Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 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

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         int err;
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         err = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
460         if (!err) {
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         int err;
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         err = wait_for_completion_timeout(bch_c, msecs_to_jiffies(1000));
490         if (!err) {
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 
795         this->cmd_buffer        = NULL;
796         this->data_buffer_dma   = NULL;
797         this->page_buffer_virt  = NULL;
798         this->page_buffer_size  =  0;
799 }
800 
801 /* Allocate the DMA buffers */
802 static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this)
803 {
804         struct bch_geometry *geo = &this->bch_geometry;
805         struct device *dev = this->dev;
806         struct mtd_info *mtd = &this->mtd;
807 
808         /* [1] Allocate a command buffer. PAGE_SIZE is enough. */
809         this->cmd_buffer = kzalloc(PAGE_SIZE, GFP_DMA | GFP_KERNEL);
810         if (this->cmd_buffer == NULL)
811                 goto error_alloc;
812 
813         /*
814          * [2] Allocate a read/write data buffer.
815          *     The gpmi_alloc_dma_buffer can be called twice.
816          *     We allocate a PAGE_SIZE length buffer if gpmi_alloc_dma_buffer
817          *     is called before the nand_scan_ident; and we allocate a buffer
818          *     of the real NAND page size when the gpmi_alloc_dma_buffer is
819          *     called after the nand_scan_ident.
820          */
821         this->data_buffer_dma = kzalloc(mtd->writesize ?: PAGE_SIZE,
822                                         GFP_DMA | GFP_KERNEL);
823         if (this->data_buffer_dma == NULL)
824                 goto error_alloc;
825 
826         /*
827          * [3] Allocate the page buffer.
828          *
829          * Both the payload buffer and the auxiliary buffer must appear on
830          * 32-bit boundaries. We presume the size of the payload buffer is a
831          * power of two and is much larger than four, which guarantees the
832          * auxiliary buffer will appear on a 32-bit boundary.
833          */
834         this->page_buffer_size = geo->payload_size + geo->auxiliary_size;
835         this->page_buffer_virt = dma_alloc_coherent(dev, this->page_buffer_size,
836                                         &this->page_buffer_phys, GFP_DMA);
837         if (!this->page_buffer_virt)
838                 goto error_alloc;
839 
840 
841         /* Slice up the page buffer. */
842         this->payload_virt = this->page_buffer_virt;
843         this->payload_phys = this->page_buffer_phys;
844         this->auxiliary_virt = this->payload_virt + geo->payload_size;
845         this->auxiliary_phys = this->payload_phys + geo->payload_size;
846         return 0;
847 
848 error_alloc:
849         gpmi_free_dma_buffer(this);
850         return -ENOMEM;
851 }
852 
853 static void gpmi_cmd_ctrl(struct mtd_info *mtd, int data, unsigned int ctrl)
854 {
855         struct nand_chip *chip = mtd->priv;
856         struct gpmi_nand_data *this = chip->priv;
857         int ret;
858 
859         /*
860          * Every operation begins with a command byte and a series of zero or
861          * more address bytes. These are distinguished by either the Address
862          * Latch Enable (ALE) or Command Latch Enable (CLE) signals being
863          * asserted. When MTD is ready to execute the command, it will deassert
864          * both latch enables.
865          *
866          * Rather than run a separate DMA operation for every single byte, we
867          * queue them up and run a single DMA operation for the entire series
868          * of command and data bytes. NAND_CMD_NONE means the END of the queue.
869          */
870         if ((ctrl & (NAND_ALE | NAND_CLE))) {
871                 if (data != NAND_CMD_NONE)
872                         this->cmd_buffer[this->command_length++] = data;
873                 return;
874         }
875 
876         if (!this->command_length)
877                 return;
878 
879         ret = gpmi_send_command(this);
880         if (ret)
881                 dev_err(this->dev, "Chip: %u, Error %d\n",
882                         this->current_chip, ret);
883 
884         this->command_length = 0;
885 }
886 
887 static int gpmi_dev_ready(struct mtd_info *mtd)
888 {
889         struct nand_chip *chip = mtd->priv;
890         struct gpmi_nand_data *this = chip->priv;
891 
892         return gpmi_is_ready(this, this->current_chip);
893 }
894 
895 static void gpmi_select_chip(struct mtd_info *mtd, int chipnr)
896 {
897         struct nand_chip *chip = mtd->priv;
898         struct gpmi_nand_data *this = chip->priv;
899 
900         if ((this->current_chip < 0) && (chipnr >= 0))
901                 gpmi_begin(this);
902         else if ((this->current_chip >= 0) && (chipnr < 0))
903                 gpmi_end(this);
904 
905         this->current_chip = chipnr;
906 }
907 
908 static void gpmi_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
909 {
910         struct nand_chip *chip = mtd->priv;
911         struct gpmi_nand_data *this = chip->priv;
912 
913         dev_dbg(this->dev, "len is %d\n", len);
914         this->upper_buf = buf;
915         this->upper_len = len;
916 
917         gpmi_read_data(this);
918 }
919 
920 static void gpmi_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
921 {
922         struct nand_chip *chip = mtd->priv;
923         struct gpmi_nand_data *this = chip->priv;
924 
925         dev_dbg(this->dev, "len is %d\n", len);
926         this->upper_buf = (uint8_t *)buf;
927         this->upper_len = len;
928 
929         gpmi_send_data(this);
930 }
931 
932 static uint8_t gpmi_read_byte(struct mtd_info *mtd)
933 {
934         struct nand_chip *chip = mtd->priv;
935         struct gpmi_nand_data *this = chip->priv;
936         uint8_t *buf = this->data_buffer_dma;
937 
938         gpmi_read_buf(mtd, buf, 1);
939         return buf[0];
940 }
941 
942 /*
943  * Handles block mark swapping.
