1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright �� 2004 Texas Instruments, Jian Zhang <jzhang@ti.com>
4 * Copyright �� 2004 Micron Technology Inc.
5 * Copyright �� 2004 David Brownell
6 */
7
8#include <linux/platform_device.h>
9#include <linux/dmaengine.h>
10#include <linux/dma-mapping.h>
11#include <linux/delay.h>
12#include <linux/gpio/consumer.h>
13#include <linux/module.h>
14#include <linux/interrupt.h>
15#include <linux/jiffies.h>
16#include <linux/sched.h>
17#include <linux/mtd/mtd.h>
18#include <linux/mtd/nand-ecc-sw-bch.h>
19#include <linux/mtd/rawnand.h>
20#include <linux/mtd/partitions.h>
21#include <linux/omap-dma.h>
22#include <linux/iopoll.h>
23#include <linux/slab.h>
24#include <linux/of.h>
25#include <linux/of_platform.h>
26
27#include <linux/platform_data/elm.h>
28
29#include <linux/omap-gpmc.h>
30#include <linux/platform_data/mtd-nand-omap2.h>
31
32#define	DRIVER_NAME	"omap2-nand"
33#define	OMAP_NAND_TIMEOUT_MS	5000
34
35#define NAND_Ecc_P1e		(1 << 0)
36#define NAND_Ecc_P2e		(1 << 1)
37#define NAND_Ecc_P4e		(1 << 2)
38#define NAND_Ecc_P8e		(1 << 3)
39#define NAND_Ecc_P16e		(1 << 4)
40#define NAND_Ecc_P32e		(1 << 5)
41#define NAND_Ecc_P64e		(1 << 6)
42#define NAND_Ecc_P128e		(1 << 7)
43#define NAND_Ecc_P256e		(1 << 8)
44#define NAND_Ecc_P512e		(1 << 9)
45#define NAND_Ecc_P1024e		(1 << 10)
46#define NAND_Ecc_P2048e		(1 << 11)
47
48#define NAND_Ecc_P1o		(1 << 16)
49#define NAND_Ecc_P2o		(1 << 17)
50#define NAND_Ecc_P4o		(1 << 18)
51#define NAND_Ecc_P8o		(1 << 19)
52#define NAND_Ecc_P16o		(1 << 20)
53#define NAND_Ecc_P32o		(1 << 21)
54#define NAND_Ecc_P64o		(1 << 22)
55#define NAND_Ecc_P128o		(1 << 23)
56#define NAND_Ecc_P256o		(1 << 24)
57#define NAND_Ecc_P512o		(1 << 25)
58#define NAND_Ecc_P1024o		(1 << 26)
59#define NAND_Ecc_P2048o		(1 << 27)
60
61#define TF(value)	(value ? 1 : 0)
62
63#define P2048e(a)	(TF(a & NAND_Ecc_P2048e)	<< 0)
64#define P2048o(a)	(TF(a & NAND_Ecc_P2048o)	<< 1)
65#define P1e(a)		(TF(a & NAND_Ecc_P1e)		<< 2)
66#define P1o(a)		(TF(a & NAND_Ecc_P1o)		<< 3)
67#define P2e(a)		(TF(a & NAND_Ecc_P2e)		<< 4)
68#define P2o(a)		(TF(a & NAND_Ecc_P2o)		<< 5)
69#define P4e(a)		(TF(a & NAND_Ecc_P4e)		<< 6)
70#define P4o(a)		(TF(a & NAND_Ecc_P4o)		<< 7)
71
72#define P8e(a)		(TF(a & NAND_Ecc_P8e)		<< 0)
73#define P8o(a)		(TF(a & NAND_Ecc_P8o)		<< 1)
74#define P16e(a)		(TF(a & NAND_Ecc_P16e)		<< 2)
75#define P16o(a)		(TF(a & NAND_Ecc_P16o)		<< 3)
76#define P32e(a)		(TF(a & NAND_Ecc_P32e)		<< 4)
77#define P32o(a)		(TF(a & NAND_Ecc_P32o)		<< 5)
78#define P64e(a)		(TF(a & NAND_Ecc_P64e)		<< 6)
79#define P64o(a)		(TF(a & NAND_Ecc_P64o)		<< 7)
80
81#define P128e(a)	(TF(a & NAND_Ecc_P128e)		<< 0)
82#define P128o(a)	(TF(a & NAND_Ecc_P128o)		<< 1)
83#define P256e(a)	(TF(a & NAND_Ecc_P256e)		<< 2)
84#define P256o(a)	(TF(a & NAND_Ecc_P256o)		<< 3)
85#define P512e(a)	(TF(a & NAND_Ecc_P512e)		<< 4)
86#define P512o(a)	(TF(a & NAND_Ecc_P512o)		<< 5)
87#define P1024e(a)	(TF(a & NAND_Ecc_P1024e)	<< 6)
88#define P1024o(a)	(TF(a & NAND_Ecc_P1024o)	<< 7)
89
90#define P8e_s(a)	(TF(a & NAND_Ecc_P8e)		<< 0)
91#define P8o_s(a)	(TF(a & NAND_Ecc_P8o)		<< 1)
92#define P16e_s(a)	(TF(a & NAND_Ecc_P16e)		<< 2)
93#define P16o_s(a)	(TF(a & NAND_Ecc_P16o)		<< 3)
94#define P1e_s(a)	(TF(a & NAND_Ecc_P1e)		<< 4)
95#define P1o_s(a)	(TF(a & NAND_Ecc_P1o)		<< 5)
96#define P2e_s(a)	(TF(a & NAND_Ecc_P2e)		<< 6)
97#define P2o_s(a)	(TF(a & NAND_Ecc_P2o)		<< 7)
98
99#define P4e_s(a)	(TF(a & NAND_Ecc_P4e)		<< 0)
100#define P4o_s(a)	(TF(a & NAND_Ecc_P4o)		<< 1)
101
102#define	PREFETCH_CONFIG1_CS_SHIFT	24
103#define	ECC_CONFIG_CS_SHIFT		1
104#define	CS_MASK				0x7
105#define	ENABLE_PREFETCH			(0x1 << 7)
106#define	DMA_MPU_MODE_SHIFT		2
107#define	ECCSIZE0_SHIFT			12
108#define	ECCSIZE1_SHIFT			22
109#define	ECC1RESULTSIZE			0x1
110#define	ECCCLEAR			0x100
111#define	ECC1				0x1
112#define	PREFETCH_FIFOTHRESHOLD_MAX	0x40
113#define	PREFETCH_FIFOTHRESHOLD(val)	((val) << 8)
114#define	PREFETCH_STATUS_COUNT(val)	(val & 0x00003fff)
115#define	PREFETCH_STATUS_FIFO_CNT(val)	((val >> 24) & 0x7F)
116#define	STATUS_BUFF_EMPTY		0x00000001
117
118#define SECTOR_BYTES		512
119/* 4 bit padding to make byte aligned, 56 = 52 + 4 */
120#define BCH4_BIT_PAD		4
121
122/* GPMC ecc engine settings for read */
123#define BCH_WRAPMODE_1		1	/* BCH wrap mode 1 */
124#define BCH8R_ECC_SIZE0		0x1a	/* ecc_size0 = 26 */
125#define BCH8R_ECC_SIZE1		0x2	/* ecc_size1 = 2 */
126#define BCH4R_ECC_SIZE0		0xd	/* ecc_size0 = 13 */
127#define BCH4R_ECC_SIZE1		0x3	/* ecc_size1 = 3 */
128
129/* GPMC ecc engine settings for write */
130#define BCH_WRAPMODE_6		6	/* BCH wrap mode 6 */
131#define BCH_ECC_SIZE0		0x0	/* ecc_size0 = 0, no oob protection */
132#define BCH_ECC_SIZE1		0x20	/* ecc_size1 = 32 */
133
134#define BBM_LEN			2
135
136static u_char bch16_vector[] = {0xf5, 0x24, 0x1c, 0xd0, 0x61, 0xb3, 0xf1, 0x55,
137				0x2e, 0x2c, 0x86, 0xa3, 0xed, 0x36, 0x1b, 0x78,
138				0x48, 0x76, 0xa9, 0x3b, 0x97, 0xd1, 0x7a, 0x93,
139				0x07, 0x0e};
140static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
141	0xac, 0x6b, 0xff, 0x99, 0x7b};
142static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
143
144struct omap_nand_info {
145	struct nand_chip		nand;
146	struct platform_device		*pdev;
147
148	int				gpmc_cs;
149	bool				dev_ready;
150	enum nand_io			xfer_type;
151	enum omap_ecc			ecc_opt;
152	struct device_node		*elm_of_node;
153
154	unsigned long			phys_base;
155	struct completion		comp;
156	struct dma_chan			*dma;
157	int				gpmc_irq_fifo;
158	int				gpmc_irq_count;
159	enum {
160		OMAP_NAND_IO_READ = 0,	/* read */
161		OMAP_NAND_IO_WRITE,	/* write */
162	} iomode;
163	u_char				*buf;
164	int					buf_len;
165	/* Interface to GPMC */
166	void __iomem			*fifo;
167	struct gpmc_nand_regs		reg;
168	struct gpmc_nand_ops		*ops;
169	bool				flash_bbt;
170	/* fields specific for BCHx_HW ECC scheme */
171	struct device			*elm_dev;
172	/* NAND ready gpio */
173	struct gpio_desc		*ready_gpiod;
174	unsigned int			neccpg;
175	unsigned int			nsteps_per_eccpg;
176	unsigned int			eccpg_size;
177	unsigned int			eccpg_bytes;
178	void (*data_in)(struct nand_chip *chip, void *buf,
179			unsigned int len, bool force_8bit);
180	void (*data_out)(struct nand_chip *chip,
181			 const void *buf, unsigned int len,
182			 bool force_8bit);
183};
184
185static inline struct omap_nand_info *mtd_to_omap(struct mtd_info *mtd)
186{
187	return container_of(mtd_to_nand(mtd), struct omap_nand_info, nand);
188}
189
190static void omap_nand_data_in(struct nand_chip *chip, void *buf,
191			      unsigned int len, bool force_8bit);
192
193static void omap_nand_data_out(struct nand_chip *chip,
194			       const void *buf, unsigned int len,
195			       bool force_8bit);
196
197/**
198 * omap_prefetch_enable - configures and starts prefetch transfer
199 * @cs: cs (chip select) number
200 * @fifo_th: fifo threshold to be used for read/ write
201 * @dma_mode: dma mode enable (1) or disable (0)
202 * @u32_count: number of bytes to be transferred
203 * @is_write: prefetch read(0) or write post(1) mode
204 * @info: NAND device structure containing platform data
205 */
206static int omap_prefetch_enable(int cs, int fifo_th, int dma_mode,
207	unsigned int u32_count, int is_write, struct omap_nand_info *info)
208{
209	u32 val;
210
211	if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX)
212		return -1;
213
214	if (readl(info->reg.gpmc_prefetch_control))
215		return -EBUSY;
216
217	/* Set the amount of bytes to be prefetched */
218	writel(u32_count, info->reg.gpmc_prefetch_config2);
219
220	/* Set dma/mpu mode, the prefetch read / post write and
221	 * enable the engine. Set which cs is has requested for.
