1 // SPDX-License-Identifier: GPL-2.0+
2 /* Freescale Enhanced Local Bus Controller FCM NAND driver
3  *
4  * Copyright (c) 2006-2008 Freescale Semiconductor
5  *
6  * Authors: Nick Spence <nick.spence@freescale.com>,
7  *          Scott Wood <scottwood@freescale.com>
8  */
9 
10 #include <common.h>
11 #include <malloc.h>
12 #include <nand.h>
13 
14 #include <linux/mtd/mtd.h>
15 #include <linux/mtd/rawnand.h>
16 #include <linux/mtd/nand_ecc.h>
17 
18 #include <asm/io.h>
19 #include <linux/errno.h>
20 
21 #ifdef VERBOSE_DEBUG
22 #define DEBUG_ELBC
23 #define vdbg(format, arg...) printf("DEBUG: " format, ##arg)
24 #else
25 #define vdbg(format, arg...) do {} while (0)
26 #endif
27 
28 /* Can't use plain old DEBUG because the linux mtd
29  * headers define it as a macro.
30  */
31 #ifdef DEBUG_ELBC
32 #define dbg(format, arg...) printf("DEBUG: " format, ##arg)
33 #else
34 #define dbg(format, arg...) do {} while (0)
35 #endif
36 
37 #define MAX_BANKS 8
38 #define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */
39 
40 #define LTESR_NAND_MASK (LTESR_FCT | LTESR_PAR | LTESR_CC)
41 
42 struct fsl_elbc_ctrl;
43 
44 /* mtd information per set */
45 
46 struct fsl_elbc_mtd {
47 	struct nand_chip chip;
48 	struct fsl_elbc_ctrl *ctrl;
49 
50 	struct device *dev;
51 	int bank;               /* Chip select bank number           */
52 	u8 __iomem *vbase;      /* Chip select base virtual address  */
53 	int page_size;          /* NAND page size (0=512, 1=2048)    */
54 	unsigned int fmr;       /* FCM Flash Mode Register value     */
55 };
56 
57 /* overview of the fsl elbc controller */
58 
59 struct fsl_elbc_ctrl {
60 	struct nand_hw_control controller;
61 	struct fsl_elbc_mtd *chips[MAX_BANKS];
62 
63 	/* device info */
64 	fsl_lbc_t *regs;
65 	u8 __iomem *addr;        /* Address of assigned FCM buffer        */
66 	unsigned int page;       /* Last page written to / read from      */
67 	unsigned int read_bytes; /* Number of bytes read during command   */
68 	unsigned int column;     /* Saved column from SEQIN               */
69 	unsigned int index;      /* Pointer to next byte to 'read'        */
70 	unsigned int status;     /* status read from LTESR after last op  */
71 	unsigned int mdr;        /* UPM/FCM Data Register value           */
72 	unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
73 	unsigned int oob;        /* Non zero if operating on OOB data     */
74 };
75 
76 /* These map to the positions used by the FCM hardware ECC generator */
77 
78 /* Small Page FLASH with FMR[ECCM] = 0 */
79 static struct nand_ecclayout fsl_elbc_oob_sp_eccm0 = {
80 	.eccbytes = 3,
81 	.eccpos = {6, 7, 8},
82 	.oobfree = { {0, 5}, {9, 7} },
83 };
84 
85 /* Small Page FLASH with FMR[ECCM] = 1 */
86 static struct nand_ecclayout fsl_elbc_oob_sp_eccm1 = {
87 	.eccbytes = 3,
88 	.eccpos = {8, 9, 10},
89 	.oobfree = { {0, 5}, {6, 2}, {11, 5} },
90 };
91 
92 /* Large Page FLASH with FMR[ECCM] = 0 */
93 static struct nand_ecclayout fsl_elbc_oob_lp_eccm0 = {
94 	.eccbytes = 12,
95 	.eccpos = {6, 7, 8, 22, 23, 24, 38, 39, 40, 54, 55, 56},
96 	.oobfree = { {1, 5}, {9, 13}, {25, 13}, {41, 13}, {57, 7} },
97 };
98 
99 /* Large Page FLASH with FMR[ECCM] = 1 */
100 static struct nand_ecclayout fsl_elbc_oob_lp_eccm1 = {
101 	.eccbytes = 12,
102 	.eccpos = {8, 9, 10, 24, 25, 26, 40, 41, 42, 56, 57, 58},
103 	.oobfree = { {1, 7}, {11, 13}, {27, 13}, {43, 13}, {59, 5} },
104 };
105 
106 /*
107  * fsl_elbc_oob_lp_eccm* specify that LP NAND's OOB free area starts at offset
108  * 1, so we have to adjust bad block pattern. This pattern should be used for
109  * x8 chips only. So far hardware does not support x16 chips anyway.
