Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/drivers/mtd/nand/gpmi-nand/gpmi-nand.c

  1 /*
  2  * Freescale GPMI NAND Flash Driver
  3  *
  4  * Copyright (C) 2010-2015 Freescale Semiconductor, Inc.
  5  * Copyright (C) 2008 Embedded Alley Solutions, Inc.
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License as published by
  9  * the Free Software Foundation; either version 2 of the License, or
 10  * (at your option) any later version.
 11  *
 12  * This program is distributed in the hope that it will be useful,
 13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15  * GNU General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU General Public License along
 18  * with this program; if not, write to the Free Software Foundation, Inc.,
 19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 20  */
 21 #include <linux/clk.h>
 22 #include <linux/slab.h>
 23 #include <linux/interrupt.h>
 24 #include <linux/module.h>
 25 #include <linux/mtd/partitions.h>
 26 #include <linux/of.h>
 27 #include <linux/of_device.h>
 28 #include "gpmi-nand.h"
 29 #include "bch-regs.h"
 30 
 31 /* Resource names for the GPMI NAND driver. */
 32 #define GPMI_NAND_GPMI_REGS_ADDR_RES_NAME  "gpmi-nand"
 33 #define GPMI_NAND_BCH_REGS_ADDR_RES_NAME   "bch"
 34 #define GPMI_NAND_BCH_INTERRUPT_RES_NAME   "bch"
 35 
 36 /* add our owner bbt descriptor */
 37 static uint8_t scan_ff_pattern[] = { 0xff };
 38 static struct nand_bbt_descr gpmi_bbt_descr = {
 39         .options        = 0,
 40         .offs           = 0,
 41         .len            = 1,
 42         .pattern        = scan_ff_pattern
 43 };
 44 
 45 /*
 46  * We may change the layout if we can get the ECC info from the datasheet,
 47  * else we will use all the (page + OOB).
 48  */
 49 static int gpmi_ooblayout_ecc(struct mtd_info *mtd, int section,
 50                               struct mtd_oob_region *oobregion)
 51 {
 52         struct nand_chip *chip = mtd_to_nand(mtd);
 53         struct gpmi_nand_data *this = nand_get_controller_data(chip);
 54         struct bch_geometry *geo = &this->bch_geometry;
 55 
 56         if (section)
 57                 return -ERANGE;
 58 
 59         oobregion->offset = 0;
 60         oobregion->length = geo->page_size - mtd->writesize;
 61 
 62         return 0;
 63 }
 64 
 65 static int gpmi_ooblayout_free(struct mtd_info *mtd, int section,
 66                                struct mtd_oob_region *oobregion)
 67 {
 68         struct nand_chip *chip = mtd_to_nand(mtd);
 69         struct gpmi_nand_data *this = nand_get_controller_data(chip);
 70         struct bch_geometry *geo = &this->bch_geometry;
 71 
 72         if (section)
 73                 return -ERANGE;
 74 
 75         /* The available oob size we have. */
 76         if (geo->page_size < mtd->writesize + mtd->oobsize) {
 77                 oobregion->offset = geo->page_size - mtd->writesize;
 78                 oobregion->length = mtd->oobsize - oobregion->offset;
 79         }
 80 
 81         return 0;
 82 }
 83 
 84 static const struct mtd_ooblayout_ops gpmi_ooblayout_ops = {
 85         .ecc = gpmi_ooblayout_ecc,
 86         .free = gpmi_ooblayout_free,
 87 };
 88 
 89 static const struct gpmi_devdata gpmi_devdata_imx23 = {
 90         .type = IS_MX23,
 91         .bch_max_ecc_strength = 20,
 92         .max_chain_delay = 16,
 93 };
 94 
 95 static const struct gpmi_devdata gpmi_devdata_imx28 = {
 96         .type = IS_MX28,
 97         .bch_max_ecc_strength = 20,
 98         .max_chain_delay = 16,
 99 };
100 
101 static const struct gpmi_devdata gpmi_devdata_imx6q = {
102         .type = IS_MX6Q,
103         .bch_max_ecc_strength = 40,
104         .max_chain_delay = 12,
105 };
106 
107 static const struct gpmi_devdata gpmi_devdata_imx6sx = {
108         .type = IS_MX6SX,
109         .bch_max_ecc_strength = 62,
110         .max_chain_delay = 12,
111 };
112 
113 static irqreturn_t bch_irq(int irq, void *cookie)
114 {
115         struct gpmi_nand_data *this = cookie;
116 
117         gpmi_clear_bch(this);
118         complete(&this->bch_done);
119         return IRQ_HANDLED;
120 }
121 
122 /*
123  *  Calculate the ECC strength by hand:
124  *      E : The ECC strength.
125  *      G : the length of Galois Field.
126  *      N : The chunk count of per page.
127  *      O : the oobsize of the NAND chip.
128  *      M : the metasize of per page.
129  *
130  *      The formula is :
131  *              E * G * N
132  *            ------------ <= (O - M)
133  *                  8
134  *
135  *      So, we get E by:
136  *                    (O - M) * 8
137  *              E <= -------------
138  *                       G * N
139  */
140 static inline int get_ecc_strength(struct gpmi_nand_data *this)
141 {
142         struct bch_geometry *geo = &this->bch_geometry;
143         struct mtd_info *mtd = nand_to_mtd(&this->nand);
144         int ecc_strength;
145 
146         ecc_strength = ((mtd->oobsize - geo->metadata_size) * 8)
147                         / (geo->gf_len * geo->ecc_chunk_count);
148 
149         /* We need the minor even number. */
150         return round_down(ecc_strength, 2);
151 }
152 
153 static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
154 {
155         struct bch_geometry *geo = &this->bch_geometry;
156 
157         /* Do the sanity check. */
158         if (GPMI_IS_MX23(this) || GPMI_IS_MX28(this)) {
159                 /* The mx23/mx28 only support the GF13. */
160                 if (geo->gf_len == 14)
161                         return false;
162         }
163         return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
164 }
165 
166 /*
167  * If we can get the ECC information from the nand chip, we do not
168  * need to calculate them ourselves.
169  *
170  * We may have available oob space in this case.
171  */
172 static int set_geometry_by_ecc_info(struct gpmi_nand_data *this)
173 {
174         struct bch_geometry *geo = &this->bch_geometry;
175         struct nand_chip *chip = &this->nand;
176         struct mtd_info *mtd = nand_to_mtd(chip);
177         unsigned int block_mark_bit_offset;
178 
179         if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0))
180                 return -EINVAL;
181 
182         switch (chip->ecc_step_ds) {
183         case SZ_512:
184                 geo->gf_len = 13;
185                 break;
186         case SZ_1K:
187                 geo->gf_len = 14;
188                 break;
189         default:
190                 dev_err(this->dev,
191                         "unsupported nand chip. ecc bits : %d, ecc size : %d\n",
192                         chip->ecc_strength_ds, chip->ecc_step_ds);
193                 return -EINVAL;
194         }
195         geo->ecc_chunk_size = chip->ecc_step_ds;
196         geo->ecc_strength = round_up(chip->ecc_strength_ds, 2);
197         if (!gpmi_check_ecc(this))
198                 return -EINVAL;
199 
200         /* Keep the C >= O */
201         if (geo->ecc_chunk_size < mtd->oobsize) {
202                 dev_err(this->dev,
203                         "unsupported nand chip. ecc size: %d, oob size : %d\n",
204                         chip->ecc_step_ds, mtd->oobsize);
205                 return -EINVAL;
206         }
207 
208         /* The default value, see comment in the legacy_set_geometry(). */
209         geo->metadata_size = 10;
210 
211         geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
212 
213         /*
214          * Now, the NAND chip with 2K page(data chunk is 512byte) shows below:
215          *
216          *    |                          P                            |
217          *    |<----------------------------------------------------->|
218          *    |                                                       |
219          *    |                                        (Block Mark)   |
220          *    |                      P'                      |      | |     |
221          *    |<-------------------------------------------->|  D   | |  O' |
222          *    |                                              |<---->| |<--->|
223          *    V                                              V      V V     V
224          *    +---+----------+-+----------+-+----------+-+----------+-+-----+
225          *    | M |   data   |E|   data   |E|   data   |E|   data   |E|     |
226          *    +---+----------+-+----------+-+----------+-+----------+-+-----+
227          *                                                   ^              ^
228          *                                                   |      O       |
229          *                                                   |<------------>|
230          *                                                   |              |
231          *
232          *      P : the page size for BCH module.
233          *      E : The ECC strength.
234          *      G : the length of Galois Field.
235          *      N : The chunk count of per page.
236          *      M : the metasize of per page.
237          *      C : the ecc chunk size, aka the "data" above.
238          *      P': the nand chip's page size.
239          *      O : the nand chip's oob size.
240          *      O': the free oob.
241          *
242          *      The formula for P is :
243          *
244          *                  E * G * N
245          *             P = ------------ + P' + M
246          *                      8
247          *
248          * The position of block mark moves forward in the ECC-based view
249          * of page, and the delta is:
250          *
251          *                   E * G * (N - 1)
252          *             D = (---------------- + M)
253          *                          8
254          *
255          * Please see the comment in legacy_set_geometry().
256          * With the condition C >= O , we still can get same result.
257          * So the bit position of the physical block mark within the ECC-based
258          * view of the page is :
259          *             (P' - D) * 8
260          */
261         geo->page_size = mtd->writesize + geo->metadata_size +
262                 (geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
263 
264         geo->payload_size = mtd->writesize;
265 
266         geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
267         geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
268                                 + ALIGN(geo->ecc_chunk_count, 4);
269 
270         if (!this->swap_block_mark)
271                 return 0;
272 
273         /* For bit swap. */
274         block_mark_bit_offset = mtd->writesize * 8 -
275                 (geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
276                                 + geo->metadata_size * 8);
277 
278         geo->block_mark_byte_offset = block_mark_bit_offset / 8;
279         geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
280         return 0;
281 }
282 
283 static int legacy_set_geometry(struct gpmi_nand_data *this)
284 {
285         struct bch_geometry *geo = &this->bch_geometry;
286         struct mtd_info *mtd = nand_to_mtd(&this->nand);
287         unsigned int metadata_size;
288         unsigned int status_size;
289         unsigned int block_mark_bit_offset;
290 
291         /*
292          * The size of the metadata can be changed, though we set it to 10
293          * bytes now. But it can't be too large, because we have to save
294          * enough space for BCH.