944  * It can be called in swapping the block mark, or swapping it back,
945  * because the the operations are the same.
946  */
947 static void block_mark_swapping(struct gpmi_nand_data *this,
948                                 void *payload, void *auxiliary)
949 {
950         struct bch_geometry *nfc_geo = &this->bch_geometry;
951         unsigned char *p;
952         unsigned char *a;
953         unsigned int  bit;
954         unsigned char mask;
955         unsigned char from_data;
956         unsigned char from_oob;
957 
958         if (!this->swap_block_mark)
959                 return;
960 
961         /*
962          * If control arrives here, we're swapping. Make some convenience
963          * variables.
964          */
965         bit = nfc_geo->block_mark_bit_offset;
966         p   = payload + nfc_geo->block_mark_byte_offset;
967         a   = auxiliary;
968 
969         /*
970          * Get the byte from the data area that overlays the block mark. Since
971          * the ECC engine applies its own view to the bits in the page, the
972          * physical block mark won't (in general) appear on a byte boundary in
973          * the data.
974          */
975         from_data = (p[0] >> bit) | (p[1] << (8 - bit));
976 
977         /* Get the byte from the OOB. */
978         from_oob = a[0];
979 
980         /* Swap them. */
981         a[0] = from_data;
982 
983         mask = (0x1 << bit) - 1;
984         p[0] = (p[0] & mask) | (from_oob << bit);
985 
986         mask = ~0 << bit;
987         p[1] = (p[1] & mask) | (from_oob >> (8 - bit));
988 }
989 
990 static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
991                                 uint8_t *buf, int oob_required, int page)
992 {
993         struct gpmi_nand_data *this = chip->priv;
994         struct bch_geometry *nfc_geo = &this->bch_geometry;
995         void          *payload_virt;
996         dma_addr_t    payload_phys;
997         void          *auxiliary_virt;
998         dma_addr_t    auxiliary_phys;
999         unsigned int  i;
1000         unsigned char *status;
1001         unsigned int  max_bitflips = 0;
1002         int           ret;
1003 
1004         dev_dbg(this->dev, "page number is : %d\n", page);
1005         ret = read_page_prepare(this, buf, nfc_geo->payload_size,
1006                                         this->payload_virt, this->payload_phys,
1007                                         nfc_geo->payload_size,
1008                                         &payload_virt, &payload_phys);
1009         if (ret) {
1010                 dev_err(this->dev, "Inadequate DMA buffer\n");
1011                 ret = -ENOMEM;
1012                 return ret;
1013         }
1014         auxiliary_virt = this->auxiliary_virt;
1015         auxiliary_phys = this->auxiliary_phys;
1016 
1017         /* go! */
1018         ret = gpmi_read_page(this, payload_phys, auxiliary_phys);
1019         read_page_end(this, buf, nfc_geo->payload_size,
1020                         this->payload_virt, this->payload_phys,
1021                         nfc_geo->payload_size,
1022                         payload_virt, payload_phys);
1023         if (ret) {
1024                 dev_err(this->dev, "Error in ECC-based read: %d\n", ret);
1025                 return ret;
1026         }
1027 
1028         /* handle the block mark swapping */
1029         block_mark_swapping(this, payload_virt, auxiliary_virt);
1030 
1031         /* Loop over status bytes, accumulating ECC status. */
1032         status = auxiliary_virt + nfc_geo->auxiliary_status_offset;
1033 
1034         for (i = 0; i < nfc_geo->ecc_chunk_count; i++, status++) {
1035                 if ((*status == STATUS_GOOD) || (*status == STATUS_ERASED))
1036                         continue;
1037 
1038                 if (*status == STATUS_UNCORRECTABLE) {
1039                         mtd->ecc_stats.failed++;
1040                         continue;
1041                 }
1042                 mtd->ecc_stats.corrected += *status;
1043                 max_bitflips = max_t(unsigned int, max_bitflips, *status);
1044         }
1045 
1046         if (oob_required) {
1047                 /*
1048                  * It's time to deliver the OOB bytes. See gpmi_ecc_read_oob()
1049                  * for details about our policy for delivering the OOB.
1050                  *
1051                  * We fill the caller's buffer with set bits, and then copy the
1052                  * block mark to th caller's buffer. Note that, if block mark
1053                  * swapping was necessary, it has already been done, so we can
1054                  * rely on the first byte of the auxiliary buffer to contain
1055                  * the block mark.
