xref: /netbsd-src/sys/arch/atari/dev/atari5380.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: atari5380.c,v 1.28 1997/08/27 11:23:39 bouyer Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Leo Weppelman.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Leo Weppelman.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/device.h>
37 #include <sys/buf.h>
38 #include <dev/scsipi/scsi_all.h>
39 #include <dev/scsipi/scsipi_all.h>
40 #include <dev/scsipi/scsi_message.h>
41 #include <dev/scsipi/scsiconf.h>
42 
43 #include <m68k/asm_single.h>
44 #include <m68k/cpu.h>
45 #include <m68k/cacheops.h>
46 
47 #include <atari/atari/stalloc.h>
48 
49 /*
50  * Include the driver definitions
51  */
52 #include <atari/dev/ncr5380reg.h>
53 
54 #include <machine/stdarg.h>
55 #include <machine/iomap.h>
56 #include <machine/mfp.h>
57 
58 #include <atari/atari/intr.h>
59 
60 #if defined(FALCON_SCSI)
61 #include <machine/dma.h>
62 #endif
63 
64 /*
65  * Set the various driver options
66  */
67 #define	NREQ		18	/* Size of issue queue			*/
68 #define	AUTO_SENSE	1	/* Automatically issue a request-sense 	*/
69 
70 #define	DRNAME		ncrscsi	/* used in various prints		*/
71 #undef	DBG_SEL			/* Show the selection process		*/
72 #undef	DBG_REQ			/* Show enqueued/ready requests		*/
73 #undef	DBG_ERR_RET		/* Show requests with != 0 return code	*/
74 #undef	DBG_NOWRITE		/* Do not allow writes to the targets	*/
75 #undef	DBG_PIO			/* Show the polled-I/O process		*/
76 #undef	DBG_INF			/* Show information transfer process	*/
77 #define	DBG_NOSTATIC		/* No static functions, all in DDB trace*/
78 #define	DBG_PID		15	/* Keep track of driver			*/
79 #define	REAL_DMA		/* Use DMA if sensible			*/
80 #if defined(FALCON_SCSI)
81 #define	REAL_DMA_POLL	1	/* 1: Poll for end of DMA-transfer	*/
82 #else
83 #define	REAL_DMA_POLL	0	/* 1: Poll for end of DMA-transfer	*/
84 #endif
85 #undef	USE_PDMA		/* Use special pdma-transfer function	*/
86 #define MIN_PHYS	65536	/*BARF!!!!*/
87 
88 /*
89  * Include more driver definitions
90  */
91 #include <atari/dev/ncr5380var.h>
92 
93 /*
94  * The atari specific driver options
95  */
96 #undef	NO_TTRAM_DMA		/* Do not use DMA to TT-ram. This	*/
97 				/*    fails on older atari's		*/
98 #define	ENABLE_NCR5380(sc)	cur_softc = sc;
99 
100 static u_char	*alloc_bounceb __P((u_long));
101 static void	free_bounceb __P((u_char *));
102 static int	machine_match __P((struct device *, void *, void *,
103 							struct cfdriver *));
104        void	scsi_ctrl __P((int));
105        void	scsi_dma __P((int));
106 
107 /*
108  * Functions that do nothing on the atari
109  */
110 #define	pdma_ready()		0
111 
112 #if defined(TT_SCSI)
113 
114 void	ncr5380_drq_intr __P((int));
115 
116 /*
117  * Define all the things we need of the DMA-controller
118  */
119 #define	SCSI_DMA	((struct scsi_dma *)AD_SCSI_DMA)
120 #define	SCSI_5380	((struct scsi_5380 *)AD_NCR5380)
121 
122 struct scsi_dma {
123 	volatile u_char		s_dma_ptr[8];	/* use only the odd bytes */
124 	volatile u_char		s_dma_cnt[8];	/* use only the odd bytes */
125 	volatile u_char		s_dma_res[4];	/* data residue register  */
126 	volatile u_char		s_dma_gap;	/* not used		  */
127 	volatile u_char		s_dma_ctrl;	/* control register	  */
128 	volatile u_char		s_dma_gap2;	/* not used		  */
129 	volatile u_char		s_hdma_ctrl;	/* Hades control register */
130 };
131 
132 #define	set_scsi_dma(addr, val)	(void)(					\
133 	{								\
134 	u_char	*address = (u_char*)addr+1;				\
135 	u_long	nval	 = (u_long)val;					\
136 	__asm("movepl	%0, %1@(0)": :"d" (nval), "a" (address));	\
137 	})
138 
139 #define	get_scsi_dma(addr, res)	(					\
140 	{								\
141 	u_char	*address = (u_char*)addr+1;				\
142 	u_long	nval;							\
143 	__asm("movepl	%1@(0), %0": "=d" (nval) : "a" (address));	\
144 	res = (u_long)nval;						\
145 	})
146 
147 /*
148  * Defines for TT-DMA control register
149  */
150 #define	SD_BUSERR	0x80		/* 1 = transfer caused bus error*/
151 #define	SD_ZERO		0x40		/* 1 = byte counter is zero	*/
152 #define	SD_ENABLE	0x02		/* 1 = Enable DMA		*/
153 #define	SD_OUT		0x01		/* Direction: memory to SCSI	*/
