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      1 /*	$NetBSD: nand.c,v 1.29 2021/08/07 16:19:13 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 Department of Software Engineering,
      5  *		      University of Szeged, Hungary
      6  * Copyright (c) 2010 Adam Hoka <ahoka (at) 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 /* Common driver for NAND chips implementing the ONFI 2.2 specification */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: nand.c,v 1.29 2021/08/07 16:19:13 thorpej Exp $");
     38 
     39 #include "locators.h"
     40 
     41 #include <sys/param.h>
     42 #include <sys/types.h>
     43 #include <sys/device.h>
     44 #include <sys/kmem.h>
     45 #include <sys/atomic.h>
     46 
     47 #include <dev/flash/flash.h>
     48 #include <dev/flash/flash_io.h>
     49 #include <dev/nand/nand.h>
     50 #include <dev/nand/onfi.h>
     51 #include <dev/nand/hamming.h>
     52 #include <dev/nand/nand_bbt.h>
     53 #include <dev/nand/nand_crc.h>
     54 
     55 #include "opt_nand.h"
     56 
     57 int nand_match(device_t, cfdata_t, void *);
     58 void nand_attach(device_t, device_t, void *);
     59 int nand_detach(device_t, int);
     60 bool nand_shutdown(device_t, int);
     61 
     62 int nand_print(void *, const char *);
     63 
     64 static int nand_search(device_t, cfdata_t, const int *, void *);
     65 static void nand_address_row(device_t, size_t);
     66 static inline uint8_t nand_get_status(device_t);
     67 static void nand_address_column(device_t, size_t, size_t);
     68 static int nand_fill_chip_structure(device_t, struct nand_chip *);
     69 static int nand_scan_media(device_t, struct nand_chip *);
     70 static bool nand_check_wp(device_t);
     71 
     72 CFATTACH_DECL_NEW(nand, sizeof(struct nand_softc),
     73     nand_match, nand_attach, nand_detach, NULL);
     74 
     75 #ifdef NAND_DEBUG
     76 int	nanddebug = NAND_DEBUG;
     77 #endif
     78 
     79 struct flash_interface nand_flash_if = {
     80 	.type = FLASH_TYPE_NAND,
     81 
     82 	.read = nand_flash_read,
     83 	.write = nand_flash_write,
     84 	.erase = nand_flash_erase,
     85 	.block_isbad = nand_flash_isbad,
     86 	.block_markbad = nand_flash_markbad,
     87 
     88 	.submit = nand_flash_submit
     89 };
     90 
     91 const struct nand_manufacturer nand_mfrs[] = {
     92 	{ NAND_MFR_AMD,		"AMD" },
     93 	{ NAND_MFR_FUJITSU,	"Fujitsu" },
     94 	{ NAND_MFR_RENESAS,	"Renesas" },
     95 	{ NAND_MFR_STMICRO,	"ST Micro" },
     96 	{ NAND_MFR_MICRON,	"Micron" },
     97 	{ NAND_MFR_NATIONAL,	"National" },
     98 	{ NAND_MFR_TOSHIBA,	"Toshiba" },
     99 	{ NAND_MFR_HYNIX,	"Hynix" },
    100 	{ NAND_MFR_SAMSUNG,	"Samsung" },
    101 	{ NAND_MFR_UNKNOWN,	"Unknown" }
    102 };
    103 
    104 static const char *
    105 nand_midtoname(int id)
    106 {
    107 	int i;
    108 
    109 	for (i = 0; nand_mfrs[i].id != 0; i++) {
    110 		if (nand_mfrs[i].id == id)
    111 			return nand_mfrs[i].name;
    112 	}
    113 
    114 	KASSERT(nand_mfrs[i].id == 0);
    115 
    116 	return nand_mfrs[i].name;
    117 }
    118 
    119 /* ARGSUSED */
    120 int
    121 nand_match(device_t parent, cfdata_t match, void *aux)
    122 {
    123 	/* pseudo device, always attaches */
    124 	return 1;
    125 }
    126 
    127 void
    128 nand_attach(device_t parent, device_t self, void *aux)
    129 {
    130 	struct nand_softc *sc = device_private(self);
    131 	struct nand_attach_args *naa = aux;
    132 	struct nand_chip *chip = &sc->sc_chip;
    133 
    134 	sc->sc_dev = self;
    135 	sc->controller_dev = parent;
    136 	sc->nand_if = naa->naa_nand_if;
    137 
    138 	aprint_naive("\n");
    139 
    140 	if (nand_check_wp(self)) {
    141 		aprint_error("NAND chip is write protected!\n");
    142 		return;
    143 	}
    144 
    145 	if (nand_scan_media(self, chip)) {
    146 		return;
    147 	}
    148 
    149 	nand_flash_if.erasesize = chip->nc_block_size;
    150 	nand_flash_if.page_size = chip->nc_page_size;
    151 	nand_flash_if.writesize = chip->nc_page_size;
    152 
    153 	/* allocate cache */
    154 	chip->nc_oob_cache = kmem_alloc(chip->nc_spare_size, KM_SLEEP);
    155 	chip->nc_page_cache = kmem_alloc(chip->nc_page_size, KM_SLEEP);
    156 
    157 	mutex_init(&sc->sc_device_lock, MUTEX_DEFAULT, IPL_NONE);
    158 
    159 	if (flash_sync_thread_init(&sc->sc_flash_io, self, &nand_flash_if)) {
    160 		goto error;
    161 	}
    162 
    163 	if (!pmf_device_register1(sc->sc_dev, NULL, NULL, nand_shutdown))
    164 		aprint_error_dev(sc->sc_dev,
    165 		    "couldn't establish power handler\n");
    166 
    167 #ifdef NAND_BBT
    168 	nand_bbt_init(self);
    169 	nand_bbt_scan(self);
    170 #endif
    171 
    172 	/*
    173 	 * Attach all our devices
    174 	 */
    175 	config_search(self, NULL,
    176 	    CFARGS(.search = nand_search));
    177 
    178 	return;
    179 error:
    180 	kmem_free(chip->nc_oob_cache, chip->nc_spare_size);
    181 	kmem_free(chip->nc_page_cache, chip->nc_page_size);
    182 	mutex_destroy(&sc->sc_device_lock);
    183 }
    184 
    185 static int
    186 nand_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
    187 {
    188 	struct nand_softc *sc = device_private(parent);
    189 	struct nand_chip *chip = &sc->sc_chip;
    190 	struct flash_attach_args faa;
    191 
    192 	if (cf->cf_loc[FLASHBUSCF_DYNAMIC] != 0)
    193 		return 0;
    194 
    195 	faa.flash_if = &nand_flash_if;
    196 
    197 	faa.partinfo.part_name = NULL;
    198 	faa.partinfo.part_offset = cf->cf_loc[FLASHBUSCF_OFFSET];
    199 
    200 	if (cf->cf_loc[FLASHBUSCF_SIZE] == 0) {
    201 		faa.partinfo.part_size = chip->nc_size -
    202 		    faa.partinfo.part_offset;
    203 	} else {
