1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright 2017 ATMEL
4 * Copyright 2017 Free Electrons
5 *
6 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
7 *
8 * Derived from the atmel_nand.c driver which contained the following
9 * copyrights:
10 *
11 * Copyright 2003 Rick Bronson
12 *
13 * Derived from drivers/mtd/nand/autcpu12.c (removed in v3.8)
14 * Copyright 2001 Thomas Gleixner (gleixner@autronix.de)
15 *
16 * Derived from drivers/mtd/spia.c (removed in v3.8)
17 * Copyright 2000 Steven J. Hill (sjhill@cotw.com)
18 *
19 * Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
20 * Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright 2007
21 *
22 * Derived from Das U-Boot source code
23 * (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
24 * Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
25 *
26 * Add Programmable Multibit ECC support for various AT91 SoC
27 * Copyright 2012 ATMEL, Hong Xu
28 *
29 * Add Nand Flash Controller support for SAMA5 SoC
30 * Copyright 2013 ATMEL, Josh Wu (josh.wu@atmel.com)
31 *
32 * The PMECC is an hardware assisted BCH engine, which means part of the
33 * ECC algorithm is left to the software. The hardware/software repartition
34 * is explained in the "PMECC Controller Functional Description" chapter in
35 * Atmel datasheets, and some of the functions in this file are directly
36 * implementing the algorithms described in the "Software Implementation"
37 * sub-section.
38 *
39 * TODO: it seems that the software BCH implementation in lib/bch.c is already
40 * providing some of the logic we are implementing here. It would be smart
41 * to expose the needed lib/bch.c helpers/functions and re-use them here.
42 */
43
44 #include <linux/genalloc.h>
45 #include <linux/iopoll.h>
46 #include <linux/module.h>
47 #include <linux/mtd/rawnand.h>
48 #include <linux/of_irq.h>
49 #include <linux/of_platform.h>
50 #include <linux/platform_device.h>
51 #include <linux/slab.h>
52
53 #include "pmecc.h"
54
55 /* Galois field dimension */
56 #define PMECC_GF_DIMENSION_13 13
57 #define PMECC_GF_DIMENSION_14 14
58
59 /* Primitive Polynomial used by PMECC */
60 #define PMECC_GF_13_PRIMITIVE_POLY 0x201b
61 #define PMECC_GF_14_PRIMITIVE_POLY 0x4443
62
63 #define PMECC_LOOKUP_TABLE_SIZE_512 0x2000
64 #define PMECC_LOOKUP_TABLE_SIZE_1024 0x4000
65
66 /* Time out value for reading PMECC status register */
67 #define PMECC_MAX_TIMEOUT_MS 100
68
69 /* PMECC Register Definitions */
70 #define ATMEL_PMECC_CFG 0x0
71 #define PMECC_CFG_BCH_STRENGTH(x) (x)
72 #define PMECC_CFG_BCH_STRENGTH_MASK GENMASK(2, 0)
73 #define PMECC_CFG_SECTOR512 (0 << 4)
74 #define PMECC_CFG_SECTOR1024 (1 << 4)
75 #define PMECC_CFG_NSECTORS(x) ((fls(x) - 1) << 8)
76 #define PMECC_CFG_READ_OP (0 << 12)
77 #define PMECC_CFG_WRITE_OP (1 << 12)
78 #define PMECC_CFG_SPARE_ENABLE BIT(16)
79 #define PMECC_CFG_AUTO_ENABLE BIT(20)
80
81 #define ATMEL_PMECC_SAREA 0x4
82 #define ATMEL_PMECC_SADDR 0x8
83 #define ATMEL_PMECC_EADDR 0xc
84
85 #define ATMEL_PMECC_CLK 0x10
86 #define PMECC_CLK_133MHZ (2 << 0)
87
88 #define ATMEL_PMECC_CTRL 0x14
89 #define PMECC_CTRL_RST BIT(0)
90 #define PMECC_CTRL_DATA BIT(1)
91 #define PMECC_CTRL_USER BIT(2)
92 #define PMECC_CTRL_ENABLE BIT(4)
93 #define PMECC_CTRL_DISABLE BIT(5)
94
95 #define ATMEL_PMECC_SR 0x18
96 #define PMECC_SR_BUSY BIT(0)
97 #define PMECC_SR_ENABLE BIT(4)
98
99 #define ATMEL_PMECC_IER 0x1c
100 #define ATMEL_PMECC_IDR 0x20
101 #define ATMEL_PMECC_IMR 0x24
102 #define ATMEL_PMECC_ISR 0x28
103 #define PMECC_ERROR_INT BIT(0)
104
105 #define ATMEL_PMECC_ECC(sector, n) \
106 ((((sector) + 1) * 0x40) + (n))
107
108 #define ATMEL_PMECC_REM(sector, n) \
