xref: /illumos-gate/usr/src/uts/common/io/i8237A.c (revision 7c478bd9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
28 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
29 /*	  All Rights Reserved  	*/
30 
31 /*	Copyright (c) 1988, 1989 Intel Corp.			*/
32 /*	All Rights Reserved	*/
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"
35 
36 /*
37  * Set features for each architecture.  List of features:
38  *	ADDR_32:	Address is 32 bits
39  *	COUNT_24:	Count is 24 bits
40  *	DMA_4CSCD:	DMA channel 4 is used for cascade of channels 0-3)
41  *	DMA_INTR:	DMA interrupt is available (always with DMA_BUF_CHAIN)
42  *	DMA_BUF_CHAIN:	DMA buffer chaining is available (always with DMA_INTR)
43  *	MEM_TO_MEM:	Memory to memory transfers available
44  *	NO_PROG_WIDTH:	Channel data width is NOT programmable
45  *	SCATER_GATHER	Scatter-gather DMA is available (code not implemented)
46  *	ISA_MODE	Standard ISA modes available
47  *	EISA_EXT_MODE:	EISA extension modes available
48  */
49 
50 /*
51  * Address is 24 bits (default) with no carry between lo word and hi byte
52  * Count is 16 bits (default)
53  */
54 #define	DMA_4CSCD
55 #define	NO_PROG_WIDTH
56 #define	ISA_MODE
57 
58 #include <sys/types.h>
59 #include <sys/cpuvar.h>
60 #include <sys/disp.h>
61 #include <sys/sunddi.h>
62 #include <sys/cmn_err.h>
63 #include <sys/dma_engine.h>
64 #include <sys/dma_i8237A.h>
65 
66 #if defined(DEBUG)
67 #include <sys/promif.h>
68 static int i8237debug = 0;
69 #define	dprintf(x)	if (i8237debug) (void)prom_printf x
70 #else
71 #define	dprintf(x)
72 #endif	/* defined(DEBUG) */
73 
74 
75 extern int EISA_chaining;
76 
77 /*
78  * data structures for maintaining the DMACs
79  */
80 static kmutex_t dma_engine_lock;
81 static struct d37A_chan_reg_addr chan_addr[] = { D37A_BASE_REGS_VALUES };
82 static ushort_t d37A_chnl_path[] = {
83 	DMAE_PATH_8,	/* first 4 DMA channels default to 8-bit xfers */
84 	DMAE_PATH_8,
85 	DMAE_PATH_8,
86 	DMAE_PATH_8,
87 	0,
88 	DMAE_PATH_16,	/* last 3 DMA channels default to 16-bit xfers */
89 	DMAE_PATH_16,
90 	DMAE_PATH_16};
91 static ushort_t d37A_chnl_mode[] = {
92 	DMAE_TRANS_SNGL, DMAE_TRANS_SNGL, DMAE_TRANS_SNGL, DMAE_TRANS_SNGL,
93 #ifdef DMA_4CSCD
94 	DMAE_TRANS_CSCD,
95 #else 	/* !DMA_4CSCD */
96 	DMAE_TRANS_SNGL,
97 #endif	/* !DMA_4CSCD */
98 	DMAE_TRANS_SNGL, DMAE_TRANS_SNGL, DMAE_TRANS_SNGL};
99 #ifdef DMA_BUF_CHAIN
100 static ddi_dma_cookie_t *d37A_next_cookie[] =
101 	{0, 0, 0, 0, 0, 0, 0, 0};
102 #endif	/* DMA_BUF_CHAIN */
103 
104 
105 #ifdef DMA_INTR
106 static uint_t d37A_intr(caddr_t);
107 #endif
108 static int d37A_set_mode(struct ddi_dmae_req *, int);
109 static int d37A_write_addr(ulong_t, int);
110 static ulong_t d37A_read_addr(int);
111 static int d37A_write_count(long, int);
112 static long d37A_read_count(int);
113 
114 #ifdef DMA_BUF_CHAIN
115 static void dEISA_setchain(ddi_dma_cookie_t *cp, int chnl);
116 #endif
117 
118 /*
119  *  Routine: d37A_init()
120  *  purpose: initializes the 8237A.