295          */
296         geo->metadata_size = 10;
297 
298         /* The default for the length of Galois Field. */
299         geo->gf_len = 13;
300 
301         /* The default for chunk size. */
302         geo->ecc_chunk_size = 512;
303         while (geo->ecc_chunk_size < mtd->oobsize) {
304                 geo->ecc_chunk_size *= 2; /* keep C >= O */
305                 geo->gf_len = 14;
306         }
307 
308         geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
309 
310         /* We use the same ECC strength for all chunks. */
311         geo->ecc_strength = get_ecc_strength(this);
312         if (!gpmi_check_ecc(this)) {
313                 dev_err(this->dev,
314                         "ecc strength: %d cannot be supported by the controller (%d)\n"
315                         "try to use minimum ecc strength that NAND chip required\n",
316                         geo->ecc_strength,
317                         this->devdata->bch_max_ecc_strength);
318                 return -EINVAL;
319         }
320 
321         geo->page_size = mtd->writesize + geo->metadata_size +
322                 (geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
323         geo->payload_size = mtd->writesize;
324 
325         /*
326          * The auxiliary buffer contains the metadata and the ECC status. The
327          * metadata is padded to the nearest 32-bit boundary. The ECC status
328          * contains one byte for every ECC chunk, and is also padded to the
329          * nearest 32-bit boundary.
330          */
331         metadata_size = ALIGN(geo->metadata_size, 4);
332         status_size   = ALIGN(geo->ecc_chunk_count, 4);
333 
334         geo->auxiliary_size = metadata_size + status_size;
335         geo->auxiliary_status_offset = metadata_size;
336 
337         if (!this->swap_block_mark)
338                 return 0;
339 
340         /*
341          * We need to compute the byte and bit offsets of
342          * the physical block mark within the ECC-based view of the page.
343          *
344          * NAND chip with 2K page shows below:
345          *                                             (Block Mark)
346          *                                                   |      |
347          *                                                   |  D   |
348          *                                                   |<---->|
349          *                                                   V      V
350          *    +---+----------+-+----------+-+----------+-+----------+-+
351          *    | M |   data   |E|   data   |E|   data   |E|   data   |E|
352          *    +---+----------+-+----------+-+----------+-+----------+-+
353          *
354          * The position of block mark moves forward in the ECC-based view
355          * of page, and the delta is:
356          *
357          *                   E * G * (N - 1)
358          *             D = (---------------- + M)
359          *                          8
360          *
361          * With the formula to compute the ECC strength, and the condition
362          *       : C >= O         (C is the ecc chunk size)
363          *
364          * It's easy to deduce to the following result:
365          *
366          *         E * G       (O - M)      C - M         C - M
367          *      ----------- <= ------- <=  --------  <  ---------
368          *           8            N           N          (N - 1)
369          *
370          *  So, we get:
371          *
372          *                   E * G * (N - 1)
373          *             D = (---------------- + M) < C
374          *                          8
375          *
376          *  The above inequality means the position of block mark
377          *  within the ECC-based view of the page is still in the data chunk,
378          *  and it's NOT in the ECC bits of the chunk.
379          *
380          *  Use the following to compute the bit position of the
381          *  physical block mark within the ECC-based view of the page:
382          *          (page_size - D) * 8
383          *
384          *  --Huang Shijie
385          */
386         block_mark_bit_offset = mtd->writesize * 8 -
387                 (geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
388                                 + geo->metadata_size * 8);
389 
390         geo->block_mark_byte_offset = block_mark_bit_offset / 8;
391         geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
392         return 0;
393 }
394 
395 int common_nfc_set_geometry(struct gpmi_nand_data *this)
396 {
397         if ((of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
398                                 || legacy_set_geometry(this))
399                 return set_geometry_by_ecc_info(this);
400 
401         return 0;
402 }
403 
404 struct dma_chan *get_dma_chan(struct gpmi_nand_data *this)
405 {
406         /* We use the DMA channel 0 to access all the nand chips. */
407         return this->dma_chans[0];
408 }
409 
410 /* Can we use the upper's buffer directly for DMA? */
411 void prepare_data_dma(struct gpmi_nand_data *this, enum dma_data_direction dr)
412 {
413         struct scatterlist *sgl = &this->data_sgl;
414         int ret;
415 
416         /* first try to map the upper buffer directly */
417         if (virt_addr_valid(this->upper_buf) &&
418                 !object_is_on_stack(this->upper_buf)) {
419                 sg_init_one(sgl, this->upper_buf, this->upper_len);
420                 ret = dma_map_sg(this->dev, sgl, 1, dr);
421                 if (ret == 0)
422                         goto map_fail;
423 
424                 this->direct_dma_map_ok = true;
425                 return;
426         }
427 
428 map_fail:
429         /* We have to use our own DMA buffer. */
430         sg_init_one(sgl, this->data_buffer_dma, this->upper_len);
431 
432         if (dr == DMA_TO_DEVICE)
433                 memcpy(this->data_buffer_dma, this->upper_buf, this->upper_len);
434 
435         dma_map_sg(this->dev, sgl, 1, dr);
436 
437         this->direct_dma_map_ok = false;
438 }
439 
440 /* This will be called after the DMA operation is finished. */
441 static void dma_irq_callback(void *param)
442 {
443         struct gpmi_nand_data *this = param;
444         struct completion *dma_c = &this->dma_done;
445 
446         switch (this->dma_type) {
447         case DMA_FOR_COMMAND:
448                 dma_unmap_sg(this->dev, &this->cmd_sgl, 1, DMA_TO_DEVICE);
449                 break;
450 
451         case DMA_FOR_READ_DATA:
452                 dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_FROM_DEVICE);
453                 if (this->direct_dma_map_ok == false)
454                         memcpy(this->upper_buf, this->data_buffer_dma,
455                                 this->upper_len);
456                 break;
457 
458         case DMA_FOR_WRITE_DATA:
459                 dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_TO_DEVICE);
460                 break;
461 
462         case DMA_FOR_READ_ECC_PAGE:
463         case DMA_FOR_WRITE_ECC_PAGE:
464                 /* We have to wait the BCH interrupt to finish. */
465                 break;
466 
467         default:
468                 dev_err(this->dev, "in wrong DMA operation.\n");
469         }
470 
471         complete(dma_c);
472 }
473 
474 int start_dma_without_bch_irq(struct gpmi_nand_data *this,
475                                 struct dma_async_tx_descriptor *desc)
476 {
477         struct completion *dma_c = &this->dma_done;
478         unsigned long timeout;
479 
480         init_completion(dma_c);
481 
482         desc->callback          = dma_irq_callback;
483         desc->callback_param    = this;
484         dmaengine_submit(desc);
485         dma_async_issue_pending(get_dma_chan(this));
486 
487         /* Wait for the interrupt from the DMA block. */
488         timeout = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
489         if (!timeout) {
490                 dev_err(this->dev, "DMA timeout, last DMA :%d\n",
491                         this->last_dma_type);
492                 gpmi_dump_info(this);
493                 return -ETIMEDOUT;
494         }
495         return 0;
496 }
497 
498 /*
499  * This function is used in BCH reading or BCH writing pages.
500  * It will wait for the BCH interrupt as long as ONE second.
501  * Actually, we must wait for two interrupts :
502  *      [1] firstly the DMA interrupt and
503  *      [2] secondly the BCH interrupt.
504  */
505 int start_dma_with_bch_irq(struct gpmi_nand_data *this,
506                         struct dma_async_tx_descriptor *desc)
507 {
508         struct completion *bch_c = &this->bch_done;
509         unsigned long timeout;
510 
511         /* Prepare to receive an interrupt from the BCH block. */
512         init_completion(bch_c);
513 
514         /* start the DMA */
515         start_dma_without_bch_irq(this, desc);
516 
517         /* Wait for the interrupt from the BCH block. */
518         timeout = wait_for_completion_timeout(bch_c, msecs_to_jiffies(1000));
519         if (!timeout) {
520                 dev_err(this->dev, "BCH timeout, last DMA :%d\n",
521                         this->last_dma_type);
522                 gpmi_dump_info(this);
523                 return -ETIMEDOUT;
524         }
525         return 0;
526 }
527 
528 static int acquire_register_block(struct gpmi_nand_data *this,
529                                   const char *res_name)
530 {
531         struct platform_device *pdev = this->pdev;
532         struct resources *res = &this->resources;
533         struct resource *r;
534         void __iomem *p;
535 
536         r = platform_get_resource_byname(pdev, IORESOURCE_MEM, res_name);
537         p = devm_ioremap_resource(&pdev->dev, r);
538         if (IS_ERR(p))
539                 return PTR_ERR(p);
540 
541         if (!strcmp(res_name, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME))
542                 res->gpmi_regs = p;
543         else if (!strcmp(res_name, GPMI_NAND_BCH_REGS_ADDR_RES_NAME))
544                 res->bch_regs = p;
545         else
546                 dev_err(this->dev, "unknown resource name : %s\n", res_name);
547 
548         return 0;
549 }
550 
551 static int acquire_bch_irq(struct gpmi_nand_data *this, irq_handler_t irq_h)
552 {
553         struct platform_device *pdev = this->pdev;
554         const char *res_name = GPMI_NAND_BCH_INTERRUPT_RES_NAME;
555         struct resource *r;
556         int err;
557 
558         r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, res_name);
559         if (!r) {
560                 dev_err(this->dev, "Can't get resource for %s\n", res_name);
561                 return -ENODEV;
562         }
563 
564         err = devm_request_irq(this->dev, r->start, irq_h, 0, res_name, this);
565         if (err)
566                 dev_err(this->dev, "error requesting BCH IRQ\n");
567 
568         return err;
569 }
570 
571 static void release_dma_channels(struct gpmi_nand_data *this)
572 {
573         unsigned int i;
574         for (i = 0; i < DMA_CHANS; i++)
575                 if (this->dma_chans[i]) {
576                         dma_release_channel(this->dma_chans[i]);
577                         this->dma_chans[i] = NULL;
578                 }
579 }
580 
581 static int acquire_dma_channels(struct gpmi_nand_data *this)
582 {
583         struct platform_device *pdev = this->pdev;
584         struct dma_chan *dma_chan;
585 
586         /* request dma channel */
587         dma_chan = dma_request_slave_channel(&pdev->dev, "rx-tx");
588         if (!dma_chan) {
589                 dev_err(this->dev, "Failed to request DMA channel.\n");
590                 goto acquire_err;
591         }
592 
593         this->dma_chans[0] = dma_chan;
594         return 0;
595 
596 acquire_err:
597         release_dma_channels(this);
598         return -EINVAL;
599 }
600 
601 static char *extra_clks_for_mx6q[GPMI_CLK_MAX] = {
602         "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
603 };
604 
605 static int gpmi_get_clks(struct gpmi_nand_data *this)
606 {
607         struct resources *r = &this->resources;
608         char **extra_clks = NULL;
609         struct clk *clk;
610         int err, i;
611 
612         /* The main clock is stored in the first. */
613         r->clock[0] = devm_clk_get(this->dev, "gpmi_io");
614         if (IS_ERR(r->clock[0])) {
615                 err = PTR_ERR(r->clock[0]);
616                 goto err_clock;
617         }
618 
619         /* Get extra clocks */
620         if (GPMI_IS_MX6(this))
621                 extra_clks = extra_clks_for_mx6q;
622         if (!extra_clks)
623                 return 0;
624 
625         for (i = 1; i < GPMI_CLK_MAX; i++) {
626                 if (extra_clks[i - 1] == NULL)
627                         break;
628 
629                 clk = devm_clk_get(this->dev, extra_clks[i - 1]);
630                 if (IS_ERR(clk)) {
631                         err = PTR_ERR(clk);
632                         goto err_clock;
633                 }
634 
635                 r->clock[i] = clk;
636         }
637 
638         if (GPMI_IS_MX6(this))
639                 /*
640                  * Set the default value for the gpmi clock.