222	 */
223	val = ((cs << PREFETCH_CONFIG1_CS_SHIFT) |
224		PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH |
225		(dma_mode << DMA_MPU_MODE_SHIFT) | (is_write & 0x1));
226	writel(val, info->reg.gpmc_prefetch_config1);
227
228	/*  Start the prefetch engine */
229	writel(0x1, info->reg.gpmc_prefetch_control);
230
231	return 0;
232}
233
234/*
235 * omap_prefetch_reset - disables and stops the prefetch engine
236 */
237static int omap_prefetch_reset(int cs, struct omap_nand_info *info)
238{
239	u32 config1;
240
241	/* check if the same module/cs is trying to reset */
242	config1 = readl(info->reg.gpmc_prefetch_config1);
243	if (((config1 >> PREFETCH_CONFIG1_CS_SHIFT) & CS_MASK) != cs)
244		return -EINVAL;
245
246	/* Stop the PFPW engine */
247	writel(0x0, info->reg.gpmc_prefetch_control);
248
249	/* Reset/disable the PFPW engine */
250	writel(0x0, info->reg.gpmc_prefetch_config1);
251
252	return 0;
253}
254
255/**
256 * omap_nand_data_in_pref - NAND data in using prefetch engine
257 */
258static void omap_nand_data_in_pref(struct nand_chip *chip, void *buf,
259				   unsigned int len, bool force_8bit)
260{
261	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
262	uint32_t r_count = 0;
263	int ret = 0;
264	u32 *p = (u32 *)buf;
265	unsigned int pref_len;
266
267	if (force_8bit) {
268		omap_nand_data_in(chip, buf, len, force_8bit);
269		return;
270	}
271
272	/* read 32-bit words using prefetch and remaining bytes normally */
273
274	/* configure and start prefetch transfer */
275	pref_len = len - (len & 3);
276	ret = omap_prefetch_enable(info->gpmc_cs,
277			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, pref_len, 0x0, info);
278	if (ret) {
279		/* prefetch engine is busy, use CPU copy method */
280		omap_nand_data_in(chip, buf, len, false);
281	} else {
282		do {
283			r_count = readl(info->reg.gpmc_prefetch_status);
284			r_count = PREFETCH_STATUS_FIFO_CNT(r_count);
285			r_count = r_count >> 2;
286			ioread32_rep(info->fifo, p, r_count);
287			p += r_count;
288			pref_len -= r_count << 2;
289		} while (pref_len);
290		/* disable and stop the Prefetch engine */
291		omap_prefetch_reset(info->gpmc_cs, info);
292		/* fetch any remaining bytes */
293		if (len & 3)
294			omap_nand_data_in(chip, p, len & 3, false);
295	}
296}
297
298/**
299 * omap_nand_data_out_pref - NAND data out using Write Posting engine
300 */
301static void omap_nand_data_out_pref(struct nand_chip *chip,
302				    const void *buf, unsigned int len,
303				    bool force_8bit)
304{
305	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
306	uint32_t w_count = 0;
307	int i = 0, ret = 0;
308	u16 *p = (u16 *)buf;
309	unsigned long tim, limit;
310	u32 val;
311
312	if (force_8bit) {
313		omap_nand_data_out(chip, buf, len, force_8bit);
314		return;
315	}
316
317	/* take care of subpage writes */
318	if (len % 2 != 0) {
319		writeb(*(u8 *)buf, info->fifo);
320		p = (u16 *)(buf + 1);
321		len--;
322	}
323
324	/*  configure and start prefetch transfer */
325	ret = omap_prefetch_enable(info->gpmc_cs,
326			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x1, info);
327	if (ret) {
328		/* write posting engine is busy, use CPU copy method */
329		omap_nand_data_out(chip, buf, len, false);
330	} else {
331		while (len) {
332			w_count = readl(info->reg.gpmc_prefetch_status);
333			w_count = PREFETCH_STATUS_FIFO_CNT(w_count);
334			w_count = w_count >> 1;
335			for (i = 0; (i < w_count) && len; i++, len -= 2)
336				iowrite16(*p++, info->fifo);
337		}
338		/* wait for data to flushed-out before reset the prefetch */
339		tim = 0;
340		limit = (loops_per_jiffy *
341					msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
342		do {
343			cpu_relax();
344			val = readl(info->reg.gpmc_prefetch_status);
345			val = PREFETCH_STATUS_COUNT(val);
346		} while (val && (tim++ < limit));
347
348		/* disable and stop the PFPW engine */
349		omap_prefetch_reset(info->gpmc_cs, info);
350	}
351}
352
353/*
354 * omap_nand_dma_callback: callback on the completion of dma transfer
355 * @data: pointer to completion data structure
356 */
357static void omap_nand_dma_callback(void *data)
358{
359	complete((struct completion *) data);
360}
361
362/*
363 * omap_nand_dma_transfer: configure and start dma transfer
364 * @chip: nand chip structure
365 * @addr: virtual address in RAM of source/destination
366 * @len: number of data bytes to be transferred
367 * @is_write: flag for read/write operation
368 */
369static inline int omap_nand_dma_transfer(struct nand_chip *chip,
370					 const void *addr, unsigned int len,
371					 int is_write)
372{
373	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
374	struct dma_async_tx_descriptor *tx;
375	enum dma_data_direction dir = is_write ? DMA_TO_DEVICE :
376							DMA_FROM_DEVICE;
377	struct scatterlist sg;
378	unsigned long tim, limit;
379	unsigned n;
380	int ret;
381	u32 val;
382
383	if (!virt_addr_valid(addr))
384		goto out_copy;
385
386	sg_init_one(&sg, addr, len);
387	n = dma_map_sg(info->dma->device->dev, &sg, 1, dir);
388	if (n == 0) {
389		dev_err(&info->pdev->dev,
390			"Couldn't DMA map a %d byte buffer\n", len);
391		goto out_copy;
392	}
393
394	tx = dmaengine_prep_slave_sg(info->dma, &sg, n,
395		is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
396		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
397	if (!tx)
398		goto out_copy_unmap;
399
400	tx->callback = omap_nand_dma_callback;
401	tx->callback_param = &info->comp;
402	dmaengine_submit(tx);
403
404	init_completion(&info->comp);
405
406	/* setup and start DMA using dma_addr */
407	dma_async_issue_pending(info->dma);
408
409	/*  configure and start prefetch transfer */
410	ret = omap_prefetch_enable(info->gpmc_cs,
411		PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write, info);
412	if (ret)
413		/* PFPW engine is busy, use cpu copy method */
414		goto out_copy_unmap;
415
416	wait_for_completion(&info->comp);
417	tim = 0;
418	limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
419
420	do {
421		cpu_relax();
422		val = readl(info->reg.gpmc_prefetch_status);
423		val = PREFETCH_STATUS_COUNT(val);
424	} while (val && (tim++ < limit));
425
426	/* disable and stop the PFPW engine */
427	omap_prefetch_reset(info->gpmc_cs, info);
428
429	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
430	return 0;
431
432out_copy_unmap:
433	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
434out_copy:
435	is_write == 0 ? omap_nand_data_in(chip, (void *)addr, len, false)
436		      : omap_nand_data_out(chip, addr, len, false);
437
438	return 0;
439}
440
441/**
442 * omap_nand_data_in_dma_pref - NAND data in using DMA and Prefetch
443 */
444static void omap_nand_data_in_dma_pref(struct nand_chip *chip, void *buf,
445				       unsigned int len, bool force_8bit)
446{
447	struct mtd_info *mtd = nand_to_mtd(chip);
448
449	if (force_8bit) {
450		omap_nand_data_in(chip, buf, len, force_8bit);
451		return;
452	}
453
454	if (len <= mtd->oobsize)
455		omap_nand_data_in_pref(chip, buf, len, false);
456	else
457		/* start transfer in DMA mode */
458		omap_nand_dma_transfer(chip, buf, len, 0x0);
459}
460
461/**
462 * omap_nand_data_out_dma_pref - NAND data out using DMA and write posting
463 */
464static void omap_nand_data_out_dma_pref(struct nand_chip *chip,
465					const void *buf, unsigned int len,
466					bool force_8bit)
467{
468	struct mtd_info *mtd = nand_to_mtd(chip);
469
470	if (force_8bit) {
471		omap_nand_data_out(chip, buf, len, force_8bit);
472		return;
473	}
474
475	if (len <= mtd->oobsize)
476		omap_nand_data_out_pref(chip, buf, len, false);
477	else
478		/* start transfer in DMA mode */
479		omap_nand_dma_transfer(chip, buf, len, 0x1);
480}
481
482/*
483 * omap_nand_irq - GPMC irq handler
484 * @this_irq: gpmc irq number
485 * @dev: omap_nand_info structure pointer is passed here
486 */
487static irqreturn_t omap_nand_irq(int this_irq, void *dev)
488{
489	struct omap_nand_info *info = (struct omap_nand_info *) dev;
490	u32 bytes;
491
492	bytes = readl(info->reg.gpmc_prefetch_status);
493	bytes = PREFETCH_STATUS_FIFO_CNT(bytes);
494	bytes = bytes  & 0xFFFC; /* io in multiple of 4 bytes */
495	if (info->iomode == OMAP_NAND_IO_WRITE) { /* checks for write io */
496		if (this_irq == info->gpmc_irq_count)
497			goto done;
498
499		if (info->buf_len && (info->buf_len < bytes))
500			bytes = info->buf_len;
501		else if (!info->buf_len)
502			bytes = 0;
503		iowrite32_rep(info->fifo, (u32 *)info->buf,
504			      bytes >> 2);
505		info->buf = info->buf + bytes;
506		info->buf_len -= bytes;
507
508	} else {
509		ioread32_rep(info->fifo, (u32 *)info->buf,
510			     bytes >> 2);
511		info->buf = info->buf + bytes;
512
513		if (this_irq == info->gpmc_irq_count)
514			goto done;
515	}
516
517	return IRQ_HANDLED;
518
519done:
520	complete(&info->comp);
521
522	disable_irq_nosync(info->gpmc_irq_fifo);
523	disable_irq_nosync(info->gpmc_irq_count);
524
525	return IRQ_HANDLED;
526}
527
528/*