121  *  caller:  dma_init()
122  *  calls:   d37A macros, d37A_init()
123  */
124 
125 /*ARGSUSED*/
126 int
127 d37A_init(dev_info_t *dip)
128 {
129 #ifdef DMA_INTR
130 	ddi_iblock_cookie_t iblk_cookie = 0;
131 	int	error;
132 
133 	if ((error = ddi_add_intr(dip, (uint_t)0, &iblk_cookie,
134 	    (ddi_idevice_cookie_t *)0, d37A_intr, (caddr_t)NULL)) !=
135 	    DDI_SUCCESS) {
136 		if (error != DDI_INTR_NOTFOUND)
137 			cmn_err(CE_WARN, "!d37A_init: cannot add dma intr\n");
138 		EISA_chaining = 0;
139 	}
140 	mutex_init(&dma_engine_lock, NULL, MUTEX_DRIVER, (void *)iblk_cookie);
141 #else	/* !DMA_INTR */
142 	mutex_init(&dma_engine_lock, NULL, MUTEX_DRIVER, NULL);
143 #endif	/* !DMA_INTR */
144 
145 	return (DDI_SUCCESS);
146 }
147 
148 /*
149  *  Routine: d37A_valid()
150  *  purpose: validates the channel to be acquired.
151  *  caller:  i_dmae_acquire()
152  *  calls:
153  */
154 
155 int
156 d37A_dma_valid(int chnl)
157 {
158 #ifdef DMA_4CSCD
159 	if (chnl == 4)
160 		return (0);
161 #endif	/* DMA_4CSCD */
162 	return (1);
163 }
164 
165 /*
166  *  Routine: d37A_release()
167  *  purpose: resets the 8237A mode.
168  *  caller:  i_dmae_free()
169  *  calls:
170  */
171 
172 void
173 d37A_dma_release(int chnl)
174 {
175 #ifdef DMA_4CSCD
176 	if (chnl == 4)
177 		return;
178 #endif	/* DMA_4CSCD */
179 	d37A_chnl_mode[chnl] = DMAE_TRANS_SNGL;
180 }
181 
182 /*
183  *  routine: d37A_dma_disable()
184  *  purpose: Prevent the DMAC from responding to external hardware
185  *		requests for DMA service on the given channel
186  *  caller:  dma_disable()
187  *  calls:   d37A macros
188  */
189 void
190 d37A_dma_disable(int chnl)
191 {
192 	dprintf(("d37A_dma_disable: chnl=%d mask_reg=0x%x\n",
193 	    chnl, chan_addr[chnl].mask_reg));
194 
195 	outb(chan_addr[chnl].mask_reg, (chnl & 3) | DMA_SETMSK);
196 }
197 
198 
199 /*
200  *  routine: d37A_dma_enable()
201  *  purpose: Enable to DMAC to respond to hardware requests for DMA
202  *		service on the specified channel.
203  *  caller:  dma_enable()
204  *  calls:   d37A macros
205  */
206 
207 void
208 d37A_dma_enable(int chnl)
209 {
210 	dprintf(("d37A_dma_enable: chnl=%d mask_reg=0x%x val=0x%x\n",
211 	    chnl, chan_addr[chnl].mask_reg, chnl & 3));
212 
213 /*	mutex_enter(&dma_engine_lock);	*/
214 	outb(chan_addr[chnl].mask_reg, chnl & 3);
215 /*	mutex_exit(&dma_engine_lock);	*/
216 }
217 
218 
219 /*
220  *  routine: d37A_get_best_mode()
221  *  purpose: stub routine - determine optimum transfer method
222  *  caller:  dma_get_best_mode().
223  *  calls:
224  */
225 /* ARGSUSED */
226 uchar_t
227 d37A_get_best_mode(struct ddi_dmae_req *dmaereqp)
228 {
229 	return (DMAE_CYCLES_2);
230 }
231 
232 #ifdef DMA_INTR
233 /*
234  *  routine: d37A_intr()
235  *  purpose: stub routine
236  *  caller:
237  *  calls:  dma_intr().