1056                  */
1057                 memset(chip->oob_poi, ~0, mtd->oobsize);
1058                 chip->oob_poi[0] = ((uint8_t *) auxiliary_virt)[0];
1059         }
1060 
1061         read_page_swap_end(this, buf, nfc_geo->payload_size,
1062                         this->payload_virt, this->payload_phys,
1063                         nfc_geo->payload_size,
1064                         payload_virt, payload_phys);
1065 
1066         return max_bitflips;
1067 }
1068 
1069 /* Fake a virtual small page for the subpage read */
1070 static int gpmi_ecc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1071                         uint32_t offs, uint32_t len, uint8_t *buf, int page)
1072 {
1073         struct gpmi_nand_data *this = chip->priv;
1074         void __iomem *bch_regs = this->resources.bch_regs;
1075         struct bch_geometry old_geo = this->bch_geometry;
1076         struct bch_geometry *geo = &this->bch_geometry;
1077         int size = chip->ecc.size; /* ECC chunk size */
1078         int meta, n, page_size;
1079         u32 r1_old, r2_old, r1_new, r2_new;
1080         unsigned int max_bitflips;
1081         int first, last, marker_pos;
1082         int ecc_parity_size;
1083         int col = 0;
1084         int old_swap_block_mark = this->swap_block_mark;
1085 
1086         /* The size of ECC parity */
1087         ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
1088 
1089         /* Align it with the chunk size */
1090         first = offs / size;
1091         last = (offs + len - 1) / size;
1092 
1093         if (this->swap_block_mark) {
1094                 /*
1095                  * Find the chunk which contains the Block Marker.
1096                  * If this chunk is in the range of [first, last],
1097                  * we have to read out the whole page.
1098                  * Why? since we had swapped the data at the position of Block
1099                  * Marker to the metadata which is bound with the chunk 0.
1100                  */
1101                 marker_pos = geo->block_mark_byte_offset / size;
1102                 if (last >= marker_pos && first <= marker_pos) {
1103                         dev_dbg(this->dev,
1104                                 "page:%d, first:%d, last:%d, marker at:%d\n",
1105                                 page, first, last, marker_pos);
1106                         return gpmi_ecc_read_page(mtd, chip, buf, 0, page);
1107                 }
1108         }
1109 
1110         meta = geo->metadata_size;
1111         if (first) {
1112                 col = meta + (size + ecc_parity_size) * first;
1113                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, col, -1);
1114 
1115                 meta = 0;
1116                 buf = buf + first * size;
1117         }
1118 
1119         /* Save the old environment */
1120         r1_old = r1_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT0);
1121         r2_old = r2_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT1);
1122 
1123         /* change the BCH registers and bch_geometry{} */
1124         n = last - first + 1;
1125         page_size = meta + (size + ecc_parity_size) * n;
1126 
1127         r1_new &= ~(BM_BCH_FLASH0LAYOUT0_NBLOCKS |
1128                         BM_BCH_FLASH0LAYOUT0_META_SIZE);
1129         r1_new |= BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1)
1130                         | BF_BCH_FLASH0LAYOUT0_META_SIZE(meta);
1131         writel(r1_new, bch_regs + HW_BCH_FLASH0LAYOUT0);
1132 
1133         r2_new &= ~BM_BCH_FLASH0LAYOUT1_PAGE_SIZE;
1134         r2_new |= BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size);
1135         writel(r2_new, bch_regs + HW_BCH_FLASH0LAYOUT1);
1136 
1137         geo->ecc_chunk_count = n;
1138         geo->payload_size = n * size;
1139         geo->page_size = page_size;
1140         geo->auxiliary_status_offset = ALIGN(meta, 4);
1141 
1142         dev_dbg(this->dev, "page:%d(%d:%d)%d, chunk:(%d:%d), BCH PG size:%d\n",
1143                 page, offs, len, col, first, n, page_size);
1144 
1145         /* Read the subpage now */
1146         this->swap_block_mark = false;
1147         max_bitflips = gpmi_ecc_read_page(mtd, chip, buf, 0, page);
1148 
1149         /* Restore */
1150         writel(r1_old, bch_regs + HW_BCH_FLASH0LAYOUT0);
1151         writel(r2_old, bch_regs + HW_BCH_FLASH0LAYOUT1);
1152         this->bch_geometry = old_geo;
1153         this->swap_block_mark = old_swap_block_mark;
1154 
1155         return max_bitflips;
1156 }
1157 
1158 static int gpmi_ecc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
1159                                 const uint8_t *buf, int oob_required)
1160 {
1161         struct gpmi_nand_data *this = chip->priv;
1162         struct bch_geometry *nfc_geo = &this->bch_geometry;
1163         const void *payload_virt;
1164         dma_addr_t payload_phys;
1165         const void *auxiliary_virt;
1166         dma_addr_t auxiliary_phys;
1167         int        ret;
1168 
1169         dev_dbg(this->dev, "ecc write page.\n");
1170         if (this->swap_block_mark) {
1171                 /*
1172                  * If control arrives here, we're doing block mark swapping.
1173                  * Since we can't modify the caller's buffers, we must copy them
1174                  * into our own.
1175                  */
1176                 memcpy(this->payload_virt, buf, mtd->writesize);
1177                 payload_virt = this->payload_virt;
1178                 payload_phys = this->payload_phys;
1179 
1180                 memcpy(this->auxiliary_virt, chip->oob_poi,
1181                                 nfc_geo->auxiliary_size);
1182                 auxiliary_virt = this->auxiliary_virt;
1183                 auxiliary_phys = this->auxiliary_phys;
1184 
1185                 /* Handle block mark swapping. */
1186                 block_mark_swapping(this,
1187                                 (void *)payload_virt, (void *)auxiliary_virt);
1188         } else {
1189                 /*
1190                  * If control arrives here, we're not doing block mark swapping,
1191                  * so we can to try and use the caller's buffers.
