xref: /linux/drivers/mtd/nand/raw/fsl_elbc_nand.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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/partitions.h>
26 
27 #include <asm/io.h>
28 #include <asm/fsl_lbc.h>
29 
30 #define MAX_BANKS 8
31 #define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */
32 #define FCM_TIMEOUT_MSECS 500 /* Maximum number of mSecs to wait for FCM */
33 
34 /* mtd information per set */
35 
36 struct fsl_elbc_mtd {
37 	struct nand_chip chip;
38 	struct fsl_lbc_ctrl *ctrl;
39 
40 	struct device *dev;
41 	int bank;               /* Chip select bank number           */
42 	u8 __iomem *vbase;      /* Chip select base virtual address  */
43 	int page_size;          /* NAND page size (0=512, 1=2048)    */
44 	unsigned int fmr;       /* FCM Flash Mode Register value     */
45 };
46 
47 /* Freescale eLBC FCM controller information */
48 
49 struct fsl_elbc_fcm_ctrl {
50 	struct nand_controller controller;
51 	struct fsl_elbc_mtd *chips[MAX_BANKS];
52 
53 	u8 __iomem *addr;        /* Address of assigned FCM buffer        */
54 	unsigned int page;       /* Last page written to / read from      */
55 	unsigned int read_bytes; /* Number of bytes read during command   */
56 	unsigned int column;     /* Saved column from SEQIN               */
57 	unsigned int index;      /* Pointer to next byte to 'read'        */
58 	unsigned int status;     /* status read from LTESR after last op  */
59 	unsigned int mdr;        /* UPM/FCM Data Register value           */
60 	unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
61 	unsigned int oob;        /* Non zero if operating on OOB data     */
62 	unsigned int counter;	 /* counter for the initializations	  */
63 	unsigned int max_bitflips;  /* Saved during READ0 cmd		  */
64 };
65 
66 /* These map to the positions used by the FCM hardware ECC generator */
67 
68 static int fsl_elbc_ooblayout_ecc(struct mtd_info *mtd, int section,
69 				  struct mtd_oob_region *oobregion)
70 {
71 	struct nand_chip *chip = mtd_to_nand(mtd);
72 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
73 
74 	if (section >= chip->ecc.steps)
75 		return -ERANGE;
76 
77 	oobregion->offset = (16 * section) + 6;
78 	if (priv->fmr & FMR_ECCM)
79 		oobregion->offset += 2;
80 
81 	oobregion->length = chip->ecc.bytes;
82 
83 	return 0;
84 }
85 
86 static int fsl_elbc_ooblayout_free(struct mtd_info *mtd, int section,
87 				   struct mtd_oob_region *oobregion)
88 {
89 	struct nand_chip *chip = mtd_to_nand(mtd);
90 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
91 
92 	if (section > chip->ecc.steps)
93 		return -ERANGE;
94 
95 	if (!section) {
96 		oobregion->offset = 0;
97 		if (mtd->writesize > 512)
98 			oobregion->offset++;
99 		oobregion->length = (priv->fmr & FMR_ECCM) ? 7 : 5;
100 	} else {
101 		oobregion->offset = (16 * section) -
102 				    ((priv->fmr & FMR_ECCM) ? 5 : 7);
103 		if (section < chip->ecc.steps)
104 			oobregion->length = 13;
105 		else
106 			oobregion->length = mtd->oobsize - oobregion->offset;
107 	}
108 
109 	return 0;
110 }
111 
112 static const struct mtd_ooblayout_ops fsl_elbc_ooblayout_ops = {
113 	.ecc = fsl_elbc_ooblayout_ecc,
114 	.free = fsl_elbc_ooblayout_free,
115 };
116 
117 /*
118  * ELBC may use HW ECC, so that OOB offsets, that NAND core uses for bbt,
119  * interfere with ECC positions, that's why we implement our own descriptors.
120  * OOB {11, 5}, works for both SP and LP chips, with ECCM = 1 and ECCM = 0.
121  */
122 static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
123 static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };
124 
125 static struct nand_bbt_descr bbt_main_descr = {
126 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
127 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
128 	.offs =	11,
129 	.len = 4,
130 	.veroffs = 15,
131 	.maxblocks = 4,
132 	.pattern = bbt_pattern,
133 };
134 
135 static struct nand_bbt_descr bbt_mirror_descr = {
136 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
137 		   NAND_BBT_2BIT | NAND_BBT_VERSION,
138 	.offs =	11,
139 	.len = 4,
140 	.veroffs = 15,
141 	.maxblocks = 4,
142 	.pattern = mirror_pattern,
143 };
144 
145 /*=================================*/
146 
147 /*
148  * Set up the FCM hardware block and page address fields, and the fcm
149  * structure addr field to point to the correct FCM buffer in memory
150  */
151 static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
152 {
153 	struct nand_chip *chip = mtd_to_nand(mtd);
154 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
155 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
156 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
157 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
158 	int buf_num;
159 
160 	elbc_fcm_ctrl->page = page_addr;
161 
162 	if (priv->page_size) {
163 		/*
164 		 * large page size chip : FPAR[PI] save the lowest 6 bits,
165 		 *                        FBAR[BLK] save the other bits.
