xref: /netbsd-src/sys/dev/nand/nandemulator.c (revision ba65fde2d7fefa7d39838fa5fa855e62bd606b5e)
1 /*	$NetBSD: nandemulator.c,v 1.6 2012/11/03 12:45:28 ahoka 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 1.6 2012/11/03 12:45:28 ahoka 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 extern struct cfdriver nandemulator_cd;
50 void nandemulatorattach(int n);
51 
52 static int nandemulator_match(device_t, cfdata_t, void *);
53 static void nandemulator_attach(device_t, device_t, void *);
54 static int nandemulator_detach(device_t, int);
55 
56 static void nandemulator_device_reset(device_t);
57 static void nandemulator_command(device_t, uint8_t);
58 static void nandemulator_address(device_t, uint8_t);
59 static void nandemulator_busy(device_t);
60 static void nandemulator_read_1(device_t, uint8_t *);
61 static void nandemulator_write_1(device_t, uint8_t);
62 static void nandemulator_read_2(device_t, uint16_t *);
63 static void nandemulator_write_2(device_t, uint16_t);
64 static void nandemulator_read_buf_1(device_t, void *, size_t);
65 static void nandemulator_read_buf_2(device_t, void *, size_t);
66 static void nandemulator_write_buf_1(device_t, const void *, size_t);
67 static void nandemulator_write_buf_2(device_t, const void *, size_t);
68 
69 static size_t nandemulator_address_to_page(device_t);
70 static size_t nandemulator_page_to_backend_offset(device_t, size_t);
71 static size_t nandemulator_column_address_to_subpage(device_t);
72 /*
73 #define NANDEMULATOR_DEBUG 1
74 
75 #ifdef NANDEMULATOR_DEBUG
76 #warning debug enabled
77 #define DPRINTF(x)	if (nandemulatordebug) printf x
78 #define DPRINTFN(n,x)	if (nandemulatordebug>(n)) printf x
79 #else
80 #error no debug
81 #define DPRINTF(x)
82 #define DPRINTFN(n,x)
83 #endif
84 
85 #ifdef NANDEMULATOR_DEBUG
86 int	nandemulatordebug = NANDEMULATOR_DEBUG;
87 #endif
88 */
89 
90 extern int nanddebug;
91 
92 enum {
93 	NANDEMULATOR_8BIT,
94 	NANDEMULATOR_16BIT
95 };
96 
97 struct nandemulator_softc {
98 	device_t		sc_dev;
99 	device_t		sc_nanddev;
100 
101 	int			sc_buswidth;
102 
103 	struct nand_interface	sc_nand_if;
104 
105 	uint8_t			sc_command;
106 	size_t			sc_io_len;
107 	uint8_t			*sc_io_pointer;
108 	uint64_t		sc_address;
109 
110 	uint8_t			*sc_backend;
111 	size_t			sc_backend_size;
112 	size_t			sc_device_size;
113 	bool			sc_register_writable;
114 
115 	uint8_t			sc_status_register;
116 	uint8_t			sc_ids[2];
117 	uint8_t			sc_onfi[4];
118 
119 	size_t			sc_page_size;
120 	size_t			sc_block_size;
121 	size_t			sc_spare_size;
122 	size_t			sc_lun_size;
123 	uint8_t			sc_row_cycles;
124 	uint8_t			sc_column_cycles;
125 	uint64_t		sc_row_mask;
126 
127 	int			sc_address_counter;
128 
129 	struct onfi_parameter_page	*sc_parameter_page;
130 };
131 
132 CFATTACH_DECL_NEW(nandemulator, sizeof(struct nandemulator_softc),
133     nandemulator_match, nandemulator_attach, nandemulator_detach, NULL);
134 
135 void
136 nandemulatorattach(int n)
137 {
138 	int i, err;
139 	cfdata_t cf;
140 
141 	aprint_debug("nandemulator: requested %d units\n", n);
142 