641                  *
642                  * If you want to use the ONFI nand which is in the
643                  * Synchronous Mode, you should change the clock as you need.
644                  */
645                 clk_set_rate(r->clock[0], 22000000);
646 
647         return 0;
648 
649 err_clock:
650         dev_dbg(this->dev, "failed in finding the clocks.\n");
651         return err;
652 }
653 
654 static int acquire_resources(struct gpmi_nand_data *this)
655 {
656         int ret;
657 
658         ret = acquire_register_block(this, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME);
659         if (ret)
660                 goto exit_regs;
661 
662         ret = acquire_register_block(this, GPMI_NAND_BCH_REGS_ADDR_RES_NAME);
663         if (ret)
664                 goto exit_regs;
665 
666         ret = acquire_bch_irq(this, bch_irq);
667         if (ret)
668                 goto exit_regs;
669 
670         ret = acquire_dma_channels(this);
671         if (ret)
672                 goto exit_regs;
673 
674         ret = gpmi_get_clks(this);
675         if (ret)
676                 goto exit_clock;
677         return 0;
678 
679 exit_clock:
680         release_dma_channels(this);
681 exit_regs:
682         return ret;
683 }
684 
685 static void release_resources(struct gpmi_nand_data *this)
686 {
687         release_dma_channels(this);
688 }
689 
690 static int init_hardware(struct gpmi_nand_data *this)
691 {
692         int ret;
693 
694         /*
695          * This structure contains the "safe" GPMI timing that should succeed
696          * with any NAND Flash device
697          * (although, with less-than-optimal performance).
698          */
699         struct nand_timing  safe_timing = {
700                 .data_setup_in_ns        = 80,
701                 .data_hold_in_ns         = 60,
702                 .address_setup_in_ns     = 25,
703                 .gpmi_sample_delay_in_ns =  6,
704                 .tREA_in_ns              = -1,
705                 .tRLOH_in_ns             = -1,
706                 .tRHOH_in_ns             = -1,
707         };
708 
709         /* Initialize the hardwares. */
710         ret = gpmi_init(this);
711         if (ret)
712                 return ret;
713 
714         this->timing = safe_timing;
715         return 0;
716 }
717 
718 static int read_page_prepare(struct gpmi_nand_data *this,
719                         void *destination, unsigned length,
720                         void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
721                         void **use_virt, dma_addr_t *use_phys)
722 {
723         struct device *dev = this->dev;
724 
725         if (virt_addr_valid(destination)) {
726                 dma_addr_t dest_phys;
727 
728                 dest_phys = dma_map_single(dev, destination,
729                                                 length, DMA_FROM_DEVICE);
730                 if (dma_mapping_error(dev, dest_phys)) {
731                         if (alt_size < length) {
732                                 dev_err(dev, "Alternate buffer is too small\n");
733                                 return -ENOMEM;
734                         }
735                         goto map_failed;
736                 }
737                 *use_virt = destination;
738                 *use_phys = dest_phys;
739                 this->direct_dma_map_ok = true;
740                 return 0;
741         }
742 
743 map_failed:
744         *use_virt = alt_virt;
745         *use_phys = alt_phys;
746         this->direct_dma_map_ok = false;
747         return 0;
748 }
749 
750 static inline void read_page_end(struct gpmi_nand_data *this,
751                         void *destination, unsigned length,
752                         void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
753                         void *used_virt, dma_addr_t used_phys)
754 {
755         if (this->direct_dma_map_ok)
756                 dma_unmap_single(this->dev, used_phys, length, DMA_FROM_DEVICE);
757 }
758 
759 static inline void read_page_swap_end(struct gpmi_nand_data *this,
760                         void *destination, unsigned length,
761                         void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
762                         void *used_virt, dma_addr_t used_phys)
763 {
764         if (!this->direct_dma_map_ok)
765                 memcpy(destination, alt_virt, length);
766 }
767 
768 static int send_page_prepare(struct gpmi_nand_data *this,
769                         const void *source, unsigned length,
770                         void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
771                         const void **use_virt, dma_addr_t *use_phys)
772 {
773         struct device *dev = this->dev;
774 
775         if (virt_addr_valid(source)) {
776                 dma_addr_t source_phys;
777 
778                 source_phys = dma_map_single(dev, (void *)source, length,
779                                                 DMA_TO_DEVICE);
780                 if (dma_mapping_error(dev, source_phys)) {
781                         if (alt_size < length) {
782                                 dev_err(dev, "Alternate buffer is too small\n");
783                                 return -ENOMEM;
784                         }
785                         goto map_failed;
786                 }
787                 *use_virt = source;
788                 *use_phys = source_phys;
789                 return 0;
790         }
791 map_failed:
792         /*
793          * Copy the content of the source buffer into the alternate
794          * buffer and set up the return values accordingly.
795          */
796         memcpy(alt_virt, source, length);
797 
798         *use_virt = alt_virt;
799         *use_phys = alt_phys;
800         return 0;
801 }
802 
803 static void send_page_end(struct gpmi_nand_data *this,
804                         const void *source, unsigned length,
805                         void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
806                         const void *used_virt, dma_addr_t used_phys)
807 {
808         struct device *dev = this->dev;
809         if (used_virt == source)
810                 dma_unmap_single(dev, used_phys, length, DMA_TO_DEVICE);
811 }
812 
813 static void gpmi_free_dma_buffer(struct gpmi_nand_data *this)
814 {
815         struct device *dev = this->dev;
816 
817         if (this->page_buffer_virt && virt_addr_valid(this->page_buffer_virt))
818                 dma_free_coherent(dev, this->page_buffer_size,
819                                         this->page_buffer_virt,
820                                         this->page_buffer_phys);
821         kfree(this->cmd_buffer);
822         kfree(this->data_buffer_dma);
823         kfree(this->raw_buffer);
824 
825         this->cmd_buffer        = NULL;
826         this->data_buffer_dma   = NULL;
827         this->raw_buffer        = NULL;
828         this->page_buffer_virt  = NULL;
829         this->page_buffer_size  =  0;
830 }
831 
832 /* Allocate the DMA buffers */
833 static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this)
834 {
835         struct bch_geometry *geo = &this->bch_geometry;
836         struct device *dev = this->dev;
837         struct mtd_info *mtd = nand_to_mtd(&this->nand);
838 
839         /* [1] Allocate a command buffer. PAGE_SIZE is enough. */
840         this->cmd_buffer = kzalloc(PAGE_SIZE, GFP_DMA | GFP_KERNEL);
841         if (this->cmd_buffer == NULL)
842                 goto error_alloc;
843 
844         /*
845          * [2] Allocate a read/write data buffer.
846          *     The gpmi_alloc_dma_buffer can be called twice.
847          *     We allocate a PAGE_SIZE length buffer if gpmi_alloc_dma_buffer
848          *     is called before the nand_scan_ident; and we allocate a buffer
849          *     of the real NAND page size when the gpmi_alloc_dma_buffer is
850          *     called after the nand_scan_ident.
851          */
852         this->data_buffer_dma = kzalloc(mtd->writesize ?: PAGE_SIZE,
853                                         GFP_DMA | GFP_KERNEL);
854         if (this->data_buffer_dma == NULL)
855                 goto error_alloc;
856 
857         /*
858          * [3] Allocate the page buffer.
859          *
860          * Both the payload buffer and the auxiliary buffer must appear on
861          * 32-bit boundaries. We presume the size of the payload buffer is a
862          * power of two and is much larger than four, which guarantees the
863          * auxiliary buffer will appear on a 32-bit boundary.
864          */
865         this->page_buffer_size = geo->payload_size + geo->auxiliary_size;
866         this->page_buffer_virt = dma_alloc_coherent(dev, this->page_buffer_size,
867                                         &this->page_buffer_phys, GFP_DMA);
868         if (!this->page_buffer_virt)
869                 goto error_alloc;
870 
871         this->raw_buffer = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
872         if (!this->raw_buffer)
873                 goto error_alloc;
874 
875         /* Slice up the page buffer. */
876         this->payload_virt = this->page_buffer_virt;
877         this->payload_phys = this->page_buffer_phys;
878         this->auxiliary_virt = this->payload_virt + geo->payload_size;
879         this->auxiliary_phys = this->payload_phys + geo->payload_size;
880         return 0;
881 
882 error_alloc:
883         gpmi_free_dma_buffer(this);
884         return -ENOMEM;
885 }
886 
887 static void gpmi_cmd_ctrl(struct mtd_info *mtd, int data, unsigned int ctrl)
888 {
889         struct nand_chip *chip = mtd_to_nand(mtd);
890         struct gpmi_nand_data *this = nand_get_controller_data(chip);
891         int ret;
892 
893         /*
894          * Every operation begins with a command byte and a series of zero or
895          * more address bytes. These are distinguished by either the Address
896          * Latch Enable (ALE) or Command Latch Enable (CLE) signals being
897          * asserted. When MTD is ready to execute the command, it will deassert
898          * both latch enables.