1192                  */
1193                 ret = send_page_prepare(this,
1194                                 buf, mtd->writesize,
1195                                 this->payload_virt, this->payload_phys,
1196                                 nfc_geo->payload_size,
1197                                 &payload_virt, &payload_phys);
1198                 if (ret) {
1199                         dev_err(this->dev, "Inadequate payload DMA buffer\n");
1200                         return 0;
1201                 }
1202 
1203                 ret = send_page_prepare(this,
1204                                 chip->oob_poi, mtd->oobsize,
1205                                 this->auxiliary_virt, this->auxiliary_phys,
1206                                 nfc_geo->auxiliary_size,
1207                                 &auxiliary_virt, &auxiliary_phys);
1208                 if (ret) {
1209                         dev_err(this->dev, "Inadequate auxiliary DMA buffer\n");
1210                         goto exit_auxiliary;
1211                 }
1212         }
1213 
1214         /* Ask the NFC. */
1215         ret = gpmi_send_page(this, payload_phys, auxiliary_phys);
1216         if (ret)
1217                 dev_err(this->dev, "Error in ECC-based write: %d\n", ret);
1218 
1219         if (!this->swap_block_mark) {
1220                 send_page_end(this, chip->oob_poi, mtd->oobsize,
1221                                 this->auxiliary_virt, this->auxiliary_phys,
1222                                 nfc_geo->auxiliary_size,
1223                                 auxiliary_virt, auxiliary_phys);
1224 exit_auxiliary:
1225                 send_page_end(this, buf, mtd->writesize,
1226                                 this->payload_virt, this->payload_phys,
1227                                 nfc_geo->payload_size,
1228                                 payload_virt, payload_phys);
1229         }
1230 
1231         return 0;
1232 }
1233 
1234 /*
1235  * There are several places in this driver where we have to handle the OOB and
1236  * block marks. This is the function where things are the most complicated, so
1237  * this is where we try to explain it all. All the other places refer back to
1238  * here.
1239  *
1240  * These are the rules, in order of decreasing importance:
1241  *
1242  * 1) Nothing the caller does can be allowed to imperil the block mark.
1243  *
1244  * 2) In read operations, the first byte of the OOB we return must reflect the
1245  *    true state of the block mark, no matter where that block mark appears in
1246  *    the physical page.
1247  *
1248  * 3) ECC-based read operations return an OOB full of set bits (since we never
1249  *    allow ECC-based writes to the OOB, it doesn't matter what ECC-based reads
1250  *    return).
1251  *
1252  * 4) "Raw" read operations return a direct view of the physical bytes in the
1253  *    page, using the conventional definition of which bytes are data and which
1254  *    are OOB. This gives the caller a way to see the actual, physical bytes
1255  *    in the page, without the distortions applied by our ECC engine.
1256  *
1257  *
1258  * What we do for this specific read operation depends on two questions:
1259  *
1260  * 1) Are we doing a "raw" read, or an ECC-based read?
1261  *
1262  * 2) Are we using block mark swapping or transcription?
1263  *
1264  * There are four cases, illustrated by the following Karnaugh map:
1265  *
1266  *                    |           Raw           |         ECC-based       |
1267  *       -------------+-------------------------+-------------------------+
1268  *                    | Read the conventional   |                         |
1269  *                    | OOB at the end of the   |                         |
1270  *       Swapping     | page and return it. It  |                         |
1271  *                    | contains exactly what   |                         |
1272  *                    | we want.                | Read the block mark and |
1273  *       -------------+-------------------------+ return it in a buffer   |
1274  *                    | Read the conventional   | full of set bits.       |
1275  *                    | OOB at the end of the   |                         |
1276  *                    | page and also the block |                         |
1277  *       Transcribing | mark in the metadata.   |                         |
1278  *                    | Copy the block mark     |                         |
1279  *                    | into the first byte of  |                         |
1280  *                    | the OOB.                |                         |
1281  *       -------------+-------------------------+-------------------------+
1282  *
1283  * Note that we break rule #4 in the Transcribing/Raw case because we're not
1284  * giving an accurate view of the actual, physical bytes in the page (we're
1285  * overwriting the block mark). That's OK because it's more important to follow
1286  * rule #2.
1287  *
1288  * It turns out that knowing whether we want an "ECC-based" or "raw" read is not
1289  * easy. When reading a page, for example, the NAND Flash MTD code calls our
1290  * ecc.read_page or ecc.read_page_raw function. Thus, the fact that MTD wants an
1291  * ECC-based or raw view of the page is implicit in which function it calls
1292  * (there is a similar pair of ECC-based/raw functions for writing).
1293  *
1294  * FIXME: The following paragraph is incorrect, now that there exist
1295  * ecc.read_oob_raw and ecc.write_oob_raw functions.
1296  *
1297  * Since MTD assumes the OOB is not covered by ECC, there is no pair of
1298  * ECC-based/raw functions for reading or or writing the OOB. The fact that the
1299  * caller wants an ECC-based or raw view of the page is not propagated down to
1300  * this driver.