143 	err = config_cfattach_attach(nandemulator_cd.cd_name,
144 	    &nandemulator_ca);
145 	if (err) {
146 		aprint_error("%s: couldn't register cfattach: %d\n",
147 		    nandemulator_cd.cd_name, err);
148 		config_cfdriver_detach(&nandemulator_cd);
149 		return;
150 	}
151 	for (i = 0; i < n; i++) {
152 		cf = kmem_alloc(sizeof(struct cfdata), KM_NOSLEEP);
153 		if (cf == NULL) {
154 			aprint_error("%s: couldn't allocate cfdata\n",
155 			    nandemulator_cd.cd_name);
156 			continue;
157 		}
158 		cf->cf_name = nandemulator_cd.cd_name;
159 		cf->cf_atname = nandemulator_cd.cd_name;
160 		cf->cf_unit = i;
161 		cf->cf_fstate = FSTATE_STAR;
162 
163 		(void)config_attach_pseudo(cf);
164 	}
165 }
166 
167 /* ARGSUSED */
168 static int
169 nandemulator_match(device_t parent, cfdata_t match, void *aux)
170 {
171 	/* pseudo device, always attaches */
172 	return 1;
173 }
174 
175 static void
176 nandemulator_attach(device_t parent, device_t self, void *aux)
177 {
178 	struct nandemulator_softc *sc = device_private(self);
179 	int i;
180 
181 	aprint_normal_dev(self, "NAND emulator\n");
182 
183 	sc->sc_dev = self;
184 
185 	nand_init_interface(&sc->sc_nand_if);
186 
187 	sc->sc_nand_if.command = &nandemulator_command;
188 	sc->sc_nand_if.address = &nandemulator_address;
189 	sc->sc_nand_if.read_buf_1 = &nandemulator_read_buf_1;
190 	sc->sc_nand_if.read_buf_2 = &nandemulator_read_buf_2;
191 	sc->sc_nand_if.read_1 = &nandemulator_read_1;
192 	sc->sc_nand_if.read_2 = &nandemulator_read_2;
193 	sc->sc_nand_if.write_buf_1 = &nandemulator_write_buf_1;
194 	sc->sc_nand_if.write_buf_2 = &nandemulator_write_buf_2;
195 	sc->sc_nand_if.write_1 = &nandemulator_write_1;
196 	sc->sc_nand_if.write_2 = &nandemulator_write_2;
197 	sc->sc_nand_if.busy = &nandemulator_busy;
198 
199 	sc->sc_nand_if.ecc.necc_code_size = 3;
200 	sc->sc_nand_if.ecc.necc_block_size = 256;
201 
202 	if (!pmf_device_register1(sc->sc_dev, NULL, NULL, NULL))
203 		aprint_error_dev(sc->sc_dev,
204 		    "couldn't establish power handler\n");
205 
206 	sc->sc_buswidth = NANDEMULATOR_16BIT;	/* 16bit for now */
207 
208 	/* hardcode these now, make it configurable later */
209 	sc->sc_device_size = 32 * 1024 * 1024; /* 32MB */
210 	sc->sc_page_size = 2048;
211 	sc->sc_block_size = 64;
212 	sc->sc_lun_size =
213 	    sc->sc_device_size / (sc->sc_page_size * sc->sc_block_size);
214 	KASSERT(sc->sc_device_size %
215 	    (sc->sc_page_size * sc->sc_block_size) == 0);
216 	sc->sc_spare_size = 64;
217 
218 	sc->sc_column_cycles = 2;
219 	sc->sc_row_cycles = 3;
220 
221 	/* init the emulator data structures */
222 	sc->sc_backend_size =
223 	    sc->sc_device_size +
224 	    sc->sc_device_size / sc->sc_page_size * sc->sc_spare_size;
225 
226 	sc->sc_backend = kmem_alloc(sc->sc_backend_size, KM_SLEEP);
227 	memset(sc->sc_backend, 0xff, sc->sc_backend_size);
228 
229 	sc->sc_parameter_page =
230 	    kmem_zalloc(sizeof(struct onfi_parameter_page) * 4, KM_SLEEP);
231 
232 	struct onfi_parameter_page *opp;
233 	uint8_t sig[4] = { 'O', 'N', 'F', 'I' };
234 
235 	for (i = 0; i < 4; i++) {
236 		opp = &sc->sc_parameter_page[i];
