xref: /linux/drivers/mtd/nand/raw/fsl_elbc_nand.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Freescale Enhanced Local Bus Controller NAND driver
3  *
4  * Copyright © 2006-2007, 2010 Freescale Semiconductor
5  *
6  * Authors: Nick Spence <nick.spence@freescale.com>,
7  *          Scott Wood <scottwood@freescale.com>
8  *          Jack Lan <jack.lan@freescale.com>
9  *          Roy Zang <tie-fei.zang@freescale.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/ioport.h>
17 #include <linux/of_address.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/interrupt.h>
22 
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/rawnand.h>
25 #include <linux/mtd/nand_ecc.h>
26 #include <linux/mtd/partitions.h>
27 
28 #include <asm/io.h>
29 #include <asm/fsl_lbc.h>
30 
31 #define MAX_BANKS 8
32 #define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */
33 #define FCM_TIMEOUT_MSECS 500 /* Maximum number of mSecs to wait for FCM */
34 
35 /* mtd information per set */
36 
37 struct fsl_elbc_mtd {
38 	struct nand_chip chip;
39 	struct fsl_lbc_ctrl *ctrl;
40 
41 	struct device *dev;
42 	int bank;               /* Chip select bank number           */
43 	u8 __iomem *vbase;      /* Chip select base virtual address  */
44 	int page_size;          /* NAND page size (0=512, 1=2048)    */
45 	unsigned int fmr;       /* FCM Flash Mode Register value     */
46 };
47 
48 /* Freescale eLBC FCM controller information */
49 
50 struct fsl_elbc_fcm_ctrl {
51 	struct nand_controller controller;
52 	struct fsl_elbc_mtd *chips[MAX_BANKS];
53 
54 	u8 __iomem *addr;        /* Address of assigned FCM buffer        */
55 	unsigned int page;       /* Last page written to / read from      */
56 	unsigned int read_bytes; /* Number of bytes read during command   */
57 	unsigned int column;     /* Saved column from SEQIN               */
58 	unsigned int index;      /* Pointer to next byte to 'read'        */
59 	unsigned int status;     /* status read from LTESR after last op  */
60 	unsigned int mdr;        /* UPM/FCM Data Register value           */
61 	unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
62 	unsigned int oob;        /* Non zero if operating on OOB data     */
63 	unsigned int counter;	 /* counter for the initializations	  */
64 	unsigned int max_bitflips;  /* Saved during READ0 cmd		  */
65 };
66 
67 /* These map to the positions used by the FCM hardware ECC generator */
68 
69 static int fsl_elbc_ooblayout_ecc(struct mtd_info *mtd, int section,
70 				  struct mtd_oob_region *oobregion)
71 {
72 	struct nand_chip *chip = mtd_to_nand(mtd);
73 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
74 
75 	if (section >= chip->ecc.steps)
76 		return -ERANGE;
77 
78 	oobregion->offset = (16 * section) + 6;
79 	if (priv->fmr & FMR_ECCM)
80 		oobregion->offset += 2;
81 
82 	oobregion->length = chip->ecc.bytes;
83 
84 	return 0;
85 }
86 
87 static int fsl_elbc_ooblayout_free(struct mtd_info *mtd, int section,
88 				   struct mtd_oob_region *oobregion)
89 {
90 	struct nand_chip *chip = mtd_to_nand(mtd);
91 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
92 
93 	if (section > chip->ecc.steps)
94 		return -ERANGE;
95 
96 	if (!section) {
97 		oobregion->offset = 0;
98 		if (mtd->writesize > 512)
99 			oobregion->offset++;
100 		oobregion->length = (priv->fmr & FMR_ECCM) ? 7 : 5;
101 	} else {
102 		oobregion->offset = (16 * section) -
103 				    ((priv->fmr & FMR_ECCM) ? 5 : 7);
104 		if (section < chip->ecc.steps)
105 			oobregion->length = 13;
106 		else
107 			oobregion->length = mtd->oobsize - oobregion->offset;
108 	}
109 
110 	return 0;
111 }
112 
113 static const struct mtd_ooblayout_ops fsl_elbc_ooblayout_ops = {
114 	.ecc = fsl_elbc_ooblayout_ecc,
115 	.free = fsl_elbc_ooblayout_free,
116 };
117 
118 /*
119  * ELBC may use HW ECC, so that OOB offsets, that NAND core uses for bbt,
120  * interfere with ECC positions, that's why we implement our own descriptors.
121  * OOB {11, 5}, works for both SP and LP chips, with ECCM = 1 and ECCM = 0.
