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/rawnand.h>
19#include <linux/mtd/partitions.h>
20#include <linux/omap-dma.h>
21#include <linux/io.h>
22#include <linux/slab.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25
26#include <linux/mtd/nand_bch.h>
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 BADBLOCK_MARKER_LENGTH		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	int				devsize;
152	enum omap_ecc			ecc_opt;
153	struct device_node		*elm_of_node;
154
155	unsigned long			phys_base;
156	struct completion		comp;
157	struct dma_chan			*dma;
158	int				gpmc_irq_fifo;
159	int				gpmc_irq_count;
160	enum {
161		OMAP_NAND_IO_READ = 0,	/* read */
162		OMAP_NAND_IO_WRITE,	/* write */
163	} iomode;
164	u_char				*buf;
165	int					buf_len;
166	/* Interface to GPMC */
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};
175
176static inline struct omap_nand_info *mtd_to_omap(struct mtd_info *mtd)
177{
178	return container_of(mtd_to_nand(mtd), struct omap_nand_info, nand);
179}
180
181/**
182 * omap_prefetch_enable - configures and starts prefetch transfer
183 * @cs: cs (chip select) number
184 * @fifo_th: fifo threshold to be used for read/ write
185 * @dma_mode: dma mode enable (1) or disable (0)
186 * @u32_count: number of bytes to be transferred
187 * @is_write: prefetch read(0) or write post(1) mode
188 */
189static int omap_prefetch_enable(int cs, int fifo_th, int dma_mode,
190	unsigned int u32_count, int is_write, struct omap_nand_info *info)
191{
192	u32 val;
193
194	if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX)
195		return -1;
196
197	if (readl(info->reg.gpmc_prefetch_control))
198		return -EBUSY;
199
200	/* Set the amount of bytes to be prefetched */
201	writel(u32_count, info->reg.gpmc_prefetch_config2);
202
203	/* Set dma/mpu mode, the prefetch read / post write and
204	 * enable the engine. Set which cs is has requested for.
205	 */
206	val = ((cs << PREFETCH_CONFIG1_CS_SHIFT) |
207		PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH |
208		(dma_mode << DMA_MPU_MODE_SHIFT) | (is_write & 0x1));
209	writel(val, info->reg.gpmc_prefetch_config1);
210
211	/*  Start the prefetch engine */
212	writel(0x1, info->reg.gpmc_prefetch_control);
213
214	return 0;
215}
216
217/**
218 * omap_prefetch_reset - disables and stops the prefetch engine
219 */
220static int omap_prefetch_reset(int cs, struct omap_nand_info *info)
221{
222	u32 config1;
223
224	/* check if the same module/cs is trying to reset */
225	config1 = readl(info->reg.gpmc_prefetch_config1);
226	if (((config1 >> PREFETCH_CONFIG1_CS_SHIFT) & CS_MASK) != cs)
227		return -EINVAL;
228
229	/* Stop the PFPW engine */
230	writel(0x0, info->reg.gpmc_prefetch_control);
231
232	/* Reset/disable the PFPW engine */
233	writel(0x0, info->reg.gpmc_prefetch_config1);
234
235	return 0;
236}
237
238/**
239 * omap_hwcontrol - hardware specific access to control-lines
240 * @chip: NAND chip object
241 * @cmd: command to device
242 * @ctrl:
243 * NAND_NCE: bit 0 -> don't care
244 * NAND_CLE: bit 1 -> Command Latch
245 * NAND_ALE: bit 2 -> Address Latch
246 *
247 * NOTE: boards may use different bits for these!!
248 */
249static void omap_hwcontrol(struct nand_chip *chip, int cmd, unsigned int ctrl)
250{
251	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
252
253	if (cmd != NAND_CMD_NONE) {
254		if (ctrl & NAND_CLE)
255			writeb(cmd, info->reg.gpmc_nand_command);
256
257		else if (ctrl & NAND_ALE)
258			writeb(cmd, info->reg.gpmc_nand_address);
259
260		else /* NAND_NCE */
261			writeb(cmd, info->reg.gpmc_nand_data);
262	}
263}
264
265/**
266 * omap_read_buf8 - read data from NAND controller into buffer
267 * @mtd: MTD device structure
268 * @buf: buffer to store date
269 * @len: number of bytes to read
270 */
271static void omap_read_buf8(struct mtd_info *mtd, u_char *buf, int len)
272{
273	struct nand_chip *nand = mtd_to_nand(mtd);
274
275	ioread8_rep(nand->legacy.IO_ADDR_R, buf, len);
276}
277
278/**
279 * omap_write_buf8 - write buffer to NAND controller
280 * @mtd: MTD device structure
281 * @buf: data buffer
282 * @len: number of bytes to write
283 */
284static void omap_write_buf8(struct mtd_info *mtd, const u_char *buf, int len)
285{
286	struct omap_nand_info *info = mtd_to_omap(mtd);
287	u_char *p = (u_char *)buf;
288	bool status;
289
290	while (len--) {
291		iowrite8(*p++, info->nand.legacy.IO_ADDR_W);
292		/* wait until buffer is available for write */
293		do {
294			status = info->ops->nand_writebuffer_empty();
295		} while (!status);
296	}
297}
298
299/**
300 * omap_read_buf16 - read data from NAND controller into buffer
301 * @mtd: MTD device structure
302 * @buf: buffer to store date
303 * @len: number of bytes to read
304 */
305static void omap_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
306{
307	struct nand_chip *nand = mtd_to_nand(mtd);
308
309	ioread16_rep(nand->legacy.IO_ADDR_R, buf, len / 2);
310}
311
312/**
313 * omap_write_buf16 - write buffer to NAND controller
314 * @mtd: MTD device structure
315 * @buf: data buffer
316 * @len: number of bytes to write
317 */
318static void omap_write_buf16(struct mtd_info *mtd, const u_char * buf, int len)
319{
320	struct omap_nand_info *info = mtd_to_omap(mtd);
321	u16 *p = (u16 *) buf;
322	bool status;
323	/* FIXME try bursts of writesw() or DMA ... */
324	len >>= 1;
325
326	while (len--) {
327		iowrite16(*p++, info->nand.legacy.IO_ADDR_W);
328		/* wait until buffer is available for write */
329		do {
330			status = info->ops->nand_writebuffer_empty();
331		} while (!status);
332	}
333}
334
335/**
336 * omap_read_buf_pref - read data from NAND controller into buffer
337 * @chip: NAND chip object
338 * @buf: buffer to store date
339 * @len: number of bytes to read
340 */
341static void omap_read_buf_pref(struct nand_chip *chip, u_char *buf, int len)
342{
343	struct mtd_info *mtd = nand_to_mtd(chip);
344	struct omap_nand_info *info = mtd_to_omap(mtd);
345	uint32_t r_count = 0;
346	int ret = 0;
347	u32 *p = (u32 *)buf;
348
349	/* take care of subpage reads */
350	if (len % 4) {
351		if (info->nand.options & NAND_BUSWIDTH_16)
352			omap_read_buf16(mtd, buf, len % 4);
353		else
354			omap_read_buf8(mtd, buf, len % 4);
355		p = (u32 *) (buf + len % 4);
356		len -= len % 4;
357	}
358
359	/* configure and start prefetch transfer */
360	ret = omap_prefetch_enable(info->gpmc_cs,
361			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x0, info);
362	if (ret) {
363		/* PFPW engine is busy, use cpu copy method */
364		if (info->nand.options & NAND_BUSWIDTH_16)
365			omap_read_buf16(mtd, (u_char *)p, len);
366		else
367			omap_read_buf8(mtd, (u_char *)p, len);
368	} else {
369		do {
370			r_count = readl(info->reg.gpmc_prefetch_status);
371			r_count = PREFETCH_STATUS_FIFO_CNT(r_count);
372			r_count = r_count >> 2;
373			ioread32_rep(info->nand.legacy.IO_ADDR_R, p, r_count);
374			p += r_count;
375			len -= r_count << 2;
376		} while (len);
377		/* disable and stop the PFPW engine */
378		omap_prefetch_reset(info->gpmc_cs, info);
379	}
380}
381
382/**
383 * omap_write_buf_pref - write buffer to NAND controller
384 * @chip: NAND chip object
385 * @buf: data buffer
386 * @len: number of bytes to write
387 */
388static void omap_write_buf_pref(struct nand_chip *chip, const u_char *buf,
389				int len)
390{
391	struct mtd_info *mtd = nand_to_mtd(chip);
392	struct omap_nand_info *info = mtd_to_omap(mtd);
393	uint32_t w_count = 0;
394	int i = 0, ret = 0;
395	u16 *p = (u16 *)buf;
396	unsigned long tim, limit;
397	u32 val;
398
399	/* take care of subpage writes */
400	if (len % 2 != 0) {
401		writeb(*buf, info->nand.legacy.IO_ADDR_W);
402		p = (u16 *)(buf + 1);
403		len--;
404	}
405
406	/*  configure and start prefetch transfer */
407	ret = omap_prefetch_enable(info->gpmc_cs,
408			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x1, info);
409	if (ret) {
410		/* PFPW engine is busy, use cpu copy method */
411		if (info->nand.options & NAND_BUSWIDTH_16)
412			omap_write_buf16(mtd, (u_char *)p, len);
413		else
414			omap_write_buf8(mtd, (u_char *)p, len);
415	} else {
416		while (len) {
417			w_count = readl(info->reg.gpmc_prefetch_status);
418			w_count = PREFETCH_STATUS_FIFO_CNT(w_count);
419			w_count = w_count >> 1;
420			for (i = 0; (i < w_count) && len; i++, len -= 2)
421				iowrite16(*p++, info->nand.legacy.IO_ADDR_W);
422		}
423		/* wait for data to flushed-out before reset the prefetch */
424		tim = 0;
425		limit = (loops_per_jiffy *
426					msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
427		do {
428			cpu_relax();
429			val = readl(info->reg.gpmc_prefetch_status);
430			val = PREFETCH_STATUS_COUNT(val);
431		} while (val && (tim++ < limit));
432
433		/* disable and stop the PFPW engine */
434		omap_prefetch_reset(info->gpmc_cs, info);
435	}
436}
437
438/*
439 * omap_nand_dma_callback: callback on the completion of dma transfer
440 * @data: pointer to completion data structure
441 */