237 
238 		opp->param_signature = htole32(*(uint32_t *)sig);
239 		opp->param_pagesize = htole32(sc->sc_page_size);
240 		opp->param_blocksize = htole32(sc->sc_block_size);
241 		opp->param_sparesize = htole16(sc->sc_spare_size);
242 		opp->param_lunsize = htole32(sc->sc_lun_size);
243 		opp->param_numluns = 1;
244 
245 		opp->param_manufacturer_id = 0x00;
246 		memcpy(opp->param_manufacturer,
247 		    "NETBSD", strlen("NETBSD"));
248 		memcpy(opp->param_model,
249 		    "NANDEMULATOR", strlen("NANDEMULATOR"));
250 
251 		uint16_t features = ONFI_FEATURE_16BIT;
252 		opp->param_features = htole16(features);
253 
254 		/* the lower 4 bits contain the row address cycles
255 		 * the upper 4 bits contain the column address cycles
256 		 */
257 		opp->param_addr_cycles = sc->sc_row_cycles;
258 		opp->param_addr_cycles |= (sc->sc_column_cycles << 4);
259 
260 		opp->param_integrity_crc = nand_crc16((uint8_t *)opp, 254);
261 	}
262 
263 	sc->sc_ids[0] = 0x00;
264 	sc->sc_ids[1] = 0x00;
265 
266 	sc->sc_onfi[0] = 'O';
267 	sc->sc_onfi[1] = 'N';
268 	sc->sc_onfi[2] = 'F';
269 	sc->sc_onfi[3] = 'I';
270 
271 	sc->sc_row_mask = 0x00;
272 	for (i = 0; i < sc->sc_row_cycles; i++) {
273 		sc->sc_row_mask <<= 8;
274 		sc->sc_row_mask |= 0xff;
275 	}
276 
277 	nandemulator_device_reset(self);
278 
279 	sc->sc_nanddev = nand_attach_mi(&sc->sc_nand_if, sc->sc_dev);
280 }
281 
282 static int
283 nandemulator_detach(device_t self, int flags)
284 {
285 	struct nandemulator_softc *sc = device_private(self);
286 	int ret = 0;
287 
288 	aprint_normal_dev(sc->sc_dev, "detaching emulator\n");
289 
290 	pmf_device_deregister(sc->sc_dev);
291 
292 	if (sc->sc_nanddev != NULL)
293 		ret = config_detach(sc->sc_nanddev, flags);
294 
295 	kmem_free(sc->sc_backend, sc->sc_backend_size);
296 	kmem_free(sc->sc_parameter_page,
297 	    sizeof(struct onfi_parameter_page) * 4);
298 
299 	return ret;
300 }
301 
302 /**
303  * bring the emulated device to a known state
304  */
305 static void
306 nandemulator_device_reset(device_t self)
307 {
308 	struct nandemulator_softc *sc = device_private(self);
309 
310 	DPRINTF(("device reset\n"));
311 
312 	sc->sc_command = 0;
313 	sc->sc_register_writable = false;
314 	sc->sc_io_len = 0;
315 	sc->sc_io_pointer = NULL;
316 	sc->sc_address = 0;
317 	sc->sc_address_counter = 0;
318 
319 	sc->sc_status_register = ONFI_STATUS_RDY | ONFI_STATUS_WP;
320 }
321 
322 static void
323 nandemulator_address_chip(device_t self)
324 {
325 	struct nandemulator_softc *sc = device_private(self);
326 	size_t page, offset;
327 
328 	KASSERT(sc->sc_address_counter ==
329 	    sc->sc_column_cycles + sc->sc_row_cycles);
330 
331 	if (sc->sc_address_counter !=
332 	    sc->sc_column_cycles + sc->sc_row_cycles) {
333 		aprint_error_dev(self, "incorrect number of address cycles\n");
334 		aprint_error_dev(self, "cc: %d, rc: %d, ac: %d\n",
335 		    sc->sc_column_cycles, sc->sc_row_cycles,
336 		    sc->sc_address_counter);
337 	}
338 
339 	page = nandemulator_address_to_page(self);
340 	offset = sc->sc_page_size * page;
341 