109 ((((sector) + 1) * 0x40) + ((n) * 4) + 0x200)
110
111 /* PMERRLOC Register Definitions */
112 #define ATMEL_PMERRLOC_ELCFG 0x0
113 #define PMERRLOC_ELCFG_SECTOR_512 (0 << 0)
114 #define PMERRLOC_ELCFG_SECTOR_1024 (1 << 0)
115 #define PMERRLOC_ELCFG_NUM_ERRORS(n) ((n) << 16)
116
117 #define ATMEL_PMERRLOC_ELPRIM 0x4
118 #define ATMEL_PMERRLOC_ELEN 0x8
119 #define ATMEL_PMERRLOC_ELDIS 0xc
120 #define PMERRLOC_DISABLE BIT(0)
121
122 #define ATMEL_PMERRLOC_ELSR 0x10
123 #define PMERRLOC_ELSR_BUSY BIT(0)
124
125 #define ATMEL_PMERRLOC_ELIER 0x14
126 #define ATMEL_PMERRLOC_ELIDR 0x18
127 #define ATMEL_PMERRLOC_ELIMR 0x1c
128 #define ATMEL_PMERRLOC_ELISR 0x20
129 #define PMERRLOC_ERR_NUM_MASK GENMASK(12, 8)
130 #define PMERRLOC_CALC_DONE BIT(0)
131
132 #define ATMEL_PMERRLOC_SIGMA(x) (((x) * 0x4) + 0x28)
133
134 #define ATMEL_PMERRLOC_EL(offs, x) (((x) * 0x4) + (offs))
135
136 struct atmel_pmecc_gf_tables {
137 u16 *alpha_to;
138 u16 *index_of;
139 };
140
141 struct atmel_pmecc_caps {
142 const int *strengths;
143 int nstrengths;
144 int el_offset;
145 bool correct_erased_chunks;
146 };
147
148 struct atmel_pmecc {
149 struct device *dev;
150 const struct atmel_pmecc_caps *caps;
151
152 struct {
153 void __iomem *base;
154 void __iomem *errloc;
155 } regs;
156
157 struct mutex lock;
158 };
159
160 struct atmel_pmecc_user_conf_cache {
161 u32 cfg;
162 u32 sarea;
163 u32 saddr;
164 u32 eaddr;
165 };
166
167 struct atmel_pmecc_user {
168 struct atmel_pmecc_user_conf_cache cache;
169 struct atmel_pmecc *pmecc;
170 const struct atmel_pmecc_gf_tables *gf_tables;
171 int eccbytes;
172 s16 *partial_syn;
173 s16 *si;
174 s16 *lmu;
175 s16 *smu;
176 s32 *mu;
177 s32 *dmu;
178 s32 *delta;
179 u32 isr;
180 };
181
182 static DEFINE_MUTEX(pmecc_gf_tables_lock);
183 static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_512;
184 static const struct atmel_pmecc_gf_tables *pmecc_gf_tables_1024;
185
deg(unsigned int poly)186 static inline int deg(unsigned int poly)
187 {
188 /* polynomial degree is the most-significant bit index */
189 return fls(poly) - 1;
190 }
191
atmel_pmecc_build_gf_tables(int mm,unsigned int poly,struct atmel_pmecc_gf_tables * gf_tables)192 static int atmel_pmecc_build_gf_tables(int mm, unsigned int poly,
193 struct atmel_pmecc_gf_tables *gf_tables)
194 {
195 unsigned int i, x = 1;
196 const unsigned int k = BIT(deg(poly));
197 unsigned int nn = BIT(mm) - 1;
198
199 /* primitive polynomial must be of degree m */
200 if (k != (1u << mm))
201 return -EINVAL;
202
203 for (i = 0; i < nn; i++) {
204 gf_tables->alpha_to[i] = x;
205 gf_tables->index_of[x] = i;
206 if (i && (x == 1))
207 /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */
208 return -EINVAL;
209 x <<= 1;
210 if (x & k)
211 x ^= poly;
212 }
213 gf_tables->alpha_to[nn] = 1;
214 gf_tables->index_of[0] = 0;
215
216 return 0;
217 }
218
219 static const struct atmel_pmecc_gf_tables *
atmel_pmecc_create_gf_tables(const struct atmel_pmecc_user_req * req)220 atmel_pmecc_create_gf_tables(const struct atmel_pmecc_user_req *req)
221 {
222 struct atmel_pmecc_gf_tables *gf_tables;
223 unsigned int poly, degree, table_size;
224 int ret;
225
226 if (req->ecc.sectorsize == 512) {
227 degree = PMECC_GF_DIMENSION_13;
228 poly = PMECC_GF_13_PRIMITIVE_POLY;
229 table_size = PMECC_LOOKUP_TABLE_SIZE_512;
230 } else {
231 degree = PMECC_GF_DIMENSION_14;
232 poly = PMECC_GF_14_PRIMITIVE_POLY;
233 table_size = PMECC_LOOKUP_TABLE_SIZE_1024;
234 }
235
236 gf_tables = kzalloc(sizeof(*gf_tables) +
237 (2 * table_size * sizeof(u16)),
238 GFP_KERNEL);
239 if (!gf_tables)
240 return ERR_PTR(-ENOMEM);
241
242 gf_tables->alpha_to = (void *)(gf_tables + 1);
