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Merge tag 'powerpc-4.13-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[mirror_ubuntu-artful-kernel.git] / drivers / mtd / nand / atmel / pmecc.c
1 /*
2 * Copyright 2017 ATMEL
3 * Copyright 2017 Free Electrons
4 *
5 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
6 *
7 * Derived from the atmel_nand.c driver which contained the following
8 * copyrights:
9 *
10 * Copyright 2003 Rick Bronson
11 *
12 * Derived from drivers/mtd/nand/autcpu12.c
13 * Copyright 2001 Thomas Gleixner (gleixner@autronix.de)
14 *
15 * Derived from drivers/mtd/spia.c
16 * Copyright 2000 Steven J. Hill (sjhill@cotw.com)
17 *
18 * Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
19 * Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright 2007
20 *
21 * Derived from Das U-Boot source code
22 * (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
23 * Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
24 *
25 * Add Programmable Multibit ECC support for various AT91 SoC
26 * Copyright 2012 ATMEL, Hong Xu
27 *
28 * Add Nand Flash Controller support for SAMA5 SoC
29 * Copyright 2013 ATMEL, Josh Wu (josh.wu@atmel.com)
30 *
31 * This program is free software; you can redistribute it and/or modify
32 * it under the terms of the GNU General Public License version 2 as
33 * published by the Free Software Foundation.
34 *
35 * The PMECC is an hardware assisted BCH engine, which means part of the
36 * ECC algorithm is left to the software. The hardware/software repartition
37 * is explained in the "PMECC Controller Functional Description" chapter in
38 * Atmel datasheets, and some of the functions in this file are directly
39 * implementing the algorithms described in the "Software Implementation"
40 * sub-section.
41 *
42 * TODO: it seems that the software BCH implementation in lib/bch.c is already
43 * providing some of the logic we are implementing here. It would be smart
44 * to expose the needed lib/bch.c helpers/functions and re-use them here.
45 */
46
47 #include <linux/genalloc.h>
48 #include <linux/iopoll.h>
49 #include <linux/module.h>
50 #include <linux/mtd/nand.h>
51 #include <linux/of_irq.h>
52 #include <linux/of_platform.h>
53 #include <linux/platform_device.h>
54 #include <linux/slab.h>
55
56 #include "pmecc.h"
57
58 /* Galois field dimension */
59 #define PMECC_GF_DIMENSION_13 13
60 #define PMECC_GF_DIMENSION_14 14
61
62 /* Primitive Polynomial used by PMECC */
63 #define PMECC_GF_13_PRIMITIVE_POLY 0x201b
64 #define PMECC_GF_14_PRIMITIVE_POLY 0x4443
65
66 #define PMECC_LOOKUP_TABLE_SIZE_512 0x2000
67 #define PMECC_LOOKUP_TABLE_SIZE_1024 0x4000
68
69 /* Time out value for reading PMECC status register */
70 #define PMECC_MAX_TIMEOUT_MS 100
71
72 /* PMECC Register Definitions */
73 #define ATMEL_PMECC_CFG 0x0
74 #define PMECC_CFG_BCH_STRENGTH(x) (x)
75 #define PMECC_CFG_BCH_STRENGTH_MASK GENMASK(2, 0)
76 #define PMECC_CFG_SECTOR512 (0 << 4)
77 #define PMECC_CFG_SECTOR1024 (1 << 4)
78 #define PMECC_CFG_NSECTORS(x) ((fls(x) - 1) << 8)
79 #define PMECC_CFG_READ_OP (0 << 12)
80 #define PMECC_CFG_WRITE_OP (1 << 12)
81 #define PMECC_CFG_SPARE_ENABLE BIT(16)
82 #define PMECC_CFG_AUTO_ENABLE BIT(20)
83
84 #define ATMEL_PMECC_SAREA 0x4
85 #define ATMEL_PMECC_SADDR 0x8
86 #define ATMEL_PMECC_EADDR 0xc
87
88 #define ATMEL_PMECC_CLK 0x10
89 #define PMECC_CLK_133MHZ (2 << 0)
90
91 #define ATMEL_PMECC_CTRL 0x14
92 #define PMECC_CTRL_RST BIT(0)
93 #define PMECC_CTRL_DATA BIT(1)
94 #define PMECC_CTRL_USER BIT(2)
95 #define PMECC_CTRL_ENABLE BIT(4)