529 * omap_nand_data_in_irq_pref - NAND data in using Prefetch and IRQ
530 */
531static void omap_nand_data_in_irq_pref(struct nand_chip *chip, void *buf,
532				       unsigned int len, bool force_8bit)
533{
534	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
535	struct mtd_info *mtd = nand_to_mtd(&info->nand);
536	int ret = 0;
537
538	if (len <= mtd->oobsize || force_8bit) {
539		omap_nand_data_in(chip, buf, len, force_8bit);
540		return;
541	}
542
543	info->iomode = OMAP_NAND_IO_READ;
544	info->buf = buf;
545	init_completion(&info->comp);
546
547	/*  configure and start prefetch transfer */
548	ret = omap_prefetch_enable(info->gpmc_cs,
549			PREFETCH_FIFOTHRESHOLD_MAX/2, 0x0, len, 0x0, info);
550	if (ret) {
551		/* PFPW engine is busy, use cpu copy method */
552		omap_nand_data_in(chip, buf, len, false);
553		return;
554	}
555
556	info->buf_len = len;
557
558	enable_irq(info->gpmc_irq_count);
559	enable_irq(info->gpmc_irq_fifo);
560
561	/* waiting for read to complete */
562	wait_for_completion(&info->comp);
563
564	/* disable and stop the PFPW engine */
565	omap_prefetch_reset(info->gpmc_cs, info);
566	return;
567}
568
569/*
570 * omap_nand_data_out_irq_pref - NAND out using write posting and IRQ
571 */
572static void omap_nand_data_out_irq_pref(struct nand_chip *chip,
573					const void *buf, unsigned int len,
574					bool force_8bit)
575{
576	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
577	struct mtd_info *mtd = nand_to_mtd(&info->nand);
578	int ret = 0;
579	unsigned long tim, limit;
580	u32 val;
581
582	if (len <= mtd->oobsize || force_8bit) {
583		omap_nand_data_out(chip, buf, len, force_8bit);
584		return;
585	}
586
587	info->iomode = OMAP_NAND_IO_WRITE;
588	info->buf = (u_char *) buf;
589	init_completion(&info->comp);
590
591	/* configure and start prefetch transfer : size=24 */
592	ret = omap_prefetch_enable(info->gpmc_cs,
593		(PREFETCH_FIFOTHRESHOLD_MAX * 3) / 8, 0x0, len, 0x1, info);
594	if (ret) {
595		/* PFPW engine is busy, use cpu copy method */
596		omap_nand_data_out(chip, buf, len, false);
597		return;
598	}
599
600	info->buf_len = len;
601
602	enable_irq(info->gpmc_irq_count);
603	enable_irq(info->gpmc_irq_fifo);
604
605	/* waiting for write to complete */
606	wait_for_completion(&info->comp);
607
608	/* wait for data to flushed-out before reset the prefetch */
609	tim = 0;
610	limit = (loops_per_jiffy *  msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
611	do {
612		val = readl(info->reg.gpmc_prefetch_status);
613		val = PREFETCH_STATUS_COUNT(val);
614		cpu_relax();
615	} while (val && (tim++ < limit));
616
617	/* disable and stop the PFPW engine */
618	omap_prefetch_reset(info->gpmc_cs, info);
619	return;
620}
621
622/**
623 * gen_true_ecc - This function will generate true ECC value
624 * @ecc_buf: buffer to store ecc code
625 *
626 * This generated true ECC value can be used when correcting
627 * data read from NAND flash memory core
628 */
629static void gen_true_ecc(u8 *ecc_buf)
630{
631	u32 tmp = ecc_buf[0] | (ecc_buf[1] << 16) |
632		((ecc_buf[2] & 0xF0) << 20) | ((ecc_buf[2] & 0x0F) << 8);
633
634	ecc_buf[0] = ~(P64o(tmp) | P64e(tmp) | P32o(tmp) | P32e(tmp) |
635			P16o(tmp) | P16e(tmp) | P8o(tmp) | P8e(tmp));
636	ecc_buf[1] = ~(P1024o(tmp) | P1024e(tmp) | P512o(tmp) | P512e(tmp) |
637			P256o(tmp) | P256e(tmp) | P128o(tmp) | P128e(tmp));
638	ecc_buf[2] = ~(P4o(tmp) | P4e(tmp) | P2o(tmp) | P2e(tmp) | P1o(tmp) |
639			P1e(tmp) | P2048o(tmp) | P2048e(tmp));
640}
641
642/**
643 * omap_compare_ecc - Detect (2 bits) and correct (1 bit) error in data
644 * @ecc_data1:  ecc code from nand spare area
645 * @ecc_data2:  ecc code from hardware register obtained from hardware ecc
646 * @page_data:  page data
647 *
648 * This function compares two ECC's and indicates if there is an error.
649 * If the error can be corrected it will be corrected to the buffer.
650 * If there is no error, %0 is returned. If there is an error but it
651 * was corrected, %1 is returned. Otherwise, %-1 is returned.
652 */
653static int omap_compare_ecc(u8 *ecc_data1,	/* read from NAND memory */
654			    u8 *ecc_data2,	/* read from register */
655			    u8 *page_data)
656{
657	uint	i;
658	u8	tmp0_bit[8], tmp1_bit[8], tmp2_bit[8];
659	u8	comp0_bit[8], comp1_bit[8], comp2_bit[8];
660	u8	ecc_bit[24];
661	u8	ecc_sum = 0;
662	u8	find_bit = 0;
663	uint	find_byte = 0;
664	int	isEccFF;
665
666	isEccFF = ((*(u32 *)ecc_data1 & 0xFFFFFF) == 0xFFFFFF);
667
668	gen_true_ecc(ecc_data1);
669	gen_true_ecc(ecc_data2);
670
671	for (i = 0; i <= 2; i++) {
672		*(ecc_data1 + i) = ~(*(ecc_data1 + i));
673		*(ecc_data2 + i) = ~(*(ecc_data2 + i));
674	}
675
676	for (i = 0; i < 8; i++) {
677		tmp0_bit[i]     = *ecc_data1 % 2;
678		*ecc_data1	= *ecc_data1 / 2;
679	}
680
681	for (i = 0; i < 8; i++) {
682		tmp1_bit[i]	 = *(ecc_data1 + 1) % 2;
683		*(ecc_data1 + 1) = *(ecc_data1 + 1) / 2;
684	}
685
686	for (i = 0; i < 8; i++) {
687		tmp2_bit[i]	 = *(ecc_data1 + 2) % 2;
688		*(ecc_data1 + 2) = *(ecc_data1 + 2) / 2;
689	}
690
691	for (i = 0; i < 8; i++) {
692		comp0_bit[i]     = *ecc_data2 % 2;
693		*ecc_data2       = *ecc_data2 / 2;
694	}
695
696	for (i = 0; i < 8; i++) {
697		comp1_bit[i]     = *(ecc_data2 + 1) % 2;
698		*(ecc_data2 + 1) = *(ecc_data2 + 1) / 2;
699	}
700
701	for (i = 0; i < 8; i++) {
702		comp2_bit[i]     = *(ecc_data2 + 2) % 2;
703		*(ecc_data2 + 2) = *(ecc_data2 + 2) / 2;
704	}
705
706	for (i = 0; i < 6; i++)
707		ecc_bit[i] = tmp2_bit[i + 2] ^ comp2_bit[i + 2];
708
709	for (i = 0; i < 8; i++)
710		ecc_bit[i + 6] = tmp0_bit[i] ^ comp0_bit[i];
711
712	for (i = 0; i < 8; i++)
713		ecc_bit[i + 14] = tmp1_bit[i] ^ comp1_bit[i];
714
715	ecc_bit[22] = tmp2_bit[0] ^ comp2_bit[0];
716	ecc_bit[23] = tmp2_bit[1] ^ comp2_bit[1];
717
718	for (i = 0; i < 24; i++)
719		ecc_sum += ecc_bit[i];
720
721	switch (ecc_sum) {
722	case 0:
723		/* Not reached because this function is not called if
724		 *  ECC values are equal
725		 */
726		return 0;
727
728	case 1:
729		/* Uncorrectable error */
730		pr_debug("ECC UNCORRECTED_ERROR 1\n");
731		return -EBADMSG;
732
733	case 11:
734		/* UN-Correctable error */
735		pr_debug("ECC UNCORRECTED_ERROR B\n");
736		return -EBADMSG;
737
738	case 12:
739		/* Correctable error */
740		find_byte = (ecc_bit[23] << 8) +
741			    (ecc_bit[21] << 7) +
742			    (ecc_bit[19] << 6) +
743			    (ecc_bit[17] << 5) +
744			    (ecc_bit[15] << 4) +
745			    (ecc_bit[13] << 3) +
746			    (ecc_bit[11] << 2) +
747			    (ecc_bit[9]  << 1) +
748			    ecc_bit[7];
749
750		find_bit = (ecc_bit[5] << 2) + (ecc_bit[3] << 1) + ecc_bit[1];
751
752		pr_debug("Correcting single bit ECC error at offset: "
753				"%d, bit: %d\n", find_byte, find_bit);
754
755		page_data[find_byte] ^= (1 << find_bit);
756
757		return 1;
758	default:
759		if (isEccFF) {
760			if (ecc_data2[0] == 0 &&
761			    ecc_data2[1] == 0 &&
762			    ecc_data2[2] == 0)
763				return 0;
764		}
765		pr_debug("UNCORRECTED_ERROR default\n");
766		return -EBADMSG;
767	}
768}
769
770/**
771 * omap_correct_data - Compares the ECC read with HW generated ECC
772 * @chip: NAND chip object
773 * @dat: page data
774 * @read_ecc: ecc read from nand flash
775 * @calc_ecc: ecc read from HW ECC registers
776 *
777 * Compares the ecc read from nand spare area with ECC registers values
778 * and if ECC's mismatched, it will call 'omap_compare_ecc' for error
779 * detection and correction. If there are no errors, %0 is returned. If
780 * there were errors and all of the errors were corrected, the number of
781 * corrected errors is returned. If uncorrectable errors exist, %-1 is
782 * returned.
783 */
784static int omap_correct_data(struct nand_chip *chip, u_char *dat,
785			     u_char *read_ecc, u_char *calc_ecc)
786{
787	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
788	int blockCnt = 0, i = 0, ret = 0;
789	int stat = 0;
790
791	/* Ex NAND_ECC_HW12_2048 */
792	if (info->nand.ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST &&
793	    info->nand.ecc.size == 2048)
794		blockCnt = 4;
795	else
796		blockCnt = 1;
797
798	for (i = 0; i < blockCnt; i++) {
799		if (memcmp(read_ecc, calc_ecc, 3) != 0) {
800			ret = omap_compare_ecc(read_ecc, calc_ecc, dat);
801			if (ret < 0)
802				return ret;
803			/* keep track of the number of corrected errors */
804			stat += ret;
805		}
806		read_ecc += 3;
807		calc_ecc += 3;
808		dat      += 512;
809	}
810	return stat;
811}
812
813/**
814 * omap_calculate_ecc - Generate non-inverted ECC bytes.
815 * @chip: NAND chip object
816 * @dat: The pointer to data on which ecc is computed
817 * @ecc_code: The ecc_code buffer
818 *
819 * Using noninverted ECC can be considered ugly since writing a blank
820 * page ie. padding will clear the ECC bytes. This is no problem as long
821 * nobody is trying to write data on the seemingly unused page. Reading
822 * an erased page will produce an ECC mismatch between generated and read
823 * ECC bytes that has to be dealt with separately.