442static void omap_nand_dma_callback(void *data)
443{
444	complete((struct completion *) data);
445}
446
447/*
448 * omap_nand_dma_transfer: configure and start dma transfer
449 * @mtd: MTD device structure
450 * @addr: virtual address in RAM of source/destination
451 * @len: number of data bytes to be transferred
452 * @is_write: flag for read/write operation
453 */
454static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
455					unsigned int len, int is_write)
456{
457	struct omap_nand_info *info = mtd_to_omap(mtd);
458	struct dma_async_tx_descriptor *tx;
459	enum dma_data_direction dir = is_write ? DMA_TO_DEVICE :
460							DMA_FROM_DEVICE;
461	struct scatterlist sg;
462	unsigned long tim, limit;
463	unsigned n;
464	int ret;
465	u32 val;
466
467	if (!virt_addr_valid(addr))
468		goto out_copy;
469
470	sg_init_one(&sg, addr, len);
471	n = dma_map_sg(info->dma->device->dev, &sg, 1, dir);
472	if (n == 0) {
473		dev_err(&info->pdev->dev,
474			"Couldn't DMA map a %d byte buffer\n", len);
475		goto out_copy;
476	}
477
478	tx = dmaengine_prep_slave_sg(info->dma, &sg, n,
479		is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
480		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
481	if (!tx)
482		goto out_copy_unmap;
483
484	tx->callback = omap_nand_dma_callback;
485	tx->callback_param = &info->comp;
486	dmaengine_submit(tx);
487
488	init_completion(&info->comp);
489
490	/* setup and start DMA using dma_addr */
491	dma_async_issue_pending(info->dma);
492
493	/*  configure and start prefetch transfer */
494	ret = omap_prefetch_enable(info->gpmc_cs,
495		PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write, info);
496	if (ret)
497		/* PFPW engine is busy, use cpu copy method */
498		goto out_copy_unmap;
499
500	wait_for_completion(&info->comp);
501	tim = 0;
502	limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
503
504	do {
505		cpu_relax();
506		val = readl(info->reg.gpmc_prefetch_status);
507		val = PREFETCH_STATUS_COUNT(val);
508	} while (val && (tim++ < limit));
509
510	/* disable and stop the PFPW engine */
511	omap_prefetch_reset(info->gpmc_cs, info);
512
513	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
514	return 0;
515
516out_copy_unmap:
517	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
518out_copy:
519	if (info->nand.options & NAND_BUSWIDTH_16)
520		is_write == 0 ? omap_read_buf16(mtd, (u_char *) addr, len)
521			: omap_write_buf16(mtd, (u_char *) addr, len);
522	else
523		is_write == 0 ? omap_read_buf8(mtd, (u_char *) addr, len)
524			: omap_write_buf8(mtd, (u_char *) addr, len);
525	return 0;
526}
527
528/**
529 * omap_read_buf_dma_pref - read data from NAND controller into buffer
530 * @chip: NAND chip object
531 * @buf: buffer to store date
532 * @len: number of bytes to read
533 */
534static void omap_read_buf_dma_pref(struct nand_chip *chip, u_char *buf,
535				   int len)
536{
537	struct mtd_info *mtd = nand_to_mtd(chip);
538
539	if (len <= mtd->oobsize)
540		omap_read_buf_pref(chip, buf, len);
541	else
542		/* start transfer in DMA mode */
543		omap_nand_dma_transfer(mtd, buf, len, 0x0);
544}
545
546/**
547 * omap_write_buf_dma_pref - write buffer to NAND controller
548 * @chip: NAND chip object
549 * @buf: data buffer
550 * @len: number of bytes to write
551 */
552static void omap_write_buf_dma_pref(struct nand_chip *chip, const u_char *buf,
553				    int len)
554{
555	struct mtd_info *mtd = nand_to_mtd(chip);
556
557	if (len <= mtd->oobsize)
558		omap_write_buf_pref(chip, buf, len);
559	else
560		/* start transfer in DMA mode */
561		omap_nand_dma_transfer(mtd, (u_char *)buf, len, 0x1);
562}
563
564/*
565 * omap_nand_irq - GPMC irq handler
566 * @this_irq: gpmc irq number
567 * @dev: omap_nand_info structure pointer is passed here
568 */
569static irqreturn_t omap_nand_irq(int this_irq, void *dev)
570{
571	struct omap_nand_info *info = (struct omap_nand_info *) dev;
572	u32 bytes;
573
574	bytes = readl(info->reg.gpmc_prefetch_status);
575	bytes = PREFETCH_STATUS_FIFO_CNT(bytes);
576	bytes = bytes  & 0xFFFC; /* io in multiple of 4 bytes */
577	if (info->iomode == OMAP_NAND_IO_WRITE) { /* checks for write io */
578		if (this_irq == info->gpmc_irq_count)
579			goto done;
580
581		if (info->buf_len && (info->buf_len < bytes))
582			bytes = info->buf_len;
583		else if (!info->buf_len)
584			bytes = 0;
585		iowrite32_rep(info->nand.legacy.IO_ADDR_W, (u32 *)info->buf,
586			      bytes >> 2);
587		info->buf = info->buf + bytes;
588		info->buf_len -= bytes;
589
590	} else {
591		ioread32_rep(info->nand.legacy.IO_ADDR_R, (u32 *)info->buf,
592			     bytes >> 2);
593		info->buf = info->buf + bytes;
594
595		if (this_irq == info->gpmc_irq_count)
596			goto done;
597	}
598
599	return IRQ_HANDLED;
600
601done:
602	complete(&info->comp);
603
604	disable_irq_nosync(info->gpmc_irq_fifo);
605	disable_irq_nosync(info->gpmc_irq_count);
606
607	return IRQ_HANDLED;
608}
609
610/*
611 * omap_read_buf_irq_pref - read data from NAND controller into buffer
612 * @chip: NAND chip object
613 * @buf: buffer to store date
614 * @len: number of bytes to read
615 */
616static void omap_read_buf_irq_pref(struct nand_chip *chip, u_char *buf,
617				   int len)
618{
619	struct mtd_info *mtd = nand_to_mtd(chip);
620	struct omap_nand_info *info = mtd_to_omap(mtd);
621	int ret = 0;
622
623	if (len <= mtd->oobsize) {
624		omap_read_buf_pref(chip, buf, len);
625		return;
626	}
627
628	info->iomode = OMAP_NAND_IO_READ;
629	info->buf = buf;
630	init_completion(&info->comp);
631
632	/*  configure and start prefetch transfer */
633	ret = omap_prefetch_enable(info->gpmc_cs,
634			PREFETCH_FIFOTHRESHOLD_MAX/2, 0x0, len, 0x0, info);
635	if (ret)
636		/* PFPW engine is busy, use cpu copy method */
637		goto out_copy;
638
639	info->buf_len = len;
640
641	enable_irq(info->gpmc_irq_count);
642	enable_irq(info->gpmc_irq_fifo);
643
644	/* waiting for read to complete */
645	wait_for_completion(&info->comp);
646
647	/* disable and stop the PFPW engine */
648	omap_prefetch_reset(info->gpmc_cs, info);
649	return;
650
651out_copy:
652	if (info->nand.options & NAND_BUSWIDTH_16)
653		omap_read_buf16(mtd, buf, len);
654	else
655		omap_read_buf8(mtd, buf, len);
656}
657
658/*
659 * omap_write_buf_irq_pref - write buffer to NAND controller
660 * @chip: NAND chip object
661 * @buf: data buffer
662 * @len: number of bytes to write
663 */
664static void omap_write_buf_irq_pref(struct nand_chip *chip, const u_char *buf,
665				    int len)
666{
667	struct mtd_info *mtd = nand_to_mtd(chip);
668	struct omap_nand_info *info = mtd_to_omap(mtd);
669	int ret = 0;
670	unsigned long tim, limit;
671	u32 val;
672
673	if (len <= mtd->oobsize) {
674		omap_write_buf_pref(chip, buf, len);
675		return;
676	}
677
678	info->iomode = OMAP_NAND_IO_WRITE;
679	info->buf = (u_char *) buf;
680	init_completion(&info->comp);
681
682	/* configure and start prefetch transfer : size=24 */
683	ret = omap_prefetch_enable(info->gpmc_cs,
684		(PREFETCH_FIFOTHRESHOLD_MAX * 3) / 8, 0x0, len, 0x1, info);
685	if (ret)
686		/* PFPW engine is busy, use cpu copy method */
687		goto out_copy;
688
689	info->buf_len = len;
690
691	enable_irq(info->gpmc_irq_count);
692	enable_irq(info->gpmc_irq_fifo);
693
694	/* waiting for write to complete */
695	wait_for_completion(&info->comp);
696
697	/* wait for data to flushed-out before reset the prefetch */
698	tim = 0;
699	limit = (loops_per_jiffy *  msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
700	do {
701		val = readl(info->reg.gpmc_prefetch_status);
702		val = PREFETCH_STATUS_COUNT(val);
703		cpu_relax();
704	} while (val && (tim++ < limit));
705
706	/* disable and stop the PFPW engine */
707	omap_prefetch_reset(info->gpmc_cs, info);
708	return;
709
710out_copy:
711	if (info->nand.options & NAND_BUSWIDTH_16)
712		omap_write_buf16(mtd, buf, len);
713	else
714		omap_write_buf8(mtd, buf, len);
715}
716
717/**
718 * gen_true_ecc - This function will generate true ECC value
719 * @ecc_buf: buffer to store ecc code
720 *
721 * This generated true ECC value can be used when correcting
722 * data read from NAND flash memory core
723 */
724static void gen_true_ecc(u8 *ecc_buf)
725{
726	u32 tmp = ecc_buf[0] | (ecc_buf[1] << 16) |
727		((ecc_buf[2] & 0xF0) << 20) | ((ecc_buf[2] & 0x0F) << 8);
728
729	ecc_buf[0] = ~(P64o(tmp) | P64e(tmp) | P32o(tmp) | P32e(tmp) |
730			P16o(tmp) | P16e(tmp) | P8o(tmp) | P8e(tmp));
731	ecc_buf[1] = ~(P1024o(tmp) | P1024e(tmp) | P512o(tmp) | P512e(tmp) |
732			P256o(tmp) | P256e(tmp) | P128o(tmp) | P128e(tmp));
733	ecc_buf[2] = ~(P4o(tmp) | P4e(tmp) | P2o(tmp) | P2e(tmp) | P1o(tmp) |
734			P1e(tmp) | P2048o(tmp) | P2048e(tmp));
735}
736
737/**
738 * omap_compare_ecc - Detect (2 bits) and correct (1 bit) error in data
739 * @ecc_data1:  ecc code from nand spare area
740 * @ecc_data2:  ecc code from hardware register obtained from hardware ecc
741 * @page_data:  page data
742 *
743 * This function compares two ECC's and indicates if there is an error.