342 	DPRINTF(("READ/PROGRAM; page: 0x%jx (row addr: 0x%jx)\n",
343 		(uintmax_t )page,
344 		(uintmax_t )offset));
345 
346 	KASSERT(offset < sc->sc_device_size);
347 
348 	if (offset >= sc->sc_device_size) {
349 		aprint_error_dev(self, "address > device size!\n");
350 		sc->sc_io_len = 0;
351 	} else {
352 		size_t addr =
353 		    nandemulator_page_to_backend_offset(self, page);
354 		size_t pageoff =
355 		    nandemulator_column_address_to_subpage(self);
356 
357 		DPRINTF(("subpage: 0x%jx\n", (uintmax_t )pageoff));
358 
359 		KASSERT(pageoff <
360 		    sc->sc_page_size + sc->sc_spare_size);
361 		KASSERT(addr < sc->sc_backend_size);
362 
363 		sc->sc_io_pointer = sc->sc_backend + addr + pageoff;
364 		sc->sc_io_len =
365 		    sc->sc_page_size + sc->sc_spare_size - pageoff;
366 	}
367 }
368 
369 static void
370 nandemulator_command(device_t self, uint8_t command)
371 {
372 	struct nandemulator_softc *sc = device_private(self);
373 	size_t offset, page;
374 
375 	sc->sc_command = command;
376 	sc->sc_register_writable = false;
377 
378 	DPRINTF(("nandemulator command: 0x%hhx\n", command));
379 
380 	switch (command) {
381 	case ONFI_READ_STATUS:
382 		sc->sc_io_pointer = &sc->sc_status_register;
383 		sc->sc_io_len = 1;
384 		break;
385 	case ONFI_RESET:
386 		nandemulator_device_reset(self);
387 		break;
388 	case ONFI_PAGE_PROGRAM:
389 		sc->sc_register_writable = true;
390 	case ONFI_READ:
391 	case ONFI_BLOCK_ERASE:
392 		sc->sc_address_counter = 0;
393 	case ONFI_READ_ID:
394 	case ONFI_READ_PARAMETER_PAGE:
395 		sc->sc_io_len = 0;
396 		sc->sc_address = 0;
397 		break;
398 	case ONFI_PAGE_PROGRAM_START:
399 		/* XXX the program should only happen here */
400 		break;
401 	case ONFI_READ_START:
402 		nandemulator_address_chip(self);
403 		break;
404 	case ONFI_BLOCK_ERASE_START:
405 		page = nandemulator_address_to_page(self);
406 		offset = sc->sc_page_size * page;
407 
408 		KASSERT(offset %
409 		    (sc->sc_block_size * sc->sc_page_size) == 0);
410 
411 		KASSERT(offset < sc->sc_device_size);
412 
413 		if (offset >= sc->sc_device_size) {
414 			aprint_error_dev(self, "address > device size!\n");
415 		} else {
416 			size_t addr =
417 			    nandemulator_page_to_backend_offset(self, page);
418 
419 			size_t blocklen =
420 			    sc->sc_block_size *
421 			    (sc->sc_page_size + sc->sc_spare_size);
422 
423 			KASSERT(addr < sc->sc_backend_size);
424 			uint8_t *block = sc->sc_backend + addr;
425 
426 			DPRINTF(("erasing block at 0x%jx\n",
427 				(uintmax_t )offset));
428 
429 			memset(block, 0xff, blocklen);
430 		}
431 		sc->sc_io_len = 0;
432 		break;
433 	default:
434 		aprint_error_dev(self,
435 		    "invalid nand command (0x%hhx)\n", command);
436 		KASSERT(false);
437 		sc->sc_io_len = 0;
438 	}
439 };
440 
441 static void
442 nandemulator_address(device_t self, uint8_t address)
443 {
444 	struct nandemulator_softc *sc = device_private(self);
445 
446 	DPRINTF(("nandemulator_address: %hhx\n", address));
447 
448 	/**
449 	 * we have to handle read id/parameter page here,
450 	 * as we can read right after giving the address.