166 		 */
167 		out_be32(&lbc->fbar, page_addr >> 6);
168 		out_be32(&lbc->fpar,
169 		         ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
170 		         (oob ? FPAR_LP_MS : 0) | column);
171 		buf_num = (page_addr & 1) << 2;
172 	} else {
173 		/*
174 		 * small page size chip : FPAR[PI] save the lowest 5 bits,
175 		 *                        FBAR[BLK] save the other bits.
176 		 */
177 		out_be32(&lbc->fbar, page_addr >> 5);
178 		out_be32(&lbc->fpar,
179 		         ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
180 		         (oob ? FPAR_SP_MS : 0) | column);
181 		buf_num = page_addr & 7;
182 	}
183 
184 	elbc_fcm_ctrl->addr = priv->vbase + buf_num * 1024;
185 	elbc_fcm_ctrl->index = column;
186 
187 	/* for OOB data point to the second half of the buffer */
188 	if (oob)
189 		elbc_fcm_ctrl->index += priv->page_size ? 2048 : 512;
190 
191 	dev_vdbg(priv->dev, "set_addr: bank=%d, "
192 			    "elbc_fcm_ctrl->addr=0x%p (0x%p), "
193 	                    "index %x, pes %d ps %d\n",
194 		 buf_num, elbc_fcm_ctrl->addr, priv->vbase,
195 		 elbc_fcm_ctrl->index,
196 	         chip->phys_erase_shift, chip->page_shift);
197 }
198 
199 /*
200  * execute FCM command and wait for it to complete
201  */
202 static int fsl_elbc_run_command(struct mtd_info *mtd)
203 {
204 	struct nand_chip *chip = mtd_to_nand(mtd);
205 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
206 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
207 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
208 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
209 
210 	/* Setup the FMR[OP] to execute without write protection */
211 	out_be32(&lbc->fmr, priv->fmr | 3);
212 	if (elbc_fcm_ctrl->use_mdr)
213 		out_be32(&lbc->mdr, elbc_fcm_ctrl->mdr);
214 
215 	dev_vdbg(priv->dev,
216 	         "fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
217 	         in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
218 	dev_vdbg(priv->dev,
219 	         "fsl_elbc_run_command: fbar=%08x fpar=%08x "
220 	         "fbcr=%08x bank=%d\n",
221 	         in_be32(&lbc->fbar), in_be32(&lbc->fpar),
222 	         in_be32(&lbc->fbcr), priv->bank);
223 
224 	ctrl->irq_status = 0;
225 	/* execute special operation */
226 	out_be32(&lbc->lsor, priv->bank);
227 
228 	/* wait for FCM complete flag or timeout */
229 	wait_event_timeout(ctrl->irq_wait, ctrl->irq_status,
230 	                   FCM_TIMEOUT_MSECS * HZ/1000);
231 	elbc_fcm_ctrl->status = ctrl->irq_status;
232 	/* store mdr value in case it was needed */
233 	if (elbc_fcm_ctrl->use_mdr)
234 		elbc_fcm_ctrl->mdr = in_be32(&lbc->mdr);
235 
236 	elbc_fcm_ctrl->use_mdr = 0;
237 
238 	if (elbc_fcm_ctrl->status != LTESR_CC) {
239 		dev_info(priv->dev,
240 		         "command failed: fir %x fcr %x status %x mdr %x\n",
241 		         in_be32(&lbc->fir), in_be32(&lbc->fcr),
242 			 elbc_fcm_ctrl->status, elbc_fcm_ctrl->mdr);
243 		return -EIO;
244 	}
245 
246 	if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
247 		return 0;
248 
249 	elbc_fcm_ctrl->max_bitflips = 0;
250 
251 	if (elbc_fcm_ctrl->read_bytes == mtd->writesize + mtd->oobsize) {
252 		uint32_t lteccr = in_be32(&lbc->lteccr);
253 		/*
254 		 * if command was a full page read and the ELBC
255 		 * has the LTECCR register, then bits 12-15 (ppc order) of
256 		 * LTECCR indicates which 512 byte sub-pages had fixed errors.
257 		 * bits 28-31 are uncorrectable errors, marked elsewhere.
258 		 * for small page nand only 1 bit is used.
259 		 * if the ELBC doesn't have the lteccr register it reads 0
260 		 * FIXME: 4 bits can be corrected on NANDs with 2k pages, so
261 		 * count the number of sub-pages with bitflips and update
262 		 * ecc_stats.corrected accordingly.