744 * If the error can be corrected it will be corrected to the buffer.
745 * If there is no error, %0 is returned. If there is an error but it
746 * was corrected, %1 is returned. Otherwise, %-1 is returned.
747 */
748static int omap_compare_ecc(u8 *ecc_data1,	/* read from NAND memory */
749			    u8 *ecc_data2,	/* read from register */
750			    u8 *page_data)
751{
752	uint	i;
753	u8	tmp0_bit[8], tmp1_bit[8], tmp2_bit[8];
754	u8	comp0_bit[8], comp1_bit[8], comp2_bit[8];
755	u8	ecc_bit[24];
756	u8	ecc_sum = 0;
757	u8	find_bit = 0;
758	uint	find_byte = 0;
759	int	isEccFF;
760
761	isEccFF = ((*(u32 *)ecc_data1 & 0xFFFFFF) == 0xFFFFFF);
762
763	gen_true_ecc(ecc_data1);
764	gen_true_ecc(ecc_data2);
765
766	for (i = 0; i <= 2; i++) {
767		*(ecc_data1 + i) = ~(*(ecc_data1 + i));
768		*(ecc_data2 + i) = ~(*(ecc_data2 + i));
769	}
770
771	for (i = 0; i < 8; i++) {
772		tmp0_bit[i]     = *ecc_data1 % 2;
773		*ecc_data1	= *ecc_data1 / 2;
774	}
775
776	for (i = 0; i < 8; i++) {
777		tmp1_bit[i]	 = *(ecc_data1 + 1) % 2;
778		*(ecc_data1 + 1) = *(ecc_data1 + 1) / 2;
779	}
780
781	for (i = 0; i < 8; i++) {
782		tmp2_bit[i]	 = *(ecc_data1 + 2) % 2;
783		*(ecc_data1 + 2) = *(ecc_data1 + 2) / 2;
784	}
785
786	for (i = 0; i < 8; i++) {
787		comp0_bit[i]     = *ecc_data2 % 2;
788		*ecc_data2       = *ecc_data2 / 2;
789	}
790
791	for (i = 0; i < 8; i++) {
792		comp1_bit[i]     = *(ecc_data2 + 1) % 2;
793		*(ecc_data2 + 1) = *(ecc_data2 + 1) / 2;
794	}
795
796	for (i = 0; i < 8; i++) {
797		comp2_bit[i]     = *(ecc_data2 + 2) % 2;
798		*(ecc_data2 + 2) = *(ecc_data2 + 2) / 2;
799	}
800
801	for (i = 0; i < 6; i++)
802		ecc_bit[i] = tmp2_bit[i + 2] ^ comp2_bit[i + 2];
803
804	for (i = 0; i < 8; i++)
805		ecc_bit[i + 6] = tmp0_bit[i] ^ comp0_bit[i];
806
807	for (i = 0; i < 8; i++)
808		ecc_bit[i + 14] = tmp1_bit[i] ^ comp1_bit[i];
809
810	ecc_bit[22] = tmp2_bit[0] ^ comp2_bit[0];
811	ecc_bit[23] = tmp2_bit[1] ^ comp2_bit[1];
812
813	for (i = 0; i < 24; i++)
814		ecc_sum += ecc_bit[i];
815
816	switch (ecc_sum) {
817	case 0:
818		/* Not reached because this function is not called if
819		 *  ECC values are equal
820		 */
821		return 0;
822
823	case 1:
824		/* Uncorrectable error */
825		pr_debug("ECC UNCORRECTED_ERROR 1\n");
826		return -EBADMSG;
827
828	case 11:
829		/* UN-Correctable error */
830		pr_debug("ECC UNCORRECTED_ERROR B\n");
831		return -EBADMSG;
832
833	case 12:
834		/* Correctable error */
835		find_byte = (ecc_bit[23] << 8) +
836			    (ecc_bit[21] << 7) +
837			    (ecc_bit[19] << 6) +
838			    (ecc_bit[17] << 5) +
839			    (ecc_bit[15] << 4) +
840			    (ecc_bit[13] << 3) +
841			    (ecc_bit[11] << 2) +
842			    (ecc_bit[9]  << 1) +
843			    ecc_bit[7];
844
845		find_bit = (ecc_bit[5] << 2) + (ecc_bit[3] << 1) + ecc_bit[1];
846
847		pr_debug("Correcting single bit ECC error at offset: "
848				"%d, bit: %d\n", find_byte, find_bit);
849
850		page_data[find_byte] ^= (1 << find_bit);
851
852		return 1;
853	default:
854		if (isEccFF) {
855			if (ecc_data2[0] == 0 &&
856			    ecc_data2[1] == 0 &&
857			    ecc_data2[2] == 0)
858				return 0;
859		}
860		pr_debug("UNCORRECTED_ERROR default\n");
861		return -EBADMSG;
862	}
863}
864
865/**
866 * omap_correct_data - Compares the ECC read with HW generated ECC
867 * @chip: NAND chip object
868 * @dat: page data
869 * @read_ecc: ecc read from nand flash
870 * @calc_ecc: ecc read from HW ECC registers
871 *
872 * Compares the ecc read from nand spare area with ECC registers values
873 * and if ECC's mismatched, it will call 'omap_compare_ecc' for error
874 * detection and correction. If there are no errors, %0 is returned. If
875 * there were errors and all of the errors were corrected, the number of
876 * corrected errors is returned. If uncorrectable errors exist, %-1 is
877 * returned.
878 */
879static int omap_correct_data(struct nand_chip *chip, u_char *dat,
880			     u_char *read_ecc, u_char *calc_ecc)
881{
882	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
883	int blockCnt = 0, i = 0, ret = 0;
884	int stat = 0;
885
886	/* Ex NAND_ECC_HW12_2048 */
887	if (info->nand.ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST &&
888	    info->nand.ecc.size == 2048)
889		blockCnt = 4;
890	else
891		blockCnt = 1;
892
893	for (i = 0; i < blockCnt; i++) {
894		if (memcmp(read_ecc, calc_ecc, 3) != 0) {
895			ret = omap_compare_ecc(read_ecc, calc_ecc, dat);
896			if (ret < 0)
897				return ret;
898			/* keep track of the number of corrected errors */
899			stat += ret;
900		}
901		read_ecc += 3;
902		calc_ecc += 3;
903		dat      += 512;
904	}
905	return stat;
906}
907
908/**
909 * omap_calcuate_ecc - Generate non-inverted ECC bytes.
910 * @chip: NAND chip object
911 * @dat: The pointer to data on which ecc is computed
912 * @ecc_code: The ecc_code buffer
913 *
914 * Using noninverted ECC can be considered ugly since writing a blank
915 * page ie. padding will clear the ECC bytes. This is no problem as long
916 * nobody is trying to write data on the seemingly unused page. Reading
917 * an erased page will produce an ECC mismatch between generated and read
918 * ECC bytes that has to be dealt with separately.
919 */
920static int omap_calculate_ecc(struct nand_chip *chip, const u_char *dat,
921			      u_char *ecc_code)
922{
923	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
924	u32 val;
925
926	val = readl(info->reg.gpmc_ecc_config);
927	if (((val >> ECC_CONFIG_CS_SHIFT) & CS_MASK) != info->gpmc_cs)
928		return -EINVAL;
929
930	/* read ecc result */
931	val = readl(info->reg.gpmc_ecc1_result);
932	*ecc_code++ = val;          /* P128e, ..., P1e */
933	*ecc_code++ = val >> 16;    /* P128o, ..., P1o */
934	/* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
935	*ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
936
937	return 0;
938}
939
940/**
941 * omap_enable_hwecc - This function enables the hardware ecc functionality
942 * @mtd: MTD device structure
943 * @mode: Read/Write mode
944 */
945static void omap_enable_hwecc(struct nand_chip *chip, int mode)
946{
947	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
948	unsigned int dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
949	u32 val;
950
951	/* clear ecc and enable bits */
952	val = ECCCLEAR | ECC1;
953	writel(val, info->reg.gpmc_ecc_control);
954
955	/* program ecc and result sizes */
956	val = ((((info->nand.ecc.size >> 1) - 1) << ECCSIZE1_SHIFT) |
957			 ECC1RESULTSIZE);
958	writel(val, info->reg.gpmc_ecc_size_config);
959
960	switch (mode) {
961	case NAND_ECC_READ:
962	case NAND_ECC_WRITE:
963		writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
964		break;
965	case NAND_ECC_READSYN:
966		writel(ECCCLEAR, info->reg.gpmc_ecc_control);
967		break;
968	default:
969		dev_info(&info->pdev->dev,
970			"error: unrecognized Mode[%d]!\n", mode);
971		break;
972	}
973
974	/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
975	val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
976	writel(val, info->reg.gpmc_ecc_config);
977}
978
979/**
980 * omap_wait - wait until the command is done
981 * @this: NAND Chip structure
982 *
983 * Wait function is called during Program and erase operations and
984 * the way it is called from MTD layer, we should wait till the NAND
985 * chip is ready after the programming/erase operation has completed.
986 *
987 * Erase can take up to 400ms and program up to 20ms according to
988 * general NAND and SmartMedia specs
989 */
990static int omap_wait(struct nand_chip *this)
991{
992	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(this));
993	unsigned long timeo = jiffies;
994	int status;
995
996	timeo += msecs_to_jiffies(400);
997
998	writeb(NAND_CMD_STATUS & 0xFF, info->reg.gpmc_nand_command);
999	while (time_before(jiffies, timeo)) {
1000		status = readb(info->reg.gpmc_nand_data);
1001		if (status & NAND_STATUS_READY)
1002			break;
1003		cond_resched();
1004	}
1005
1006	status = readb(info->reg.gpmc_nand_data);
1007	return status;
1008}
1009
1010/**
1011 * omap_dev_ready - checks the NAND Ready GPIO line
1012 * @mtd: MTD device structure
1013 *
1014 * Returns true if ready and false if busy.
