xref: /netbsd-src/sys/arch/amiga/dev/efa.c (revision 23e63c4b5cecc703250c97faac1ad970f4954821)
1 /*	$NetBSD: efa.c,v 1.17 2023/12/20 00:40:42 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Radoslaw Kujawa.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Driver for FastATA 1200 EIDE controller, manufactured by ELBOX Computer.
34  *
35  * Gayle-related stuff inspired by wdc_amiga.c written by Michael L. Hitch
36  * and Aymeric Vincent.
37  */
38 
39 #include <sys/cdefs.h>
40 
41 #include <sys/types.h>
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/device.h>
45 #include <sys/bus.h>
46 #include <sys/proc.h>
47 #include <sys/kernel.h>
48 #include <sys/kthread.h>
49 
50 #include <machine/cpu.h>
51 #include <machine/intr.h>
52 #include <sys/bswap.h>
53 
54 #include <amiga/amiga/cia.h>
55 #include <amiga/amiga/custom.h>
56 #include <amiga/amiga/device.h>
57 #include <amiga/amiga/gayle.h>
58 #include <amiga/dev/zbusvar.h>
59 
60 #include <dev/ata/atavar.h>
61 #include <dev/ic/wdcvar.h>
62 
63 #include <amiga/dev/efareg.h>
64 #include <amiga/dev/efavar.h>
65 
66 #define EFA_32BIT_IO 1
67 /* #define EFA_NO_INTR 1 */
68 /* #define EFA_DEBUG 1 */
69 
70 int		efa_probe(device_t, cfdata_t, void *);
71 void		efa_attach(device_t, device_t, void *);
72 int		efa_intr(void *);
73 int		efa_intr_soft(void *arg);
74 static void	efa_set_opts(struct efa_softc *sc);
75 static bool	efa_mapbase(struct efa_softc *sc);
76 static bool	efa_mapreg_gayle(struct efa_softc *sc);
77 static bool	efa_mapreg_native(struct efa_softc *sc);
78 static void	efa_fata_subregion_pio0(struct wdc_regs *wdr_fata);
79 static void	efa_fata_subregion_pion(struct wdc_regs *wdr_fata, bool data32);
80 static void	efa_setup_channel(struct ata_channel *chp);
81 static void	efa_attach_channel(struct efa_softc *sc, int i);
82 static void	efa_select_regset(struct efa_softc *sc, int chnum,
83 		    uint8_t piomode);
84 static void	efa_poll_kthread(void *arg);
85 static bool	efa_compare_status(void);
86 #ifdef EFA_DEBUG
87 static void	efa_debug_print_regmapping(struct wdc_regs *wdr_fata);
88 #endif /* EFA_DEBUG */
89 
90 CFATTACH_DECL_NEW(efa, sizeof(struct efa_softc),
91     efa_probe, efa_attach, NULL, NULL);
92 
93 #define PIO_NSUPP		0xFFFFFFFF
94 
95 static const bus_addr_t		pio_offsets[] =
96     { FATA1_PIO0_OFF, PIO_NSUPP, PIO_NSUPP, FATA1_PIO3_OFF, FATA1_PIO4_OFF,
97       FATA1_PIO5_OFF };
98 static const unsigned int	wdr_offsets_pio0[] =
99     { FATA1_PIO0_OFF_DATA, FATA1_PIO0_OFF_ERROR, FATA1_PIO0_OFF_SECCNT,
100       FATA1_PIO0_OFF_SECTOR, FATA1_PIO0_OFF_CYL_LO, FATA1_PIO0_OFF_CYL_HI,
101       FATA1_PIO0_OFF_SDH, FATA1_PIO0_OFF_COMMAND };
102 static const unsigned int	wdr_offsets_pion[] =
103     { FATA1_PION_OFF_DATA, FATA1_PION_OFF_ERROR, FATA1_PION_OFF_SECCNT,
104       FATA1_PION_OFF_SECTOR, FATA1_PION_OFF_CYL_LO, FATA1_PION_OFF_CYL_HI,
105       FATA1_PION_OFF_SDH, FATA1_PION_OFF_COMMAND };
106 
107 int
efa_probe(device_t parent,cfdata_t cfp,void * aux)108 efa_probe(device_t parent, cfdata_t cfp, void *aux)
109 {
110 	/*
111 	 * FastATA 1200 uses portions of Gayle IDE interface, and efa driver
112 	 * can't coexist with wdc_amiga. Match "wdc" on an A1200, because
113 	 * FastATA 1200 does not autoconfigure.