263 		 */
264 		if (lteccr & 0x000F000F)
265 			out_be32(&lbc->lteccr, 0x000F000F); /* clear lteccr */
266 		if (lteccr & 0x000F0000) {
267 			mtd->ecc_stats.corrected++;
268 			elbc_fcm_ctrl->max_bitflips = 1;
269 		}
270 	}
271 
272 	return 0;
273 }
274 
275 static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
276 {
277 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
278 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
279 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
280 
281 	if (priv->page_size) {
282 		out_be32(&lbc->fir,
283 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
284 		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
285 		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
286 		         (FIR_OP_CM1 << FIR_OP3_SHIFT) |
287 		         (FIR_OP_RBW << FIR_OP4_SHIFT));
288 
289 		out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
290 		                    (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
291 	} else {
292 		out_be32(&lbc->fir,
293 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
294 		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
295 		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
296 		         (FIR_OP_RBW << FIR_OP3_SHIFT));
297 
298 		if (oob)
299 			out_be32(&lbc->fcr, NAND_CMD_READOOB << FCR_CMD0_SHIFT);
300 		else
301 			out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
302 	}
303 }
304 
305 /* cmdfunc send commands to the FCM */
306 static void fsl_elbc_cmdfunc(struct nand_chip *chip, unsigned int command,
307                              int column, int page_addr)
308 {
309 	struct mtd_info *mtd = nand_to_mtd(chip);
310 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
311 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
312 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
313 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
314 
315 	elbc_fcm_ctrl->use_mdr = 0;
316 
317 	/* clear the read buffer */
318 	elbc_fcm_ctrl->read_bytes = 0;
319 	if (command != NAND_CMD_PAGEPROG)
320 		elbc_fcm_ctrl->index = 0;
321 
322 	switch (command) {
323 	/* READ0 and READ1 read the entire buffer to use hardware ECC. */
324 	case NAND_CMD_READ1:
325 		column += 256;
326 		fallthrough;
327 	case NAND_CMD_READ0:
328 		dev_dbg(priv->dev,
329 		        "fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
330 		        " 0x%x, column: 0x%x.\n", page_addr, column);
331 
332 
333 		out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
334 		set_addr(mtd, 0, page_addr, 0);
335 
336 		elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
337 		elbc_fcm_ctrl->index += column;
338 
339 		fsl_elbc_do_read(chip, 0);
340 		fsl_elbc_run_command(mtd);
341 		return;
342 
343 	/* RNDOUT moves the pointer inside the page */
344 	case NAND_CMD_RNDOUT:
345 		dev_dbg(priv->dev,
346 			"fsl_elbc_cmdfunc: NAND_CMD_RNDOUT, column: 0x%x.\n",
347 			column);
348 
349 		elbc_fcm_ctrl->index = column;
350 		return;
351 
352 	/* READOOB reads only the OOB because no ECC is performed. */
353 	case NAND_CMD_READOOB:
354 		dev_vdbg(priv->dev,
355 		         "fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
356 			 " 0x%x, column: 0x%x.\n", page_addr, column);
357 
358 		out_be32(&lbc->fbcr, mtd->oobsize - column);
359 		set_addr(mtd, column, page_addr, 1);
360 
361 		elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
362 
363 		fsl_elbc_do_read(chip, 1);
364 		fsl_elbc_run_command(mtd);
365 		return;
366 
367 	case NAND_CMD_READID:
368 	case NAND_CMD_PARAM:
369 		dev_vdbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD %x\n", command);
370 
371 		out_be32(&lbc->fir, (FIR_OP_CM0 << FIR_OP0_SHIFT) |
372 		                    (FIR_OP_UA  << FIR_OP1_SHIFT) |
373 		                    (FIR_OP_RBW << FIR_OP2_SHIFT));
374 		out_be32(&lbc->fcr, command << FCR_CMD0_SHIFT);
375 		/*
376 		 * although currently it's 8 bytes for READID, we always read
377 		 * the maximum 256 bytes(for PARAM)
378 		 */
379 		out_be32(&lbc->fbcr, 256);
380 		elbc_fcm_ctrl->read_bytes = 256;
381 		elbc_fcm_ctrl->use_mdr = 1;
382 		elbc_fcm_ctrl->mdr = column;
383 		set_addr(mtd, 0, 0, 0);
384 		fsl_elbc_run_command(mtd);
385 		return;
386 
387 	/* ERASE1 stores the block and page address */
388 	case NAND_CMD_ERASE1:
389 		dev_vdbg(priv->dev,
