xref: /netbsd-src/sys/dev/pci/pcscp.c (revision 2a15d9a398ae09d011bcb975f730615e2c316690)
1 /*	$NetBSD: pcscp.c,v 1.50 2023/05/17 18:20:30 tsutsui Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center; Izumi Tsutsui.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * pcscp.c: device dependent code for AMD Am53c974 (PCscsi-PCI)
35  * written by Izumi Tsutsui <tsutsui@NetBSD.org>
36  *
37  * Technical manual available at
38  * https://www.amd.com/system/files/TechDocs/19113.pdf
39  */
40 
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: pcscp.c,v 1.50 2023/05/17 18:20:30 tsutsui Exp $");
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/device.h>
47 #include <sys/buf.h>
48 
49 #include <sys/bus.h>
50 #include <sys/intr.h>
51 
52 #include <dev/scsipi/scsipi_all.h>
53 #include <dev/scsipi/scsi_all.h>
54 #include <dev/scsipi/scsiconf.h>
55 
56 #include <dev/pci/pcireg.h>
57 #include <dev/pci/pcivar.h>
58 #include <dev/pci/pcidevs.h>
59 
60 #include <dev/ic/ncr53c9xreg.h>
61 #include <dev/ic/ncr53c9xvar.h>
62 
63 #include <dev/pci/pcscpreg.h>
64 
65 #define IO_MAP_REG	0x10
66 
67 struct pcscp_softc {
68 	struct ncr53c9x_softc sc_ncr53c9x;	/* glue to MI code */
69 
70 	bus_space_tag_t sc_st;		/* bus space tag */
71 	bus_space_handle_t sc_sh;	/* bus space handle */
72 	void *sc_ih;			/* interrupt cookie */
73 
74 	bus_dma_tag_t sc_dmat;		/* DMA tag */
75 
76 	bus_dmamap_t sc_xfermap;	/* DMA map for transfers */
77 
78 	uint32_t *sc_mdladdr;		/* MDL array */
79 	bus_dmamap_t sc_mdldmap;	/* MDL DMA map */
80 
81 	int	sc_active;		/* DMA state */
82 	int	sc_datain;		/* DMA Data Direction */
83 	size_t	sc_dmasize;		/* DMA size */
84 	uint8_t	**sc_dmaaddr;		/* DMA address */
85 	size_t	*sc_dmalen;		/* DMA length */
86 };
87 
88 #define	READ_DMAREG(sc, reg) \
89 	bus_space_read_4((sc)->sc_st, (sc)->sc_sh, (reg))
90 #define	WRITE_DMAREG(sc, reg, var) \
91 	bus_space_write_4((sc)->sc_st, (sc)->sc_sh, (reg), (var))
92 
93 #define	PCSCP_READ_REG(sc, reg)	\
94 	bus_space_read_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2)
95 #define	PCSCP_WRITE_REG(sc, reg, val)	\
96 	bus_space_write_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2, (val))
97 
98 
99 static int pcscp_match(device_t, cfdata_t, void *);
100 static void pcscp_attach(device_t, device_t, void *);
101 
102 CFATTACH_DECL_NEW(pcscp, sizeof(struct pcscp_softc),
103     pcscp_match, pcscp_attach, NULL, NULL);
104 
105 /*
106  * Functions and the switch for the MI code.