154 #define	SD_IN		0x00		/* Direction: SCSI to memory	*/
155 
156 /*
157  * Defines for Hades-DMA control register
158  */
159 #define	SDH_BUSERR	0x02		/* 1 = Bus error		*/
160 #define SDH_EOP		0x01		/* 1 = Signal EOP on 5380	*/
161 #define	SDH_ZERO	0x40		/* 1 = Byte counter is zero	*/
162 
163 /*
164  * Define the 5380 register set
165  */
166 struct scsi_5380 {
167 	volatile u_char	scsi_5380[16];	/* use only the odd bytes	*/
168 };
169 #endif /* TT_SCSI */
170 
171 /**********************************************
172  * Variables present for both TT and Falcon.  *
173  **********************************************/
174 
175 /*
176  * Softc of currently active controller (a bit of fake; we only have one)
177  */
178 static struct ncr_softc	*cur_softc;
179 
180 #if defined(TT_SCSI) && !defined(FALCON_SCSI)
181 /*
182  * We can be more efficient for some functions when only TT_SCSI is selected
183  */
184 #define	GET_5380_REG(rnum)	SCSI_5380->scsi_5380[(rnum << 1) | 1]
185 #define	SET_5380_REG(rnum,val)	(SCSI_5380->scsi_5380[(rnum << 1) | 1] = val)
186 
187 #define scsi_mach_init(sc)	scsi_tt_init(sc)
188 #define scsi_ienable()		scsi_tt_ienable()
189 #define scsi_idisable()		scsi_tt_idisable()
190 #define	scsi_clr_ipend()	scsi_tt_clr_ipend()
191 #define scsi_ipending()		(GET_5380_REG(NCR5380_DMSTAT) & SC_IRQ_SET)
192 #define scsi_dma_setup(r,p,m)	scsi_tt_dmasetup(r, p, m)
193 #define wrong_dma_range(r,d)	tt_wrong_dma_range(r, d)
194 #define poll_edma(reqp)		tt_poll_edma(reqp)
195 #define get_dma_result(r, b)	tt_get_dma_result(r, b)
196 #define	can_access_5380()	1
197 #define emulated_dma()		((machineid & ATARI_HADES) ? 1 : 0)
198 
199 #define fair_to_keep_dma()	1
200 #define claimed_dma()		1
201 #define reconsider_dma()
202 
203 #endif /* defined(TT_SCSI) && !defined(FALCON_SCSI) */
204 
205 #if defined(TT_SCSI)
206 
207 /*
208  * Prototype functions defined below
209  */
210 #ifdef NO_TTRAM_DMA
211 static int tt_wrong_dma_range __P((SC_REQ *, struct dma_chain *));
212 #endif
213 static void	scsi_tt_init __P((struct ncr_softc *));
214 static u_char	get_tt_5380_reg __P((u_short));
215 static void	set_tt_5380_reg __P((u_short, u_short));
216 static void	scsi_tt_dmasetup __P((SC_REQ *, u_int, u_char));
217 static int	tt_poll_edma __P((SC_REQ *));
218 static u_char	*ptov __P((SC_REQ *, u_long*));
219 static int	tt_get_dma_result __P((SC_REQ *, u_long *));
220        void	scsi_tt_ienable __P((void));
221        void	scsi_tt_idisable __P((void));
222        void	scsi_tt_clr_ipend __P((void));
223 
224 /*
225  * Define these too, so we can use them locally...
226  */
227 #define	GET_TT_REG(rnum)	SCSI_5380->scsi_5380[(rnum << 1) | 1]
228 #define	SET_TT_REG(rnum,val)	(SCSI_5380->scsi_5380[(rnum << 1) | 1] = val)
229 
230 #ifdef NO_TTRAM_DMA
231 static int
232 tt_wrong_dma_range(reqp, dm)
233 SC_REQ			*reqp;
234 struct dma_chain	*dm;
235 {
236 	if (dm->dm_addr & 0xff000000) {
237 		reqp->dr_flag |= DRIVER_BOUNCING;
238 		return(1);
239 	}
240 	return(0);
241 }
242 #else
243 #define	tt_wrong_dma_range(reqp, dm)	0
244 #endif
245 
246 static void
247 scsi_tt_init(struct ncr_softc *sc)
248 {
249 	/*
250 	 * Enable SCSI-related interrupts
251 	 */
252 	MFP2->mf_aer  |= 0x80;		/* SCSI IRQ goes HIGH!!!!!	*/
253 
254 	if (machineid & ATARI_TT) {
255 		/* SCSI-dma interrupts		*/
256 		MFP2->mf_ierb |= IB_SCDM;
257 		MFP2->mf_iprb &= ~IB_SCDM;
258 		MFP2->mf_imrb |= IB_SCDM;
259 	}
260 	else if (machineid & ATARI_HADES) {
261 		SCSI_DMA->s_hdma_ctrl = 0;
262 
263 		if (intr_establish(2, AUTO_VEC, 0,
264 					(hw_ifun_t)ncr5380_drq_intr,
265 					NULL) == NULL)
266 		panic("scsi_tt_init: Can't establish drq-interrupt");
267 	}
268 	else panic("scsi_tt_init: should not come here");
269 
270 	MFP2->mf_iera |= IA_SCSI;	/* SCSI-5380 interrupts		*/
271 	MFP2->mf_ipra &= ~IA_SCSI;
272 	MFP2->mf_imra |= IA_SCSI;
273 
274 	/*
275 	 * LWP: DMA transfers to TT-ram causes data to be garbeled
276 	 * without notice on some revisons of the TT-mainboard.
277 	 * When program's generate misterious Segmentations faults,
278 	 * try turning on NO_TTRAM_DMA.