238  */
239 /*ARGSUSED*/
240 static uint_t
241 d37A_intr(caddr_t arg)
242 {
243 	int chnl, istate, nstate;
244 	uint_t mask;
245 
246 	if ((istate = (inb(EISA_DMAIS) & 0xef)) != 0) {
247 		/* channel 4 can't interrupt */
248 		chnl = 0;
249 		nstate = istate;
250 		mutex_enter(&dma_engine_lock);
251 		do {
252 			if (istate & 1) {
253 				dEISA_setchain(d37A_next_cookie[chnl], chnl);
254 #ifdef DEBUG
255 				if (chnl < 4)
256 					mask = inb(DMAC1_ALLMASK) >> (chnl);
257 				else
258 					mask = inb(DMAC2_ALLMASK) >> (chnl - 4);
259 				if (mask & 1)
260 prom_printf("eisa: dma buffer chaining failure chnl %d!\n", chnl);
261 
262 #endif	/* DEBUG */
263 			}
264 			chnl++;
265 			istate >>= 1;
266 		} while (istate);
267 		chnl = 0;
268 		do {
269 			if ((nstate & 1) && d37A_next_cookie[chnl])
270 				d37A_next_cookie[chnl] = _dmae_nxcookie(chnl);
271 			chnl++;
272 			nstate >>= 1;
273 		} while (nstate);
274 		mutex_exit(&dma_engine_lock);
275 		return (DDI_INTR_CLAIMED);
276 	}
277 	return (DDI_INTR_UNCLAIMED);
278 }
279 #endif	/* DMA_INTR */
280 
281 
282 #ifdef DMA_BUF_CHAIN
283 /*
284  *  routine: dEISA_setchain()
285  *  purpose: Set next buffer address/count from chain
286  *  caller:  d37A_intr()
287  *  calls:   d37A macros
288  */
289 static void
290 dEISA_setchain(ddi_dma_cookie_t *cp, int chnl)
291 {
292 	if (cp) {
293 		dprintf(("dEISA_setchain: chnl=%d next_addr=%x count=%lx\n",
294 		    chnl, cp->dmac_address, cp->dmac_size));
295 		(void) d37A_write_addr(cp->dmac_address, chnl);
296 		(void) d37A_write_count(cp->dmac_size, chnl);
297 		outb(chan_addr[chnl].scm_reg, chnl | EISA_ENCM | EISA_CMOK);
298 	} else {
299 		/*
300 		 *  clear chain enable bit
301 		 */
302 		outb(chan_addr[chnl].scm_reg, chnl);
303 		dprintf(("dEISA_setchain: chnl=%d end\n", chnl));
304 	}
305 }
306 #endif	/* DMA_BUF_CHAIN */
307 
308 
309 /*
310  *  routine: d37A_prog_chan()
311  *  purpose: program the Mode registers and the Base registers of a
312  *		DMA channel for a subsequent hardware-initiated transfer.
313  *  caller:  dma_prog_chan()
314  *  calls:   d37A_write_addr(), d37A_write_count(), d37A macros.