    204 		faa.partinfo.part_size = cf->cf_loc[FLASHBUSCF_SIZE];
    205 	}
    206 
    207 	if (cf->cf_loc[FLASHBUSCF_READONLY])
    208 		faa.partinfo.part_flags = FLASH_PART_READONLY;
    209 	else
    210 		faa.partinfo.part_flags = 0;
    211 
    212 	if (config_probe(parent, cf, &faa)) {
    213 		if (config_attach(parent, cf, &faa, nand_print,
    214 				  CFARGS_NONE) != NULL) {
    215 			return 0;
    216 		} else {
    217 			return 1;
    218 		}
    219 	}
    220 
    221 	return 1;
    222 }
    223 
    224 void
    225 nand_attach_mtdparts(device_t parent, const char *mtd_id, const char *cmdline)
    226 {
    227 	struct nand_softc *sc = device_private(parent);
    228 	struct nand_chip *chip = &sc->sc_chip;
    229 
    230 	flash_attach_mtdparts(&nand_flash_if, parent, chip->nc_size,
    231 	    mtd_id, cmdline);
    232 }
    233 
    234 int
    235 nand_detach(device_t self, int flags)
    236 {
    237 	struct nand_softc *sc = device_private(self);
    238 	struct nand_chip *chip = &sc->sc_chip;
    239 	int error = 0;
    240 
    241 	error = config_detach_children(self, flags);
    242 	if (error) {
    243 		return error;
    244 	}
    245 
    246 	flash_sync_thread_destroy(&sc->sc_flash_io);
    247 #ifdef NAND_BBT
    248 	nand_bbt_detach(self);
    249 #endif
    250 	/* free oob cache */
    251 	kmem_free(chip->nc_oob_cache, chip->nc_spare_size);
    252 	kmem_free(chip->nc_page_cache, chip->nc_page_size);
    253 	kmem_free(chip->nc_ecc_cache, chip->nc_ecc->necc_size);
    254 
    255 	mutex_destroy(&sc->sc_device_lock);
    256 
    257 	pmf_device_deregister(sc->sc_dev);
    258 
    259 	return error;
    260 }
    261 
    262 int
    263 nand_print(void *aux, const char *pnp)
    264 {
    265 	if (pnp != NULL)
    266 		aprint_normal("nand at %s\n", pnp);
    267 
    268 	return UNCONF;
    269 }
    270 
    271 /* ask for a nand driver to attach to the controller */
    272 device_t
    273 nand_attach_mi(struct nand_interface *nand_if, device_t parent)
    274 {
    275 	struct nand_attach_args arg;
    276 
    277 	KASSERT(nand_if != NULL);
    278 
    279 	/* fill the defaults if we have null pointers */
    280 	if (nand_if->program_page == NULL) {
    281 		nand_if->program_page = &nand_default_program_page;
    282 	}
    283 
    284 	if (nand_if->read_page == NULL) {
    285 		nand_if->read_page = &nand_default_read_page;
    286 	}
    287 
    288 	arg.naa_nand_if = nand_if;
    289 	return config_found(parent, &arg, nand_print,
    290 	    CFARGS(.iattr = "nandbus"));
    291 }
    292 
    293 /* default everything to reasonable values, to ease future api changes */
    294 void
    295 nand_init_interface(struct nand_interface *interface)
    296 {
    297 	interface->select = &nand_default_select;
    298 	interface->command = NULL;
    299 	interface->address = NULL;
    300 	interface->read_buf_1 = NULL;
    301 	interface->read_buf_2 = NULL;
    302 	interface->read_1 = NULL;
    303 	interface->read_2 = NULL;
    304 	interface->write_buf_1 = NULL;
    305 	interface->write_buf_2 = NULL;
    306 	interface->write_1 = NULL;
    307 	interface->write_2 = NULL;
    308 	interface->busy = NULL;
    309 
    310 	/*-
    311 	 * most drivers dont want to change this, but some implement
    312 	 * read/program in one step
    313 	 */
    314 	interface->program_page = &nand_default_program_page;
    315 	interface->read_page = &nand_default_read_page;
    316 
    317 	/* default to soft ecc, that should work everywhere */
    318 	interface->ecc_compute = &nand_default_ecc_compute;
    319 	interface->ecc_correct = &nand_default_ecc_correct;
    320 	interface->ecc_prepare = NULL;
    321 	interface->ecc.necc_code_size = 3;
    322 	interface->ecc.necc_block_size = 256;
    323 	interface->ecc.necc_type = NAND_ECC_TYPE_SW;
    324 }
    325 
    326 #if 0
    327 /* handle quirks here */
    328 static void
    329 nand_quirks(device_t self, struct nand_chip *chip)
    330 {
    331 	/* this is an example only! */
    332 	switch (chip->nc_manf_id) {
    333 	case NAND_MFR_SAMSUNG:
    334 		if (chip->nc_dev_id == 0x00) {
    335 			/* do something only samsung chips need */
    336 			/* or */
    337 			/* chip->nc_quirks |= NC_QUIRK_NO_READ_START */
    338 		}
    339 	}
    340 
    341 	return;
    342 }
    343 #endif
    344 
    345 static int
    346 nand_fill_chip_structure_legacy(device_t self, struct nand_chip *chip)
    347 {
    348 	switch (chip->nc_manf_id) {
    349 	case NAND_MFR_MICRON:
    350 		return nand_read_parameters_micron(self, chip);
    351 	case NAND_MFR_SAMSUNG:
    352 		return nand_read_parameters_samsung(self, chip);
    353 	case NAND_MFR_TOSHIBA:
    354 		return nand_read_parameters_toshiba(self, chip);
    355 	default:
    356 		return 1;
    357 	}
    358 
    359 	return 0;
    360 }
    361 
    362 /**
    363  * scan media to determine the chip's properties
    364  * this function resets the device
    365  */
    366 static int
    367 nand_scan_media(device_t self, struct nand_chip *chip)
    368 {
    369 	struct nand_softc *sc = device_private(self);
    370 	struct nand_ecc *ecc;
    371 	uint8_t onfi_signature[4];
    372 
    373 	nand_select(self, true);
    374 	nand_command(self, ONFI_RESET);
    375 	KASSERT(nand_get_status(self) & ONFI_STATUS_RDY);
    376 	nand_select(self, false);
    377 
    378 	/* check if the device implements the ONFI standard */
    379 	nand_select(self, true);
    380 	nand_command(self, ONFI_READ_ID);
    381 	nand_address(self, 0x20);
    382 	nand_read_1(self, &onfi_signature[0]);
    383 	nand_read_1(self, &onfi_signature[1]);
    384 	nand_read_1(self, &onfi_signature[2]);
    385 	nand_read_1(self, &onfi_signature[3]);
    386 	nand_select(self, false);
    387 
    388 #ifdef NAND_DEBUG