824 */
825static int omap_calculate_ecc(struct nand_chip *chip, const u_char *dat,
826			      u_char *ecc_code)
827{
828	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
829	u32 val;
830
831	val = readl(info->reg.gpmc_ecc_config);
832	if (((val >> ECC_CONFIG_CS_SHIFT) & CS_MASK) != info->gpmc_cs)
833		return -EINVAL;
834
835	/* read ecc result */
836	val = readl(info->reg.gpmc_ecc1_result);
837	*ecc_code++ = val;          /* P128e, ..., P1e */
838	*ecc_code++ = val >> 16;    /* P128o, ..., P1o */
839	/* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
840	*ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
841
842	return 0;
843}
844
845/**
846 * omap_enable_hwecc - This function enables the hardware ecc functionality
847 * @chip: NAND chip object
848 * @mode: Read/Write mode
849 */
850static void omap_enable_hwecc(struct nand_chip *chip, int mode)
851{
852	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
853	unsigned int dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
854	u32 val;
855
856	/* clear ecc and enable bits */
857	val = ECCCLEAR | ECC1;
858	writel(val, info->reg.gpmc_ecc_control);
859
860	/* program ecc and result sizes */
861	val = ((((info->nand.ecc.size >> 1) - 1) << ECCSIZE1_SHIFT) |
862			 ECC1RESULTSIZE);
863	writel(val, info->reg.gpmc_ecc_size_config);
864
865	switch (mode) {
866	case NAND_ECC_READ:
867	case NAND_ECC_WRITE:
868		writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
869		break;
870	case NAND_ECC_READSYN:
871		writel(ECCCLEAR, info->reg.gpmc_ecc_control);
872		break;
873	default:
874		dev_info(&info->pdev->dev,
875			"error: unrecognized Mode[%d]!\n", mode);
876		break;
877	}
878
879	/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
880	val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
881	writel(val, info->reg.gpmc_ecc_config);
882}
883
884/**
885 * omap_enable_hwecc_bch - Program GPMC to perform BCH ECC calculation
886 * @chip: NAND chip object
887 * @mode: Read/Write mode
888 *
889 * When using BCH with SW correction (i.e. no ELM), sector size is set
890 * to 512 bytes and we use BCH_WRAPMODE_6 wrapping mode
891 * for both reading and writing with:
892 * eccsize0 = 0  (no additional protected byte in spare area)
893 * eccsize1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
894 */
895static void __maybe_unused omap_enable_hwecc_bch(struct nand_chip *chip,
896						 int mode)
897{
898	unsigned int bch_type;
899	unsigned int dev_width, nsectors;
900	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
901	enum omap_ecc ecc_opt = info->ecc_opt;
902	u32 val, wr_mode;
903	unsigned int ecc_size1, ecc_size0;
904
905	/* GPMC configurations for calculating ECC */
906	switch (ecc_opt) {
907	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
908		bch_type = 0;
909		nsectors = 1;
910		wr_mode	  = BCH_WRAPMODE_6;
911		ecc_size0 = BCH_ECC_SIZE0;
912		ecc_size1 = BCH_ECC_SIZE1;
913		break;
914	case OMAP_ECC_BCH4_CODE_HW:
915		bch_type = 0;
916		nsectors = chip->ecc.steps;
917		if (mode == NAND_ECC_READ) {
918			wr_mode	  = BCH_WRAPMODE_1;
919			ecc_size0 = BCH4R_ECC_SIZE0;
920			ecc_size1 = BCH4R_ECC_SIZE1;
921		} else {
922			wr_mode   = BCH_WRAPMODE_6;
923			ecc_size0 = BCH_ECC_SIZE0;
924			ecc_size1 = BCH_ECC_SIZE1;
925		}
926		break;
927	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
928		bch_type = 1;
929		nsectors = 1;
930		wr_mode	  = BCH_WRAPMODE_6;
931		ecc_size0 = BCH_ECC_SIZE0;
932		ecc_size1 = BCH_ECC_SIZE1;
933		break;
934	case OMAP_ECC_BCH8_CODE_HW:
935		bch_type = 1;
936		nsectors = chip->ecc.steps;
937		if (mode == NAND_ECC_READ) {
938			wr_mode	  = BCH_WRAPMODE_1;
939			ecc_size0 = BCH8R_ECC_SIZE0;
940			ecc_size1 = BCH8R_ECC_SIZE1;
941		} else {
942			wr_mode   = BCH_WRAPMODE_6;
943			ecc_size0 = BCH_ECC_SIZE0;
944			ecc_size1 = BCH_ECC_SIZE1;
945		}
946		break;
947	case OMAP_ECC_BCH16_CODE_HW:
948		bch_type = 0x2;
949		nsectors = chip->ecc.steps;
950		if (mode == NAND_ECC_READ) {
951			wr_mode	  = 0x01;
952			ecc_size0 = 52; /* ECC bits in nibbles per sector */
953			ecc_size1 = 0;  /* non-ECC bits in nibbles per sector */
954		} else {
955			wr_mode	  = 0x01;
956			ecc_size0 = 0;  /* extra bits in nibbles per sector */
957			ecc_size1 = 52; /* OOB bits in nibbles per sector */
958		}
959		break;
960	default:
961		return;
962	}
963
964	writel(ECC1, info->reg.gpmc_ecc_control);
965
966	/* Configure ecc size for BCH */
967	val = (ecc_size1 << ECCSIZE1_SHIFT) | (ecc_size0 << ECCSIZE0_SHIFT);
968	writel(val, info->reg.gpmc_ecc_size_config);
969
970	dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
971
972	/* BCH configuration */
973	val = ((1                        << 16) | /* enable BCH */
974	       (bch_type		 << 12) | /* BCH4/BCH8/BCH16 */
975	       (wr_mode                  <<  8) | /* wrap mode */
976	       (dev_width                <<  7) | /* bus width */
977	       (((nsectors-1) & 0x7)     <<  4) | /* number of sectors */
978	       (info->gpmc_cs            <<  1) | /* ECC CS */
979	       (0x1));                            /* enable ECC */
980
981	writel(val, info->reg.gpmc_ecc_config);
982
983	/* Clear ecc and enable bits */
984	writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
985}
986
987static u8  bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
988static u8  bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2,
989				0x97, 0x79, 0xe5, 0x24, 0xb5};
990
991/**
992 * _omap_calculate_ecc_bch - Generate ECC bytes for one sector
993 * @mtd:	MTD device structure
994 * @dat:	The pointer to data on which ecc is computed
995 * @ecc_calc:	The ecc_code buffer
996 * @i:		The sector number (for a multi sector page)
997 *
998 * Support calculating of BCH4/8/16 ECC vectors for one sector
999 * within a page. Sector number is in @i.
1000 */
1001static int _omap_calculate_ecc_bch(struct mtd_info *mtd,
1002				   const u_char *dat, u_char *ecc_calc, int i)
1003{
1004	struct omap_nand_info *info = mtd_to_omap(mtd);
1005	int eccbytes	= info->nand.ecc.bytes;
1006	struct gpmc_nand_regs	*gpmc_regs = &info->reg;
1007	u8 *ecc_code;
1008	unsigned long bch_val1, bch_val2, bch_val3, bch_val4;
1009	u32 val;
1010	int j;
1011
1012	ecc_code = ecc_calc;
1013	switch (info->ecc_opt) {
1014	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1015	case OMAP_ECC_BCH8_CODE_HW:
1016		bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1017		bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1018		bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
1019		bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
1020		*ecc_code++ = (bch_val4 & 0xFF);
1021		*ecc_code++ = ((bch_val3 >> 24) & 0xFF);
1022		*ecc_code++ = ((bch_val3 >> 16) & 0xFF);
1023		*ecc_code++ = ((bch_val3 >> 8) & 0xFF);
1024		*ecc_code++ = (bch_val3 & 0xFF);
1025		*ecc_code++ = ((bch_val2 >> 24) & 0xFF);
1026		*ecc_code++ = ((bch_val2 >> 16) & 0xFF);
1027		*ecc_code++ = ((bch_val2 >> 8) & 0xFF);
1028		*ecc_code++ = (bch_val2 & 0xFF);
1029		*ecc_code++ = ((bch_val1 >> 24) & 0xFF);
1030		*ecc_code++ = ((bch_val1 >> 16) & 0xFF);
1031		*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
1032		*ecc_code++ = (bch_val1 & 0xFF);
1033		break;
1034	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1035	case OMAP_ECC_BCH4_CODE_HW:
1036		bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1037		bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1038		*ecc_code++ = ((bch_val2 >> 12) & 0xFF);
1039		*ecc_code++ = ((bch_val2 >> 4) & 0xFF);
1040		*ecc_code++ = ((bch_val2 & 0xF) << 4) |
1041			((bch_val1 >> 28) & 0xF);
1042		*ecc_code++ = ((bch_val1 >> 20) & 0xFF);
1043		*ecc_code++ = ((bch_val1 >> 12) & 0xFF);
1044		*ecc_code++ = ((bch_val1 >> 4) & 0xFF);
1045		*ecc_code++ = ((bch_val1 & 0xF) << 4);
1046		break;
1047	case OMAP_ECC_BCH16_CODE_HW:
1048		val = readl(gpmc_regs->gpmc_bch_result6[i]);
1049		ecc_code[0]  = ((val >>  8) & 0xFF);
1050		ecc_code[1]  = ((val >>  0) & 0xFF);
1051		val = readl(gpmc_regs->gpmc_bch_result5[i]);
1052		ecc_code[2]  = ((val >> 24) & 0xFF);
1053		ecc_code[3]  = ((val >> 16) & 0xFF);
1054		ecc_code[4]  = ((val >>  8) & 0xFF);
1055		ecc_code[5]  = ((val >>  0) & 0xFF);
1056		val = readl(gpmc_regs->gpmc_bch_result4[i]);
1057		ecc_code[6]  = ((val >> 24) & 0xFF);
1058		ecc_code[7]  = ((val >> 16) & 0xFF);
1059		ecc_code[8]  = ((val >>  8) & 0xFF);
1060		ecc_code[9]  = ((val >>  0) & 0xFF);
1061		val = readl(gpmc_regs->gpmc_bch_result3[i]);
1062		ecc_code[10] = ((val >> 24) & 0xFF);
1063		ecc_code[11] = ((val >> 16) & 0xFF);
1064		ecc_code[12] = ((val >>  8) & 0xFF);
1065		ecc_code[13] = ((val >>  0) & 0xFF);
1066		val = readl(gpmc_regs->gpmc_bch_result2[i]);
1067		ecc_code[14] = ((val >> 24) & 0xFF);
1068		ecc_code[15] = ((val >> 16) & 0xFF);
1069		ecc_code[16] = ((val >>  8) & 0xFF);
1070		ecc_code[17] = ((val >>  0) & 0xFF);
1071		val = readl(gpmc_regs->gpmc_bch_result1[i]);
1072		ecc_code[18] = ((val >> 24) & 0xFF);
1073		ecc_code[19] = ((val >> 16) & 0xFF);
1074		ecc_code[20] = ((val >>  8) & 0xFF);
1075		ecc_code[21] = ((val >>  0) & 0xFF);
1076		val = readl(gpmc_regs->gpmc_bch_result0[i]);
1077		ecc_code[22] = ((val >> 24) & 0xFF);
1078		ecc_code[23] = ((val >> 16) & 0xFF);
1079		ecc_code[24] = ((val >>  8) & 0xFF);
1080		ecc_code[25] = ((val >>  0) & 0xFF);
1081		break;
1082	default:
1083		return -EINVAL;
1084	}
1085
1086	/* ECC scheme specific syndrome customizations */
1087	switch (info->ecc_opt) {
1088	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1089		/* Add constant polynomial to remainder, so that
1090		 * ECC of blank pages results in 0x0 on reading back
1091		 */
1092		for (j = 0; j < eccbytes; j++)
1093			ecc_calc[j] ^= bch4_polynomial[j];
1094		break;
1095	case OMAP_ECC_BCH4_CODE_HW:
1096		/* Set  8th ECC byte as 0x0 for ROM compatibility */
1097		ecc_calc[eccbytes - 1] = 0x0;
1098		break;
1099	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1100		/* Add constant polynomial to remainder, so that
1101		 * ECC of blank pages results in 0x0 on reading back
1102		 */
1103		for (j = 0; j < eccbytes; j++)
1104			ecc_calc[j] ^= bch8_polynomial[j];
1105		break;
1106	case OMAP_ECC_BCH8_CODE_HW:
1107		/* Set 14th ECC byte as 0x0 for ROM compatibility */
1108		ecc_calc[eccbytes - 1] = 0x0;
1109		break;
1110	case OMAP_ECC_BCH16_CODE_HW:
1111		break;
1112	default:
1113		return -EINVAL;
1114	}
1115
1116	return 0;
1117}
1118
1119/**
1120 * omap_calculate_ecc_bch_sw - ECC generator for sector for SW based correction
1121 * @chip:	NAND chip object
1122 * @dat:	The pointer to data on which ecc is computed
1123 * @ecc_calc:	Buffer storing the calculated ECC bytes
1124 *
1125 * Support calculating of BCH4/8/16 ECC vectors for one sector. This is used
1126 * when SW based correction is required as ECC is required for one sector
1127 * at a time.