122  */
123 static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
124 static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };
125 
126 static struct nand_bbt_descr bbt_main_descr = {
127 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
128 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
129 	.offs =	11,
130 	.len = 4,
131 	.veroffs = 15,
132 	.maxblocks = 4,
133 	.pattern = bbt_pattern,
134 };
135 
136 static struct nand_bbt_descr bbt_mirror_descr = {
137 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
138 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
139 	.offs =	11,
140 	.len = 4,
141 	.veroffs = 15,
142 	.maxblocks = 4,
143 	.pattern = mirror_pattern,
144 };
145 
146 /*=================================*/
147 
148 /*
149  * Set up the FCM hardware block and page address fields, and the fcm
150  * structure addr field to point to the correct FCM buffer in memory
151  */
152 static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
153 {
154 	struct nand_chip *chip = mtd_to_nand(mtd);
155 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
156 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
157 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
158 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
159 	int buf_num;
160 
161 	elbc_fcm_ctrl->page = page_addr;
162 
163 	if (priv->page_size) {
164 		/*
165 		 * large page size chip : FPAR[PI] save the lowest 6 bits,
166 		 *                        FBAR[BLK] save the other bits.
167 		 */
168 		out_be32(&lbc->fbar, page_addr >> 6);
169 		out_be32(&lbc->fpar,
170 		         ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
171 		         (oob ? FPAR_LP_MS : 0) | column);
172 		buf_num = (page_addr & 1) << 2;
173 	} else {
174 		/*
175 		 * small page size chip : FPAR[PI] save the lowest 5 bits,
176 		 *                        FBAR[BLK] save the other bits.
177 		 */
178 		out_be32(&lbc->fbar, page_addr >> 5);
179 		out_be32(&lbc->fpar,
180 		         ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
181 		         (oob ? FPAR_SP_MS : 0) | column);
182 		buf_num = page_addr & 7;
183 	}
184 
185 	elbc_fcm_ctrl->addr = priv->vbase + buf_num * 1024;
186 	elbc_fcm_ctrl->index = column;
187 
188 	/* for OOB data point to the second half of the buffer */
189 	if (oob)
190 		elbc_fcm_ctrl->index += priv->page_size ? 2048 : 512;
191 
192 	dev_vdbg(priv->dev, "set_addr: bank=%d, "
193 			    "elbc_fcm_ctrl->addr=0x%p (0x%p), "
194 	                    "index %x, pes %d ps %d\n",
195 		 buf_num, elbc_fcm_ctrl->addr, priv->vbase,
196 		 elbc_fcm_ctrl->index,
197 	         chip->phys_erase_shift, chip->page_shift);
198 }
199 
200 /*
201  * execute FCM command and wait for it to complete
202  */
203 static int fsl_elbc_run_command(struct mtd_info *mtd)
204 {
205 	struct nand_chip *chip = mtd_to_nand(mtd);
206 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
207 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
208 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
209 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
210 
211 	/* Setup the FMR[OP] to execute without write protection */
212 	out_be32(&lbc->fmr, priv->fmr | 3);
213 	if (elbc_fcm_ctrl->use_mdr)
214 		out_be32(&lbc->mdr, elbc_fcm_ctrl->mdr);
215 
216 	dev_vdbg(priv->dev,
217 	         "fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
218 	         in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
219 	dev_vdbg(priv->dev,
220 	         "fsl_elbc_run_command: fbar=%08x fpar=%08x "
221 	         "fbcr=%08x bank=%d\n",
222 	         in_be32(&lbc->fbar), in_be32(&lbc->fpar),
223 	         in_be32(&lbc->fbcr), priv->bank);
224 
225 	ctrl->irq_status = 0;
226 	/* execute special operation */
227 	out_be32(&lbc->lsor, priv->bank);
228 
229 	/* wait for FCM complete flag or timeout */
230 	wait_event_timeout(ctrl->irq_wait, ctrl->irq_status,
231 	                   FCM_TIMEOUT_MSECS * HZ/1000);
232 	elbc_fcm_ctrl->status = ctrl->irq_status;
233 	/* store mdr value in case it was needed */
234 	if (elbc_fcm_ctrl->use_mdr)
235 		elbc_fcm_ctrl->mdr = in_be32(&lbc->mdr);
236 
237 	elbc_fcm_ctrl->use_mdr = 0;
238 
239 	if (elbc_fcm_ctrl->status != LTESR_CC) {
240 		dev_info(priv->dev,
241 		         "command failed: fir %x fcr %x status %x mdr %x\n",
242 		         in_be32(&lbc->fir), in_be32(&lbc->fcr),
243 			 elbc_fcm_ctrl->status, elbc_fcm_ctrl->mdr);
244 		return -EIO;
245 	}
246 
247 	if (chip->ecc.mode != NAND_ECC_HW)
248 		return 0;
249 
250 	elbc_fcm_ctrl->max_bitflips = 0;
251 
252 	if (elbc_fcm_ctrl->read_bytes == mtd->writesize + mtd->oobsize) {
253 		uint32_t lteccr = in_be32(&lbc->lteccr);
254 		/*
255 		 * if command was a full page read and the ELBC
256 		 * has the LTECCR register, then bits 12-15 (ppc order) of
257 		 * LTECCR indicates which 512 byte sub-pages had fixed errors.