    389 	device_printf(self, "signature: %02x %02x %02x %02x\n",
    390 	    onfi_signature[0], onfi_signature[1],
    391 	    onfi_signature[2], onfi_signature[3]);
    392 #endif
    393 
    394 	if (onfi_signature[0] != 'O' || onfi_signature[1] != 'N' ||
    395 	    onfi_signature[2] != 'F' || onfi_signature[3] != 'I') {
    396 		chip->nc_isonfi = false;
    397 
    398 		aprint_normal(": Legacy NAND Flash\n");
    399 
    400 		nand_read_id(self, &chip->nc_manf_id, &chip->nc_dev_id);
    401 
    402 		if (nand_fill_chip_structure_legacy(self, chip)) {
    403 			aprint_error_dev(self,
    404 			    "can't read device parameters for legacy chip\n");
    405 			return 1;
    406 		}
    407 	} else {
    408 		chip->nc_isonfi = true;
    409 
    410 		aprint_normal(": ONFI NAND Flash\n");
    411 
    412 		nand_read_id(self, &chip->nc_manf_id, &chip->nc_dev_id);
    413 
    414 		if (nand_fill_chip_structure(self, chip)) {
    415 			aprint_error_dev(self,
    416 			    "can't read device parameters\n");
    417 			return 1;
    418 		}
    419 	}
    420 
    421 	aprint_normal_dev(self,
    422 	    "manufacturer id: 0x%.2x (%s), device id: 0x%.2x\n",
    423 	    chip->nc_manf_id,
    424 	    nand_midtoname(chip->nc_manf_id),
    425 	    chip->nc_dev_id);
    426 
    427 	aprint_normal_dev(self,
    428 	    "page size: %" PRIu32 " bytes, spare size: %" PRIu32 " bytes, "
    429 	    "block size: %" PRIu32 " bytes\n",
    430 	    chip->nc_page_size, chip->nc_spare_size, chip->nc_block_size);
    431 
    432 	aprint_normal_dev(self,
    433 	    "LUN size: %" PRIu32 " blocks, LUNs: %" PRIu8
    434 	    ", total storage size: %" PRIu64 " MB\n",
    435 	    chip->nc_lun_blocks, chip->nc_num_luns,
    436 	    chip->nc_size / 1024 / 1024);
    437 
    438 	aprint_normal_dev(self, "column cycles: %" PRIu8 ", row cycles: %"
    439 	    PRIu8 ", width: %s\n",
    440 	    chip->nc_addr_cycles_column, chip->nc_addr_cycles_row,
    441 	    (chip->nc_flags & NC_BUSWIDTH_16) ? "x16" : "x8");
    442 
    443 	ecc = chip->nc_ecc = &sc->nand_if->ecc;
    444 
    445 	/*
    446 	 * calculate the place of ecc data in oob
    447 	 * we try to be compatible with Linux here
    448 	 */
    449 	switch (chip->nc_spare_size) {
    450 	case 8:
    451 		ecc->necc_offset = 0;
    452 		break;
    453 	case 16:
    454 		ecc->necc_offset = 0;
    455 		break;
    456 	case 32:
    457 		ecc->necc_offset = 0;
    458 		break;
    459 	case 64:
    460 		ecc->necc_offset = 40;
    461 		break;
    462 	case 128:
    463 		ecc->necc_offset = 80;
    464 		break;
    465 	default:
    466 		panic("OOB size %" PRIu32 " is unexpected", chip->nc_spare_size);
    467 	}
    468 
    469 	ecc->necc_steps = chip->nc_page_size / ecc->necc_block_size;
    470 	ecc->necc_size = ecc->necc_steps * ecc->necc_code_size;
    471 
    472 	/* check if we fit in oob */
    473 	if (ecc->necc_offset + ecc->necc_size > chip->nc_spare_size) {
    474 		panic("NAND ECC bits dont fit in OOB");
    475 	}
    476 
    477 	/* TODO: mark free oob area available for file systems */
    478 
    479 	chip->nc_ecc_cache = kmem_zalloc(ecc->necc_size, KM_SLEEP);
    480 
    481 	/*
    482 	 * calculate badblock marker offset in oob
    483 	 * we try to be compatible with linux here
    484 	 */
    485 	if (chip->nc_page_size > 512)
    486 		chip->nc_badmarker_offs = 0;
    487 	else
    488 		chip->nc_badmarker_offs = 5;
    489 
    490 	/* Calculate page shift and mask */
    491 	chip->nc_page_shift = ffs(chip->nc_page_size) - 1;
    492 	chip->nc_page_mask = ~(chip->nc_page_size - 1);
    493 	/* same for block */
    494 	chip->nc_block_shift = ffs(chip->nc_block_size) - 1;
    495 	chip->nc_block_mask = ~(chip->nc_block_size - 1);
    496 
    497 	/* look for quirks here if needed in future */
    498 	/* nand_quirks(self, chip); */
    499 
    500 	return 0;
    501 }
    502 
    503 void
    504 nand_read_id(device_t self, uint8_t *manf, uint8_t *dev)
    505 {
    506 	nand_select(self, true);
    507 	nand_command(self, ONFI_READ_ID);
    508 	nand_address(self, 0x00);
    509 
    510 	nand_read_1(self, manf);
    511 	nand_read_1(self, dev);
    512 
    513 	nand_select(self, false);
    514 }
    515 
    516 int
    517 nand_read_parameter_page(device_t self, struct onfi_parameter_page *params)
    518 {
    519 	uint8_t *bufp;
    520 	uint16_t crc;
    521 	int i;//, tries = 0;
    522 
    523 	KASSERT(sizeof(*params) == 256);
    524 
    525 //read_params:
    526 //	tries++;
    527 
    528 	nand_select(self, true);
    529 	nand_command(self, ONFI_READ_PARAMETER_PAGE);
    530 	nand_address(self, 0x00);
    531 
    532 	nand_busy(self);
    533 
    534 	/* TODO check the signature if it contains at least 2 letters */
    535 
    536 	bufp = (uint8_t *)params;
    537 	/* XXX why i am not using read_buf? */
    538 	for (i = 0; i < 256; i++) {
    539 		nand_read_1(self, &bufp[i]);
    540 	}
    541 	nand_select(self, false);
    542 
    543 	/* validate the parameter page with the crc */
    544 	crc = nand_crc16(bufp, 254);
    545 
    546 	if (crc != params->param_integrity_crc) {
    547 		aprint_error_dev(self, "parameter page crc check failed\n");
    548 		/* TODO: we should read the next parameter page copy */
    549 		return 1;
    550 	}
    551 
    552 	return 0;
    553 }
    554 
    555 static int
    556 nand_fill_chip_structure(device_t self, struct nand_chip *chip)
    557 {
    558 	struct onfi_parameter_page params;
    559 	uint8_t	vendor[13], model[21];
    560 	int i;
    561 
    562 	if (nand_read_parameter_page(self, &params)) {
    563 		return 1;
    564 	}
    565 
    566 	/* strip manufacturer and model string */
    567 	strlcpy(vendor, params.param_manufacturer, sizeof(vendor));