451 	 */
452 	switch (sc->sc_command) {
453 	case ONFI_READ_ID:
454 		if (address == 0x00) {
455 			sc->sc_io_len = 2;
456 			sc->sc_io_pointer = sc->sc_ids;
457 		} else if (address == 0x20) {
458 			sc->sc_io_len = 4;
459 			sc->sc_io_pointer = sc->sc_onfi;
460 		} else {
461 			sc->sc_io_len = 0;
462 		}
463 		break;
464 	case ONFI_READ_PARAMETER_PAGE:
465 		if (address == 0x00) {
466 			sc->sc_io_len = sizeof(struct onfi_parameter_page) * 4;
467 			sc->sc_io_pointer = (uint8_t *)sc->sc_parameter_page;
468 		} else {
469 			sc->sc_io_len = 0;
470 		}
471 		break;
472 	case ONFI_PAGE_PROGRAM:
473 		sc->sc_address <<= 8;
474 		sc->sc_address |= address;
475 		sc->sc_address_counter++;
476 
477 		if (sc->sc_address_counter ==
478 		    sc->sc_column_cycles + sc->sc_row_cycles) {
479 			nandemulator_address_chip(self);
480 		}
481 		break;
482 	default:
483 		sc->sc_address <<= 8;
484 		sc->sc_address |= address;
485 		sc->sc_address_counter++;
486 	}
487 };
488 
489 static void
490 nandemulator_busy(device_t self)
491 {
492 #ifdef NANDEMULATOR_DELAYS
493 	struct nandemulator_softc *sc = device_private(self);
494 
495 	/* do some delay depending on command */
496 	switch (sc->sc_command) {
497 	case ONFI_PAGE_PROGRAM_START:
498 	case ONFI_BLOCK_ERASE_START:
499 		DELAY(10);
500 		break;
501 	case ONFI_READ_START:
502 	default:
503 		DELAY(1);
504 	}
505 #endif
506 }
507 
508 static void
509 nandemulator_read_1(device_t self, uint8_t *data)
510 {
511 	struct nandemulator_softc *sc = device_private(self);
512 
513 	KASSERT(sc->sc_io_len > 0);
514 
515 	if (sc->sc_io_len > 0) {
516 		*data = *sc->sc_io_pointer;
517 
518 		sc->sc_io_pointer++;
519 		sc->sc_io_len--;
520 	} else {
521 		aprint_error_dev(self, "reading byte from invalid location\n");
522 		*data = 0xff;
523 	}
524 }
525 
526 static void
527 nandemulator_write_1(device_t self, uint8_t data)
528 {
529 	struct nandemulator_softc *sc = device_private(self);
530 
531 	KASSERT(sc->sc_register_writable);
532 
533 	if (!sc->sc_register_writable) {
534 		aprint_error_dev(self,
535 		    "trying to write read only location without effect\n");
536 		return;
537 	}
538 
539 	KASSERT(sc->sc_io_len > 0);
540 
541 	if (sc->sc_io_len > 0) {
542 		*sc->sc_io_pointer = data;
543 
544 		sc->sc_io_pointer++;
545 		sc->sc_io_len--;
546 	} else {
547 		aprint_error_dev(self, "write to invalid location\n");
548 	}
549 }
550 
551 static void
552 nandemulator_read_2(device_t self, uint16_t *data)
553 {
554 	struct nandemulator_softc *sc = device_private(self);
555 
556 	KASSERT(sc->sc_buswidth == NANDEMULATOR_16BIT);
557 
558 	if (sc->sc_buswidth != NANDEMULATOR_16BIT) {
559 		aprint_error_dev(self,
560 		    "trying to read a word on an 8bit chip\n");
561 		return;
562 	}
563 
564 	KASSERT(sc->sc_io_len > 1);
565 
566 	if (sc->sc_io_len > 1) {
567 		*data = *(uint16_t *)sc->sc_io_pointer;