1128 */
1129static int omap_calculate_ecc_bch_sw(struct nand_chip *chip,
1130				     const u_char *dat, u_char *ecc_calc)
1131{
1132	return _omap_calculate_ecc_bch(nand_to_mtd(chip), dat, ecc_calc, 0);
1133}
1134
1135/**
1136 * omap_calculate_ecc_bch_multi - Generate ECC for multiple sectors
1137 * @mtd:	MTD device structure
1138 * @dat:	The pointer to data on which ecc is computed
1139 * @ecc_calc:	Buffer storing the calculated ECC bytes
1140 *
1141 * Support calculating of BCH4/8/16 ecc vectors for the entire page in one go.
1142 */
1143static int omap_calculate_ecc_bch_multi(struct mtd_info *mtd,
1144					const u_char *dat, u_char *ecc_calc)
1145{
1146	struct omap_nand_info *info = mtd_to_omap(mtd);
1147	int eccbytes = info->nand.ecc.bytes;
1148	unsigned long nsectors;
1149	int i, ret;
1150
1151	nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
1152	for (i = 0; i < nsectors; i++) {
1153		ret = _omap_calculate_ecc_bch(mtd, dat, ecc_calc, i);
1154		if (ret)
1155			return ret;
1156
1157		ecc_calc += eccbytes;
1158	}
1159
1160	return 0;
1161}
1162
1163/**
1164 * erased_sector_bitflips - count bit flips
1165 * @data:	data sector buffer
1166 * @oob:	oob buffer
1167 * @info:	omap_nand_info
1168 *
1169 * Check the bit flips in erased page falls below correctable level.
1170 * If falls below, report the page as erased with correctable bit
1171 * flip, else report as uncorrectable page.
1172 */
1173static int erased_sector_bitflips(u_char *data, u_char *oob,
1174		struct omap_nand_info *info)
1175{
1176	int flip_bits = 0, i;
1177
1178	for (i = 0; i < info->nand.ecc.size; i++) {
1179		flip_bits += hweight8(~data[i]);
1180		if (flip_bits > info->nand.ecc.strength)
1181			return 0;
1182	}
1183
1184	for (i = 0; i < info->nand.ecc.bytes - 1; i++) {
1185		flip_bits += hweight8(~oob[i]);
1186		if (flip_bits > info->nand.ecc.strength)
1187			return 0;
1188	}
1189
1190	/*
1191	 * Bit flips falls in correctable level.
1192	 * Fill data area with 0xFF
1193	 */
1194	if (flip_bits) {
1195		memset(data, 0xFF, info->nand.ecc.size);
1196		memset(oob, 0xFF, info->nand.ecc.bytes);
1197	}
1198
1199	return flip_bits;
1200}
1201
1202/**
1203 * omap_elm_correct_data - corrects page data area in case error reported
1204 * @chip:	NAND chip object
1205 * @data:	page data
1206 * @read_ecc:	ecc read from nand flash
1207 * @calc_ecc:	ecc read from HW ECC registers
1208 *
1209 * Calculated ecc vector reported as zero in case of non-error pages.
1210 * In case of non-zero ecc vector, first filter out erased-pages, and
1211 * then process data via ELM to detect bit-flips.
1212 */
1213static int omap_elm_correct_data(struct nand_chip *chip, u_char *data,
1214				 u_char *read_ecc, u_char *calc_ecc)
1215{
1216	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
1217	struct nand_ecc_ctrl *ecc = &info->nand.ecc;
1218	int eccsteps = info->nsteps_per_eccpg;
1219	int i , j, stat = 0;
1220	int eccflag, actual_eccbytes;
1221	struct elm_errorvec err_vec[ERROR_VECTOR_MAX];
1222	u_char *ecc_vec = calc_ecc;
1223	u_char *spare_ecc = read_ecc;
1224	u_char *erased_ecc_vec;
1225	u_char *buf;
1226	int bitflip_count;
1227	bool is_error_reported = false;
1228	u32 bit_pos, byte_pos, error_max, pos;
1229	int err;
1230
1231	switch (info->ecc_opt) {
1232	case OMAP_ECC_BCH4_CODE_HW:
1233		/* omit  7th ECC byte reserved for ROM code compatibility */
1234		actual_eccbytes = ecc->bytes - 1;
1235		erased_ecc_vec = bch4_vector;
1236		break;
1237	case OMAP_ECC_BCH8_CODE_HW:
1238		/* omit 14th ECC byte reserved for ROM code compatibility */
1239		actual_eccbytes = ecc->bytes - 1;
1240		erased_ecc_vec = bch8_vector;
1241		break;
1242	case OMAP_ECC_BCH16_CODE_HW:
1243		actual_eccbytes = ecc->bytes;
1244		erased_ecc_vec = bch16_vector;
1245		break;
1246	default:
1247		dev_err(&info->pdev->dev, "invalid driver configuration\n");
1248		return -EINVAL;
1249	}
1250
1251	/* Initialize elm error vector to zero */
1252	memset(err_vec, 0, sizeof(err_vec));
1253
1254	for (i = 0; i < eccsteps ; i++) {
1255		eccflag = 0;	/* initialize eccflag */
1256
1257		/*
1258		 * Check any error reported,
1259		 * In case of error, non zero ecc reported.
1260		 */
1261		for (j = 0; j < actual_eccbytes; j++) {
1262			if (calc_ecc[j] != 0) {
1263				eccflag = 1; /* non zero ecc, error present */
1264				break;
1265			}
1266		}
1267
1268		if (eccflag == 1) {
1269			if (memcmp(calc_ecc, erased_ecc_vec,
1270						actual_eccbytes) == 0) {
1271				/*
1272				 * calc_ecc[] matches pattern for ECC(all 0xff)
1273				 * so this is definitely an erased-page
1274				 */
1275			} else {
1276				buf = &data[info->nand.ecc.size * i];
1277				/*
1278				 * count number of 0-bits in read_buf.
1279				 * This check can be removed once a similar
1280				 * check is introduced in generic NAND driver
1281				 */
1282				bitflip_count = erased_sector_bitflips(
1283						buf, read_ecc, info);
1284				if (bitflip_count) {
1285					/*
1286					 * number of 0-bits within ECC limits
1287					 * So this may be an erased-page
1288					 */
1289					stat += bitflip_count;
1290				} else {
1291					/*
1292					 * Too many 0-bits. It may be a
1293					 * - programmed-page, OR
1294					 * - erased-page with many bit-flips
1295					 * So this page requires check by ELM
1296					 */
1297					err_vec[i].error_reported = true;
1298					is_error_reported = true;
1299				}
1300			}
1301		}
1302
1303		/* Update the ecc vector */
1304		calc_ecc += ecc->bytes;
1305		read_ecc += ecc->bytes;
1306	}
1307
1308	/* Check if any error reported */
1309	if (!is_error_reported)
1310		return stat;
1311
1312	/* Decode BCH error using ELM module */
1313	elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec);
1314
1315	err = 0;
1316	for (i = 0; i < eccsteps; i++) {
1317		if (err_vec[i].error_uncorrectable) {
1318			dev_err(&info->pdev->dev,
1319				"uncorrectable bit-flips found\n");
1320			err = -EBADMSG;
1321		} else if (err_vec[i].error_reported) {
1322			for (j = 0; j < err_vec[i].error_count; j++) {
1323				switch (info->ecc_opt) {
1324				case OMAP_ECC_BCH4_CODE_HW:
1325					/* Add 4 bits to take care of padding */
1326					pos = err_vec[i].error_loc[j] +
1327						BCH4_BIT_PAD;
1328					break;
1329				case OMAP_ECC_BCH8_CODE_HW:
1330				case OMAP_ECC_BCH16_CODE_HW:
1331					pos = err_vec[i].error_loc[j];
1332					break;
1333				default:
1334					return -EINVAL;
1335				}
1336				error_max = (ecc->size + actual_eccbytes) * 8;
1337				/* Calculate bit position of error */
1338				bit_pos = pos % 8;
1339
1340				/* Calculate byte position of error */
1341				byte_pos = (error_max - pos - 1) / 8;
1342
1343				if (pos < error_max) {
1344					if (byte_pos < 512) {
1345						pr_debug("bitflip@dat[%d]=%x\n",
1346						     byte_pos, data[byte_pos]);
1347						data[byte_pos] ^= 1 << bit_pos;
1348					} else {
1349						pr_debug("bitflip@oob[%d]=%x\n",
1350							(byte_pos - 512),
1351						     spare_ecc[byte_pos - 512]);
1352						spare_ecc[byte_pos - 512] ^=
1353							1 << bit_pos;
1354					}
1355				} else {
1356					dev_err(&info->pdev->dev,
1357						"invalid bit-flip @ %d:%d\n",
1358						byte_pos, bit_pos);
1359					err = -EBADMSG;
1360				}
1361			}
1362		}
1363
1364		/* Update number of correctable errors */
1365		stat = max_t(unsigned int, stat, err_vec[i].error_count);
1366
1367		/* Update page data with sector size */
1368		data += ecc->size;
1369		spare_ecc += ecc->bytes;
1370	}
1371
1372	return (err) ? err : stat;
1373}
1374
1375/**
1376 * omap_write_page_bch - BCH ecc based write page function for entire page
1377 * @chip:		nand chip info structure
1378 * @buf:		data buffer
1379 * @oob_required:	must write chip->oob_poi to OOB
1380 * @page:		page
1381 *
1382 * Custom write page method evolved to support multi sector writing in one shot
1383 */
1384static int omap_write_page_bch(struct nand_chip *chip, const uint8_t *buf,
1385			       int oob_required, int page)
1386{
1387	struct mtd_info *mtd = nand_to_mtd(chip);
1388	struct omap_nand_info *info = mtd_to_omap(mtd);
1389	uint8_t *ecc_calc = chip->ecc.calc_buf;
1390	unsigned int eccpg;
1391	int ret;
1392
1393	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1394	if (ret)
1395		return ret;
1396
1397	for (eccpg = 0; eccpg < info->neccpg; eccpg++) {
1398		/* Enable GPMC ecc engine */
1399		chip->ecc.hwctl(chip, NAND_ECC_WRITE);
1400
1401		/* Write data */
1402		info->data_out(chip, buf + (eccpg * info->eccpg_size),
1403			       info->eccpg_size, false);
1404
1405		/* Update ecc vector from GPMC result registers */
1406		ret = omap_calculate_ecc_bch_multi(mtd,
1407						   buf + (eccpg * info->eccpg_size),
1408						   ecc_calc);
1409		if (ret)
1410			return ret;
1411
1412		ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc,
1413						 chip->oob_poi,
1414						 eccpg * info->eccpg_bytes,
1415						 info->eccpg_bytes);
1416		if (ret)
1417			return ret;
1418	}
1419
1420	/* Write ecc vector to OOB area */
1421	info->data_out(chip, chip->oob_poi, mtd->oobsize, false);
1422
1423	return nand_prog_page_end_op(chip);
1424}
1425
1426/**
1427 * omap_write_subpage_bch - BCH hardware ECC based subpage write
1428 * @chip:	nand chip info structure
1429 * @offset:	column address of subpage within the page
1430 * @data_len:	data length
1431 * @buf:	data buffer
1432 * @oob_required: must write chip->oob_poi to OOB
1433 * @page: page number to write
1434 *
1435 * OMAP optimized subpage write method.