390 		         "fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
391 		         "page_addr: 0x%x.\n", page_addr);
392 		set_addr(mtd, 0, page_addr, 0);
393 		return;
394 
395 	/* ERASE2 uses the block and page address from ERASE1 */
396 	case NAND_CMD_ERASE2:
397 		dev_vdbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");
398 
399 		out_be32(&lbc->fir,
400 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
401 		         (FIR_OP_PA  << FIR_OP1_SHIFT) |
402 		         (FIR_OP_CM2 << FIR_OP2_SHIFT) |
403 		         (FIR_OP_CW1 << FIR_OP3_SHIFT) |
404 		         (FIR_OP_RS  << FIR_OP4_SHIFT));
405 
406 		out_be32(&lbc->fcr,
407 		         (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
408 		         (NAND_CMD_STATUS << FCR_CMD1_SHIFT) |
409 		         (NAND_CMD_ERASE2 << FCR_CMD2_SHIFT));
410 
411 		out_be32(&lbc->fbcr, 0);
412 		elbc_fcm_ctrl->read_bytes = 0;
413 		elbc_fcm_ctrl->use_mdr = 1;
414 
415 		fsl_elbc_run_command(mtd);
416 		return;
417 
418 	/* SEQIN sets up the addr buffer and all registers except the length */
419 	case NAND_CMD_SEQIN: {
420 		__be32 fcr;
421 		dev_vdbg(priv->dev,
422 			 "fsl_elbc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG, "
423 		         "page_addr: 0x%x, column: 0x%x.\n",
424 		         page_addr, column);
425 
426 		elbc_fcm_ctrl->column = column;
427 		elbc_fcm_ctrl->use_mdr = 1;
428 
429 		if (column >= mtd->writesize) {
430 			/* OOB area */
431 			column -= mtd->writesize;
432 			elbc_fcm_ctrl->oob = 1;
433 		} else {
434 			WARN_ON(column != 0);
435 			elbc_fcm_ctrl->oob = 0;
436 		}
437 
438 		fcr = (NAND_CMD_STATUS   << FCR_CMD1_SHIFT) |
439 		      (NAND_CMD_SEQIN    << FCR_CMD2_SHIFT) |
440 		      (NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);
441 
442 		if (priv->page_size) {
443 			out_be32(&lbc->fir,
444 			         (FIR_OP_CM2 << FIR_OP0_SHIFT) |
445 			         (FIR_OP_CA  << FIR_OP1_SHIFT) |
446 			         (FIR_OP_PA  << FIR_OP2_SHIFT) |
447 			         (FIR_OP_WB  << FIR_OP3_SHIFT) |
448 			         (FIR_OP_CM3 << FIR_OP4_SHIFT) |
449 			         (FIR_OP_CW1 << FIR_OP5_SHIFT) |
450 			         (FIR_OP_RS  << FIR_OP6_SHIFT));
451 		} else {
452 			out_be32(&lbc->fir,
453 			         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
454 			         (FIR_OP_CM2 << FIR_OP1_SHIFT) |
455 			         (FIR_OP_CA  << FIR_OP2_SHIFT) |
456 			         (FIR_OP_PA  << FIR_OP3_SHIFT) |
457 			         (FIR_OP_WB  << FIR_OP4_SHIFT) |
458 			         (FIR_OP_CM3 << FIR_OP5_SHIFT) |
459 			         (FIR_OP_CW1 << FIR_OP6_SHIFT) |
460 			         (FIR_OP_RS  << FIR_OP7_SHIFT));
461 
462 			if (elbc_fcm_ctrl->oob)
463 				/* OOB area --> READOOB */
464 				fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
465 			else
466 				/* First 256 bytes --> READ0 */
467 				fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
468 		}
469 
470 		out_be32(&lbc->fcr, fcr);
471 		set_addr(mtd, column, page_addr, elbc_fcm_ctrl->oob);
472 		return;
473 	}
474 
475 	/* PAGEPROG reuses all of the setup from SEQIN and adds the length */
476 	case NAND_CMD_PAGEPROG: {
477 		dev_vdbg(priv->dev,
478 		         "fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
479 			 "writing %d bytes.\n", elbc_fcm_ctrl->index);
480 
481 		/* if the write did not start at 0 or is not a full page
482 		 * then set the exact length, otherwise use a full page
483 		 * write so the HW generates the ECC.
484 		 */
485 		if (elbc_fcm_ctrl->oob || elbc_fcm_ctrl->column != 0 ||
486 		    elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize)
487 			out_be32(&lbc->fbcr,
488 				elbc_fcm_ctrl->index - elbc_fcm_ctrl->column);
489 		else
490 			out_be32(&lbc->fbcr, 0);
491 
492 		fsl_elbc_run_command(mtd);
493 		return;
494 	}
495 
496 	/* CMD_STATUS must read the status byte while CEB is active */
497 	/* Note - it does not wait for the ready line */
498 	case NAND_CMD_STATUS:
499 		out_be32(&lbc->fir,
500 		         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
501 		         (FIR_OP_RBW << FIR_OP1_SHIFT));
502 		out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
503 		out_be32(&lbc->fbcr, 1);
504 		set_addr(mtd, 0, 0, 0);
505 		elbc_fcm_ctrl->read_bytes = 1;
506 
507 		fsl_elbc_run_command(mtd);
508 
509 		/* The chip always seems to report that it is
510 		 * write-protected, even when it is not.
