Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 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

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

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

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