1015 */
1016static int omap_dev_ready(struct nand_chip *chip)
1017{
1018	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
1019
1020	return gpiod_get_value(info->ready_gpiod);
1021}
1022
1023/**
1024 * omap_enable_hwecc_bch - Program GPMC to perform BCH ECC calculation
1025 * @mtd: MTD device structure
1026 * @mode: Read/Write mode
1027 *
1028 * When using BCH with SW correction (i.e. no ELM), sector size is set
1029 * to 512 bytes and we use BCH_WRAPMODE_6 wrapping mode
1030 * for both reading and writing with:
1031 * eccsize0 = 0  (no additional protected byte in spare area)
1032 * eccsize1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
1033 */
1034static void __maybe_unused omap_enable_hwecc_bch(struct nand_chip *chip,
1035						 int mode)
1036{
1037	unsigned int bch_type;
1038	unsigned int dev_width, nsectors;
1039	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
1040	enum omap_ecc ecc_opt = info->ecc_opt;
1041	u32 val, wr_mode;
1042	unsigned int ecc_size1, ecc_size0;
1043
1044	/* GPMC configurations for calculating ECC */
1045	switch (ecc_opt) {
1046	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1047		bch_type = 0;
1048		nsectors = 1;
1049		wr_mode	  = BCH_WRAPMODE_6;
1050		ecc_size0 = BCH_ECC_SIZE0;
1051		ecc_size1 = BCH_ECC_SIZE1;
1052		break;
1053	case OMAP_ECC_BCH4_CODE_HW:
1054		bch_type = 0;
1055		nsectors = chip->ecc.steps;
1056		if (mode == NAND_ECC_READ) {
1057			wr_mode	  = BCH_WRAPMODE_1;
1058			ecc_size0 = BCH4R_ECC_SIZE0;
1059			ecc_size1 = BCH4R_ECC_SIZE1;
1060		} else {
1061			wr_mode   = BCH_WRAPMODE_6;
1062			ecc_size0 = BCH_ECC_SIZE0;
1063			ecc_size1 = BCH_ECC_SIZE1;
1064		}
1065		break;
1066	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1067		bch_type = 1;
1068		nsectors = 1;
1069		wr_mode	  = BCH_WRAPMODE_6;
1070		ecc_size0 = BCH_ECC_SIZE0;
1071		ecc_size1 = BCH_ECC_SIZE1;
1072		break;
1073	case OMAP_ECC_BCH8_CODE_HW:
1074		bch_type = 1;
1075		nsectors = chip->ecc.steps;
1076		if (mode == NAND_ECC_READ) {
1077			wr_mode	  = BCH_WRAPMODE_1;
1078			ecc_size0 = BCH8R_ECC_SIZE0;
1079			ecc_size1 = BCH8R_ECC_SIZE1;
1080		} else {
1081			wr_mode   = BCH_WRAPMODE_6;
1082			ecc_size0 = BCH_ECC_SIZE0;
1083			ecc_size1 = BCH_ECC_SIZE1;
1084		}
1085		break;
1086	case OMAP_ECC_BCH16_CODE_HW:
1087		bch_type = 0x2;
1088		nsectors = chip->ecc.steps;
1089		if (mode == NAND_ECC_READ) {
1090			wr_mode	  = 0x01;
1091			ecc_size0 = 52; /* ECC bits in nibbles per sector */
1092			ecc_size1 = 0;  /* non-ECC bits in nibbles per sector */
1093		} else {
1094			wr_mode	  = 0x01;
1095			ecc_size0 = 0;  /* extra bits in nibbles per sector */
1096			ecc_size1 = 52; /* OOB bits in nibbles per sector */
1097		}
1098		break;
1099	default:
1100		return;
1101	}
1102
1103	writel(ECC1, info->reg.gpmc_ecc_control);
1104
1105	/* Configure ecc size for BCH */
1106	val = (ecc_size1 << ECCSIZE1_SHIFT) | (ecc_size0 << ECCSIZE0_SHIFT);
1107	writel(val, info->reg.gpmc_ecc_size_config);
1108
1109	dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
1110
1111	/* BCH configuration */
1112	val = ((1                        << 16) | /* enable BCH */
1113	       (bch_type		 << 12) | /* BCH4/BCH8/BCH16 */
1114	       (wr_mode                  <<  8) | /* wrap mode */
1115	       (dev_width                <<  7) | /* bus width */
1116	       (((nsectors-1) & 0x7)     <<  4) | /* number of sectors */
1117	       (info->gpmc_cs            <<  1) | /* ECC CS */
1118	       (0x1));                            /* enable ECC */
1119
1120	writel(val, info->reg.gpmc_ecc_config);
1121
1122	/* Clear ecc and enable bits */
1123	writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
1124}
1125
1126static u8  bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
1127static u8  bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2,
1128				0x97, 0x79, 0xe5, 0x24, 0xb5};
1129
1130/**
1131 * _omap_calculate_ecc_bch - Generate ECC bytes for one sector
1132 * @mtd:	MTD device structure
1133 * @dat:	The pointer to data on which ecc is computed
1134 * @ecc_code:	The ecc_code buffer
1135 * @i:		The sector number (for a multi sector page)
1136 *
1137 * Support calculating of BCH4/8/16 ECC vectors for one sector
1138 * within a page. Sector number is in @i.
1139 */
1140static int _omap_calculate_ecc_bch(struct mtd_info *mtd,
1141				   const u_char *dat, u_char *ecc_calc, int i)
1142{
1143	struct omap_nand_info *info = mtd_to_omap(mtd);
1144	int eccbytes	= info->nand.ecc.bytes;
1145	struct gpmc_nand_regs	*gpmc_regs = &info->reg;
1146	u8 *ecc_code;
1147	unsigned long bch_val1, bch_val2, bch_val3, bch_val4;
1148	u32 val;
1149	int j;
1150
1151	ecc_code = ecc_calc;
1152	switch (info->ecc_opt) {
1153	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1154	case OMAP_ECC_BCH8_CODE_HW:
1155		bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1156		bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1157		bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
1158		bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
1159		*ecc_code++ = (bch_val4 & 0xFF);
1160		*ecc_code++ = ((bch_val3 >> 24) & 0xFF);
1161		*ecc_code++ = ((bch_val3 >> 16) & 0xFF);
1162		*ecc_code++ = ((bch_val3 >> 8) & 0xFF);
1163		*ecc_code++ = (bch_val3 & 0xFF);
1164		*ecc_code++ = ((bch_val2 >> 24) & 0xFF);
1165		*ecc_code++ = ((bch_val2 >> 16) & 0xFF);
1166		*ecc_code++ = ((bch_val2 >> 8) & 0xFF);
1167		*ecc_code++ = (bch_val2 & 0xFF);
1168		*ecc_code++ = ((bch_val1 >> 24) & 0xFF);
1169		*ecc_code++ = ((bch_val1 >> 16) & 0xFF);
1170		*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
1171		*ecc_code++ = (bch_val1 & 0xFF);
1172		break;
1173	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1174	case OMAP_ECC_BCH4_CODE_HW:
1175		bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1176		bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1177		*ecc_code++ = ((bch_val2 >> 12) & 0xFF);
1178		*ecc_code++ = ((bch_val2 >> 4) & 0xFF);
1179		*ecc_code++ = ((bch_val2 & 0xF) << 4) |
1180			((bch_val1 >> 28) & 0xF);
1181		*ecc_code++ = ((bch_val1 >> 20) & 0xFF);
1182		*ecc_code++ = ((bch_val1 >> 12) & 0xFF);
1183		*ecc_code++ = ((bch_val1 >> 4) & 0xFF);
1184		*ecc_code++ = ((bch_val1 & 0xF) << 4);
1185		break;
1186	case OMAP_ECC_BCH16_CODE_HW:
1187		val = readl(gpmc_regs->gpmc_bch_result6[i]);
1188		ecc_code[0]  = ((val >>  8) & 0xFF);
1189		ecc_code[1]  = ((val >>  0) & 0xFF);
1190		val = readl(gpmc_regs->gpmc_bch_result5[i]);
1191		ecc_code[2]  = ((val >> 24) & 0xFF);
1192		ecc_code[3]  = ((val >> 16) & 0xFF);
1193		ecc_code[4]  = ((val >>  8) & 0xFF);
1194		ecc_code[5]  = ((val >>  0) & 0xFF);
1195		val = readl(gpmc_regs->gpmc_bch_result4[i]);
1196		ecc_code[6]  = ((val >> 24) & 0xFF);
1197		ecc_code[7]  = ((val >> 16) & 0xFF);
1198		ecc_code[8]  = ((val >>  8) & 0xFF);
1199		ecc_code[9]  = ((val >>  0) & 0xFF);
1200		val = readl(gpmc_regs->gpmc_bch_result3[i]);
1201		ecc_code[10] = ((val >> 24) & 0xFF);
1202		ecc_code[11] = ((val >> 16) & 0xFF);
1203		ecc_code[12] = ((val >>  8) & 0xFF);
1204		ecc_code[13] = ((val >>  0) & 0xFF);
1205		val = readl(gpmc_regs->gpmc_bch_result2[i]);
1206		ecc_code[14] = ((val >> 24) & 0xFF);
1207		ecc_code[15] = ((val >> 16) & 0xFF);
1208		ecc_code[16] = ((val >>  8) & 0xFF);
1209		ecc_code[17] = ((val >>  0) & 0xFF);
1210		val = readl(gpmc_regs->gpmc_bch_result1[i]);
1211		ecc_code[18] = ((val >> 24) & 0xFF);
1212		ecc_code[19] = ((val >> 16) & 0xFF);
1213		ecc_code[20] = ((val >>  8) & 0xFF);
1214		ecc_code[21] = ((val >>  0) & 0xFF);
1215		val = readl(gpmc_regs->gpmc_bch_result0[i]);
1216		ecc_code[22] = ((val >> 24) & 0xFF);
1217		ecc_code[23] = ((val >> 16) & 0xFF);
1218		ecc_code[24] = ((val >>  8) & 0xFF);
1219		ecc_code[25] = ((val >>  0) & 0xFF);
1220		break;
1221	default:
1222		return -EINVAL;
1223	}
1224
1225	/* ECC scheme specific syndrome customizations */
1226	switch (info->ecc_opt) {
1227	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1228		/* Add constant polynomial to remainder, so that
1229		 * ECC of blank pages results in 0x0 on reading back
1230		 */
1231		for (j = 0; j < eccbytes; j++)
1232			ecc_calc[j] ^= bch4_polynomial[j];
1233		break;
1234	case OMAP_ECC_BCH4_CODE_HW:
1235		/* Set  8th ECC byte as 0x0 for ROM compatibility */
1236		ecc_calc[eccbytes - 1] = 0x0;
1237		break;
1238	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1239		/* Add constant polynomial to remainder, so that
1240		 * ECC of blank pages results in 0x0 on reading back
1241		 */
1242		for (j = 0; j < eccbytes; j++)
1243			ecc_calc[j] ^= bch8_polynomial[j];
1244		break;
1245	case OMAP_ECC_BCH8_CODE_HW:
1246		/* Set 14th ECC byte as 0x0 for ROM compatibility */
1247		ecc_calc[eccbytes - 1] = 0x0;
1248		break;
1249	case OMAP_ECC_BCH16_CODE_HW:
1250		break;
1251	default:
1252		return -EINVAL;
1253	}
1254
1255	return 0;
1256}
1257
1258/**
1259 * omap_calculate_ecc_bch_sw - ECC generator for sector for SW based correction
1260 * @chip:	NAND chip object
1261 * @dat:	The pointer to data on which ecc is computed
1262 * @ecc_code:	The ecc_code buffer
1263 *
1264 * Support calculating of BCH4/8/16 ECC vectors for one sector. This is used
1265 * when SW based correction is required as ECC is required for one sector
1266 * at a time.