258 		 * bits 28-31 are uncorrectable errors, marked elsewhere.
259 		 * for small page nand only 1 bit is used.
260 		 * if the ELBC doesn't have the lteccr register it reads 0
261 		 * FIXME: 4 bits can be corrected on NANDs with 2k pages, so
262 		 * count the number of sub-pages with bitflips and update
263 		 * ecc_stats.corrected accordingly.
264 		 */
265 		if (lteccr & 0x000F000F)
266 			out_be32(&lbc->lteccr, 0x000F000F); /* clear lteccr */
267 		if (lteccr & 0x000F0000) {
268 			mtd->ecc_stats.corrected++;
269 			elbc_fcm_ctrl->max_bitflips = 1;
270 		}
271 	}
272 
273 	return 0;
274 }
275 
276 static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
277 {
278 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
279 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
280 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
281 
282 	if (priv->page_size) {
283 		out_be32(&lbc->fir,
284 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
285 		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
286 		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
287 		         (FIR_OP_CM1 << FIR_OP3_SHIFT) |
288 		         (FIR_OP_RBW << FIR_OP4_SHIFT));
289 
290 		out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
291 		                    (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
292 	} else {
293 		out_be32(&lbc->fir,
294 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
295 		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
296 		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
297 		         (FIR_OP_RBW << FIR_OP3_SHIFT));
298 
299 		if (oob)
300 			out_be32(&lbc->fcr, NAND_CMD_READOOB << FCR_CMD0_SHIFT);
301 		else
302 			out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
303 	}
304 }
305 
306 /* cmdfunc send commands to the FCM */
307 static void fsl_elbc_cmdfunc(struct nand_chip *chip, unsigned int command,
308                              int column, int page_addr)
309 {
310 	struct mtd_info *mtd = nand_to_mtd(chip);
311 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
312 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
313 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
314 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
315 
316 	elbc_fcm_ctrl->use_mdr = 0;
317 
318 	/* clear the read buffer */
319 	elbc_fcm_ctrl->read_bytes = 0;
320 	if (command != NAND_CMD_PAGEPROG)
321 		elbc_fcm_ctrl->index = 0;
322 
323 	switch (command) {
324 	/* READ0 and READ1 read the entire buffer to use hardware ECC. */
325 	case NAND_CMD_READ1:
326 		column += 256;
327 		fallthrough;
328 	case NAND_CMD_READ0:
329 		dev_dbg(priv->dev,
330 		        "fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
331 		        " 0x%x, column: 0x%x.\n", page_addr, column);
332 
333 
334 		out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
335 		set_addr(mtd, 0, page_addr, 0);
336 
337 		elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
338 		elbc_fcm_ctrl->index += column;
339 
340 		fsl_elbc_do_read(chip, 0);
341 		fsl_elbc_run_command(mtd);
342 		return;
343 
344 	/* RNDOUT moves the pointer inside the page */
345 	case NAND_CMD_RNDOUT:
346 		dev_dbg(priv->dev,
347 			"fsl_elbc_cmdfunc: NAND_CMD_RNDOUT, column: 0x%x.\n",
348 			column);
349 
350 		elbc_fcm_ctrl->index = column;
351 		return;
352 
353 	/* READOOB reads only the OOB because no ECC is performed. */
354 	case NAND_CMD_READOOB:
355 		dev_vdbg(priv->dev,
356 		         "fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
357 			 " 0x%x, column: 0x%x.\n", page_addr, column);
358 
359 		out_be32(&lbc->fbcr, mtd->oobsize - column);
360 		set_addr(mtd, column, page_addr, 1);
361 
362 		elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
363 
364 		fsl_elbc_do_read(chip, 1);
365 		fsl_elbc_run_command(mtd);
366 		return;
367 
368 	case NAND_CMD_READID:
369 	case NAND_CMD_PARAM:
370 		dev_vdbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD %x\n", command);
371 
372 		out_be32(&lbc->fir, (FIR_OP_CM0 << FIR_OP0_SHIFT) |