511 		 */
512 		setbits8(elbc_fcm_ctrl->addr, NAND_STATUS_WP);
513 		return;
514 
515 	/* RESET without waiting for the ready line */
516 	case NAND_CMD_RESET:
517 		dev_dbg(priv->dev, "fsl_elbc_cmdfunc: NAND_CMD_RESET.\n");
518 		out_be32(&lbc->fir, FIR_OP_CM0 << FIR_OP0_SHIFT);
519 		out_be32(&lbc->fcr, NAND_CMD_RESET << FCR_CMD0_SHIFT);
520 		fsl_elbc_run_command(mtd);
521 		return;
522 
523 	default:
524 		dev_err(priv->dev,
525 		        "fsl_elbc_cmdfunc: error, unsupported command 0x%x.\n",
526 		        command);
527 	}
528 }
529 
530 static void fsl_elbc_select_chip(struct nand_chip *chip, int cs)
531 {
532 	/* The hardware does not seem to support multiple
533 	 * chips per bank.
534 	 */
535 }
536 
537 /*
538  * Write buf to the FCM Controller Data Buffer
539  */
540 static void fsl_elbc_write_buf(struct nand_chip *chip, const u8 *buf, int len)
541 {
542 	struct mtd_info *mtd = nand_to_mtd(chip);
543 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
544 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
545 	unsigned int bufsize = mtd->writesize + mtd->oobsize;
546 
547 	if (len <= 0) {
548 		dev_err(priv->dev, "write_buf of %d bytes", len);
549 		elbc_fcm_ctrl->status = 0;
550 		return;
551 	}
552 
553 	if ((unsigned int)len > bufsize - elbc_fcm_ctrl->index) {
554 		dev_err(priv->dev,
555 		        "write_buf beyond end of buffer "
556 		        "(%d requested, %u available)\n",
557 			len, bufsize - elbc_fcm_ctrl->index);
558 		len = bufsize - elbc_fcm_ctrl->index;
559 	}
560 
561 	memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], buf, len);
562 	/*
563 	 * This is workaround for the weird elbc hangs during nand write,
564 	 * Scott Wood says: "...perhaps difference in how long it takes a
565 	 * write to make it through the localbus compared to a write to IMMR
566 	 * is causing problems, and sync isn't helping for some reason."
567 	 * Reading back the last byte helps though.
568 	 */
569 	in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index] + len - 1);
570 
571 	elbc_fcm_ctrl->index += len;
572 }
573 
574 /*
575  * read a byte from either the FCM hardware buffer if it has any data left
576  * otherwise issue a command to read a single byte.
577  */
578 static u8 fsl_elbc_read_byte(struct nand_chip *chip)
579 {
580 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
581 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
582 
583 	/* If there are still bytes in the FCM, then use the next byte. */
584 	if (elbc_fcm_ctrl->index < elbc_fcm_ctrl->read_bytes)
585 		return in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index++]);
586 
587 	dev_err(priv->dev, "read_byte beyond end of buffer\n");
588 	return ERR_BYTE;
589 }
590 
591 /*
592  * Read from the FCM Controller Data Buffer
593  */
594 static void fsl_elbc_read_buf(struct nand_chip *chip, u8 *buf, int len)
595 {
596 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
597 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
598 	int avail;
599 
600 	if (len < 0)
601 		return;
602 
603 	avail = min((unsigned int)len,
604 			elbc_fcm_ctrl->read_bytes - elbc_fcm_ctrl->index);
605 	memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], avail);
606 	elbc_fcm_ctrl->index += avail;
607 
608 	if (len > avail)
609 		dev_err(priv->dev,
610 		        "read_buf beyond end of buffer "
611 		        "(%d requested, %d available)\n",
612 		        len, avail);
613 }
614 
615 /* This function is called after Program and Erase Operations to
616  * check for success or failure.
617  */
618 static int fsl_elbc_wait(struct nand_chip *chip)
619 {
620 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
621 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
622 
623 	if (elbc_fcm_ctrl->status != LTESR_CC)
624 		return NAND_STATUS_FAIL;
625 
626 	/* The chip always seems to report that it is
627 	 * write-protected, even when it is not.
628 	 */
629 	return (elbc_fcm_ctrl->mdr & 0xff) | NAND_STATUS_WP;
630 }
631 
632 static int fsl_elbc_read_page(struct nand_chip *chip, uint8_t *buf,
633 			      int oob_required, int page)
634 {
635 	struct mtd_info *mtd = nand_to_mtd(chip);
636 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
637 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
638 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
639 
640 	nand_read_page_op(chip, page, 0, buf, mtd->writesize);
641 	if (oob_required)
642 		fsl_elbc_read_buf(chip, chip->oob_poi, mtd->oobsize);
643 
644 	if (fsl_elbc_wait(chip) & NAND_STATUS_FAIL)
645 		mtd->ecc_stats.failed++;
646 
647 	return elbc_fcm_ctrl->max_bitflips;
648 }
649 
650 /* ECC will be calculated automatically, and errors will be detected in
651  * waitfunc.