    568 	for (i = 11; i > 0 && vendor[i] == ' '; i--)
    569 		vendor[i] = 0;
    570 	strlcpy(model, params.param_model, sizeof(model));
    571 	for (i = 19; i > 0 && model[i] == ' '; i--)
    572 		model[i] = 0;
    573 
    574 	aprint_normal_dev(self, "vendor: %s, model: %s\n", vendor, model);
    575 
    576 	chip->nc_page_size = le32toh(params.param_pagesize);
    577 	chip->nc_block_size =
    578 	    le32toh(params.param_blocksize) * chip->nc_page_size;
    579 	chip->nc_spare_size = le16toh(params.param_sparesize);
    580 	chip->nc_lun_blocks = le32toh(params.param_lunsize);
    581 	chip->nc_num_luns = params.param_numluns;
    582 
    583 	chip->nc_size =
    584 	    chip->nc_block_size * chip->nc_lun_blocks * chip->nc_num_luns;
    585 
    586 	/* the lower 4 bits contain the row address cycles */
    587 	chip->nc_addr_cycles_row = params.param_addr_cycles & 0x07;
    588 	/* the upper 4 bits contain the column address cycles */
    589 	chip->nc_addr_cycles_column = (params.param_addr_cycles & ~0x07) >> 4;
    590 
    591 	uint16_t features = le16toh(params.param_features);
    592 	if (features & ONFI_FEATURE_16BIT) {
    593 		chip->nc_flags |= NC_BUSWIDTH_16;
    594 	}
    595 
    596 	if (features & ONFI_FEATURE_EXTENDED_PARAM) {
    597 		chip->nc_flags |= NC_EXTENDED_PARAM;
    598 	}
    599 
    600 	return 0;
    601 }
    602 
    603 /* ARGSUSED */
    604 bool
    605 nand_shutdown(device_t self, int howto)
    606 {
    607 	return true;
    608 }
    609 
    610 static void
    611 nand_address_column(device_t self, size_t row, size_t column)
    612 {
    613 	struct nand_softc *sc = device_private(self);
    614 	struct nand_chip *chip = &sc->sc_chip;
    615 	uint8_t i;
    616 
    617 	DPRINTF(("addressing row: 0x%jx column: %" PRIu32 "\n",
    618 		(uintmax_t )row, column));
    619 
    620 	/* XXX TODO */
    621 	row >>= chip->nc_page_shift;
    622 
    623 	/* Write the column (subpage) address */
    624 	if (chip->nc_flags & NC_BUSWIDTH_16)
    625 		column >>= 1;
    626 	for (i = 0; i < chip->nc_addr_cycles_column; i++, column >>= 8)
    627 		nand_address(self, column & 0xff);
    628 
    629 	/* Write the row (page) address */
    630 	for (i = 0; i < chip->nc_addr_cycles_row; i++, row >>= 8)
    631 		nand_address(self, row & 0xff);
    632 }
    633 
    634 static void
    635 nand_address_row(device_t self, size_t row)
    636 {
    637 	struct nand_softc *sc = device_private(self);
    638 	struct nand_chip *chip = &sc->sc_chip;
    639 	int i;
    640 
    641 	/* XXX TODO */
    642 	row >>= chip->nc_page_shift;
    643 
    644 	/* Write the row (page) address */
    645 	for (i = 0; i < chip->nc_addr_cycles_row; i++, row >>= 8)
    646 		nand_address(self, row & 0xff);
    647 }
    648 
    649 static inline uint8_t
    650 nand_get_status(device_t self)
    651 {
    652 	uint8_t status;
    653 
    654 	nand_command(self, ONFI_READ_STATUS);
    655 	nand_busy(self);
    656 	nand_read_1(self, &status);
    657 
    658 	return status;
    659 }
    660 
    661 static bool
    662 nand_check_wp(device_t self)
    663 {
    664 	if (nand_get_status(self) & ONFI_STATUS_WP)
    665 		return false;
    666 	else
    667 		return true;
    668 }
    669 
    670 static void
    671 nand_prepare_read(device_t self, flash_off_t row, flash_off_t column)
    672 {
    673 	nand_command(self, ONFI_READ);
    674 	nand_address_column(self, row, column);
    675 	nand_command(self, ONFI_READ_START);
    676 
    677 	nand_busy(self);
    678 }
    679 
    680 /* read a page with ecc correction, default implementation */
    681 int
    682 nand_default_read_page(device_t self, size_t offset, uint8_t *data)
    683 {
    684 	struct nand_softc *sc = device_private(self);
    685 	struct nand_chip *chip = &sc->sc_chip;
    686 	size_t b, bs, e, cs;
    687 	uint8_t *ecc;
    688 	int result;
    689 
    690 	nand_prepare_read(self, offset, 0);
    691 
    692 	bs = chip->nc_ecc->necc_block_size;
    693 	cs = chip->nc_ecc->necc_code_size;
    694 
    695 	/* decide if we access by 8 or 16 bits */
    696 	if (chip->nc_flags & NC_BUSWIDTH_16) {
    697 		for (b = 0, e = 0; b < chip->nc_page_size; b += bs, e += cs) {
    698 			nand_ecc_prepare(self, NAND_ECC_READ);
    699 			nand_read_buf_2(self, data + b, bs);
    700 			nand_ecc_compute(self, data + b,
    701 			    chip->nc_ecc_cache + e);
    702 		}
    703 	} else {
    704 		for (b = 0, e = 0; b < chip->nc_page_size; b += bs, e += cs) {
    705 			nand_ecc_prepare(self, NAND_ECC_READ);
    706 			nand_read_buf_1(self, data + b, bs);
    707 			nand_ecc_compute(self, data + b,
    708 			    chip->nc_ecc_cache + e);
    709 		}
    710 	}
    711 
    712 	/* for debugging new drivers */
    713 #if 0
    714 	nand_dump_data("page", data, chip->nc_page_size);
    715 #endif
    716 
    717 	nand_read_oob(self, offset, chip->nc_oob_cache);
    718 	ecc = chip->nc_oob_cache + chip->nc_ecc->necc_offset;
    719 
    720 	/* useful for debugging new ecc drivers */
    721 #if 0
    722 	printf("dumping ecc %d\n--------------\n", chip->nc_ecc->necc_steps);
    723 	for (e = 0; e < chip->nc_ecc->necc_steps; e++) {
    724 		printf("0x");
    725 		for (b = 0; b < cs; b++) {
    726 			printf("%.2hhx", ecc[e+b]);
    727 		}
    728 		printf(" 0x");
    729 		for (b = 0; b < cs; b++) {
    730 			printf("%.2hhx", chip->nc_ecc_cache[e+b]);
    731 		}
    732 		printf("\n");
    733 	}
    734 	printf("--------------\n");
    735 #endif
    736 
    737 	for (b = 0, e = 0; b < chip->nc_page_size; b += bs, e += cs) {
    738 		result = nand_ecc_correct(self, data + b, ecc + e,
    739 		    chip->nc_ecc_cache + e);
    740 
    741 		switch (result) {
    742 		case NAND_ECC_OK:
    743 			break;
    744 		case NAND_ECC_CORRECTED:
    745 			aprint_error_dev(self,
    746 			    "data corrected with ECC at page offset 0x%jx "
    747 			    "block %zu\n", (uintmax_t)offset, b);
    748 			break;
    749 		case NAND_ECC_TWOBIT:
    750 			aprint_error_dev(self,
    751 			    "uncorrectable ECC error at page offset 0x%jx "
    752 			    "block %zu\n", (uintmax_t)offset, b);
    753 			return EIO;
    754 			break;
    755 		case NAND_ECC_INVALID:
    756 			aprint_error_dev(self,
    757 			    "invalid ECC in oob at page offset 0x%jx "
    758 			    "block %zu\n", (uintmax_t)offset, b);
    759 			return EIO;
    760 			break;
    761 		default:
    762 			panic("invalid ECC correction errno");
    763 		}
    764 	}
    765 
    766 	return 0;
    767 }
    768 
    769 int
    770 nand_default_program_page(device_t self, size_t page, const uint8_t *data)
    771 {
    772 	struct nand_softc *sc = device_private(self);
    773 	struct nand_chip *chip = &sc->sc_chip;
    774 	size_t bs, cs, e, b;
    775 	uint8_t status;
    776 	uint8_t *ecc;
    777 
    778 	nand_command(self, ONFI_PAGE_PROGRAM);
    779 	nand_address_column(self, page, 0);
    780 
    781 	nand_busy(self);
    782 
    783 	bs = chip->nc_ecc->necc_block_size;
    784 	cs = chip->nc_ecc->necc_code_size;
    785 	ecc = chip->nc_oob_cache + chip->nc_ecc->necc_offset;
    786 
    787 	/* XXX code duplication */
    788 	/* decide if we access by 8 or 16 bits */
    789 	if (chip->nc_flags & NC_BUSWIDTH_16) {
    790 		for (b = 0, e = 0; b < chip->nc_page_size; b += bs, e += cs) {
    791 			nand_ecc_prepare(self, NAND_ECC_WRITE);
    792 			nand_write_buf_2(self, data + b, bs);
    793 			nand_ecc_compute(self, data + b, ecc + e);
    794 		}
    795 		/* write oob with ecc correction code */
    796 		nand_write_buf_2(self, chip->nc_oob_cache,
    797 		    chip->nc_spare_size);
    798 	} else {
    799 		for (b = 0, e = 0; b < chip->nc_page_size; b += bs, e += cs) {
    800 			nand_ecc_prepare(self, NAND_ECC_WRITE);
    801 			nand_write_buf_1(self, data + b, bs);
    802 			nand_ecc_compute(self, data + b, ecc + e);
    803 		}
    804 		/* write oob with ecc correction code */
    805 		nand_write_buf_1(self, chip->nc_oob_cache,
    806 		    chip->nc_spare_size);
    807 	}
    808 
    809 	nand_command(self, ONFI_PAGE_PROGRAM_START);
    810 
    811 	nand_busy(self);
    812 
    813 	/* for debugging ecc */
    814 #if 0
    815 	printf("dumping ecc %d\n--------------\n", chip->nc_ecc->necc_steps);
    816 	for (e = 0; e < chip->nc_ecc->necc_steps; e++) {
    817 		printf("0x");
    818 		for (b = 0; b < cs; b++) {
    819 			printf("%.2hhx", ecc[e+b]);
    820 		}
    821 		printf("\n");
    822 	}
    823 	printf("--------------\n");
    824 #endif
    825 
    826 	status = nand_get_status(self);
    827 	KASSERT(status & ONFI_STATUS_RDY);
    828 	if (status & ONFI_STATUS_FAIL) {
    829 		aprint_error_dev(self, "page program failed!\n");
    830 		return EIO;
    831 	}
    832 
    833 	return 0;
    834 }
    835 
    836 /* read the OOB of a page */
    837 int
    838 nand_read_oob(device_t self, size_t page, uint8_t *oob)
    839 {
    840 	struct nand_softc *sc = device_private(self);
    841 	struct nand_chip *chip = &sc->sc_chip;
    842 
    843 	nand_prepare_read(self, page, chip->nc_page_size);
    844 
    845 	if (chip->nc_flags & NC_BUSWIDTH_16)
    846 		nand_read_buf_2(self, oob, chip->nc_spare_size);
    847 	else
    848 		nand_read_buf_1(self, oob, chip->nc_spare_size);
    849 
    850 	/* for debugging drivers */
    851 #if 0
    852 	nand_dump_data("oob", oob, chip->nc_spare_size);
    853 #endif
    854 
    855 	return 0;
    856 }
    857 
    858 static int
    859 nand_write_oob(device_t self, size_t offset, const void *oob)
    860 {
    861 	struct nand_softc *sc = device_private(self);
    862 	struct nand_chip *chip = &sc->sc_chip;
    863 	uint8_t status;
    864 
    865 	nand_command(self, ONFI_PAGE_PROGRAM);
    866 	nand_address_column(self, offset, chip->nc_page_size);
    867 	nand_command(self, ONFI_PAGE_PROGRAM_START);
    868 
    869 	nand_busy(self);
    870 
    871 	if (chip->nc_flags & NC_BUSWIDTH_16)
    872 		nand_write_buf_2(self, oob, chip->nc_spare_size);
    873 	else
    874 		nand_write_buf_1(self, oob, chip->nc_spare_size);
    875 
    876 	status = nand_get_status(self);
    877 	KASSERT(status & ONFI_STATUS_RDY);
    878 	if (status & ONFI_STATUS_FAIL)
    879 		return EIO;
    880 	else
    881 		return 0;
    882 }
    883 
    884 void
    885 nand_markbad(device_t self, size_t offset)
    886 {
    887 	struct nand_softc *sc = device_private(self);
    888 	struct nand_chip *chip = &sc->sc_chip;
    889 	flash_off_t blockoffset;
    890 #ifdef NAND_BBT
    891 	flash_off_t block;
    892 
    893 	block = offset / chip->nc_block_size;
    894 
    895 	nand_bbt_block_markbad(self, block);
    896 #endif
    897 	blockoffset = offset & chip->nc_block_mask;
    898 
    899 	/* check if it is already marked bad */
    900 	if (nand_isbad(self, blockoffset))
    901 		return;
    902 
    903 	nand_read_oob(self, blockoffset, chip->nc_oob_cache);
    904 
    905 	chip->nc_oob_cache[chip->nc_badmarker_offs] = 0x00;
    906 	chip->nc_oob_cache[chip->nc_badmarker_offs + 1] = 0x00;
    907 
    908 	nand_write_oob(self, blockoffset, chip->nc_oob_cache);
    909 }
    910 
    911 bool
    912 nand_isfactorybad(device_t self, flash_off_t offset)
    913 {
    914 	struct nand_softc *sc = device_private(self);
    915 	struct nand_chip *chip = &sc->sc_chip;
    916 	flash_off_t block, first_page, last_page, page;
    917 	int i;
    918 
    919 	/* Check for factory bad blocks first
    920 	 * Factory bad blocks are marked in the first or last
    921 	 * page of the blocks, see: ONFI 2.2, 3.2.2.