107  */
108 
109 static uint8_t	pcscp_read_reg(struct ncr53c9x_softc *, int);
110 static void	pcscp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
111 static int	pcscp_dma_isintr(struct ncr53c9x_softc *);
112 static void	pcscp_dma_reset(struct ncr53c9x_softc *);
113 static int	pcscp_dma_intr(struct ncr53c9x_softc *);
114 static int	pcscp_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *,
115 		    int, size_t *);
116 static void	pcscp_dma_go(struct ncr53c9x_softc *);
117 static void	pcscp_dma_stop(struct ncr53c9x_softc *);
118 static int	pcscp_dma_isactive(struct ncr53c9x_softc *);
119 
120 static struct ncr53c9x_glue pcscp_glue = {
121 	pcscp_read_reg,
122 	pcscp_write_reg,
123 	pcscp_dma_isintr,
124 	pcscp_dma_reset,
125 	pcscp_dma_intr,
126 	pcscp_dma_setup,
127 	pcscp_dma_go,
128 	pcscp_dma_stop,
129 	pcscp_dma_isactive,
130 	NULL,			/* gl_clear_latched_intr */
131 };
132 
133 static int
pcscp_match(device_t parent,cfdata_t cf,void * aux)134 pcscp_match(device_t parent, cfdata_t cf, void *aux)
135 {
136 	struct pci_attach_args *pa = aux;
137 
138 	if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_AMD)
139 		return 0;
140 
141 	switch (PCI_PRODUCT(pa->pa_id)) {
142 	case PCI_PRODUCT_AMD_PCSCSI_PCI:
143 		return 1;
144 	}
145 	return 0;
146 }
147 
148 /*
149  * Attach this instance, and then all the sub-devices
150  */
151 static void
pcscp_attach(device_t parent,device_t self,void * aux)152 pcscp_attach(device_t parent, device_t self, void *aux)
153 {
154 	struct pcscp_softc *esc = device_private(self);
155 	struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
156 	struct pci_attach_args *pa = aux;
157 	bus_space_tag_t iot;
158 	bus_space_handle_t ioh;
159 	pci_intr_handle_t ih;
160 	const char *intrstr;
161 	pcireg_t csr;
162 	bus_dma_segment_t seg;
163 	int error, rseg;
164 	char intrbuf[PCI_INTRSTR_LEN];
165 
166 	sc->sc_dev = self;
167 	pci_aprint_devinfo(pa, NULL);
168 	aprint_normal("%s", device_xname(sc->sc_dev));
169 
170 	if (pci_mapreg_map(pa, IO_MAP_REG, PCI_MAPREG_TYPE_IO, 0,
171 	    &iot, &ioh, NULL, NULL)) {
172 		aprint_error(": unable to map registers\n");
173 		return;
174 	}
175 
176 	sc->sc_glue = &pcscp_glue;
177 
178 	esc->sc_st = iot;
179 	esc->sc_sh = ioh;
180 	esc->sc_dmat = pa->pa_dmat;
181 
182 	csr = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG);
183 	pci_conf_write(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG,
184 	    csr | PCI_COMMAND_MASTER_ENABLE | PCI_COMMAND_IO_ENABLE);
185 
186 	/*
187 	 * XXX More of this should be in ncr53c9x_attach(), but
188 	 * XXX should we really poke around the chip that much in
189 	 * XXX the MI code?  Think about this more...
190 	 */
191 
192 	/*
193 	 * Set up static configuration info.
194 	 */
195 
196 	/*
197 	 * XXX should read configuration from EEPROM?
198 	 *
199 	 * MI ncr53c9x driver does not support configuration
200 	 * per each target device, though...
201 	 */
202 	sc->sc_id = 7;
203 	sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
204 	sc->sc_cfg2 = NCRCFG2_SCSI2 | NCRCFG2_FE;
205 	sc->sc_cfg3 = NCRAMDCFG3_IDM | NCRAMDCFG3_FCLK;
206 	sc->sc_cfg4 = NCRAMDCFG4_GE12NS | NCRAMDCFG4_RADE;
207 	sc->sc_rev = NCR_VARIANT_AM53C974;
208 	sc->sc_features = NCR_F_FASTSCSI;
209 	sc->sc_cfg3_fscsi = NCRAMDCFG3_FSCSI;
210 	sc->sc_freq = 40; /* MHz */
211 
212 	/*
213 	 * XXX minsync and maxxfer _should_ be set up in MI code,
214 	 * XXX but it appears to have some dependency on what sort
215 	 * XXX of DMA we're hooked up to, etc.
216 	 */
217 
218 	/*
219 	 * This is the value used to start sync negotiations
220 	 * Note that the NCR register "SYNCTP" is programmed
221 	 * in "clocks per byte", and has a minimum value of 4.
222 	 * The SCSI period used in negotiation is one-fourth
223 	 * of the time (in nanoseconds) needed to transfer one byte.