110  */
111 static u8 scan_ff_pattern[] = { 0xff, };
112 
113 static struct nand_bbt_descr largepage_memorybased = {
114 	.options = 0,
115 	.offs = 0,
116 	.len = 1,
117 	.pattern = scan_ff_pattern,
118 };
119 
120 /*
121  * ELBC may use HW ECC, so that OOB offsets, that NAND core uses for bbt,
122  * interfere with ECC positions, that's why we implement our own descriptors.
123  * OOB {11, 5}, works for both SP and LP chips, with ECCM = 1 and ECCM = 0.
124  */
125 static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
126 static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };
127 
128 static struct nand_bbt_descr bbt_main_descr = {
129 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
130 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
131 	.offs =	11,
132 	.len = 4,
133 	.veroffs = 15,
134 	.maxblocks = 4,
135 	.pattern = bbt_pattern,
136 };
137 
138 static struct nand_bbt_descr bbt_mirror_descr = {
139 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
140 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
141 	.offs =	11,
142 	.len = 4,
143 	.veroffs = 15,
144 	.maxblocks = 4,
145 	.pattern = mirror_pattern,
146 };
147 
148 /*=================================*/
149 
150 /*
151  * Set up the FCM hardware block and page address fields, and the fcm
152  * structure addr field to point to the correct FCM buffer in memory
153  */
154 static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
155 {
156 	struct nand_chip *chip = mtd_to_nand(mtd);
157 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
158 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
159 	fsl_lbc_t *lbc = ctrl->regs;
160 	int buf_num;
161 
162 	ctrl->page = page_addr;
163 
164 	if (priv->page_size) {
165 		out_be32(&lbc->fbar, page_addr >> 6);
166 		out_be32(&lbc->fpar,
167 			 ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
168 			 (oob ? FPAR_LP_MS : 0) | column);
169 		buf_num = (page_addr & 1) << 2;
170 	} else {
171 		out_be32(&lbc->fbar, page_addr >> 5);
172 		out_be32(&lbc->fpar,
173 			 ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
174 			 (oob ? FPAR_SP_MS : 0) | column);
175 		buf_num = page_addr & 7;
176 	}
177 
178 	ctrl->addr = priv->vbase + buf_num * 1024;
179 	ctrl->index = column;
180 
181 	/* for OOB data point to the second half of the buffer */
182 	if (oob)
183 		ctrl->index += priv->page_size ? 2048 : 512;
184 
185 	vdbg("set_addr: bank=%d, ctrl->addr=0x%p (0x%p), "
186 	     "index %x, pes %d ps %d\n",
187 	     buf_num, ctrl->addr, priv->vbase, ctrl->index,
188 	     chip->phys_erase_shift, chip->page_shift);
189 }
190 
191 /*
192  * execute FCM command and wait for it to complete
193  */
194 static int fsl_elbc_run_command(struct mtd_info *mtd)
195 {
196 	struct nand_chip *chip = mtd_to_nand(mtd);
197 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
198 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
199 	fsl_lbc_t *lbc = ctrl->regs;
200 	u32 timeo = (CONFIG_SYS_HZ * 10) / 1000;
201 	u32 time_start;
202 	u32 ltesr;
203 
