treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61
[linux-block.git] / drivers / mtd / nand / raw / davinci_nand.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * davinci_nand.c - NAND Flash Driver for DaVinci family chips
4  *
5  * Copyright © 2006 Texas Instruments.
6  *
7  * Port to 2.6.23 Copyright © 2008 by:
8  *   Sander Huijsen <Shuijsen@optelecom-nkf.com>
9  *   Troy Kisky <troy.kisky@boundarydevices.com>
10  *   Dirk Behme <Dirk.Behme@gmail.com>
11  */
12
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/mtd/rawnand.h>
19 #include <linux/mtd/partitions.h>
20 #include <linux/slab.h>
21 #include <linux/of_device.h>
22 #include <linux/of.h>
23
24 #include <linux/platform_data/mtd-davinci.h>
25 #include <linux/platform_data/mtd-davinci-aemif.h>
26
27 /*
28  * This is a device driver for the NAND flash controller found on the
29  * various DaVinci family chips.  It handles up to four SoC chipselects,
30  * and some flavors of secondary chipselect (e.g. based on A12) as used
31  * with multichip packages.
32  *
33  * The 1-bit ECC hardware is supported, as well as the newer 4-bit ECC
34  * available on chips like the DM355 and OMAP-L137 and needed with the
35  * more error-prone MLC NAND chips.
36  *
37  * This driver assumes EM_WAIT connects all the NAND devices' RDY/nBUSY
38  * outputs in a "wire-AND" configuration, with no per-chip signals.
39  */
40 struct davinci_nand_info {
41         struct nand_chip        chip;
42
43         struct platform_device  *pdev;
44
45         bool                    is_readmode;
46
47         void __iomem            *base;
48         void __iomem            *vaddr;
49
50         void __iomem            *current_cs;
51
52         uint32_t                mask_chipsel;
53         uint32_t                mask_ale;
54         uint32_t                mask_cle;
55
56         uint32_t                core_chipsel;
57
58         struct davinci_aemif_timing     *timing;
59 };
60
61 static DEFINE_SPINLOCK(davinci_nand_lock);
62 static bool ecc4_busy;
63
64 static inline struct davinci_nand_info *to_davinci_nand(struct mtd_info *mtd)
65 {
66         return container_of(mtd_to_nand(mtd), struct davinci_nand_info, chip);
67 }
68
69 static inline unsigned int davinci_nand_readl(struct davinci_nand_info *info,
70                 int offset)
71 {
72         return __raw_readl(info->base + offset);
73 }
74
75 static inline void davinci_nand_writel(struct davinci_nand_info *info,
76                 int offset, unsigned long value)
77 {
78         __raw_writel(value, info->base + offset);
79 }
80
81 /*----------------------------------------------------------------------*/
82
83 /*
84  * Access to hardware control lines:  ALE, CLE, secondary chipselect.
85  */
86
87 static void nand_davinci_hwcontrol(struct nand_chip *nand, int cmd,
88                                    unsigned int ctrl)
89 {
90         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(nand));
91         void __iomem                    *addr = info->current_cs;
92
93         /* Did the control lines change? */
94         if (ctrl & NAND_CTRL_CHANGE) {
95                 if ((ctrl & NAND_CTRL_CLE) == NAND_CTRL_CLE)
96                         addr += info->mask_cle;
97                 else if ((ctrl & NAND_CTRL_ALE) == NAND_CTRL_ALE)
98                         addr += info->mask_ale;
99
100                 nand->legacy.IO_ADDR_W = addr;
101         }
102
103         if (cmd != NAND_CMD_NONE)
104                 iowrite8(cmd, nand->legacy.IO_ADDR_W);
105 }
106
107 static void nand_davinci_select_chip(struct nand_chip *nand, int chip)
108 {
109         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(nand));
110
111         info->current_cs = info->vaddr;
112
113         /* maybe kick in a second chipselect */
114         if (chip > 0)
115                 info->current_cs += info->mask_chipsel;
116