315  */
316 
317 int
318 d37A_prog_chan(struct ddi_dmae_req *dmaereqp, ddi_dma_cookie_t *cp, int chnl)
319 {
320 	if (d37A_chnl_mode[chnl] == DMAE_TRANS_CSCD) {
321 		dprintf(("d37A_prog_chan err: chnl=%d in cascade mode\n",
322 		    chnl));
323 		return (DDI_FAILURE);
324 	}
325 #ifndef MEM_TO_MEM
326 	if (dmaereqp && dmaereqp->der_dest == DMAE_DEST_MEM) {
327 dprintf(("d37A_prog_chan err: memory to memory mode not supported.\n"));
328 		return (DDI_FAILURE);
329 	}
330 #endif	/* !MEM_TO_MEM */
331 
332 	dprintf(("d37A_prog_chan: chnl=%d dmaereq=%p\n",
333 	    chnl, (void *)dmaereqp));
334 
335 	if (dmaereqp) {
336 		switch (chnl) {
337 		case DMAE_CH0:
338 		case DMAE_CH1:
339 		case DMAE_CH2:
340 		case DMAE_CH3:
341 #ifdef NO_PROG_WIDTH
342 			if (dmaereqp->der_path &&
343 			    dmaereqp->der_path != DMAE_PATH_8) {
344 dprintf(("d37A_prog_chan err: chnl %d not programmed.\n", chnl));
345 				return (DDI_FAILURE);
346 			}
347 #endif	/* NO_PROG_WIDTH */
348 			break;
349 
350 #ifndef DMA_4CSCD
351 		case DMAE_CH4:
352 #endif	/* !DMA_4CSCD */
353 		case DMAE_CH5:
354 		case DMAE_CH6:
355 		case DMAE_CH7:
356 #ifdef NO_PROG_WIDTH
357 			if (dmaereqp->der_path &&
358 			    dmaereqp->der_path != DMAE_PATH_16) {
359 dprintf(("d37A_prog_chan err: chnl %d not programmed.\n", chnl));
360 				return (DDI_FAILURE);
361 			}
362 #endif	/* NO_PROG_WIDTH */
363 			break;
364 
365 		default:
366 dprintf(("d37A_prog_chan err: chnl %d not programmed.\n", chnl));
367 			return (DDI_FAILURE);
368 		}
369 	} else
370 		chnl &= 3;
371 	mutex_enter(&dma_engine_lock);
372 
373 	d37A_dma_disable(chnl);
374 	if (dmaereqp)
375 		(void) d37A_set_mode(dmaereqp, chnl);
376 
377 	if (cp) {
378 		(void) d37A_write_addr(cp->dmac_address, chnl);
379 		(void) d37A_write_count(cp->dmac_size, chnl);
380 
381 #ifdef DMA_BUF_CHAIN
382 		if (dmaereqp && dmaereqp->der_bufprocess == DMAE_BUF_CHAIN &&
383 		    (d37A_next_cookie[chnl] = _dmae_nxcookie(chnl))) {
384 			/*
385 			 * i/o operation has more than 1 cookie
386 			 * so enable dma buffer chaining
387 			 */
388 			drv_usecwait(10);
389 			outb(chan_addr[chnl].scm_reg, chnl | EISA_ENCM);
390 			drv_usecwait(15);
391 			dEISA_setchain(d37A_next_cookie[chnl], chnl);
392 			d37A_next_cookie[chnl] = _dmae_nxcookie(chnl);
393 		}
394 #endif	/* DMA_BUF_CHAIN */
395 	}
396 	mutex_exit(&dma_engine_lock);
397 	return (DDI_SUCCESS);
398 }
399 
400 
401 /*
402  *  routine: d37A_dma_swsetup()
403  *  purpose: program the Mode registers and the Base register for the
404  *		specified channel.
405  *  caller:  dma_swsetup()
406  *  calls:   d37A_write_addr(), d37A_write_count(), d37A macros.
