xref: /netbsd-src/sys/dev/nand/nandemulator.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: nandemulator.c,v 1.7 2015/08/20 14:40:18 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 Department of Software Engineering,
5  *		      University of Szeged, Hungary
6  * Copyright (c) 2011 Adam Hoka <ahoka@NetBSD.org>
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by the Department of Software Engineering, University of Szeged, Hungary
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
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,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: nandemulator.c,v 1.7 2015/08/20 14:40:18 christos Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/device.h>
39 #include <sys/conf.h>
40 #include <sys/kmem.h>
41 #include <sys/kernel.h>
42 
43 #include "nandemulator.h"
44 
45 #include <dev/nand/nand.h>
46 #include <dev/nand/onfi.h>
47 #include <dev/nand/nand_crc.h>
48 
49 #include "ioconf.h"
50 
51 extern struct cfdriver nandemulator_cd;
52 
53 static int nandemulator_match(device_t, cfdata_t, void *);
54 static void nandemulator_attach(device_t, device_t, void *);
55 static int nandemulator_detach(device_t, int);
56 
57 static void nandemulator_device_reset(device_t);
58 static void nandemulator_command(device_t, uint8_t);
59 static void nandemulator_address(device_t, uint8_t);
60 static void nandemulator_busy(device_t);
61 static void nandemulator_read_1(device_t, uint8_t *);
62 static void nandemulator_write_1(device_t, uint8_t);
63 static void nandemulator_read_2(device_t, uint16_t *);
64 static void nandemulator_write_2(device_t, uint16_t);
65 static void nandemulator_read_buf_1(device_t, void *, size_t);
66 static void nandemulator_read_buf_2(device_t, void *, size_t);
67 static void nandemulator_write_buf_1(device_t, const void *, size_t);
68 static void nandemulator_write_buf_2(device_t, const void *, size_t);
69 
70 static size_t nandemulator_address_to_page(device_t);
71 static size_t nandemulator_page_to_backend_offset(device_t, size_t);
72 static size_t nandemulator_column_address_to_subpage(device_t);
73 /*
74 #define NANDEMULATOR_DEBUG 1
75 
76 #ifdef NANDEMULATOR_DEBUG
77 #warning debug enabled
78 #define DPRINTF(x)	if (nandemulatordebug) printf x
79 #define DPRINTFN(n,x)	if (nandemulatordebug>(n)) printf x
80 #else
81 #error no debug
82 #define DPRINTF(x)
83 #define DPRINTFN(n,x)
84 #endif
85 
86 #ifdef NANDEMULATOR_DEBUG
87 int	nandemulatordebug = NANDEMULATOR_DEBUG;
88 #endif
89 */
90 
91 extern int nanddebug;
92 
93 enum {
94 	NANDEMULATOR_8BIT,
95 	NANDEMULATOR_16BIT
96 };
97 
98 struct nandemulator_softc {
99 	device_t		sc_dev;
100 	device_t		sc_nanddev;
101 
102 	int			sc_buswidth;
103 
104 	struct nand_interface	sc_nand_if;
105 
106 	uint8_t			sc_command;
107 	size_t			sc_io_len;
108 	uint8_t			*sc_io_pointer;
109 	uint64_t		sc_address;
110 
111 	uint8_t			*sc_backend;
112 	size_t			sc_backend_size;
113 	size_t			sc_device_size;
114 	bool			sc_register_writable;
115 
116 	uint8_t			sc_status_register;
117 	uint8_t			sc_ids[2];
118 	uint8_t			sc_onfi[4];
119 
120 	size_t			sc_page_size;
121 	size_t			sc_block_size;
122 	size_t			sc_spare_size;
123 	size_t			sc_lun_size;
124 	uint8_t			sc_row_cycles;