279 	 */
280 #ifdef NO_TTRAM_DMA
281 	printf(": DMA to TT-RAM is disabled!");
282 #endif
283 }
284 
285 static u_char
286 get_tt_5380_reg(u_short rnum)
287 {
288 	return(SCSI_5380->scsi_5380[(rnum << 1) | 1]);
289 }
290 
291 static void
292 set_tt_5380_reg(u_short rnum, u_short val)
293 {
294 	SCSI_5380->scsi_5380[(rnum << 1) | 1] = val;
295 }
296 
297 extern __inline__ void
298 scsi_tt_ienable(void)
299 {
300 	if (machineid & ATARI_TT)
301 		single_inst_bset_b(MFP2->mf_imrb, IB_SCDM);
302 	single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
303 }
304 
305 extern __inline__ void
306 scsi_tt_idisable(void)
307 {
308 	if (machineid & ATARI_TT)
309 		single_inst_bclr_b(MFP2->mf_imrb, IB_SCDM);
310 	single_inst_bclr_b(MFP2->mf_imra, IA_SCSI);
311 }
312 
313 extern __inline__ void
314 scsi_tt_clr_ipend(void)
315 {
316 	int	tmp;
317 
318 	SCSI_DMA->s_dma_ctrl = 0;
319 	tmp = GET_TT_REG(NCR5380_IRCV);
320 	if (machineid & ATARI_TT)
321 		single_inst_bclr_b(MFP2->mf_iprb, IB_SCDM);
322 	single_inst_bclr_b(MFP2->mf_ipra, IA_SCSI);
323 
324 	/*
325 	 * Remove interrupts already scheduled.
326 	 */
327 	rem_sicallback((si_farg)ncr_ctrl_intr);
328 	rem_sicallback((si_farg)ncr_dma_intr);
329 }
330 
331 static void
332 scsi_tt_dmasetup(SC_REQ *reqp, u_int phase, u_char	mode)
333 {
334 	if (PH_IN(phase)) {
335 		SCSI_DMA->s_dma_ctrl = SD_IN;
336 		if (machineid & ATARI_HADES)
337 		    SCSI_DMA->s_hdma_ctrl &= ~(SDH_BUSERR|SDH_EOP);
338 		set_scsi_dma(&(SCSI_DMA->s_dma_ptr), reqp->dm_cur->dm_addr);
339 		set_scsi_dma(&(SCSI_DMA->s_dma_cnt), reqp->dm_cur->dm_count);
340 		SET_TT_REG(NCR5380_ICOM, 0);
341 		SET_TT_REG(NCR5380_MODE, mode);
342 		SCSI_DMA->s_dma_ctrl = SD_ENABLE;
343 		SET_TT_REG(NCR5380_IRCV, 0);
344 	}
345 	else {
346 		SCSI_DMA->s_dma_ctrl = SD_OUT;
347 		if (machineid & ATARI_HADES)
348 		    SCSI_DMA->s_hdma_ctrl &= ~(SDH_BUSERR|SDH_EOP);
349 		set_scsi_dma(&(SCSI_DMA->s_dma_ptr), reqp->dm_cur->dm_addr);
350 		set_scsi_dma(&(SCSI_DMA->s_dma_cnt), reqp->dm_cur->dm_count);
351 		SET_TT_REG(NCR5380_MODE, mode);
352 		SET_TT_REG(NCR5380_ICOM, SC_ADTB);
353 		SET_TT_REG(NCR5380_DMSTAT, 0);
354 		SCSI_DMA->s_dma_ctrl = SD_ENABLE|SD_OUT;
355 	}
356 }
357 
358 static int
359 tt_poll_edma(SC_REQ *reqp)
360 {
361 	u_char	dmstat, dmastat;
362 	int	timeout = 9000; /* XXX */
363 
364 	/*
365 	 * We wait here until the DMA has finished. This can be
366 	 * achieved by checking the following conditions:
367 	 *   - 5380:
368 	 *	- End of DMA flag is set
369 	 *	- We lost BSY (error!!)
370 	 *	- A phase mismatch has occured (partial transfer)
371 	 *   - DMA-controller:
372 	 *	- A bus error occurred (Kernel error!!)
373 	 *	- All bytes are transferred
374 	 * If one of the terminating conditions was met, we call
375 	 * 'dma_ready' to check errors and perform the bookkeeping.
376 	 */
377 
378 	for (;;) {
379 		delay(20);
380 		if (--timeout <= 0) {
381 			ncr_tprint(reqp, "timeout on polled transfer\n");
382 			reqp->xs->error = XS_TIMEOUT;
383 			return(0);
384 		}
385 		dmstat  = GET_TT_REG(NCR5380_DMSTAT);
386 
387 		if ((machineid & ATARI_HADES) && (dmstat & SC_DMA_REQ)) {
388 			ncr5380_drq_intr(1);
389 			dmstat  = GET_TT_REG(NCR5380_DMSTAT);
390 		}
391 
392 		dmastat = SCSI_DMA->s_dma_ctrl;
393 		if (dmstat & (SC_END_DMA|SC_BSY_ERR|SC_IRQ_SET))
394 			break;
395 		if (!(dmstat & SC_PHS_MTCH))
396 			break;
397 		if (dmastat & (SD_BUSERR|SD_ZERO))
398 			break;
399 	}
400 	return(1);
401 }
402 
403 /*
404  * Convert physical DMA address to a virtual address.