96 #define PMECC_CTRL_DISABLE BIT(5)
97
98 #define ATMEL_PMECC_SR 0x18
99 #define PMECC_SR_BUSY BIT(0)
100 #define PMECC_SR_ENABLE BIT(4)
101
102 #define ATMEL_PMECC_IER 0x1c
103 #define ATMEL_PMECC_IDR 0x20
104 #define ATMEL_PMECC_IMR 0x24
105 #define ATMEL_PMECC_ISR 0x28
106 #define PMECC_ERROR_INT BIT(0)
107
108 #define ATMEL_PMECC_ECC(sector, n) \
109 ((((sector) + 1) * 0x40) + (n))
110
111 #define ATMEL_PMECC_REM(sector, n) \
112 ((((sector) + 1) * 0x40) + ((n) * 4) + 0x200)
113
114 /* PMERRLOC Register Definitions */
115 #define ATMEL_PMERRLOC_ELCFG 0x0
116 #define PMERRLOC_ELCFG_SECTOR_512 (0 << 0)
117 #define PMERRLOC_ELCFG_SECTOR_1024 (1 << 0)
118 #define PMERRLOC_ELCFG_NUM_ERRORS(n) ((n) << 16)
119
120 #define ATMEL_PMERRLOC_ELPRIM 0x4
121 #define ATMEL_PMERRLOC_ELEN 0x8
122 #define ATMEL_PMERRLOC_ELDIS 0xc
123 #define PMERRLOC_DISABLE BIT(0)
124
125 #define ATMEL_PMERRLOC_ELSR 0x10
126 #define PMERRLOC_ELSR_BUSY BIT(0)
127
128 #define ATMEL_PMERRLOC_ELIER 0x14
129 #define ATMEL_PMERRLOC_ELIDR 0x18
130 #define ATMEL_PMERRLOC_ELIMR 0x1c
131 #define ATMEL_PMERRLOC_ELISR 0x20
132 #define PMERRLOC_ERR_NUM_MASK GENMASK(12, 8)
133 #define PMERRLOC_CALC_DONE BIT(0)
134
135 #define ATMEL_PMERRLOC_SIGMA(x) (((x) * 0x4) + 0x28)
136
137 #define ATMEL_PMERRLOC_EL(offs, x) (((x) * 0x4) + (offs))
138
139 struct atmel_pmecc_gf_tables {
140 u16 *alpha_to;
141 u16 *index_of;
142 };
143
144 struct atmel_pmecc_caps {
145 const int *strengths;
146 int nstrengths;
147 int el_offset;
148 bool correct_erased_chunks;
149 };
150
151 struct atmel_pmecc {
152 struct device *dev;
153 const struct atmel_pmecc_caps *caps;
154
155 struct {
156 void __iomem *base;
157 void __iomem *errloc;
158 } regs;
159
160 struct mutex lock;
161 };
162
163 struct atmel_pmecc_user_conf_cache {
164 u32 cfg;
165 u32 sarea;
166 u32 saddr;
167 u32 eaddr;
168 };
169
170 struct atmel_pmecc_user {
171 struct atmel_pmecc_user_conf_cache cache;
172 struct atmel_pmecc *pmecc;
173 const struct atmel_pmecc_gf_tables *gf_tables;
174 int eccbytes;
175 s16 *partial_syn;
176 s16 *si;
177 s16 *lmu;
178 s16 *smu;
179 s32 *mu;
180 s32 *dmu;
181 s32 *delta;
182 u32 isr;
183 };
184
185 static DEFINE_MUTEX(pmecc_gf_tables_lock);
186 static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_512;
187 static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_1024;
188
189 static inline int deg(unsigned int poly)
190 {
191 /* polynomial degree is the most-significant bit index */
192 return fls(poly) - 1;
193 }
194
195 static int atmel_pmecc_build_gf_tables(int mm, unsigned int poly,
196 struct atmel_pmecc_gf_tables *gf_tables)
197 {
198 unsigned int i, x = 1;
199 const unsigned int k = BIT(deg(poly));
200 unsigned int nn = BIT(mm) - 1;
201
202 /* primitive polynomial must be of degree m */
203 if (k != (1u << mm))
204 return -EINVAL;
205
206 for (i = 0; i < nn; i++) {
207 gf_tables->alpha_to[i] = x;
208 gf_tables->index_of[x] = i;
209 if (i && (x == 1))
210 /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */
211 return -EINVAL;
212 x <<= 1;
213 if (x & k)
214 x ^= poly;
215 }
216 gf_tables->alpha_to[nn] = 1;
217 gf_tables->index_of[0] = 0;
218
219 return 0;
220 }
221
222 static const struct atmel_pmecc_gf_tables *
223 atmel_pmecc_create_gf_tables(const struct atmel_pmecc_user_req *req)
224 {
225 struct atmel_pmecc_gf_tables *gf_tables;
226 unsigned int poly, degree, table_size;
227 int ret;
228
229 if (req->ecc.sectorsize == 512) {
230 degree = PMECC_GF_DIMENSION_13;
231 poly = PMECC_GF_13_PRIMITIVE_POLY;