243 gf_tables->index_of = gf_tables->alpha_to + table_size;
244
245 ret = atmel_pmecc_build_gf_tables(degree, poly, gf_tables);
246 if (ret) {
247 kfree(gf_tables);
248 return ERR_PTR(ret);
249 }
250
251 return gf_tables;
252 }
253
254 static const struct atmel_pmecc_gf_tables *
atmel_pmecc_get_gf_tables(const struct atmel_pmecc_user_req * req)255 atmel_pmecc_get_gf_tables(const struct atmel_pmecc_user_req *req)
256 {
257 const struct atmel_pmecc_gf_tables **gf_tables, *ret;
258
259 mutex_lock(&pmecc_gf_tables_lock);
260 if (req->ecc.sectorsize == 512)
261 gf_tables = &pmecc_gf_tables_512;
262 else
263 gf_tables = &pmecc_gf_tables_1024;
264
265 ret = *gf_tables;
266
267 if (!ret) {
268 ret = atmel_pmecc_create_gf_tables(req);
269 if (!IS_ERR(ret))
270 *gf_tables = ret;
271 }
272 mutex_unlock(&pmecc_gf_tables_lock);
273
274 return ret;
275 }
276
atmel_pmecc_prepare_user_req(struct atmel_pmecc * pmecc,struct atmel_pmecc_user_req * req)277 static int atmel_pmecc_prepare_user_req(struct atmel_pmecc *pmecc,
278 struct atmel_pmecc_user_req *req)
279 {
280 int i, max_eccbytes, eccbytes = 0, eccstrength = 0;
281
282 if (req->pagesize <= 0 || req->oobsize <= 0 || req->ecc.bytes <= 0)
283 return -EINVAL;
284
285 if (req->ecc.ooboffset >= 0 &&
286 req->ecc.ooboffset + req->ecc.bytes > req->oobsize)
287 return -EINVAL;
288
289 if (req->ecc.sectorsize == ATMEL_PMECC_SECTOR_SIZE_AUTO) {
290 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH)
291 return -EINVAL;
292
293 if (req->pagesize > 512)
294 req->ecc.sectorsize = 1024;
295 else
296 req->ecc.sectorsize = 512;
297 }
298
299 if (req->ecc.sectorsize != 512 && req->ecc.sectorsize != 1024)
300 return -EINVAL;
301
302 if (req->pagesize % req->ecc.sectorsize)
303 return -EINVAL;
304
305 req->ecc.nsectors = req->pagesize / req->ecc.sectorsize;
306
307 max_eccbytes = req->ecc.bytes;
308
309 for (i = 0; i < pmecc->caps->nstrengths; i++) {
310 int nbytes, strength = pmecc->caps->strengths[i];
311
312 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH &&
313 strength < req->ecc.strength)
314 continue;
315
316 nbytes = DIV_ROUND_UP(strength * fls(8 * req->ecc.sectorsize),
317 8);
318 nbytes *= req->ecc.nsectors;
319
320 if (nbytes > max_eccbytes)
321 break;
322
323 eccstrength = strength;
324 eccbytes = nbytes;
325
326 if (req->ecc.strength != ATMEL_PMECC_MAXIMIZE_ECC_STRENGTH)
327 break;
328 }
329
330 if (!eccstrength)
331 return -EINVAL;
332
333 req->ecc.bytes = eccbytes;
334 req->ecc.strength = eccstrength;
335
336 if (req->ecc.ooboffset < 0)
337 req->ecc.ooboffset = req->oobsize - eccbytes;
338
339 return 0;
340 }
341
342 struct atmel_pmecc_user *
atmel_pmecc_create_user(struct atmel_pmecc * pmecc,struct atmel_pmecc_user_req * req)343 atmel_pmecc_create_user(struct atmel_pmecc *pmecc,
344 struct atmel_pmecc_user_req *req)
345 {
346 struct atmel_pmecc_user *user;
347 const struct atmel_pmecc_gf_tables *gf_tables;
348 int strength, size, ret;
349
350 ret = atmel_pmecc_prepare_user_req(pmecc, req);
351 if (ret)
352 return ERR_PTR(ret);
353
354 size = sizeof(*user);
355 size = ALIGN(size, sizeof(u16));
356 /* Reserve space for partial_syn, si and smu */
357 size += ((2 * req->ecc.strength) + 1) * sizeof(u16) *
358 (2 + req->ecc.strength + 2);
359 /* Reserve space for lmu. */
360 size += (req->ecc.strength + 1) * sizeof(u16);
361 /* Reserve space for mu, dmu and delta. */
362 size = ALIGN(size, sizeof(s32));
363 size += (req->ecc.strength + 1) * sizeof(s32) * 3;
364
365 user = kzalloc(size, GFP_KERNEL);
366 if (!user)
367 return ERR_PTR(-ENOMEM);
368
369 user->pmecc = pmecc;
370
371 user->partial_syn = (s16 *)PTR_ALIGN(user + 1, sizeof(u16));
372 user->si = user->partial_syn + ((2 * req->ecc.strength) + 1);