405  */
406 static u_char *
407 ptov(SC_REQ *reqp, u_long *phaddr)
408 {
409 	struct dma_chain	*dm;
410 	u_char			*vaddr;
411 
412 	dm = reqp->dm_chain;
413 	vaddr = reqp->xdata_ptr;
414 	for(; dm < reqp->dm_cur; dm++)
415 		vaddr += dm->dm_count;
416 	vaddr += (u_long)phaddr - dm->dm_addr;
417 	return(vaddr);
418 }
419 
420 static int
421 tt_get_dma_result(SC_REQ *reqp, u_long *bytes_left)
422 {
423 	int	dmastat, dmstat;
424 	u_char	*byte_p;
425 	u_long	leftover;
426 
427 	dmastat = SCSI_DMA->s_dma_ctrl;
428 	dmstat  = GET_TT_REG(NCR5380_DMSTAT);
429 	get_scsi_dma(SCSI_DMA->s_dma_cnt, leftover);
430 	get_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)byte_p);
431 
432 	if (dmastat & SD_BUSERR) {
433 		/*
434 		 * The DMA-controller seems to access 8 bytes beyond
435 		 * it's limits on output. Therefore check also the byte
436 		 * count. If it's zero, ignore the bus error.
437 		 */
438 		if (leftover != 0) {
439 			ncr_tprint(reqp,
440 				"SCSI-DMA buserror - accessing 0x%x\n", byte_p);
441 			reqp->xs->error = XS_DRIVER_STUFFUP;
442 		}
443 	}
444 
445 	/*
446 	 * We handle the following special condition below:
447 	 *  -- The device disconnects in the middle of a write operation --
448 	 * In this case, the 5380 has already pre-fetched the next byte from
449 	 * the DMA-controller before the phase mismatch occurs. Therefore,
450 	 * leftover is 1 too low.
451 	 * This does not always happen! Therefore, we only do this when
452 	 * leftover is odd. This assumes that DMA transfers are _even_! This
453 	 * is normally the case on disks and types but might not always be.
454 	 * XXX: Check if ACK is consistently high on these occasions LWP
455 	 */
456 	if ((leftover & 1) && !(dmstat & SC_PHS_MTCH) && PH_OUT(reqp->phase))
457 		leftover++;
458 
459 	/*
460 	 * Check if there are some 'restbytes' left in the DMA-controller.
461 	 */
462 	if ((machineid & ATARI_TT) && ((u_long)byte_p & 3)
463 	    && PH_IN(reqp->phase)) {
464 		u_char	*p, *q;
465 
466 		p = ptov(reqp, (u_long *)((u_long)byte_p & ~3));
467 		q = (u_char*)&(SCSI_DMA->s_dma_res);
468 		switch ((u_long)byte_p & 3) {
469 			case 3: *p++ = *q++;
470 			case 2: *p++ = *q++;
471 			case 1: *p++ = *q++;
472 		}
473 	}
474 	*bytes_left = leftover;
475 	return ((dmastat & (SD_BUSERR|SD_ZERO)) ? 1 : 0);
476 }
477 
478 static u_char *dma_ptr;
479 void
480 ncr5380_drq_intr(poll)
481 int poll;
482 {
483 extern	int			*nofault;
484 	label_t			faultbuf;
485 	int			write;
486 	u_long	 		count;
487 	u_char			*data_p = (u_char*)(stio_addr+0x741);
488 
489 	/*
490 	 * Block SCSI interrupts while emulating DMA. They come
491 	 * at a higher priority.
492 	 */
493 	single_inst_bclr_b(MFP2->mf_imra, IA_SCSI);
494 
495 	/*
496 	 * Setup for a possible bus error caused by SCSI controller
497 	 * switching out of DATA-IN/OUT before we're done with the
498 	 * current transfer.
499 	 */
500 	nofault = (int *) &faultbuf;
501 
502 	if (setjmp((label_t *) nofault)) {
503 		u_char	*ptr;
504 		u_long	cnt, tmp;
505 
506 		PID("drq berr");
507 		nofault = (int *) 0;
508 
509 		/*
510 		 * Determine number of bytes transferred
511 		 */
512 		get_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)ptr);
513 		cnt = dma_ptr - ptr;
514 
515 		if (cnt != 0) {
516 			/*
517 			 * Update the dma pointer/count fields
518 			 */
519 			set_scsi_dma(SCSI_DMA->s_dma_ptr, dma_ptr);
520 			get_scsi_dma(SCSI_DMA->s_dma_cnt, tmp);
521 			set_scsi_dma(SCSI_DMA->s_dma_cnt, tmp - cnt);
522 
523 			if (tmp > cnt) {
524 				/*
525 				 * Still more to transfer
526 				 */
527 				if (!poll)
528 				   single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
529 				return;
530 			}
531 
532 			/*
533 			 * Signal EOP to 5380
534 			 */
535 			SCSI_DMA->s_hdma_ctrl |= SDH_EOP;
536 		}
537 		else {
538 			nofault = (int *) &faultbuf;
539 
540 			/*
541 			 * Try to figure out if the byte-count was
542 			 * zero because there was no (more) data or
543 			 * because the dma_ptr is bogus.
