler registers? ****************/

    case RENDER_SCALER:

	MMIO_WRITE( PVR2, reg, val&0x0007FFFF );

	break;

    case YUV_ADDR:

	val = val & 0x00FFFFF8;

	MMIO_WRITE( PVR2, reg, val );

	pvr2_yuv_init( val );

	break;

    case YUV_CFG:

	MMIO_WRITE( PVR2, reg, val&0x01013F3F );

	pvr2_yuv_set_config(val);

	break;

	/**************** Unknowns ***************/

    case PVRUNK1:

    	MMIO_WRITE( PVR2, reg, val&0x000007FF );

    	break;

    case PVRUNK2:

	MMIO_WRITE( PVR2, reg, val&0x00000007 );

	break;

    case PVRUNK3:

	MMIO_WRITE( PVR2, reg, val&0x000FFF3F );

	break;

    case PVRUNK5:

	MMIO_WRITE( PVR2, reg, val&0x0000FFFF );

	break;

    case PVRUNK7:

	MMIO_WRITE( PVR2, reg, val&0x00000001 );

	break;

    }

}

/**

 * Calculate the current read value of the syncstat register, using

 * the current SH4 clock time as an offset from the last timeslice.

 * The register reads (LSB to MSB) as:

 *     0..9  Current scan line

 *     10    Odd/even field (1 = odd, 0 = even)

 *     11    Display active (including border and overscan)

 *     12    Horizontal sync off

 *     13    Vertical sync off

 * Note this method is probably incorrect for anything other than straight

 * interlaced PAL/NTSC, and needs further testing. 

 */

uint32_t pvr2_get_sync_status()

{

    pvr2_update_raster_posn(sh4r.slice_cycle);

    uint32_t result = pvr2_state.line_count;

    if( pvr2_state.odd_even_field ) {

	result |= 0x0400;

    }

    if( (pvr2_state.line_count & 0x01) == pvr2_state.odd_even_field ) {

	if( pvr2_state.line_remainder > pvr2_state.hsync_width_ns ) {

	    result |= 0x1000; /* !HSYNC */

	}

	if( pvr2_state.line_count >= pvr2_state.vsync_lines ) {

	    if( pvr2_state.line_remainder > pvr2_state.front_porch_ns ) {

		result |= 0x2800; /* Display active */

	    } else {

		result |= 0x2000; /* Front porch */

	    }

	}

    } else {

	if( pvr2_state.line_count >= pvr2_state.vsync_lines ) {

	    if( pvr2_state.line_remainder < (pvr2_state.line_time_ns - pvr2_state.back_porch_ns)) {

		result |= 0x3800; /* Display active */

	    } else {

		result |= 0x3000;

	    }

	} else {

	    result |= 0x1000; /* Back porch */

	}

    }

    return result;

}

/**

 * Schedule a "scanline" event. This actually goes off at

 * 2 * line in even fields and 2 * line + 1 in odd fields.

 * Otherwise this behaves as per pvr2_schedule_line_event().

 * The raster position should be updated before calling this

 * method.

 * @param eventid Event to fire at the specified time

 * @param line Line on which to fire the event (this is 2n/2n+1 for interlaced

 *  displays). 

 * @param hpos_ns Nanoseconds into the line at which to fire.

 */

static void pvr2_schedule_scanline_event( int eventid, int line, int minimum_lines, int hpos_ns )

{

    uint32_t field = pvr2_state.odd_even_field;

    if( line <= pvr2_state.line_count && pvr2_state.interlaced ) {

	field = !field;

    }

    if( hpos_ns > pvr2_state.line_time_ns ) {

	hpos_ns = pvr2_state.line_time_ns;

    }

    line <<= 1;

    if( field ) {

	line += 1;

    }

    if( line < pvr2_state.total_lines ) {

	uint32_t lines;

	uint32_t time;

	if( line <= pvr2_state.line_count ) {

	    lines = (pvr2_state.total_lines - pvr2_state.line_count + line);

	} else {

	    lines = (line - pvr2_state.line_count);

	}

	if( lines <= minimum_lines ) {

	    lines += pvr2_state.total_lines;

	}

	time = (lines * pvr2_state.line_time_ns) - pvr2_state.line_remainder + hpos_ns;

	event_schedule( eventid, time );

    } else {

	event_cancel( eventid );

    }

}

MMIO_REGION_READ_FN( PVR2, reg )

{

    switch( reg ) {

        case DISP_SYNCSTAT:

            return pvr2_get_sync_status();

        default:

            return MMIO_READ( PVR2, reg );

    }

}

MMIO_REGION_WRITE_FN( PVR2PAL, reg, val )

{

    MMIO_WRITE( PVR2PAL, reg, val );

    pvr2_state.palette_changed = TRUE;

}

void pvr2_check_palette_changed()

{

    if( pvr2_state.palette_changed ) {

	texcache_invalidate_palette();

	pvr2_state.palette_changed = FALSE;

    }

}

MMIO_REGION_READ_DEFFN( PVR2PAL );

void pvr2_set_base_address( uint32_t base ) 

{

    mmio_region_PVR2_write( DISP_ADDR1, base );

}

int32_t mmio_region_PVR2TA_read( uint32_t reg )

{

    return 0xFFFFFFFF;

}

void mmio_region_PVR2TA_write( uint32_t reg, uint32_t val )

{

    pvr2_ta_write( (unsigned char *)&val, sizeof(uint32_t) );

}

/**

 * Find the render buffer corresponding to the requested output frame

 * (does not consider texture renders). 