1267 */
1268static int omap_calculate_ecc_bch_sw(struct nand_chip *chip,
1269				     const u_char *dat, u_char *ecc_calc)
1270{
1271	return _omap_calculate_ecc_bch(nand_to_mtd(chip), dat, ecc_calc, 0);
1272}
1273
1274/**
1275 * omap_calculate_ecc_bch_multi - Generate ECC for multiple sectors
1276 * @mtd:	MTD device structure
1277 * @dat:	The pointer to data on which ecc is computed
1278 * @ecc_code:	The ecc_code buffer
1279 *
1280 * Support calculating of BCH4/8/16 ecc vectors for the entire page in one go.
1281 */
1282static int omap_calculate_ecc_bch_multi(struct mtd_info *mtd,
1283					const u_char *dat, u_char *ecc_calc)
1284{
1285	struct omap_nand_info *info = mtd_to_omap(mtd);
1286	int eccbytes = info->nand.ecc.bytes;
1287	unsigned long nsectors;
1288	int i, ret;
1289
1290	nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
1291	for (i = 0; i < nsectors; i++) {
1292		ret = _omap_calculate_ecc_bch(mtd, dat, ecc_calc, i);
1293		if (ret)
1294			return ret;
1295
1296		ecc_calc += eccbytes;
1297	}
1298
1299	return 0;
1300}
1301
1302/**
1303 * erased_sector_bitflips - count bit flips
1304 * @data:	data sector buffer
1305 * @oob:	oob buffer
1306 * @info:	omap_nand_info
1307 *
1308 * Check the bit flips in erased page falls below correctable level.
1309 * If falls below, report the page as erased with correctable bit
1310 * flip, else report as uncorrectable page.
1311 */
1312static int erased_sector_bitflips(u_char *data, u_char *oob,
1313		struct omap_nand_info *info)
1314{
1315	int flip_bits = 0, i;
1316
1317	for (i = 0; i < info->nand.ecc.size; i++) {
1318		flip_bits += hweight8(~data[i]);
1319		if (flip_bits > info->nand.ecc.strength)
1320			return 0;
1321	}
1322
1323	for (i = 0; i < info->nand.ecc.bytes - 1; i++) {
1324		flip_bits += hweight8(~oob[i]);
1325		if (flip_bits > info->nand.ecc.strength)
1326			return 0;
1327	}
1328
1329	/*
1330	 * Bit flips falls in correctable level.
1331	 * Fill data area with 0xFF
1332	 */
1333	if (flip_bits) {
1334		memset(data, 0xFF, info->nand.ecc.size);
1335		memset(oob, 0xFF, info->nand.ecc.bytes);
1336	}
1337
1338	return flip_bits;
1339}
1340
1341/**
1342 * omap_elm_correct_data - corrects page data area in case error reported
1343 * @chip:	NAND chip object
1344 * @data:	page data
1345 * @read_ecc:	ecc read from nand flash
1346 * @calc_ecc:	ecc read from HW ECC registers
1347 *
1348 * Calculated ecc vector reported as zero in case of non-error pages.
1349 * In case of non-zero ecc vector, first filter out erased-pages, and
1350 * then process data via ELM to detect bit-flips.
1351 */
1352static int omap_elm_correct_data(struct nand_chip *chip, u_char *data,
1353				 u_char *read_ecc, u_char *calc_ecc)
1354{
1355	struct omap_nand_info *info = mtd_to_omap(nand_to_mtd(chip));
1356	struct nand_ecc_ctrl *ecc = &info->nand.ecc;
1357	int eccsteps = info->nand.ecc.steps;
1358	int i , j, stat = 0;
1359	int eccflag, actual_eccbytes;
1360	struct elm_errorvec err_vec[ERROR_VECTOR_MAX];
1361	u_char *ecc_vec = calc_ecc;
1362	u_char *spare_ecc = read_ecc;
1363	u_char *erased_ecc_vec;
1364	u_char *buf;
1365	int bitflip_count;
1366	bool is_error_reported = false;
1367	u32 bit_pos, byte_pos, error_max, pos;
1368	int err;
1369
1370	switch (info->ecc_opt) {
1371	case OMAP_ECC_BCH4_CODE_HW:
1372		/* omit  7th ECC byte reserved for ROM code compatibility */
1373		actual_eccbytes = ecc->bytes - 1;
1374		erased_ecc_vec = bch4_vector;
1375		break;
1376	case OMAP_ECC_BCH8_CODE_HW:
1377		/* omit 14th ECC byte reserved for ROM code compatibility */
1378		actual_eccbytes = ecc->bytes - 1;
1379		erased_ecc_vec = bch8_vector;
1380		break;
1381	case OMAP_ECC_BCH16_CODE_HW:
1382		actual_eccbytes = ecc->bytes;
1383		erased_ecc_vec = bch16_vector;
1384		break;
1385	default:
1386		dev_err(&info->pdev->dev, "invalid driver configuration\n");
1387		return -EINVAL;
1388	}
1389
1390	/* Initialize elm error vector to zero */
1391	memset(err_vec, 0, sizeof(err_vec));
1392
1393	for (i = 0; i < eccsteps ; i++) {
1394		eccflag = 0;	/* initialize eccflag */
1395
1396		/*
1397		 * Check any error reported,
1398		 * In case of error, non zero ecc reported.
1399		 */
1400		for (j = 0; j < actual_eccbytes; j++) {
1401			if (calc_ecc[j] != 0) {
1402				eccflag = 1; /* non zero ecc, error present */
1403				break;
1404			}
1405		}
1406
1407		if (eccflag == 1) {
1408			if (memcmp(calc_ecc, erased_ecc_vec,
1409						actual_eccbytes) == 0) {
1410				/*
1411				 * calc_ecc[] matches pattern for ECC(all 0xff)
1412				 * so this is definitely an erased-page
1413				 */
1414			} else {
1415				buf = &data[info->nand.ecc.size * i];
1416				/*
1417				 * count number of 0-bits in read_buf.
1418				 * This check can be removed once a similar
1419				 * check is introduced in generic NAND driver
1420				 */
1421				bitflip_count = erased_sector_bitflips(
1422						buf, read_ecc, info);
1423				if (bitflip_count) {
1424					/*
1425					 * number of 0-bits within ECC limits
1426					 * So this may be an erased-page
1427					 */
1428					stat += bitflip_count;
1429				} else {
1430					/*
1431					 * Too many 0-bits. It may be a
1432					 * - programmed-page, OR
1433					 * - erased-page with many bit-flips
1434					 * So this page requires check by ELM
1435					 */
1436					err_vec[i].error_reported = true;
1437					is_error_reported = true;
1438				}
1439			}
1440		}
1441
1442		/* Update the ecc vector */
1443		calc_ecc += ecc->bytes;
1444		read_ecc += ecc->bytes;
1445	}
1446
1447	/* Check if any error reported */
1448	if (!is_error_reported)
1449		return stat;
1450
1451	/* Decode BCH error using ELM module */
1452	elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec);
1453
1454	err = 0;
1455	for (i = 0; i < eccsteps; i++) {
1456		if (err_vec[i].error_uncorrectable) {
1457			dev_err(&info->pdev->dev,
1458				"uncorrectable bit-flips found\n");
1459			err = -EBADMSG;
1460		} else if (err_vec[i].error_reported) {
1461			for (j = 0; j < err_vec[i].error_count; j++) {
1462				switch (info->ecc_opt) {
1463				case OMAP_ECC_BCH4_CODE_HW:
1464					/* Add 4 bits to take care of padding */
1465					pos = err_vec[i].error_loc[j] +
1466						BCH4_BIT_PAD;
1467					break;
1468				case OMAP_ECC_BCH8_CODE_HW:
1469				case OMAP_ECC_BCH16_CODE_HW:
1470					pos = err_vec[i].error_loc[j];
1471					break;
1472				default:
1473					return -EINVAL;
1474				}
1475				error_max = (ecc->size + actual_eccbytes) * 8;
1476				/* Calculate bit position of error */
1477				bit_pos = pos % 8;
1478
1479				/* Calculate byte position of error */
1480				byte_pos = (error_max - pos - 1) / 8;
1481
1482				if (pos < error_max) {
1483					if (byte_pos < 512) {
1484						pr_debug("bitflip@dat[%d]=%x\n",
1485						     byte_pos, data[byte_pos]);
1486						data[byte_pos] ^= 1 << bit_pos;
1487					} else {
1488						pr_debug("bitflip@oob[%d]=%x\n",
1489							(byte_pos - 512),
1490						     spare_ecc[byte_pos - 512]);
1491						spare_ecc[byte_pos - 512] ^=
1492							1 << bit_pos;
1493					}
1494				} else {
1495					dev_err(&info->pdev->dev,
1496						"invalid bit-flip @ %d:%d\n",
1497						byte_pos, bit_pos);
1498					err = -EBADMSG;
1499				}
1500			}
1501		}
1502
1503		/* Update number of correctable errors */
1504		stat = max_t(unsigned int, stat, err_vec[i].error_count);
1505
1506		/* Update page data with sector size */
1507		data += ecc->size;
1508		spare_ecc += ecc->bytes;
1509	}
1510
1511	return (err) ? err : stat;
1512}
1513
1514/**
1515 * omap_write_page_bch - BCH ecc based write page function for entire page
1516 * @chip:		nand chip info structure
1517 * @buf:		data buffer
1518 * @oob_required:	must write chip->oob_poi to OOB
1519 * @page:		page
1520 *
1521 * Custom write page method evolved to support multi sector writing in one shot
1522 */
1523static int omap_write_page_bch(struct nand_chip *chip, const uint8_t *buf,
1524			       int oob_required, int page)
1525{
1526	struct mtd_info *mtd = nand_to_mtd(chip);
1527	int ret;
1528	uint8_t *ecc_calc = chip->ecc.calc_buf;
1529
1530	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1531
1532	/* Enable GPMC ecc engine */
1533	chip->ecc.hwctl(chip, NAND_ECC_WRITE);
1534
1535	/* Write data */
1536	chip->legacy.write_buf(chip, buf, mtd->writesize);
1537
1538	/* Update ecc vector from GPMC result registers */
1539	omap_calculate_ecc_bch_multi(mtd, buf, &ecc_calc[0]);
1540
1541	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
1542					 chip->ecc.total);
1543	if (ret)
1544		return ret;
1545
1546	/* Write ecc vector to OOB area */
1547	chip->legacy.write_buf(chip, chip->oob_poi, mtd->oobsize);
1548
1549	return nand_prog_page_end_op(chip);
1550}
1551
1552/**
1553 * omap_write_subpage_bch - BCH hardware ECC based subpage write
1554 * @chip:	nand chip info structure
1555 * @offset:	column address of subpage within the page
1556 * @data_len:	data length
1557 * @buf:	data buffer
1558 * @oob_required: must write chip->oob_poi to OOB
1559 * @page: page number to write
1560 *
1561 * OMAP optimized subpage write method.