114 	 */
115 	if (!matchname(aux, "wdc") || !is_a1200())
116 		return(0);
117 
118 	if (!efa_compare_status())
119 		return(0);
120 
121 #ifdef EFA_DEBUG
122 	aprint_normal("efa_probe succeeded\n");
123 #endif /* EFA_DEBUG */
124 
125 	return 100;
126 }
127 
128 void
efa_attach(device_t parent,device_t self,void * aux)129 efa_attach(device_t parent, device_t self, void *aux)
130 {
131 	int i;
132 	struct efa_softc *sc = device_private(self);
133 
134 	aprint_normal(": ELBOX FastATA 1200\n");
135 
136 	gayle_init();
137 
138 	efa_set_opts(sc);
139 
140 	if (!efa_mapbase(sc)) {
141 		aprint_error_dev(self, "couldn't map base addresses\n");
142 		return;
143 	}
144 	if (!efa_mapreg_gayle(sc)) {
145 		aprint_error_dev(self, "couldn't map Gayle registers\n");
146 		return;
147 	}
148 	if (!efa_mapreg_native(sc)) {
149 		aprint_error_dev(self, "couldn't map FastATA registers\n");
150 		return;
151 	}
152 
153 	sc->sc_wdcdev.sc_atac.atac_pio_cap = 5;
154 	sc->sc_wdcdev.sc_atac.atac_nchannels = FATA1_CHANNELS;
155 	sc->sc_wdcdev.sc_atac.atac_set_modes = efa_setup_channel;
156 	sc->sc_wdcdev.sc_atac.atac_dev = self;
157 	sc->sc_wdcdev.sc_atac.atac_channels = sc->sc_chanlist;
158 	sc->sc_wdcdev.sc_atac.atac_cap = ATAC_CAP_DATA16;
159 	sc->sc_wdcdev.wdc_maxdrives = 2;
160 
161 	if (sc->sc_32bit_io)
162 		sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_DATA32;
163 
164 	/*
165 	 * The following should work for polling mode, but it does not.
166 	 * if (sc->sc_no_intr)
167 	 *	sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_NOIRQ;
168 	 */
169 
170 	wdc_allocate_regs(&sc->sc_wdcdev);
171 
172 	for (i = 0; i < FATA1_CHANNELS; i++)
173 		efa_attach_channel(sc, i);
174 
175 	if (sc->sc_no_intr) {
176 		sc->sc_fata_softintr = softint_establish(SOFTINT_BIO,
177 		    (void (*)(void *))efa_intr_soft, sc);
178 		if (sc->sc_fata_softintr == NULL) {
179 			aprint_error_dev(self, "couldn't create soft intr\n");
180 			return;
181 		}
182 		if (kthread_create(PRI_NONE, 0, NULL, efa_poll_kthread, sc,
183 		    NULL, "efa")) {
184 			aprint_error_dev(self, "couldn't create kthread\n");
185 			return;
186 		}
187 	} else {
188 		sc->sc_isr.isr_intr = efa_intr;
189 		sc->sc_isr.isr_arg = sc;
190 		sc->sc_isr.isr_ipl = 2;
191 		add_isr (&sc->sc_isr);
192 		gayle_intr_enable_set(GAYLE_INT_IDE);
193 	}
194 
195 }
196 
197 static void
efa_attach_channel(struct efa_softc * sc,int chnum)198 efa_attach_channel(struct efa_softc *sc, int chnum)
199 {
200 #ifdef EFA_DEBUG