1436 */
1437static int omap_write_subpage_bch(struct nand_chip *chip, u32 offset,
1438				  u32 data_len, const u8 *buf,
1439				  int oob_required, int page)
1440{
1441	struct mtd_info *mtd = nand_to_mtd(chip);
1442	struct omap_nand_info *info = mtd_to_omap(mtd);
1443	u8 *ecc_calc = chip->ecc.calc_buf;
1444	int ecc_size      = chip->ecc.size;
1445	int ecc_bytes     = chip->ecc.bytes;
1446	u32 start_step = offset / ecc_size;
1447	u32 end_step   = (offset + data_len - 1) / ecc_size;
1448	unsigned int eccpg;
1449	int step, ret = 0;
1450
1451	/*
1452	 * Write entire page at one go as it would be optimal
1453	 * as ECC is calculated by hardware.
1454	 * ECC is calculated for all subpages but we choose
1455	 * only what we want.
1456	 */
1457	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1458	if (ret)
1459		return ret;
1460
1461	for (eccpg = 0; eccpg < info->neccpg; eccpg++) {
1462		/* Enable GPMC ECC engine */
1463		chip->ecc.hwctl(chip, NAND_ECC_WRITE);
1464
1465		/* Write data */
1466		info->data_out(chip, buf + (eccpg * info->eccpg_size),
1467			       info->eccpg_size, false);
1468
1469		for (step = 0; step < info->nsteps_per_eccpg; step++) {
1470			unsigned int base_step = eccpg * info->nsteps_per_eccpg;
1471			const u8 *bufoffs = buf + (eccpg * info->eccpg_size);
1472
1473			/* Mask ECC of un-touched subpages with 0xFFs */
1474			if ((step + base_step) < start_step ||
1475			    (step + base_step) > end_step)
1476				memset(ecc_calc + (step * ecc_bytes), 0xff,
1477				       ecc_bytes);
1478			else
1479				ret = _omap_calculate_ecc_bch(mtd,
1480							      bufoffs + (step * ecc_size),
1481							      ecc_calc + (step * ecc_bytes),
1482							      step);
1483
1484			if (ret)
1485				return ret;
1486		}
1487
1488		/*
1489		 * Copy the calculated ECC for the whole page including the
1490		 * masked values (0xFF) corresponding to unwritten subpages.
1491		 */
1492		ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
1493						 eccpg * info->eccpg_bytes,
1494						 info->eccpg_bytes);
1495		if (ret)
1496			return ret;
1497	}
1498
1499	/* write OOB buffer to NAND device */
1500	info->data_out(chip, chip->oob_poi, mtd->oobsize, false);
1501
1502	return nand_prog_page_end_op(chip);
1503}
1504
1505/**
1506 * omap_read_page_bch - BCH ecc based page read function for entire page
1507 * @chip:		nand chip info structure
1508 * @buf:		buffer to store read data
1509 * @oob_required:	caller requires OOB data read to chip->oob_poi
1510 * @page:		page number to read
1511 *
1512 * For BCH ecc scheme, GPMC used for syndrome calculation and ELM module
1513 * used for error correction.
1514 * Custom method evolved to support ELM error correction & multi sector
1515 * reading. On reading page data area is read along with OOB data with
1516 * ecc engine enabled. ecc vector updated after read of OOB data.
1517 * For non error pages ecc vector reported as zero.
1518 */
1519static int omap_read_page_bch(struct nand_chip *chip, uint8_t *buf,
1520			      int oob_required, int page)
1521{
1522	struct mtd_info *mtd = nand_to_mtd(chip);
1523	struct omap_nand_info *info = mtd_to_omap(mtd);
1524	uint8_t *ecc_calc = chip->ecc.calc_buf;
1525	uint8_t *ecc_code = chip->ecc.code_buf;
1526	unsigned int max_bitflips = 0, eccpg;
1527	int stat, ret;
1528
1529	ret = nand_read_page_op(chip, page, 0, NULL, 0);
1530	if (ret)
1531		return ret;
1532
1533	for (eccpg = 0; eccpg < info->neccpg; eccpg++) {
1534		/* Enable GPMC ecc engine */
1535		chip->ecc.hwctl(chip, NAND_ECC_READ);
1536
1537		/* Read data */
1538		ret = nand_change_read_column_op(chip, eccpg * info->eccpg_size,
1539						 buf + (eccpg * info->eccpg_size),
1540						 info->eccpg_size, false);
1541		if (ret)
1542			return ret;
1543
1544		/* Read oob bytes */
1545		ret = nand_change_read_column_op(chip,
1546						 mtd->writesize + BBM_LEN +
1547						 (eccpg * info->eccpg_bytes),
1548						 chip->oob_poi + BBM_LEN +
1549						 (eccpg * info->eccpg_bytes),
1550						 info->eccpg_bytes, false);
1551		if (ret)
1552			return ret;
1553
1554		/* Calculate ecc bytes */
1555		ret = omap_calculate_ecc_bch_multi(mtd,
1556						   buf + (eccpg * info->eccpg_size),
1557						   ecc_calc);
1558		if (ret)
1559			return ret;
1560
1561		ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code,
1562						 chip->oob_poi,
1563						 eccpg * info->eccpg_bytes,
1564						 info->eccpg_bytes);
1565		if (ret)
1566			return ret;
1567
1568		stat = chip->ecc.correct(chip,
1569					 buf + (eccpg * info->eccpg_size),
1570					 ecc_code, ecc_calc);
1571		if (stat < 0) {
1572			mtd->ecc_stats.failed++;
1573		} else {
1574			mtd->ecc_stats.corrected += stat;
1575			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1576		}
1577	}
1578
1579	return max_bitflips;
1580}
1581
1582/**
1583 * is_elm_present - checks for presence of ELM module by scanning DT nodes
1584 * @info: NAND device structure containing platform data
1585 * @elm_node: ELM's DT node
1586 */
1587static bool is_elm_present(struct omap_nand_info *info,
1588			   struct device_node *elm_node)
1589{
1590	struct platform_device *pdev;
1591
1592	/* check whether elm-id is passed via DT */
1593	if (!elm_node) {
1594		dev_err(&info->pdev->dev, "ELM devicetree node not found\n");
1595		return false;
1596	}
1597	pdev = of_find_device_by_node(elm_node);
1598	/* check whether ELM device is registered */
1599	if (!pdev) {
1600		dev_err(&info->pdev->dev, "ELM device not found\n");
1601		return false;
1602	}
1603	/* ELM module available, now configure it */
1604	info->elm_dev = &pdev->dev;
1605	return true;
1606}
1607
1608static bool omap2_nand_ecc_check(struct omap_nand_info *info)
1609{
1610	bool ecc_needs_bch, ecc_needs_omap_bch, ecc_needs_elm;
1611
1612	switch (info->ecc_opt) {
1613	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1614	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1615		ecc_needs_omap_bch = false;
1616		ecc_needs_bch = true;
1617		ecc_needs_elm = false;
1618		break;
1619	case OMAP_ECC_BCH4_CODE_HW:
1620	case OMAP_ECC_BCH8_CODE_HW:
1621	case OMAP_ECC_BCH16_CODE_HW:
1622		ecc_needs_omap_bch = true;
1623		ecc_needs_bch = false;
1624		ecc_needs_elm = true;
1625		break;
1626	default:
1627		ecc_needs_omap_bch = false;
1628		ecc_needs_bch = false;
1629		ecc_needs_elm = false;
1630		break;
1631	}
1632
1633	if (ecc_needs_bch && !IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_BCH)) {
1634		dev_err(&info->pdev->dev,
1635			"CONFIG_MTD_NAND_ECC_SW_BCH not enabled\n");
1636		return false;
1637	}
1638	if (ecc_needs_omap_bch && !IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH)) {
1639		dev_err(&info->pdev->dev,
1640			"CONFIG_MTD_NAND_OMAP_BCH not enabled\n");
1641		return false;
1642	}
1643	if (ecc_needs_elm && !is_elm_present(info, info->elm_of_node)) {
1644		dev_err(&info->pdev->dev, "ELM not available\n");
1645		return false;
1646	}
1647
1648	return true;
1649}
1650
1651static const char * const nand_xfer_types[] = {
1652	[NAND_OMAP_PREFETCH_POLLED] = "prefetch-polled",
1653	[NAND_OMAP_POLLED] = "polled",
1654	[NAND_OMAP_PREFETCH_DMA] = "prefetch-dma",
1655	[NAND_OMAP_PREFETCH_IRQ] = "prefetch-irq",
1656};
1657
1658static int omap_get_dt_info(struct device *dev, struct omap_nand_info *info)
1659{
1660	struct device_node *child = dev->of_node;
1661	int i;
1662	const char *s;
1663	u32 cs;
1664
1665	if (of_property_read_u32(child, "reg", &cs) < 0) {
1666		dev_err(dev, "reg not found in DT\n");
1667		return -EINVAL;
1668	}
1669
1670	info->gpmc_cs = cs;
1671
1672	/* detect availability of ELM module. Won't be present pre-OMAP4 */
1673	info->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
1674	if (!info->elm_of_node) {
1675		info->elm_of_node = of_parse_phandle(child, "elm_id", 0);
1676		if (!info->elm_of_node)
1677			dev_dbg(dev, "ti,elm-id not in DT\n");
1678	}
1679
1680	/* select ecc-scheme for NAND */
1681	if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
1682		dev_err(dev, "ti,nand-ecc-opt not found\n");
1683		return -EINVAL;
1684	}
1685
1686	if (!strcmp(s, "sw")) {
1687		info->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
1688	} else if (!strcmp(s, "ham1") ||
1689		   !strcmp(s, "hw") || !strcmp(s, "hw-romcode")) {
1690		info->ecc_opt =	OMAP_ECC_HAM1_CODE_HW;
1691	} else if (!strcmp(s, "bch4")) {
1692		if (info->elm_of_node)
1693			info->ecc_opt = OMAP_ECC_BCH4_CODE_HW;
1694		else
1695			info->ecc_opt = OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
1696	} else if (!strcmp(s, "bch8")) {
1697		if (info->elm_of_node)
1698			info->ecc_opt = OMAP_ECC_BCH8_CODE_HW;
1699		else
1700			info->ecc_opt = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
1701	} else if (!strcmp(s, "bch16")) {
1702		info->ecc_opt =	OMAP_ECC_BCH16_CODE_HW;
1703	} else {
1704		dev_err(dev, "unrecognized value for ti,nand-ecc-opt\n");
1705		return -EINVAL;
1706	}
1707
1708	/* select data transfer mode */
1709	if (!of_property_read_string(child, "ti,nand-xfer-type", &s)) {
1710		for (i = 0; i < ARRAY_SIZE(nand_xfer_types); i++) {
1711			if (!strcasecmp(s, nand_xfer_types[i])) {
1712				info->xfer_type = i;
1713				return 0;
1714			}
1715		}
1716
1717		dev_err(dev, "unrecognized value for ti,nand-xfer-type\n");
1718		return -EINVAL;
1719	}
1720
1721	return 0;
1722}
1723
1724static int omap_ooblayout_ecc(struct mtd_info *mtd, int section,
1725			      struct mtd_oob_region *oobregion)
1726{
1727	struct omap_nand_info *info = mtd_to_omap(mtd);
1728	struct nand_chip *chip = &info->nand;
1729	int off = BBM_LEN;
1730
1731	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
1732	    !(chip->options & NAND_BUSWIDTH_16))
1733		off = 1;
1734
1735	if (section)
1736		return -ERANGE;
1737
1738	oobregion->offset = off;
1739	oobregion->length = chip->ecc.total;
1740
1741	return 0;
1742}
1743
1744static int omap_ooblayout_free(struct mtd_info *mtd, int section,
1745			       struct mtd_oob_region *oobregion)
1746{
1747	struct omap_nand_info *info = mtd_to_omap(mtd);
1748	struct nand_chip *chip = &info->nand;
1749	int off = BBM_LEN;
1750
1751	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
1752	    !(chip->options & NAND_BUSWIDTH_16))
1753		off = 1;
1754
1755	if (section)
1756		return -ERANGE;
1757
1758	off += chip->ecc.total;
1759	if (off >= mtd->oobsize)
1760		return -ERANGE;
1761
1762	oobregion->offset = off;
1763	oobregion->length = mtd->oobsize - off;
1764
1765	return 0;
1766}
1767
1768static const struct mtd_ooblayout_ops omap_ooblayout_ops = {
1769	.ecc = omap_ooblayout_ecc,
1770	.free = omap_ooblayout_free,
1771};
1772
1773static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section,
1774				 struct mtd_oob_region *oobregion)
1775{
1776	struct nand_device *nand = mtd_to_nanddev(mtd);
1777	unsigned int nsteps = nanddev_get_ecc_nsteps(nand);
1778	unsigned int ecc_bytes = nanddev_get_ecc_bytes_per_step(nand);
1779	int off = BBM_LEN;
1780
1781	if (section >= nsteps)
1782		return -ERANGE;
1783
1784	/*
1785	 * When SW correction is employed, one OMAP specific marker byte is
1786	 * reserved after each ECC step.
