2 * $Id: asic.c,v 1.28 2007-01-31 10:58:42 nkeynes Exp $
4 * Support for the miscellaneous ASIC functions (Primarily event multiplexing,
7 * Copyright (c) 2005 Nathan Keynes.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #define MODULE asic_module
28 #include "dreamcast.h"
29 #include "maple/maple.h"
30 #include "gdrom/ide.h"
36 * 1) Does changing the mask after event occurance result in the
37 * interrupt being delivered immediately?
38 * TODO: Logic diagram of ASIC event/interrupt logic.
40 * ... don't even get me started on the "EXTDMA" page, about which, apparently,
41 * practically nothing is publicly known...
44 static void asic_check_cleared_events( void );
45 static void asic_init( void );
46 static void asic_reset( void );
47 static uint32_t asic_run_slice( uint32_t nanosecs );
48 static void asic_save_state( FILE *f );
49 static int asic_load_state( FILE *f );
50 static uint32_t g2_update_fifo_status( uint32_t slice_cycle );
52 struct dreamcast_module asic_module = { "ASIC", asic_init, asic_reset, NULL, asic_run_slice,
53 NULL, asic_save_state, asic_load_state };
55 #define G2_BIT5_TICKS 60
56 #define G2_BIT4_TICKS 160
57 #define G2_BIT0_ON_TICKS 120
58 #define G2_BIT0_OFF_TICKS 420
60 struct asic_g2_state {
68 static struct asic_g2_state g2_state;
70 static uint32_t asic_run_slice( uint32_t nanosecs )
72 g2_update_fifo_status(nanosecs);
73 if( g2_state.bit5_off_timer <= (int32_t)nanosecs ) {
74 g2_state.bit5_off_timer = -1;
76 g2_state.bit5_off_timer -= nanosecs;
79 if( g2_state.bit4_off_timer <= (int32_t)nanosecs ) {
80 g2_state.bit4_off_timer = -1;
82 g2_state.bit4_off_timer -= nanosecs;
84 if( g2_state.bit4_on_timer <= (int32_t)nanosecs ) {
85 g2_state.bit4_on_timer = -1;
87 g2_state.bit4_on_timer -= nanosecs;
90 if( g2_state.bit0_off_timer <= (int32_t)nanosecs ) {
91 g2_state.bit0_off_timer = -1;
93 g2_state.bit0_off_timer -= nanosecs;
95 if( g2_state.bit0_on_timer <= (int32_t)nanosecs ) {
96 g2_state.bit0_on_timer = -1;
98 g2_state.bit0_on_timer -= nanosecs;
104 static void asic_init( void )
106 register_io_region( &mmio_region_ASIC );
107 register_io_region( &mmio_region_EXTDMA );
111 static void asic_reset( void )
113 memset( &g2_state, 0xFF, sizeof(g2_state) );
116 static void asic_save_state( FILE *f )
118 fwrite( &g2_state, sizeof(g2_state), 1, f );
121 static int asic_load_state( FILE *f )
123 if( fread( &g2_state, sizeof(g2_state), 1, f ) != 1 )
131 * Setup the timers for the 3 FIFO status bits following a write through the G2
132 * bus from the SH4 side. The timing is roughly as follows: (times are
133 * approximate based on software readings - I wouldn't take this as gospel but
134 * it seems to be enough to fool most programs).
135 * 0ns: Bit 5 (Input fifo?) goes high immediately on the write
136 * 40ns: Bit 5 goes low and bit 4 goes high
137 * 120ns: Bit 4 goes low, bit 0 goes high
138 * 240ns: Bit 0 goes low.
140 * Additional writes while the FIFO is in operation extend the time that the
141 * bits remain high as one might expect, without altering the time at which
142 * they initially go high.