201 	device_t self;
202 
203 	self = sc->sc_wdcdev.sc_atac.atac_dev;
204 #endif /* EFA_DEBUG */
205 
206 	sc->sc_chanlist[chnum] = &sc->sc_ports[chnum].chan;
207 
208 	sc->sc_ports[chnum].chan.ch_channel = chnum;
209 	sc->sc_ports[chnum].chan.ch_atac = &sc->sc_wdcdev.sc_atac;
210 
211 	if (!sc->sc_32bit_io)
212 		efa_select_regset(sc, chnum, 0); /* Start in PIO0. */
213 	else
214 		efa_select_regset(sc, chnum, 3);
215 
216 	wdc_init_shadow_regs(CHAN_TO_WDC_REGS(&sc->sc_ports[chnum].chan));
217 
218 	wdcattach(&sc->sc_ports[chnum].chan);
219 
220 #ifdef EFA_DEBUG
221 	aprint_normal_dev(self, "done init for channel %d\n", chnum);
222 #endif
223 
224 }
225 
226 /* TODO: convert to callout(9) */
227 static void
efa_poll_kthread(void * arg)228 efa_poll_kthread(void *arg)
229 {
230 	struct efa_softc *sc = arg;
231 
232 	for (;;) {
233 		/* TODO: actually check if interrupt status register is set */
234 		softint_schedule(sc->sc_fata_softintr);
235 		/* TODO: convert to kpause */
236 		tsleep(arg, PWAIT, "efa_poll", hz);
237 	}
238 }
239 
240 static void
efa_set_opts(struct efa_softc * sc)241 efa_set_opts(struct efa_softc *sc)
242 {
243 	device_t self;
244 
245 	self = sc->sc_wdcdev.sc_atac.atac_dev;
246 
247 #ifdef EFA_32BIT_IO
248 	sc->sc_32bit_io = true;
249 #else
250 	sc->sc_32bit_io = false;
251 #endif /* EFA_32BIT_IO */
252 
253 #ifdef EFA_NO_INTR
254 	sc->sc_no_intr = true;		/* XXX: not yet! */
255 #else
256 	sc->sc_no_intr = false;
257 #endif /* EFA_NO_INTR */
258 
259 	if (sc->sc_no_intr)
260 		aprint_verbose_dev(self, "hardware interrupt disabled\n");
261 
262 	if (sc->sc_32bit_io)
263 		aprint_verbose_dev(self, "32-bit I/O enabled\n");
264 }
265 
266 int
efa_intr_soft(void * arg)267 efa_intr_soft(void *arg)
268 {
269 	int ret = 0;
270 	struct efa_softc *sc = (struct efa_softc *)arg;
271 
272 	/* TODO: check which channel needs servicing */
273 	/*
274 	uint8_t fataintreq;
275 	fataintreq = bus_space_read_1(sc->sc_ports[0].wdr[piom].cmd_iot,
276 	sc->sc_ports[chnum].intst[piom], 0);
277 	*/
278 
279 	ret = wdcintr(&sc->sc_ports[0].chan);
280 	ret = wdcintr(&sc->sc_ports[1].chan);
281 
282 	return ret;
283 }
284 
285 int
efa_intr(void * arg)286 efa_intr(void *arg)
287 {
288 	struct efa_softc *sc = (struct efa_softc *)arg;
289 	int r1, r2, ret;
290 	uint8_t intreq;
291 
292 	intreq = gayle_intr_status();
293 	ret = 0;
294 
295 	if (intreq & GAYLE_INT_IDE) {
296 		gayle_intr_ack(0x7C | (intreq & 0x03));
297 		/* How to check which channel caused interrupt?