899          *
900          * Rather than run a separate DMA operation for every single byte, we
901          * queue them up and run a single DMA operation for the entire series
902          * of command and data bytes. NAND_CMD_NONE means the END of the queue.
903          */
904         if ((ctrl & (NAND_ALE | NAND_CLE))) {
905                 if (data != NAND_CMD_NONE)
906                         this->cmd_buffer[this->command_length++] = data;
907                 return;
908         }
909 
910         if (!this->command_length)
911                 return;
912 
913         ret = gpmi_send_command(this);
914         if (ret)
915                 dev_err(this->dev, "Chip: %u, Error %d\n",
916                         this->current_chip, ret);
917 
918         this->command_length = 0;
919 }
920 
921 static int gpmi_dev_ready(struct mtd_info *mtd)
922 {
923         struct nand_chip *chip = mtd_to_nand(mtd);
924         struct gpmi_nand_data *this = nand_get_controller_data(chip);
925 
926         return gpmi_is_ready(this, this->current_chip);
927 }
928 
929 static void gpmi_select_chip(struct mtd_info *mtd, int chipnr)
930 {
931         struct nand_chip *chip = mtd_to_nand(mtd);
932         struct gpmi_nand_data *this = nand_get_controller_data(chip);
933 
934         if ((this->current_chip < 0) && (chipnr >= 0))
935                 gpmi_begin(this);
936         else if ((this->current_chip >= 0) && (chipnr < 0))
937                 gpmi_end(this);
938 
939         this->current_chip = chipnr;
940 }
941 
942 static void gpmi_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
943 {
944         struct nand_chip *chip = mtd_to_nand(mtd);
945         struct gpmi_nand_data *this = nand_get_controller_data(chip);
946 
947         dev_dbg(this->dev, "len is %d\n", len);
948         this->upper_buf = buf;
949         this->upper_len = len;
950 
951         gpmi_read_data(this);
952 }
953 
954 static void gpmi_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
955 {
956         struct nand_chip *chip = mtd_to_nand(mtd);
957         struct gpmi_nand_data *this = nand_get_controller_data(chip);
958 
959         dev_dbg(this->dev, "len is %d\n", len);
960         this->upper_buf = (uint8_t *)buf;
961         this->upper_len = len;
962 
963         gpmi_send_data(this);
964 }
965 
966 static uint8_t gpmi_read_byte(struct mtd_info *mtd)
967 {
968         struct nand_chip *chip = mtd_to_nand(mtd);
969         struct gpmi_nand_data *this = nand_get_controller_data(chip);
970         uint8_t *buf = this->data_buffer_dma;
971 
972         gpmi_read_buf(mtd, buf, 1);
973         return buf[0];
974 }
975 
976 /*
977  * Handles block mark swapping.
978  * It can be called in swapping the block mark, or swapping it back,
979  * because the the operations are the same.
980  */
981 static void block_mark_swapping(struct gpmi_nand_data *this,
982                                 void *payload, void *auxiliary)
983 {
984         struct bch_geometry *nfc_geo = &this->bch_geometry;
985         unsigned char *p;
986         unsigned char *a;
987         unsigned int  bit;
988         unsigned char mask;
989         unsigned char from_data;
990         unsigned char from_oob;
991 
992         if (!this->swap_block_mark)
993                 return;
994 
995         /*
996          * If control arrives here, we're swapping. Make some convenience
997          * variables.
998          */
999         bit = nfc_geo->block_mark_bit_offset;
1000         p   = payload + nfc_geo->block_mark_byte_offset;
1001         a   = auxiliary;
1002 
1003         /*
1004          * Get the byte from the data area that overlays the block mark. Since
1005          * the ECC engine applies its own view to the bits in the page, the
1006          * physical block mark won't (in general) appear on a byte boundary in
1007          * the data.
1008          */
1009         from_data = (p[0] >> bit) | (p[1] << (8 - bit));
1010 
1011         /* Get the byte from the OOB. */
1012         from_oob = a[0];
1013 
1014         /* Swap them. */
1015         a[0] = from_data;
1016 
1017         mask = (0x1 << bit) - 1;
1018         p[0] = (p[0] & mask) | (from_oob << bit);
1019 
1020         mask = ~0 << bit;
1021         p[1] = (p[1] & mask) | (from_oob >> (8 - bit));
1022 }
1023 
1024 static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
1025                                 uint8_t *buf, int oob_required, int page)
1026 {
1027         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1028         struct bch_geometry *nfc_geo = &this->bch_geometry;
1029         void          *payload_virt;
1030         dma_addr_t    payload_phys;
1031         void          *auxiliary_virt;
1032         dma_addr_t    auxiliary_phys;
1033         unsigned int  i;
1034         unsigned char *status;
1035         unsigned int  max_bitflips = 0;
1036         int           ret;
1037 
1038         dev_dbg(this->dev, "page number is : %d\n", page);
1039         ret = read_page_prepare(this, buf, nfc_geo->payload_size,
1040                                         this->payload_virt, this->payload_phys,
1041                                         nfc_geo->payload_size,
1042                                         &payload_virt, &payload_phys);
1043         if (ret) {
1044                 dev_err(this->dev, "Inadequate DMA buffer\n");
1045                 ret = -ENOMEM;
1046                 return ret;
1047         }
1048         auxiliary_virt = this->auxiliary_virt;
1049         auxiliary_phys = this->auxiliary_phys;
1050 
1051         /* go! */
1052         ret = gpmi_read_page(this, payload_phys, auxiliary_phys);
1053         read_page_end(this, buf, nfc_geo->payload_size,
1054                         this->payload_virt, this->payload_phys,
1055                         nfc_geo->payload_size,
1056                         payload_virt, payload_phys);
1057         if (ret) {
1058                 dev_err(this->dev, "Error in ECC-based read: %d\n", ret);
1059                 return ret;
1060         }
1061 
1062         /* handle the block mark swapping */
1063         block_mark_swapping(this, payload_virt, auxiliary_virt);
1064 
1065         /* Loop over status bytes, accumulating ECC status. */
1066         status = auxiliary_virt + nfc_geo->auxiliary_status_offset;
1067 
1068         read_page_swap_end(this, buf, nfc_geo->payload_size,
1069                            this->payload_virt, this->payload_phys,
1070                            nfc_geo->payload_size,
1071                            payload_virt, payload_phys);
1072 
1073         for (i = 0; i < nfc_geo->ecc_chunk_count; i++, status++) {
1074                 if ((*status == STATUS_GOOD) || (*status == STATUS_ERASED))
1075                         continue;
1076 
1077                 if (*status == STATUS_UNCORRECTABLE) {
1078                         int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
1079                         u8 *eccbuf = this->raw_buffer;
1080                         int offset, bitoffset;
1081                         int eccbytes;
1082                         int flips;
1083 
1084                         /* Read ECC bytes into our internal raw_buffer */
1085                         offset = nfc_geo->metadata_size * 8;
1086                         offset += ((8 * nfc_geo->ecc_chunk_size) + eccbits) * (i + 1);
1087                         offset -= eccbits;
1088                         bitoffset = offset % 8;
1089                         eccbytes = DIV_ROUND_UP(offset + eccbits, 8);
1090                         offset /= 8;
1091                         eccbytes -= offset;
1092                         chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
1093                         chip->read_buf(mtd, eccbuf, eccbytes);
1094 
1095                         /*
1096                          * ECC data are not byte aligned and we may have
1097                          * in-band data in the first and last byte of
1098                          * eccbuf. Set non-eccbits to one so that
1099                          * nand_check_erased_ecc_chunk() does not count them
1100                          * as bitflips.
1101                          */
1102                         if (bitoffset)
1103                                 eccbuf[0] |= GENMASK(bitoffset - 1, 0);
1104 
1105                         bitoffset = (bitoffset + eccbits) % 8;
1106                         if (bitoffset)
1107                                 eccbuf[eccbytes - 1] |= GENMASK(7, bitoffset);
1108 
1109                         /*
1110                          * The ECC hardware has an uncorrectable ECC status
1111                          * code in case we have bitflips in an erased page. As
1112                          * nothing was written into this subpage the ECC is
1113                          * obviously wrong and we can not trust it. We assume
1114                          * at this point that we are reading an erased page and
1115                          * try to correct the bitflips in buffer up to
1116                          * ecc_strength bitflips. If this is a page with random
1117                          * data, we exceed this number of bitflips and have a
1118                          * ECC failure. Otherwise we use the corrected buffer.
1119                          */
1120                         if (i == 0) {
1121                                 /* The first block includes metadata */
1122                                 flips = nand_check_erased_ecc_chunk(
1123                                                 buf + i * nfc_geo->ecc_chunk_size,
1124                                                 nfc_geo->ecc_chunk_size,
1125                                                 eccbuf, eccbytes,
1126                                                 auxiliary_virt,
1127                                                 nfc_geo->metadata_size,
1128                                                 nfc_geo->ecc_strength);
1129                         } else {
1130                                 flips = nand_check_erased_ecc_chunk(
1131                                                 buf + i * nfc_geo->ecc_chunk_size,
1132                                                 nfc_geo->ecc_chunk_size,
1133                                                 eccbuf, eccbytes,
1134                                                 NULL, 0,
1135                                                 nfc_geo->ecc_strength);
1136                         }
1137 
1138                         if (flips > 0) {
1139                                 max_bitflips = max_t(unsigned int, max_bitflips,
1140                                                      flips);
1141                                 mtd->ecc_stats.corrected += flips;
1142                                 continue;
1143                         }
1144 
1145                         mtd->ecc_stats.failed++;
1146                         continue;
1147                 }
1148 
1149                 mtd->ecc_stats.corrected += *status;
1150                 max_bitflips = max_t(unsigned int, max_bitflips, *status);
1151         }
1152 
1153         if (oob_required) {
1154                 /*
1155                  * It's time to deliver the OOB bytes. See gpmi_ecc_read_oob()
1156                  * for details about our policy for delivering the OOB.