1301  */
1302 static int gpmi_ecc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
1303                                 int page)
1304 {
1305         struct gpmi_nand_data *this = chip->priv;
1306 
1307         dev_dbg(this->dev, "page number is %d\n", page);
1308         /* clear the OOB buffer */
1309         memset(chip->oob_poi, ~0, mtd->oobsize);
1310 
1311         /* Read out the conventional OOB. */
1312         chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
1313         chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1314 
1315         /*
1316          * Now, we want to make sure the block mark is correct. In the
1317          * non-transcribing case (!GPMI_IS_MX23()), we already have it.
1318          * Otherwise, we need to explicitly read it.
1319          */
1320         if (GPMI_IS_MX23(this)) {
1321                 /* Read the block mark into the first byte of the OOB buffer. */
1322                 chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1323                 chip->oob_poi[0] = chip->read_byte(mtd);
1324         }
1325 
1326         return 0;
1327 }
1328 
1329 static int
1330 gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page)
1331 {
1332         struct nand_oobfree *of = mtd->ecclayout->oobfree;
1333         int status = 0;
1334 
1335         /* Do we have available oob area? */
1336         if (!of->length)
1337                 return -EPERM;
1338 
1339         if (!nand_is_slc(chip))
1340                 return -EPERM;
1341 
1342         chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize + of->offset, page);
1343         chip->write_buf(mtd, chip->oob_poi + of->offset, of->length);
1344         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1345 
1346         status = chip->waitfunc(mtd, chip);
1347         return status & NAND_STATUS_FAIL ? -EIO : 0;
1348 }
1349 
1350 static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs)
1351 {
1352         struct nand_chip *chip = mtd->priv;
1353         struct gpmi_nand_data *this = chip->priv;
1354         int ret = 0;
1355         uint8_t *block_mark;
1356         int column, page, status, chipnr;
1357 
1358         chipnr = (int)(ofs >> chip->chip_shift);
1359         chip->select_chip(mtd, chipnr);
1360 
1361         column = !GPMI_IS_MX23(this) ? mtd->writesize : 0;
1362 
1363         /* Write the block mark. */
1364         block_mark = this->data_buffer_dma;
1365         block_mark[0] = 0; /* bad block marker */
1366 
1367         /* Shift to get page */
1368         page = (int)(ofs >> chip->page_shift);
1369 
1370         chip->cmdfunc(mtd, NAND_CMD_SEQIN, column, page);
1371         chip->write_buf(mtd, block_mark, 1);
1372         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1373 
1374         status = chip->waitfunc(mtd, chip);
1375         if (status & NAND_STATUS_FAIL)
1376                 ret = -EIO;
1377 
1378         chip->select_chip(mtd, -1);
1379 
1380         return ret;
1381 }
1382 
1383 static int nand_boot_set_geometry(struct gpmi_nand_data *this)
1384 {
1385         struct boot_rom_geometry *geometry = &this->rom_geometry;
1386 
1387         /*
1388          * Set the boot block stride size.
1389          *
1390          * In principle, we should be reading this from the OTP bits, since
1391          * that's where the ROM is going to get it. In fact, we don't have any
1392          * way to read the OTP bits, so we go with the default and hope for the
1393          * best.
1394          */
1395         geometry->stride_size_in_pages = 64;
1396 
1397         /*
1398          * Set the search area stride exponent.
1399          *
1400          * In principle, we should be reading this from the OTP bits, since
1401          * that's where the ROM is going to get it. In fact, we don't have any
1402          * way to read the OTP bits, so we go with the default and hope for the
1403          * best.
1404          */
1405         geometry->search_area_stride_exponent = 2;
1406         return 0;
1407 }
1408 
1409 static const char  *fingerprint = "STMP";
1410 static int mx23_check_transcription_stamp(struct gpmi_nand_data *this)
1411 {
1412         struct boot_rom_geometry *rom_geo = &this->rom_geometry;
1413         struct device *dev = this->dev;
1414         struct mtd_info *mtd = &this->mtd;
1415         struct nand_chip *chip = &this->nand;
1416         unsigned int search_area_size_in_strides;
1417         unsigned int stride;
1418         unsigned int page;
1419         uint8_t *buffer = chip->buffers->databuf;
1420         int saved_chip_number;
1421         int found_an_ncb_fingerprint = false;
1422 
1423         /* Compute the number of strides in a search area. */
1424         search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
1425 
1426         saved_chip_number = this->current_chip;
1427         chip->select_chip(mtd, 0);
1428 
1429         /*
1430          * Loop through the first search area, looking for the NCB fingerprint.
1431          */
1432         dev_dbg(dev, "Scanning for an NCB fingerprint...\n");
1433 
1434         for (stride = 0; stride < search_area_size_in_strides; stride++) {
1435                 /* Compute the page addresses. */
1436                 page = stride * rom_geo->stride_size_in_pages;
1437 
1438                 dev_dbg(dev, "Looking for a fingerprint in page 0x%x\n", page);
1439 
1440                 /*
1441                  * Read the NCB fingerprint. The fingerprint is four bytes long
1442                  * and starts in the 12th byte of the page.