144 void asic_g2_write_word()
146 if( g2_state.bit5_off_timer < (int32_t)sh4r.slice_cycle ) {
147 g2_state.bit5_off_timer = sh4r.slice_cycle + G2_BIT5_TICKS;
149 g2_state.bit5_off_timer += G2_BIT5_TICKS;
152 if( g2_state.bit4_on_timer < (int32_t)sh4r.slice_cycle ) {
153 g2_state.bit4_on_timer = sh4r.slice_cycle + G2_BIT5_TICKS;
156 if( g2_state.bit4_off_timer < (int32_t)sh4r.slice_cycle ) {
157 g2_state.bit4_off_timer = g2_state.bit4_on_timer + G2_BIT4_TICKS;
159 g2_state.bit4_off_timer += G2_BIT4_TICKS;
162 if( g2_state.bit0_on_timer < (int32_t)sh4r.slice_cycle ) {
163 g2_state.bit0_on_timer = sh4r.slice_cycle + G2_BIT0_ON_TICKS;
166 if( g2_state.bit0_off_timer < (int32_t)sh4r.slice_cycle ) {
167 g2_state.bit0_off_timer = g2_state.bit0_on_timer + G2_BIT0_OFF_TICKS;
169 g2_state.bit0_off_timer += G2_BIT0_OFF_TICKS;
172 MMIO_WRITE( ASIC, G2STATUS, MMIO_READ(ASIC, G2STATUS) | 0x20 );
175 static uint32_t g2_update_fifo_status( uint32_t nanos )
177 uint32_t val = MMIO_READ( ASIC, G2STATUS );
178 if( ((uint32_t)g2_state.bit5_off_timer) <= nanos ) {
180 g2_state.bit5_off_timer = -1;
182 if( ((uint32_t)g2_state.bit4_on_timer) <= nanos ) {
184 g2_state.bit4_on_timer = -1;
186 if( ((uint32_t)g2_state.bit4_off_timer) <= nanos ) {
188 g2_state.bit4_off_timer = -1;
191 if( ((uint32_t)g2_state.bit0_on_timer) <= nanos ) {
193 g2_state.bit0_on_timer = -1;
195 if( ((uint32_t)g2_state.bit0_off_timer) <= nanos ) {
197 g2_state.bit0_off_timer = -1;
200 MMIO_WRITE( ASIC, G2STATUS, val );
204 static int g2_read_status() {
205 return g2_update_fifo_status( sh4r.slice_cycle );
209 void asic_event( int event )
211 int offset = ((event&0x60)>>3);
212 int result = (MMIO_READ(ASIC, PIRQ0 + offset)) |= (1<<(event&0x1F));
214 if( result & MMIO_READ(ASIC, IRQA0 + offset) )
215 intc_raise_interrupt( INT_IRQ13 );
216 if( result & MMIO_READ(ASIC, IRQB0 + offset) )
217 intc_raise_interrupt( INT_IRQ11 );
218 if( result & MMIO_READ(ASIC, IRQC0 + offset) )
219 intc_raise_interrupt( INT_IRQ9 );
221 if( event >= 64 ) { /* Third word */
222 asic_event( EVENT_CASCADE2 );
223 } else if( event >= 32 ) { /* Second word */
224 asic_event( EVENT_CASCADE1 );
228 void asic_clear_event( int event ) {
229 int offset = ((event&0x60)>>3);
230 uint32_t result = MMIO_READ(ASIC, PIRQ0 + offset) & (~(1<<(event&0x1F)));
231 MMIO_WRITE( ASIC, PIRQ0 + offset, result );
233 /* clear cascades if necessary */
235 MMIO_WRITE( ASIC, PIRQ0, MMIO_READ( ASIC, PIRQ0 ) & 0x7FFFFFFF );
236 } else if( event >= 32 ) {
237 MMIO_WRITE( ASIC, PIRQ0, MMIO_READ( ASIC, PIRQ0 ) & 0xBFFFFFFF );
241 asic_check_cleared_events();
244 void asic_check_cleared_events( )
246 int i, setA = 0, setB = 0, setC = 0;
248 for( i=0; i<3; i++ ) {
249 bits = MMIO_READ( ASIC, PIRQ0 + i );