204 	/* Setup the FMR[OP] to execute without write protection */
205 	out_be32(&lbc->fmr, priv->fmr | 3);
206 	if (ctrl->use_mdr)
207 		out_be32(&lbc->mdr, ctrl->mdr);
208 
209 	vdbg("fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
210 	     in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
211 	vdbg("fsl_elbc_run_command: fbar=%08x fpar=%08x "
212 	     "fbcr=%08x bank=%d\n",
213 	     in_be32(&lbc->fbar), in_be32(&lbc->fpar),
214 	     in_be32(&lbc->fbcr), priv->bank);
215 
216 	/* execute special operation */
217 	out_be32(&lbc->lsor, priv->bank);
218 
219 	/* wait for FCM complete flag or timeout */
220 	time_start = get_timer(0);
221 
222 	ltesr = 0;
223 	while (get_timer(time_start) < timeo) {
224 		ltesr = in_be32(&lbc->ltesr);
225 		if (ltesr & LTESR_CC)
226 			break;
227 	}
228 
229 	ctrl->status = ltesr & LTESR_NAND_MASK;
230 	out_be32(&lbc->ltesr, ctrl->status);
231 	out_be32(&lbc->lteatr, 0);
232 
233 	/* store mdr value in case it was needed */
234 	if (ctrl->use_mdr)
235 		ctrl->mdr = in_be32(&lbc->mdr);
236 
237 	ctrl->use_mdr = 0;
238 
239 	vdbg("fsl_elbc_run_command: stat=%08x mdr=%08x fmr=%08x\n",
240 	     ctrl->status, ctrl->mdr, in_be32(&lbc->fmr));
241 
242 	/* returns 0 on success otherwise non-zero) */
243 	return ctrl->status == LTESR_CC ? 0 : -EIO;
244 }
245 
246 static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
247 {
248 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
249 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
250 	fsl_lbc_t *lbc = ctrl->regs;
251 
252 	if (priv->page_size) {
253 		out_be32(&lbc->fir,
254 			 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
255 			 (FIR_OP_CA  << FIR_OP1_SHIFT) |
256 			 (FIR_OP_PA  << FIR_OP2_SHIFT) |
257 			 (FIR_OP_CW1 << FIR_OP3_SHIFT) |
258 			 (FIR_OP_RBW << FIR_OP4_SHIFT));
259 
260 		out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
261 				    (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
262 	} else {
263 		out_be32(&lbc->fir,
264 			 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
265 			 (FIR_OP_CA  << FIR_OP1_SHIFT) |
266 			 (FIR_OP_PA  << FIR_OP2_SHIFT) |
267 			 (FIR_OP_RBW << FIR_OP3_SHIFT));
268 
269 		if (oob)
270 			out_be32(&lbc->fcr,
271 				 NAND_CMD_READOOB << FCR_CMD0_SHIFT);
272 		else
273 			out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
274 	}
275 }
276 
277 /* cmdfunc send commands to the FCM */
278 static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
279 			     int column, int page_addr)
280 {
281 	struct nand_chip *chip = mtd_to_nand(mtd);
282 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
283 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
284 	fsl_lbc_t *lbc = ctrl->regs;
285 
286 	ctrl->use_mdr = 0;
287 
288 	/* clear the read buffer */
289 	ctrl->read_bytes = 0;
290 	if (command != NAND_CMD_PAGEPROG)
291 		ctrl->index = 0;
292 
293 	switch (command) {
294 	/* READ0 and READ1 read the entire buffer to use hardware ECC. */
295 	case NAND_CMD_READ1:
296 		column += 256;
297 