1443                  */
1444                 chip->cmdfunc(mtd, NAND_CMD_READ0, 12, page);
1445                 chip->read_buf(mtd, buffer, strlen(fingerprint));
1446 
1447                 /* Look for the fingerprint. */
1448                 if (!memcmp(buffer, fingerprint, strlen(fingerprint))) {
1449                         found_an_ncb_fingerprint = true;
1450                         break;
1451                 }
1452 
1453         }
1454 
1455         chip->select_chip(mtd, saved_chip_number);
1456 
1457         if (found_an_ncb_fingerprint)
1458                 dev_dbg(dev, "\tFound a fingerprint\n");
1459         else
1460                 dev_dbg(dev, "\tNo fingerprint found\n");
1461         return found_an_ncb_fingerprint;
1462 }
1463 
1464 /* Writes a transcription stamp. */
1465 static int mx23_write_transcription_stamp(struct gpmi_nand_data *this)
1466 {
1467         struct device *dev = this->dev;
1468         struct boot_rom_geometry *rom_geo = &this->rom_geometry;
1469         struct mtd_info *mtd = &this->mtd;
1470         struct nand_chip *chip = &this->nand;
1471         unsigned int block_size_in_pages;
1472         unsigned int search_area_size_in_strides;
1473         unsigned int search_area_size_in_pages;
1474         unsigned int search_area_size_in_blocks;
1475         unsigned int block;
1476         unsigned int stride;
1477         unsigned int page;
1478         uint8_t      *buffer = chip->buffers->databuf;
1479         int saved_chip_number;
1480         int status;
1481 
1482         /* Compute the search area geometry. */
1483         block_size_in_pages = mtd->erasesize / mtd->writesize;
1484         search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
1485         search_area_size_in_pages = search_area_size_in_strides *
1486                                         rom_geo->stride_size_in_pages;
1487         search_area_size_in_blocks =
1488                   (search_area_size_in_pages + (block_size_in_pages - 1)) /
1489                                     block_size_in_pages;
1490 
1491         dev_dbg(dev, "Search Area Geometry :\n");
1492         dev_dbg(dev, "\tin Blocks : %u\n", search_area_size_in_blocks);
1493         dev_dbg(dev, "\tin Strides: %u\n", search_area_size_in_strides);
1494         dev_dbg(dev, "\tin Pages  : %u\n", search_area_size_in_pages);
1495 
1496         /* Select chip 0. */
1497         saved_chip_number = this->current_chip;
1498         chip->select_chip(mtd, 0);
1499 
1500         /* Loop over blocks in the first search area, erasing them. */
1501         dev_dbg(dev, "Erasing the search area...\n");
1502 
1503         for (block = 0; block < search_area_size_in_blocks; block++) {
1504                 /* Compute the page address. */
1505                 page = block * block_size_in_pages;
1506 
1507                 /* Erase this block. */
1508                 dev_dbg(dev, "\tErasing block 0x%x\n", block);
1509                 chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
1510                 chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
1511 
1512                 /* Wait for the erase to finish. */
1513                 status = chip->waitfunc(mtd, chip);
1514                 if (status & NAND_STATUS_FAIL)
1515                         dev_err(dev, "[%s] Erase failed.\n", __func__);
1516         }
1517 
1518         /* Write the NCB fingerprint into the page buffer. */
1519         memset(buffer, ~0, mtd->writesize);
1520         memcpy(buffer + 12, fingerprint, strlen(fingerprint));
1521 
1522         /* Loop through the first search area, writing NCB fingerprints. */
1523         dev_dbg(dev, "Writing NCB fingerprints...\n");
1524         for (stride = 0; stride < search_area_size_in_strides; stride++) {
1525                 /* Compute the page addresses. */
1526                 page = stride * rom_geo->stride_size_in_pages;
1527 
1528                 /* Write the first page of the current stride. */
1529                 dev_dbg(dev, "Writing an NCB fingerprint in page 0x%x\n", page);
1530                 chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
1531                 chip->ecc.write_page_raw(mtd, chip, buffer, 0);
1532                 chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1533 
1534                 /* Wait for the write to finish. */
1535                 status = chip->waitfunc(mtd, chip);
1536                 if (status & NAND_STATUS_FAIL)
1537                         dev_err(dev, "[%s] Write failed.\n", __func__);
1538         }
1539 
1540         /* Deselect chip 0. */
1541         chip->select_chip(mtd, saved_chip_number);
1542         return 0;
1543 }
1544 
1545 static int mx23_boot_init(struct gpmi_nand_data  *this)
1546 {
1547         struct device *dev = this->dev;
1548         struct nand_chip *chip = &this->nand;
1549         struct mtd_info *mtd = &this->mtd;
1550         unsigned int block_count;
1551         unsigned int block;
1552         int     chipnr;
1553         int     page;
1554         loff_t  byte;
1555         uint8_t block_mark;
1556         int     ret = 0;
1557 
1558         /*
1559          * If control arrives here, we can't use block mark swapping, which
1560          * means we're forced to use transcription. First, scan for the
1561          * transcription stamp. If we find it, then we don't have to do
1562          * anything -- the block marks are already transcribed.
1563          */
1564         if (mx23_check_transcription_stamp(this))
1565                 return 0;
1566 
1567         /*
1568          * If control arrives here, we couldn't find a transcription stamp, so
1569          * so we presume the block marks are in the conventional location.
1570          */
1571         dev_dbg(dev, "Transcribing bad block marks...\n");
1572 
1573         /* Compute the number of blocks in the entire medium. */
1574         block_count = chip->chipsize >> chip->phys_erase_shift;
1575 
1576         /*
1577          * Loop over all the blocks in the medium, transcribing block marks as
1578          * we go.