232 table_size = PMECC_LOOKUP_TABLE_SIZE_512;
233 } else {
234 degree = PMECC_GF_DIMENSION_14;
235 poly = PMECC_GF_14_PRIMITIVE_POLY;
236 table_size = PMECC_LOOKUP_TABLE_SIZE_1024;
237 }
238
239 gf_tables = kzalloc(sizeof(*gf_tables) +
240 (2 * table_size * sizeof(u16)),
241 GFP_KERNEL);
242 if (!gf_tables)
243 return ERR_PTR(-ENOMEM);
244
245 gf_tables->alpha_to = (void *)(gf_tables + 1);
246 gf_tables->index_of = gf_tables->alpha_to + table_size;
247
248 ret = atmel_pmecc_build_gf_tables(degree, poly, gf_tables);
249 if (ret) {
250 kfree(gf_tables);
251 return ERR_PTR(ret);
252 }
253
254 return gf_tables;
255 }
256
257 static const struct atmel_pmecc_gf_tables *
258 atmel_pmecc_get_gf_tables(const struct atmel_pmecc_user_req *req)
259 {
260 const struct atmel_pmecc_gf_tables **gf_tables, *ret;
261
262 mutex_lock(&pmecc_gf_tables_lock);
263 if (req->ecc.sectorsize == 512)
264 gf_tables = &pmecc_gf_tables_512;
265 else
266 gf_tables = &pmecc_gf_tables_1024;
267
268 ret = *gf_tables;
269
270 if (!ret) {
271 ret = atmel_pmecc_create_gf_tables(req);
272 if (!IS_ERR(ret))
273 *gf_tables = ret;
274 }
275 mutex_unlock(&pmecc_gf_tables_lock);
276
277 return ret;
278 }
279
280 static int atmel_pmecc_prepare_user_req(struct atmel_pmecc *pmecc,
281 struct atmel_pmecc_user_req *req)
282 {
283 int i, max_eccbytes, eccbytes = 0, eccstrength = 0;
284
285 if (req->pagesize <= 0 || req->oobsize <= 0 || req->ecc.bytes <= 0)
286 return -EINVAL;
287
288 if (req->ecc.ooboffset >= 0 &&
289 req->ecc.ooboffset + req->ecc.bytes > req->oobsize)
290 return -EINVAL;
291
292 if (req->ecc.sectorsize == ATMEL_PMECC_SECTOR_SIZE_AUTO) {
293 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH)
294 return -EINVAL;
295
296 if (req->pagesize > 512)
297 req->ecc.sectorsize = 1024;
298 else
299 req->ecc.sectorsize = 512;
300 }
301
302 if (req->ecc.sectorsize != 512 && req->ecc.sectorsize != 1024)
303 return -EINVAL;
304
305 if (req->pagesize % req->ecc.sectorsize)
306 return -EINVAL;
307
308 req->ecc.nsectors = req->pagesize / req->ecc.sectorsize;
309
310 max_eccbytes = req->ecc.bytes;
311
312 for (i = 0; i < pmecc->caps->nstrengths; i++) {
313 int nbytes, strength = pmecc->caps->strengths[i];
314
315 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH &&
316 strength < req->ecc.strength)
317 continue;
318
319 nbytes = DIV_ROUND_UP(strength * fls(8 * req->ecc.sectorsize),
320 8);
321 nbytes *= req->ecc.nsectors;
322
323 if (nbytes > max_eccbytes)
324 break;
325
326 eccstrength = strength;
327 eccbytes = nbytes;
328
329 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH)
330 break;
331 }
332
333 if (!eccstrength)
334 return -EINVAL;
335
336 req->ecc.bytes = eccbytes;
337 req->ecc.strength = eccstrength;
338
339 if (req->ecc.ooboffset < 0)
340 req->ecc.ooboffset = req->oobsize - eccbytes;
341
342 return 0;
343 }
344
345 struct atmel_pmecc_user *
346 atmel_pmecc_create_user(struct atmel_pmecc *pmecc,
347 struct atmel_pmecc_user_req *req)
348 {
349 struct atmel_pmecc_user *user;
350 const struct atmel_pmecc_gf_tables *gf_tables;
351 int strength, size, ret;
352
353 ret = atmel_pmecc_prepare_user_req(pmecc, req);
354 if (ret)
355 return ERR_PTR(ret);
356
357 size = sizeof(*user);
358 size = ALIGN(size, sizeof(u16));
359 /* Reserve space for partial_syn, si and smu */
360 size += ((2 * req->ecc.strength) + 1) * sizeof(u16) *
361 (2 + req->ecc.strength + 2);
362 /* Reserve space for lmu. */
363 size += (req->ecc.strength + 1) * sizeof(u16);
364 /* Reserve space for mu, dmu and delta. */
365 size = ALIGN(size, sizeof(s32));