407  */
408 
409 int
410 d37A_dma_swsetup(struct ddi_dmae_req *dmaereqp, ddi_dma_cookie_t *cp, int chnl)
411 {
412 	if (d37A_chnl_mode[chnl] == DMAE_TRANS_CSCD) {
413 		dprintf(("d37A_dma_swsetup err: chnl %d not programmed\n",
414 		    chnl));
415 		return (DDI_FAILURE);
416 	}
417 
418 	dprintf(("d37A_dma_swsetup: chnl=%d dmaereq=%p.\n",
419 	    chnl, (void *)dmaereqp));
420 
421 	/* MUST BE IN BLOCK MODE FOR SOFTWARE INITIATED REQUESTS */
422 	if (dmaereqp->der_trans != DMAE_TRANS_BLCK)
423 		dmaereqp->der_trans = DMAE_TRANS_BLCK;
424 
425 	switch (chnl) {
426 	case DMAE_CH0:
427 	case DMAE_CH1:
428 	case DMAE_CH2:
429 	case DMAE_CH3:
430 #ifdef NO_PROG_WIDTH
431 		if (dmaereqp->der_path && dmaereqp->der_path != DMAE_PATH_8) {
432 dprintf(("d37A_dma_swsetup err: chnl %d not programmed.\n", chnl));
433 			return (DDI_FAILURE);
434 		}
435 #endif	/* NO_PROG_WIDTH */
436 		break;
437 
438 #ifndef DMA_4CSCD
439 	case DMAE_CH4:
440 #endif	/* !DMA_4CSCD */
441 	case DMAE_CH5:
442 	case DMAE_CH6:
443 	case DMAE_CH7:
444 #ifdef NO_PROG_WIDTH
445 		if (dmaereqp->der_path && dmaereqp->der_path != DMAE_PATH_16) {
446 dprintf(("d37A_dma_swsetup err: chnl %d not programmed.\n", chnl));
447 			return (DDI_FAILURE);
448 		}
449 #endif	/* NO_PROG_WIDTH */
450 		break;
451 
452 	default:
453 		dprintf(("d37A_dma_swsetup err: chnl %d not set up.\n", chnl));
454 		return (DDI_FAILURE);
455 	};
456 
457 	mutex_enter(&dma_engine_lock);
458 
459 	d37A_dma_disable(chnl);
460 	(void) d37A_set_mode(dmaereqp, chnl);
461 
462 	(void) d37A_write_addr(cp->dmac_address, chnl);
463 	(void) d37A_write_count(cp->dmac_size, chnl);
464 
465 #ifdef DMA_BUF_CHAIN
466 	if (dmaereqp->der_bufprocess == DMAE_BUF_CHAIN &&
467 	    (d37A_next_cookie[chnl] = _dmae_nxcookie(chnl))) {
468 		/*
469 		 * i/o operation has more than 1 cookie
470 		 * so enable dma buffer chaining
471 		 */
472 		outb(chan_addr[chnl].scm_reg, chnl | EISA_ENCM);
473 		dEISA_setchain(d37A_next_cookie[chnl], chnl);
474 		d37A_next_cookie[chnl] = _dmae_nxcookie(chnl);
475 	}
476 #endif	/* DMA_BUF_CHAIN */
477 	mutex_exit(&dma_engine_lock);
478 	return (DDI_SUCCESS);
479 }
480 
481 
482 /*
483  *  routine: d37A_dma_swstart()
484  *  purpose: SW start transfer setup on the indicated channel.
485  *  caller:  dma_swstart()
486  *  calls:   d37A_dma_enable(), d37A macros
487  */
488 
489 void
490 d37A_dma_swstart(int chnl)
491 {
492 	dprintf(("d37A_dma_swstart: chnl=%d\n", chnl));
493 
494 	mutex_enter(&dma_engine_lock);
495 	d37A_dma_enable(chnl);
496 	outb(chan_addr[chnl].reqt_reg, DMA_SETMSK | chnl); /* set request bit */
497 	mutex_exit(&dma_engine_lock);
498 }
499 
500 
501 /*
502  *  routine: d37A_dma_stop()
503  *  purpose: Stop any activity on the indicated channel.
504  *  caller:  dma_stop()
505  *  calls:   d37A macros
506  */
507 
508 void
509 d37A_dma_stop(int chnl)
510 {
511 	dprintf(("d37A_dma_stop: chnl=%d\n", chnl));
512 
513 	mutex_enter(&dma_engine_lock);
514 	d37A_dma_disable(chnl);
515 	outb(chan_addr[chnl].reqt_reg, chnl & 3);    /* reset request bit */
516 	mutex_exit(&dma_engine_lock);
517 }
518 
519 
520 /*
521  *  routine: d37A_get_chan_stat()
522  *  purpose: retrieve the Current Address and Count registers for the
523  *		specified channel.