125 	uint8_t			sc_column_cycles;
126 	uint64_t		sc_row_mask;
127 
128 	int			sc_address_counter;
129 
130 	struct onfi_parameter_page	*sc_parameter_page;
131 };
132 
133 CFATTACH_DECL_NEW(nandemulator, sizeof(struct nandemulator_softc),
134     nandemulator_match, nandemulator_attach, nandemulator_detach, NULL);
135 
136 void
137 nandemulatorattach(int n)
138 {
139 	int i, err;
140 	cfdata_t cf;
141 
142 	aprint_debug("nandemulator: requested %d units\n", n);
143 
144 	err = config_cfattach_attach(nandemulator_cd.cd_name,
145 	    &nandemulator_ca);
146 	if (err) {
147 		aprint_error("%s: couldn't register cfattach: %d\n",
148 		    nandemulator_cd.cd_name, err);
149 		config_cfdriver_detach(&nandemulator_cd);
150 		return;
151 	}
152 	for (i = 0; i < n; i++) {
153 		cf = kmem_alloc(sizeof(struct cfdata), KM_NOSLEEP);
154 		if (cf == NULL) {
155 			aprint_error("%s: couldn't allocate cfdata\n",
156 			    nandemulator_cd.cd_name);
157 			continue;
158 		}
159 		cf->cf_name = nandemulator_cd.cd_name;
160 		cf->cf_atname = nandemulator_cd.cd_name;
161 		cf->cf_unit = i;
162 		cf->cf_fstate = FSTATE_STAR;
163 
164 		(void)config_attach_pseudo(cf);
165 	}
166 }
167 
168 /* ARGSUSED */
169 static int
170 nandemulator_match(device_t parent, cfdata_t match, void *aux)
171 {
172 	/* pseudo device, always attaches */
173 	return 1;
174 }
175 
176 static void
177 nandemulator_attach(device_t parent, device_t self, void *aux)
178 {
179 	struct nandemulator_softc *sc = device_private(self);
180 	int i;
181 
182 	aprint_normal_dev(self, "NAND emulator\n");
183 
184 	sc->sc_dev = self;
185 
186 	nand_init_interface(&sc->sc_nand_if);
187 
188 	sc->sc_nand_if.command = &nandemulator_command;
189 	sc->sc_nand_if.address = &nandemulator_address;
190 	sc->sc_nand_if.read_buf_1 = &nandemulator_read_buf_1;
191 	sc->sc_nand_if.read_buf_2 = &nandemulator_read_buf_2;
192 	sc->sc_nand_if.read_1 = &nandemulator_read_1;
193 	sc->sc_nand_if.read_2 = &nandemulator_read_2;
194 	sc->sc_nand_if.write_buf_1 = &nandemulator_write_buf_1;
195 	sc->sc_nand_if.write_buf_2 = &nandemulator_write_buf_2;
196 	sc->sc_nand_if.write_1 = &nandemulator_write_1;
197 	sc->sc_nand_if.write_2 = &nandemulator_write_2;
198 	sc->sc_nand_if.busy = &nandemulator_busy;
199 
200 	sc->sc_nand_if.ecc.necc_code_size = 3;
201 	sc->sc_nand_if.ecc.necc_block_size = 256;
202 
203 	if (!pmf_device_register1(sc->sc_dev, NULL, NULL, NULL))
204 		aprint_error_dev(sc->sc_dev,
205 		    "couldn't establish power handler\n");
206 
207 	sc->sc_buswidth = NANDEMULATOR_16BIT;	/* 16bit for now */
208 
209 	/* hardcode these now, make it configurable later */
210 	sc->sc_device_size = 32 * 1024 * 1024; /* 32MB */
211 	sc->sc_page_size = 2048;
212 	sc->sc_block_size = 64;
213 	sc->sc_lun_size =
214 	    sc->sc_device_size / (sc->sc_page_size * sc->sc_block_size);
215 	KASSERT(sc->sc_device_size %
216 	    (sc->sc_page_size * sc->sc_block_size) == 0);
217 	sc->sc_spare_size = 64;
218 
219 	sc->sc_column_cycles = 2;
220 	sc->sc_row_cycles = 3;
221 
222 	/* init the emulator data structures */
223 	sc->sc_backend_size =
224 	    sc->sc_device_size +
225 	    sc->sc_device_size / sc->sc_page_size * sc->sc_spare_size;
226 
227 	sc->sc_backend = kmem_alloc(sc->sc_backend_size, KM_SLEEP);