    922 	 */
    923 	block = offset / chip->nc_block_size;
    924 	first_page = block * chip->nc_block_size;
    925 	last_page = (block + 1) * chip->nc_block_size
    926 	    - chip->nc_page_size;
    927 
    928 	for (i = 0, page = first_page; i < 2; i++, page = last_page) {
    929 		/* address OOB */
    930 		nand_prepare_read(self, page, chip->nc_page_size);
    931 
    932 		if (chip->nc_flags & NC_BUSWIDTH_16) {
    933 			uint16_t word;
    934 			nand_read_2(self, &word);
    935 			if (word == 0x0000)
    936 				return true;
    937 		} else {
    938 			uint8_t byte;
    939 			nand_read_1(self, &byte);
    940 			if (byte == 0x00)
    941 				return true;
    942 		}
    943 	}
    944 
    945 	return false;
    946 }
    947 
    948 bool
    949 nand_iswornoutbad(device_t self, flash_off_t offset)
    950 {
    951 	struct nand_softc *sc = device_private(self);
    952 	struct nand_chip *chip = &sc->sc_chip;
    953 	flash_off_t block;
    954 
    955 	/* we inspect the first page of the block */
    956 	block = offset & chip->nc_block_mask;
    957 
    958 	/* Linux/u-boot compatible badblock handling */
    959 	if (chip->nc_flags & NC_BUSWIDTH_16) {
    960 		uint16_t word, mark;
    961 
    962 		nand_prepare_read(self, block,
    963 		    chip->nc_page_size + (chip->nc_badmarker_offs & 0xfe));
    964 
    965 		nand_read_2(self, &word);
    966 		mark = htole16(word);
    967 		if (chip->nc_badmarker_offs & 0x01)
    968 			mark >>= 8;
    969 		if ((mark & 0xff) != 0xff)
    970 			return true;
    971 	} else {
    972 		uint8_t byte;
    973 
    974 		nand_prepare_read(self, block,
    975 		    chip->nc_page_size + chip->nc_badmarker_offs);
    976 
    977 		nand_read_1(self, &byte);
    978 		if (byte != 0xff)
    979 			return true;
    980 	}
    981 
    982 	return false;
    983 }
    984 
    985 bool
    986 nand_isbad(device_t self, flash_off_t offset)
    987 {
    988 #ifdef NAND_BBT
    989 	struct nand_softc *sc = device_private(self);
    990 	struct nand_chip *chip = &sc->sc_chip;
    991 	flash_off_t block;
    992 
    993 	block = offset / chip->nc_block_size;
    994 
    995 	return nand_bbt_block_isbad(self, block);
    996 #else
    997 	/* ONFI host requirement */
    998 	if (nand_isfactorybad(self, offset))
    999 		return true;
   1000 
   1001 	/* Look for Linux/U-Boot compatible bad marker */
   1002 	if (nand_iswornoutbad(self, offset))
   1003 		return true;
   1004 
   1005 	return false;
   1006 #endif
   1007 }
   1008 
   1009 int
   1010 nand_erase_block(device_t self, size_t offset)
   1011 {
   1012 	uint8_t status;
   1013 
   1014 	/* xxx calculate first page of block for address? */
   1015 
   1016 	nand_command(self, ONFI_BLOCK_ERASE);
   1017 	nand_address_row(self, offset);
   1018 	nand_command(self, ONFI_BLOCK_ERASE_START);
   1019 
   1020 	nand_busy(self);
   1021 
   1022 	status = nand_get_status(self);
   1023 	KASSERT(status & ONFI_STATUS_RDY);
   1024 	if (status & ONFI_STATUS_FAIL) {
   1025 		aprint_error_dev(self, "block erase failed!\n");
   1026 		nand_markbad(self, offset);
   1027 		return EIO;
   1028 	} else {
   1029 		return 0;
   1030 	}
   1031 }
   1032 
   1033 /* default functions for driver development */
   1034 
   1035 /* default ECC using hamming code of 256 byte chunks */
   1036 int
   1037 nand_default_ecc_compute(device_t self, const uint8_t *data, uint8_t *code)
   1038 {
   1039 	hamming_compute_256(data, code);
   1040 
   1041 	return 0;
   1042 }
   1043 
   1044 int
   1045 nand_default_ecc_correct(device_t self, uint8_t *data, const uint8_t *origcode,
   1046 	const uint8_t *compcode)
   1047 {
   1048 	return hamming_correct_256(data, origcode, compcode);
   1049 }
   1050 
   1051 void
   1052 nand_default_select(device_t self, bool enable)
   1053 {
   1054 	/* do nothing */
   1055 	return;
   1056 }
   1057 
   1058 /* implementation of the block device API */
   1059 
   1060 int
   1061 nand_flash_submit(device_t self, struct buf * const bp)
   1062 {
   1063 	struct nand_softc *sc = device_private(self);
   1064 
   1065 	return flash_io_submit(&sc->sc_flash_io, bp);
   1066 }
   1067 
   1068 /*
   1069  * handle (page) unaligned write to nand
   1070  */
   1071 static int
   1072 nand_flash_write_unaligned(device_t self, flash_off_t offset, size_t len,
   1073     size_t *retlen, const uint8_t *buf)
   1074 {
   1075 	struct nand_softc *sc = device_private(self);
   1076 	struct nand_chip *chip = &sc->sc_chip;
   1077 	flash_off_t first, last, firstoff;
   1078 	const uint8_t *bufp;
   1079 	flash_off_t addr;
   1080 	size_t left, count;
   1081 	int error = 0, i;
   1082 
   1083 	first = offset & chip->nc_page_mask;
   1084 	firstoff = offset & ~chip->nc_page_mask;
   1085 	/* XXX check if this should be len - 1 */
   1086 	last = (offset + len) & chip->nc_page_mask;
   1087 	count = last - first + 1;
   1088 
   1089 	addr = first;
   1090 	*retlen = 0;
   1091 
   1092 	mutex_enter(&sc->sc_device_lock);
   1093 	if (count == 1) {
   1094 		if (nand_isbad(self, addr)) {
   1095 			aprint_error_dev(self,
   1096 			    "nand_flash_write_unaligned: "
   1097 			    "bad block encountered\n");
   1098 			error = EIO;
   1099 			goto out;
   1100 		}
   1101 
   1102 		error = nand_read_page(self, addr, chip->nc_page_cache);
   1103 		if (error) {
   1104 			goto out;
   1105 		}
   1106 
   1107 		memcpy(chip->nc_page_cache + firstoff, buf, len);
   1108 
   1109 		error = nand_program_page(self, addr, chip->nc_page_cache);
   1110 		if (error) {
   1111 			goto out;
   1112 		}
   1113 
   1114 		*retlen = len;
   1115 		goto out;
   1116 	}
   1117 
   1118 	bufp = buf;
   1119 	left = len;
   1120 
   1121 	for (i = 0; i < count && left != 0; i++) {
   1122 		if (nand_isbad(self, addr)) {
   1123 			aprint_error_dev(self,
   1124 			    "nand_flash_write_unaligned: "
   1125 			    "bad block encountered\n");
   1126 			error = EIO;
   1127 			goto out;
   1128 		}
   1129 
   1130 		if (i == 0) {
   1131 			error = nand_read_page(self,
   1132 			    addr, chip->nc_page_cache);
   1133 			if (error) {