1787	 */
1788	oobregion->offset = off + (section * (ecc_bytes + 1));
1789	oobregion->length = ecc_bytes;
1790
1791	return 0;
1792}
1793
1794static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section,
1795				  struct mtd_oob_region *oobregion)
1796{
1797	struct nand_device *nand = mtd_to_nanddev(mtd);
1798	unsigned int nsteps = nanddev_get_ecc_nsteps(nand);
1799	unsigned int ecc_bytes = nanddev_get_ecc_bytes_per_step(nand);
1800	int off = BBM_LEN;
1801
1802	if (section)
1803		return -ERANGE;
1804
1805	/*
1806	 * When SW correction is employed, one OMAP specific marker byte is
1807	 * reserved after each ECC step.
1808	 */
1809	off += ((ecc_bytes + 1) * nsteps);
1810	if (off >= mtd->oobsize)
1811		return -ERANGE;
1812
1813	oobregion->offset = off;
1814	oobregion->length = mtd->oobsize - off;
1815
1816	return 0;
1817}
1818
1819static const struct mtd_ooblayout_ops omap_sw_ooblayout_ops = {
1820	.ecc = omap_sw_ooblayout_ecc,
1821	.free = omap_sw_ooblayout_free,
1822};
1823
1824static int omap_nand_attach_chip(struct nand_chip *chip)
1825{
1826	struct mtd_info *mtd = nand_to_mtd(chip);
1827	struct omap_nand_info *info = mtd_to_omap(mtd);
1828	struct device *dev = &info->pdev->dev;
1829	int min_oobbytes = BBM_LEN;
1830	int elm_bch_strength = -1;
1831	int oobbytes_per_step;
1832	dma_cap_mask_t mask;
1833	int err;
1834
1835	if (chip->bbt_options & NAND_BBT_USE_FLASH)
1836		chip->bbt_options |= NAND_BBT_NO_OOB;
1837	else
1838		chip->options |= NAND_SKIP_BBTSCAN;
1839
1840	/* Re-populate low-level callbacks based on xfer modes */
1841	switch (info->xfer_type) {
1842	case NAND_OMAP_PREFETCH_POLLED:
1843		info->data_in = omap_nand_data_in_pref;
1844		info->data_out = omap_nand_data_out_pref;
1845		break;
1846
1847	case NAND_OMAP_POLLED:
1848		/* Use nand_base defaults for {read,write}_buf */
1849		break;
1850
1851	case NAND_OMAP_PREFETCH_DMA:
1852		dma_cap_zero(mask);
1853		dma_cap_set(DMA_SLAVE, mask);
1854		info->dma = dma_request_chan(dev->parent, "rxtx");
1855
1856		if (IS_ERR(info->dma)) {
1857			dev_err(dev, "DMA engine request failed\n");
1858			return PTR_ERR(info->dma);
1859		} else {
1860			struct dma_slave_config cfg;
1861
1862			memset(&cfg, 0, sizeof(cfg));
1863			cfg.src_addr = info->phys_base;
1864			cfg.dst_addr = info->phys_base;
1865			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1866			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1867			cfg.src_maxburst = 16;
1868			cfg.dst_maxburst = 16;
1869			err = dmaengine_slave_config(info->dma, &cfg);
1870			if (err) {
1871				dev_err(dev,
1872					"DMA engine slave config failed: %d\n",
1873					err);
1874				return err;
1875			}
1876
1877			info->data_in = omap_nand_data_in_dma_pref;
1878			info->data_out = omap_nand_data_out_dma_pref;
1879		}
1880		break;
1881
1882	case NAND_OMAP_PREFETCH_IRQ:
1883		info->gpmc_irq_fifo = platform_get_irq(info->pdev, 0);
1884		if (info->gpmc_irq_fifo < 0)
1885			return info->gpmc_irq_fifo;
1886		err = devm_request_irq(dev, info->gpmc_irq_fifo,
1887				       omap_nand_irq, IRQF_SHARED,
1888				       "gpmc-nand-fifo", info);
1889		if (err) {
1890			dev_err(dev, "Requesting IRQ %d, error %d\n",
1891				info->gpmc_irq_fifo, err);
1892			info->gpmc_irq_fifo = 0;
1893			return err;
1894		}
1895
1896		info->gpmc_irq_count = platform_get_irq(info->pdev, 1);
1897		if (info->gpmc_irq_count < 0)
1898			return info->gpmc_irq_count;
1899		err = devm_request_irq(dev, info->gpmc_irq_count,
1900				       omap_nand_irq, IRQF_SHARED,
1901				       "gpmc-nand-count", info);
1902		if (err) {
1903			dev_err(dev, "Requesting IRQ %d, error %d\n",
1904				info->gpmc_irq_count, err);
1905			info->gpmc_irq_count = 0;
1906			return err;
1907		}
1908
1909		info->data_in = omap_nand_data_in_irq_pref;
1910		info->data_out = omap_nand_data_out_irq_pref;
1911		break;
1912
1913	default:
1914		dev_err(dev, "xfer_type %d not supported!\n", info->xfer_type);
1915		return -EINVAL;
1916	}
1917
1918	if (!omap2_nand_ecc_check(info))
1919		return -EINVAL;
1920
1921	/*
1922	 * Bail out earlier to let NAND_ECC_ENGINE_TYPE_SOFT code create its own
1923	 * ooblayout instead of using ours.