1562 */
1563static int omap_write_subpage_bch(struct nand_chip *chip, u32 offset,
1564				  u32 data_len, const u8 *buf,
1565				  int oob_required, int page)
1566{
1567	struct mtd_info *mtd = nand_to_mtd(chip);
1568	u8 *ecc_calc = chip->ecc.calc_buf;
1569	int ecc_size      = chip->ecc.size;
1570	int ecc_bytes     = chip->ecc.bytes;
1571	int ecc_steps     = chip->ecc.steps;
1572	u32 start_step = offset / ecc_size;
1573	u32 end_step   = (offset + data_len - 1) / ecc_size;
1574	int step, ret = 0;
1575
1576	/*
1577	 * Write entire page at one go as it would be optimal
1578	 * as ECC is calculated by hardware.
1579	 * ECC is calculated for all subpages but we choose
1580	 * only what we want.
1581	 */
1582	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1583
1584	/* Enable GPMC ECC engine */
1585	chip->ecc.hwctl(chip, NAND_ECC_WRITE);
1586
1587	/* Write data */
1588	chip->legacy.write_buf(chip, buf, mtd->writesize);
1589
1590	for (step = 0; step < ecc_steps; step++) {
1591		/* mask ECC of un-touched subpages by padding 0xFF */
1592		if (step < start_step || step > end_step)
1593			memset(ecc_calc, 0xff, ecc_bytes);
1594		else
1595			ret = _omap_calculate_ecc_bch(mtd, buf, ecc_calc, step);
1596
1597		if (ret)
1598			return ret;
1599
1600		buf += ecc_size;
1601		ecc_calc += ecc_bytes;
1602	}
1603
1604	/* copy calculated ECC for whole page to chip->buffer->oob */
1605	/* this include masked-value(0xFF) for unwritten subpages */
1606	ecc_calc = chip->ecc.calc_buf;
1607	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
1608					 chip->ecc.total);
1609	if (ret)
1610		return ret;
1611
1612	/* write OOB buffer to NAND device */
1613	chip->legacy.write_buf(chip, chip->oob_poi, mtd->oobsize);
1614
1615	return nand_prog_page_end_op(chip);
1616}
1617
1618/**
1619 * omap_read_page_bch - BCH ecc based page read function for entire page
1620 * @chip:		nand chip info structure
1621 * @buf:		buffer to store read data
1622 * @oob_required:	caller requires OOB data read to chip->oob_poi
1623 * @page:		page number to read
1624 *
1625 * For BCH ecc scheme, GPMC used for syndrome calculation and ELM module
1626 * used for error correction.
1627 * Custom method evolved to support ELM error correction & multi sector
1628 * reading. On reading page data area is read along with OOB data with
1629 * ecc engine enabled. ecc vector updated after read of OOB data.
1630 * For non error pages ecc vector reported as zero.
1631 */
1632static int omap_read_page_bch(struct nand_chip *chip, uint8_t *buf,
1633			      int oob_required, int page)
1634{
1635	struct mtd_info *mtd = nand_to_mtd(chip);
1636	uint8_t *ecc_calc = chip->ecc.calc_buf;
1637	uint8_t *ecc_code = chip->ecc.code_buf;
1638	int stat, ret;
1639	unsigned int max_bitflips = 0;
1640
1641	nand_read_page_op(chip, page, 0, NULL, 0);
1642
1643	/* Enable GPMC ecc engine */
1644	chip->ecc.hwctl(chip, NAND_ECC_READ);
1645
1646	/* Read data */
1647	chip->legacy.read_buf(chip, buf, mtd->writesize);
1648
1649	/* Read oob bytes */
1650	nand_change_read_column_op(chip,
1651				   mtd->writesize + BADBLOCK_MARKER_LENGTH,
1652				   chip->oob_poi + BADBLOCK_MARKER_LENGTH,
1653				   chip->ecc.total, false);
1654
1655	/* Calculate ecc bytes */
1656	omap_calculate_ecc_bch_multi(mtd, buf, ecc_calc);
1657
1658	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
1659					 chip->ecc.total);
1660	if (ret)
1661		return ret;
1662
1663	stat = chip->ecc.correct(chip, buf, ecc_code, ecc_calc);
1664
1665	if (stat < 0) {
1666		mtd->ecc_stats.failed++;
1667	} else {
1668		mtd->ecc_stats.corrected += stat;
1669		max_bitflips = max_t(unsigned int, max_bitflips, stat);
1670	}
1671
1672	return max_bitflips;
1673}
1674
1675/**
1676 * is_elm_present - checks for presence of ELM module by scanning DT nodes
1677 * @omap_nand_info: NAND device structure containing platform data
1678 */
1679static bool is_elm_present(struct omap_nand_info *info,
1680			   struct device_node *elm_node)
1681{
1682	struct platform_device *pdev;
1683
1684	/* check whether elm-id is passed via DT */
1685	if (!elm_node) {
1686		dev_err(&info->pdev->dev, "ELM devicetree node not found\n");
1687		return false;
1688	}
1689	pdev = of_find_device_by_node(elm_node);
1690	/* check whether ELM device is registered */
1691	if (!pdev) {
1692		dev_err(&info->pdev->dev, "ELM device not found\n");
1693		return false;
1694	}
1695	/* ELM module available, now configure it */
1696	info->elm_dev = &pdev->dev;
1697	return true;
1698}
1699
1700static bool omap2_nand_ecc_check(struct omap_nand_info *info)
1701{
1702	bool ecc_needs_bch, ecc_needs_omap_bch, ecc_needs_elm;
1703
1704	switch (info->ecc_opt) {
1705	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1706	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1707		ecc_needs_omap_bch = false;
1708		ecc_needs_bch = true;
1709		ecc_needs_elm = false;
1710		break;
1711	case OMAP_ECC_BCH4_CODE_HW:
1712	case OMAP_ECC_BCH8_CODE_HW:
1713	case OMAP_ECC_BCH16_CODE_HW:
1714		ecc_needs_omap_bch = true;
1715		ecc_needs_bch = false;
1716		ecc_needs_elm = true;
1717		break;
1718	default:
1719		ecc_needs_omap_bch = false;
1720		ecc_needs_bch = false;
1721		ecc_needs_elm = false;
1722		break;
1723	}
1724
1725	if (ecc_needs_bch && !IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_BCH)) {
1726		dev_err(&info->pdev->dev,
1727			"CONFIG_MTD_NAND_ECC_SW_BCH not enabled\n");
1728		return false;
1729	}
1730	if (ecc_needs_omap_bch && !IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH)) {
1731		dev_err(&info->pdev->dev,
1732			"CONFIG_MTD_NAND_OMAP_BCH not enabled\n");
1733		return false;
1734	}
1735	if (ecc_needs_elm && !is_elm_present(info, info->elm_of_node)) {
1736		dev_err(&info->pdev->dev, "ELM not available\n");
1737		return false;
1738	}
1739
1740	return true;
1741}
1742
1743static const char * const nand_xfer_types[] = {
1744	[NAND_OMAP_PREFETCH_POLLED] = "prefetch-polled",
1745	[NAND_OMAP_POLLED] = "polled",
1746	[NAND_OMAP_PREFETCH_DMA] = "prefetch-dma",
1747	[NAND_OMAP_PREFETCH_IRQ] = "prefetch-irq",
1748};
1749
1750static int omap_get_dt_info(struct device *dev, struct omap_nand_info *info)
1751{
1752	struct device_node *child = dev->of_node;
1753	int i;
1754	const char *s;
1755	u32 cs;
1756
1757	if (of_property_read_u32(child, "reg", &cs) < 0) {
1758		dev_err(dev, "reg not found in DT\n");
1759		return -EINVAL;
1760	}
1761
1762	info->gpmc_cs = cs;
1763
1764	/* detect availability of ELM module. Won't be present pre-OMAP4 */
1765	info->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
1766	if (!info->elm_of_node) {
1767		info->elm_of_node = of_parse_phandle(child, "elm_id", 0);
1768		if (!info->elm_of_node)
1769			dev_dbg(dev, "ti,elm-id not in DT\n");
1770	}
1771
1772	/* select ecc-scheme for NAND */
1773	if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
1774		dev_err(dev, "ti,nand-ecc-opt not found\n");
1775		return -EINVAL;
1776	}
1777
1778	if (!strcmp(s, "sw")) {
