Version:  2.0.40 2.2.26 2.4.37 3.9 3.10 3.11 3.12 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

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

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