224 	 * Since the chip's clock is given in MHz, we have the following
225 	 * formula: 4 * period = (1000 / freq) * 4
226 	 */
227 
228 	sc->sc_minsync = 1000 / sc->sc_freq;
229 
230 	/* Really no limit, but since we want to fit into the TCR... */
231 	sc->sc_maxxfer = 16 * 1024 * 1024;
232 
233 	/*
234 	 * Create the DMA maps for the data transfers.
235 	 */
236 
237 #define MDL_SEG_SIZE	0x1000 /* 4kbyte per segment */
238 #define MDL_SEG_OFFSET	0x0FFF
239 #define MDL_SIZE	(MAXPHYS / MDL_SEG_SIZE + 1) /* no hardware limit? */
240 
241 	if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MDL_SEG_SIZE,
242 	    MDL_SEG_SIZE, BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
243 		aprint_error(": can't create DMA maps\n");
244 		return;
245 	}
246 
247 	/*
248 	 * Allocate and map memory for the MDL.
249 	 */
250 
251 	if ((error = bus_dmamem_alloc(esc->sc_dmat,
252 	    sizeof(uint32_t) * MDL_SIZE, PAGE_SIZE, 0, &seg, 1, &rseg,
253 	    BUS_DMA_NOWAIT)) != 0) {
254 		aprint_error(": unable to allocate memory for the MDL,"
255 		    " error = %d\n", error);
256 		goto fail_0;
257 	}
258 	if ((error = bus_dmamem_map(esc->sc_dmat, &seg, rseg,
259 	    sizeof(uint32_t) * MDL_SIZE , (void **)&esc->sc_mdladdr,
260 	    BUS_DMA_NOWAIT|BUS_DMA_COHERENT)) != 0) {
261 		aprint_error(": unable to map the MDL memory, error = %d\n",
262 		    error);
263 		goto fail_1;
264 	}
265 	if ((error = bus_dmamap_create(esc->sc_dmat,
266 	    sizeof(uint32_t) * MDL_SIZE, 1, sizeof(uint32_t) * MDL_SIZE,
267 	    0, BUS_DMA_NOWAIT, &esc->sc_mdldmap)) != 0) {
268 		aprint_error(": unable to map_create for the MDL, error = %d\n",
269 		    error);
270 		goto fail_2;
271 	}
272 	if ((error = bus_dmamap_load(esc->sc_dmat, esc->sc_mdldmap,
273 	     esc->sc_mdladdr, sizeof(uint32_t) * MDL_SIZE,
274 	     NULL, BUS_DMA_NOWAIT)) != 0) {
275 		aprint_error(": unable to load for the MDL, error = %d\n",
276 		    error);
277 		goto fail_3;
278 	}
279 
280 	/* map and establish interrupt */
281 	if (pci_intr_map(pa, &ih)) {
282 		aprint_error(": couldn't map interrupt\n");
283 		goto fail_4;
284 	}
285 
286 	intrstr = pci_intr_string(pa->pa_pc, ih, intrbuf, sizeof(intrbuf));
287 	esc->sc_ih = pci_intr_establish_xname(pa->pa_pc, ih, IPL_BIO,
288 	    ncr53c9x_intr, esc, device_xname(self));
289 	if (esc->sc_ih == NULL) {
290 		aprint_error(": couldn't establish interrupt");
291 		if (intrstr != NULL)
292 			aprint_error(" at %s", intrstr);
293 		aprint_error("\n");
294 		goto fail_4;
295 	}
296 	if (intrstr != NULL) {
297 		aprint_normal(": interrupting at %s\n", intrstr);
298 		aprint_normal("%s", device_xname(sc->sc_dev));
299 	}
300 
301 	/* Do the common parts of attachment. */
302 	sc->sc_adapter.adapt_minphys = minphys;
303 	sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
304 	ncr53c9x_attach(sc);
305 
306 	/* Turn on target selection using the `DMA' method */
307 	sc->sc_features |= NCR_F_DMASELECT;
308 
309 	return;
310 
311  fail_4:
312 	bus_dmamap_unload(esc->sc_dmat, esc->sc_mdldmap);
313  fail_3:
314 	bus_dmamap_destroy(esc->sc_dmat, esc->sc_mdldmap);
315  fail_2:
316 	bus_dmamem_unmap(esc->sc_dmat, (void *)esc->sc_mdldmap,
317 	    sizeof(uint32_t) * MDL_SIZE);
318  fail_1:
319 	bus_dmamem_free(esc->sc_dmat, &seg, rseg);
320  fail_0:
321 	bus_dmamap_destroy(esc->sc_dmat, esc->sc_xfermap);
322 }
323 
324 /*
325  * Glue functions.