 * @return the render_buffer if found, or null if no such buffer.

 *

 * Note: Currently does not consider "partial matches", ie partial

 * frame overlap - it probably needs to do this.

 */

render_buffer_t pvr2_get_render_buffer( frame_buffer_t frame )

{

    int i;

    for( i=0; i<render_buffer_count; i++ ) {

	if( render_buffers[i] != NULL && render_buffers[i]->address == frame->address ) {

	    return render_buffers[i];

	}

    }

    return NULL;

}

/**

 * Allocate a render buffer with the requested parameters.

 * The order of preference is:

 *   1. An existing buffer with the same address. (not flushed unless the new

 * size is smaller than the old one).

 *   2. An existing buffer with the same size chosen by LRU order. Old buffer

 *       is flushed to vram.

 *   3. A new buffer if one can be created.

 *   4. The current display buff

 * Note: The current display field(s) will never be overwritten except as a last

 * resort.

 */

render_buffer_t pvr2_alloc_render_buffer( sh4addr_t render_addr, int width, int height )

{

    int i;

    render_buffer_t result = NULL;

    /* Check existing buffers for an available buffer */

    for( i=0; i<render_buffer_count; i++ ) {

	if( render_buffers[i]->width == width && render_buffers[i]->height == height ) {

	    /* needs to be the right dimensions */

	    if( render_buffers[i]->address == render_addr ) {

		if( displayed_render_buffer == render_buffers[i] ) {

		    /* Same address, but we can't use it because the

		     * display has it. Mark it as unaddressed for later.

		     */

		    render_buffers[i]->address = -1;

		} else {

		    /* perfect */

		    result = render_buffers[i];

		    break;

		}

	    } else if( render_buffers[i]->address == -1 && result == NULL && 

		       displayed_render_buffer != render_buffers[i] ) {

		result = render_buffers[i];

	    }

	} else if( render_buffers[i]->address == render_addr ) {

	    /* right address, wrong size - if it's larger, flush it, otherwise 

	     * nuke it quietly */

	    if( render_buffers[i]->width * render_buffers[i]->height >

		width*height ) {

		pvr2_render_buffer_copy_to_sh4( render_buffers[i] );

	    }

	    render_buffers[i]->address = -1;

	}

    }

    /* Nothing available - make one */

    if( result == NULL ) {

	if( render_buffer_count == MAX_RENDER_BUFFERS ) {

	    /* maximum buffers reached - need to throw one away */

	    uint32_t field1_addr = MMIO_READ( PVR2, DISP_ADDR1 );

	    uint32_t field2_addr = MMIO_READ( PVR2, DISP_ADDR2 );

	    for( i=0; i<render_buffer_count; i++ ) {

		if( render_buffers[i]->address != field1_addr &&

		    render_buffers[i]->address != field2_addr &&

		    render_buffers[i] != displayed_render_buffer ) {

		    /* Never throw away the current "front buffer(s)" */

		    result = render_buffers[i];

		    if( !result->flushed ) {

			pvr2_render_buffer_copy_to_sh4( result );

		    }

		    if( result->width != width || result->height != height ) {

			display_driver->destroy_render_buffer(render_buffers[i]);

			result = display_driver->create_render_buffer(width,height);

			render_buffers[i] = result;

		    }

		    break;

		}

	    }

	} else {

	    result = display_driver->create_render_buffer(width,height);

	    if( result != NULL ) { 

		render_buffers[render_buffer_count++] = result;

	    }

	}

    }

    if( result != NULL ) {

	result->address = render_addr;

    }

    return result;

}

/**

 * Allocate a render buffer based on the current rendering settings

 */

render_buffer_t pvr2_next_render_buffer()

{

    render_buffer_t result = NULL;

    uint32_t render_addr = MMIO_READ( PVR2, RENDER_ADDR1 );

    uint32_t render_mode = MMIO_READ( PVR2, RENDER_MODE );

    uint32_t render_scale = MMIO_READ( PVR2, RENDER_SCALER );

    uint32_t render_stride = MMIO_READ( PVR2, RENDER_SIZE ) << 3;

    if( render_addr & 0x01000000 ) { /* vram64 */

	render_addr = (render_addr & 0x00FFFFFF) + PVR2_RAM_BASE_INT;

    } else { /* vram32 */

	render_addr = (render_addr & 0x00FFFFFF) + PVR2_RAM_BASE;

    }

    int width = pvr2_scene_buffer_width();

    int height = pvr2_scene_buffer_height();

    int colour_format = pvr2_render_colour_format[render_mode&0x07];

    result = pvr2_alloc_render_buffer( render_addr, width, height );

    /* Setup the buffer */

    if( result != NULL ) {

	result->rowstride = render_stride;

	result->colour_format = colour_format;

	result->scale = render_scale;

	result->size = width * height * colour_formats[colour_format].bpp;

	result->flushed = FALSE;

	result->inverted = TRUE; // render buffers are inverted normally

    }

    return result;

}

static render_buffer_t pvr2_frame_buffer_to_render_buffer( frame_buffer_t frame )

{

    render_buffer_t result = pvr2_alloc_render_buffer( frame->address, frame->width, frame->height );

    if( result != NULL ) {

	int bpp = colour_formats[frame->colour_format].bpp;

	result->rowstride = frame->rowstride;

	result->colour_format = frame->colour_format;

	result->scale = 0x400;

	result->size = frame->width * frame->height * bpp;

	result->flushed = TRUE;

	result->inverted = frame->inverted;

	display_driver->load_frame_buffer( frame, result );

    }

    return result;

}