298 		 * Interrupt status register is not very useful here. */
299 		r1 = wdcintr(&sc->sc_ports[0].chan);
300 		r2 = wdcintr(&sc->sc_ports[1].chan);
301 		ret = r1 | r2;
302 	}
303 
304 	return ret;
305 }
306 
307 static bool
efa_mapbase(struct efa_softc * sc)308 efa_mapbase(struct efa_softc *sc)
309 {
310 	static struct bus_space_tag fata_cmd_iot;
311 	static struct bus_space_tag gayle_cmd_iot;
312 	int i, j;
313 #ifdef EFA_DEBUG
314 	device_t self;
315 
316 	self = sc->sc_wdcdev.sc_atac.atac_dev;
317 #endif /* EFA_DEBUG */
318 
319 	gayle_cmd_iot.base = (bus_addr_t) ztwomap(GAYLE_IDE_BASE + 2);
320 	gayle_cmd_iot.absm = &amiga_bus_stride_4swap;
321 	fata_cmd_iot.base = (bus_addr_t) ztwomap(FATA1_BASE);
322 	fata_cmd_iot.absm = &amiga_bus_stride_4swap;
323 
324 #ifdef EFA_DEBUG
325 	aprint_normal_dev(self, "Gayle %x -> %x, FastATA %x -> %x\n",
326 	    GAYLE_IDE_BASE, gayle_cmd_iot.base, FATA1_BASE, fata_cmd_iot.base);
327 #endif
328 
329 	if (!gayle_cmd_iot.base)
330 		return false;
331 	if (!fata_cmd_iot.base)
332 		return false;
333 
334 	sc->sc_gayle_wdc_regs.cmd_iot = &gayle_cmd_iot;
335 	sc->sc_gayle_wdc_regs.ctl_iot = &gayle_cmd_iot;
336 
337 	for (i = 0; i < FATA1_CHANNELS; i++) {
338 		for (j = 0; j < PIO_COUNT; j++) {
339 			sc->sc_ports[i].wdr[j].cmd_iot = &fata_cmd_iot;
340 			sc->sc_ports[i].wdr[j].data32iot = &fata_cmd_iot;
341 			sc->sc_ports[i].wdr[j].ctl_iot = &gayle_cmd_iot;
342 		}
343 	}
344 
345 	return true;
346 }
347 
348 
349 /* Gayle IDE register mapping, we need it anyway. */
350 static bool
efa_mapreg_gayle(struct efa_softc * sc)351 efa_mapreg_gayle(struct efa_softc *sc)
352 {
353 	int i;
354 
355 	struct wdc_regs *wdr = &sc->sc_gayle_wdc_regs;
356 
357 	if (bus_space_map(wdr->cmd_iot, 0, 0x40, 0,
358 	    &wdr->cmd_baseioh)) {
359 		return false;
360 	}
361 
362 	for (i = 0; i < WDC_NREG; i++) {
363 		if (bus_space_subregion(wdr->cmd_iot,
364 		    wdr->cmd_baseioh, i, i == 0 ? 4 : 1,
365 		    &wdr->cmd_iohs[i]) != 0) {
366 
367 			bus_space_unmap(wdr->cmd_iot,
368 			    wdr->cmd_baseioh, 0x40);
369 			return false;
370 		}
371 	}
372 
373 	if (bus_space_subregion(wdr->cmd_iot,
374 	    wdr->cmd_baseioh, 0x406, 1, &wdr->ctl_ioh))
375 		return false;
376 
377 	return true;
378 }
379 
380 /* Native FastATA register mapping, suitable for PIO modes 0 to 5. */
381 static bool
efa_mapreg_native(struct efa_softc * sc)382 efa_mapreg_native(struct efa_softc *sc)
383 {
384 	struct wdc_regs *wdr_gayle = &sc->sc_gayle_wdc_regs;
385 	struct wdc_regs *wdr_fata;
386 	int i,j;
387 #ifdef EFA_DEBUG
388 	device_t self;
389 
390 	self = sc->sc_wdcdev.sc_atac.atac_dev;
391 #endif /* EFA_DEBUG */
392 
393 	for (i = 0; i < FATA1_CHANNELS; i++) {
394 
395 		for (j = 0; j < PIO_COUNT; j++) {
396 
397 			wdr_fata = &sc->sc_ports[i].wdr[j];
398 			sc->sc_ports[i].mode_ok[j] = false;
399 
400 			if (pio_offsets[j] == PIO_NSUPP) {
401 #ifdef EFA_DEBUG
402 				aprint_normal_dev(self,
403 				    "Skipping mapping for PIO mode %x\n", j);
404 #endif
405 				continue;
406 			}
407 