117         info->chip.legacy.IO_ADDR_W = info->current_cs;
118         info->chip.legacy.IO_ADDR_R = info->chip.legacy.IO_ADDR_W;
119 }
120
121 /*----------------------------------------------------------------------*/
122
123 /*
124  * 1-bit hardware ECC ... context maintained for each core chipselect
125  */
126
127 static inline uint32_t nand_davinci_readecc_1bit(struct mtd_info *mtd)
128 {
129         struct davinci_nand_info *info = to_davinci_nand(mtd);
130
131         return davinci_nand_readl(info, NANDF1ECC_OFFSET
132                         + 4 * info->core_chipsel);
133 }
134
135 static void nand_davinci_hwctl_1bit(struct nand_chip *chip, int mode)
136 {
137         struct davinci_nand_info *info;
138         uint32_t nandcfr;
139         unsigned long flags;
140
141         info = to_davinci_nand(nand_to_mtd(chip));
142
143         /* Reset ECC hardware */
144         nand_davinci_readecc_1bit(nand_to_mtd(chip));
145
146         spin_lock_irqsave(&davinci_nand_lock, flags);
147
148         /* Restart ECC hardware */
149         nandcfr = davinci_nand_readl(info, NANDFCR_OFFSET);
150         nandcfr |= BIT(8 + info->core_chipsel);
151         davinci_nand_writel(info, NANDFCR_OFFSET, nandcfr);
152
153         spin_unlock_irqrestore(&davinci_nand_lock, flags);
154 }
155
156 /*
157  * Read hardware ECC value and pack into three bytes
158  */
159 static int nand_davinci_calculate_1bit(struct nand_chip *chip,
160                                        const u_char *dat, u_char *ecc_code)
161 {
162         unsigned int ecc_val = nand_davinci_readecc_1bit(nand_to_mtd(chip));
163         unsigned int ecc24 = (ecc_val & 0x0fff) | ((ecc_val & 0x0fff0000) >> 4);
164
165         /* invert so that erased block ecc is correct */
166         ecc24 = ~ecc24;
167         ecc_code[0] = (u_char)(ecc24);
168         ecc_code[1] = (u_char)(ecc24 >> 8);
169         ecc_code[2] = (u_char)(ecc24 >> 16);
170
171         return 0;
172 }
173
174 static int nand_davinci_correct_1bit(struct nand_chip *chip, u_char *dat,
175                                      u_char *read_ecc, u_char *calc_ecc)
176 {
177         uint32_t eccNand = read_ecc[0] | (read_ecc[1] << 8) |
178                                           (read_ecc[2] << 16);
179         uint32_t eccCalc = calc_ecc[0] | (calc_ecc[1] << 8) |
180                                           (calc_ecc[2] << 16);
181         uint32_t diff = eccCalc ^ eccNand;
182
183         if (diff) {
184                 if ((((diff >> 12) ^ diff) & 0xfff) == 0xfff) {
185                         /* Correctable error */
186                         if ((diff >> (12 + 3)) < chip->ecc.size) {
187                                 dat[diff >> (12 + 3)] ^= BIT((diff >> 12) & 7);
188                                 return 1;
189                         } else {
190                                 return -EBADMSG;
191                         }
192                 } else if (!(diff & (diff - 1))) {
193                         /* Single bit ECC error in the ECC itself,
194                          * nothing to fix */
195                         return 1;
196                 } else {
197                         /* Uncorrectable error */
198                         return -EBADMSG;
199                 }
200
201         }
202         return 0;
203 }
204
205 /*----------------------------------------------------------------------*/
206
207 /*
208  * 4-bit hardware ECC ... context maintained over entire AEMIF
209  *
210  * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME
211  * since that forces use of a problematic "infix OOB" layout.
212  * Among other things, it trashes manufacturer bad block markers.
213  * Also, and specific to this hardware, it ECC-protects the "prepad"
214  * in the OOB ... while having ECC protection for parts of OOB would
215  * seem useful, the current MTD stack sometimes wants to update the
216  * OOB without recomputing ECC.