1157                  *
1158                  * We fill the caller's buffer with set bits, and then copy the
1159                  * block mark to th caller's buffer. Note that, if block mark
1160                  * swapping was necessary, it has already been done, so we can
1161                  * rely on the first byte of the auxiliary buffer to contain
1162                  * the block mark.
1163                  */
1164                 memset(chip->oob_poi, ~0, mtd->oobsize);
1165                 chip->oob_poi[0] = ((uint8_t *) auxiliary_virt)[0];
1166         }
1167 
1168         return max_bitflips;
1169 }
1170 
1171 /* Fake a virtual small page for the subpage read */
1172 static int gpmi_ecc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1173                         uint32_t offs, uint32_t len, uint8_t *buf, int page)
1174 {
1175         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1176         void __iomem *bch_regs = this->resources.bch_regs;
1177         struct bch_geometry old_geo = this->bch_geometry;
1178         struct bch_geometry *geo = &this->bch_geometry;
1179         int size = chip->ecc.size; /* ECC chunk size */
1180         int meta, n, page_size;
1181         u32 r1_old, r2_old, r1_new, r2_new;
1182         unsigned int max_bitflips;
1183         int first, last, marker_pos;
1184         int ecc_parity_size;
1185         int col = 0;
1186         int old_swap_block_mark = this->swap_block_mark;
1187 
1188         /* The size of ECC parity */
1189         ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
1190 
1191         /* Align it with the chunk size */
1192         first = offs / size;
1193         last = (offs + len - 1) / size;
1194 
1195         if (this->swap_block_mark) {
1196                 /*
1197                  * Find the chunk which contains the Block Marker.
1198                  * If this chunk is in the range of [first, last],
1199                  * we have to read out the whole page.
1200                  * Why? since we had swapped the data at the position of Block
1201                  * Marker to the metadata which is bound with the chunk 0.
1202                  */
1203                 marker_pos = geo->block_mark_byte_offset / size;
1204                 if (last >= marker_pos && first <= marker_pos) {
1205                         dev_dbg(this->dev,
1206                                 "page:%d, first:%d, last:%d, marker at:%d\n",
1207                                 page, first, last, marker_pos);
1208                         return gpmi_ecc_read_page(mtd, chip, buf, 0, page);
1209                 }
1210         }
1211 
1212         meta = geo->metadata_size;
1213         if (first) {
1214                 col = meta + (size + ecc_parity_size) * first;
1215                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, col, -1);
1216 
1217                 meta = 0;
1218                 buf = buf + first * size;
1219         }
1220 
1221         /* Save the old environment */
1222         r1_old = r1_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT0);
1223         r2_old = r2_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT1);
1224 
1225         /* change the BCH registers and bch_geometry{} */
1226         n = last - first + 1;
1227         page_size = meta + (size + ecc_parity_size) * n;
1228 
1229         r1_new &= ~(BM_BCH_FLASH0LAYOUT0_NBLOCKS |
1230                         BM_BCH_FLASH0LAYOUT0_META_SIZE);
1231         r1_new |= BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1)
1232                         | BF_BCH_FLASH0LAYOUT0_META_SIZE(meta);
1233         writel(r1_new, bch_regs + HW_BCH_FLASH0LAYOUT0);
1234 
1235         r2_new &= ~BM_BCH_FLASH0LAYOUT1_PAGE_SIZE;
1236         r2_new |= BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size);
1237         writel(r2_new, bch_regs + HW_BCH_FLASH0LAYOUT1);
1238 
1239         geo->ecc_chunk_count = n;
1240         geo->payload_size = n * size;
1241         geo->page_size = page_size;
1242         geo->auxiliary_status_offset = ALIGN(meta, 4);
1243 
1244         dev_dbg(this->dev, "page:%d(%d:%d)%d, chunk:(%d:%d), BCH PG size:%d\n",
1245                 page, offs, len, col, first, n, page_size);
1246 
1247         /* Read the subpage now */
1248         this->swap_block_mark = false;
1249         max_bitflips = gpmi_ecc_read_page(mtd, chip, buf, 0, page);
1250 
1251         /* Restore */
1252         writel(r1_old, bch_regs + HW_BCH_FLASH0LAYOUT0);
1253         writel(r2_old, bch_regs + HW_BCH_FLASH0LAYOUT1);
1254         this->bch_geometry = old_geo;
1255         this->swap_block_mark = old_swap_block_mark;
1256 
1257         return max_bitflips;
1258 }
1259 
1260 static int gpmi_ecc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
1261                                 const uint8_t *buf, int oob_required, int page)
1262 {
1263         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1264         struct bch_geometry *nfc_geo = &this->bch_geometry;
1265         const void *payload_virt;
1266         dma_addr_t payload_phys;
1267         const void *auxiliary_virt;
1268         dma_addr_t auxiliary_phys;
1269         int        ret;
1270 
1271         dev_dbg(this->dev, "ecc write page.\n");
1272         if (this->swap_block_mark) {
1273                 /*
1274                  * If control arrives here, we're doing block mark swapping.
1275                  * Since we can't modify the caller's buffers, we must copy them
1276                  * into our own.
1277                  */
1278                 memcpy(this->payload_virt, buf, mtd->writesize);
1279                 payload_virt = this->payload_virt;
1280                 payload_phys = this->payload_phys;
1281 
1282                 memcpy(this->auxiliary_virt, chip->oob_poi,
1283                                 nfc_geo->auxiliary_size);
1284                 auxiliary_virt = this->auxiliary_virt;
1285                 auxiliary_phys = this->auxiliary_phys;
1286 
1287                 /* Handle block mark swapping. */
1288                 block_mark_swapping(this,
1289                                 (void *)payload_virt, (void *)auxiliary_virt);
1290         } else {
1291                 /*
1292                  * If control arrives here, we're not doing block mark swapping,
1293                  * so we can to try and use the caller's buffers.
1294                  */
1295                 ret = send_page_prepare(this,
1296                                 buf, mtd->writesize,
1297                                 this->payload_virt, this->payload_phys,
1298                                 nfc_geo->payload_size,
1299                                 &payload_virt, &payload_phys);
1300                 if (ret) {
1301                         dev_err(this->dev, "Inadequate payload DMA buffer\n");
1302                         return 0;
1303                 }
1304 
1305                 ret = send_page_prepare(this,
1306                                 chip->oob_poi, mtd->oobsize,
1307                                 this->auxiliary_virt, this->auxiliary_phys,
1308                                 nfc_geo->auxiliary_size,
1309                                 &auxiliary_virt, &auxiliary_phys);
1310                 if (ret) {
1311                         dev_err(this->dev, "Inadequate auxiliary DMA buffer\n");
1312                         goto exit_auxiliary;
1313                 }
1314         }
1315 
1316         /* Ask the NFC. */
1317         ret = gpmi_send_page(this, payload_phys, auxiliary_phys);
1318         if (ret)
1319                 dev_err(this->dev, "Error in ECC-based write: %d\n", ret);
1320 
1321         if (!this->swap_block_mark) {
1322                 send_page_end(this, chip->oob_poi, mtd->oobsize,
1323                                 this->auxiliary_virt, this->auxiliary_phys,
1324                                 nfc_geo->auxiliary_size,
1325                                 auxiliary_virt, auxiliary_phys);
1326 exit_auxiliary:
1327                 send_page_end(this, buf, mtd->writesize,
1328                                 this->payload_virt, this->payload_phys,
1329                                 nfc_geo->payload_size,
1330                                 payload_virt, payload_phys);
1331         }
1332 
1333         return 0;
1334 }
1335 
1336 /*
1337  * There are several places in this driver where we have to handle the OOB and
1338  * block marks. This is the function where things are the most complicated, so
1339  * this is where we try to explain it all. All the other places refer back to
1340  * here.
1341  *
1342  * These are the rules, in order of decreasing importance:
1343  *
1344  * 1) Nothing the caller does can be allowed to imperil the block mark.
1345  *
1346  * 2) In read operations, the first byte of the OOB we return must reflect the
1347  *    true state of the block mark, no matter where that block mark appears in
1348  *    the physical page.
1349  *
1350  * 3) ECC-based read operations return an OOB full of set bits (since we never
1351  *    allow ECC-based writes to the OOB, it doesn't matter what ECC-based reads
1352  *    return).
1353  *
1354  * 4) "Raw" read operations return a direct view of the physical bytes in the
1355  *    page, using the conventional definition of which bytes are data and which
1356  *    are OOB. This gives the caller a way to see the actual, physical bytes
1357  *    in the page, without the distortions applied by our ECC engine.
1358  *
1359  *
1360  * What we do for this specific read operation depends on two questions:
1361  *
1362  * 1) Are we doing a "raw" read, or an ECC-based read?
1363  *
1364  * 2) Are we using block mark swapping or transcription?
1365  *
1366  * There are four cases, illustrated by the following Karnaugh map:
1367  *
1368  *                    |           Raw           |         ECC-based       |
1369  *       -------------+-------------------------+-------------------------+
1370  *                    | Read the conventional   |                         |
1371  *                    | OOB at the end of the   |                         |
1372  *       Swapping     | page and return it. It  |                         |
1373  *                    | contains exactly what   |                         |
1374  *                    | we want.                | Read the block mark and |
1375  *       -------------+-------------------------+ return it in a buffer   |
1376  *                    | Read the conventional   | full of set bits.       |
1377  *                    | OOB at the end of the   |                         |
1378  *                    | page and also the block |                         |
1379  *       Transcribing | mark in the metadata.   |                         |
1380  *                    | Copy the block mark     |                         |
1381  *                    | into the first byte of  |                         |
1382  *                    | the OOB.                |                         |
1383  *       -------------+-------------------------+-------------------------+
1384  *
1385  * Note that we break rule #4 in the Transcribing/Raw case because we're not
1386  * giving an accurate view of the actual, physical bytes in the page (we're
1387  * overwriting the block mark). That's OK because it's more important to follow
1388  * rule #2.
1389  *
1390  * It turns out that knowing whether we want an "ECC-based" or "raw" read is not
1391  * easy. When reading a page, for example, the NAND Flash MTD code calls our
1392  * ecc.read_page or ecc.read_page_raw function. Thus, the fact that MTD wants an
1393  * ECC-based or raw view of the page is implicit in which function it calls
1394  * (there is a similar pair of ECC-based/raw functions for writing).