298 	/* fall-through */
299 	case NAND_CMD_READ0:
300 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
301 		     " 0x%x, column: 0x%x.\n", page_addr, column);
302 
303 		out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
304 		set_addr(mtd, 0, page_addr, 0);
305 
306 		ctrl->read_bytes = mtd->writesize + mtd->oobsize;
307 		ctrl->index += column;
308 
309 		fsl_elbc_do_read(chip, 0);
310 		fsl_elbc_run_command(mtd);
311 		return;
312 
313 	/* READOOB reads only the OOB because no ECC is performed. */
314 	case NAND_CMD_READOOB:
315 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
316 		     " 0x%x, column: 0x%x.\n", page_addr, column);
317 
318 		out_be32(&lbc->fbcr, mtd->oobsize - column);
319 		set_addr(mtd, column, page_addr, 1);
320 
321 		ctrl->read_bytes = mtd->writesize + mtd->oobsize;
322 
323 		fsl_elbc_do_read(chip, 1);
324 		fsl_elbc_run_command(mtd);
325 
326 		return;
327 
328 	/* READID must read all 5 possible bytes while CEB is active */
329 	case NAND_CMD_READID:
330 	case NAND_CMD_PARAM:
331 		vdbg("fsl_elbc_cmdfunc: NAND_CMD 0x%x.\n", command);
332 
333 		out_be32(&lbc->fir, (FIR_OP_CW0 << FIR_OP0_SHIFT) |
334 				    (FIR_OP_UA  << FIR_OP1_SHIFT) |
335 				    (FIR_OP_RBW << FIR_OP2_SHIFT));
336 		out_be32(&lbc->fcr, command << FCR_CMD0_SHIFT);
337 		/*
338 		 * although currently it's 8 bytes for READID, we always read
339 		 * the maximum 256 bytes(for PARAM)
340 		 */
341 		out_be32(&lbc->fbcr, 256);
342 		ctrl->read_bytes = 256;
343 		ctrl->use_mdr = 1;
344 		ctrl->mdr = column;
345 		set_addr(mtd, 0, 0, 0);
346 		fsl_elbc_run_command(mtd);
347 		return;
348 
349 	/* ERASE1 stores the block and page address */
350 	case NAND_CMD_ERASE1:
351 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
352 		     "page_addr: 0x%x.\n", page_addr);
353 		set_addr(mtd, 0, page_addr, 0);
354 		return;
355 
356 	/* ERASE2 uses the block and page address from ERASE1 */
357 	case NAND_CMD_ERASE2:
358 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");
359 
360 		out_be32(&lbc->fir,
361 			 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
362 			 (FIR_OP_PA  << FIR_OP1_SHIFT) |
363 			 (FIR_OP_CM1 << FIR_OP2_SHIFT));
364 
365 		out_be32(&lbc->fcr,
366 			 (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
367 			 (NAND_CMD_ERASE2 << FCR_CMD1_SHIFT));
368 
369 		out_be32(&lbc->fbcr, 0);
370 		ctrl->read_bytes = 0;
371 
372 		fsl_elbc_run_command(mtd);
373 		return;
374 
375 	/* SEQIN sets up the addr buffer and all registers except the length */
376 	case NAND_CMD_SEQIN: {
377 		u32 fcr;
378 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG, "
379 		     "page_addr: 0x%x, column: 0x%x.\n",
380 		     page_addr, column);
381 
382 		ctrl->column = column;
383 		ctrl->oob = 0;
384 
385 		if (priv->page_size) {
386 			fcr = (NAND_CMD_SEQIN << FCR_CMD0_SHIFT) |
387 			      (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT);
388 
389 			out_be32(&lbc->fir,
390 				 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