228 	memset(sc->sc_backend, 0xff, sc->sc_backend_size);
229 
230 	sc->sc_parameter_page =
231 	    kmem_zalloc(sizeof(struct onfi_parameter_page) * 4, KM_SLEEP);
232 
233 	struct onfi_parameter_page *opp;
234 	uint8_t sig[4] = { 'O', 'N', 'F', 'I' };
235 
236 	for (i = 0; i < 4; i++) {
237 		opp = &sc->sc_parameter_page[i];
238 
239 		opp->param_signature = htole32(*(uint32_t *)sig);
240 		opp->param_pagesize = htole32(sc->sc_page_size);
241 		opp->param_blocksize = htole32(sc->sc_block_size);
242 		opp->param_sparesize = htole16(sc->sc_spare_size);
243 		opp->param_lunsize = htole32(sc->sc_lun_size);
244 		opp->param_numluns = 1;
245 
246 		opp->param_manufacturer_id = 0x00;
247 		memcpy(opp->param_manufacturer,
248 		    "NETBSD", strlen("NETBSD"));
249 		memcpy(opp->param_model,
250 		    "NANDEMULATOR", strlen("NANDEMULATOR"));
251 
252 		uint16_t features = ONFI_FEATURE_16BIT;
253 		opp->param_features = htole16(features);
254 
255 		/* the lower 4 bits contain the row address cycles
256 		 * the upper 4 bits contain the column address cycles
257 		 */
258 		opp->param_addr_cycles = sc->sc_row_cycles;
259 		opp->param_addr_cycles |= (sc->sc_column_cycles << 4);
260 
261 		opp->param_integrity_crc = nand_crc16((uint8_t *)opp, 254);
262 	}
263 
264 	sc->sc_ids[0] = 0x00;
265 	sc->sc_ids[1] = 0x00;
266 
267 	sc->sc_onfi[0] = 'O';
268 	sc->sc_onfi[1] = 'N';
269 	sc->sc_onfi[2] = 'F';
270 	sc->sc_onfi[3] = 'I';
271 
272 	sc->sc_row_mask = 0x00;
273 	for (i = 0; i < sc->sc_row_cycles; i++) {
274 		sc->sc_row_mask <<= 8;
275 		sc->sc_row_mask |= 0xff;
276 	}
277 
278 	nandemulator_device_reset(self);
279 
280 	sc->sc_nanddev = nand_attach_mi(&sc->sc_nand_if, sc->sc_dev);
281 }
282 
283 static int
284 nandemulator_detach(device_t self, int flags)
285 {
286 	struct nandemulator_softc *sc = device_private(self);
287 	int ret = 0;
288 
289 	aprint_normal_dev(sc->sc_dev, "detaching emulator\n");
290 
291 	pmf_device_deregister(sc->sc_dev);
292 
293 	if (sc->sc_nanddev != NULL)
294 		ret = config_detach(sc->sc_nanddev, flags);
295 
296 	kmem_free(sc->sc_backend, sc->sc_backend_size);
297 	kmem_free(sc->sc_parameter_page,
298 	    sizeof(struct onfi_parameter_page) * 4);
299 
300 	return ret;
301 }
302 
303 /**
304  * bring the emulated device to a known state
305  */
306 static void
307 nandemulator_device_reset(device_t self)
308 {
309 	struct nandemulator_softc *sc = device_private(self);
310 
311 	DPRINTF(("device reset\n"));
312 
313 	sc->sc_command = 0;
314 	sc->sc_register_writable = false;
315 	sc->sc_io_len = 0;
316 	sc->sc_io_pointer = NULL;
317 	sc->sc_address = 0;
318 	sc->sc_address_counter = 0;
319 
320 	sc->sc_status_register = ONFI_STATUS_RDY | ONFI_STATUS_WP;
321 }
322 
323 static void
324 nandemulator_address_chip(device_t self)
325 {
326 	struct nandemulator_softc *sc = device_private(self);
327 	size_t page, offset;
328 
329 	KASSERT(sc->sc_address_counter ==
330 	    sc->sc_column_cycles + sc->sc_row_cycles);
331 
332 	if (sc->sc_address_counter !=
333 	    sc->sc_column_cycles + sc->sc_row_cycles) {
334 		aprint_error_dev(self, "incorrect number of address cycles\n");
335 		aprint_error_dev(self, "cc: %d, rc: %d, ac: %d\n",
336 		    sc->sc_column_cycles, sc->sc_row_cycles,