1395  */
1396 static int gpmi_ecc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
1397                                 int page)
1398 {
1399         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1400 
1401         dev_dbg(this->dev, "page number is %d\n", page);
1402         /* clear the OOB buffer */
1403         memset(chip->oob_poi, ~0, mtd->oobsize);
1404 
1405         /* Read out the conventional OOB. */
1406         chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
1407         chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1408 
1409         /*
1410          * Now, we want to make sure the block mark is correct. In the
1411          * non-transcribing case (!GPMI_IS_MX23()), we already have it.
1412          * Otherwise, we need to explicitly read it.
1413          */
1414         if (GPMI_IS_MX23(this)) {
1415                 /* Read the block mark into the first byte of the OOB buffer. */
1416                 chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1417                 chip->oob_poi[0] = chip->read_byte(mtd);
1418         }
1419 
1420         return 0;
1421 }
1422 
1423 static int
1424 gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page)
1425 {
1426         struct mtd_oob_region of = { };
1427         int status = 0;
1428 
1429         /* Do we have available oob area? */
1430         mtd_ooblayout_free(mtd, 0, &of);
1431         if (!of.length)
1432                 return -EPERM;
1433 
1434         if (!nand_is_slc(chip))
1435                 return -EPERM;
1436 
1437         chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize + of.offset, page);
1438         chip->write_buf(mtd, chip->oob_poi + of.offset, of.length);
1439         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1440 
1441         status = chip->waitfunc(mtd, chip);
1442         return status & NAND_STATUS_FAIL ? -EIO : 0;
1443 }
1444 
1445 /*
1446  * This function reads a NAND page without involving the ECC engine (no HW
1447  * ECC correction).
1448  * The tricky part in the GPMI/BCH controller is that it stores ECC bits
1449  * inline (interleaved with payload DATA), and do not align data chunk on
1450  * byte boundaries.
1451  * We thus need to take care moving the payload data and ECC bits stored in the
1452  * page into the provided buffers, which is why we're using gpmi_copy_bits.
1453  *
1454  * See set_geometry_by_ecc_info inline comments to have a full description
1455  * of the layout used by the GPMI controller.
1456  */
1457 static int gpmi_ecc_read_page_raw(struct mtd_info *mtd,
1458                                   struct nand_chip *chip, uint8_t *buf,
1459                                   int oob_required, int page)
1460 {
1461         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1462         struct bch_geometry *nfc_geo = &this->bch_geometry;
1463         int eccsize = nfc_geo->ecc_chunk_size;
1464         int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
1465         u8 *tmp_buf = this->raw_buffer;
1466         size_t src_bit_off;
1467         size_t oob_bit_off;
1468         size_t oob_byte_off;
1469         uint8_t *oob = chip->oob_poi;
1470         int step;
1471 
1472         chip->read_buf(mtd, tmp_buf,
1473                        mtd->writesize + mtd->oobsize);
1474 
1475         /*
1476          * If required, swap the bad block marker and the data stored in the
1477          * metadata section, so that we don't wrongly consider a block as bad.
1478          *
1479          * See the layout description for a detailed explanation on why this
1480          * is needed.
1481          */
1482         if (this->swap_block_mark) {
1483                 u8 swap = tmp_buf[0];
1484 
1485                 tmp_buf[0] = tmp_buf[mtd->writesize];
1486                 tmp_buf[mtd->writesize] = swap;
1487         }
1488 
1489         /*
1490          * Copy the metadata section into the oob buffer (this section is
1491          * guaranteed to be aligned on a byte boundary).
1492          */
1493         if (oob_required)
1494                 memcpy(oob, tmp_buf, nfc_geo->metadata_size);
1495 
1496         oob_bit_off = nfc_geo->metadata_size * 8;
1497         src_bit_off = oob_bit_off;
1498 
1499         /* Extract interleaved payload data and ECC bits */
1500         for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
1501                 if (buf)
1502                         gpmi_copy_bits(buf, step * eccsize * 8,
1503                                        tmp_buf, src_bit_off,
1504                                        eccsize * 8);
1505                 src_bit_off += eccsize * 8;
1506 
1507                 /* Align last ECC block to align a byte boundary */
1508                 if (step == nfc_geo->ecc_chunk_count - 1 &&
1509                     (oob_bit_off + eccbits) % 8)
1510                         eccbits += 8 - ((oob_bit_off + eccbits) % 8);
1511 
1512                 if (oob_required)
1513                         gpmi_copy_bits(oob, oob_bit_off,
1514                                        tmp_buf, src_bit_off,
1515                                        eccbits);
1516 
1517                 src_bit_off += eccbits;
1518                 oob_bit_off += eccbits;
1519         }
1520 
1521         if (oob_required) {
1522                 oob_byte_off = oob_bit_off / 8;
1523 
1524                 if (oob_byte_off < mtd->oobsize)
1525                         memcpy(oob + oob_byte_off,
1526                                tmp_buf + mtd->writesize + oob_byte_off,
1527                                mtd->oobsize - oob_byte_off);
1528         }
1529 
1530         return 0;
1531 }
1532 
1533 /*
1534  * This function writes a NAND page without involving the ECC engine (no HW
1535  * ECC generation).
1536  * The tricky part in the GPMI/BCH controller is that it stores ECC bits
1537  * inline (interleaved with payload DATA), and do not align data chunk on
1538  * byte boundaries.
1539  * We thus need to take care moving the OOB area at the right place in the
1540  * final page, which is why we're using gpmi_copy_bits.
1541  *
1542  * See set_geometry_by_ecc_info inline comments to have a full description
1543  * of the layout used by the GPMI controller.
1544  */
1545 static int gpmi_ecc_write_page_raw(struct mtd_info *mtd,
1546                                    struct nand_chip *chip,
1547                                    const uint8_t *buf,
1548                                    int oob_required, int page)
1549 {
1550         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1551         struct bch_geometry *nfc_geo = &this->bch_geometry;
1552         int eccsize = nfc_geo->ecc_chunk_size;
1553         int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
1554         u8 *tmp_buf = this->raw_buffer;
1555         uint8_t *oob = chip->oob_poi;
1556         size_t dst_bit_off;
1557         size_t oob_bit_off;
1558         size_t oob_byte_off;
1559         int step;
1560 
1561         /*
1562          * Initialize all bits to 1 in case we don't have a buffer for the
1563          * payload or oob data in order to leave unspecified bits of data
1564          * to their initial state.
1565          */
1566         if (!buf || !oob_required)
1567                 memset(tmp_buf, 0xff, mtd->writesize + mtd->oobsize);
1568 
1569         /*
1570          * First copy the metadata section (stored in oob buffer) at the
1571          * beginning of the page, as imposed by the GPMI layout.
1572          */
1573         memcpy(tmp_buf, oob, nfc_geo->metadata_size);
1574         oob_bit_off = nfc_geo->metadata_size * 8;
1575         dst_bit_off = oob_bit_off;
1576 
1577         /* Interleave payload data and ECC bits */
1578         for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
1579                 if (buf)
1580                         gpmi_copy_bits(tmp_buf, dst_bit_off,
1581                                        buf, step * eccsize * 8, eccsize * 8);
1582                 dst_bit_off += eccsize * 8;
1583 
1584                 /* Align last ECC block to align a byte boundary */
1585                 if (step == nfc_geo->ecc_chunk_count - 1 &&
1586                     (oob_bit_off + eccbits) % 8)
1587                         eccbits += 8 - ((oob_bit_off + eccbits) % 8);
1588 
1589                 if (oob_required)
1590                         gpmi_copy_bits(tmp_buf, dst_bit_off,
1591                                        oob, oob_bit_off, eccbits);
1592 
1593                 dst_bit_off += eccbits;
1594                 oob_bit_off += eccbits;
1595         }
1596 
1597         oob_byte_off = oob_bit_off / 8;
1598 
1599         if (oob_required && oob_byte_off < mtd->oobsize)
1600                 memcpy(tmp_buf + mtd->writesize + oob_byte_off,
1601                        oob + oob_byte_off, mtd->oobsize - oob_byte_off);
1602 
1603         /*
1604          * If required, swap the bad block marker and the first byte of the
1605          * metadata section, so that we don't modify the bad block marker.
1606          *
1607          * See the layout description for a detailed explanation on why this
1608          * is needed.
1609          */
1610         if (this->swap_block_mark) {
1611                 u8 swap = tmp_buf[0];
1612 
1613                 tmp_buf[0] = tmp_buf[mtd->writesize];
1614                 tmp_buf[mtd->writesize] = swap;
1615         }
1616 
1617         chip->write_buf(mtd, tmp_buf, mtd->writesize + mtd->oobsize);
1618 
1619         return 0;
1620 }
1621 
1622 static int gpmi_ecc_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
1623                                  int page)
1624 {
1625         chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1626 
1627         return gpmi_ecc_read_page_raw(mtd, chip, NULL, 1, page);
1628 }
1629 
1630 static int gpmi_ecc_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
1631                                  int page)
1632 {
1633         chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0, page);
1634 
1635         return gpmi_ecc_write_page_raw(mtd, chip, NULL, 1, page);
1636 }
1637 
1638 static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs)
1639 {
1640         struct nand_chip *chip = mtd_to_nand(mtd);
1641         struct gpmi_nand_data *this = nand_get_controller_data(chip);
1642         int ret = 0;
1643         uint8_t *block_mark;
1644         int column, page, status, chipnr;
1645 
1646         chipnr = (int)(ofs >> chip->chip_shift);
1647         chip->select_chip(mtd, chipnr);
1648 
1649         column = !GPMI_IS_MX23(this) ? mtd->writesize : 0;
1650 
1651         /* Write the block mark. */
1652         block_mark = this->data_buffer_dma;
1653         block_mark[0] = 0; /* bad block marker */
1654 
1655         /* Shift to get page */
1656         page = (int)(ofs >> chip->page_shift);
1657 
1658         chip->cmdfunc(mtd, NAND_CMD_SEQIN, column, page);
1659         chip->write_buf(mtd, block_mark, 1);
1660         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1661 
1662         status = chip->waitfunc(mtd, chip);
1663         if (status & NAND_STATUS_FAIL)
1664                 ret = -EIO;
1665 
1666         chip->select_chip(mtd, -1);
1667 
1668         return ret;
1669 }
1670 
1671 static int nand_boot_set_geometry(struct gpmi_nand_data *this)
1672 {
1673         struct boot_rom_geometry *geometry = &this->rom_geometry;
1674 
1675         /*
1676          * Set the boot block stride size.