373 user->lmu = user->si + ((2 * req->ecc.strength) + 1);
374 user->smu = user->lmu + (req->ecc.strength + 1);
375 user->mu = (s32 *)PTR_ALIGN(user->smu +
376 (((2 * req->ecc.strength) + 1) *
377 (req->ecc.strength + 2)),
378 sizeof(s32));
379 user->dmu = user->mu + req->ecc.strength + 1;
380 user->delta = user->dmu + req->ecc.strength + 1;
381
382 gf_tables = atmel_pmecc_get_gf_tables(req);
383 if (IS_ERR(gf_tables)) {
384 kfree(user);
385 return ERR_CAST(gf_tables);
386 }
387
388 user->gf_tables = gf_tables;
389
390 user->eccbytes = req->ecc.bytes / req->ecc.nsectors;
391
392 for (strength = 0; strength < pmecc->caps->nstrengths; strength++) {
393 if (pmecc->caps->strengths[strength] == req->ecc.strength)
394 break;
395 }
396
397 user->cache.cfg = PMECC_CFG_BCH_STRENGTH(strength) |
398 PMECC_CFG_NSECTORS(req->ecc.nsectors);
399
400 if (req->ecc.sectorsize == 1024)
401 user->cache.cfg |= PMECC_CFG_SECTOR1024;
402
403 user->cache.sarea = req->oobsize - 1;
404 user->cache.saddr = req->ecc.ooboffset;
405 user->cache.eaddr = req->ecc.ooboffset + req->ecc.bytes - 1;
406
407 return user;
408 }
409 EXPORT_SYMBOL_GPL(atmel_pmecc_create_user);
410
atmel_pmecc_destroy_user(struct atmel_pmecc_user * user)411 void atmel_pmecc_destroy_user(struct atmel_pmecc_user *user)
412 {
413 kfree(user);
414 }
415 EXPORT_SYMBOL_GPL(atmel_pmecc_destroy_user);
416
get_strength(struct atmel_pmecc_user * user)417 static int get_strength(struct atmel_pmecc_user *user)
418 {
419 const int *strengths = user->pmecc->caps->strengths;
420
421 return strengths[user->cache.cfg & PMECC_CFG_BCH_STRENGTH_MASK];
422 }
423
get_sectorsize(struct atmel_pmecc_user * user)424 static int get_sectorsize(struct atmel_pmecc_user *user)
425 {
426 return user->cache.cfg & PMECC_CFG_SECTOR1024 ? 1024 : 512;
427 }
428
atmel_pmecc_gen_syndrome(struct atmel_pmecc_user * user,int sector)429 static void atmel_pmecc_gen_syndrome(struct atmel_pmecc_user *user, int sector)
430 {
431 int strength = get_strength(user);
432 u32 value;
433 int i;
434
435 /* Fill odd syndromes */
436 for (i = 0; i < strength; i++) {
437 value = readl_relaxed(user->pmecc->regs.base +
438 ATMEL_PMECC_REM(sector, i / 2));
439 if (i & 1)
440 value >>= 16;
441
442 user->partial_syn[(2 * i) + 1] = value;
443 }
444 }
445
atmel_pmecc_substitute(struct atmel_pmecc_user * user)446 static void atmel_pmecc_substitute(struct atmel_pmecc_user *user)
447 {
448 int degree = get_sectorsize(user) == 512 ? 13 : 14;
449 int cw_len = BIT(degree) - 1;
450 int strength = get_strength(user);
451 s16 *alpha_to = user->gf_tables->alpha_to;
452 s16 *index_of = user->gf_tables->index_of;
453 s16 *partial_syn = user->partial_syn;
454 s16 *si;
455 int i, j;
456
457 /*
458 * si[] is a table that holds the current syndrome value,
459 * an element of that table belongs to the field
460 */
461 si = user->si;
462
463 memset(&si[1], 0, sizeof(s16) * ((2 * strength) - 1));
464
465 /* Computation 2t syndromes based on S(x) */
466 /* Odd syndromes */
467 for (i = 1; i < 2 * strength; i += 2) {
468 for (j = 0; j < degree; j++) {
469 if (partial_syn[i] & BIT(j))
470 si[i] = alpha_to[i * j] ^ si[i];
471 }
472 }
473 /* Even syndrome = (Odd syndrome) ** 2 */
474 for (i = 2, j = 1; j <= strength; i = ++j << 1) {
475 if (si[j] == 0) {
476 si[i] = 0;
477 } else {
478 s16 tmp;
479
480 tmp = index_of[si[j]];
481 tmp = (tmp * 2) % cw_len;
482 si[i] = alpha_to[tmp];
483 }
484 }
485 }
486
atmel_pmecc_get_sigma(struct atmel_pmecc_user * user)487 static void atmel_pmecc_get_sigma(struct atmel_pmecc_user *user)
488 {
489 s16 *lmu = user->lmu;
490 s16 *si = user->si;
491 s32 *mu = user->mu;
492 s32 *dmu = user->dmu;