373 		                    (FIR_OP_UA  << FIR_OP1_SHIFT) |
374 		                    (FIR_OP_RBW << FIR_OP2_SHIFT));
375 		out_be32(&lbc->fcr, command << FCR_CMD0_SHIFT);
376 		/*
377 		 * although currently it's 8 bytes for READID, we always read
378 		 * the maximum 256 bytes(for PARAM)
379 		 */
380 		out_be32(&lbc->fbcr, 256);
381 		elbc_fcm_ctrl->read_bytes = 256;
382 		elbc_fcm_ctrl->use_mdr = 1;
383 		elbc_fcm_ctrl->mdr = column;
384 		set_addr(mtd, 0, 0, 0);
385 		fsl_elbc_run_command(mtd);
386 		return;
387 
388 	/* ERASE1 stores the block and page address */
389 	case NAND_CMD_ERASE1:
390 		dev_vdbg(priv->dev,
391 		         "fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
392 		         "page_addr: 0x%x.\n", page_addr);
393 		set_addr(mtd, 0, page_addr, 0);
394 		return;
395 
396 	/* ERASE2 uses the block and page address from ERASE1 */
397 	case NAND_CMD_ERASE2:
398 		dev_vdbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");
399 
400 		out_be32(&lbc->fir,
401 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
402 		         (FIR_OP_PA  << FIR_OP1_SHIFT) |
403 		         (FIR_OP_CM2 << FIR_OP2_SHIFT) |
404 		         (FIR_OP_CW1 << FIR_OP3_SHIFT) |
405 		         (FIR_OP_RS  << FIR_OP4_SHIFT));
406 
407 		out_be32(&lbc->fcr,
408 		         (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
409 		         (NAND_CMD_STATUS << FCR_CMD1_SHIFT) |
410 		         (NAND_CMD_ERASE2 << FCR_CMD2_SHIFT));
411 
412 		out_be32(&lbc->fbcr, 0);
413 		elbc_fcm_ctrl->read_bytes = 0;
414 		elbc_fcm_ctrl->use_mdr = 1;
415 
416 		fsl_elbc_run_command(mtd);
417 		return;
418 
419 	/* SEQIN sets up the addr buffer and all registers except the length */
420 	case NAND_CMD_SEQIN: {
421 		__be32 fcr;
422 		dev_vdbg(priv->dev,
423 			 "fsl_elbc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG, "
424 		         "page_addr: 0x%x, column: 0x%x.\n",
425 		         page_addr, column);
426 
427 		elbc_fcm_ctrl->column = column;
428 		elbc_fcm_ctrl->use_mdr = 1;
429 
430 		if (column >= mtd->writesize) {
431 			/* OOB area */
432 			column -= mtd->writesize;
433 			elbc_fcm_ctrl->oob = 1;
434 		} else {
435 			WARN_ON(column != 0);
436 			elbc_fcm_ctrl->oob = 0;
437 		}
438 
439 		fcr = (NAND_CMD_STATUS   << FCR_CMD1_SHIFT) |
440 		      (NAND_CMD_SEQIN    << FCR_CMD2_SHIFT) |
441 		      (NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);
442 
443 		if (priv->page_size) {
444 			out_be32(&lbc->fir,
445 			         (FIR_OP_CM2 << FIR_OP0_SHIFT) |
446 			         (FIR_OP_CA  << FIR_OP1_SHIFT) |
447 			         (FIR_OP_PA  << FIR_OP2_SHIFT) |
448 			         (FIR_OP_WB  << FIR_OP3_SHIFT) |
449 			         (FIR_OP_CM3 << FIR_OP4_SHIFT) |
450 			         (FIR_OP_CW1 << FIR_OP5_SHIFT) |
451 			         (FIR_OP_RS  << FIR_OP6_SHIFT));
452 		} else {
453 			out_be32(&lbc->fir,
454 			         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
455 			         (FIR_OP_CM2 << FIR_OP1_SHIFT) |
456 			         (FIR_OP_CA  << FIR_OP2_SHIFT) |
457 			         (FIR_OP_PA  << FIR_OP3_SHIFT) |
458 			         (FIR_OP_WB  << FIR_OP4_SHIFT) |
459 			         (FIR_OP_CM3 << FIR_OP5_SHIFT) |
460 			         (FIR_OP_CW1 << FIR_OP6_SHIFT) |
461 			         (FIR_OP_RS  << FIR_OP7_SHIFT));
462 
463 			if (elbc_fcm_ctrl->oob)
464 				/* OOB area --> READOOB */
465 				fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
466 			else
467 				/* First 256 bytes --> READ0 */
468 				fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
469 		}
470 
471 		out_be32(&lbc->fcr, fcr);
472 		set_addr(mtd, column, page_addr, elbc_fcm_ctrl->oob);
473 		return;
474 	}
475 
476 	/* PAGEPROG reuses all of the setup from SEQIN and adds the length */
477 	case NAND_CMD_PAGEPROG: {
478 		dev_vdbg(priv->dev,
479 		         "fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
480 			 "writing %d bytes.\n", elbc_fcm_ctrl->index);
481 
482 		/* if the write did not start at 0 or is not a full page
483 		 * then set the exact length, otherwise use a full page
484 		 * write so the HW generates the ECC.