326  */
327 
328 static uint8_t
pcscp_read_reg(struct ncr53c9x_softc * sc,int reg)329 pcscp_read_reg(struct ncr53c9x_softc *sc, int reg)
330 {
331 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
332 
333 	return PCSCP_READ_REG(esc, reg);
334 }
335 
336 static void
pcscp_write_reg(struct ncr53c9x_softc * sc,int reg,uint8_t v)337 pcscp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t v)
338 {
339 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
340 
341 	PCSCP_WRITE_REG(esc, reg, v);
342 }
343 
344 static int
pcscp_dma_isintr(struct ncr53c9x_softc * sc)345 pcscp_dma_isintr(struct ncr53c9x_softc *sc)
346 {
347 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
348 
349 	return (PCSCP_READ_REG(esc, NCR_STAT) & NCRSTAT_INT) != 0;
350 }
351 
352 static void
pcscp_dma_reset(struct ncr53c9x_softc * sc)353 pcscp_dma_reset(struct ncr53c9x_softc *sc)
354 {
355 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
356 
357 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE);
358 
359 	esc->sc_active = 0;
360 }
361 
362 static int
pcscp_dma_intr(struct ncr53c9x_softc * sc)363 pcscp_dma_intr(struct ncr53c9x_softc *sc)
364 {
365 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
366 	int trans, resid, i;
367 	bus_dmamap_t dmap = esc->sc_xfermap;
368 	int datain = esc->sc_datain;
369 	uint32_t dmastat;
370 	uint8_t *p = NULL;
371 
372 	dmastat = READ_DMAREG(esc, DMA_STAT);
373 
374 	if (dmastat & DMASTAT_ERR) {
375 		/* XXX not tested... */
376 		WRITE_DMAREG(esc, DMA_CMD,
377 		    DMACMD_ABORT | (datain ? DMACMD_DIR : 0));
378 
379 		printf("%s: error: DMA error detected; Aborting.\n",
380 		    device_xname(sc->sc_dev));
381 		bus_dmamap_unload(esc->sc_dmat, dmap);
382 		return -1;
383 	}
384 
385 	if (dmastat & DMASTAT_ABT) {
386 		/* XXX What should be done? */
387 		printf("%s: %s: DMA aborted.\n",
388 		    device_xname(sc->sc_dev), __func__);
389 		WRITE_DMAREG(esc, DMA_CMD,
390 		    DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
391 		esc->sc_active = 0;
392 		return 0;
393 	}
394 
395 #ifdef DIAGNOSTIC
396 	/* This is an "assertion" :) */
397 	if (esc->sc_active == 0)
398 		panic("%s: %s: DMA wasn't active",
399 		    device_xname(sc->sc_dev), __func__);
400 #endif
401 
402 	/* DMA has stopped */
403 
404 	esc->sc_active = 0;
405 
406 	if (esc->sc_dmasize == 0) {
407 		/* A "Transfer Pad" operation completed */
408 		NCR_DMA(("%s: discarded %d bytes (tcl=%d, tcm=%d)\n",
409 		    __func__,
410 		    PCSCP_READ_REG(esc, NCR_TCL) |
411 		    (PCSCP_READ_REG(esc, NCR_TCM) << 8),
412 		    PCSCP_READ_REG(esc, NCR_TCL),
413 		    PCSCP_READ_REG(esc, NCR_TCM)));
414 		return 0;
415 	}
416 
417 	resid = 0;
418 	/*
419 	 * If a transfer onto the SCSI bus gets interrupted by the device
420 	 * (e.g. for a SAVEPOINTER message), the data in the FIFO counts
421 	 * as residual since the ESP counter registers get decremented as
422 	 * bytes are clocked into the FIFO.