524  *  caller:  dma_get_chan_stat()
525  *  calls:   d37A_read_addr(), d37A_read_count().
526  */
527 void
528 d37A_get_chan_stat(int chnl, ulong_t *addressp, int *countp)
529 {
530 	ulong_t taddr;
531 	int tcount;
532 
533 	mutex_enter(&dma_engine_lock);
534 	taddr = d37A_read_addr(chnl);
535 	tcount = d37A_read_count(chnl);
536 	mutex_exit(&dma_engine_lock);
537 	if (addressp)
538 		*addressp = taddr;
539 	if (countp)
540 		*countp = tcount;
541 	dprintf(("d37A_get_chan_stat: chnl=%d address=%lx count=%x\n",
542 	    chnl, taddr, tcount));
543 }
544 
545 
546 /*
547  *  routine: d37A_set_mode()
548  *  purpose: program the Mode registers of the
549  *		DMAC for a subsequent hardware-initiated transfer.
550  *  caller:  d37A_prog_chan(), d37A_dma_swsetup
551  *  calls:
552  */
553 
554 static int
555 d37A_set_mode(struct ddi_dmae_req *dmaereqp, int chnl)
556 {
557 	uchar_t mode = 0, emode = 0;
558 
559 #ifdef ISA_MODE
560 #if defined(lint)
561 	emode = emode;
562 #endif
563 	mode = chnl & 3;
564 
565 	switch (dmaereqp->der_command) {
566 	case DMAE_CMD_READ:
567 		mode |= DMAMODE_READ;
568 		break;
569 	case DMAE_CMD_WRITE:
570 		mode |= DMAMODE_WRITE;
571 		break;
572 	case DMAE_CMD_VRFY:
573 		mode |= DMAMODE_VERF;
574 		break;
575 	case DMAE_CMD_TRAN:
576 		mode |= 0x0C;	/* for Adaptec 1st party DMA on chnl 0 */
577 		break;
578 	default:
579 		return (DDI_FAILURE);
580 	}
581 
582 	if (dmaereqp->der_bufprocess == DMAE_BUF_AUTO)
583 		mode |= DMAMODE_AUTO;
584 
585 	if (dmaereqp->der_step == DMAE_STEP_DEC)
586 		mode |= DMAMODE_DECR;
587 
588 	switch (dmaereqp->der_trans) {
589 	case DMAE_TRANS_SNGL:
590 		mode |= DMAMODE_SINGLE;
591 		break;
592 	case DMAE_TRANS_BLCK:
593 		mode |= DMAMODE_BLOCK;
594 		break;
595 	case DMAE_TRANS_DMND:
596 		break;
597 	case DMAE_TRANS_CSCD:
598 		mode |= DMAMODE_CASC;
599 		break;
600 	default:
601 		return (DDI_FAILURE);
602 	}
603 	d37A_chnl_mode[chnl] = dmaereqp->der_trans;
604 
605 	dprintf(("d37A_set_mode: chnl=%d mode_reg=0x%x mode=0x%x\n",
606 	    chnl, chan_addr[chnl].mode_reg, mode));
607 	outb(chan_addr[chnl].mode_reg, mode);
608 #endif	/* ISA_MODE */
609 
610 #ifdef EISA_EXT_MODE
611 	emode = chnl & 3;
612 	d37A_chnl_path[chnl] = dmaereqp->der_path;
613 
614 	switch (dmaereqp->der_path) {
615 	case DMAE_PATH_8:
616 		/* emode |= EISA_DMA_8; */
617 		break;
618 	case DMAE_PATH_16:
619 		emode |= EISA_DMA_16;
620 		break;
621 	case DMAE_PATH_32:
622 		emode |= EISA_DMA_32;
623 		break;
624 	case DMAE_PATH_16B:
625 		emode |= EISA_DMA_16B;
626 		break;
627 	default:
628 		switch (chnl) {
629 		case DMAE_CH0:
630 		case DMAE_CH1:
631 		case DMAE_CH2:
632 		case DMAE_CH3:
633 			d37A_chnl_path[chnl] = DMAE_PATH_8;
634 			/* emode |= EISA_DMA_8; */
635 			break;
636 		case DMAE_CH5:
637 		case DMAE_CH6:
638 		case DMAE_CH7:
639 			d37A_chnl_path[chnl] = DMAE_PATH_16;
640 			emode |= EISA_DMA_16;
641 			break;
642 		}
643 	}
644 	emode |= (dmaereqp->der_cycles & 3) << 4;
645 	outb(chan_addr[chnl].emode_reg, emode);
646 
647 	dprintf(("d37A_set_mode: chnl=%d em_reg=0x%x emode=0x%x\n",
648 	    chnl, chan_addr[chnl].emode_reg, emode));
649 #endif	/* EISA_EXT_MODE */
650 	return (DDI_SUCCESS);
651 }
652 
653 
654 /*
655  *  routine: d37A_write_addr()
656  *  purpose: write the 24- or 32-bit physical address into the Base Address
657  *		Register for the indicated channel.