485 		 */
486 		if (elbc_fcm_ctrl->oob || elbc_fcm_ctrl->column != 0 ||
487 		    elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize)
488 			out_be32(&lbc->fbcr,
489 				elbc_fcm_ctrl->index - elbc_fcm_ctrl->column);
490 		else
491 			out_be32(&lbc->fbcr, 0);
492 
493 		fsl_elbc_run_command(mtd);
494 		return;
495 	}
496 
497 	/* CMD_STATUS must read the status byte while CEB is active */
498 	/* Note - it does not wait for the ready line */
499 	case NAND_CMD_STATUS:
500 		out_be32(&lbc->fir,
501 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
502 		         (FIR_OP_RBW << FIR_OP1_SHIFT));
503 		out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
504 		out_be32(&lbc->fbcr, 1);
505 		set_addr(mtd, 0, 0, 0);
506 		elbc_fcm_ctrl->read_bytes = 1;
507 
508 		fsl_elbc_run_command(mtd);
509 
510 		/* The chip always seems to report that it is
511 		 * write-protected, even when it is not.
512 		 */
513 		setbits8(elbc_fcm_ctrl->addr, NAND_STATUS_WP);
514 		return;
515 
516 	/* RESET without waiting for the ready line */
517 	case NAND_CMD_RESET:
518 		dev_dbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD_RESET.\n");
519 		out_be32(&lbc->fir, FIR_OP_CM0 << FIR_OP0_SHIFT);
520 		out_be32(&lbc->fcr, NAND_CMD_RESET << FCR_CMD0_SHIFT);
521 		fsl_elbc_run_command(mtd);
522 		return;
523 
524 	default:
525 		dev_err(priv->dev,
526 		        "fsl_elbc_cmdfunc: error, unsupported command 0x%x.\n",
527 		        command);
528 	}
529 }
530 
531 static void fsl_elbc_select_chip(struct nand_chip *chip, int cs)
532 {
533 	/* The hardware does not seem to support multiple
534 	 * chips per bank.
535 	 */
536 }
537 
538 /*
539  * Write buf to the FCM Controller Data Buffer
540  */
541 static void fsl_elbc_write_buf(struct nand_chip *chip, const u8 *buf, int len)
542 {
543 	struct mtd_info *mtd = nand_to_mtd(chip);
544 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
545 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
546 	unsigned int bufsize = mtd->writesize + mtd->oobsize;
547 
548 	if (len <= 0) {
549 		dev_err(priv->dev, "write_buf of %d bytes", len);
550 		elbc_fcm_ctrl->status = 0;
551 		return;
552 	}
553 
554 	if ((unsigned int)len > bufsize - elbc_fcm_ctrl->index) {
555 		dev_err(priv->dev,
556 		        "write_buf beyond end of buffer "
557 		        "(%d requested, %u available)\n",
558 			len, bufsize - elbc_fcm_ctrl->index);
559 		len = bufsize - elbc_fcm_ctrl->index;
560 	}
561 
562 	memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], buf, len);
563 	/*
564 	 * This is workaround for the weird elbc hangs during nand write,
565 	 * Scott Wood says: "...perhaps difference in how long it takes a
566 	 * write to make it through the localbus compared to a write to IMMR
567 	 * is causing problems, and sync isn't helping for some reason."
568 	 * Reading back the last byte helps though.
569 	 */
570 	in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index] + len - 1);
571 
572 	elbc_fcm_ctrl->index += len;
573 }
574 
575 /*
576  * read a byte from either the FCM hardware buffer if it has any data left
577  * otherwise issue a command to read a single byte.
578  */
579 static u8 fsl_elbc_read_byte(struct nand_chip *chip)
580 {
581 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
582 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
583 
584 	/* If there are still bytes in the FCM, then use the next byte. */
585 	if (elbc_fcm_ctrl->index < elbc_fcm_ctrl->read_bytes)
586 		return in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index++]);
587 
588 	dev_err(priv->dev, "read_byte beyond end of buffer\n");
589 	return ERR_BYTE;
590 }
591 
592 /*
593  * Read from the FCM Controller Data Buffer
594  */
595 static void fsl_elbc_read_buf(struct nand_chip *chip, u8 *buf, int len)
596 {
597 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
598 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
599 	int avail;
600 
601 	if (len < 0)
602 		return;
603 
604 	avail = min((unsigned int)len,
605 			elbc_fcm_ctrl->read_bytes - elbc_fcm_ctrl->index);
606 	memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], avail);
607 	elbc_fcm_ctrl->index += avail;
608 
609 	if (len > avail)
610 		dev_err(priv->dev,
611 		        "read_buf beyond end of buffer "
612 		        "(%d requested, %d available)\n",
613 		        len, avail);
614 }
615 
616 /* This function is called after Program and Erase Operations to
617  * check for success or failure.
618  */
619 static int fsl_elbc_wait(struct nand_chip *chip)
620 {
621 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
622 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
623 
624 	if (elbc_fcm_ctrl->status != LTESR_CC)
625 		return NAND_STATUS_FAIL;
626 
627 	/* The chip always seems to report that it is
628 	 * write-protected, even when it is not.