423 	 */
424 	if (!datain &&
425 	    (resid = (PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
426 		NCR_DMA(("%s: empty esp FIFO of %d ", __func__, resid));
427 	}
428 
429 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
430 		/*
431 		 * `Terminal count' is off, so read the residue
432 		 * out of the ESP counter registers.
433 		 */
434 		if (datain) {
435 			resid = PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
436 			while (resid > 1)
437 				resid =
438 				    PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
439 			WRITE_DMAREG(esc, DMA_CMD, DMACMD_BLAST | DMACMD_MDL |
440 			    (datain ? DMACMD_DIR : 0));
441 
442 			for (i = 0; i < 1000; i++) { /* XXX */
443 				if (READ_DMAREG(esc, DMA_STAT) & DMASTAT_BCMP)
444 					break;
445 				DELAY(1);
446 			}
447 
448 			/* See the below comments... */
449 			if (resid)
450 				p = *esc->sc_dmaaddr;
451 		}
452 
453 		resid += PCSCP_READ_REG(esc, NCR_TCL) |
454 		    (PCSCP_READ_REG(esc, NCR_TCM) << 8) |
455 		    (PCSCP_READ_REG(esc, NCR_TCH) << 16);
456 	} else {
457 		while ((dmastat & DMASTAT_DONE) == 0)
458 			dmastat = READ_DMAREG(esc, DMA_STAT);
459 	}
460 
461 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
462 
463 	/* sync MDL */
464 	bus_dmamap_sync(esc->sc_dmat, esc->sc_mdldmap,
465 	    0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_POSTWRITE);
466 	/* sync transfer buffer */
467 	bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
468 	    datain ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
469 	bus_dmamap_unload(esc->sc_dmat, dmap);
470 
471 	trans = esc->sc_dmasize - resid;
472 
473 	/*
474 	 * From the technical manual notes:
475 	 *
476 	 * `In some odd byte conditions, one residual byte will be left
477 	 *  in the SCSI FIFO, and the FIFO flags will never count to 0.
478 	 *  When this happens, the residual byte should be retrieved
479 	 *  via PIO following completion of the BLAST operation.'
480 	 */
481 
482 	if (p) {
483 		p += trans;
484 		*p = PCSCP_READ_REG(esc, NCR_FIFO);
485 		trans++;
486 	}
487 
488 	if (trans < 0) {			/* transferred < 0 ? */
489 #if 0
490 		/*
491 		 * This situation can happen in perfectly normal operation
492 		 * if the ESP is reselected while using DMA to select
493 		 * another target.  As such, don't print the warning.
494 		 */
495 		printf("%s: xfer (%d) > req (%d)\n",
496 		    device_xname(sc->sc_dev), trans, esc->sc_dmasize);
497 #endif
498 		trans = esc->sc_dmasize;
499 	}
500 
501 	NCR_DMA(("%s: tcl=%d, tcm=%d, tch=%d; trans=%d, resid=%d\n",
502 	    __func__,
503 	    PCSCP_READ_REG(esc, NCR_TCL),
504 	    PCSCP_READ_REG(esc, NCR_TCM),
505 	    PCSCP_READ_REG(esc, NCR_TCH),
506 	    trans, resid));
507 
508 	*esc->sc_dmalen -= trans;
509 	*esc->sc_dmaaddr += trans;
510 
511 	return 0;
512 }
513 
514 static int
pcscp_dma_setup(struct ncr53c9x_softc * sc,uint8_t ** addr,size_t * len,int datain,size_t * dmasize)515 pcscp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
516     int datain, size_t *dmasize)
517 {
518 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
519 	bus_dmamap_t dmap = esc->sc_xfermap;
520 	uint32_t *mdl;
521 	int error, nseg, seg;
522 	bus_addr_t s_offset, s_addr;
523 
524 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
525 
526 	esc->sc_dmaaddr = addr;
527 	esc->sc_dmalen = len;
528 	esc->sc_dmasize = *dmasize;
529 	esc->sc_datain = datain;
530 
531 #ifdef DIAGNOSTIC
532 	if ((*dmasize / MDL_SEG_SIZE) > MDL_SIZE)
533 		panic("%s: transfer size too large", device_xname(sc->sc_dev));
534 #endif
535 
536 	/*
537 	 * No need to set up DMA in `Transfer Pad' operation.