408 			if (bus_space_map(wdr_fata->cmd_iot,
409 			    pio_offsets[j] + FATA1_CHAN_SIZE * i,
410 			    FATA1_CHAN_SIZE, 0, &wdr_fata->cmd_baseioh)) {
411 			    return false;
412 			}
413 #ifdef EFA_DEBUG
414 			aprint_normal_dev(self,
415 			    "Chan %x PIO mode %x mapped %x -> %x\n",
416 			    i, j, (bus_addr_t) kvtop((void*)
417 			    wdr_fata->cmd_baseioh), (unsigned int)
418 			    wdr_fata->cmd_baseioh);
419 #endif
420 
421 			sc->sc_ports[i].mode_ok[j] = true;
422 
423 			if (j == 0)
424 				efa_fata_subregion_pio0(wdr_fata);
425 			else {
426 				if (sc->sc_32bit_io)
427 					efa_fata_subregion_pion(wdr_fata,
428 					    true);
429 				else
430 					efa_fata_subregion_pion(wdr_fata,
431 					    false);
432 
433 				bus_space_subregion(wdr_fata->cmd_iot,
434 				    wdr_fata->cmd_baseioh, FATA1_PION_OFF_INTST,
435 				    1, &sc->sc_ports[i].intst[j]);
436 			}
437 
438 			/* No 32-bit register for PIO0 ... */
439 			if (j == 0 && sc->sc_32bit_io)
440 				sc->sc_ports[i].mode_ok[j] = false;
441 
442 			wdr_fata->ctl_ioh = wdr_gayle->ctl_ioh;
443 		};
444 	}
445 	return true;
446 }
447 
448 
449 static void
efa_fata_subregion_pio0(struct wdc_regs * wdr_fata)450 efa_fata_subregion_pio0(struct wdc_regs *wdr_fata)
451 {
452 	int i;
453 
454 	for (i = 0; i < WDC_NREG; i++)
455 		bus_space_subregion(wdr_fata->cmd_iot,
456 		    wdr_fata->cmd_baseioh, wdr_offsets_pio0[i],
457 		    i == 0 ? 4 : 1, &wdr_fata->cmd_iohs[i]);
458 }
459 
460 static void
efa_fata_subregion_pion(struct wdc_regs * wdr_fata,bool data32)461 efa_fata_subregion_pion(struct wdc_regs *wdr_fata, bool data32)
462 {
463 	int i;
464 
465 	if (data32)
466 		bus_space_subregion(wdr_fata->cmd_iot, wdr_fata->cmd_baseioh,
467 		    FATA1_PION_OFF_DATA32, 8, &wdr_fata->data32ioh);
468 
469 	for (i = 0; i < WDC_NREG; i++)
470 		bus_space_subregion(wdr_fata->cmd_iot,
471 		    wdr_fata->cmd_baseioh, wdr_offsets_pion[i],
472 		    i == 0 ? 4 : 1, &wdr_fata->cmd_iohs[i]);
473 }
474 
475 static void
efa_setup_channel(struct ata_channel * chp)476 efa_setup_channel(struct ata_channel *chp)
477 {
478 	int drive, chnum;
479 	uint8_t mode;
480 	struct atac_softc *atac;
481 	struct ata_drive_datas *drvp;
482 	struct efa_softc *sc;
483 	int ipl;
484 #ifdef EFA_DEBUG
485 	device_t self;
486 #endif /* EFA_DEBUG */
487 
488 	chnum = chp->ch_channel;
489 	atac = chp->ch_atac;
490 
491 	sc = device_private(atac->atac_dev);
492 
493 	mode = 5; /* start with fastest possible setting */
494 
495 #ifdef EFA_DEBUG
496 	self = sc->sc_wdcdev.sc_atac.atac_dev;
497 	aprint_normal_dev(self, "efa_setup_channel for ch %d\n",
498 	    chnum);
499 #endif /* EFA_DEBUG */
500 
501 	/* We might be in the middle of something... so raise IPL. */
502 	ipl = splvm();
503 
504 	for (drive = 0; drive < 2; drive++) {
505 		drvp = &chp->ch_drive[drive];
506 
507 		if (drvp->drive_type == ATA_DRIVET_NONE)
508 			continue; /* nothing to see here */
509 
510 		if (drvp->PIO_cap < mode)
511 			mode = drvp->PIO_cap;
512 
513 		/* TODO: check if sc_ports->mode_ok */
514 