337 		    sc->sc_address_counter);
338 	}
339 
340 	page = nandemulator_address_to_page(self);
341 	offset = sc->sc_page_size * page;
342 
343 	DPRINTF(("READ/PROGRAM; page: 0x%jx (row addr: 0x%jx)\n",
344 		(uintmax_t )page,
345 		(uintmax_t )offset));
346 
347 	KASSERT(offset < sc->sc_device_size);
348 
349 	if (offset >= sc->sc_device_size) {
350 		aprint_error_dev(self, "address > device size!\n");
351 		sc->sc_io_len = 0;
352 	} else {
353 		size_t addr =
354 		    nandemulator_page_to_backend_offset(self, page);
355 		size_t pageoff =
356 		    nandemulator_column_address_to_subpage(self);
357 
358 		DPRINTF(("subpage: 0x%jx\n", (uintmax_t )pageoff));
359 
360 		KASSERT(pageoff <
361 		    sc->sc_page_size + sc->sc_spare_size);
362 		KASSERT(addr < sc->sc_backend_size);
363 
364 		sc->sc_io_pointer = sc->sc_backend + addr + pageoff;
365 		sc->sc_io_len =
366 		    sc->sc_page_size + sc->sc_spare_size - pageoff;
367 	}
368 }
369 
370 static void
371 nandemulator_command(device_t self, uint8_t command)
372 {
373 	struct nandemulator_softc *sc = device_private(self);
374 	size_t offset, page;
375 
376 	sc->sc_command = command;
377 	sc->sc_register_writable = false;
378 
379 	DPRINTF(("nandemulator command: 0x%hhx\n", command));
380 
381 	switch (command) {
382 	case ONFI_READ_STATUS:
383 		sc->sc_io_pointer = &sc->sc_status_register;
384 		sc->sc_io_len = 1;
385 		break;
386 	case ONFI_RESET:
387 		nandemulator_device_reset(self);
388 		break;
389 	case ONFI_PAGE_PROGRAM:
390 		sc->sc_register_writable = true;
391 	case ONFI_READ:
392 	case ONFI_BLOCK_ERASE:
393 		sc->sc_address_counter = 0;
394 	case ONFI_READ_ID:
395 	case ONFI_READ_PARAMETER_PAGE:
396 		sc->sc_io_len = 0;
397 		sc->sc_address = 0;
398 		break;
399 	case ONFI_PAGE_PROGRAM_START:
400 		/* XXX the program should only happen here */
401 		break;
402 	case ONFI_READ_START:
403 		nandemulator_address_chip(self);
404 		break;
405 	case ONFI_BLOCK_ERASE_START:
406 		page = nandemulator_address_to_page(self);
407 		offset = sc->sc_page_size * page;
408 
409 		KASSERT(offset %
410 		    (sc->sc_block_size * sc->sc_page_size) == 0);
411 
412 		KASSERT(offset < sc->sc_device_size);
413 
414 		if (offset >= sc->sc_device_size) {
415 			aprint_error_dev(self, "address > device size!\n");
416 		} else {
417 			size_t addr =
418 			    nandemulator_page_to_backend_offset(self, page);
419 
420 			size_t blocklen =
421 			    sc->sc_block_size *
422 			    (sc->sc_page_size + sc->sc_spare_size);
423 
424 			KASSERT(addr < sc->sc_backend_size);
425 			uint8_t *block = sc->sc_backend + addr;
426 
427 			DPRINTF(("erasing block at 0x%jx\n",
428 				(uintmax_t )offset));
429 
430 			memset(block, 0xff, blocklen);
431 		}
432 		sc->sc_io_len = 0;
433 		break;
434 	default:
435 		aprint_error_dev(self,
436 		    "invalid nand command (0x%hhx)\n", command);
437 		KASSERT(false);
438 		sc->sc_io_len = 0;
439 	}
440 };
441 
442 static void
443 nandemulator_address(device_t self, uint8_t address)
444 {
445 	struct nandemulator_softc *sc = device_private(self);
446 
447 	DPRINTF(("nandemulator_address: %hhx\n", address));
448 
449 	/**
450 	 * we have to handle read id/parameter page here,
451 	 * as we can read right after giving the address.