658  *  caller:  d37A_prog_chan(), d37A_dma_swsetup().
659  *  calls:   d37A macros
660  */
661 
662 static int
663 d37A_write_addr(ulong_t paddress, int chnl)
664 {
665 	uchar_t *adr_byte;
666 
667 	dprintf(("d37A_write_addr: chnl=%d address=%lx\n", chnl, paddress));
668 
669 	switch (d37A_chnl_path[chnl]) {
670 	case DMAE_PATH_8:
671 	case DMAE_PATH_16B:
672 	case DMAE_PATH_32:
673 		/*
674 		 * program DMA controller with byte address
675 		 */
676 		break;
677 
678 	case DMAE_PATH_16:
679 		/*
680 		 * convert byte address to shifted word address
681 		 */
682 		paddress = (paddress & ~0x1ffff) | ((paddress & 0x1ffff) >> 1);
683 		break;
684 
685 	default:
686 		return (DDI_FAILURE);
687 	}
688 	kpreempt_disable();	/* don't preempt thread while using flip-flop */
689 	outb(chan_addr[chnl].ff_reg, 0);	/* set flipflop */
690 
691 	adr_byte = (uchar_t *)&paddress;
692 	outb(chan_addr[chnl].addr_reg, adr_byte[0]);
693 	outb(chan_addr[chnl].addr_reg, adr_byte[1]);
694 	outb(chan_addr[chnl].page_reg, adr_byte[2]);
695 #ifdef ADDR_32
696 	outb(chan_addr[chnl].hpage_reg, adr_byte[3]);
697 #endif	/* ADDR_32 */
698 
699 	kpreempt_enable();
700 	return (DDI_SUCCESS);
701 }
702 
703 
704 /*
705  *  routine: d37A_read_addr()
706  *  purpose: read the 24- or 32-bit physical address from the Current Address
707  *		Register for the indicated channel.
708  *  caller:  d37A_get_chan_stat().
709  *  calls:   d37A macros
710  */
711 
712 static ulong_t
713 d37A_read_addr(int chnl)
714 {
715 	ulong_t paddress = 0;
716 	uchar_t *adr_byte;
717 
718 	kpreempt_disable();	/* don't preempt thread while using flip-flop */
719 	adr_byte = (uchar_t *)&paddress;
720 	outb(chan_addr[chnl].ff_reg, 0);	/* set flipflop */
721 
722 	adr_byte[0] = inb(chan_addr[chnl].addr_reg);
723 	adr_byte[1] = inb(chan_addr[chnl].addr_reg);
724 	adr_byte[2] = inb(chan_addr[chnl].page_reg);
725 #ifdef ADDR_32
726 	adr_byte[3] = inb(chan_addr[chnl].hpage_reg);
727 #endif	/* ADDR_32 */
728 
729 	kpreempt_enable();
730 
731 	switch (d37A_chnl_path[chnl]) {
732 	case DMAE_PATH_8:
733 	case DMAE_PATH_16B:
734 	case DMAE_PATH_32:
735 		/*
736 		 * return with byte address
737 		 */
738 		break;
739 
740 	case DMAE_PATH_16:
741 		/*
742 		 * convert shifted word address to byte address
743 		 */
744 		paddress = (paddress & ~0x1ffff) | ((paddress & 0x0ffff) << 1);
745 		break;
746 
747 	default:
748 		return ((ulong_t)DDI_FAILURE);
749 	}
750 
751 	dprintf(("d37A_read_addr: chnl=%d address=%lx.\n", chnl, paddress));
752 	return (paddress);
753 }
754 
755 
756 /*
757  *  routine: d37A_write_count()
758  *  purpose: write the 16- or 24-bit count into the Base Count Register for
759  *		the indicated channel.