515 #ifdef EFA_DEBUG
516 		aprint_normal_dev(self, "drive %d supports %d\n",
517 		    drive, drvp->PIO_cap);
518 #endif /* EFA_DEBUG */
519 
520 		drvp->PIO_mode = mode;
521 	}
522 
523 	/* Change FastATA register set. */
524 	efa_select_regset(sc, chnum, mode);
525 	/* re-init shadow regs */
526 	wdc_init_shadow_regs(CHAN_TO_WDC_REGS(&sc->sc_ports[chnum].chan));
527 
528 	splx(ipl);
529 }
530 
531 static void
efa_select_regset(struct efa_softc * sc,int chnum,uint8_t piomode)532 efa_select_regset(struct efa_softc *sc, int chnum, uint8_t piomode)
533 {
534 	struct wdc_softc *wdc;
535 #ifdef EFA_DEBUG
536 	device_t self;
537 
538 	self = sc->sc_wdcdev.sc_atac.atac_dev;
539 #endif /* EFA_DEBUG */
540 
541 	wdc = CHAN_TO_WDC(&sc->sc_ports[chnum].chan);
542 	wdc->regs[chnum] = sc->sc_ports[chnum].wdr[piomode];
543 
544 #ifdef EFA_DEBUG
545 	aprint_normal_dev(self, "switched ch %d to PIO %d\n",
546 	    chnum, piomode);
547 
548 	efa_debug_print_regmapping(&wdc->regs[chnum]);
549 #endif /* EFA_DEBUG */
550 }
551 
552 #ifdef EFA_DEBUG
553 static void
efa_debug_print_regmapping(struct wdc_regs * wdr_fata)554 efa_debug_print_regmapping(struct wdc_regs *wdr_fata)
555 {
556 	int i;
557 	aprint_normal("base %x->%x",
558 	    (bus_addr_t) kvtop((void*) wdr_fata->cmd_baseioh),
559 	    (bus_addr_t) wdr_fata->cmd_baseioh);
560 	for (i = 0; i < WDC_NREG; i++) {
561 		aprint_normal("reg %x, %x->%x, ", i,
562 		    (bus_addr_t) kvtop((void*) wdr_fata->cmd_iohs[i]),
563 		    (bus_addr_t) wdr_fata->cmd_iohs[i]);
564 	}
565 	aprint_normal("\n");
566 }
567 #endif /* EFA_DEBUG */
568 
569 /* Compare the values of (status) command register in PIO0, PIO3 sets. */
570 static bool
efa_compare_status(void)571 efa_compare_status(void)
572 {
573 	uint8_t cmd0, cmd3;
574 	struct bus_space_tag fata_bst;
575 	bus_space_tag_t fata_iot;
576 	bus_space_handle_t cmd0_ioh, cmd3_ioh;
577 	bool rv;
578 
579 	rv = false;
580 
581 	fata_bst.base = (bus_addr_t) ztwomap(FATA1_BASE);
582 	fata_bst.absm = &amiga_bus_stride_4swap;
583 
584 	fata_iot = &fata_bst;
585 
586 	if (bus_space_map(fata_iot, pio_offsets[0], FATA1_CHAN_SIZE, 0,
587 	    &cmd0_ioh))
588 		return false;
589 	if (bus_space_map(fata_iot, pio_offsets[3], FATA1_CHAN_SIZE, 0,
590 	    &cmd3_ioh))
591 		return false;
592 
593 #ifdef EFA_DEBUG
594 	aprint_normal("probing for FastATA at %x, %x: ", (bus_addr_t) cmd0_ioh,
595 	    (bus_addr_t) cmd3_ioh);
596 #endif /* EFA_DEBUG */
597 
598 	cmd0 = bus_space_read_1(fata_iot, cmd0_ioh, FATA1_PIO0_OFF_COMMAND);
599 	cmd3 = bus_space_read_1(fata_iot, cmd3_ioh, FATA1_PION_OFF_COMMAND);
600 
601 	if (cmd0 == cmd3)
602 		rv = true;
603 
604 	if ( (cmd0 == 0xFF) || (cmd0 == 0x00) ) {
605 		/* Assume there's nothing there... */
606 		rv = false;
607 	}
608 
609 #ifdef EFA_DEBUG
610 	aprint_normal("cmd0 %x, cmd3 %x\n", cmd0, cmd3);
611 #endif /* EFA_DEBUG */
612 
613 	bus_space_unmap(fata_iot, pio_offsets[0], FATA1_CHAN_SIZE);
614 	bus_space_unmap(fata_iot, pio_offsets[3], FATA1_CHAN_SIZE);
615 
616 	return rv;
617 }
618 
619