544 			 */
545 			if (setjmp((label_t *) nofault)) {
546 				/*
547 				 * Set the bus-error bit
548 				 */
549 				SCSI_DMA->s_hdma_ctrl |= SDH_BUSERR;
550 			}
551 			__asm __volatile ("tstb	%0@(0)": : "a" (dma_ptr));
552 			nofault = (int *)0;
553 		}
554 
555 		/*
556 		 * Schedule an interrupt
557 		 */
558 		if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
559 		    add_sicallback((si_farg)ncr_dma_intr, (void *)cur_softc, 0);
560 
561 		/*
562 		 * Clear DMA-mode
563 		 */
564 		SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;
565 		if (!poll)
566 			single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
567 
568 		return;
569 	}
570 
571 	write = (SCSI_DMA->s_dma_ctrl & SD_OUT) ? 1 : 0;
572 #if DBG_PID
573 	if (write) {
574 		PID("drq (in)");
575 	} else {
576 		PID("drq (out)");
577 	}
578 #endif
579 
580 	get_scsi_dma(SCSI_DMA->s_dma_cnt, count);
581 	get_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)dma_ptr);
582 
583 	/*
584 	 * Keep pushing bytes until we're done or a bus-error
585 	 * signals that the SCSI controller is not ready.
586 	 * NOTE: I tried some optimalizations in these loops,
587 	 *       but they had no effect on transfer speed.
588 	 */
589 	if (write) {
590 		while(count--) {
591 			*data_p = *dma_ptr++;
592 		}
593 	}
594 	else {
595 		while(count--) {
596 			*dma_ptr++ = *data_p;
597 		}
598 	}
599 
600 	/*
601 	 * Schedule an interrupt
602 	 */
603 	if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
604 	    add_sicallback((si_farg)ncr_dma_intr, (void *)cur_softc, 0);
605 
606 	/*
607 	 * Clear DMA-mode
608 	 */
609 	SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;
610 
611 	/*
612 	 * OK.  No bus error occurred above.  Clear the nofault flag
613 	 * so we no longer short-circuit bus errors.
614 	 */
615 	nofault = (int *) 0;
616 
617 	/*
618 	 * Update the DMA 'registers' to reflect that all bytes
619 	 * have been transfered and tell this to the 5380 too.
620 	 */
621 	set_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)dma_ptr);
622 	set_scsi_dma(SCSI_DMA->s_dma_cnt, 0);
623 	SCSI_DMA->s_hdma_ctrl |= SDH_EOP;
624 
625 	PID("end drq");
626 	if (!poll)
627 		single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
628 
629 	return;
630 }
631 
632 #endif /* defined(TT_SCSI) */
633 
634 #if defined(FALCON_SCSI) && !defined(TT_SCSI)
635 
636 #define	GET_5380_REG(rnum)	get_falcon_5380_reg(rnum)
637 #define	SET_5380_REG(rnum,val)	set_falcon_5380_reg(rnum, val)
638 #define scsi_mach_init(sc)	scsi_falcon_init(sc)
639 #define scsi_ienable()		scsi_falcon_ienable()
640 #define scsi_idisable()		scsi_falcon_idisable()
641 #define	scsi_clr_ipend()	scsi_falcon_clr_ipend()
642 #define	scsi_ipending()		scsi_falcon_ipending()
643 #define scsi_dma_setup(r,p,m)	scsi_falcon_dmasetup(r, p, m)
644 #define wrong_dma_range(r,d)	falcon_wrong_dma_range(r, d)
645 #define poll_edma(reqp)		falcon_poll_edma(reqp)
646 #define get_dma_result(r, b)	falcon_get_dma_result(r, b)
647 #define	can_access_5380()	falcon_can_access_5380()
648 #define	emulated_dma()		0
649 
650 #define fair_to_keep_dma()	(!st_dmawanted())
651 #define claimed_dma()		falcon_claimed_dma()
652 #define reconsider_dma()	falcon_reconsider_dma()
653 
654 #endif /* defined(FALCON_SCSI) && !defined(TT_SCSI) */
655 
656 #if defined(FALCON_SCSI)
657 
658 /*
659  * Prototype functions defined below
660  */
661 static void	scsi_falcon_init __P((struct ncr_softc *));
662 static u_char	get_falcon_5380_reg __P((u_short));
663 static void	set_falcon_5380_reg __P((u_short, u_short));
664 static int	falcon_wrong_dma_range __P((SC_REQ *, struct dma_chain *));
665 static void	fal1_dma __P((u_int, u_int, SC_REQ *));
666 static void	scsi_falcon_dmasetup __P((SC_REQ  *, u_int, u_char));
667 static int	falcon_poll_edma __P((SC_REQ  *));
668 static int	falcon_get_dma_result __P((SC_REQ  *, u_long *));
669        int	falcon_can_access_5380 __P((void));
670        void	scsi_falcon_clr_ipend __P((void));
671        void	scsi_falcon_idisable __P((void));
672        void	scsi_falcon_ienable __P((void));
673        int	scsi_falcon_ipending __P((void));
674        int	falcon_claimed_dma __P((void));
675        void	falcon_reconsider_dma __P((void));
676 
677 static void
678 scsi_falcon_init(sc)
679 struct ncr_softc	*sc;
680 {
681 	/*
682 	 * Enable disk related interrupts
683 	 */
684 	MFP->mf_ierb  |= IB_DINT;
685 	MFP->mf_iprb  &= ~IB_DINT;
686 	MFP->mf_imrb  |= IB_DINT;
687 }
688 
689 static u_char
690 get_falcon_5380_reg(rnum)
691 u_short	rnum;
692 {
693 	DMA->dma_mode = DMA_SCSI + rnum;
694 	return(DMA->dma_data);
695 }
696 
697 static void
698 set_falcon_5380_reg(rnum, val)
699 u_short	rnum, val;
700 {
701 	DMA->dma_mode = DMA_SCSI + rnum;
702 	DMA->dma_data = val;
703 }
704 
705 extern __inline__ void
706 scsi_falcon_ienable()
707 {
708 	single_inst_bset_b(MFP->mf_imrb, IB_DINT);
709 }
710 
711 extern __inline__ void
712 scsi_falcon_idisable()
713 {
714 	single_inst_bclr_b(MFP->mf_imrb, IB_DINT);
715 }
716 
717 extern __inline__ void
718 scsi_falcon_clr_ipend()
719 {
720 	int	tmp;
721 
722 	tmp = get_falcon_5380_reg(NCR5380_IRCV);
723 	rem_sicallback((si_farg)ncr_ctrl_intr);
724 }
725 
726 extern __inline__ int
727 scsi_falcon_ipending()
728 {
729 	if (connected && (connected->dr_flag & DRIVER_IN_DMA)) {
730 		/*
731 		 *  XXX: When DMA is running, we are only allowed to
732 		 *       check the 5380 when DMA _might_ be finished.