391 				 (FIR_OP_CA  << FIR_OP1_SHIFT) |
392 				 (FIR_OP_PA  << FIR_OP2_SHIFT) |
393 				 (FIR_OP_WB  << FIR_OP3_SHIFT) |
394 				 (FIR_OP_CW1 << FIR_OP4_SHIFT));
395 		} else {
396 			fcr = (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT) |
397 			      (NAND_CMD_SEQIN << FCR_CMD2_SHIFT);
398 
399 			out_be32(&lbc->fir,
400 				 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
401 				 (FIR_OP_CM2 << FIR_OP1_SHIFT) |
402 				 (FIR_OP_CA  << FIR_OP2_SHIFT) |
403 				 (FIR_OP_PA  << FIR_OP3_SHIFT) |
404 				 (FIR_OP_WB  << FIR_OP4_SHIFT) |
405 				 (FIR_OP_CW1 << FIR_OP5_SHIFT));
406 
407 			if (column >= mtd->writesize) {
408 				/* OOB area --> READOOB */
409 				column -= mtd->writesize;
410 				fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
411 				ctrl->oob = 1;
412 			} else if (column < 256) {
413 				/* First 256 bytes --> READ0 */
414 				fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
415 			} else {
416 				/* Second 256 bytes --> READ1 */
417 				fcr |= NAND_CMD_READ1 << FCR_CMD0_SHIFT;
418 			}
419 		}
420 
421 		out_be32(&lbc->fcr, fcr);
422 		set_addr(mtd, column, page_addr, ctrl->oob);
423 		return;
424 	}
425 
426 	/* PAGEPROG reuses all of the setup from SEQIN and adds the length */
427 	case NAND_CMD_PAGEPROG: {
428 		vdbg("fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
429 		     "writing %d bytes.\n", ctrl->index);
430 
431 		/* if the write did not start at 0 or is not a full page
432 		 * then set the exact length, otherwise use a full page
433 		 * write so the HW generates the ECC.
434 		 */
435 		if (ctrl->oob || ctrl->column != 0 ||
436 		    ctrl->index != mtd->writesize + mtd->oobsize)
437 			out_be32(&lbc->fbcr, ctrl->index);
438 		else
439 			out_be32(&lbc->fbcr, 0);
440 
441 		fsl_elbc_run_command(mtd);
442 
443 		return;
444 	}
445 
446 	/* CMD_STATUS must read the status byte while CEB is active */
447 	/* Note - it does not wait for the ready line */
448 	case NAND_CMD_STATUS:
449 		out_be32(&lbc->fir,
450 			 (FIR_OP_CM0 << FIR_OP0_SHIFT) |
451 			 (FIR_OP_RBW << FIR_OP1_SHIFT));
452 		out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
453 		out_be32(&lbc->fbcr, 1);
454 		set_addr(mtd, 0, 0, 0);
455 		ctrl->read_bytes = 1;
456 
457 		fsl_elbc_run_command(mtd);
458 
459 		/* The chip always seems to report that it is
460 		 * write-protected, even when it is not.
461 		 */
462 		out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
463 		return;
464 
465 	/* RESET without waiting for the ready line */
466 	case NAND_CMD_RESET:
467 		dbg("fsl_elbc_cmdfunc: NAND_CMD_RESET.\n");
468 		out_be32(&lbc->fir, FIR_OP_CM0 << FIR_OP0_SHIFT);
469 		out_be32(&lbc->fcr, NAND_CMD_RESET << FCR_CMD0_SHIFT);
470 		fsl_elbc_run_command(mtd);
471 		return;
472 
473 	default:
474 		printf("fsl_elbc_cmdfunc: error, unsupported command 0x%x.\n",
475 			command);
476 	}
477 }
478 
479 static void fsl_elbc_select_chip(struct mtd_info *mtd, int chip)
480 {
481 	/* The hardware does not seem to support multiple
482 	 * chips per bank.