652  */
653 static int fsl_elbc_write_page(struct nand_chip *chip, const uint8_t *buf,
654 			       int oob_required, int page)
655 {
656 	struct mtd_info *mtd = nand_to_mtd(chip);
657 
658 	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
659 	fsl_elbc_write_buf(chip, chip->oob_poi, mtd->oobsize);
660 
661 	return nand_prog_page_end_op(chip);
662 }
663 
664 /* ECC will be calculated automatically, and errors will be detected in
665  * waitfunc.
666  */
667 static int fsl_elbc_write_subpage(struct nand_chip *chip, uint32_t offset,
668 				  uint32_t data_len, const uint8_t *buf,
669 				  int oob_required, int page)
670 {
671 	struct mtd_info *mtd = nand_to_mtd(chip);
672 
673 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
674 	fsl_elbc_write_buf(chip, buf, mtd->writesize);
675 	fsl_elbc_write_buf(chip, chip->oob_poi, mtd->oobsize);
676 	return nand_prog_page_end_op(chip);
677 }
678 
679 static int fsl_elbc_chip_init(struct fsl_elbc_mtd *priv)
680 {
681 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
682 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
683 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
684 	struct nand_chip *chip = &priv->chip;
685 	struct mtd_info *mtd = nand_to_mtd(chip);
686 
687 	dev_dbg(priv->dev, "eLBC Set Information for bank %d\n", priv->bank);
688 
689 	/* Fill in fsl_elbc_mtd structure */
690 	mtd->dev.parent = priv->dev;
691 	nand_set_flash_node(chip, priv->dev->of_node);
692 
693 	/* set timeout to maximum */
694 	priv->fmr = 15 << FMR_CWTO_SHIFT;
695 	if (in_be32(&lbc->bank[priv->bank].or) & OR_FCM_PGS)
696 		priv->fmr |= FMR_ECCM;
697 
698 	/* fill in nand_chip structure */
699 	/* set up function call table */
700 	chip->legacy.read_byte = fsl_elbc_read_byte;
701 	chip->legacy.write_buf = fsl_elbc_write_buf;
702 	chip->legacy.read_buf = fsl_elbc_read_buf;
703 	chip->legacy.select_chip = fsl_elbc_select_chip;
704 	chip->legacy.cmdfunc = fsl_elbc_cmdfunc;
705 	chip->legacy.waitfunc = fsl_elbc_wait;
706 	chip->legacy.set_features = nand_get_set_features_notsupp;
707 	chip->legacy.get_features = nand_get_set_features_notsupp;
708 
709 	chip->bbt_td = &bbt_main_descr;
710 	chip->bbt_md = &bbt_mirror_descr;
711 
712 	/* set up nand options */
713 	chip->bbt_options = NAND_BBT_USE_FLASH;
714 
715 	chip->controller = &elbc_fcm_ctrl->controller;
716 	nand_set_controller_data(chip, priv);
717 
718 	return 0;
719 }
720 
721 static int fsl_elbc_attach_chip(struct nand_chip *chip)
722 {
723 	struct mtd_info *mtd = nand_to_mtd(chip);
724 	struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
725 	struct fsl_lbc_ctrl *ctrl = priv->ctrl;
726 	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
727 	unsigned int al;
728 	u32 br;
729 
730 	/*
731 	 * if ECC was not chosen in DT, decide whether to use HW or SW ECC from
732 	 * CS Base Register
733 	 */
734 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_INVALID) {
735 		/* If CS Base Register selects full hardware ECC then use it */
736 		if ((in_be32(&lbc->bank[priv->bank].br) & BR_DECC) ==
737 		    BR_DECC_CHK_GEN) {
738 			chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
739 		} else {
740 			/* otherwise fall back to default software ECC */
741 			chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
742 			chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
743 		}
744 	}
745 
746 	switch (chip->ecc.engine_type) {
747 	/* if HW ECC was chosen, setup ecc and oob layout */
748 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
749 		chip->ecc.read_page = fsl_elbc_read_page;
750 		chip->ecc.write_page = fsl_elbc_write_page;
751 		chip->ecc.write_subpage = fsl_elbc_write_subpage;
752 		mtd_set_ooblayout(mtd, &fsl_elbc_ooblayout_ops);
753 		chip->ecc.size = 512;
754 		chip->ecc.bytes = 3;
755 		chip->ecc.strength = 1;
756 		break;
757 
758 	/* if none or SW ECC was chosen, we do not need to set anything here */
759 	case NAND_ECC_ENGINE_TYPE_NONE:
760 	case NAND_ECC_ENGINE_TYPE_SOFT:
761 	case NAND_ECC_ENGINE_TYPE_ON_DIE:
762 		break;