366 size += (req->ecc.strength + 1) * sizeof(s32);
367
368 user = kzalloc(size, GFP_KERNEL);
369 if (!user)
370 return ERR_PTR(-ENOMEM);
371
372 user->pmecc = pmecc;
373
374 user->partial_syn = (s16 *)PTR_ALIGN(user + 1, sizeof(u16));
375 user->si = user->partial_syn + ((2 * req->ecc.strength) + 1);
376 user->lmu = user->si + ((2 * req->ecc.strength) + 1);
377 user->smu = user->lmu + (req->ecc.strength + 1);
378 user->mu = (s32 *)PTR_ALIGN(user->smu +
379 (((2 * req->ecc.strength) + 1) *
380 (req->ecc.strength + 2)),
381 sizeof(s32));
382 user->dmu = user->mu + req->ecc.strength + 1;
383 user->delta = user->dmu + req->ecc.strength + 1;
384
385 gf_tables = atmel_pmecc_get_gf_tables(req);
386 if (IS_ERR(gf_tables)) {
387 kfree(user);
388 return ERR_CAST(gf_tables);
389 }
390
391 user->gf_tables = gf_tables;
392
393 user->eccbytes = req->ecc.bytes / req->ecc.nsectors;
394
395 for (strength = 0; strength < pmecc->caps->nstrengths; strength++) {
396 if (pmecc->caps->strengths[strength] == req->ecc.strength)
397 break;
398 }
399
400 user->cache.cfg = PMECC_CFG_BCH_STRENGTH(strength) |
401 PMECC_CFG_NSECTORS(req->ecc.nsectors);
402
403 if (req->ecc.sectorsize == 1024)
404 user->cache.cfg |= PMECC_CFG_SECTOR1024;
405
406 user->cache.sarea = req->oobsize - 1;
407 user->cache.saddr = req->ecc.ooboffset;
408 user->cache.eaddr = req->ecc.ooboffset + req->ecc.bytes - 1;
409
410 return user;
411 }
412 EXPORT_SYMBOL_GPL(atmel_pmecc_create_user);
413
414 void atmel_pmecc_destroy_user(struct atmel_pmecc_user *user)
415 {
416 kfree(user);
417 }
418 EXPORT_SYMBOL_GPL(atmel_pmecc_destroy_user);
419
420 static int get_strength(struct atmel_pmecc_user *user)
421 {
422 const int *strengths = user->pmecc->caps->strengths;
423
424 return strengths[user->cache.cfg & PMECC_CFG_BCH_STRENGTH_MASK];
425 }
426
427 static int get_sectorsize(struct atmel_pmecc_user *user)
428 {
429 return user->cache.cfg & PMECC_LOOKUP_TABLE_SIZE_1024 ? 1024 : 512;
430 }
431
432 static void atmel_pmecc_gen_syndrome(struct atmel_pmecc_user *user, int sector)
433 {
434 int strength = get_strength(user);
435 u32 value;
436 int i;
437
438 /* Fill odd syndromes */
439 for (i = 0; i < strength; i++) {
440 value = readl_relaxed(user->pmecc->regs.base +
441 ATMEL_PMECC_REM(sector, i / 2));
442 if (i & 1)
443 value >>= 16;
444
445 user->partial_syn[(2 * i) + 1] = value;
446 }
447 }
448
449 static void atmel_pmecc_substitute(struct atmel_pmecc_user *user)
450 {
451 int degree = get_sectorsize(user) == 512 ? 13 : 14;
452 int cw_len = BIT(degree) - 1;
453 int strength = get_strength(user);
454 s16 *alpha_to = user->gf_tables->alpha_to;
455 s16 *index_of = user->gf_tables->index_of;
456 s16 *partial_syn = user->partial_syn;
457 s16 *si;
458 int i, j;
459
460 /*
461 * si[] is a table that holds the current syndrome value,
462 * an element of that table belongs to the field
463 */
464 si = user->si;
465
466 memset(&si[1], 0, sizeof(s16) * ((2 * strength) - 1));
467
468 /* Computation 2t syndromes based on S(x) */
469 /* Odd syndromes */
470 for (i = 1; i < 2 * strength; i += 2) {
471 for (j = 0; j < degree; j++) {
472 if (partial_syn[i] & BIT(j))
473 si[i] = alpha_to[i * j] ^ si[i];
474 }
475 }
476 /* Even syndrome = (Odd syndrome) ** 2 */
477 for (i = 2, j = 1; j <= strength; i = ++j << 1) {
478 if (si[j] == 0) {
479 si[i] = 0;
480 } else {
481 s16 tmp;
482
483 tmp = index_of[si[j]];
484 tmp = (tmp * 2) % cw_len;
485 si[i] = alpha_to[tmp];
486 }
487 }
488 }
489
490 static void atmel_pmecc_get_sigma(struct atmel_pmecc_user *user)