217  */
218
219 static void nand_davinci_hwctl_4bit(struct nand_chip *chip, int mode)
220 {
221         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip));
222         unsigned long flags;
223         u32 val;
224
225         /* Reset ECC hardware */
226         davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET);
227
228         spin_lock_irqsave(&davinci_nand_lock, flags);
229
230         /* Start 4-bit ECC calculation for read/write */
231         val = davinci_nand_readl(info, NANDFCR_OFFSET);
232         val &= ~(0x03 << 4);
233         val |= (info->core_chipsel << 4) | BIT(12);
234         davinci_nand_writel(info, NANDFCR_OFFSET, val);
235
236         info->is_readmode = (mode == NAND_ECC_READ);
237
238         spin_unlock_irqrestore(&davinci_nand_lock, flags);
239 }
240
241 /* Read raw ECC code after writing to NAND. */
242 static void
243 nand_davinci_readecc_4bit(struct davinci_nand_info *info, u32 code[4])
244 {
245         const u32 mask = 0x03ff03ff;
246
247         code[0] = davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET) & mask;
248         code[1] = davinci_nand_readl(info, NAND_4BIT_ECC2_OFFSET) & mask;
249         code[2] = davinci_nand_readl(info, NAND_4BIT_ECC3_OFFSET) & mask;
250         code[3] = davinci_nand_readl(info, NAND_4BIT_ECC4_OFFSET) & mask;
251 }
252
253 /* Terminate read ECC; or return ECC (as bytes) of data written to NAND. */
254 static int nand_davinci_calculate_4bit(struct nand_chip *chip,
255                                        const u_char *dat, u_char *ecc_code)
256 {
257         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip));
258         u32 raw_ecc[4], *p;
259         unsigned i;
260
261         /* After a read, terminate ECC calculation by a dummy read
262          * of some 4-bit ECC register.  ECC covers everything that
263          * was read; correct() just uses the hardware state, so
264          * ecc_code is not needed.
265          */
266         if (info->is_readmode) {
267                 davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET);
268                 return 0;
269         }
270
271         /* Pack eight raw 10-bit ecc values into ten bytes, making
272          * two passes which each convert four values (in upper and
273          * lower halves of two 32-bit words) into five bytes.  The
274          * ROM boot loader uses this same packing scheme.
275          */
276         nand_davinci_readecc_4bit(info, raw_ecc);
277         for (i = 0, p = raw_ecc; i < 2; i++, p += 2) {
278                 *ecc_code++ =   p[0]        & 0xff;
279                 *ecc_code++ = ((p[0] >>  8) & 0x03) | ((p[0] >> 14) & 0xfc);
280                 *ecc_code++ = ((p[0] >> 22) & 0x0f) | ((p[1] <<  4) & 0xf0);
281                 *ecc_code++ = ((p[1] >>  4) & 0x3f) | ((p[1] >> 10) & 0xc0);
282                 *ecc_code++ =  (p[1] >> 18) & 0xff;
283         }
284
285         return 0;
286 }
287
288 /* Correct up to 4 bits in data we just read, using state left in the
289  * hardware plus the ecc_code computed when it was first written.
290  */
291 static int nand_davinci_correct_4bit(struct nand_chip *chip, u_char *data,
292                                      u_char *ecc_code, u_char *null)
293 {
294         int i;
295         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip));
296         unsigned short ecc10[8];
297         unsigned short *ecc16;
298         u32 syndrome[4];
299         u32 ecc_state;
300         unsigned num_errors, corrected;
301         unsigned long timeo;
302
303         /* Unpack ten bytes into eight 10 bit values.  We know we're
304          * little-endian, and use type punning for less shifting/masking.
305          */
306         if (WARN_ON(0x01 & (uintptr_t)ecc_code))
307                 return -EINVAL;
308         ecc16 = (unsigned short *)ecc_code;
309
310         ecc10[0] =  (ecc16[0] >>  0) & 0x3ff;
311         ecc10[1] = ((ecc16[0] >> 10) & 0x3f) | ((ecc16[1] << 6) & 0x3c0);
312         ecc10[2] =  (ecc16[1] >>  4) & 0x3ff;
313         ecc10[3] = ((ecc16[1] >> 14) & 0x3)  | ((ecc16[2] << 2) & 0x3fc);
314         ecc10[4] =  (ecc16[2] >>  8)         | ((ecc16[3] << 8) & 0x300);
315         ecc10[5] =  (ecc16[3] >>  2) & 0x3ff;
316         ecc10[6] = ((ecc16[3] >> 12) & 0xf)  | ((ecc16[4] << 4) & 0x3f0);
317         ecc10[7] =  (ecc16[4] >>  6) & 0x3ff;
318
319         /* Tell ECC controller about the expected ECC codes. */
320         for (i = 7; i >= 0; i--)
321                 davinci_nand_writel(info, NAND_4BIT_ECC_LOAD_OFFSET, ecc10[i]);
322
323         /* Allow time for syndrome calculation ... then read it.