629 	 */
630 	return (elbc_fcm_ctrl->mdr & 0xff) | NAND_STATUS_WP;
631 }
632 
633 static int fsl_elbc_read_page(struct nand_chip *chip, uint8_t *buf,
634 			      int oob_required, int page)
635 {
636 	struct mtd_info *mtd = nand_to_mtd(chip);
637 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
638 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
639 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
640 
641 	nand_read_page_op(chip, page, 0, buf, mtd->writesize);
642 	if (oob_required)
643 		fsl_elbc_read_buf(chip, chip->oob_poi, mtd->oobsize);
644 
645 	if (fsl_elbc_wait(chip) & NAND_STATUS_FAIL)
646 		mtd->ecc_stats.failed++;
647 
648 	return elbc_fcm_ctrl->max_bitflips;
649 }
650 
651 /* ECC will be calculated automatically, and errors will be detected in
652  * waitfunc.
653  */
654 static int fsl_elbc_write_page(struct nand_chip *chip, const uint8_t *buf,
655 			       int oob_required, int page)
656 {
657 	struct mtd_info *mtd = nand_to_mtd(chip);
658 
659 	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
660 	fsl_elbc_write_buf(chip, chip->oob_poi, mtd->oobsize);
661 
662 	return nand_prog_page_end_op(chip);
663 }
664 
665 /* ECC will be calculated automatically, and errors will be detected in
666  * waitfunc.
667  */
668 static int fsl_elbc_write_subpage(struct nand_chip *chip, uint32_t offset,
669 				  uint32_t data_len, const uint8_t *buf,
670 				  int oob_required, int page)
671 {
672 	struct mtd_info *mtd = nand_to_mtd(chip);
673 
674 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
675 	fsl_elbc_write_buf(chip, buf, mtd->writesize);
676 	fsl_elbc_write_buf(chip, chip->oob_poi, mtd->oobsize);
677 	return nand_prog_page_end_op(chip);
678 }
679 
680 static int fsl_elbc_chip_init(struct fsl_elbc_mtd *priv)
681 {
682 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
683 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
684 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
685 	struct nand_chip *chip = &priv->chip;
686 	struct mtd_info *mtd = nand_to_mtd(chip);
687 
688 	dev_dbg(priv->dev, "eLBC Set Information for bank %d\n", priv->bank);
689 
690 	/* Fill in fsl_elbc_mtd structure */
691 	mtd->dev.parent = priv->dev;
692 	nand_set_flash_node(chip, priv->dev->of_node);
693 
694 	/* set timeout to maximum */
695 	priv->fmr = 15 << FMR_CWTO_SHIFT;
696 	if (in_be32(&lbc->bank[priv->bank].or) & OR_FCM_PGS)
697 		priv->fmr |= FMR_ECCM;
698 
699 	/* fill in nand_chip structure */
700 	/* set up function call table */
701 	chip->legacy.read_byte = fsl_elbc_read_byte;
702 	chip->legacy.write_buf = fsl_elbc_write_buf;
703 	chip->legacy.read_buf = fsl_elbc_read_buf;
704 	chip->legacy.select_chip = fsl_elbc_select_chip;
705 	chip->legacy.cmdfunc = fsl_elbc_cmdfunc;
706 	chip->legacy.waitfunc = fsl_elbc_wait;
707 	chip->legacy.set_features = nand_get_set_features_notsupp;
708 	chip->legacy.get_features = nand_get_set_features_notsupp;
709 
710 	chip->bbt_td = &bbt_main_descr;
711 	chip->bbt_md = &bbt_mirror_descr;
712 
713 	/* set up nand options */
714 	chip->bbt_options = NAND_BBT_USE_FLASH;
715 
716 	chip->controller = &elbc_fcm_ctrl->controller;
717 	nand_set_controller_data(chip, priv);
718 
719 	return 0;
720 }
721 
722 static int fsl_elbc_attach_chip(struct nand_chip *chip)
723 {
724 	struct mtd_info *mtd = nand_to_mtd(chip);
725 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
726 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
727 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
728 	unsigned int al;
729 
730 	switch (chip->ecc.mode) {
731 	/*
732 	 * if ECC was not chosen in DT, decide whether to use HW or SW ECC from
733 	 * CS Base Register
734 	 */
735 	case NAND_ECC_NONE:
736 		/* If CS Base Register selects full hardware ECC then use it */
737 		if ((in_be32(&lbc->bank[priv->bank].br) & BR_DECC) ==
738 		    BR_DECC_CHK_GEN) {
739 			chip->ecc.read_page = fsl_elbc_read_page;
740 			chip->ecc.write_page = fsl_elbc_write_page;
741 			chip->ecc.write_subpage = fsl_elbc_write_subpage;
742 