452 	 */
453 	switch (sc->sc_command) {
454 	case ONFI_READ_ID:
455 		if (address == 0x00) {
456 			sc->sc_io_len = 2;
457 			sc->sc_io_pointer = sc->sc_ids;
458 		} else if (address == 0x20) {
459 			sc->sc_io_len = 4;
460 			sc->sc_io_pointer = sc->sc_onfi;
461 		} else {
462 			sc->sc_io_len = 0;
463 		}
464 		break;
465 	case ONFI_READ_PARAMETER_PAGE:
466 		if (address == 0x00) {
467 			sc->sc_io_len = sizeof(struct onfi_parameter_page) * 4;
468 			sc->sc_io_pointer = (uint8_t *)sc->sc_parameter_page;
469 		} else {
470 			sc->sc_io_len = 0;
471 		}
472 		break;
473 	case ONFI_PAGE_PROGRAM:
474 		sc->sc_address <<= 8;
475 		sc->sc_address |= address;
476 		sc->sc_address_counter++;
477 
478 		if (sc->sc_address_counter ==
479 		    sc->sc_column_cycles + sc->sc_row_cycles) {
480 			nandemulator_address_chip(self);
481 		}
482 		break;
483 	default:
484 		sc->sc_address <<= 8;
485 		sc->sc_address |= address;
486 		sc->sc_address_counter++;
487 	}
488 };
489 
490 static void
491 nandemulator_busy(device_t self)
492 {
493 #ifdef NANDEMULATOR_DELAYS
494 	struct nandemulator_softc *sc = device_private(self);
495 
496 	/* do some delay depending on command */
497 	switch (sc->sc_command) {
498 	case ONFI_PAGE_PROGRAM_START:
499 	case ONFI_BLOCK_ERASE_START:
500 		DELAY(10);
501 		break;
502 	case ONFI_READ_START:
503 	default:
504 		DELAY(1);
505 	}
506 #endif
507 }
508 
509 static void
510 nandemulator_read_1(device_t self, uint8_t *data)
511 {
512 	struct nandemulator_softc *sc = device_private(self);
513 
514 	KASSERT(sc->sc_io_len > 0);
515 
516 	if (sc->sc_io_len > 0) {
517 		*data = *sc->sc_io_pointer;
518 
519 		sc->sc_io_pointer++;
520 		sc->sc_io_len--;
521 	} else {
522 		aprint_error_dev(self, "reading byte from invalid location\n");
523 		*data = 0xff;
524 	}
525 }
526 
527 static void
528 nandemulator_write_1(device_t self, uint8_t data)
529 {
530 	struct nandemulator_softc *sc = device_private(self);
531 
532 	KASSERT(sc->sc_register_writable);
533 
534 	if (!sc->sc_register_writable) {
535 		aprint_error_dev(self,
536 		    "trying to write read only location without effect\n");
537 		return;
538 	}
539 
540 	KASSERT(sc->sc_io_len > 0);
541 
542 	if (sc->sc_io_len > 0) {
543 		*sc->sc_io_pointer = data;
544 
545 		sc->sc_io_pointer++;
546 		sc->sc_io_len--;
547 	} else {
548 		aprint_error_dev(self, "write to invalid location\n");
549 	}
550 }
551 
552 static void
553 nandemulator_read_2(device_t self, uint16_t *data)
554 {
555 	struct nandemulator_softc *sc = device_private(self);
556 
557 	KASSERT(sc->sc_buswidth == NANDEMULATOR_16BIT);
558 
559 	if (sc->sc_buswidth != NANDEMULATOR_16BIT) {
560 		aprint_error_dev(self,
561 		    "trying to read a word on an 8bit chip\n");
562 		return;
563 	}
564 
565 	KASSERT(sc->sc_io_len > 1);
566 
567 	if (sc->sc_io_len > 1) {
568 		*data = *(uint16_t *)sc->sc_io_pointer;