324          * A syndrome of all zeroes 0 means no detected errors.
325          */
326         davinci_nand_readl(info, NANDFSR_OFFSET);
327         nand_davinci_readecc_4bit(info, syndrome);
328         if (!(syndrome[0] | syndrome[1] | syndrome[2] | syndrome[3]))
329                 return 0;
330
331         /*
332          * Clear any previous address calculation by doing a dummy read of an
333          * error address register.
334          */
335         davinci_nand_readl(info, NAND_ERR_ADD1_OFFSET);
336
337         /* Start address calculation, and wait for it to complete.
338          * We _could_ start reading more data while this is working,
339          * to speed up the overall page read.
340          */
341         davinci_nand_writel(info, NANDFCR_OFFSET,
342                         davinci_nand_readl(info, NANDFCR_OFFSET) | BIT(13));
343
344         /*
345          * ECC_STATE field reads 0x3 (Error correction complete) immediately
346          * after setting the 4BITECC_ADD_CALC_START bit. So if you immediately
347          * begin trying to poll for the state, you may fall right out of your
348          * loop without any of the correction calculations having taken place.
349          * The recommendation from the hardware team is to initially delay as
350          * long as ECC_STATE reads less than 4. After that, ECC HW has entered
351          * correction state.
352          */
353         timeo = jiffies + usecs_to_jiffies(100);
354         do {
355                 ecc_state = (davinci_nand_readl(info,
356                                 NANDFSR_OFFSET) >> 8) & 0x0f;
357                 cpu_relax();
358         } while ((ecc_state < 4) && time_before(jiffies, timeo));
359
360         for (;;) {
361                 u32     fsr = davinci_nand_readl(info, NANDFSR_OFFSET);
362
363                 switch ((fsr >> 8) & 0x0f) {
364                 case 0:         /* no error, should not happen */
365                         davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
366                         return 0;
367                 case 1:         /* five or more errors detected */
368                         davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
369                         return -EBADMSG;
370                 case 2:         /* error addresses computed */
371                 case 3:
372                         num_errors = 1 + ((fsr >> 16) & 0x03);
373                         goto correct;
374                 default:        /* still working on it */
375                         cpu_relax();
376                         continue;
377                 }
378         }
379
380 correct:
381         /* correct each error */
382         for (i = 0, corrected = 0; i < num_errors; i++) {
383                 int error_address, error_value;
384
385                 if (i > 1) {
386                         error_address = davinci_nand_readl(info,
387                                                 NAND_ERR_ADD2_OFFSET);
388                         error_value = davinci_nand_readl(info,
389                                                 NAND_ERR_ERRVAL2_OFFSET);
390                 } else {
391                         error_address = davinci_nand_readl(info,
392                                                 NAND_ERR_ADD1_OFFSET);
393                         error_value = davinci_nand_readl(info,
394                                                 NAND_ERR_ERRVAL1_OFFSET);
395                 }
396
397                 if (i & 1) {
398                         error_address >>= 16;
399                         error_value >>= 16;
400                 }
401                 error_address &= 0x3ff;
402                 error_address = (512 + 7) - error_address;
403
404                 if (error_address < 512) {
405                         data[error_address] ^= error_value;
406                         corrected++;
407                 }
408         }
409
410         return corrected;
411 }
412
413 /*----------------------------------------------------------------------*/
414
415 /*
416  * NOTE:  NAND boot requires ALE == EM_A[1], CLE == EM_A[2], so that's
417  * how these chips are normally wired.  This translates to both 8 and 16
418  * bit busses using ALE == BIT(3) in byte addresses, and CLE == BIT(4).
419  *
420  * For now we assume that configuration, or any other one which ignores
421  * the two LSBs for NAND access ... so we can issue 32-bit reads/writes
422  * and have that transparently morphed into multiple NAND operations.