1579          */
1580         for (block = 0; block < block_count; block++) {
1581                 /*
1582                  * Compute the chip, page and byte addresses for this block's
1583                  * conventional mark.
1584                  */
1585                 chipnr = block >> (chip->chip_shift - chip->phys_erase_shift);
1586                 page = block << (chip->phys_erase_shift - chip->page_shift);
1587                 byte = block <<  chip->phys_erase_shift;
1588 
1589                 /* Send the command to read the conventional block mark. */
1590                 chip->select_chip(mtd, chipnr);
1591                 chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
1592                 block_mark = chip->read_byte(mtd);
1593                 chip->select_chip(mtd, -1);
1594 
1595                 /*
1596                  * Check if the block is marked bad. If so, we need to mark it
1597                  * again, but this time the result will be a mark in the
1598                  * location where we transcribe block marks.
1599                  */
1600                 if (block_mark != 0xff) {
1601                         dev_dbg(dev, "Transcribing mark in block %u\n", block);
1602                         ret = chip->block_markbad(mtd, byte);
1603                         if (ret)
1604                                 dev_err(dev,
1605                                         "Failed to mark block bad with ret %d\n",
1606                                         ret);
1607                 }
1608         }
1609 
1610         /* Write the stamp that indicates we've transcribed the block marks. */
1611         mx23_write_transcription_stamp(this);
1612         return 0;
1613 }
1614 
1615 static int nand_boot_init(struct gpmi_nand_data  *this)
1616 {
1617         nand_boot_set_geometry(this);
1618 
1619         /* This is ROM arch-specific initilization before the BBT scanning. */
1620         if (GPMI_IS_MX23(this))
1621                 return mx23_boot_init(this);
1622         return 0;
1623 }
1624 
1625 static int gpmi_set_geometry(struct gpmi_nand_data *this)
1626 {
1627         int ret;
1628 
1629         /* Free the temporary DMA memory for reading ID. */
1630         gpmi_free_dma_buffer(this);
1631 
1632         /* Set up the NFC geometry which is used by BCH. */
1633         ret = bch_set_geometry(this);
1634         if (ret) {
1635                 dev_err(this->dev, "Error setting BCH geometry : %d\n", ret);
1636                 return ret;
1637         }
1638 
1639         /* Alloc the new DMA buffers according to the pagesize and oobsize */
1640         return gpmi_alloc_dma_buffer(this);
1641 }
1642 
1643 static void gpmi_nand_exit(struct gpmi_nand_data *this)
1644 {
1645         nand_release(&this->mtd);
1646         gpmi_free_dma_buffer(this);
1647 }
1648 
1649 static int gpmi_init_last(struct gpmi_nand_data *this)
1650 {
1651         struct mtd_info *mtd = &this->mtd;
1652         struct nand_chip *chip = mtd->priv;
1653         struct nand_ecc_ctrl *ecc = &chip->ecc;
1654         struct bch_geometry *bch_geo = &this->bch_geometry;
1655         int ret;
1656 
1657         /* Set up the medium geometry */
1658         ret = gpmi_set_geometry(this);
1659         if (ret)
1660                 return ret;
1661 
1662         /* Init the nand_ecc_ctrl{} */
1663         ecc->read_page  = gpmi_ecc_read_page;
1664         ecc->write_page = gpmi_ecc_write_page;
1665         ecc->read_oob   = gpmi_ecc_read_oob;
1666         ecc->write_oob  = gpmi_ecc_write_oob;
1667         ecc->mode       = NAND_ECC_HW;
1668         ecc->size       = bch_geo->ecc_chunk_size;
1669         ecc->strength   = bch_geo->ecc_strength;
1670         ecc->layout     = &gpmi_hw_ecclayout;
1671 
1672         /*
1673          * We only enable the subpage read when:
1674          *  (1) the chip is imx6, and
1675          *  (2) the size of the ECC parity is byte aligned.
1676          */
1677         if (GPMI_IS_MX6(this) &&
1678                 ((bch_geo->gf_len * bch_geo->ecc_strength) % 8) == 0) {
1679                 ecc->read_subpage = gpmi_ecc_read_subpage;
1680                 chip->options |= NAND_SUBPAGE_READ;
1681         }
1682 
1683         /*
1684          * Can we enable the extra features? such as EDO or Sync mode.
1685          *
1686          * We do not check the return value now. That's means if we fail in
1687          * enable the extra features, we still can run in the normal way.