1779		info->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
1780	} else if (!strcmp(s, "ham1") ||
1781		   !strcmp(s, "hw") || !strcmp(s, "hw-romcode")) {
1782		info->ecc_opt =	OMAP_ECC_HAM1_CODE_HW;
1783	} else if (!strcmp(s, "bch4")) {
1784		if (info->elm_of_node)
1785			info->ecc_opt = OMAP_ECC_BCH4_CODE_HW;
1786		else
1787			info->ecc_opt = OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
1788	} else if (!strcmp(s, "bch8")) {
1789		if (info->elm_of_node)
1790			info->ecc_opt = OMAP_ECC_BCH8_CODE_HW;
1791		else
1792			info->ecc_opt = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
1793	} else if (!strcmp(s, "bch16")) {
1794		info->ecc_opt =	OMAP_ECC_BCH16_CODE_HW;
1795	} else {
1796		dev_err(dev, "unrecognized value for ti,nand-ecc-opt\n");
1797		return -EINVAL;
1798	}
1799
1800	/* select data transfer mode */
1801	if (!of_property_read_string(child, "ti,nand-xfer-type", &s)) {
1802		for (i = 0; i < ARRAY_SIZE(nand_xfer_types); i++) {
1803			if (!strcasecmp(s, nand_xfer_types[i])) {
1804				info->xfer_type = i;
1805				return 0;
1806			}
1807		}
1808
1809		dev_err(dev, "unrecognized value for ti,nand-xfer-type\n");
1810		return -EINVAL;
1811	}
1812
1813	return 0;
1814}
1815
1816static int omap_ooblayout_ecc(struct mtd_info *mtd, int section,
1817			      struct mtd_oob_region *oobregion)
1818{
1819	struct omap_nand_info *info = mtd_to_omap(mtd);
1820	struct nand_chip *chip = &info->nand;
1821	int off = BADBLOCK_MARKER_LENGTH;
1822
1823	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
1824	    !(chip->options & NAND_BUSWIDTH_16))
1825		off = 1;
1826
1827	if (section)
1828		return -ERANGE;
1829
1830	oobregion->offset = off;
1831	oobregion->length = chip->ecc.total;
1832
1833	return 0;
1834}
1835
1836static int omap_ooblayout_free(struct mtd_info *mtd, int section,
1837			       struct mtd_oob_region *oobregion)
1838{
1839	struct omap_nand_info *info = mtd_to_omap(mtd);
1840	struct nand_chip *chip = &info->nand;
1841	int off = BADBLOCK_MARKER_LENGTH;
1842
1843	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
1844	    !(chip->options & NAND_BUSWIDTH_16))
1845		off = 1;
1846
1847	if (section)
1848		return -ERANGE;
1849
1850	off += chip->ecc.total;
1851	if (off >= mtd->oobsize)
1852		return -ERANGE;
1853
1854	oobregion->offset = off;
1855	oobregion->length = mtd->oobsize - off;
1856
1857	return 0;
1858}
1859
1860static const struct mtd_ooblayout_ops omap_ooblayout_ops = {
1861	.ecc = omap_ooblayout_ecc,
1862	.free = omap_ooblayout_free,
1863};
1864
1865static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section,
1866				 struct mtd_oob_region *oobregion)
1867{
1868	struct nand_chip *chip = mtd_to_nand(mtd);
1869	int off = BADBLOCK_MARKER_LENGTH;
1870
1871	if (section >= chip->ecc.steps)
1872		return -ERANGE;
1873
1874	/*
1875	 * When SW correction is employed, one OMAP specific marker byte is
1876	 * reserved after each ECC step.
1877	 */
1878	oobregion->offset = off + (section * (chip->ecc.bytes + 1));
1879	oobregion->length = chip->ecc.bytes;
1880
1881	return 0;
1882}
1883
1884static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section,
1885				  struct mtd_oob_region *oobregion)
1886{
1887	struct nand_chip *chip = mtd_to_nand(mtd);
1888	int off = BADBLOCK_MARKER_LENGTH;
1889
1890	if (section)
1891		return -ERANGE;
1892
1893	/*
1894	 * When SW correction is employed, one OMAP specific marker byte is
1895	 * reserved after each ECC step.
1896	 */
1897	off += ((chip->ecc.bytes + 1) * chip->ecc.steps);
1898	if (off >= mtd->oobsize)
1899		return -ERANGE;
1900
1901	oobregion->offset = off;
1902	oobregion->length = mtd->oobsize - off;
1903
1904	return 0;
1905}
1906
1907static const struct mtd_ooblayout_ops omap_sw_ooblayout_ops = {
1908	.ecc = omap_sw_ooblayout_ecc,
1909	.free = omap_sw_ooblayout_free,
1910};
1911
1912static int omap_nand_attach_chip(struct nand_chip *chip)
1913{
1914	struct mtd_info *mtd = nand_to_mtd(chip);
1915	struct omap_nand_info *info = mtd_to_omap(mtd);
1916	struct device *dev = &info->pdev->dev;
1917	int min_oobbytes = BADBLOCK_MARKER_LENGTH;
1918	int oobbytes_per_step;
1919	dma_cap_mask_t mask;
1920	int err;
1921
1922	if (chip->bbt_options & NAND_BBT_USE_FLASH)
1923		chip->bbt_options |= NAND_BBT_NO_OOB;
1924	else
1925		chip->options |= NAND_SKIP_BBTSCAN;
1926
1927	/* Re-populate low-level callbacks based on xfer modes */
1928	switch (info->xfer_type) {
1929	case NAND_OMAP_PREFETCH_POLLED:
1930		chip->legacy.read_buf = omap_read_buf_pref;
1931		chip->legacy.write_buf = omap_write_buf_pref;
1932		break;
1933
1934	case NAND_OMAP_POLLED:
1935		/* Use nand_base defaults for {read,write}_buf */
1936		break;
1937
1938	case NAND_OMAP_PREFETCH_DMA:
1939		dma_cap_zero(mask);
1940		dma_cap_set(DMA_SLAVE, mask);
1941		info->dma = dma_request_chan(dev->parent, "rxtx");
1942
1943		if (IS_ERR(info->dma)) {
1944			dev_err(dev, "DMA engine request failed\n");
1945			return PTR_ERR(info->dma);
1946		} else {
1947			struct dma_slave_config cfg;
1948
1949			memset(&cfg, 0, sizeof(cfg));
1950			cfg.src_addr = info->phys_base;
1951			cfg.dst_addr = info->phys_base;
1952			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1953			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1954			cfg.src_maxburst = 16;
1955			cfg.dst_maxburst = 16;
1956			err = dmaengine_slave_config(info->dma, &cfg);
1957			if (err) {
1958				dev_err(dev,
1959					"DMA engine slave config failed: %d\n",
1960					err);
1961				return err;
1962			}
1963			chip->legacy.read_buf = omap_read_buf_dma_pref;
1964			chip->legacy.write_buf = omap_write_buf_dma_pref;
1965		}
1966		break;
1967
1968	case NAND_OMAP_PREFETCH_IRQ:
1969		info->gpmc_irq_fifo = platform_get_irq(info->pdev, 0);
1970		if (info->gpmc_irq_fifo <= 0)
1971			return -ENODEV;
1972		err = devm_request_irq(dev, info->gpmc_irq_fifo,
1973				       omap_nand_irq, IRQF_SHARED,
1974				       "gpmc-nand-fifo", info);
1975		if (err) {
1976			dev_err(dev, "Requesting IRQ %d, error %d\n",
1977				info->gpmc_irq_fifo, err);
1978			info->gpmc_irq_fifo = 0;
1979			return err;
1980		}
1981
1982		info->gpmc_irq_count = platform_get_irq(info->pdev, 1);
1983		if (info->gpmc_irq_count <= 0)
1984			return -ENODEV;
1985		err = devm_request_irq(dev, info->gpmc_irq_count,
1986				       omap_nand_irq, IRQF_SHARED,
1987				       "gpmc-nand-count", info);
1988		if (err) {
1989			dev_err(dev, "Requesting IRQ %d, error %d\n",
1990				info->gpmc_irq_count, err);
1991			info->gpmc_irq_count = 0;
1992			return err;
1993		}
1994
1995		chip->legacy.read_buf = omap_read_buf_irq_pref;
1996		chip->legacy.write_buf = omap_write_buf_irq_pref;
1997
1998		break;
1999
2000	default:
2001		dev_err(dev, "xfer_type %d not supported!\n", info->xfer_type);
2002		return -EINVAL;
2003	}
2004
2005	if (!omap2_nand_ecc_check(info))
2006		return -EINVAL;
2007
2008	/*
2009	 * Bail out earlier to let NAND_ECC_ENGINE_TYPE_SOFT code create its own
2010	 * ooblayout instead of using ours.