538 	 * (case of *dmasize == 0)
539 	 */
540 	if (*dmasize == 0)
541 		return 0;
542 
543 	error = bus_dmamap_load(esc->sc_dmat, dmap, *esc->sc_dmaaddr,
544 	    *esc->sc_dmalen, NULL,
545 	    ((sc->sc_nexus->xs->xs_control & XS_CTL_NOSLEEP) ?
546 	    BUS_DMA_NOWAIT : BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
547 	    ((sc->sc_nexus->xs->xs_control & XS_CTL_DATA_IN) ?
548 	     BUS_DMA_READ : BUS_DMA_WRITE));
549 	if (error) {
550 		printf("%s: unable to load dmamap, error = %d\n",
551 		    device_xname(sc->sc_dev), error);
552 		return error;
553 	}
554 
555 	/* set transfer length */
556 	WRITE_DMAREG(esc, DMA_STC, *dmasize);
557 
558 	/* set up MDL */
559 	mdl = esc->sc_mdladdr;
560 	nseg = dmap->dm_nsegs;
561 
562 	/* the first segment is possibly not aligned with 4k MDL boundary */
563 	s_addr = dmap->dm_segs[0].ds_addr;
564 	s_offset = s_addr & MDL_SEG_OFFSET;
565 	s_addr -= s_offset;
566 
567 	/* set the first MDL and offset */
568 	WRITE_DMAREG(esc, DMA_SPA, s_offset);
569 	*mdl++ = htole32(s_addr);
570 
571 	/* the rest dmamap segments are aligned with 4k boundary */
572 	for (seg = 1; seg < nseg; seg++)
573 		*mdl++ = htole32(dmap->dm_segs[seg].ds_addr);
574 
575 	return 0;
576 }
577 
578 static void
pcscp_dma_go(struct ncr53c9x_softc * sc)579 pcscp_dma_go(struct ncr53c9x_softc *sc)
580 {
581 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
582 	bus_dmamap_t dmap = esc->sc_xfermap, mdldmap = esc->sc_mdldmap;
583 	int datain = esc->sc_datain;
584 
585 	/* No DMA transfer in Transfer Pad operation */
586 	if (esc->sc_dmasize == 0)
587 		return;
588 
589 	/* sync transfer buffer */
590 	bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
591 	    datain ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
592 
593 	/* sync MDL */
594 	bus_dmamap_sync(esc->sc_dmat, mdldmap,
595 	    0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_PREWRITE);
596 
597 	/* set Starting MDL Address */
598 	WRITE_DMAREG(esc, DMA_SMDLA, mdldmap->dm_segs[0].ds_addr);
599 
600 	/* set DMA command register bits */
601 	/* XXX DMA Transfer Interrupt Enable bit is broken? */
602 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | DMACMD_MDL |
603 	    /* DMACMD_INTE | */
604 	    (datain ? DMACMD_DIR : 0));
605 
606 	/* issue DMA start command */
607 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_START | DMACMD_MDL |
608 	    /* DMACMD_INTE | */
609 	    (datain ? DMACMD_DIR : 0));
610 
611 	esc->sc_active = 1;
612 }
613 
614 static void
pcscp_dma_stop(struct ncr53c9x_softc * sc)615 pcscp_dma_stop(struct ncr53c9x_softc *sc)
616 {
617 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
618 
619 	/* DMA stop */
620 	/* XXX What should we do here ? */
621 	WRITE_DMAREG(esc, DMA_CMD,
622 	    DMACMD_ABORT | (esc->sc_datain ? DMACMD_DIR : 0));
623 	bus_dmamap_unload(esc->sc_dmat, esc->sc_xfermap);
624 
625 	esc->sc_active = 0;
626 }
627 
628 static int
pcscp_dma_isactive(struct ncr53c9x_softc * sc)629 pcscp_dma_isactive(struct ncr53c9x_softc *sc)
630 {
631 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
632 
633 	/* XXX should check esc->sc_active? */
634 	if ((READ_DMAREG(esc, DMA_CMD) & DMACMD_CMD) != DMACMD_IDLE)
635 		return 1;
636 	return 0;
637 }
638