483 	 */
484 }
485 
486 /*
487  * Write buf to the FCM Controller Data Buffer
488  */
489 static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
490 {
491 	struct nand_chip *chip = mtd_to_nand(mtd);
492 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
493 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
494 	unsigned int bufsize = mtd->writesize + mtd->oobsize;
495 
496 	if (len <= 0) {
497 		printf("write_buf of %d bytes", len);
498 		ctrl->status = 0;
499 		return;
500 	}
501 
502 	if ((unsigned int)len > bufsize - ctrl->index) {
503 		printf("write_buf beyond end of buffer "
504 		       "(%d requested, %u available)\n",
505 		       len, bufsize - ctrl->index);
506 		len = bufsize - ctrl->index;
507 	}
508 
509 	memcpy_toio(&ctrl->addr[ctrl->index], buf, len);
510 	/*
511 	 * This is workaround for the weird elbc hangs during nand write,
512 	 * Scott Wood says: "...perhaps difference in how long it takes a
513 	 * write to make it through the localbus compared to a write to IMMR
514 	 * is causing problems, and sync isn't helping for some reason."
515 	 * Reading back the last byte helps though.
516 	 */
517 	in_8(&ctrl->addr[ctrl->index] + len - 1);
518 
519 	ctrl->index += len;
520 }
521 
522 /*
523  * read a byte from either the FCM hardware buffer if it has any data left
524  * otherwise issue a command to read a single byte.
525  */
526 static u8 fsl_elbc_read_byte(struct mtd_info *mtd)
527 {
528 	struct nand_chip *chip = mtd_to_nand(mtd);
529 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
530 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
531 
532 	/* If there are still bytes in the FCM, then use the next byte. */
533 	if (ctrl->index < ctrl->read_bytes)
534 		return in_8(&ctrl->addr[ctrl->index++]);
535 
536 	printf("read_byte beyond end of buffer\n");
537 	return ERR_BYTE;
538 }
539 
540 /*
541  * Read from the FCM Controller Data Buffer
542  */
543 static void fsl_elbc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
544 {
545 	struct nand_chip *chip = mtd_to_nand(mtd);
546 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
547 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
548 	int avail;
549 
550 	if (len < 0)
551 		return;
552 
553 	avail = min((unsigned int)len, ctrl->read_bytes - ctrl->index);
554 	memcpy_fromio(buf, &ctrl->addr[ctrl->index], avail);
555 	ctrl->index += avail;
556 
557 	if (len > avail)
558 		printf("read_buf beyond end of buffer "
559 		       "(%d requested, %d available)\n",
560 		       len, avail);
561 }
562 
563 /* This function is called after Program and Erase Operations to
564  * check for success or failure.
565  */
566 static int fsl_elbc_wait(struct mtd_info *mtd, struct nand_chip *chip)
567 {
568 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
569 	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
570 	fsl_lbc_t *lbc = ctrl->regs;
571 
572 	if (ctrl->status != LTESR_CC)
573 		return NAND_STATUS_FAIL;
574 
575 	/* Use READ_STATUS command, but wait for the device to be ready */
576 	ctrl->use_mdr = 0;
577 	out_be32(&lbc->fir,
578 		 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
579 		 (FIR_OP_RBW << FIR_OP1_SHIFT));
580 	out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
581 	out_be32(&lbc->fbcr, 1);
582 	set_addr(mtd, 0, 0, 0);
583 	ctrl->read_bytes = 1;
584 
585 	fsl_elbc_run_command(mtd);
586 
587 	if (ctrl->status != LTESR_CC)
588 		return NAND_STATUS_FAIL;
589 
590 	/* The chip always seems to report that it is
591 	 * write-protected, even when it is not.
592 	 */
593 	out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
594 	return fsl_elbc_read_byte(mtd);
595 }
596 
597 static int fsl_elbc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
598 			      uint8_t *buf, int oob_required, int page)
599 {
600 	fsl_elbc_read_buf(mtd, buf, mtd->writesize);
601 	fsl_elbc_read_buf(mtd, chip->oob_poi, mtd->oobsize);
602 
603 	if (fsl_elbc_wait(mtd, chip) & NAND_STATUS_FAIL)
604 		mtd->ecc_stats.failed++;
605 
606 	return 0;
607 }
608 
609 /* ECC will be calculated automatically, and errors will be detected in
610  * waitfunc.