743 			chip->ecc.mode = NAND_ECC_HW;
744 			mtd_set_ooblayout(mtd, &fsl_elbc_ooblayout_ops);
745 			chip->ecc.size = 512;
746 			chip->ecc.bytes = 3;
747 			chip->ecc.strength = 1;
748 		} else {
749 			/* otherwise fall back to default software ECC */
750 			chip->ecc.mode = NAND_ECC_SOFT;
751 			chip->ecc.algo = NAND_ECC_HAMMING;
752 		}
753 		break;
754 
755 	/* if SW ECC was chosen in DT, we do not need to set anything here */
756 	case NAND_ECC_SOFT:
757 		break;
758 
759 	/* should we also implement NAND_ECC_HW to do as the code above? */
760 	default:
761 		return -EINVAL;
762 	}
763 
764 	/* calculate FMR Address Length field */
765 	al = 0;
766 	if (chip->pagemask & 0xffff0000)
767 		al++;
768 	if (chip->pagemask & 0xff000000)
769 		al++;
770 
771 	priv->fmr |= al << FMR_AL_SHIFT;
772 
773 	dev_dbg(priv->dev, "fsl_elbc_init: nand->numchips = %d\n",
774 	        nanddev_ntargets(&chip->base));
775 	dev_dbg(priv->dev, "fsl_elbc_init: nand->chipsize = %lld\n",
776 	        nanddev_target_size(&chip->base));
777 	dev_dbg(priv->dev, "fsl_elbc_init: nand->pagemask = %8x\n",
778 	        chip->pagemask);
779 	dev_dbg(priv->dev, "fsl_elbc_init: nand->legacy.chip_delay = %d\n",
780 	        chip->legacy.chip_delay);
781 	dev_dbg(priv->dev, "fsl_elbc_init: nand->badblockpos = %d\n",
782 	        chip->badblockpos);
783 	dev_dbg(priv->dev, "fsl_elbc_init: nand->chip_shift = %d\n",
784 	        chip->chip_shift);
785 	dev_dbg(priv->dev, "fsl_elbc_init: nand->page_shift = %d\n",
786 	        chip->page_shift);
787 	dev_dbg(priv->dev, "fsl_elbc_init: nand->phys_erase_shift = %d\n",
788 	        chip->phys_erase_shift);
789 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.mode = %d\n",
790 	        chip->ecc.mode);
791 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.steps = %d\n",
792 	        chip->ecc.steps);
793 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.bytes = %d\n",
794 	        chip->ecc.bytes);
795 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.total = %d\n",
796 	        chip->ecc.total);
797 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->ooblayout = %p\n",
798 		mtd->ooblayout);
799 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->flags = %08x\n", mtd->flags);
800 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->size = %lld\n", mtd->size);
801 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->erasesize = %d\n",
802 	        mtd->erasesize);
803 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->writesize = %d\n",
804 	        mtd->writesize);
805 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->oobsize = %d\n",
806 	        mtd->oobsize);
807 
808 	/* adjust Option Register and ECC to match Flash page size */
809 	if (mtd->writesize == 512) {
810 		priv->page_size = 0;
811 		clrbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
812 	} else if (mtd->writesize == 2048) {
813 		priv->page_size = 1;
814 		setbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
815 	} else {
816 		dev_err(priv->dev,
817 		        "fsl_elbc_init: page size %d is not supported\n",
818 		        mtd->writesize);
819 		return -ENOTSUPP;
820 	}
821 
822 	return 0;
823 }
824 
825 static const struct nand_controller_ops fsl_elbc_controller_ops = {
826 	.attach_chip = fsl_elbc_attach_chip,
827 };
828 
829 static int fsl_elbc_chip_remove(struct fsl_elbc_mtd *priv)
830 {
831 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
832 	struct mtd_info *mtd = nand_to_mtd(&priv->chip);
833 
834 	kfree(mtd->name);
835 
836 	if (priv->vbase)
837 		iounmap(priv->vbase);
838 
839 	elbc_fcm_ctrl->chips[priv->bank] = NULL;
840 	kfree(priv);
841 	return 0;
842 }
843 
844 static DEFINE_MUTEX(fsl_elbc_nand_mutex);
845 
846 static int fsl_elbc_nand_probe(struct platform_device *pdev)
847 {
848 	struct fsl_lbc_regs __iomem *lbc;
849 	struct fsl_elbc_mtd *priv;
850 	struct resource res;
851 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl;
852 	static const char *part_probe_types[]
853 		= { "cmdlinepart", "RedBoot", "ofpart", NULL };