763 
764 	default:
765 		return -EINVAL;
766 	}
767 
768 	/* enable/disable HW ECC checking and generating based on if HW ECC was chosen */
769 	br = in_be32(&lbc->bank[priv->bank].br) & ~BR_DECC;
770 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST)
771 		out_be32(&lbc->bank[priv->bank].br, br | BR_DECC_CHK_GEN);
772 	else
773 		out_be32(&lbc->bank[priv->bank].br, br | BR_DECC_OFF);
774 
775 	/* calculate FMR Address Length field */
776 	al = 0;
777 	if (chip->pagemask & 0xffff0000)
778 		al++;
779 	if (chip->pagemask & 0xff000000)
780 		al++;
781 
782 	priv->fmr |= al << FMR_AL_SHIFT;
783 
784 	dev_dbg(priv->dev, "fsl_elbc_init: nand->numchips = %d\n",
785 	        nanddev_ntargets(&chip->base));
786 	dev_dbg(priv->dev, "fsl_elbc_init: nand->chipsize = %lld\n",
787 	        nanddev_target_size(&chip->base));
788 	dev_dbg(priv->dev, "fsl_elbc_init: nand->pagemask = %8x\n",
789 	        chip->pagemask);
790 	dev_dbg(priv->dev, "fsl_elbc_init: nand->legacy.chip_delay = %d\n",
791 	        chip->legacy.chip_delay);
792 	dev_dbg(priv->dev, "fsl_elbc_init: nand->badblockpos = %d\n",
793 	        chip->badblockpos);
794 	dev_dbg(priv->dev, "fsl_elbc_init: nand->chip_shift = %d\n",
795 	        chip->chip_shift);
796 	dev_dbg(priv->dev, "fsl_elbc_init: nand->page_shift = %d\n",
797 	        chip->page_shift);
798 	dev_dbg(priv->dev, "fsl_elbc_init: nand->phys_erase_shift = %d\n",
799 	        chip->phys_erase_shift);
800 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.engine_type = %d\n",
801 		chip->ecc.engine_type);
802 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.steps = %d\n",
803 	        chip->ecc.steps);
804 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.bytes = %d\n",
805 	        chip->ecc.bytes);
806 	dev_dbg(priv->dev, "fsl_elbc_init: nand->ecc.total = %d\n",
807 	        chip->ecc.total);
808 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->ooblayout = %p\n",
809 		mtd->ooblayout);
810 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->flags = %08x\n", mtd->flags);
811 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->size = %lld\n", mtd->size);
812 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->erasesize = %d\n",
813 	        mtd->erasesize);
814 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->writesize = %d\n",
815 	        mtd->writesize);
816 	dev_dbg(priv->dev, "fsl_elbc_init: mtd->oobsize = %d\n",
817 	        mtd->oobsize);
818 
819 	/* adjust Option Register and ECC to match Flash page size */
820 	if (mtd->writesize == 512) {
821 		priv->page_size = 0;
822 		clrbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
823 	} else if (mtd->writesize == 2048) {
824 		priv->page_size = 1;
825 		setbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
826 	} else {
827 		dev_err(priv->dev,
828 		        "fsl_elbc_init: page size %d is not supported\n",
829 		        mtd->writesize);
830 		return -ENOTSUPP;
831 	}
832 
833 	return 0;
834 }
835 
836 static const struct nand_controller_ops fsl_elbc_controller_ops = {
837 	.attach_chip = fsl_elbc_attach_chip,
838 };
839 
840 static int fsl_elbc_chip_remove(struct fsl_elbc_mtd *priv)
841 {
842 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
843 	struct mtd_info *mtd = nand_to_mtd(&priv->chip);
844 
845 	kfree(mtd->name);
846 
847 	if (priv->vbase)
848 		iounmap(priv->vbase);
849 
850 	elbc_fcm_ctrl->chips[priv->bank] = NULL;
851 	kfree(priv);
852 	return 0;
853 }
854 
855 static DEFINE_MUTEX(fsl_elbc_nand_mutex);
856 
857 static int fsl_elbc_nand_probe(struct platform_device *pdev)
858 {
859 	struct fsl_lbc_regs __iomem *lbc;
860 	struct fsl_elbc_mtd *priv;
861 	struct resource res;
862 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl;
863 	static const char *part_probe_types[]
864 		= { "cmdlinepart", "RedBoot", "ofpart", NULL };
865 	int ret;
866 	int bank;
867 	struct device *dev;
868 	struct device_node *node = pdev->dev.of_node;
869 	struct mtd_info *mtd;
870 
871 	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