568 
569 		sc->sc_io_pointer += 2;
570 		sc->sc_io_len -= 2;
571 	} else {
572 		aprint_error_dev(self, "reading word from invalid location\n");
573 		*data = 0xffff;
574 	}
575 }
576 
577 static void
578 nandemulator_write_2(device_t self, uint16_t data)
579 {
580 	struct nandemulator_softc *sc = device_private(self);
581 
582 	KASSERT(sc->sc_register_writable);
583 
584 	if (!sc->sc_register_writable) {
585 		aprint_error_dev(self,
586 		    "trying to write read only location without effect\n");
587 		return;
588 	}
589 
590 	KASSERT(sc->sc_buswidth == NANDEMULATOR_16BIT);
591 
592 	if (sc->sc_buswidth != NANDEMULATOR_16BIT) {
593 		aprint_error_dev(self,
594 		    "trying to write a word to an 8bit chip");
595 		return;
596 	}
597 
598 	KASSERT(sc->sc_io_len > 1);
599 
600 	if (sc->sc_io_len > 1) {
601 		*(uint16_t *)sc->sc_io_pointer = data;
602 
603 		sc->sc_io_pointer += 2;
604 		sc->sc_io_len -= 2;
605 	} else {
606 		aprint_error_dev(self, "writing to invalid location");
607 	}
608 }
609 
610 static void
611 nandemulator_read_buf_1(device_t self, void *buf, size_t len)
612 {
613 	uint8_t *addr;
614 
615 	KASSERT(buf != NULL);
616 	KASSERT(len >= 1);
617 
618 	addr = buf;
619 	while (len > 0) {
620 		nandemulator_read_1(self, addr);
621 		addr++, len--;
622 	}
623 }
624 
625 static void
626 nandemulator_read_buf_2(device_t self, void *buf, size_t len)
627 {
628 	uint16_t *addr;
629 
630 	KASSERT(buf != NULL);
631 	KASSERT(len >= 2);
632 	KASSERT(!(len & 0x01));
633 
634 	addr = buf;
635 	len /= 2;
636 	while (len > 0) {
637 		nandemulator_read_2(self, addr);
638 		addr++, len--;
639 	}
640 }
641 
642 static void
643 nandemulator_write_buf_1(device_t self, const void *buf, size_t len)
644 {
645 	const uint8_t *addr;
646 
647 	KASSERT(buf != NULL);
648 	KASSERT(len >= 1);
649 
650 	addr = buf;
651 	while (len > 0) {
652 		nandemulator_write_1(self, *addr);
653 		addr++, len--;
654 	}
655 }
656 
657 static void
658 nandemulator_write_buf_2(device_t self, const void *buf, size_t len)
659 {
660 	const uint16_t *addr;
661 
662 	KASSERT(buf != NULL);
663 	KASSERT(len >= 2);
664 	KASSERT(!(len & 0x01));
665 
666 	addr = buf;
667 	len /= 2;
668 	while (len > 0) {
669 		nandemulator_write_2(self, *addr);
670 		addr++, len--;
671 	}
672 }
673 
674 static size_t
675 nandemulator_address_to_page(device_t self)
676 {
677 	struct nandemulator_softc *sc = device_private(self);
678 	uint64_t address, offset;
679 	int i;
680 
681 	address = htole64(sc->sc_address);
682 	address &= sc->sc_row_mask;
683 
684 	offset = 0;
685 	for (i = 0; i < sc->sc_row_cycles; i++) {
686 		offset <<= 8;
687 		offset |= (address & 0xff);
688 		address >>= 8;
689 	}
690 
691 	return le64toh(offset);
692 }
693 
694 static size_t
695 nandemulator_column_address_to_subpage(device_t self)
696 {
697 	struct nandemulator_softc *sc = device_private(self);