423  */
424 static void nand_davinci_read_buf(struct nand_chip *chip, uint8_t *buf,
425                                   int len)
426 {
427         if ((0x03 & ((uintptr_t)buf)) == 0 && (0x03 & len) == 0)
428                 ioread32_rep(chip->legacy.IO_ADDR_R, buf, len >> 2);
429         else if ((0x01 & ((uintptr_t)buf)) == 0 && (0x01 & len) == 0)
430                 ioread16_rep(chip->legacy.IO_ADDR_R, buf, len >> 1);
431         else
432                 ioread8_rep(chip->legacy.IO_ADDR_R, buf, len);
433 }
434
435 static void nand_davinci_write_buf(struct nand_chip *chip, const uint8_t *buf,
436                                    int len)
437 {
438         if ((0x03 & ((uintptr_t)buf)) == 0 && (0x03 & len) == 0)
439                 iowrite32_rep(chip->legacy.IO_ADDR_R, buf, len >> 2);
440         else if ((0x01 & ((uintptr_t)buf)) == 0 && (0x01 & len) == 0)
441                 iowrite16_rep(chip->legacy.IO_ADDR_R, buf, len >> 1);
442         else
443                 iowrite8_rep(chip->legacy.IO_ADDR_R, buf, len);
444 }
445
446 /*
447  * Check hardware register for wait status. Returns 1 if device is ready,
448  * 0 if it is still busy.
449  */
450 static int nand_davinci_dev_ready(struct nand_chip *chip)
451 {
452         struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip));
453
454         return davinci_nand_readl(info, NANDFSR_OFFSET) & BIT(0);
455 }
456
457 /*----------------------------------------------------------------------*/
458
459 /* An ECC layout for using 4-bit ECC with small-page flash, storing
460  * ten ECC bytes plus the manufacturer's bad block marker byte, and
461  * and not overlapping the default BBT markers.
462  */
463 static int hwecc4_ooblayout_small_ecc(struct mtd_info *mtd, int section,
464                                       struct mtd_oob_region *oobregion)
465 {
466         if (section > 2)
467                 return -ERANGE;
468
469         if (!section) {
470                 oobregion->offset = 0;
471                 oobregion->length = 5;
472         } else if (section == 1) {
473                 oobregion->offset = 6;
474                 oobregion->length = 2;
475         } else {
476                 oobregion->offset = 13;
477                 oobregion->length = 3;
478         }
479
480         return 0;
481 }
482
483 static int hwecc4_ooblayout_small_free(struct mtd_info *mtd, int section,
484                                        struct mtd_oob_region *oobregion)
485 {
486         if (section > 1)
487                 return -ERANGE;
488
489         if (!section) {
490                 oobregion->offset = 8;
491                 oobregion->length = 5;
492         } else {
493                 oobregion->offset = 16;
494                 oobregion->length = mtd->oobsize - 16;
495         }
496
497         return 0;
498 }
499
500 static const struct mtd_ooblayout_ops hwecc4_small_ooblayout_ops = {
501         .ecc = hwecc4_ooblayout_small_ecc,
502         .free = hwecc4_ooblayout_small_free,
503 };
504
505 #if defined(CONFIG_OF)
506 static const struct of_device_id davinci_nand_of_match[] = {
507         {.compatible = "ti,davinci-nand", },
508         {.compatible = "ti,keystone-nand", },
509         {},
510 };
511 MODULE_DEVICE_TABLE(of, davinci_nand_of_match);
512
513 static struct davinci_nand_pdata
514         *nand_davinci_get_pdata(struct platform_device *pdev)
515 {
516         if (!dev_get_platdata(&pdev->dev) && pdev->dev.of_node) {
517                 struct davinci_nand_pdata *pdata;
518                 const char *mode;
519                 u32 prop;
520
521                 pdata =  devm_kzalloc(&pdev->dev,
522                                 sizeof(struct davinci_nand_pdata),
523                                 GFP_KERNEL);
524                 pdev->dev.platform_data = pdata;
525                 if (!pdata)
526                         return ERR_PTR(-ENOMEM);
527                 if (!of_property_read_u32(pdev->dev.of_node,
528                         "ti,davinci-chipselect", &prop))
529                         pdata->core_chipsel = prop;
530                 else
531                         return ERR_PTR(-EINVAL);