250 setA |= (bits & MMIO_READ(ASIC, IRQA0 + i ));
251 setB |= (bits & MMIO_READ(ASIC, IRQB0 + i ));
252 setC |= (bits & MMIO_READ(ASIC, IRQC0 + i ));
255 intc_clear_interrupt( INT_IRQ13 );
257 intc_clear_interrupt( INT_IRQ11 );
259 intc_clear_interrupt( INT_IRQ9 );
262 void g2_dma_transfer( int channel )
264 uint32_t offset = channel << 5;
266 if( MMIO_READ( EXTDMA, G2DMA0CTL1 + offset ) == 1 ) {
267 if( MMIO_READ( EXTDMA, G2DMA0CTL2 + offset ) == 1 ) {
268 uint32_t extaddr = MMIO_READ( EXTDMA, G2DMA0EXT + offset );
269 uint32_t sh4addr = MMIO_READ( EXTDMA, G2DMA0SH4 + offset );
270 uint32_t length = MMIO_READ( EXTDMA, G2DMA0SIZ + offset ) & 0x1FFFFFFF;
271 uint32_t dir = MMIO_READ( EXTDMA, G2DMA0DIR + offset );
272 uint32_t mode = MMIO_READ( EXTDMA, G2DMA0MOD + offset );
274 if( dir == 0 ) { /* SH4 to device */
275 mem_copy_from_sh4( buf, sh4addr, length );
276 mem_copy_to_sh4( extaddr, buf, length );
277 } else { /* Device to SH4 */
278 mem_copy_from_sh4( buf, extaddr, length );
279 mem_copy_to_sh4( sh4addr, buf, length );
281 MMIO_WRITE( EXTDMA, G2DMA0CTL2 + offset, 0 );
282 asic_event( EVENT_G2_DMA0 + channel );
284 MMIO_WRITE( EXTDMA, G2DMA0CTL2 + offset, 0 );
289 void asic_ide_dma_transfer( )
291 if( MMIO_READ( EXTDMA, IDEDMACTL2 ) == 1 ) {
292 if( MMIO_READ( EXTDMA, IDEDMACTL1 ) == 1 ) {
293 MMIO_WRITE( EXTDMA, IDEDMATXSIZ, 0 );
295 uint32_t addr = MMIO_READ( EXTDMA, IDEDMASH4 );
296 uint32_t length = MMIO_READ( EXTDMA, IDEDMASIZ );
297 int dir = MMIO_READ( EXTDMA, IDEDMADIR );
299 uint32_t xfer = ide_read_data_dma( addr, length );
300 MMIO_WRITE( EXTDMA, IDEDMATXSIZ, xfer );
301 MMIO_WRITE( EXTDMA, IDEDMACTL2, 0 );
303 MMIO_WRITE( EXTDMA, IDEDMACTL2, 0 );
308 void pvr_dma_transfer( )
310 sh4addr_t destaddr = MMIO_READ( ASIC, PVRDMADEST) &0x1FFFFFE0;
311 uint32_t count = MMIO_READ( ASIC, PVRDMACNT );
312 char *data = alloca( count );
313 uint32_t rcount = DMAC_get_buffer( 2, data, count );
314 if( rcount != count )
315 WARN( "PVR received %08X bytes from DMA, expected %08X", rcount, count );
317 pvr2_dma_write( destaddr, data, rcount );
319 MMIO_WRITE( ASIC, PVRDMACTL, 0 );
320 MMIO_WRITE( ASIC, PVRDMACNT, 0 );
321 if( destaddr & 0x01000000 ) { /* Write to texture RAM */
322 MMIO_WRITE( ASIC, PVRDMADEST, destaddr + rcount );
324 asic_event( EVENT_PVR_DMA );
327 void mmio_region_ASIC_write( uint32_t reg, uint32_t val )
331 break; /* Treat this as read-only for the moment */
333 val = val & 0x3FFFFFFF; /* Top two bits aren't clearable */
334 MMIO_WRITE( ASIC, reg, MMIO_READ(ASIC, reg)&~val );
335 asic_check_cleared_events();
338 /* Clear any events */
339 val = MMIO_READ(ASIC, reg)&(~val);
340 MMIO_WRITE( ASIC, reg, val );
341 if( val == 0 ) { /* all clear - clear the cascade bit */