491 {
492 s16 *lmu = user->lmu;
493 s16 *si = user->si;
494 s32 *mu = user->mu;
495 s32 *dmu = user->dmu;
496 s32 *delta = user->delta;
497 int degree = get_sectorsize(user) == 512 ? 13 : 14;
498 int cw_len = BIT(degree) - 1;
499 int strength = get_strength(user);
500 int num = 2 * strength + 1;
501 s16 *index_of = user->gf_tables->index_of;
502 s16 *alpha_to = user->gf_tables->alpha_to;
503 int i, j, k;
504 u32 dmu_0_count, tmp;
505 s16 *smu = user->smu;
506
507 /* index of largest delta */
508 int ro;
509 int largest;
510 int diff;
511
512 dmu_0_count = 0;
513
514 /* First Row */
515
516 /* Mu */
517 mu[0] = -1;
518
519 memset(smu, 0, sizeof(s16) * num);
520 smu[0] = 1;
521
522 /* discrepancy set to 1 */
523 dmu[0] = 1;
524 /* polynom order set to 0 */
525 lmu[0] = 0;
526 delta[0] = (mu[0] * 2 - lmu[0]) >> 1;
527
528 /* Second Row */
529
530 /* Mu */
531 mu[1] = 0;
532 /* Sigma(x) set to 1 */
533 memset(&smu[num], 0, sizeof(s16) * num);
534 smu[num] = 1;
535
536 /* discrepancy set to S1 */
537 dmu[1] = si[1];
538
539 /* polynom order set to 0 */
540 lmu[1] = 0;
541
542 delta[1] = (mu[1] * 2 - lmu[1]) >> 1;
543
544 /* Init the Sigma(x) last row */
545 memset(&smu[(strength + 1) * num], 0, sizeof(s16) * num);
546
547 for (i = 1; i <= strength; i++) {
548 mu[i + 1] = i << 1;
549 /* Begin Computing Sigma (Mu+1) and L(mu) */
550 /* check if discrepancy is set to 0 */
551 if (dmu[i] == 0) {
552 dmu_0_count++;
553
554 tmp = ((strength - (lmu[i] >> 1) - 1) / 2);
555 if ((strength - (lmu[i] >> 1) - 1) & 0x1)
556 tmp += 2;
557 else
558 tmp += 1;
559
560 if (dmu_0_count == tmp) {
561 for (j = 0; j <= (lmu[i] >> 1) + 1; j++)
562 smu[(strength + 1) * num + j] =
563 smu[i * num + j];
564
565 lmu[strength + 1] = lmu[i];
566 return;
567 }
568
569 /* copy polynom */
570 for (j = 0; j <= lmu[i] >> 1; j++)
571 smu[(i + 1) * num + j] = smu[i * num + j];
572
573 /* copy previous polynom order to the next */
574 lmu[i + 1] = lmu[i];
575 } else {
576 ro = 0;
577 largest = -1;
578 /* find largest delta with dmu != 0 */
579 for (j = 0; j < i; j++) {
580 if ((dmu[j]) && (delta[j] > largest)) {
581 largest = delta[j];
582 ro = j;
583 }
584 }
585
586 /* compute difference */
587 diff = (mu[i] - mu[ro]);
588
589 /* Compute degree of the new smu polynomial */
590 if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff))
591 lmu[i + 1] = lmu[i];
592 else
593 lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2;
594
595 /* Init smu[i+1] with 0 */
596 for (k = 0; k < num; k++)
597 smu[(i + 1) * num + k] = 0;
598
599 /* Compute smu[i+1] */
600 for (k = 0; k <= lmu[ro] >> 1; k++) {
601 s16 a, b, c;
602
603 if (!(smu[ro * num + k] && dmu[i]))
604 continue;
605
606 a = index_of[dmu[i]];
607 b = index_of[dmu[ro]];
608 c = index_of[smu[ro * num + k]];
609 tmp = a + (cw_len - b) + c;
610 a = alpha_to[tmp % cw_len];
611 smu[(i + 1) * num + (k + diff)] = a;
612 }
613
614 for (k = 0; k <= lmu[i] >> 1; k++)
615 smu[(i + 1) * num + k] ^= smu[i * num + k];
616 }
617
618 /* End Computing Sigma (Mu+1) and L(mu) */
619 /* In either case compute delta */
620 delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1;
621
622 /* Do not compute discrepancy for the last iteration */
623 if (i >= strength)
624 continue;
625
626 for (k = 0; k <= (lmu[i + 1] >> 1); k++) {
627 tmp = 2 * (i - 1);
628 if (k == 0) {
629 dmu[i + 1] = si[tmp + 3];
630 } else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) {
631 s16 a, b, c;
632
633 a = index_of[smu[(i + 1) * num + k]];
634 b = si[2 * (i - 1) + 3 - k];
635 c = index_of[b];