611  */
612 static int fsl_elbc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
613 				const uint8_t *buf, int oob_required,
614 				int page)
615 {
616 	fsl_elbc_write_buf(mtd, buf, mtd->writesize);
617 	fsl_elbc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
618 
619 	return 0;
620 }
621 
622 static struct fsl_elbc_ctrl *elbc_ctrl;
623 
624 /* ECC will be calculated automatically, and errors will be detected in
625  * waitfunc.
626  */
627 static int fsl_elbc_write_subpage(struct mtd_info *mtd, struct nand_chip *chip,
628 				uint32_t offset, uint32_t data_len,
629 				const uint8_t *buf, int oob_required, int page)
630 {
631 	fsl_elbc_write_buf(mtd, buf, mtd->writesize);
632 	fsl_elbc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
633 
634 	return 0;
635 }
636 
637 static void fsl_elbc_ctrl_init(void)
638 {
639 	elbc_ctrl = kzalloc(sizeof(*elbc_ctrl), GFP_KERNEL);
640 	if (!elbc_ctrl)
641 		return;
642 
643 	elbc_ctrl->regs = LBC_BASE_ADDR;
644 
645 	/* clear event registers */
646 	out_be32(&elbc_ctrl->regs->ltesr, LTESR_NAND_MASK);
647 	out_be32(&elbc_ctrl->regs->lteatr, 0);
648 
649 	/* Enable interrupts for any detected events */
650 	out_be32(&elbc_ctrl->regs->lteir, LTESR_NAND_MASK);
651 
652 	elbc_ctrl->read_bytes = 0;
653 	elbc_ctrl->index = 0;
654 	elbc_ctrl->addr = NULL;
655 }
656 
657 static int fsl_elbc_chip_init(int devnum, u8 *addr)
658 {
659 	struct mtd_info *mtd;
660 	struct nand_chip *nand;
661 	struct fsl_elbc_mtd *priv;
662 	uint32_t br = 0, or = 0;
663 	int ret;
664 
665 	if (!elbc_ctrl) {
666 		fsl_elbc_ctrl_init();
667 		if (!elbc_ctrl)
668 			return -1;
669 	}
670 
671 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
672 	if (!priv)
673 		return -ENOMEM;
674 
675 	priv->ctrl = elbc_ctrl;
676 	priv->vbase = addr;
677 
678 	/* Find which chip select it is connected to.  It'd be nice
679 	 * if we could pass more than one datum to the NAND driver...
680 	 */
681 	for (priv->bank = 0; priv->bank < MAX_BANKS; priv->bank++) {
682 		phys_addr_t phys_addr = virt_to_phys(addr);
683 
684 		br = in_be32(&elbc_ctrl->regs->bank[priv->bank].br);
685 		or = in_be32(&elbc_ctrl->regs->bank[priv->bank].or);
686 
687 		if ((br & BR_V) && (br & BR_MSEL) == BR_MS_FCM &&
688 		    (br & or & BR_BA) == BR_PHYS_ADDR(phys_addr))
689 			break;
690 	}
691 
692 	if (priv->bank >= MAX_BANKS) {
693 		printf("fsl_elbc_nand: address did not match any "
694 		       "chip selects\n");
695 		kfree(priv);
696 		return -ENODEV;
697 	}
698 
699 	nand = &priv->chip;
700 	mtd = nand_to_mtd(nand);
701 
702 	elbc_ctrl->chips[priv->bank] = priv;
703 
704 	/* fill in nand_chip structure */
705 	/* set up function call table */
706 	nand->read_byte = fsl_elbc_read_byte;
707 	nand->write_buf = fsl_elbc_write_buf;
708 	nand->read_buf = fsl_elbc_read_buf;
709 	nand->select_chip = fsl_elbc_select_chip;
710 	nand->cmdfunc = fsl_elbc_cmdfunc;