733 		 */
734 		if (MFP->mf_gpip & IO_DINT)
735 		    return (0); /* XXX: Actually: we're not allowed to check */
736 
737 		/* LWP: 28-06, must be a dma interrupt! should the
738 		 * ST-DMA unit be taken out of dma mode?????
739 		 */
740 		DMA->dma_mode = 0x90;
741 
742 	}
743 	return(get_falcon_5380_reg(NCR5380_DMSTAT) & SC_IRQ_SET);
744 }
745 
746 static int
747 falcon_wrong_dma_range(reqp, dm)
748 SC_REQ			*reqp;
749 struct dma_chain	*dm;
750 {
751 	/*
752 	 * Do not allow chains yet! See also comment with
753 	 * falcon_poll_edma() !!!
754 	 */
755 	if (((dm - reqp->dm_chain) > 0) || (dm->dm_addr & 0xff000000)) {
756 		reqp->dr_flag |= DRIVER_BOUNCING;
757 		return(1);
758 	}
759 	/*
760 	 * Never allow DMA to happen on a Falcon when the transfer
761 	 * size is no multiple of 512. This is the transfer unit of the
762 	 * ST DMA-controller.
763 	 */
764 	if(dm->dm_count & 511)
765 		return(1);
766 	return(0);
767 }
768 
769 static	int falcon_lock = 0;
770 
771 extern __inline__ int
772 falcon_claimed_dma()
773 {
774 	if (falcon_lock != DMA_LOCK_GRANT) {
775 		if (falcon_lock == DMA_LOCK_REQ) {
776 			/*
777 			 * DMA access is being claimed.
778 			 */
779 			return(0);
780 		}
781 		if (!st_dmagrab((dma_farg)ncr_ctrl_intr, (dma_farg)run_main,
782 						cur_softc, &falcon_lock, 1))
783 			return(0);
784 	}
785 	return(1);
786 }
787 
788 extern __inline__ void
789 falcon_reconsider_dma()
790 {
791 	if (falcon_lock && (connected == NULL) && (discon_q == NULL)) {
792 		/*
793 		 * No need to keep DMA locked by us as we are not currently
794 		 * connected and no disconnected jobs are pending.
795 		 */
796 		rem_sicallback((si_farg)ncr_ctrl_intr);
797 		st_dmafree(cur_softc, &falcon_lock);
798 	}
799 
800 	if (!falcon_lock && (issue_q != NULL)) {
801 		/*
802 		 * We must (re)claim DMA access as there are jobs
803 		 * waiting in the issue queue.
804 		 */
805 		st_dmagrab((dma_farg)ncr_ctrl_intr, (dma_farg)run_main,
806 						cur_softc, &falcon_lock, 0);
807 	}
808 }
809 
810 static void
811 fal1_dma(dir, nsects, reqp)
812 u_int	dir, nsects;
813 SC_REQ	*reqp;
814 {
815 	dir <<= 8;
816 	st_dmaaddr_set((caddr_t)reqp->dm_cur->dm_addr);
817 	DMA->dma_mode = 0x90 | dir;
818 	DMA->dma_mode = 0x90 | (dir ^ DMA_WRBIT);
819 	DMA->dma_mode = 0x90 | dir;
820 	DMA->dma_data = nsects;
821 	delay(2);	/* _really_ needed (Thomas Gerner) */
822 	DMA->dma_mode = 0x10 | dir;
823 }
824 
825 static void
826 scsi_falcon_dmasetup(reqp, phase, mode)
827 SC_REQ	*reqp;
828 u_int	phase;
829 u_char	mode;
830 {
831 	int	nsects = reqp->dm_cur->dm_count / 512; /* XXX */
832 
833 	/*
834 	 * XXX: We should probably clear the fifo before putting the
835 	 *      5380 into DMA-mode.