636 tmp = a + c;
637 tmp %= cw_len;
638 dmu[i + 1] = alpha_to[tmp] ^ dmu[i + 1];
639 }
640 }
641 }
642 }
643
644 static int atmel_pmecc_err_location(struct atmel_pmecc_user *user)
645 {
646 int sector_size = get_sectorsize(user);
647 int degree = sector_size == 512 ? 13 : 14;
648 struct atmel_pmecc *pmecc = user->pmecc;
649 int strength = get_strength(user);
650 int ret, roots_nbr, i, err_nbr = 0;
651 int num = (2 * strength) + 1;
652 s16 *smu = user->smu;
653 u32 val;
654
655 writel(PMERRLOC_DISABLE, pmecc->regs.errloc + ATMEL_PMERRLOC_ELDIS);
656
657 for (i = 0; i <= user->lmu[strength + 1] >> 1; i++) {
658 writel_relaxed(smu[(strength + 1) * num + i],
659 pmecc->regs.errloc + ATMEL_PMERRLOC_SIGMA(i));
660 err_nbr++;
661 }
662
663 val = (err_nbr - 1) << 16;
664 if (sector_size == 1024)
665 val |= 1;
666
667 writel(val, pmecc->regs.errloc + ATMEL_PMERRLOC_ELCFG);
668 writel((sector_size * 8) + (degree * strength),
669 pmecc->regs.errloc + ATMEL_PMERRLOC_ELEN);
670
671 ret = readl_relaxed_poll_timeout(pmecc->regs.errloc +
672 ATMEL_PMERRLOC_ELISR,
673 val, val & PMERRLOC_CALC_DONE, 0,
674 PMECC_MAX_TIMEOUT_MS * 1000);
675 if (ret) {
676 dev_err(pmecc->dev,
677 "PMECC: Timeout to calculate error location.\n");
678 return ret;
679 }
680
681 roots_nbr = (val & PMERRLOC_ERR_NUM_MASK) >> 8;
682 /* Number of roots == degree of smu hence <= cap */
683 if (roots_nbr == user->lmu[strength + 1] >> 1)
684 return err_nbr - 1;
685
686 /*
687 * Number of roots does not match the degree of smu
688 * unable to correct error.
689 */
690 return -EBADMSG;
691 }
692
693 int atmel_pmecc_correct_sector(struct atmel_pmecc_user *user, int sector,
694 void *data, void *ecc)
695 {
696 struct atmel_pmecc *pmecc = user->pmecc;
697 int sectorsize = get_sectorsize(user);
698 int eccbytes = user->eccbytes;
699 int i, nerrors;
700
701 if (!(user->isr & BIT(sector)))
702 return 0;
703
704 atmel_pmecc_gen_syndrome(user, sector);
705 atmel_pmecc_substitute(user);
706 atmel_pmecc_get_sigma(user);
707
708 nerrors = atmel_pmecc_err_location(user);
709 if (nerrors < 0)
710 return nerrors;
711
712 for (i = 0; i < nerrors; i++) {
713 const char *area;
714 int byte, bit;
715 u32 errpos;
716 u8 *ptr;
717
718 errpos = readl_relaxed(pmecc->regs.errloc +
719 ATMEL_PMERRLOC_EL(pmecc->caps->el_offset, i));
720 errpos--;
721
722 byte = errpos / 8;
723 bit = errpos % 8;
724
725 if (byte < sectorsize) {
726 ptr = data + byte;
727 area = "data";
728 } else if (byte < sectorsize + eccbytes) {
729 ptr = ecc + byte - sectorsize;
730 area = "ECC";
731 } else {
732 dev_dbg(pmecc->dev,
733 "Invalid errpos value (%d, max is %d)\n",
734 errpos, (sectorsize + eccbytes) * 8);
735 return -EINVAL;
736 }
737
738 dev_dbg(pmecc->dev,
739 "Bit flip in %s area, byte %d: 0x%02x -> 0x%02x\n",
740 area, byte, *ptr, (unsigned int)(*ptr ^ BIT(bit)));
741
742 *ptr ^= BIT(bit);
743 }
744
745 return nerrors;
746 }
747 EXPORT_SYMBOL_GPL(atmel_pmecc_correct_sector);
748
749 bool atmel_pmecc_correct_erased_chunks(struct atmel_pmecc_user *user)
750 {
751 return user->pmecc->caps->correct_erased_chunks;
752 }
753 EXPORT_SYMBOL_GPL(atmel_pmecc_correct_erased_chunks);
754
755 void atmel_pmecc_get_generated_eccbytes(struct atmel_pmecc_user *user,
756 int sector, void *ecc)
757 {
758 struct atmel_pmecc *pmecc = user->pmecc;
759 u8 *ptr = ecc;
760 int i;
761
762 for (i = 0; i < user->eccbytes; i++)
763 ptr[i] = readb_relaxed(pmecc->regs.base +
764 ATMEL_PMECC_ECC(sector, i));
765 }
766 EXPORT_SYMBOL_GPL(atmel_pmecc_get_generated_eccbytes);
767
