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 */
38static uint8_t scan_ff_pattern[] = { 0xff };
39static 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 */
50static struct nand_ecclayout gpmi_hw_ecclayout = {
51	.eccbytes = 0,
52	.eccpos = { 0, },
53	.oobfree = { {.offset = 0, .length = 0} }
54};
55
56static const struct gpmi_devdata gpmi_devdata_imx23 = {
57	.type = IS_MX23,
58	.bch_max_ecc_strength = 20,
59	.max_chain_delay = 16,
60};
61
62static const struct gpmi_devdata gpmi_devdata_imx28 = {
63	.type = IS_MX28,
64	.bch_max_ecc_strength = 20,
65	.max_chain_delay = 16,
66};
67
68static const struct gpmi_devdata gpmi_devdata_imx6q = {
69	.type = IS_MX6Q,
70	.bch_max_ecc_strength = 40,
71	.max_chain_delay = 12,
72};
73
74static const struct gpmi_devdata gpmi_devdata_imx6sx = {
75	.type = IS_MX6SX,
76	.bch_max_ecc_strength = 62,
77	.max_chain_delay = 12,
78};
79
80static 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 */
107static 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
120static 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 */
139static 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
257static 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
367int 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
375struct 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? */
382void 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
399map_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. */
412static 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
445int 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 */
476int 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
499static 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
522static 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
542static 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
552static 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
567acquire_err:
568	release_dma_channels(this);
569	return -EINVAL;
570}
571
572static char *extra_clks_for_mx6q[GPMI_CLK_MAX] = {
573	"gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
574};
575
576static 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
620err_clock:
621	dev_dbg(this->dev, "failed in finding the clocks.\n");
622	return err;
623}
624
625static 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
650exit_clock:
651	release_dma_channels(this);
652exit_regs:
653	return ret;
654}
655
656static void release_resources(struct gpmi_nand_data *this)
657{
658	release_dma_channels(this);
659}
660
661static 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
689static 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
714map_failed:
715	*use_virt = alt_virt;
716	*use_phys = alt_phys;
717	this->direct_dma_map_ok = false;
718	return 0;
719}
720
721static 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
730static 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
739static 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	}
762map_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
774static 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
784static 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 */
803static 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
852error_alloc:
853	gpmi_free_dma_buffer(this);
854	return -ENOMEM;
855}
856
857static 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
891static 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
899static 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
912static 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
924static 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
936static 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 */
951static 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
994static 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 */
1074static 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
1162static 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);
1228exit_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 */
1298static 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
1325static int
1326gpmi_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 */
1358static 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 */
1446static 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
1523static 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
1531static 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
1539static 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
1572static 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
1598static const char  *fingerprint = "STMP";
1599static 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. */
1654static 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
1734static 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
1804static 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
1814static 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
1832static void gpmi_nand_exit(struct gpmi_nand_data *this)
1833{
1834	nand_release(&this->mtd);
1835	gpmi_free_dma_buffer(this);
1836}
1837
1838static 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
1887static 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
1963err_out:
1964	gpmi_nand_exit(this);
1965	return ret;
1966}
1967
1968static 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};
1983MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
1984
1985static 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
2023exit_nfc_init:
2024	release_resources(this);
2025exit_acquire_resources:
2026
2027	return ret;
2028}
2029
2030static 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
2039static 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};
2047module_platform_driver(gpmi_nand_driver);
2048
2049MODULE_AUTHOR("Freescale Semiconductor, Inc.");
2050MODULE_DESCRIPTION("i.MX GPMI NAND Flash Controller Driver");
2051MODULE_LICENSE("GPL");
2052