532
533                 if (!of_property_read_u32(pdev->dev.of_node,
534                         "ti,davinci-mask-ale", &prop))
535                         pdata->mask_ale = prop;
536                 if (!of_property_read_u32(pdev->dev.of_node,
537                         "ti,davinci-mask-cle", &prop))
538                         pdata->mask_cle = prop;
539                 if (!of_property_read_u32(pdev->dev.of_node,
540                         "ti,davinci-mask-chipsel", &prop))
541                         pdata->mask_chipsel = prop;
542                 if (!of_property_read_string(pdev->dev.of_node,
543                         "ti,davinci-ecc-mode", &mode)) {
544                         if (!strncmp("none", mode, 4))
545                                 pdata->ecc_mode = NAND_ECC_NONE;
546                         if (!strncmp("soft", mode, 4))
547                                 pdata->ecc_mode = NAND_ECC_SOFT;
548                         if (!strncmp("hw", mode, 2))
549                                 pdata->ecc_mode = NAND_ECC_HW;
550                 }
551                 if (!of_property_read_u32(pdev->dev.of_node,
552                         "ti,davinci-ecc-bits", &prop))
553                         pdata->ecc_bits = prop;
554
555                 if (!of_property_read_u32(pdev->dev.of_node,
556                         "ti,davinci-nand-buswidth", &prop) && prop == 16)
557                         pdata->options |= NAND_BUSWIDTH_16;
558
559                 if (of_property_read_bool(pdev->dev.of_node,
560                         "ti,davinci-nand-use-bbt"))
561                         pdata->bbt_options = NAND_BBT_USE_FLASH;
562
563                 /*
564                  * Since kernel v4.8, this driver has been fixed to enable
565                  * use of 4-bit hardware ECC with subpages and verified on
566                  * TI's keystone EVMs (K2L, K2HK and K2E).
567                  * However, in the interest of not breaking systems using
568                  * existing UBI partitions, sub-page writes are not being
569                  * (re)enabled. If you want to use subpage writes on Keystone
570                  * platforms (i.e. do not have any existing UBI partitions),
571                  * then use "ti,davinci-nand" as the compatible in your
572                  * device-tree file.
573                  */
574                 if (of_device_is_compatible(pdev->dev.of_node,
575                                             "ti,keystone-nand")) {
576                         pdata->options |= NAND_NO_SUBPAGE_WRITE;
577                 }
578         }
579
580         return dev_get_platdata(&pdev->dev);
581 }
582 #else
583 static struct davinci_nand_pdata
584         *nand_davinci_get_pdata(struct platform_device *pdev)
585 {
586         return dev_get_platdata(&pdev->dev);
587 }
588 #endif
589
590 static int davinci_nand_attach_chip(struct nand_chip *chip)
591 {
592         struct mtd_info *mtd = nand_to_mtd(chip);
593         struct davinci_nand_info *info = to_davinci_nand(mtd);
594         struct davinci_nand_pdata *pdata = nand_davinci_get_pdata(info->pdev);
595         int ret = 0;
596
597         if (IS_ERR(pdata))
598                 return PTR_ERR(pdata);
599
600         switch (info->chip.ecc.mode) {
601         case NAND_ECC_NONE:
602                 pdata->ecc_bits = 0;
603                 break;
604         case NAND_ECC_SOFT:
605                 pdata->ecc_bits = 0;
606                 /*
607                  * This driver expects Hamming based ECC when ecc_mode is set
608                  * to NAND_ECC_SOFT. Force ecc.algo to NAND_ECC_HAMMING to
609                  * avoid adding an extra ->ecc_algo field to
610                  * davinci_nand_pdata.
611                  */
612                 info->chip.ecc.algo = NAND_ECC_HAMMING;
613                 break;
614         case NAND_ECC_HW:
615                 if (pdata->ecc_bits == 4) {
616                         /*
617                          * No sanity checks:  CPUs must support this,
618                          * and the chips may not use NAND_BUSWIDTH_16.