2011	 */
2012	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW) {
2013		chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
2014		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
2015		return 0;
2016	}
2017
2018	/* Populate MTD interface based on ECC scheme */
2019	switch (info->ecc_opt) {
2020	case OMAP_ECC_HAM1_CODE_HW:
2021		dev_info(dev, "nand: using OMAP_ECC_HAM1_CODE_HW\n");
2022		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2023		chip->ecc.bytes		= 3;
2024		chip->ecc.size		= 512;
2025		chip->ecc.strength	= 1;
2026		chip->ecc.calculate	= omap_calculate_ecc;
2027		chip->ecc.hwctl		= omap_enable_hwecc;
2028		chip->ecc.correct	= omap_correct_data;
2029		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2030		oobbytes_per_step	= chip->ecc.bytes;
2031
2032		if (!(chip->options & NAND_BUSWIDTH_16))
2033			min_oobbytes	= 1;
2034
2035		break;
2036
2037	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
2038		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW\n");
2039		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2040		chip->ecc.size		= 512;
2041		chip->ecc.bytes		= 7;
2042		chip->ecc.strength	= 4;
2043		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2044		chip->ecc.correct	= nand_bch_correct_data;
2045		chip->ecc.calculate	= omap_calculate_ecc_bch_sw;
2046		mtd_set_ooblayout(mtd, &omap_sw_ooblayout_ops);
2047		/* Reserve one byte for the OMAP marker */
2048		oobbytes_per_step	= chip->ecc.bytes + 1;
2049		/* Software BCH library is used for locating errors */
2050		chip->ecc.priv		= nand_bch_init(mtd);
2051		if (!chip->ecc.priv) {
2052			dev_err(dev, "Unable to use BCH library\n");
2053			return -EINVAL;
2054		}
2055		break;
2056
2057	case OMAP_ECC_BCH4_CODE_HW:
2058		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW ECC scheme\n");
2059		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2060		chip->ecc.size		= 512;
2061		/* 14th bit is kept reserved for ROM-code compatibility */
2062		chip->ecc.bytes		= 7 + 1;
2063		chip->ecc.strength	= 4;
2064		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2065		chip->ecc.correct	= omap_elm_correct_data;
2066		chip->ecc.read_page	= omap_read_page_bch;
2067		chip->ecc.write_page	= omap_write_page_bch;
2068		chip->ecc.write_subpage	= omap_write_subpage_bch;
2069		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2070		oobbytes_per_step	= chip->ecc.bytes;
2071
2072		err = elm_config(info->elm_dev, BCH4_ECC,
2073				 mtd->writesize / chip->ecc.size,
2074				 chip->ecc.size, chip->ecc.bytes);
2075		if (err < 0)
2076			return err;
2077		break;
2078
2079	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
2080		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
2081		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2082		chip->ecc.size		= 512;
2083		chip->ecc.bytes		= 13;
2084		chip->ecc.strength	= 8;
2085		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2086		chip->ecc.correct	= nand_bch_correct_data;
2087		chip->ecc.calculate	= omap_calculate_ecc_bch_sw;
2088		mtd_set_ooblayout(mtd, &omap_sw_ooblayout_ops);
2089		/* Reserve one byte for the OMAP marker */
2090		oobbytes_per_step	= chip->ecc.bytes + 1;
2091		/* Software BCH library is used for locating errors */
2092		chip->ecc.priv		= nand_bch_init(mtd);
2093		if (!chip->ecc.priv) {
2094			dev_err(dev, "unable to use BCH library\n");
2095			return -EINVAL;
2096		}
2097		break;
2098
2099	case OMAP_ECC_BCH8_CODE_HW:
2100		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme\n");
2101		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2102		chip->ecc.size		= 512;
2103		/* 14th bit is kept reserved for ROM-code compatibility */
2104		chip->ecc.bytes		= 13 + 1;
2105		chip->ecc.strength	= 8;
2106		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2107		chip->ecc.correct	= omap_elm_correct_data;
2108		chip->ecc.read_page	= omap_read_page_bch;
2109		chip->ecc.write_page	= omap_write_page_bch;
2110		chip->ecc.write_subpage	= omap_write_subpage_bch;
2111		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2112		oobbytes_per_step	= chip->ecc.bytes;
2113
2114		err = elm_config(info->elm_dev, BCH8_ECC,
2115				 mtd->writesize / chip->ecc.size,
2116				 chip->ecc.size, chip->ecc.bytes);
2117		if (err < 0)
2118			return err;
2119
2120		break;
2121
2122	case OMAP_ECC_BCH16_CODE_HW:
2123		pr_info("Using OMAP_ECC_BCH16_CODE_HW ECC scheme\n");
2124		chip->ecc.engine_type	= NAND_ECC_ENGINE_TYPE_ON_HOST;
2125		chip->ecc.size		= 512;
2126		chip->ecc.bytes		= 26;
2127		chip->ecc.strength	= 16;
2128		chip->ecc.hwctl		= omap_enable_hwecc_bch;
2129		chip->ecc.correct	= omap_elm_correct_data;
2130		chip->ecc.read_page	= omap_read_page_bch;
2131		chip->ecc.write_page	= omap_write_page_bch;
2132		chip->ecc.write_subpage	= omap_write_subpage_bch;
2133		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
2134		oobbytes_per_step	= chip->ecc.bytes;
2135
2136		err = elm_config(info->elm_dev, BCH16_ECC,
2137				 mtd->writesize / chip->ecc.size,
2138				 chip->ecc.size, chip->ecc.bytes);
2139		if (err < 0)
2140			return err;
2141
2142		break;
2143	default:
2144		dev_err(dev, "Invalid or unsupported ECC scheme\n");
2145		return -EINVAL;
2146	}
2147
2148	/* Check if NAND device's OOB is enough to store ECC signatures */
2149	min_oobbytes += (oobbytes_per_step *
2150			 (mtd->writesize / chip->ecc.size));
2151	if (mtd->oobsize < min_oobbytes) {
2152		dev_err(dev,
2153			"Not enough OOB bytes: required = %d, available=%d\n",
2154			min_oobbytes, mtd->oobsize);
2155		return -EINVAL;
2156	}
2157
2158	return 0;
2159}
2160
2161static const struct nand_controller_ops omap_nand_controller_ops = {
2162	.attach_chip = omap_nand_attach_chip,
2163};
2164
2165/* Shared among all NAND instances to synchronize access to the ECC Engine */
2166static struct nand_controller omap_gpmc_controller;
2167static bool omap_gpmc_controller_initialized;
2168
2169static int omap_nand_probe(struct platform_device *pdev)
2170{
2171	struct omap_nand_info		*info;
2172	struct mtd_info			*mtd;
2173	struct nand_chip		*nand_chip;
2174	int				err;
2175	struct resource			*res;
2176	struct device			*dev = &pdev->dev;
2177
2178	info = devm_kzalloc(&pdev->dev, sizeof(struct omap_nand_info),
2179				GFP_KERNEL);
2180	if (!info)
2181		return -ENOMEM;
2182
2183	info->pdev = pdev;
2184
2185	err = omap_get_dt_info(dev, info);
2186	if (err)
2187		return err;
2188
2189	info->ops = gpmc_omap_get_nand_ops(&info->reg, info->gpmc_cs);
2190	if (!info->ops) {
2191		dev_err(&pdev->dev, "Failed to get GPMC->NAND interface\n");
2192		return -ENODEV;
2193	}
2194
2195	nand_chip		= &info->nand;
2196	mtd			= nand_to_mtd(nand_chip);
2197	mtd->dev.parent		= &pdev->dev;
2198	nand_chip->ecc.priv	= NULL;
2199	nand_set_flash_node(nand_chip, dev->of_node);
2200
2201	if (!mtd->name) {
2202		mtd->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
2203					   "omap2-nand.%d", info->gpmc_cs);
2204		if (!mtd->name) {
2205			dev_err(&pdev->dev, "Failed to set MTD name\n");
2206			return -ENOMEM;
2207		}
2208	}
2209
2210	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2211	nand_chip->legacy.IO_ADDR_R = devm_ioremap_resource(&pdev->dev, res);
2212	if (IS_ERR(nand_chip->legacy.IO_ADDR_R))
2213		return PTR_ERR(nand_chip->legacy.IO_ADDR_R);
2214
2215	info->phys_base = res->start;
2216
2217	if (!omap_gpmc_controller_initialized) {
2218		omap_gpmc_controller.ops = &omap_nand_controller_ops;
2219		nand_controller_init(&omap_gpmc_controller);
2220		omap_gpmc_controller_initialized = true;
2221	}
2222
2223	nand_chip->controller = &omap_gpmc_controller;
2224
2225	nand_chip->legacy.IO_ADDR_W = nand_chip->legacy.IO_ADDR_R;
2226	nand_chip->legacy.cmd_ctrl  = omap_hwcontrol;
2227
2228	info->ready_gpiod = devm_gpiod_get_optional(&pdev->dev, "rb",
2229						    GPIOD_IN);
2230	if (IS_ERR(info->ready_gpiod)) {
2231		dev_err(dev, "failed to get ready gpio\n");
2232		return PTR_ERR(info->ready_gpiod);
2233	}
2234
2235	/*
2236	 * If RDY/BSY line is connected to OMAP then use the omap ready
2237	 * function and the generic nand_wait function which reads the status
2238	 * register after monitoring the RDY/BSY line. Otherwise use a standard
2239	 * chip delay which is slightly more than tR (AC Timing) of the NAND
2240	 * device and read status register until you get a failure or success
2241	 */
2242	if (info->ready_gpiod) {
2243		nand_chip->legacy.dev_ready = omap_dev_ready;
2244		nand_chip->legacy.chip_delay = 0;
2245	} else {
2246		nand_chip->legacy.waitfunc = omap_wait;
2247		nand_chip->legacy.chip_delay = 50;
2248	}
2249
2250	if (info->flash_bbt)
2251		nand_chip->bbt_options |= NAND_BBT_USE_FLASH;
2252
2253	/* scan NAND device connected to chip controller */
2254	nand_chip->options |= info->devsize & NAND_BUSWIDTH_16;
2255
2256	err = nand_scan(nand_chip, 1);
2257	if (err)
2258		goto return_error;
2259
2260	err = mtd_device_register(mtd, NULL, 0);
2261	if (err)
2262		goto cleanup_nand;
2263
2264	platform_set_drvdata(pdev, mtd);
2265
2266	return 0;
2267
2268cleanup_nand:
2269	nand_cleanup(nand_chip);
2270
2271return_error:
2272	if (!IS_ERR_OR_NULL(info->dma))
2273		dma_release_channel(info->dma);
2274	if (nand_chip->ecc.priv) {
2275		nand_bch_free(nand_chip->ecc.priv);
2276		nand_chip->ecc.priv = NULL;
2277	}
2278	return err;
2279}
2280
2281static int omap_nand_remove(struct platform_device *pdev)
2282{
2283	struct mtd_info *mtd = platform_get_drvdata(pdev);
2284	struct nand_chip *nand_chip = mtd_to_nand(mtd);
2285	struct omap_nand_info *info = mtd_to_omap(mtd);
2286	int ret;
2287
2288	if (nand_chip->ecc.priv) {
2289		nand_bch_free(nand_chip->ecc.priv);
2290		nand_chip->ecc.priv = NULL;
2291	}
2292	if (info->dma)
2293		dma_release_channel(info->dma);
2294	ret = mtd_device_unregister(mtd);
2295	WARN_ON(ret);
2296	nand_cleanup(nand_chip);
2297	return ret;
2298}
2299
2300static const struct of_device_id omap_nand_ids[] = {
2301	{ .compatible = "ti,omap2-nand", },
2302	{},
2303};
2304MODULE_DEVICE_TABLE(of, omap_nand_ids);
2305
2306static struct platform_driver omap_nand_driver = {
2307	.probe		= omap_nand_probe,
2308	.remove		= omap_nand_remove,
2309	.driver		= {
2310		.name	= DRIVER_NAME,
2311		.of_match_table = of_match_ptr(omap_nand_ids),
2312	},
2313};
2314
2315module_platform_driver(omap_nand_driver);
2316
2317MODULE_ALIAS("platform:" DRIVER_NAME);
2318MODULE_LICENSE("GPL");
2319MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");
2320