493 s32 *delta = user->delta;
494 int degree = get_sectorsize(user) == 512 ? 13 : 14;
495 int cw_len = BIT(degree) - 1;
496 int strength = get_strength(user);
497 int num = 2 * strength + 1;
498 s16 *index_of = user->gf_tables->index_of;
499 s16 *alpha_to = user->gf_tables->alpha_to;
500 int i, j, k;
501 u32 dmu_0_count, tmp;
502 s16 *smu = user->smu;
503
504 /* index of largest delta */
505 int ro;
506 int largest;
507 int diff;
508
509 dmu_0_count = 0;
510
511 /* First Row */
512
513 /* Mu */
514 mu[0] = -1;
515
516 memset(smu, 0, sizeof(s16) * num);
517 smu[0] = 1;
518
519 /* discrepancy set to 1 */
520 dmu[0] = 1;
521 /* polynom order set to 0 */
522 lmu[0] = 0;
523 delta[0] = (mu[0] * 2 - lmu[0]) >> 1;
524
525 /* Second Row */
526
527 /* Mu */
528 mu[1] = 0;
529 /* Sigma(x) set to 1 */
530 memset(&smu[num], 0, sizeof(s16) * num);
531 smu[num] = 1;
532
533 /* discrepancy set to S1 */
534 dmu[1] = si[1];
535
536 /* polynom order set to 0 */
537 lmu[1] = 0;
538
539 delta[1] = (mu[1] * 2 - lmu[1]) >> 1;
540
541 /* Init the Sigma(x) last row */
542 memset(&smu[(strength + 1) * num], 0, sizeof(s16) * num);
543
544 for (i = 1; i <= strength; i++) {
545 mu[i + 1] = i << 1;
546 /* Begin Computing Sigma (Mu+1) and L(mu) */
547 /* check if discrepancy is set to 0 */
548 if (dmu[i] == 0) {
549 dmu_0_count++;
550
551 tmp = ((strength - (lmu[i] >> 1) - 1) / 2);
552 if ((strength - (lmu[i] >> 1) - 1) & 0x1)
553 tmp += 2;
554 else
555 tmp += 1;
556
557 if (dmu_0_count == tmp) {
558 for (j = 0; j <= (lmu[i] >> 1) + 1; j++)
559 smu[(strength + 1) * num + j] =
560 smu[i * num + j];
561
562 lmu[strength + 1] = lmu[i];
563 return;
564 }
565
566 /* copy polynom */
567 for (j = 0; j <= lmu[i] >> 1; j++)
568 smu[(i + 1) * num + j] = smu[i * num + j];
569
570 /* copy previous polynom order to the next */
571 lmu[i + 1] = lmu[i];
572 } else {
573 ro = 0;
574 largest = -1;
575 /* find largest delta with dmu != 0 */
576 for (j = 0; j < i; j++) {
577 if ((dmu[j]) && (delta[j] > largest)) {
578 largest = delta[j];
579 ro = j;
580 }
581 }
582
583 /* compute difference */
584 diff = (mu[i] - mu[ro]);
585
586 /* Compute degree of the new smu polynomial */
587 if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff))
588 lmu[i + 1] = lmu[i];
589 else
590 lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2;
591
592 /* Init smu[i+1] with 0 */
593 for (k = 0; k < num; k++)
594 smu[(i + 1) * num + k] = 0;
595
596 /* Compute smu[i+1] */
597 for (k = 0; k <= lmu[ro] >> 1; k++) {
598 s16 a, b, c;
599
600 if (!(smu[ro * num + k] && dmu[i]))
601 continue;
602
603 a = index_of[dmu[i]];
604 b = index_of[dmu[ro]];
605 c = index_of[smu[ro * num + k]];
606 tmp = a + (cw_len - b) + c;
607 a = alpha_to[tmp % cw_len];
608 smu[(i + 1) * num + (k + diff)] = a;
609 }
610
611 for (k = 0; k <= lmu[i] >> 1; k++)
612 smu[(i + 1) * num + k] ^= smu[i * num + k];
613 }
614
615 /* End Computing Sigma (Mu+1) and L(mu) */
616 /* In either case compute delta */
617 delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1;
618
619 /* Do not compute discrepancy for the last iteration */
620 if (i >= strength)
621 continue;
622
623 for (k = 0; k <= (lmu[i + 1] >> 1); k++) {
624 tmp = 2 * (i - 1);
625 if (k == 0) {
626 dmu[i + 1] = si[tmp + 3];
627 } else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) {
628 s16 a, b, c;
629
630 a = index_of[smu[(i + 1) * num + k]];
631 b = si[2 * (i - 1) + 3 - k];
632 c = index_of[b];
633 tmp = a + c;
634 tmp %= cw_len;
635 dmu[i + 1] = alpha_to[tmp] ^ dmu[i + 1];
636 }
637 }
638 }
639 }
640
atmel_pmecc_err_location(struct atmel_pmecc_user * user)641 static int atmel_pmecc_err_location(struct atmel_pmecc_user *user)