872 		return dev_err_probe(&pdev->dev, -EPROBE_DEFER, "lbc_ctrl_dev missing\n");
873 
874 	lbc = fsl_lbc_ctrl_dev->regs;
875 	dev = fsl_lbc_ctrl_dev->dev;
876 
877 	/* get, allocate and map the memory resource */
878 	ret = of_address_to_resource(node, 0, &res);
879 	if (ret) {
880 		dev_err(dev, "failed to get resource\n");
881 		return ret;
882 	}
883 
884 	/* find which chip select it is connected to */
885 	for (bank = 0; bank < MAX_BANKS; bank++)
886 		if ((in_be32(&lbc->bank[bank].br) & BR_V) &&
887 		    (in_be32(&lbc->bank[bank].br) & BR_MSEL) == BR_MS_FCM &&
888 		    (in_be32(&lbc->bank[bank].br) &
889 		     in_be32(&lbc->bank[bank].or) & BR_BA)
890 		     == fsl_lbc_addr(res.start))
891 			break;
892 
893 	if (bank >= MAX_BANKS) {
894 		dev_err(dev, "address did not match any chip selects\n");
895 		return -ENODEV;
896 	}
897 
898 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
899 	if (!priv)
900 		return -ENOMEM;
901 
902 	mutex_lock(&fsl_elbc_nand_mutex);
903 	if (!fsl_lbc_ctrl_dev->nand) {
904 		elbc_fcm_ctrl = kzalloc(sizeof(*elbc_fcm_ctrl), GFP_KERNEL);
905 		if (!elbc_fcm_ctrl) {
906 			mutex_unlock(&fsl_elbc_nand_mutex);
907 			ret = -ENOMEM;
908 			goto err;
909 		}
910 		elbc_fcm_ctrl->counter++;
911 
912 		nand_controller_init(&elbc_fcm_ctrl->controller);
913 		fsl_lbc_ctrl_dev->nand = elbc_fcm_ctrl;
914 	} else {
915 		elbc_fcm_ctrl = fsl_lbc_ctrl_dev->nand;
916 	}
917 	mutex_unlock(&fsl_elbc_nand_mutex);
918 
919 	elbc_fcm_ctrl->chips[bank] = priv;
920 	priv->bank = bank;
921 	priv->ctrl = fsl_lbc_ctrl_dev;
922 	priv->dev = &pdev->dev;
923 	dev_set_drvdata(priv->dev, priv);
924 
925 	priv->vbase = ioremap(res.start, resource_size(&res));
926 	if (!priv->vbase) {
927 		dev_err(dev, "failed to map chip region\n");
928 		ret = -ENOMEM;
929 		goto err;
930 	}
931 
932 	mtd = nand_to_mtd(&priv->chip);
933 	mtd->name = kasprintf(GFP_KERNEL, "%llx.flash", (u64)res.start);
934 	if (!nand_to_mtd(&priv->chip)->name) {
935 		ret = -ENOMEM;
936 		goto err;
937 	}
938 
939 	ret = fsl_elbc_chip_init(priv);
940 	if (ret)
941 		goto err;
942 
943 	priv->chip.controller->ops = &fsl_elbc_controller_ops;
944 	ret = nand_scan(&priv->chip, 1);
945 	if (ret)
946 		goto err;
947 
948 	/* First look for RedBoot table or partitions on the command
949 	 * line, these take precedence over device tree information */
950 	ret = mtd_device_parse_register(mtd, part_probe_types, NULL, NULL, 0);
951 	if (ret)
952 		goto cleanup_nand;
953 
954 	pr_info("eLBC NAND device at 0x%llx, bank %d\n",
955 		(unsigned long long)res.start, priv->bank);
956 
957 	return 0;
958 
959 cleanup_nand:
960 	nand_cleanup(&priv->chip);
961 err:
962 	fsl_elbc_chip_remove(priv);
963 
964 	return ret;
965 }
966 
967 static void fsl_elbc_nand_remove(struct platform_device *pdev)
968 {
969 	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = fsl_lbc_ctrl_dev->nand;
970 	struct fsl_elbc_mtd *priv = dev_get_drvdata(&pdev->dev);
971 	struct nand_chip *chip = &priv->chip;
972 	int ret;
973 
974 	ret = mtd_device_unregister(nand_to_mtd(chip));
975 	WARN_ON(ret);
976 	nand_cleanup(chip);
977 
978 	fsl_elbc_chip_remove(priv);
979 
980 	mutex_lock(&fsl_elbc_nand_mutex);
981 	elbc_fcm_ctrl->counter--;
982 	if (!elbc_fcm_ctrl->counter) {
983 		fsl_lbc_ctrl_dev->nand = NULL;
984 		kfree(elbc_fcm_ctrl);
985 	}
986 	mutex_unlock(&fsl_elbc_nand_mutex);
987 
988 }
989 
990 static const struct of_device_id fsl_elbc_nand_match[] = {
991 	{ .compatible = "fsl,elbc-fcm-nand", },
992 	{}
993 };
994 MODULE_DEVICE_TABLE(of, fsl_elbc_nand_match);
995 
996 static struct platform_driver fsl_elbc_nand_driver = {
997 	.driver = {
998 		.name = "fsl,elbc-fcm-nand",
999 		.of_match_table = fsl_elbc_nand_match,
1000 	},
1001 	.probe = fsl_elbc_nand_probe,
1002 	.remove_new = fsl_elbc_nand_remove,
1003 };
1004 
1005 module_platform_driver(fsl_elbc_nand_driver);
1006 
1007 MODULE_LICENSE("GPL");
1008 MODULE_AUTHOR("Freescale");
1009 MODULE_DESCRIPTION("Freescale Enhanced Local Bus Controller MTD NAND driver");
1010