1688          */
1689         gpmi_extra_init(this);
1690 
1691         return 0;
1692 }
1693 
1694 static int gpmi_nand_init(struct gpmi_nand_data *this)
1695 {
1696         struct mtd_info  *mtd = &this->mtd;
1697         struct nand_chip *chip = &this->nand;
1698         struct mtd_part_parser_data ppdata = {};
1699         int ret;
1700 
1701         /* init current chip */
1702         this->current_chip      = -1;
1703 
1704         /* init the MTD data structures */
1705         mtd->priv               = chip;
1706         mtd->name               = "gpmi-nand";
1707         mtd->owner              = THIS_MODULE;
1708 
1709         /* init the nand_chip{}, we don't support a 16-bit NAND Flash bus. */
1710         chip->priv              = this;
1711         chip->select_chip       = gpmi_select_chip;
1712         chip->cmd_ctrl          = gpmi_cmd_ctrl;
1713         chip->dev_ready         = gpmi_dev_ready;
1714         chip->read_byte         = gpmi_read_byte;
1715         chip->read_buf          = gpmi_read_buf;
1716         chip->write_buf         = gpmi_write_buf;
1717         chip->badblock_pattern  = &gpmi_bbt_descr;
1718         chip->block_markbad     = gpmi_block_markbad;
1719         chip->options           |= NAND_NO_SUBPAGE_WRITE;
1720 
1721         /* Set up swap_block_mark, must be set before the gpmi_set_geometry() */
1722         this->swap_block_mark = !GPMI_IS_MX23(this);
1723 
1724         if (of_get_nand_on_flash_bbt(this->dev->of_node)) {
1725                 chip->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
1726 
1727                 if (of_property_read_bool(this->dev->of_node,
1728                                                 "fsl,no-blockmark-swap"))
1729                         this->swap_block_mark = false;
1730         }
1731         dev_dbg(this->dev, "Blockmark swapping %sabled\n",
1732                 this->swap_block_mark ? "en" : "dis");
1733 
1734         /*
1735          * Allocate a temporary DMA buffer for reading ID in the
1736          * nand_scan_ident().
1737          */
1738         this->bch_geometry.payload_size = 1024;
1739         this->bch_geometry.auxiliary_size = 128;
1740         ret = gpmi_alloc_dma_buffer(this);
1741         if (ret)
1742                 goto err_out;
1743 
1744         ret = nand_scan_ident(mtd, GPMI_IS_MX6(this) ? 2 : 1, NULL);
1745         if (ret)
1746                 goto err_out;
1747 
1748         ret = gpmi_init_last(this);
1749         if (ret)
1750                 goto err_out;
1751 
1752         chip->options |= NAND_SKIP_BBTSCAN;
1753         ret = nand_scan_tail(mtd);
1754         if (ret)
1755                 goto err_out;
1756 
1757         ret = nand_boot_init(this);
1758         if (ret)
1759                 goto err_out;
1760         chip->scan_bbt(mtd);
1761 
1762         ppdata.of_node = this->pdev->dev.of_node;
1763         ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
1764         if (ret)
1765                 goto err_out;
1766         return 0;
1767 
1768 err_out:
1769         gpmi_nand_exit(this);
1770         return ret;
1771 }
1772 
1773 static const struct of_device_id gpmi_nand_id_table[] = {
1774         {
1775                 .compatible = "fsl,imx23-gpmi-nand",
1776                 .data = &gpmi_devdata_imx23,
1777         }, {
1778                 .compatible = "fsl,imx28-gpmi-nand",
1779                 .data = &gpmi_devdata_imx28,
1780         }, {
1781                 .compatible = "fsl,imx6q-gpmi-nand",
1782                 .data = &gpmi_devdata_imx6q,
1783         }, {
1784                 .compatible = "fsl,imx6sx-gpmi-nand",
1785                 .data = &gpmi_devdata_imx6sx,
1786         }, {}
1787 };
1788 MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
1789 
1790 static int gpmi_nand_probe(struct platform_device *pdev)
1791 {
1792         struct gpmi_nand_data *this;
1793         const struct of_device_id *of_id;
1794         int ret;
1795 
1796         this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
1797         if (!this)
1798                 return -ENOMEM;
1799 
1800         of_id = of_match_device(gpmi_nand_id_table, &pdev->dev);
1801         if (of_id) {
1802                 this->devdata = of_id->data;
1803         } else {
1804                 dev_err(&pdev->dev, "Failed to find the right device id.\n");
1805                 return -ENODEV;
1806         }
1807 
1808         platform_set_drvdata(pdev, this);
1809         this->pdev  = pdev;
1810         this->dev   = &pdev->dev;
1811 
1812         ret = acquire_resources(this);
1813         if (ret)
1814                 goto exit_acquire_resources;
1815 
1816         ret = init_hardware(this);
1817         if (ret)
1818                 goto exit_nfc_init;
1819 
1820         ret = gpmi_nand_init(this);
1821         if (ret)
1822                 goto exit_nfc_init;
1823 
1824         dev_info(this->dev, "driver registered.\n");
1825 
1826         return 0;
1827 
1828 exit_nfc_init:
1829         release_resources(this);
1830 exit_acquire_resources:
1831         dev_err(this->dev, "driver registration failed: %d\n", ret);
1832 
1833         return ret;
1834 }
1835 
1836 static int gpmi_nand_remove(struct platform_device *pdev)
1837 {
1838         struct gpmi_nand_data *this = platform_get_drvdata(pdev);
1839 
1840         gpmi_nand_exit(this);
1841         release_resources(this);
1842         return 0;
1843 }
1844 
1845 static struct platform_driver gpmi_nand_driver = {
1846         .driver = {
1847                 .name = "gpmi-nand",
1848                 .of_match_table = gpmi_nand_id_table,
1849         },
1850         .probe   = gpmi_nand_probe,
1851         .remove  = gpmi_nand_remove,
1852 };
1853 module_platform_driver(gpmi_nand_driver);
1854 
1855 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
1856 MODULE_DESCRIPTION("i.MX GPMI NAND Flash Controller Driver");
1857 MODULE_LICENSE("GPL");
1858 

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