768 int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op)
769 {
770 struct atmel_pmecc *pmecc = user->pmecc;
771 u32 cfg;
772
773 if (op != NAND_ECC_READ && op != NAND_ECC_WRITE) {
774 dev_err(pmecc->dev, "Bad ECC operation!");
775 return -EINVAL;
776 }
777
778 mutex_lock(&user->pmecc->lock);
779
780 cfg = user->cache.cfg;
781 if (op == NAND_ECC_WRITE)
782 cfg |= PMECC_CFG_WRITE_OP;
783 else
784 cfg |= PMECC_CFG_AUTO_ENABLE;
785
786 writel(cfg, pmecc->regs.base + ATMEL_PMECC_CFG);
787 writel(user->cache.sarea, pmecc->regs.base + ATMEL_PMECC_SAREA);
788 writel(user->cache.saddr, pmecc->regs.base + ATMEL_PMECC_SADDR);
789 writel(user->cache.eaddr, pmecc->regs.base + ATMEL_PMECC_EADDR);
790
791 writel(PMECC_CTRL_ENABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
792 writel(PMECC_CTRL_DATA, pmecc->regs.base + ATMEL_PMECC_CTRL);
793
794 return 0;
795 }
796 EXPORT_SYMBOL_GPL(atmel_pmecc_enable);
797
798 void atmel_pmecc_disable(struct atmel_pmecc_user *user)
799 {
800 struct atmel_pmecc *pmecc = user->pmecc;
801
802 writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
803 writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
804 mutex_unlock(&user->pmecc->lock);
805 }
806 EXPORT_SYMBOL_GPL(atmel_pmecc_disable);
807
808 int atmel_pmecc_wait_rdy(struct atmel_pmecc_user *user)
809 {
810 struct atmel_pmecc *pmecc = user->pmecc;
811 u32 status;
812 int ret;
813
814 ret = readl_relaxed_poll_timeout(pmecc->regs.base +
815 ATMEL_PMECC_SR,
816 status, !(status & PMECC_SR_BUSY), 0,
817 PMECC_MAX_TIMEOUT_MS * 1000);
818 if (ret) {
819 dev_err(pmecc->dev,
820 "Timeout while waiting for PMECC ready.\n");
821 return ret;
822 }
823
824 user->isr = readl_relaxed(pmecc->regs.base + ATMEL_PMECC_ISR);
825
826 return 0;
827 }
828 EXPORT_SYMBOL_GPL(atmel_pmecc_wait_rdy);
829
830 static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev,
831 const struct atmel_pmecc_caps *caps,
832 int pmecc_res_idx, int errloc_res_idx)
833 {
834 struct device *dev = &pdev->dev;
835 struct atmel_pmecc *pmecc;
836 struct resource *res;
837
838 pmecc = devm_kzalloc(dev, sizeof(*pmecc), GFP_KERNEL);
839 if (!pmecc)
840 return ERR_PTR(-ENOMEM);
841
842 pmecc->caps = caps;
843 pmecc->dev = dev;
844 mutex_init(&pmecc->lock);
845
846 res = platform_get_resource(pdev, IORESOURCE_MEM, pmecc_res_idx);
847 pmecc->regs.base = devm_ioremap_resource(dev, res);
848 if (IS_ERR(pmecc->regs.base))
849 return ERR_CAST(pmecc->regs.base);
850
851 res = platform_get_resource(pdev, IORESOURCE_MEM, errloc_res_idx);
852 pmecc->regs.errloc = devm_ioremap_resource(dev, res);
853 if (IS_ERR(pmecc->regs.errloc))
854 return ERR_CAST(pmecc->regs.errloc);
855
856 /* Disable all interrupts before registering the PMECC handler. */
857 writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR);
858
859 /* Reset the ECC engine */
860 writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
861 writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
862
863 return pmecc;
864 }
865
866 static void devm_atmel_pmecc_put(struct device *dev, void *res)
867 {
868 struct atmel_pmecc **pmecc = res;
869
870 put_device((*pmecc)->dev);
871 }
872
873 static struct atmel_pmecc *atmel_pmecc_get_by_node(struct device *userdev,
874 struct device_node *np)
875 {
876 struct platform_device *pdev;
877 struct atmel_pmecc *pmecc, **ptr;
878
879 pdev = of_find_device_by_node(np);
880 if (!pdev || !platform_get_drvdata(pdev))
881 return ERR_PTR(-EPROBE_DEFER);
882
883 ptr = devres_alloc(devm_atmel_pmecc_put, sizeof(*ptr), GFP_KERNEL);
884 if (!ptr)