342 MMIO_WRITE( ASIC, PIRQ0, MMIO_READ( ASIC, PIRQ0 ) & 0x7FFFFFFF );
344 asic_check_cleared_events();
347 if( val == 0x7611 ) {
349 sh4r.new_pc = sh4r.pc;
351 WARN( "Unknown value %08X written to SYSRESET port", val );
355 MMIO_WRITE( ASIC, reg, val );
357 uint32_t maple_addr = MMIO_READ( ASIC, MAPLE_DMA) &0x1FFFFFE0;
358 maple_handle_buffer( maple_addr );
359 MMIO_WRITE( ASIC, reg, 0 );
363 MMIO_WRITE( ASIC, reg, (val & 0x03FFFFE0) | 0x10000000 );
366 MMIO_WRITE( ASIC, reg, val & 0x00FFFFE0 );
368 case PVRDMACTL: /* Initiate PVR DMA transfer */
370 MMIO_WRITE( ASIC, reg, val );
376 MMIO_WRITE( ASIC, reg, val );
379 MMIO_WRITE( ASIC, reg, val );
383 int32_t mmio_region_ASIC_read( uint32_t reg )
405 val = MMIO_READ(ASIC, reg);
408 return g2_read_status();
410 val = MMIO_READ(ASIC, reg);
416 MMIO_REGION_WRITE_FN( EXTDMA, reg, val )
418 if( !idereg.interface_enabled && IS_IDE_REGISTER(reg) ) {
419 return; /* disabled */
423 case IDEALTSTATUS: /* Device control */
424 ide_write_control( val );
427 ide_write_data_pio( val );
430 if( ide_can_write_regs() )
431 idereg.feature = (uint8_t)val;
434 if( ide_can_write_regs() )
435 idereg.count = (uint8_t)val;
438 if( ide_can_write_regs() )
439 idereg.lba0 = (uint8_t)val;
442 if( ide_can_write_regs() )
443 idereg.lba1 = (uint8_t)val;
446 if( ide_can_write_regs() )
447 idereg.lba2 = (uint8_t)val;
450 if( ide_can_write_regs() )
451 idereg.device = (uint8_t)val;
454 if( ide_can_write_regs() || val == IDE_CMD_NOP ) {
455 ide_write_command( (uint8_t)val );
459 MMIO_WRITE( EXTDMA, reg, val & 0x1FFFFFE0 );
462 MMIO_WRITE( EXTDMA, reg, val & 0x01FFFFFE );
466 MMIO_WRITE( EXTDMA, reg, val & 0x01 );
467 asic_ide_dma_transfer( );
470 if( val == 0x001FFFFF ) {
471 idereg.interface_enabled = TRUE;
472 /* Conventional wisdom says that this is necessary but not
473 * sufficient to enable the IDE interface.
475 } else if( val == 0x000042FE ) {
476 idereg.interface_enabled = FALSE;
481 MMIO_WRITE( EXTDMA, reg, val );
482 g2_dma_transfer( 0 );
488 MMIO_WRITE( EXTDMA, reg, val );
489 g2_dma_transfer( 1 );
496 MMIO_WRITE( EXTDMA, reg, val );
497 g2_dma_transfer( 2 );
503 MMIO_WRITE( EXTDMA, reg, val );
504 g2_dma_transfer( 3 );
511 ERROR( "Write to unimplemented DMA control register %08X", reg );
517 MMIO_WRITE( EXTDMA, reg, val );
521 MMIO_REGION_READ_FN( EXTDMA, reg )
524 if( !idereg.interface_enabled && IS_IDE_REGISTER(reg) ) {
525 return 0xFFFFFFFF; /* disabled */
532 case IDEDATA: return ide_read_data_pio( );
533 case IDEFEAT: return idereg.error;
534 case IDECOUNT:return idereg.count;
535 case IDELBA0: return ide_get_drive_status();
536 case IDELBA1: return idereg.lba1;
537 case IDELBA2: return idereg.lba2;
538 case IDEDEV: return idereg.device;
540 val = ide_read_status();
543 val = MMIO_READ( EXTDMA, reg );
.