836 	 */
837 	if (PH_IN(phase)) {
838 		set_falcon_5380_reg(NCR5380_ICOM, 0);
839 		set_falcon_5380_reg(NCR5380_MODE, mode);
840 		set_falcon_5380_reg(NCR5380_IRCV, 0);
841 		fal1_dma(0, nsects, reqp);
842 	}
843 	else {
844 		set_falcon_5380_reg(NCR5380_MODE, mode);
845 		set_falcon_5380_reg(NCR5380_ICOM, SC_ADTB);
846 		set_falcon_5380_reg(NCR5380_DMSTAT, 0);
847 		fal1_dma(1, nsects, reqp);
848 	}
849 }
850 
851 static int
852 falcon_poll_edma(reqp)
853 SC_REQ	*reqp;
854 {
855 	int	timeout = 9000; /* XXX */
856 
857 	/*
858 	 * Because of the Falcon hardware, it is impossible to reach
859 	 * the 5380 while doing DMA-transfers. So we have to rely on
860 	 * the interrupt line to determine if DMA-has finished. the
861 	 * DMA-controller itself will never fire an interrupt. This means
862 	 * that 'broken-up' DMA transfers are not (yet) possible on the
863 	 * Falcon.
864 	 */
865 	for (;;) {
866 		delay(20);
867 		if (--timeout <= 0) {
868 			ncr_tprint(reqp, "Timeout on polled transfer\n");
869 			reqp->xs->error = XS_TIMEOUT;
870 			return(0);
871 		}
872 		if (!(MFP->mf_gpip & IO_DINT))
873 			break;
874 	}
875 	return(1);
876 }
877 
878 static int
879 falcon_get_dma_result(reqp, bytes_left)
880 SC_REQ	*reqp;
881 u_long	*bytes_left;
882 {
883 	int	rv = 0;
884 	int	st_dmastat;
885 	u_long	bytes_done;
886 
887 	/*
888 	 * Select sector counter register first (See Atari docu.)
889 	 */
890 	DMA->dma_mode = 0x90;
891 	if (!(st_dmastat = DMA->dma_stat) & 0x01) {
892 		/*
893 		 * Misc. DMA-error according to Atari...
894 		 */
895 		ncr_tprint(reqp, "Unknow ST-SCSI error near 0x%x\n",
896 							st_dmaaddr_get());
897 		reqp->xs->error = XS_DRIVER_STUFFUP;
898 		rv = 1;
899 	}
900 	/*
901 	 * Because we NEVER start DMA on the Falcon when the data size
902 	 * is not a multiple of 512 bytes, we can safely round down the
903 	 * byte count on writes. We need to because in case of a disconnect,
904 	 * the DMA has already prefetched the next couple of bytes.
905 	 * On read, these byte counts are an error. They are logged and
906 	 * should be handled by the mi-part of the driver.
907 	 * NOTE: We formerly did this by using the 'byte-count-zero' bit
908 	 *       of the DMA controller, but this didn't seem to work???
909          *       [lwp 29/06/96]
910 	 */
911 	bytes_done = st_dmaaddr_get() - reqp->dm_cur->dm_addr;
912 	if (bytes_done & 511) {
913 		if (PH_IN(reqp->phase)) {
914 			ncr_tprint(reqp, "Byte count on read not a multiple "
915 					 "of 512 (%ld)\n", bytes_done);
916 		}
917 		bytes_done &= ~511;
918 	}
919 	if ((*bytes_left = reqp->dm_cur->dm_count - bytes_done) == 0)
920 		rv = 1;
921 	return(rv);
922 }
923 
924 static int
925 falcon_can_access_5380()
926 {
927 	if (connected && (connected->dr_flag & DRIVER_IN_DMA)
928 		&& (MFP->mf_gpip & IO_DINT))
929 			return(0);
930 	return(1);
931 }
932 
933 #endif /* defined(FALCON_SCSI) */
934 
935 #if defined(TT_SCSI) && defined(FALCON_SCSI)
936 /*
937  * Define some functions to support _both_ TT and Falcon SCSI
938  */
939 
940 /*
941  * The prototypes first...
942  */
943 static void	scsi_mach_init __P((struct ncr_softc *));
944        void	scsi_ienable __P((void));
945        void	scsi_idisable __P((void));
946        void	scsi_clr_ipend __P((void));
947        int	scsi_ipending __P((void));
948        void	scsi_dma_setup __P((SC_REQ *, u_int, u_char));
949        int	wrong_dma_range __P((SC_REQ *, struct dma_chain *));
950        int	poll_edma __P((SC_REQ *));
951        int	get_dma_result __P((SC_REQ *, u_long *));
952        int	can_access_5380 __P((void));
953 
954 /*
955  * Register access will be done through the following 2 function pointers.