885 return ERR_PTR(-ENOMEM);
886
887 get_device(&pdev->dev);
888 pmecc = platform_get_drvdata(pdev);
889
890 *ptr = pmecc;
891
892 devres_add(userdev, ptr);
893
894 return pmecc;
895 }
896
897 static const int atmel_pmecc_strengths[] = { 2, 4, 8, 12, 24, 32 };
898
899 static struct atmel_pmecc_caps at91sam9g45_caps = {
900 .strengths = atmel_pmecc_strengths,
901 .nstrengths = 5,
902 .el_offset = 0x8c,
903 };
904
905 static struct atmel_pmecc_caps sama5d4_caps = {
906 .strengths = atmel_pmecc_strengths,
907 .nstrengths = 5,
908 .el_offset = 0x8c,
909 .correct_erased_chunks = true,
910 };
911
912 static struct atmel_pmecc_caps sama5d2_caps = {
913 .strengths = atmel_pmecc_strengths,
914 .nstrengths = 6,
915 .el_offset = 0xac,
916 .correct_erased_chunks = true,
917 };
918
919 static const struct of_device_id atmel_pmecc_legacy_match[] = {
920 { .compatible = "atmel,sama5d4-nand", &sama5d4_caps },
921 { .compatible = "atmel,sama5d2-nand", &sama5d2_caps },
922 { /* sentinel */ }
923 };
924
925 struct atmel_pmecc *devm_atmel_pmecc_get(struct device *userdev)
926 {
927 struct atmel_pmecc *pmecc;
928 struct device_node *np;
929
930 if (!userdev)
931 return ERR_PTR(-EINVAL);
932
933 if (!userdev->of_node)
934 return NULL;
935
936 np = of_parse_phandle(userdev->of_node, "ecc-engine", 0);
937 if (np) {
938 pmecc = atmel_pmecc_get_by_node(userdev, np);
939 of_node_put(np);
940 } else {
941 /*
942 * Support old DT bindings: in this case the PMECC iomem
943 * resources are directly defined in the user pdev at position
944 * 1 and 2. Extract all relevant information from there.
945 */
946 struct platform_device *pdev = to_platform_device(userdev);
947 const struct atmel_pmecc_caps *caps;
948 const struct of_device_id *match;
949
950 /* No PMECC engine available. */
951 if (!of_property_read_bool(userdev->of_node,
952 "atmel,has-pmecc"))
953 return NULL;
954
955 caps = &at91sam9g45_caps;
956
957 /* Find the caps associated to the NAND dev node. */
958 match = of_match_node(atmel_pmecc_legacy_match,
959 userdev->of_node);
960 if (match && match->data)
961 caps = match->data;
962
963 pmecc = atmel_pmecc_create(pdev, caps, 1, 2);
964 }
965
966 return pmecc;
967 }
968 EXPORT_SYMBOL(devm_atmel_pmecc_get);
969
970 static const struct of_device_id atmel_pmecc_match[] = {
971 { .compatible = "atmel,at91sam9g45-pmecc", &at91sam9g45_caps },
972 { .compatible = "atmel,sama5d4-pmecc", &sama5d4_caps },
973 { .compatible = "atmel,sama5d2-pmecc", &sama5d2_caps },
974 { /* sentinel */ }
975 };
976 MODULE_DEVICE_TABLE(of, atmel_pmecc_match);
977
978 static int atmel_pmecc_probe(struct platform_device *pdev)
979 {
980 struct device *dev = &pdev->dev;
981 const struct atmel_pmecc_caps *caps;
982 struct atmel_pmecc *pmecc;
983
984 caps = of_device_get_match_data(&pdev->dev);
985 if (!caps) {
986 dev_err(dev, "Invalid caps\n");
987 return -EINVAL;
988 }
989
990 pmecc = atmel_pmecc_create(pdev, caps, 0, 1);
991 if (IS_ERR(pmecc))
992 return PTR_ERR(pmecc);
993
994 platform_set_drvdata(pdev, pmecc);
995
996 return 0;
997 }
998
999 static struct platform_driver atmel_pmecc_driver = {
1000 .driver = {
1001 .name = "atmel-pmecc",
1002 .of_match_table = of_match_ptr(atmel_pmecc_match),
1003 },
1004 .probe = atmel_pmecc_probe,
1005 };
1006 module_platform_driver(atmel_pmecc_driver);
1007
1008 MODULE_LICENSE("GPL");
1009 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
1010 MODULE_DESCRIPTION("PMECC engine driver");
1011 MODULE_ALIAS("platform:atmel_pmecc");
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