1677          *
1678          * In principle, we should be reading this from the OTP bits, since
1679          * that's where the ROM is going to get it. In fact, we don't have any
1680          * way to read the OTP bits, so we go with the default and hope for the
1681          * best.
1682          */
1683         geometry->stride_size_in_pages = 64;
1684 
1685         /*
1686          * Set the search area stride exponent.
1687          *
1688          * In principle, we should be reading this from the OTP bits, since
1689          * that's where the ROM is going to get it. In fact, we don't have any
1690          * way to read the OTP bits, so we go with the default and hope for the
1691          * best.
1692          */
1693         geometry->search_area_stride_exponent = 2;
1694         return 0;
1695 }
1696 
1697 static const char  *fingerprint = "STMP";
1698 static int mx23_check_transcription_stamp(struct gpmi_nand_data *this)
1699 {
1700         struct boot_rom_geometry *rom_geo = &this->rom_geometry;
1701         struct device *dev = this->dev;
1702         struct nand_chip *chip = &this->nand;
1703         struct mtd_info *mtd = nand_to_mtd(chip);
1704         unsigned int search_area_size_in_strides;
1705         unsigned int stride;
1706         unsigned int page;
1707         uint8_t *buffer = chip->buffers->databuf;
1708         int saved_chip_number;
1709         int found_an_ncb_fingerprint = false;
1710 
1711         /* Compute the number of strides in a search area. */
1712         search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
1713 
1714         saved_chip_number = this->current_chip;
1715         chip->select_chip(mtd, 0);
1716 
1717         /*
1718          * Loop through the first search area, looking for the NCB fingerprint.
1719          */
1720         dev_dbg(dev, "Scanning for an NCB fingerprint...\n");
1721 
1722         for (stride = 0; stride < search_area_size_in_strides; stride++) {
1723                 /* Compute the page addresses. */
1724                 page = stride * rom_geo->stride_size_in_pages;
1725 
1726                 dev_dbg(dev, "Looking for a fingerprint in page 0x%x\n", page);
1727 
1728                 /*
1729                  * Read the NCB fingerprint. The fingerprint is four bytes long
1730                  * and starts in the 12th byte of the page.
1731                  */
1732                 chip->cmdfunc(mtd, NAND_CMD_READ0, 12, page);
1733                 chip->read_buf(mtd, buffer, strlen(fingerprint));
1734 
1735                 /* Look for the fingerprint. */
1736                 if (!memcmp(buffer, fingerprint, strlen(fingerprint))) {
1737                         found_an_ncb_fingerprint = true;
1738                         break;
1739                 }
1740 
1741         }
1742 
1743         chip->select_chip(mtd, saved_chip_number);
1744 
1745         if (found_an_ncb_fingerprint)
1746                 dev_dbg(dev, "\tFound a fingerprint\n");
1747         else
1748                 dev_dbg(dev, "\tNo fingerprint found\n");
1749         return found_an_ncb_fingerprint;
1750 }
1751 
1752 /* Writes a transcription stamp. */
1753 static int mx23_write_transcription_stamp(struct gpmi_nand_data *this)
1754 {
1755         struct device *dev = this->dev;
1756         struct boot_rom_geometry *rom_geo = &this->rom_geometry;
1757         struct nand_chip *chip = &this->nand;
1758         struct mtd_info *mtd = nand_to_mtd(chip);
1759         unsigned int block_size_in_pages;
1760         unsigned int search_area_size_in_strides;
1761         unsigned int search_area_size_in_pages;
1762         unsigned int search_area_size_in_blocks;
1763         unsigned int block;
1764         unsigned int stride;
1765         unsigned int page;
1766         uint8_t      *buffer = chip->buffers->databuf;
1767         int saved_chip_number;
1768         int status;
1769 
1770         /* Compute the search area geometry. */
1771         block_size_in_pages = mtd->erasesize / mtd->writesize;
1772         search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
1773         search_area_size_in_pages = search_area_size_in_strides *
1774                                         rom_geo->stride_size_in_pages;
1775         search_area_size_in_blocks =
1776                   (search_area_size_in_pages + (block_size_in_pages - 1)) /
1777                                     block_size_in_pages;
1778 
1779         dev_dbg(dev, "Search Area Geometry :\n");
1780         dev_dbg(dev, "\tin Blocks : %u\n", search_area_size_in_blocks);
1781         dev_dbg(dev, "\tin Strides: %u\n", search_area_size_in_strides);
1782         dev_dbg(dev, "\tin Pages  : %u\n", search_area_size_in_pages);
1783 
1784         /* Select chip 0. */
1785         saved_chip_number = this->current_chip;
1786         chip->select_chip(mtd, 0);
1787 
1788         /* Loop over blocks in the first search area, erasing them. */
1789         dev_dbg(dev, "Erasing the search area...\n");
1790 
1791         for (block = 0; block < search_area_size_in_blocks; block++) {
1792                 /* Compute the page address. */
1793                 page = block * block_size_in_pages;
1794 
1795                 /* Erase this block. */
1796                 dev_dbg(dev, "\tErasing block 0x%x\n", block);
1797                 chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
1798                 chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
1799 
1800                 /* Wait for the erase to finish. */
1801                 status = chip->waitfunc(mtd, chip);
1802                 if (status & NAND_STATUS_FAIL)
1803                         dev_err(dev, "[%s] Erase failed.\n", __func__);
1804         }
1805 
1806         /* Write the NCB fingerprint into the page buffer. */
1807         memset(buffer, ~0, mtd->writesize);
1808         memcpy(buffer + 12, fingerprint, strlen(fingerprint));
1809 
1810         /* Loop through the first search area, writing NCB fingerprints. */
1811         dev_dbg(dev, "Writing NCB fingerprints...\n");
1812         for (stride = 0; stride < search_area_size_in_strides; stride++) {
1813                 /* Compute the page addresses. */
1814                 page = stride * rom_geo->stride_size_in_pages;
1815 
1816                 /* Write the first page of the current stride. */
1817                 dev_dbg(dev, "Writing an NCB fingerprint in page 0x%x\n", page);
1818                 chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
1819                 chip->ecc.write_page_raw(mtd, chip, buffer, 0, page);
1820                 chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1821 
1822                 /* Wait for the write to finish. */
1823                 status = chip->waitfunc(mtd, chip);
1824                 if (status & NAND_STATUS_FAIL)
1825                         dev_err(dev, "[%s] Write failed.\n", __func__);
1826         }
1827 
1828         /* Deselect chip 0. */
1829         chip->select_chip(mtd, saved_chip_number);
1830         return 0;
1831 }
1832 
1833 static int mx23_boot_init(struct gpmi_nand_data  *this)
1834 {
1835         struct device *dev = this->dev;
1836         struct nand_chip *chip = &this->nand;
1837         struct mtd_info *mtd = nand_to_mtd(chip);
1838         unsigned int block_count;
1839         unsigned int block;
1840         int     chipnr;
1841         int     page;
1842         loff_t  byte;
1843         uint8_t block_mark;
1844         int     ret = 0;
1845 
1846         /*
1847          * If control arrives here, we can't use block mark swapping, which
1848          * means we're forced to use transcription. First, scan for the
1849          * transcription stamp. If we find it, then we don't have to do
1850          * anything -- the block marks are already transcribed.
1851          */
1852         if (mx23_check_transcription_stamp(this))
1853                 return 0;
1854 
1855         /*
1856          * If control arrives here, we couldn't find a transcription stamp, so
1857          * so we presume the block marks are in the conventional location.
1858          */
1859         dev_dbg(dev, "Transcribing bad block marks...\n");
1860 
1861         /* Compute the number of blocks in the entire medium. */
1862         block_count = chip->chipsize >> chip->phys_erase_shift;
1863 
1864         /*
1865          * Loop over all the blocks in the medium, transcribing block marks as
1866          * we go.
1867          */
1868         for (block = 0; block < block_count; block++) {
1869                 /*
1870                  * Compute the chip, page and byte addresses for this block's
1871                  * conventional mark.
1872                  */
1873                 chipnr = block >> (chip->chip_shift - chip->phys_erase_shift);
1874                 page = block << (chip->phys_erase_shift - chip->page_shift);
1875                 byte = block <<  chip->phys_erase_shift;
1876 
1877                 /* Send the command to read the conventional block mark. */
1878                 chip->select_chip(mtd, chipnr);
1879                 chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
1880                 block_mark = chip->read_byte(mtd);
1881                 chip->select_chip(mtd, -1);
1882 
1883                 /*
1884                  * Check if the block is marked bad. If so, we need to mark it
1885                  * again, but this time the result will be a mark in the
1886                  * location where we transcribe block marks.