1924	 */
1925	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW) {
1926		chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
1927		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
1928		return 0;
1929	}
1930
1931	/* Populate MTD interface based on ECC scheme */
1932	switch (info->ecc_opt) {
1933	case OMAP_ECC_HAM1_CODE_HW:
1934		dev_info(dev, "nand: using OMAP_ECC_HAM1_CODE_HW\n");
1935		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
1936		chip->ecc.bytes		= 3;
1937		chip->ecc.size		= 512;
1938		chip->ecc.strength	= 1;
1939		chip->ecc.calculate	= omap_calculate_ecc;
1940		chip->ecc.hwctl		= omap_enable_hwecc;
1941		chip->ecc.correct	= omap_correct_data;
1942		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
1943		oobbytes_per_step	= chip->ecc.bytes;
1944
1945		if (!(chip->options & NAND_BUSWIDTH_16))
1946			min_oobbytes	= 1;
1947
1948		break;
1949
1950	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1951		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW\n");
1952		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
1953		chip->ecc.size		= 512;
1954		chip->ecc.bytes		= 7;
1955		chip->ecc.strength	= 4;
1956		chip->ecc.hwctl		= omap_enable_hwecc_bch;
1957		chip->ecc.correct	= rawnand_sw_bch_correct;
1958		chip->ecc.calculate	= omap_calculate_ecc_bch_sw;
1959		mtd_set_ooblayout(mtd, &omap_sw_ooblayout_ops);
1960		/* Reserve one byte for the OMAP marker */
1961		oobbytes_per_step	= chip->ecc.bytes + 1;
1962		/* Software BCH library is used for locating errors */
1963		err = rawnand_sw_bch_init(chip);
1964		if (err) {
1965			dev_err(dev, "Unable to use BCH library\n");
1966			return err;
1967		}
1968		break;
1969
1970	case OMAP_ECC_BCH4_CODE_HW:
1971		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW ECC scheme\n");
1972		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
1973		chip->ecc.size		= 512;
1974		/* 14th bit is kept reserved for ROM-code compatibility */
1975		chip->ecc.bytes		= 7 + 1;
1976		chip->ecc.strength	= 4;
1977		chip->ecc.hwctl		= omap_enable_hwecc_bch;
1978		chip->ecc.correct	= omap_elm_correct_data;
1979		chip->ecc.read_page	= omap_read_page_bch;
1980		chip->ecc.write_page	= omap_write_page_bch;
1981		chip->ecc.write_subpage	= omap_write_subpage_bch;
1982		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
1983		oobbytes_per_step	= chip->ecc.bytes;
1984		elm_bch_strength = BCH4_ECC;
1985		break;
1986
1987	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1988		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
1989		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
1990		chip->ecc.size		= 512;
1991		chip->ecc.bytes		= 13;
1992		chip->ecc.strength	= 8;
1993		chip->ecc.hwctl		= omap_enable_hwecc_bch;
1994		chip->ecc.correct	= rawnand_sw_bch_correct;
1995		chip->ecc.calculate	= omap_calculate_ecc_bch_sw;
1996		mtd_set_ooblayout(mtd, &omap_sw_ooblayout_ops);
1997		/* Reserve one byte for the OMAP marker */
1998		oobbytes_per_step	= chip->ecc.bytes + 1;
1999		/* Software BCH library is used for locating errors */
2000		err = rawnand_sw_bch_init(chip);
2001		if (err) {
2002			dev_err(dev, "unable to use BCH library\n");
2003			return err;
2004		}
2005		break;
2006
2007	case OMAP_ECC_BCH8_CODE_HW:
2008		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme\n");
2009		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2010		chip->ecc.size		= 512;
2011		/* 14th bit is kept reserved for ROM-code compatibility */
2012		chip->ecc.bytes		= 13 + 1;
2013		chip->ecc.strength	= 8;
2014		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2015		chip->ecc.correct	= omap_elm_correct_data;
2016		chip->ecc.read_page	= omap_read_page_bch;
2017		chip->ecc.write_page	= omap_write_page_bch;
2018		chip->ecc.write_subpage	= omap_write_subpage_bch;
2019		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2020		oobbytes_per_step	= chip->ecc.bytes;
2021		elm_bch_strength = BCH8_ECC;
2022		break;
2023
2024	case OMAP_ECC_BCH16_CODE_HW:
2025		pr_info("Using OMAP_ECC_BCH16_CODE_HW ECC scheme\n");
2026		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2027		chip->ecc.size		= 512;
2028		chip->ecc.bytes		= 26;
2029		chip->ecc.strength	= 16;
2030		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2031		chip->ecc.correct	= omap_elm_correct_data;
2032		chip->ecc.read_page	= omap_read_page_bch;
2033		chip->ecc.write_page	= omap_write_page_bch;
2034		chip->ecc.write_subpage	= omap_write_subpage_bch;
2035		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2036		oobbytes_per_step	= chip->ecc.bytes;
2037		elm_bch_strength = BCH16_ECC;
2038		break;
2039	default:
2040		dev_err(dev, "Invalid or unsupported ECC scheme\n");
2041		return -EINVAL;
2042	}
2043
2044	if (elm_bch_strength >= 0) {
2045		chip->ecc.steps = mtd->writesize / chip->ecc.size;
2046		info->neccpg = chip->ecc.steps / ERROR_VECTOR_MAX;
2047		if (info->neccpg) {
2048			info->nsteps_per_eccpg = ERROR_VECTOR_MAX;
2049		} else {
2050			info->neccpg = 1;
2051			info->nsteps_per_eccpg = chip->ecc.steps;
2052		}
2053		info->eccpg_size = info->nsteps_per_eccpg * chip->ecc.size;
2054		info->eccpg_bytes = info->nsteps_per_eccpg * chip->ecc.bytes;
2055
2056		err = elm_config(info->elm_dev, elm_bch_strength,
2057				 info->nsteps_per_eccpg, chip->ecc.size,
2058				 chip->ecc.bytes);
2059		if (err < 0)
2060			return err;
2061	}
2062
2063	/* Check if NAND device's OOB is enough to store ECC signatures */
2064	min_oobbytes += (oobbytes_per_step *
2065			 (mtd->writesize / chip->ecc.size));
2066	if (mtd->oobsize < min_oobbytes) {
2067		dev_err(dev,
2068			"Not enough OOB bytes: required = %d, available=%d\n",
2069			min_oobbytes, mtd->oobsize);
2070		return -EINVAL;
2071	}
2072
2073	return 0;
2074}
2075
2076static void omap_nand_data_in(struct nand_chip *chip, void *buf,
2077			      unsigned int len, bool force_8bit)
2078{
2079	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
2080	u32 alignment = ((uintptr_t)buf | len) & 3;
2081
2082	if (force_8bit || (alignment & 1))
2083		ioread8_rep(info->fifo, buf, len);
2084	else if (alignment & 3)
2085		ioread16_rep(info->fifo, buf, len >> 1);
2086	else
2087		ioread32_rep(info->fifo, buf, len >> 2);
2088}
2089
2090static void omap_nand_data_out(struct nand_chip *chip,
2091			       const void *buf, unsigned int len,
2092			       bool force_8bit)
2093{
2094	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
2095	u32 alignment = ((uintptr_t)buf | len) & 3;
2096
2097	if (force_8bit || (alignment & 1))
2098		iowrite8_rep(info->fifo, buf, len);
2099	else if (alignment & 3)
2100		iowrite16_rep(info->fifo, buf, len >> 1);
2101	else
2102		iowrite32_rep(info->fifo, buf, len >> 2);
2103}
2104
2105static int omap_nand_exec_instr(struct nand_chip *chip,
2106				const struct nand_op_instr *instr)
2107{
2108	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
2109	unsigned int i;
2110	int ret;
2111
2112	switch (instr->type) {
2113	case NAND_OP_CMD_INSTR:
2114		iowrite8(instr->ctx.cmd.opcode,
2115			 info->reg.gpmc_nand_command);
2116		break;
2117
2118	case NAND_OP_ADDR_INSTR:
2119		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
2120			iowrite8(instr->ctx.addr.addrs[i],
2121				 info->reg.gpmc_nand_address);
2122		}
2123		break;
2124
2125	case NAND_OP_DATA_IN_INSTR:
2126		info->data_in(chip, instr->ctx.data.buf.in,
2127			      instr->ctx.data.len,
2128			      instr->ctx.data.force_8bit);
2129		break;
2130
2131	case NAND_OP_DATA_OUT_INSTR:
2132		info->data_out(chip, instr->ctx.data.buf.out,
2133			       instr->ctx.data.len,
2134			       instr->ctx.data.force_8bit);
2135		break;
2136
2137	case NAND_OP_WAITRDY_INSTR:
2138		ret = info->ready_gpiod ?
2139			nand_gpio_waitrdy(chip, info->ready_gpiod, instr->ctx.waitrdy.timeout_ms) :
2140			nand_soft_waitrdy(chip, instr->ctx.waitrdy.timeout_ms);
2141		if (ret)
2142			return ret;
2143		break;
2144	}
2145
2146	if (instr->delay_ns)
2147		ndelay(instr->delay_ns);
2148
2149	return 0;
2150}
2151
2152static int omap_nand_exec_op(struct nand_chip *chip,
2153			     const struct nand_operation *op,
2154			     bool check_only)
2155{
2156	unsigned int i;
2157
2158	if (check_only)
2159		return 0;
2160
2161	for (i = 0; i < op->ninstrs; i++) {
2162		int ret;
2163
2164		ret = omap_nand_exec_instr(chip, &op->instrs[i]);
2165		if (ret)
2166			return ret;
2167	}
2168
2169	return 0;
2170}
2171
2172static const struct nand_controller_ops omap_nand_controller_ops = {
2173	.attach_chip = omap_nand_attach_chip,
2174	.exec_op = omap_nand_exec_op,
2175};
2176
2177/* Shared among all NAND instances to synchronize access to the ECC Engine */
2178static struct nand_controller omap_gpmc_controller;
2179static bool omap_gpmc_controller_initialized;
2180
2181static int omap_nand_probe(struct platform_device *pdev)
2182{
2183	struct omap_nand_info		*info;
2184	struct mtd_info			*mtd;
2185	struct nand_chip		*nand_chip;
2186	int				err;
2187	struct resource			*res;
2188	struct device			*dev = &pdev->dev;
2189	void __iomem *vaddr;
2190
2191	info = devm_kzalloc(&pdev->dev, sizeof(struct omap_nand_info),
2192				GFP_KERNEL);
2193	if (!info)
2194		return -ENOMEM;
2195
2196	info->pdev = pdev;
2197
2198	err = omap_get_dt_info(dev, info);
2199	if (err)
2200		return err;
2201
2202	info->ops = gpmc_omap_get_nand_ops(&info->reg, info->gpmc_cs);
2203	if (!info->ops) {
2204		dev_err(&pdev->dev, "Failed to get GPMC->NAND interface\n");
2205		return -ENODEV;
2206	}
2207
2208	nand_chip		= &info->nand;
2209	mtd			= nand_to_mtd(nand_chip);
2210	mtd->dev.parent		= &pdev->dev;
2211	nand_set_flash_node(nand_chip, dev->of_node);
2212
2213	if (!mtd->name) {
2214		mtd->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
2215					   "omap2-nand.%d", info->gpmc_cs);
2216		if (!mtd->name) {
2217			dev_err(&pdev->dev, "Failed to set MTD name\n");
2218			return -ENOMEM;
2219		}
2220	}
2221
2222	vaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2223	if (IS_ERR(vaddr))
2224		return PTR_ERR(vaddr);
2225
2226	info->fifo = vaddr;
2227	info->phys_base = res->start;
2228
2229	if (!omap_gpmc_controller_initialized) {
2230		omap_gpmc_controller.ops = &omap_nand_controller_ops;
2231		nand_controller_init(&omap_gpmc_controller);
2232		omap_gpmc_controller_initialized = true;
2233	}
2234
2235	nand_chip->controller = &omap_gpmc_controller;
2236
2237	info->ready_gpiod = devm_gpiod_get_optional(&pdev->dev, "rb",
2238						    GPIOD_IN);
2239	if (IS_ERR(info->ready_gpiod)) {
2240		dev_err(dev, "failed to get ready gpio\n");
2241		return PTR_ERR(info->ready_gpiod);
2242	}
2243
2244	if (info->flash_bbt)
2245		nand_chip->bbt_options |= NAND_BBT_USE_FLASH;
2246
2247	/* default operations */
2248	info->data_in = omap_nand_data_in;
2249	info->data_out = omap_nand_data_out;
2250
2251	err = nand_scan(nand_chip, 1);
2252	if (err)
2253		goto return_error;
2254
2255	err = mtd_device_register(mtd, NULL, 0);
2256	if (err)
2257		goto cleanup_nand;
2258
2259	platform_set_drvdata(pdev, mtd);
2260
2261	return 0;
2262
2263cleanup_nand:
2264	nand_cleanup(nand_chip);
2265
2266return_error:
2267	if (!IS_ERR_OR_NULL(info->dma))
2268		dma_release_channel(info->dma);
2269
2270	rawnand_sw_bch_cleanup(nand_chip);
2271
2272	return err;
2273}
2274
2275static void omap_nand_remove(struct platform_device *pdev)
2276{
2277	struct mtd_info *mtd = platform_get_drvdata(pdev);
2278	struct nand_chip *nand_chip = mtd_to_nand(mtd);
2279	struct omap_nand_info *info = mtd_to_omap(mtd);
2280
2281	rawnand_sw_bch_cleanup(nand_chip);
2282
2283	if (info->dma)
2284		dma_release_channel(info->dma);
2285	WARN_ON(mtd_device_unregister(mtd));
2286	nand_cleanup(nand_chip);
2287}
2288
2289/* omap_nand_ids defined in linux/platform_data/mtd-nand-omap2.h */
2290MODULE_DEVICE_TABLE(of, omap_nand_ids);
2291
2292static struct platform_driver omap_nand_driver = {
2293	.probe		= omap_nand_probe,
2294	.remove_new	= omap_nand_remove,
2295	.driver		= {
2296		.name	= DRIVER_NAME,
2297		.of_match_table = omap_nand_ids,
2298	},
2299};
2300
2301module_platform_driver(omap_nand_driver);
2302
2303MODULE_ALIAS("platform:" DRIVER_NAME);
2304MODULE_LICENSE("GPL");
2305MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");
2306