569 
570 		sc->sc_io_pointer += 2;
571 		sc->sc_io_len -= 2;
572 	} else {
573 		aprint_error_dev(self, "reading word from invalid location\n");
574 		*data = 0xffff;
575 	}
576 }
577 
578 static void
579 nandemulator_write_2(device_t self, uint16_t data)
580 {
581 	struct nandemulator_softc *sc = device_private(self);
582 
583 	KASSERT(sc->sc_register_writable);
584 
585 	if (!sc->sc_register_writable) {
586 		aprint_error_dev(self,
587 		    "trying to write read only location without effect\n");
588 		return;
589 	}
590 
591 	KASSERT(sc->sc_buswidth == NANDEMULATOR_16BIT);
592 
593 	if (sc->sc_buswidth != NANDEMULATOR_16BIT) {
594 		aprint_error_dev(self,
595 		    "trying to write a word to an 8bit chip");
596 		return;
597 	}
598 
599 	KASSERT(sc->sc_io_len > 1);
600 
601 	if (sc->sc_io_len > 1) {
602 		*(uint16_t *)sc->sc_io_pointer = data;
603 
604 		sc->sc_io_pointer += 2;
605 		sc->sc_io_len -= 2;
606 	} else {
607 		aprint_error_dev(self, "writing to invalid location");
608 	}
609 }
610 
611 static void
612 nandemulator_read_buf_1(device_t self, void *buf, size_t len)
613 {
614 	uint8_t *addr;
615 
616 	KASSERT(buf != NULL);
617 	KASSERT(len >= 1);
618 
619 	addr = buf;
620 	while (len > 0) {
621 		nandemulator_read_1(self, addr);
622 		addr++, len--;
623 	}
624 }
625 
626 static void
627 nandemulator_read_buf_2(device_t self, void *buf, size_t len)
628 {
629 	uint16_t *addr;
630 
631 	KASSERT(buf != NULL);
632 	KASSERT(len >= 2);
633 	KASSERT(!(len & 0x01));
634 
635 	addr = buf;
636 	len /= 2;
637 	while (len > 0) {
638 		nandemulator_read_2(self, addr);
639 		addr++, len--;
640 	}
641 }
642 
643 static void
644 nandemulator_write_buf_1(device_t self, const void *buf, size_t len)
645 {
646 	const uint8_t *addr;
647 
648 	KASSERT(buf != NULL);
649 	KASSERT(len >= 1);
650 
651 	addr = buf;
652 	while (len > 0) {
653 		nandemulator_write_1(self, *addr);
654 		addr++, len--;
655 	}
656 }
657 
658 static void
659 nandemulator_write_buf_2(device_t self, const void *buf, size_t len)
660 {
661 	const uint16_t *addr;
662 
663 	KASSERT(buf != NULL);
664 	KASSERT(len >= 2);
665 	KASSERT(!(len & 0x01));
666 
667 	addr = buf;
668 	len /= 2;
669 	while (len > 0) {
670 		nandemulator_write_2(self, *addr);
671 		addr++, len--;
672 	}
673 }
674 
675 static size_t
676 nandemulator_address_to_page(device_t self)
677 {
678 	struct nandemulator_softc *sc = device_private(self);
679 	uint64_t address, offset;
680 	int i;
681 
682 	address = htole64(sc->sc_address);
683 	address &= sc->sc_row_mask;
684 
685 	offset = 0;
686 	for (i = 0; i < sc->sc_row_cycles; i++) {
687 		offset <<= 8;
688 		offset |= (address & 0xff);
689 		address >>= 8;
690 	}
691 
692 	return le64toh(offset);
693 }
694 
695 static size_t
696 nandemulator_column_address_to_subpage(device_t self)
697 {
698 	struct nandemulator_softc *sc = device_private(self);