642 {
643 int sector_size = get_sectorsize(user);
644 int degree = sector_size == 512 ? 13 : 14;
645 struct atmel_pmecc *pmecc = user->pmecc;
646 int strength = get_strength(user);
647 int ret, roots_nbr, i, err_nbr = 0;
648 int num = (2 * strength) + 1;
649 s16 *smu = user->smu;
650 u32 val;
651
652 writel(PMERRLOC_DISABLE, pmecc->regs.errloc + ATMEL_PMERRLOC_ELDIS);
653
654 for (i = 0; i <= user->lmu[strength + 1] >> 1; i++) {
655 writel_relaxed(smu[(strength + 1) * num + i],
656 pmecc->regs.errloc + ATMEL_PMERRLOC_SIGMA(i));
657 err_nbr++;
658 }
659
660 val = (err_nbr - 1) << 16;
661 if (sector_size == 1024)
662 val |= 1;
663
664 writel(val, pmecc->regs.errloc + ATMEL_PMERRLOC_ELCFG);
665 writel((sector_size * 8) + (degree * strength),
666 pmecc->regs.errloc + ATMEL_PMERRLOC_ELEN);
667
668 ret = readl_relaxed_poll_timeout(pmecc->regs.errloc +
669 ATMEL_PMERRLOC_ELISR,
670 val, val & PMERRLOC_CALC_DONE, 0,
671 PMECC_MAX_TIMEOUT_MS * 1000);
672 if (ret) {
673 dev_err(pmecc->dev,
674 "PMECC: Timeout to calculate error location.\n");
675 return ret;
676 }
677
678 roots_nbr = (val & PMERRLOC_ERR_NUM_MASK) >> 8;
679 /* Number of roots == degree of smu hence <= cap */
680 if (roots_nbr == user->lmu[strength + 1] >> 1)
681 return err_nbr - 1;
682
683 /*
684 * Number of roots does not match the degree of smu
685 * unable to correct error.
686 */
687 return -EBADMSG;
688 }
689
atmel_pmecc_correct_sector(struct atmel_pmecc_user * user,int sector,void * data,void * ecc)690 int atmel_pmecc_correct_sector(struct atmel_pmecc_user *user, int sector,
691 void *data, void *ecc)
692 {
693 struct atmel_pmecc *pmecc = user->pmecc;
694 int sectorsize = get_sectorsize(user);
695 int eccbytes = user->eccbytes;
696 int i, nerrors;
697
698 if (!(user->isr & BIT(sector)))
699 return 0;
700
701 atmel_pmecc_gen_syndrome(user, sector);
702 atmel_pmecc_substitute(user);
703 atmel_pmecc_get_sigma(user);
704
705 nerrors = atmel_pmecc_err_location(user);
706 if (nerrors < 0)
707 return nerrors;
708
709 for (i = 0; i < nerrors; i++) {
710 const char *area;
711 int byte, bit;
712 u32 errpos;
713 u8 *ptr;
714
715 errpos = readl_relaxed(pmecc->regs.errloc +
716 ATMEL_PMERRLOC_EL(pmecc->caps->el_offset, i));
717 errpos--;
718
719 byte = errpos / 8;
720 bit = errpos % 8;
721
722 if (byte < sectorsize) {
723 ptr = data + byte;
724 area = "data";
725 } else if (byte < sectorsize + eccbytes) {
726 ptr = ecc + byte - sectorsize;
727 area = "ECC";
728 } else {
729 dev_dbg(pmecc->dev,
730 "Invalid errpos value (%d, max is %d)\n",
731 errpos, (sectorsize + eccbytes) * 8);
732 return -EINVAL;
733 }
734
735 dev_dbg(pmecc->dev,
736 "Bit flip in %s area, byte %d: 0x%02x -> 0x%02x\n",
737 area, byte, *ptr, (unsigned int)(*ptr ^ BIT(bit)));
738
739 *ptr ^= BIT(bit);
740 }
741
742 return nerrors;
743 }
744 EXPORT_SYMBOL_GPL(atmel_pmecc_correct_sector);
745
atmel_pmecc_correct_erased_chunks(struct atmel_pmecc_user * user)746 bool atmel_pmecc_correct_erased_chunks(struct atmel_pmecc_user *user)
747 {
748 return user->pmecc->caps->correct_erased_chunks;
749 }
750 EXPORT_SYMBOL_GPL(atmel_pmecc_correct_erased_chunks);
751
atmel_pmecc_get_generated_eccbytes(struct atmel_pmecc_user * user,int sector,void * ecc)752 void atmel_pmecc_get_generated_eccbytes(struct atmel_pmecc_user *user,
753 int sector, void *ecc)
754 {
755 struct atmel_pmecc *pmecc = user->pmecc;
756 u8 *ptr = ecc;
757 int i;
758
759 for (i = 0; i < user->eccbytes; i++)
760 ptr[i] = readb_relaxed(pmecc->regs.base +
761 ATMEL_PMECC_ECC(sector, i));
762 }
763 EXPORT_SYMBOL_GPL(atmel_pmecc_get_generated_eccbytes);
764
atmel_pmecc_reset(struct atmel_pmecc * pmecc)765 void atmel_pmecc_reset(struct atmel_pmecc *pmecc)