711 	nand->waitfunc = fsl_elbc_wait;
712 
713 	/* set up nand options */
714 	nand->bbt_td = &bbt_main_descr;
715 	nand->bbt_md = &bbt_mirror_descr;
716 
717   	/* set up nand options */
718 	nand->options = NAND_NO_SUBPAGE_WRITE;
719 	nand->bbt_options = NAND_BBT_USE_FLASH;
720 
721 	nand->controller = &elbc_ctrl->controller;
722 	nand_set_controller_data(nand, priv);
723 
724 	nand->ecc.read_page = fsl_elbc_read_page;
725 	nand->ecc.write_page = fsl_elbc_write_page;
726 	nand->ecc.write_subpage = fsl_elbc_write_subpage;
727 
728 	priv->fmr = (15 << FMR_CWTO_SHIFT) | (2 << FMR_AL_SHIFT);
729 
730 	/* If CS Base Register selects full hardware ECC then use it */
731 	if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
732 		nand->ecc.mode = NAND_ECC_HW;
733 
734 		nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
735 				   &fsl_elbc_oob_sp_eccm1 :
736 				   &fsl_elbc_oob_sp_eccm0;
737 
738 		nand->ecc.size = 512;
739 		nand->ecc.bytes = 3;
740 		nand->ecc.steps = 1;
741 		nand->ecc.strength = 1;
742 	} else {
743 		/* otherwise fall back to software ECC */
744 #if defined(CONFIG_NAND_ECC_BCH)
745 		nand->ecc.mode = NAND_ECC_SOFT_BCH;
746 #else
747 		nand->ecc.mode = NAND_ECC_SOFT;
748 #endif
749 	}
750 
751 	ret = nand_scan_ident(mtd, 1, NULL);
752 	if (ret)
753 		return ret;
754 
755 	/* Large-page-specific setup */
756 	if (mtd->writesize == 2048) {
757 		setbits_be32(&elbc_ctrl->regs->bank[priv->bank].or,
758 			     OR_FCM_PGS);
759 		in_be32(&elbc_ctrl->regs->bank[priv->bank].or);
760 
761 		priv->page_size = 1;
762 		nand->badblock_pattern = &largepage_memorybased;
763 
764 		/*
765 		 * Hardware expects small page has ECCM0, large page has
766 		 * ECCM1 when booting from NAND, and we follow that even
767 		 * when not booting from NAND.
768 		 */
769 		priv->fmr |= FMR_ECCM;
770 
771 		/* adjust ecc setup if needed */
772 		if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
773 			nand->ecc.steps = 4;
774 			nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
775 					   &fsl_elbc_oob_lp_eccm1 :
776 					   &fsl_elbc_oob_lp_eccm0;
777 		}
778 	} else if (mtd->writesize == 512) {
779 		clrbits_be32(&elbc_ctrl->regs->bank[priv->bank].or,
780 			     OR_FCM_PGS);
781 		in_be32(&elbc_ctrl->regs->bank[priv->bank].or);
782 	} else {
783 		return -ENODEV;
784 	}
785 
786 	ret = nand_scan_tail(mtd);
787 	if (ret)
788 		return ret;
789 
790 	ret = nand_register(devnum, mtd);
791 	if (ret)
792 		return ret;
793 
794 	return 0;
795 }
796 
797 #ifndef CONFIG_SYS_NAND_BASE_LIST
798 #define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
799 #endif
800 
801 static unsigned long base_address[CONFIG_SYS_MAX_NAND_DEVICE] =
802 	CONFIG_SYS_NAND_BASE_LIST;
803 
804 void board_nand_init(void)
805 {
806 	int i;
807 
808 	for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
809 		fsl_elbc_chip_init(i, (u8 *)base_address[i]);
810 }
811