699 	uint64_t address, offset;
700 	int i;
701 
702 	address = htole64(sc->sc_address);
703 	address >>= (8 * sc->sc_row_cycles);
704 
705 	offset = 0;
706 	for (i = 0; i < sc->sc_column_cycles; i++) {
707 		offset <<= 8;
708 		offset |= (address & 0xff);
709 		address >>= 8;
710 	}
711 
712 	if (sc->sc_buswidth == NANDEMULATOR_16BIT)
713 		return (size_t )le64toh(offset << 1);
714 	else
715 		return (size_t )le64toh(offset);
716 }
717 
718 static size_t
719 nandemulator_page_to_backend_offset(device_t self, size_t page)
720 {
721 	struct nandemulator_softc *sc = device_private(self);
722 
723 	return (sc->sc_page_size + sc->sc_spare_size) * page;
724 }
725 
726 #ifdef _MODULE
727 
728 MODULE(MODULE_CLASS_DRIVER, nandemulator, "nand");
729 
730 static const struct cfiattrdata nandbuscf_iattrdata = {
731 	"nandbus", 0, { { NULL, NULL, 0 }, }
732 };
733 static const struct cfiattrdata * const nandemulator_attrs[] = {
734 	&nandbuscf_iattrdata, NULL
735 };
736 
737 CFDRIVER_DECL(nandemulator, DV_DULL, nandemulator_attrs);
738 extern struct cfattach nandemulator_ca;
739 static int nandemulatorloc[] = { -1, -1 };
740 
741 static struct cfdata nandemulator_cfdata[] = {
742 	{
743 		.cf_name = "nandemulator",
744 		.cf_atname = "nandemulator",
745 		.cf_unit = 0,
746 		.cf_fstate = FSTATE_STAR,
747 		.cf_loc = nandemulatorloc,
748 		.cf_flags = 0,
749 		.cf_pspec = NULL,
750 	},
751 	{ NULL, NULL, 0, 0, NULL, 0, NULL }
752 };
753 
754 static int
755 nandemulator_modcmd(modcmd_t cmd, void *arg)
756 {
757 	int error;
758 
759 	switch (cmd) {
760 	case MODULE_CMD_INIT:
761 		error = config_cfdriver_attach(&nandemulator_cd);
762 		if (error) {
763 			return error;
764 		}
765 
766 		error = config_cfattach_attach(nandemulator_cd.cd_name,
767 		    &nandemulator_ca);
768 		if (error) {
769 			config_cfdriver_detach(&nandemulator_cd);
770 			aprint_error("%s: unable to register cfattach\n",
771 				nandemulator_cd.cd_name);
772 
773 			return error;
774 		}
775 
776 		error = config_cfdata_attach(nandemulator_cfdata, 1);
777 		if (error) {
778 			config_cfattach_detach(nandemulator_cd.cd_name,
779 			    &nandemulator_ca);
780 			config_cfdriver_detach(&nandemulator_cd);
781 			aprint_error("%s: unable to register cfdata\n",
782 				nandemulator_cd.cd_name);
783 
784 			return error;
785 		}
786 
787 		(void)config_attach_pseudo(nandemulator_cfdata);
788 
789 		return 0;
790 
791 	case MODULE_CMD_FINI:
792 		error = config_cfdata_detach(nandemulator_cfdata);
793 		if (error) {
794 			return error;
795 		}
796 
797 		config_cfattach_detach(nandemulator_cd.cd_name,
798 		    &nandemulator_ca);
799 		config_cfdriver_detach(&nandemulator_cd);
800 
801 		return 0;
802 
803 	case MODULE_CMD_AUTOUNLOAD:
804 		/* prevent auto-unload */
805 		return EBUSY;
806 
807 	default:
808 		return ENOTTY;
809 	}
810 }
811 
812 #endif
813