854 	int ret;
855 	int bank;
856 	struct device *dev;
857 	struct device_node *node = pdev->dev.of_node;
858 	struct mtd_info *mtd;
859 
860 	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
861 		return -ENODEV;
862 	lbc = fsl_lbc_ctrl_dev->regs;
863 	dev = fsl_lbc_ctrl_dev->dev;
864 
865 	/* get, allocate and map the memory resource */
866 	ret = of_address_to_resource(node, 0, &res);
867 	if (ret) {
868 		dev_err(dev, "failed to get resource\n");
869 		return ret;
870 	}
871 
872 	/* find which chip select it is connected to */
873 	for (bank = 0; bank < MAX_BANKS; bank++)
874 		if ((in_be32(&lbc->bank[bank].br) & BR_V) &&
875 		    (in_be32(&lbc->bank[bank].br) & BR_MSEL) == BR_MS_FCM &&
876 		    (in_be32(&lbc->bank[bank].br) &
877 		     in_be32(&lbc->bank[bank].or) & BR_BA)
878 		     == fsl_lbc_addr(res.start))
879 			break;
880 
881 	if (bank >= MAX_BANKS) {
882 		dev_err(dev, "address did not match any chip selects\n");
883 		return -ENODEV;
884 	}
885 
886 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
887 	if (!priv)
888 		return -ENOMEM;
889 
890 	mutex_lock(&fsl_elbc_nand_mutex);
891 	if (!fsl_lbc_ctrl_dev->nand) {
892 		elbc_fcm_ctrl = kzalloc(sizeof(*elbc_fcm_ctrl), GFP_KERNEL);
893 		if (!elbc_fcm_ctrl) {
894 			mutex_unlock(&fsl_elbc_nand_mutex);
895 			ret = -ENOMEM;
896 			goto err;
897 		}
898 		elbc_fcm_ctrl->counter++;
899 
900 		nand_controller_init(&elbc_fcm_ctrl->controller);
901 		fsl_lbc_ctrl_dev->nand = elbc_fcm_ctrl;
902 	} else {
903 		elbc_fcm_ctrl = fsl_lbc_ctrl_dev->nand;
904 	}
905 	mutex_unlock(&fsl_elbc_nand_mutex);
906 
907 	elbc_fcm_ctrl->chips[bank] = priv;
908 	priv->bank = bank;
909 	priv->ctrl = fsl_lbc_ctrl_dev;
910 	priv->dev = &pdev->dev;
911 	dev_set_drvdata(priv->dev, priv);
912 
913 	priv->vbase = ioremap(res.start, resource_size(&res));
914 	if (!priv->vbase) {
915 		dev_err(dev, "failed to map chip region\n");
916 		ret = -ENOMEM;
917 		goto err;
918 	}
919 
920 	mtd = nand_to_mtd(&priv->chip);
921 	mtd->name = kasprintf(GFP_KERNEL, "%llx.flash", (u64)res.start);
922 	if (!nand_to_mtd(&priv->chip)->name) {
923 		ret = -ENOMEM;
924 		goto err;
925 	}
926 
927 	ret = fsl_elbc_chip_init(priv);
928 	if (ret)
929 		goto err;
930 
931 	priv->chip.controller->ops = &fsl_elbc_controller_ops;
932 	ret = nand_scan(&priv->chip, 1);
933 	if (ret)
934 		goto err;
935 
936 	/* First look for RedBoot table or partitions on the command
937 	 * line, these take precedence over device tree information */
938 	ret = mtd_device_parse_register(mtd, part_probe_types, NULL, NULL, 0);
939 	if (ret)
940 		goto cleanup_nand;
941 
942 	pr_info("eLBC NAND device at 0x%llx, bank %d\n",
943 		(unsigned long long)res.start, priv->bank);
944 
945 	return 0;
946 
947 cleanup_nand:
948 	nand_cleanup(&priv->chip);
949 err:
950 	fsl_elbc_chip_remove(priv);
951 
952 	return ret;
953 }
954 
955 static int fsl_elbc_nand_remove(struct platform_device *pdev)
956 {
957 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = fsl_lbc_ctrl_dev->nand;
958 	struct fsl_elbc_mtd *priv = dev_get_drvdata(&pdev->dev);
959 
960 	nand_release(&priv->chip);
961 	fsl_elbc_chip_remove(priv);
962 
963 	mutex_lock(&fsl_elbc_nand_mutex);
964 	elbc_fcm_ctrl->counter--;
965 	if (!elbc_fcm_ctrl->counter) {
966 		fsl_lbc_ctrl_dev->nand = NULL;
967 		kfree(elbc_fcm_ctrl);
968 	}
969 	mutex_unlock(&fsl_elbc_nand_mutex);
970 
971 	return 0;
972 
973 }
974 
975 static const struct of_device_id fsl_elbc_nand_match[] = {
976 	{ .compatible = "fsl,elbc-fcm-nand", },
977 	{}
978 };
979 MODULE_DEVICE_TABLE(of, fsl_elbc_nand_match);
980 
981 static struct platform_driver fsl_elbc_nand_driver = {
982 	.driver = {
983 		.name = "fsl,elbc-fcm-nand",
984 		.of_match_table = fsl_elbc_nand_match,
985 	},
986 	.probe = fsl_elbc_nand_probe,
987 	.remove = fsl_elbc_nand_remove,
988 };
989 
990 module_platform_driver(fsl_elbc_nand_driver);
991 
992 MODULE_LICENSE("GPL");
993 MODULE_AUTHOR("Freescale");
994 MODULE_DESCRIPTION("Freescale Enhanced Local Bus Controller MTD NAND driver");
995