1887                  */
1888                 if (block_mark != 0xff) {
1889                         dev_dbg(dev, "Transcribing mark in block %u\n", block);
1890                         ret = chip->block_markbad(mtd, byte);
1891                         if (ret)
1892                                 dev_err(dev,
1893                                         "Failed to mark block bad with ret %d\n",
1894                                         ret);
1895                 }
1896         }
1897 
1898         /* Write the stamp that indicates we've transcribed the block marks. */
1899         mx23_write_transcription_stamp(this);
1900         return 0;
1901 }
1902 
1903 static int nand_boot_init(struct gpmi_nand_data  *this)
1904 {
1905         nand_boot_set_geometry(this);
1906 
1907         /* This is ROM arch-specific initilization before the BBT scanning. */
1908         if (GPMI_IS_MX23(this))
1909                 return mx23_boot_init(this);
1910         return 0;
1911 }
1912 
1913 static int gpmi_set_geometry(struct gpmi_nand_data *this)
1914 {
1915         int ret;
1916 
1917         /* Free the temporary DMA memory for reading ID. */
1918         gpmi_free_dma_buffer(this);
1919 
1920         /* Set up the NFC geometry which is used by BCH. */
1921         ret = bch_set_geometry(this);
1922         if (ret) {
1923                 dev_err(this->dev, "Error setting BCH geometry : %d\n", ret);
1924                 return ret;
1925         }
1926 
1927         /* Alloc the new DMA buffers according to the pagesize and oobsize */
1928         return gpmi_alloc_dma_buffer(this);
1929 }
1930 
1931 static void gpmi_nand_exit(struct gpmi_nand_data *this)
1932 {
1933         nand_release(nand_to_mtd(&this->nand));
1934         gpmi_free_dma_buffer(this);
1935 }
1936 
1937 static int gpmi_init_last(struct gpmi_nand_data *this)
1938 {
1939         struct nand_chip *chip = &this->nand;
1940         struct mtd_info *mtd = nand_to_mtd(chip);
1941         struct nand_ecc_ctrl *ecc = &chip->ecc;
1942         struct bch_geometry *bch_geo = &this->bch_geometry;
1943         int ret;
1944 
1945         /* Set up the medium geometry */
1946         ret = gpmi_set_geometry(this);
1947         if (ret)
1948                 return ret;
1949 
1950         /* Init the nand_ecc_ctrl{} */
1951         ecc->read_page  = gpmi_ecc_read_page;
1952         ecc->write_page = gpmi_ecc_write_page;
1953         ecc->read_oob   = gpmi_ecc_read_oob;
1954         ecc->write_oob  = gpmi_ecc_write_oob;
1955         ecc->read_page_raw = gpmi_ecc_read_page_raw;
1956         ecc->write_page_raw = gpmi_ecc_write_page_raw;
1957         ecc->read_oob_raw = gpmi_ecc_read_oob_raw;
1958         ecc->write_oob_raw = gpmi_ecc_write_oob_raw;
1959         ecc->mode       = NAND_ECC_HW;
1960         ecc->size       = bch_geo->ecc_chunk_size;
1961         ecc->strength   = bch_geo->ecc_strength;
1962         mtd_set_ooblayout(mtd, &gpmi_ooblayout_ops);
1963 
1964         /*
1965          * We only enable the subpage read when:
1966          *  (1) the chip is imx6, and
1967          *  (2) the size of the ECC parity is byte aligned.
1968          */
1969         if (GPMI_IS_MX6(this) &&
1970                 ((bch_geo->gf_len * bch_geo->ecc_strength) % 8) == 0) {
1971                 ecc->read_subpage = gpmi_ecc_read_subpage;
1972                 chip->options |= NAND_SUBPAGE_READ;
1973         }
1974 
1975         /*
1976          * Can we enable the extra features? such as EDO or Sync mode.
1977          *
1978          * We do not check the return value now. That's means if we fail in
1979          * enable the extra features, we still can run in the normal way.
1980          */
1981         gpmi_extra_init(this);
1982 
1983         return 0;
1984 }
1985 
1986 static int gpmi_nand_init(struct gpmi_nand_data *this)
1987 {
1988         struct nand_chip *chip = &this->nand;
1989         struct mtd_info  *mtd = nand_to_mtd(chip);
1990         int ret;
1991 
1992         /* init current chip */
1993         this->current_chip      = -1;
1994 
1995         /* init the MTD data structures */
1996         mtd->name               = "gpmi-nand";
1997         mtd->dev.parent         = this->dev;
1998 
1999         /* init the nand_chip{}, we don't support a 16-bit NAND Flash bus. */
2000         nand_set_controller_data(chip, this);
2001         nand_set_flash_node(chip, this->pdev->dev.of_node);
2002         chip->select_chip       = gpmi_select_chip;
2003         chip->cmd_ctrl          = gpmi_cmd_ctrl;
2004         chip->dev_ready         = gpmi_dev_ready;
2005         chip->read_byte         = gpmi_read_byte;
2006         chip->read_buf          = gpmi_read_buf;
2007         chip->write_buf         = gpmi_write_buf;
2008         chip->badblock_pattern  = &gpmi_bbt_descr;
2009         chip->block_markbad     = gpmi_block_markbad;
2010         chip->options           |= NAND_NO_SUBPAGE_WRITE;
2011 
2012         /* Set up swap_block_mark, must be set before the gpmi_set_geometry() */
2013         this->swap_block_mark = !GPMI_IS_MX23(this);
2014 
2015         /*
2016          * Allocate a temporary DMA buffer for reading ID in the
2017          * nand_scan_ident().
2018          */
2019         this->bch_geometry.payload_size = 1024;
2020         this->bch_geometry.auxiliary_size = 128;
2021         ret = gpmi_alloc_dma_buffer(this);
2022         if (ret)
2023                 goto err_out;
2024 
2025         ret = nand_scan_ident(mtd, GPMI_IS_MX6(this) ? 2 : 1, NULL);
2026         if (ret)
2027                 goto err_out;
2028 
2029         if (chip->bbt_options & NAND_BBT_USE_FLASH) {
2030                 chip->bbt_options |= NAND_BBT_NO_OOB;
2031 
2032                 if (of_property_read_bool(this->dev->of_node,
2033                                                 "fsl,no-blockmark-swap"))
2034                         this->swap_block_mark = false;
2035         }
2036         dev_dbg(this->dev, "Blockmark swapping %sabled\n",
2037                 this->swap_block_mark ? "en" : "dis");
2038 
2039         ret = gpmi_init_last(this);
2040         if (ret)
2041                 goto err_out;
2042 
2043         chip->options |= NAND_SKIP_BBTSCAN;
2044         ret = nand_scan_tail(mtd);
2045         if (ret)
2046                 goto err_out;
2047 
2048         ret = nand_boot_init(this);
2049         if (ret)
2050                 goto err_out;
2051         ret = chip->scan_bbt(mtd);
2052         if (ret)
2053                 goto err_out;
2054 
2055         ret = mtd_device_register(mtd, NULL, 0);
2056         if (ret)
2057                 goto err_out;
2058         return 0;
2059 
2060 err_out:
2061         gpmi_nand_exit(this);
2062         return ret;
2063 }
2064 
2065 static const struct of_device_id gpmi_nand_id_table[] = {
2066         {
2067                 .compatible = "fsl,imx23-gpmi-nand",
2068                 .data = &gpmi_devdata_imx23,
2069         }, {
2070                 .compatible = "fsl,imx28-gpmi-nand",
2071                 .data = &gpmi_devdata_imx28,
2072         }, {
2073                 .compatible = "fsl,imx6q-gpmi-nand",
2074                 .data = &gpmi_devdata_imx6q,
2075         }, {
2076                 .compatible = "fsl,imx6sx-gpmi-nand",
2077                 .data = &gpmi_devdata_imx6sx,
2078         }, {}
2079 };
2080 MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
2081 
2082 static int gpmi_nand_probe(struct platform_device *pdev)
2083 {
2084         struct gpmi_nand_data *this;
2085         const struct of_device_id *of_id;
2086         int ret;
2087 
2088         this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
2089         if (!this)
2090                 return -ENOMEM;
2091 
2092         of_id = of_match_device(gpmi_nand_id_table, &pdev->dev);
2093         if (of_id) {
2094                 this->devdata = of_id->data;
2095         } else {
2096                 dev_err(&pdev->dev, "Failed to find the right device id.\n");
2097                 return -ENODEV;
2098         }
2099 
2100         platform_set_drvdata(pdev, this);
2101         this->pdev  = pdev;
2102         this->dev   = &pdev->dev;
2103 
2104         ret = acquire_resources(this);
2105         if (ret)
2106                 goto exit_acquire_resources;
2107 
2108         ret = init_hardware(this);
2109         if (ret)
2110                 goto exit_nfc_init;
2111 
2112         ret = gpmi_nand_init(this);
2113         if (ret)
2114                 goto exit_nfc_init;
2115 
2116         dev_info(this->dev, "driver registered.\n");
2117 
2118         return 0;
2119 
2120 exit_nfc_init:
2121         release_resources(this);
2122 exit_acquire_resources:
2123 
2124         return ret;
2125 }
2126 
2127 static int gpmi_nand_remove(struct platform_device *pdev)
2128 {
2129         struct gpmi_nand_data *this = platform_get_drvdata(pdev);
2130 
2131         gpmi_nand_exit(this);
2132         release_resources(this);
2133         return 0;
2134 }
2135 
2136 #ifdef CONFIG_PM_SLEEP
2137 static int gpmi_pm_suspend(struct device *dev)
2138 {
2139         struct gpmi_nand_data *this = dev_get_drvdata(dev);
2140 
2141         release_dma_channels(this);
2142         return 0;
2143 }
2144 
2145 static int gpmi_pm_resume(struct device *dev)
2146 {
2147         struct gpmi_nand_data *this = dev_get_drvdata(dev);
2148         int ret;
2149 
2150         ret = acquire_dma_channels(this);
2151         if (ret < 0)
2152                 return ret;
2153 
2154         /* re-init the GPMI registers */
2155         this->flags &= ~GPMI_TIMING_INIT_OK;
2156         ret = gpmi_init(this);
2157         if (ret) {
2158                 dev_err(this->dev, "Error setting GPMI : %d\n", ret);
2159                 return ret;
2160         }
2161 
2162         /* re-init the BCH registers */
2163         ret = bch_set_geometry(this);
2164         if (ret) {
2165                 dev_err(this->dev, "Error setting BCH : %d\n", ret);
2166                 return ret;
2167         }
2168 
2169         /* re-init others */
2170         gpmi_extra_init(this);
2171 
2172         return 0;
2173 }
2174 #endif /* CONFIG_PM_SLEEP */
2175 
2176 static const struct dev_pm_ops gpmi_pm_ops = {
2177         SET_SYSTEM_SLEEP_PM_OPS(gpmi_pm_suspend, gpmi_pm_resume)
2178 };
2179 
2180 static struct platform_driver gpmi_nand_driver = {
2181         .driver = {
2182                 .name = "gpmi-nand",
2183                 .pm = &gpmi_pm_ops,
2184                 .of_match_table = gpmi_nand_id_table,
2185         },
2186         .probe   = gpmi_nand_probe,
2187         .remove  = gpmi_nand_remove,
2188 };
2189 module_platform_driver(gpmi_nand_driver);
2190 
2191 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
2192 MODULE_DESCRIPTION("i.MX GPMI NAND Flash Controller Driver");
2193 MODULE_LICENSE("GPL");
2194 

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