956  */
957 static u_char	(*get_5380_reg) __P((u_short));
958 static void	(*set_5380_reg) __P((u_short, u_short));
959 
960 #define	GET_5380_REG	(*get_5380_reg)
961 #define	SET_5380_REG	(*set_5380_reg)
962 
963 static void
964 scsi_mach_init(sc)
965 struct ncr_softc	*sc;
966 {
967 	if (machineid & ATARI_FALCON) {
968 		get_5380_reg = get_falcon_5380_reg;
969 		set_5380_reg = set_falcon_5380_reg;
970 		scsi_falcon_init(sc);
971 	}
972 	else {
973 		get_5380_reg = get_tt_5380_reg;
974 		set_5380_reg = set_tt_5380_reg;
975 		scsi_tt_init(sc);
976 	}
977 }
978 
979 extern __inline__ void
980 scsi_ienable()
981 {
982 	if (machineid & ATARI_FALCON)
983 		scsi_falcon_ienable();
984 	else scsi_tt_ienable();
985 }
986 
987 extern __inline__ void
988 scsi_idisable()
989 {
990 	if (machineid & ATARI_FALCON)
991 		scsi_falcon_idisable();
992 	else scsi_tt_idisable();
993 }
994 
995 extern __inline__ void
996 scsi_clr_ipend()
997 {
998 	if (machineid & ATARI_FALCON)
999 		scsi_falcon_clr_ipend();
1000 	else scsi_tt_clr_ipend();
1001 }
1002 
1003 extern __inline__ int
1004 scsi_ipending()
1005 {
1006 	if (machineid & ATARI_FALCON)
1007 		return(scsi_falcon_ipending());
1008 	else return (GET_TT_REG(NCR5380_DMSTAT) & SC_IRQ_SET);
1009 }
1010 
1011 extern __inline__ void
1012 scsi_dma_setup(reqp, phase, mbase)
1013 SC_REQ	*reqp;
1014 u_int	phase;
1015 u_char	mbase;
1016 {
1017 	if (machineid & ATARI_FALCON)
1018 		scsi_falcon_dmasetup(reqp, phase, mbase);
1019 	else scsi_tt_dmasetup(reqp, phase, mbase);
1020 }
1021 
1022 extern __inline__ int
1023 wrong_dma_range(reqp, dm)
1024 SC_REQ			*reqp;
1025 struct dma_chain	*dm;
1026 {
1027 	if (machineid & ATARI_FALCON)
1028 		return(falcon_wrong_dma_range(reqp, dm));
1029 	else return(tt_wrong_dma_range(reqp, dm));
1030 }
1031 
1032 extern __inline__ int
1033 poll_edma(reqp)
1034 SC_REQ	*reqp;
1035 {
1036 	if (machineid & ATARI_FALCON)
1037 		return(falcon_poll_edma(reqp));
1038 	else return(tt_poll_edma(reqp));
1039 }
1040 
1041 extern __inline__ int
1042 get_dma_result(reqp, bytes_left)
1043 SC_REQ	*reqp;
1044 u_long	*bytes_left;
1045 {
1046 	if (machineid & ATARI_FALCON)
1047 		return(falcon_get_dma_result(reqp, bytes_left));
1048 	else return(tt_get_dma_result(reqp, bytes_left));
1049 }
1050 
1051 extern __inline__ int
1052 can_access_5380()
1053 {
1054 	if (machineid & ATARI_FALCON)
1055 		return(falcon_can_access_5380());
1056 	return(1);
1057 }
1058 
1059 #define emulated_dma()		((machineid & ATARI_HADES) ? 1 : 0)
1060 
1061 /*
1062  * Locking stuff. All turns into NOP's on the TT.
1063  */
1064 #define	fair_to_keep_dma()	((machineid & ATARI_FALCON) ?		\
1065 						!st_dmawanted() : 1)
1066 #define	claimed_dma()		((machineid & ATARI_FALCON) ?		\
1067 						falcon_claimed_dma() : 1)
1068 #define reconsider_dma()	{					\
1069 					if(machineid & ATARI_FALCON)	\
1070 						falcon_reconsider_dma();\
1071 				}
1072 #endif /* defined(TT_SCSI) && defined(FALCON_SCSI) */
1073 
1074 /**********************************************
1075  * Functions present for both TT and Falcon.  *
1076  **********************************************/
1077 /*
1078  * Our autoconfig matching function
1079  */
1080 static int
1081 machine_match(struct device *pdp, void *match, void *auxp,
1082 						struct cfdriver *cd)
1083 {
1084 	struct cfdata *cdp = match;
1085 
1086 	if (strcmp(auxp, cd->cd_name))
1087 		return(0);
1088 	if (cdp->cf_unit != 0)	/* Only one unit	*/
1089 		return(0);
1090 	return(1);
1091 }
1092 
1093 /*
1094  * Bounce buffer (de)allocation. Those buffers are gotten from the ST-mem
1095  * pool. Allocation here is both contiguous and in the lower 16Mb of
1096  * the address space. Thus being DMA-able for all controllers.
1097  */
1098 static u_char *
1099 alloc_bounceb(u_long len)
1100 {
1101 	void	*tmp;
1102 
1103 	return((u_char *)alloc_stmem(len, &tmp));
1104 }
1105 
1106 static void
1107 free_bounceb(u_char *bounceb)
1108 {
1109 	free_stmem(bounceb);
1110 }
1111 
1112 /*
1113  * 5380 interrupt.
1114  */
1115 void
1116 scsi_ctrl(int sr)
1117 {
1118 	if (GET_5380_REG(NCR5380_DMSTAT) & SC_IRQ_SET) {
1119 		scsi_idisable();
1120 		if (!BASEPRI(sr))
1121 			add_sicallback((si_farg)ncr_ctrl_intr,
1122 						(void *)cur_softc, 0);
1123 		else {
1124 			spl1();
1125 			ncr_ctrl_intr(cur_softc);
1126 			spl0();
1127 		}
1128 	}
1129 }
1130 
1131 /*
1132  * DMA controller interrupt
1133  */
1134 void
1135 scsi_dma(int sr)
1136 {
1137 	SC_REQ	*reqp;
1138 
1139 	if ((reqp = connected) && (reqp->dr_flag & DRIVER_IN_DMA)) {
1140 		scsi_idisable();
1141 		if (!BASEPRI(sr))
1142 			add_sicallback((si_farg)ncr_dma_intr,
1143 					(void *)cur_softc, 0);
1144 		else {
1145 			spl1();
1146 			ncr_dma_intr(cur_softc);
1147 			spl0();
1148 		}
1149 	}
1150 }
1151 
1152 /*
1153  * Last but not least... Include the general driver code
1154  */
1155 #include <atari/dev/ncr5380.c>
1156