   1134 				goto out;
   1135 			}
   1136 
   1137 			memcpy(chip->nc_page_cache + firstoff,
   1138 			    bufp, chip->nc_page_size - firstoff);
   1139 
   1140 			printf("program page: %s: %d\n", __FILE__, __LINE__);
   1141 			error = nand_program_page(self,
   1142 			    addr, chip->nc_page_cache);
   1143 			if (error) {
   1144 				goto out;
   1145 			}
   1146 
   1147 			bufp += chip->nc_page_size - firstoff;
   1148 			left -= chip->nc_page_size - firstoff;
   1149 			*retlen += chip->nc_page_size - firstoff;
   1150 
   1151 		} else if (i == count - 1) {
   1152 			error = nand_read_page(self,
   1153 			    addr, chip->nc_page_cache);
   1154 			if (error) {
   1155 				goto out;
   1156 			}
   1157 
   1158 			memcpy(chip->nc_page_cache, bufp, left);
   1159 
   1160 			error = nand_program_page(self,
   1161 			    addr, chip->nc_page_cache);
   1162 			if (error) {
   1163 				goto out;
   1164 			}
   1165 
   1166 			*retlen += left;
   1167 			KASSERT(left < chip->nc_page_size);
   1168 
   1169 		} else {
   1170 			/* XXX debug */
   1171 			if (left > chip->nc_page_size) {
   1172 				printf("left: %zu, i: %d, count: %zu\n",
   1173 				    left, i, count);
   1174 			}
   1175 			KASSERT(left > chip->nc_page_size);
   1176 
   1177 			error = nand_program_page(self, addr, bufp);
   1178 			if (error) {
   1179 				goto out;
   1180 			}
   1181 
   1182 			bufp += chip->nc_page_size;
   1183 			left -= chip->nc_page_size;
   1184 			*retlen += chip->nc_page_size;
   1185 		}
   1186 
   1187 		addr += chip->nc_page_size;
   1188 	}
   1189 
   1190 	KASSERT(*retlen == len);
   1191 out:
   1192 	mutex_exit(&sc->sc_device_lock);
   1193 
   1194 	return error;
   1195 }
   1196 
   1197 int
   1198 nand_flash_write(device_t self, flash_off_t offset, size_t len, size_t *retlen,
   1199     const uint8_t *buf)
   1200 {
   1201 	struct nand_softc *sc = device_private(self);
   1202 	struct nand_chip *chip = &sc->sc_chip;
   1203 	const uint8_t *bufp;
   1204 	size_t pages, page;
   1205 	daddr_t addr;
   1206 	int error = 0;
   1207 
   1208 	if ((offset + len) > chip->nc_size) {
   1209 		DPRINTF(("nand_flash_write: write (off: 0x%jx, len: %ju),"
   1210 			" is over device size (0x%jx)\n",
   1211 			(uintmax_t)offset, (uintmax_t)len,
   1212 			(uintmax_t)chip->nc_size));
   1213 		return EINVAL;
   1214 	}
   1215 
   1216 	if (len % chip->nc_page_size != 0 ||
   1217 	    offset % chip->nc_page_size != 0) {
   1218 		return nand_flash_write_unaligned(self,
   1219 		    offset, len, retlen, buf);
   1220 	}
   1221 
   1222 	pages = len / chip->nc_page_size;
   1223 	KASSERT(pages != 0);
   1224 	*retlen = 0;
   1225 
   1226 	addr = offset;
   1227 	bufp = buf;
   1228 
   1229 	mutex_enter(&sc->sc_device_lock);
   1230 	for (page = 0; page < pages; page++) {
   1231 		/* do we need this check here? */
   1232 		if (nand_isbad(self, addr)) {
   1233 			aprint_error_dev(self,
   1234 			    "nand_flash_write: bad block encountered\n");
   1235 
   1236 			error = EIO;
   1237 			goto out;
   1238 		}
   1239 
   1240 		error = nand_program_page(self, addr, bufp);
   1241 		if (error) {
   1242 			goto out;
   1243 		}
   1244 
   1245 		addr += chip->nc_page_size;
   1246 		bufp += chip->nc_page_size;
   1247 		*retlen += chip->nc_page_size;
   1248 	}
   1249 out:
   1250 	mutex_exit(&sc->sc_device_lock);
   1251 	DPRINTF(("page programming: retlen: %" PRIu32 ", len: %" PRIu32 "\n", *retlen, len));
   1252 
   1253 	return error;
   1254 }
   1255 
   1256 /*
   1257  * handle (page) unaligned read from nand
   1258  */
   1259 static int
   1260 nand_flash_read_unaligned(device_t self, size_t offset,
   1261     size_t len, size_t *retlen, uint8_t *buf)
   1262 {
   1263 	struct nand_softc *sc = device_private(self);
   1264 	struct nand_chip *chip = &sc->sc_chip;
   1265 	daddr_t first, last, count, firstoff;
   1266 	uint8_t *bufp;
   1267 	daddr_t addr;
   1268 	size_t left;
   1269 	int error = 0, i;
   1270 
   1271 	first = offset & chip->nc_page_mask;
   1272 	firstoff = offset & ~chip->nc_page_mask;
   1273 	last = (offset + len) & chip->nc_page_mask;
   1274 	count = (last - first) / chip->nc_page_size + 1;
   1275 
   1276 	addr = first;
   1277 	bufp = buf;
   1278 	left = len;
   1279 	*retlen = 0;
   1280 
   1281 	mutex_enter(&sc->sc_device_lock);
   1282 	if (count == 1) {
   1283 		error = nand_read_page(self, addr, chip->nc_page_cache);
   1284 		if (error) {
   1285 			goto out;
   1286 		}
   1287 
   1288 		memcpy(bufp, chip->nc_page_cache + firstoff, len);
   1289 
   1290 		*retlen = len;
   1291 		goto out;
   1292 	}
   1293 
   1294 	for (i = 0; i < count && left != 0; i++) {
   1295 		error = nand_read_page(self, addr, chip->nc_page_cache);
   1296 		if (error) {
   1297 			goto out;
   1298 		}
   1299 
   1300 		if (i == 0) {
   1301 			memcpy(bufp, chip->nc_page_cache + firstoff,
   1302 			    chip->nc_page_size - firstoff);
   1303 
   1304 			bufp += chip->nc_page_size - firstoff;
   1305 			left -= chip->nc_page_size - firstoff;
   1306 			*retlen += chip->nc_page_size - firstoff;
   1307 
   1308 		} else if (i == count - 1) {
   1309 			memcpy(bufp, chip->nc_page_cache, left);
   1310 			*retlen += left;
   1311 			KASSERT(left < chip->nc_page_size);
   1312 
   1313 		} else {
   1314 			memcpy(bufp, chip->nc_page_cache, chip->nc_page_size);
   1315 
   1316 			bufp += chip->nc_page_size;
   1317 			left -= chip->nc_page_size;
   1318 			*retlen += chip->nc_page_size;
   1319 		}
   1320 
   1321 		addr += chip->nc_page_size;
   1322 	}
   1323 	KASSERT(*retlen == len);
   1324 out:
   1325 	mutex_exit(&sc->sc_device_lock);
   1326 
   1327 	return error;
   1328 }
   1329 
   1330 int
   1331 nand_flash_read(device_t self, flash_off_t offset, size_t len, size_t *retlen,
   1332     uint8_t *buf)
   1333 {
   1334 	struct nand_softc *sc = device_private(self);
   1335 	struct nand_chip *chip = &sc->sc_chip;
   1336 	uint8_t *bufp;
   1337 	size_t addr;
   1338 	size_t i, pages;
   1339 	int error = 0;
   1340 
   1341 	*retlen = 0;
   1342 
   1343 	DPRINTF(("nand_flash_read: off: 0x%jx, len: %" PRIu32 "\n",