619                          */
620
621                         /* No sharing 4-bit hardware between chipselects yet */
622                         spin_lock_irq(&davinci_nand_lock);
623                         if (ecc4_busy)
624                                 ret = -EBUSY;
625                         else
626                                 ecc4_busy = true;
627                         spin_unlock_irq(&davinci_nand_lock);
628
629                         if (ret == -EBUSY)
630                                 return ret;
631
632                         info->chip.ecc.calculate = nand_davinci_calculate_4bit;
633                         info->chip.ecc.correct = nand_davinci_correct_4bit;
634                         info->chip.ecc.hwctl = nand_davinci_hwctl_4bit;
635                         info->chip.ecc.bytes = 10;
636                         info->chip.ecc.options = NAND_ECC_GENERIC_ERASED_CHECK;
637                         info->chip.ecc.algo = NAND_ECC_BCH;
638                 } else {
639                         /* 1bit ecc hamming */
640                         info->chip.ecc.calculate = nand_davinci_calculate_1bit;
641                         info->chip.ecc.correct = nand_davinci_correct_1bit;
642                         info->chip.ecc.hwctl = nand_davinci_hwctl_1bit;
643                         info->chip.ecc.bytes = 3;
644                         info->chip.ecc.algo = NAND_ECC_HAMMING;
645                 }
646                 info->chip.ecc.size = 512;
647                 info->chip.ecc.strength = pdata->ecc_bits;
648                 break;
649         default:
650                 return -EINVAL;
651         }
652
653         /*
654          * Update ECC layout if needed ... for 1-bit HW ECC, the default
655          * is OK, but it allocates 6 bytes when only 3 are needed (for
656          * each 512 bytes).  For the 4-bit HW ECC, that default is not
657          * usable:  10 bytes are needed, not 6.
658          */
659         if (pdata->ecc_bits == 4) {
660                 int chunks = mtd->writesize / 512;
661
662                 if (!chunks || mtd->oobsize < 16) {
663                         dev_dbg(&info->pdev->dev, "too small\n");
664                         return -EINVAL;
665                 }
666
667                 /* For small page chips, preserve the manufacturer's
668                  * badblock marking data ... and make sure a flash BBT
669                  * table marker fits in the free bytes.
670                  */
671                 if (chunks == 1) {
672                         mtd_set_ooblayout(mtd, &hwecc4_small_ooblayout_ops);
673                 } else if (chunks == 4 || chunks == 8) {
674                         mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
675                         info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST;
676                 } else {
677                         return -EIO;
678                 }
679         }
680
681         return ret;
682 }
683
684 static const struct nand_controller_ops davinci_nand_controller_ops = {
685         .attach_chip = davinci_nand_attach_chip,
686 };
687
688 static int nand_davinci_probe(struct platform_device *pdev)
689 {
690         struct davinci_nand_pdata       *pdata;
691         struct davinci_nand_info        *info;
692         struct resource                 *res1;
693         struct resource                 *res2;
694         void __iomem                    *vaddr;
695         void __iomem                    *base;
696         int                             ret;
697         uint32_t                        val;
698         struct mtd_info                 *mtd;
699
700         pdata = nand_davinci_get_pdata(pdev);
701         if (IS_ERR(pdata))
702                 return PTR_ERR(pdata);
703
704         /* insist on board-specific configuration */
705         if (!pdata)
706                 return -ENODEV;
707
708         /* which external chipselect will we be managing? */
709         if (pdata->core_chipsel < 0 || pdata->core_chipsel > 3)
710                 return -ENODEV;
711
712         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
713         if (!info)
714                 return -ENOMEM;
715
716         platform_set_drvdata(pdev, info);
717
718         res1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
719         res2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
720         if (!res1 || !res2) {
721                 dev_err(&pdev->dev, "resource missing\n");
722                 return -EINVAL;
723         }
724
725         vaddr = devm_ioremap_resource(&pdev->dev, res1);
726         if (IS_ERR(vaddr))
727                 return PTR_ERR(vaddr);
728
729         /*
730          * This registers range is used to setup NAND settings. In case with
731          * TI AEMIF driver, the same memory address range is requested already
732          * by AEMIF, so we cannot request it twice, just ioremap.
733          * The AEMIF and NAND drivers not use the same registers in this range.