766 {
767 writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
768 writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
769 }
770 EXPORT_SYMBOL_GPL(atmel_pmecc_reset);
771
atmel_pmecc_enable(struct atmel_pmecc_user * user,int op)772 int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op)
773 {
774 struct atmel_pmecc *pmecc = user->pmecc;
775 u32 cfg;
776
777 if (op != NAND_ECC_READ && op != NAND_ECC_WRITE) {
778 dev_err(pmecc->dev, "Bad ECC operation!");
779 return -EINVAL;
780 }
781
782 mutex_lock(&user->pmecc->lock);
783
784 cfg = user->cache.cfg;
785 if (op == NAND_ECC_WRITE)
786 cfg |= PMECC_CFG_WRITE_OP;
787 else
788 cfg |= PMECC_CFG_AUTO_ENABLE;
789
790 writel(cfg, pmecc->regs.base + ATMEL_PMECC_CFG);
791 writel(user->cache.sarea, pmecc->regs.base + ATMEL_PMECC_SAREA);
792 writel(user->cache.saddr, pmecc->regs.base + ATMEL_PMECC_SADDR);
793 writel(user->cache.eaddr, pmecc->regs.base + ATMEL_PMECC_EADDR);
794
795 writel(PMECC_CTRL_ENABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
796 writel(PMECC_CTRL_DATA, pmecc->regs.base + ATMEL_PMECC_CTRL);
797
798 return 0;
799 }
800 EXPORT_SYMBOL_GPL(atmel_pmecc_enable);
801
atmel_pmecc_disable(struct atmel_pmecc_user * user)802 void atmel_pmecc_disable(struct atmel_pmecc_user *user)
803 {
804 atmel_pmecc_reset(user->pmecc);
805 mutex_unlock(&user->pmecc->lock);
806 }
807 EXPORT_SYMBOL_GPL(atmel_pmecc_disable);
808
atmel_pmecc_wait_rdy(struct atmel_pmecc_user * user)809 int atmel_pmecc_wait_rdy(struct atmel_pmecc_user *user)
810 {
811 struct atmel_pmecc *pmecc = user->pmecc;
812 u32 status;
813 int ret;
814
815 ret = readl_relaxed_poll_timeout(pmecc->regs.base +
816 ATMEL_PMECC_SR,
817 status, !(status & PMECC_SR_BUSY), 0,
818 PMECC_MAX_TIMEOUT_MS * 1000);
819 if (ret) {
820 dev_err(pmecc->dev,
821 "Timeout while waiting for PMECC ready.\n");
822 return ret;
823 }
824
825 user->isr = readl_relaxed(pmecc->regs.base + ATMEL_PMECC_ISR);
826
827 return 0;
828 }
829 EXPORT_SYMBOL_GPL(atmel_pmecc_wait_rdy);
830
atmel_pmecc_create(struct platform_device * pdev,const struct atmel_pmecc_caps * caps,int pmecc_res_idx,int errloc_res_idx)831 static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev,
832 const struct atmel_pmecc_caps *caps,
833 int pmecc_res_idx, int errloc_res_idx)
834 {
835 struct device *dev = &pdev->dev;
836 struct atmel_pmecc *pmecc;
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 pmecc->regs.base = devm_platform_ioremap_resource(pdev, pmecc_res_idx);
847 if (IS_ERR(pmecc->regs.base))
848 return ERR_CAST(pmecc->regs.base);
849
850 pmecc->regs.errloc = devm_platform_ioremap_resource(pdev, errloc_res_idx);
851 if (IS_ERR(pmecc->regs.errloc))
852 return ERR_CAST(pmecc->regs.errloc);
853
854 /* Disable all interrupts before registering the PMECC handler. */
855 writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR);
856 atmel_pmecc_reset(pmecc);
857
858 return pmecc;
859 }
860
devm_atmel_pmecc_put(struct device * dev,void * res)861 static void devm_atmel_pmecc_put(struct device *dev, void *res)
862 {
863 struct atmel_pmecc **pmecc = res;
864
865 put_device((*pmecc)->dev);
866 }
867
atmel_pmecc_get_by_node(struct device * userdev,struct device_node * np)868 static struct atmel_pmecc *atmel_pmecc_get_by_node(struct device *userdev,
869 struct device_node *np)
870 {
871 struct platform_device *pdev;
872 struct atmel_pmecc *pmecc, **ptr;
873 int ret;
874
875 pdev = of_find_device_by_node(np);
876 if (!pdev)
877 return ERR_PTR(-EPROBE_DEFER);
878 pmecc = platform_get_drvdata(pdev);
879 if (!pmecc) {
880 ret = -EPROBE_DEFER;
881 goto err_put_device;
882 }
883