   1344 		(uintmax_t)offset, len));
   1345 
   1346 	if (__predict_false((offset + len) > chip->nc_size)) {
   1347 		DPRINTF(("nand_flash_read: read (off: 0x%jx, len: %" PRIu32 "),"
   1348 			" is over device size (%ju)\n", (uintmax_t)offset,
   1349 			len, (uintmax_t)chip->nc_size));
   1350 		return EINVAL;
   1351 	}
   1352 
   1353 	/* Handle unaligned access, shouldnt be needed when using the
   1354 	 * block device, as strategy handles it, so only low level
   1355 	 * accesses will use this path
   1356 	 */
   1357 	/* XXX^2 */
   1358 #if 0
   1359 	if (len < chip->nc_page_size)
   1360 		panic("TODO page size is larger than read size");
   1361 #endif
   1362 
   1363 	if (len % chip->nc_page_size != 0 ||
   1364 	    offset % chip->nc_page_size != 0) {
   1365 		return nand_flash_read_unaligned(self,
   1366 		    offset, len, retlen, buf);
   1367 	}
   1368 
   1369 	bufp = buf;
   1370 	addr = offset;
   1371 	pages = len / chip->nc_page_size;
   1372 
   1373 	mutex_enter(&sc->sc_device_lock);
   1374 	for (i = 0; i < pages; i++) {
   1375 		/* XXX do we need this check here? */
   1376 		if (nand_isbad(self, addr)) {
   1377 			aprint_error_dev(self, "bad block encountered\n");
   1378 			error = EIO;
   1379 			goto out;
   1380 		}
   1381 		error = nand_read_page(self, addr, bufp);
   1382 		if (error)
   1383 			goto out;
   1384 
   1385 		bufp += chip->nc_page_size;
   1386 		addr += chip->nc_page_size;
   1387 		*retlen += chip->nc_page_size;
   1388 	}
   1389 out:
   1390 	mutex_exit(&sc->sc_device_lock);
   1391 
   1392 	return error;
   1393 }
   1394 
   1395 int
   1396 nand_flash_isbad(device_t self, flash_off_t ofs, bool *is_bad)
   1397 {
   1398 	struct nand_softc *sc = device_private(self);
   1399 	struct nand_chip *chip = &sc->sc_chip;
   1400 	bool result;
   1401 
   1402 	if (ofs > chip->nc_size) {
   1403 		DPRINTF(("nand_flash_isbad: offset 0x%jx is larger than"
   1404 			" device size (0x%jx)\n", (uintmax_t)ofs,
   1405 			(uintmax_t)chip->nc_size));
   1406 		return EINVAL;
   1407 	}
   1408 
   1409 	if (ofs % chip->nc_block_size != 0) {
   1410 		DPRINTF(("offset (0x%jx) is not a multiple of block size "
   1411 			"(%ju)",
   1412 			(uintmax_t)ofs, (uintmax_t)chip->nc_block_size));
   1413 		return EINVAL;
   1414 	}
   1415 
   1416 	mutex_enter(&sc->sc_device_lock);
   1417 	result = nand_isbad(self, ofs);
   1418 	mutex_exit(&sc->sc_device_lock);
   1419 
   1420 	*is_bad = result;
   1421 
   1422 	return 0;
   1423 }
   1424 
   1425 int
   1426 nand_flash_markbad(device_t self, flash_off_t ofs)
   1427 {
   1428 	struct nand_softc *sc = device_private(self);
   1429 	struct nand_chip *chip = &sc->sc_chip;
   1430 
   1431 	if (ofs > chip->nc_size) {
   1432 		DPRINTF(("nand_flash_markbad: offset 0x%jx is larger than"
   1433 			" device size (0x%jx)\n", ofs,
   1434 			(uintmax_t)chip->nc_size));
   1435 		return EINVAL;
   1436 	}
   1437 
   1438 	if (ofs % chip->nc_block_size != 0) {
   1439 		panic("offset (%ju) is not a multiple of block size (%ju)",
   1440 		    (uintmax_t)ofs, (uintmax_t)chip->nc_block_size);
   1441 	}
   1442 
   1443 	mutex_enter(&sc->sc_device_lock);
   1444 	nand_markbad(self, ofs);
   1445 	mutex_exit(&sc->sc_device_lock);
   1446 
   1447 	return 0;
   1448 }
   1449 
   1450 int
   1451 nand_flash_erase(device_t self,
   1452     struct flash_erase_instruction *ei)
   1453 {
   1454 	struct nand_softc *sc = device_private(self);
   1455 	struct nand_chip *chip = &sc->sc_chip;
   1456 	flash_off_t addr;
   1457 	int error = 0;
   1458 
   1459 	if (ei->ei_addr < 0 || ei->ei_len < chip->nc_block_size)
   1460 		return EINVAL;
   1461 
   1462 	if (ei->ei_addr + ei->ei_len > chip->nc_size) {
   1463 		DPRINTF(("nand_flash_erase: erase address is over the end"
   1464 			" of the device\n"));
   1465 		return EINVAL;
   1466 	}
   1467 
   1468 	if (ei->ei_addr % chip->nc_block_size != 0) {
   1469 		aprint_error_dev(self,
   1470 		    "nand_flash_erase: ei_addr (%ju) is not"
   1471 		    " a multiple of block size (%ju)",
   1472 		    (uintmax_t)ei->ei_addr,
   1473 		    (uintmax_t)chip->nc_block_size);
   1474 		return EINVAL;
   1475 	}
   1476 
   1477 	if (ei->ei_len % chip->nc_block_size != 0) {
   1478 		aprint_error_dev(self,
   1479 		    "nand_flash_erase: ei_len (%ju) is not"
   1480 		    " a multiple of block size (%ju)",
   1481 		    (uintmax_t)ei->ei_len,
   1482 		    (uintmax_t)chip->nc_block_size);
   1483 		return EINVAL;
   1484 	}
   1485 
   1486 	mutex_enter(&sc->sc_device_lock);
   1487 	addr = ei->ei_addr;
   1488 	while (addr < ei->ei_addr + ei->ei_len) {
   1489 		if (nand_isbad(self, addr)) {
   1490 			aprint_error_dev(self, "bad block encountered\n");
   1491 			ei->ei_state = FLASH_ERASE_FAILED;
   1492 			error = EIO;
   1493 			goto out;
   1494 		}
   1495 
   1496 		error = nand_erase_block(self, addr);
   1497 		if (error) {
   1498 			ei->ei_state = FLASH_ERASE_FAILED;
   1499 			goto out;
   1500 		}
   1501 
   1502 		addr += chip->nc_block_size;
   1503 	}
   1504 	mutex_exit(&sc->sc_device_lock);
   1505 
   1506 	ei->ei_state = FLASH_ERASE_DONE;
   1507 	if (ei->ei_callback != NULL) {
   1508 		ei->ei_callback(ei);
   1509 	}
   1510 
   1511 	return 0;
   1512 out:
   1513 	mutex_exit(&sc->sc_device_lock);
   1514 
   1515 	return error;
   1516 }
   1517 
   1518 MODULE(MODULE_CLASS_DRIVER, nand, "flash");
   1519 
   1520 #ifdef _MODULE
   1521 #include "ioconf.c"
   1522 #endif
   1523 
   1524 static int
   1525 nand_modcmd(modcmd_t cmd, void *opaque)
   1526 {
   1527 	switch (cmd) {
   1528 	case MODULE_CMD_INIT:
   1529 #ifdef _MODULE
   1530 		return config_init_component(cfdriver_ioconf_nand,
   1531 		    cfattach_ioconf_nand, cfdata_ioconf_nand);
   1532 #else
   1533 		return 0;
   1534 #endif
   1535 	case MODULE_CMD_FINI:
   1536 #ifdef _MODULE
   1537 		return config_fini_component(cfdriver_ioconf_nand,
   1538 		    cfattach_ioconf_nand, cfdata_ioconf_nand);
   1539 #else
   1540 		return 0;
   1541 #endif
   1542 	default:
   1543 		return ENOTTY;
   1544 	}
   1545 }
   1546