734          */
735         base = devm_ioremap(&pdev->dev, res2->start, resource_size(res2));
736         if (!base) {
737                 dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res2);
738                 return -EADDRNOTAVAIL;
739         }
740
741         info->pdev              = pdev;
742         info->base              = base;
743         info->vaddr             = vaddr;
744
745         mtd                     = nand_to_mtd(&info->chip);
746         mtd->dev.parent         = &pdev->dev;
747         nand_set_flash_node(&info->chip, pdev->dev.of_node);
748
749         info->chip.legacy.IO_ADDR_R     = vaddr;
750         info->chip.legacy.IO_ADDR_W     = vaddr;
751         info->chip.legacy.chip_delay    = 0;
752         info->chip.legacy.select_chip   = nand_davinci_select_chip;
753
754         /* options such as NAND_BBT_USE_FLASH */
755         info->chip.bbt_options  = pdata->bbt_options;
756         /* options such as 16-bit widths */
757         info->chip.options      = pdata->options;
758         info->chip.bbt_td       = pdata->bbt_td;
759         info->chip.bbt_md       = pdata->bbt_md;
760         info->timing            = pdata->timing;
761
762         info->current_cs        = info->vaddr;
763         info->core_chipsel      = pdata->core_chipsel;
764         info->mask_chipsel      = pdata->mask_chipsel;
765
766         /* use nandboot-capable ALE/CLE masks by default */
767         info->mask_ale          = pdata->mask_ale ? : MASK_ALE;
768         info->mask_cle          = pdata->mask_cle ? : MASK_CLE;
769
770         /* Set address of hardware control function */
771         info->chip.legacy.cmd_ctrl      = nand_davinci_hwcontrol;
772         info->chip.legacy.dev_ready     = nand_davinci_dev_ready;
773
774         /* Speed up buffer I/O */
775         info->chip.legacy.read_buf     = nand_davinci_read_buf;
776         info->chip.legacy.write_buf    = nand_davinci_write_buf;
777
778         /* Use board-specific ECC config */
779         info->chip.ecc.mode     = pdata->ecc_mode;
780
781         spin_lock_irq(&davinci_nand_lock);
782
783         /* put CSxNAND into NAND mode */
784         val = davinci_nand_readl(info, NANDFCR_OFFSET);
785         val |= BIT(info->core_chipsel);
786         davinci_nand_writel(info, NANDFCR_OFFSET, val);
787
788         spin_unlock_irq(&davinci_nand_lock);
789
790         /* Scan to find existence of the device(s) */
791         info->chip.legacy.dummy_controller.ops = &davinci_nand_controller_ops;
792         ret = nand_scan(&info->chip, pdata->mask_chipsel ? 2 : 1);
793         if (ret < 0) {
794                 dev_dbg(&pdev->dev, "no NAND chip(s) found\n");
795                 return ret;
796         }
797
798         if (pdata->parts)
799                 ret = mtd_device_register(mtd, pdata->parts, pdata->nr_parts);
800         else
801                 ret = mtd_device_register(mtd, NULL, 0);
802         if (ret < 0)
803                 goto err_cleanup_nand;
804
805         val = davinci_nand_readl(info, NRCSR_OFFSET);
806         dev_info(&pdev->dev, "controller rev. %d.%d\n",
807                (val >> 8) & 0xff, val & 0xff);
808
809         return 0;
810
811 err_cleanup_nand:
812         nand_cleanup(&info->chip);
813
814         return ret;
815 }
816
817 static int nand_davinci_remove(struct platform_device *pdev)
818 {
819         struct davinci_nand_info *info = platform_get_drvdata(pdev);
820
821         spin_lock_irq(&davinci_nand_lock);
822         if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME)
823                 ecc4_busy = false;
824         spin_unlock_irq(&davinci_nand_lock);
825
826         nand_release(&info->chip);
827
828         return 0;
829 }
830
831 static struct platform_driver nand_davinci_driver = {
832         .probe          = nand_davinci_probe,
833         .remove         = nand_davinci_remove,
834         .driver         = {
835                 .name   = "davinci_nand",
836                 .of_match_table = of_match_ptr(davinci_nand_of_match),
837         },
838 };
839 MODULE_ALIAS("platform:davinci_nand");
840
841 module_platform_driver(nand_davinci_driver);
842
843 MODULE_LICENSE("GPL");
844 MODULE_AUTHOR("Texas Instruments");
845 MODULE_DESCRIPTION("Davinci NAND flash driver");
846