884 ptr = devres_alloc(devm_atmel_pmecc_put, sizeof(*ptr), GFP_KERNEL);
885 if (!ptr) {
886 ret = -ENOMEM;
887 goto err_put_device;
888 }
889
890 *ptr = pmecc;
891
892 devres_add(userdev, ptr);
893
894 return pmecc;
895
896 err_put_device:
897 put_device(&pdev->dev);
898 return ERR_PTR(ret);
899 }
900
901 static const int atmel_pmecc_strengths[] = { 2, 4, 8, 12, 24, 32 };
902
903 static struct atmel_pmecc_caps at91sam9g45_caps = {
904 .strengths = atmel_pmecc_strengths,
905 .nstrengths = 5,
906 .el_offset = 0x8c,
907 };
908
909 static struct atmel_pmecc_caps sama5d4_caps = {
910 .strengths = atmel_pmecc_strengths,
911 .nstrengths = 5,
912 .el_offset = 0x8c,
913 .correct_erased_chunks = true,
914 };
915
916 static struct atmel_pmecc_caps sama5d2_caps = {
917 .strengths = atmel_pmecc_strengths,
918 .nstrengths = 6,
919 .el_offset = 0xac,
920 .correct_erased_chunks = true,
921 };
922
923 static const struct of_device_id __maybe_unused atmel_pmecc_legacy_match[] = {
924 { .compatible = "atmel,sama5d4-nand", &sama5d4_caps },
925 { .compatible = "atmel,sama5d2-nand", &sama5d2_caps },
926 { /* sentinel */ }
927 };
928
devm_atmel_pmecc_get(struct device * userdev)929 struct atmel_pmecc *devm_atmel_pmecc_get(struct device *userdev)
930 {
931 struct atmel_pmecc *pmecc;
932 struct device_node *np;
933
934 if (!userdev)
935 return ERR_PTR(-EINVAL);
936
937 if (!userdev->of_node)
938 return NULL;
939
940 np = of_parse_phandle(userdev->of_node, "ecc-engine", 0);
941 if (np) {
942 pmecc = atmel_pmecc_get_by_node(userdev, np);
943 of_node_put(np);
944 } else {
945 /*
946 * Support old DT bindings: in this case the PMECC iomem
947 * resources are directly defined in the user pdev at position
948 * 1 and 2. Extract all relevant information from there.
949 */
950 struct platform_device *pdev = to_platform_device(userdev);
951 const struct atmel_pmecc_caps *caps;
952 const struct of_device_id *match;
953
954 /* No PMECC engine available. */
955 if (!of_property_read_bool(userdev->of_node,
956 "atmel,has-pmecc"))
957 return NULL;
958
959 caps = &at91sam9g45_caps;
960
961 /* Find the caps associated to the NAND dev node. */
962 match = of_match_node(atmel_pmecc_legacy_match,
963 userdev->of_node);
964 if (match && match->data)
965 caps = match->data;
966
967 pmecc = atmel_pmecc_create(pdev, caps, 1, 2);
968 }
969
970 return pmecc;
971 }
972 EXPORT_SYMBOL(devm_atmel_pmecc_get);
973
974 static const struct of_device_id atmel_pmecc_match[] = {
975 { .compatible = "atmel,at91sam9g45-pmecc", &at91sam9g45_caps },
976 { .compatible = "atmel,sama5d4-pmecc", &sama5d4_caps },
977 { .compatible = "atmel,sama5d2-pmecc", &sama5d2_caps },
978 { /* sentinel */ }
979 };
980 MODULE_DEVICE_TABLE(of, atmel_pmecc_match);
981
atmel_pmecc_probe(struct platform_device * pdev)982 static int atmel_pmecc_probe(struct platform_device *pdev)
983 {
984 struct device *dev = &pdev->dev;
985 const struct atmel_pmecc_caps *caps;
986 struct atmel_pmecc *pmecc;
987
988 caps = of_device_get_match_data(&pdev->dev);
989 if (!caps) {
990 dev_err(dev, "Invalid caps\n");
991 return -EINVAL;
992 }
993
994 pmecc = atmel_pmecc_create(pdev, caps, 0, 1);
995 if (IS_ERR(pmecc))
996 return PTR_ERR(pmecc);
997
998 platform_set_drvdata(pdev, pmecc);
999
1000 return 0;
1001 }
1002
1003 static struct platform_driver atmel_pmecc_driver = {
1004 .driver = {
1005 .name = "atmel-pmecc",
1006 .of_match_table = atmel_pmecc_match,
1007 },
1008 .probe = atmel_pmecc_probe,
1009 };
1010 module_platform_driver(atmel_pmecc_driver);
1011
1012 MODULE_LICENSE("GPL");
1013 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
1014 MODULE_DESCRIPTION("PMECC engine driver");
1015 MODULE_ALIAS("platform:atmel_pmecc");
1016