698 	uint64_t address, offset;
699 	int i;
700 
701 	address = htole64(sc->sc_address);
702 	address >>= (8 * sc->sc_row_cycles);
703 
704 	offset = 0;
705 	for (i = 0; i < sc->sc_column_cycles; i++) {
706 		offset <<= 8;
707 		offset |= (address & 0xff);
708 		address >>= 8;
709 	}
710 
711 	if (sc->sc_buswidth == NANDEMULATOR_16BIT)
712 		return (size_t )le64toh(offset << 1);
713 	else
714 		return (size_t )le64toh(offset);
715 }
716 
717 static size_t
718 nandemulator_page_to_backend_offset(device_t self, size_t page)
719 {
720 	struct nandemulator_softc *sc = device_private(self);
721 
722 	return (sc->sc_page_size + sc->sc_spare_size) * page;
723 }
724 
725 #ifdef _MODULE
726 
727 MODULE(MODULE_CLASS_DRIVER, nandemulator, "nand");
728 
729 static const struct cfiattrdata nandbuscf_iattrdata = {
730 	"nandbus", 0, { { NULL, NULL, 0 }, }
731 };
732 static const struct cfiattrdata * const nandemulator_attrs[] = {
733 	&nandbuscf_iattrdata, NULL
734 };
735 
736 CFDRIVER_DECL(nandemulator, DV_DULL, nandemulator_attrs);
737 extern struct cfattach nandemulator_ca;
738 static int nandemulatorloc[] = { -1, -1 };
739 
740 static struct cfdata nandemulator_cfdata[] = {
741 	{
742 		.cf_name = "nandemulator",
743 		.cf_atname = "nandemulator",
744 		.cf_unit = 0,
745 		.cf_fstate = FSTATE_STAR,
746 		.cf_loc = nandemulatorloc,
747 		.cf_flags = 0,
748 		.cf_pspec = NULL,
749 	},
750 	{ NULL, NULL, 0, 0, NULL, 0, NULL }
751 };
752 
753 static int
754 nandemulator_modcmd(modcmd_t cmd, void *arg)
755 {
756 	int error;
757 
758 	switch (cmd) {
759 	case MODULE_CMD_INIT:
760 		error = config_cfdriver_attach(&nandemulator_cd);
761 		if (error) {
762 			return error;
763 		}
764 
765 		error = config_cfattach_attach(nandemulator_cd.cd_name,
766 		    &nandemulator_ca);
767 		if (error) {
768 			config_cfdriver_detach(&nandemulator_cd);
769 			aprint_error("%s: unable to register cfattach\n",
770 				nandemulator_cd.cd_name);
771 
772 			return error;
773 		}
774 
775 		error = config_cfdata_attach(nandemulator_cfdata, 1);
776 		if (error) {
777 			config_cfattach_detach(nandemulator_cd.cd_name,
778 			    &nandemulator_ca);
779 			config_cfdriver_detach(&nandemulator_cd);
780 			aprint_error("%s: unable to register cfdata\n",
781 				nandemulator_cd.cd_name);
782 
783 			return error;
784 		}
785 
786 		(void)config_attach_pseudo(nandemulator_cfdata);
787 
788 		return 0;
789 
790 	case MODULE_CMD_FINI:
791 		error = config_cfdata_detach(nandemulator_cfdata);
792 		if (error) {
793 			return error;
794 		}
795 
796 		config_cfattach_detach(nandemulator_cd.cd_name,
797 		    &nandemulator_ca);
798 		config_cfdriver_detach(&nandemulator_cd);
799 
800 		return 0;
801 
802 	case MODULE_CMD_AUTOUNLOAD:
803 		/* prevent auto-unload */
804 		return EBUSY;
805 
806 	default:
807 		return ENOTTY;
808 	}
809 }
810 
811 #endif
812