760  *  caller:  d37A_prog_chan(), d37A_dma_swsetup()
761  *  calls:   d37A macros
762  */
763 
764 static int
765 d37A_write_count(long count, int chnl)
766 {
767 	uchar_t *count_byte;
768 
769 	dprintf(("d37A_write_count: chnl=%d count=0x%lx\n", chnl, count));
770 
771 	switch (d37A_chnl_path[chnl]) {
772 	case DMAE_PATH_16:
773 		/*
774 		 * Convert byte count to word count
775 		 */
776 		count >>= 1;
777 		/* FALLTHROUGH */
778 	case DMAE_PATH_8:
779 	case DMAE_PATH_16B:
780 	case DMAE_PATH_32:
781 		--count;
782 		break;
783 
784 	default:
785 		return (DDI_FAILURE);
786 	}
787 
788 	kpreempt_disable();	/* don't preempt thread while using flip-flop */
789 	outb(chan_addr[chnl].ff_reg, 0);	/* set flipflop */
790 
791 	count_byte = (uchar_t *)&count;
792 	outb(chan_addr[chnl].cnt_reg, count_byte[0]);
793 	outb(chan_addr[chnl].cnt_reg, count_byte[1]);
794 #ifdef COUNT_24
795 	outb(chan_addr[chnl].hcnt_reg, count_byte[2]);
796 #endif	/* COUNT_24 */
797 
798 	kpreempt_enable();
799 	return (DDI_SUCCESS);
800 }
801 
802 
803 /*
804  *  routine: d37A_read_count()
805  *  purpose: read the 16- or 24-bit count from the Current Count Register for
806  *		the indicated channel
807  *  caller:  d37A_get_chan_stat()
808  *  calls:   d37A macros
809  */
810 
811 static long
812 d37A_read_count(int chnl)
813 {
814 	long count = 0;
815 	uchar_t *count_byte;
816 
817 	kpreempt_disable();	/* don't preempt thread while using flip-flop */
818 	count_byte = (uchar_t *)&count;
819 	outb(chan_addr[chnl].ff_reg, 0);	/* set flipflop */
820 
821 	count_byte[0] = inb(chan_addr[chnl].cnt_reg);
822 	count_byte[1] = inb(chan_addr[chnl].cnt_reg);
823 #ifdef COUNT_24
824 	count_byte[2] = inb(chan_addr[chnl].hcnt_reg);
825 #endif	/* COUNT_24 */
826 
827 #ifdef COUNT_24
828 	if ((ulong_t)count == 0xffffff)
829 #else	/* !COUNT_24 */
830 	if ((ulong_t)count == 0xffff)
831 #endif	/* !COUNT_24 */
832 		count = -1;
833 
834 	kpreempt_enable();
835 
836 	switch (d37A_chnl_path[chnl]) {
837 	case DMAE_PATH_8:
838 	case DMAE_PATH_16B:
839 	case DMAE_PATH_32:
840 		++count;
841 		break;
842 
843 	case DMAE_PATH_16:
844 		/*
845 		 * Convert incremented word count to byte count
846 		 */
847 		count = (count + 1) << 1;
848 		break;
849 	}
850 	dprintf(("d37A_read_count: chnl=%d count=0x%lx\n", chnl, count));
851 	return (count);
852 }
853