1/*
2 * Copyright © 2004 Texas Instruments, Jian Zhang <jzhang@ti.com>
3 * Copyright © 2004 Micron Technology Inc.
4 * Copyright © 2004 David Brownell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/platform_device.h>
12#include <linux/dmaengine.h>
13#include <linux/dma-mapping.h>
14#include <linux/delay.h>
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/jiffies.h>
18#include <linux/sched.h>
19#include <linux/mtd/mtd.h>
20#include <linux/mtd/nand.h>
21#include <linux/mtd/partitions.h>
22#include <linux/omap-dma.h>
23#include <linux/io.h>
24#include <linux/slab.h>
25#include <linux/of.h>
26#include <linux/of_device.h>
27
28#include <linux/mtd/nand_bch.h>
29#include <linux/platform_data/elm.h>
30
31#include <linux/platform_data/mtd-nand-omap2.h>
32
33#define	DRIVER_NAME	"omap2-nand"
34#define	OMAP_NAND_TIMEOUT_MS	5000
35
36#define NAND_Ecc_P1e		(1 << 0)
37#define NAND_Ecc_P2e		(1 << 1)
38#define NAND_Ecc_P4e		(1 << 2)
39#define NAND_Ecc_P8e		(1 << 3)
40#define NAND_Ecc_P16e		(1 << 4)
41#define NAND_Ecc_P32e		(1 << 5)
42#define NAND_Ecc_P64e		(1 << 6)
43#define NAND_Ecc_P128e		(1 << 7)
44#define NAND_Ecc_P256e		(1 << 8)
45#define NAND_Ecc_P512e		(1 << 9)
46#define NAND_Ecc_P1024e		(1 << 10)
47#define NAND_Ecc_P2048e		(1 << 11)
48
49#define NAND_Ecc_P1o		(1 << 16)
50#define NAND_Ecc_P2o		(1 << 17)
51#define NAND_Ecc_P4o		(1 << 18)
52#define NAND_Ecc_P8o		(1 << 19)
53#define NAND_Ecc_P16o		(1 << 20)
54#define NAND_Ecc_P32o		(1 << 21)
55#define NAND_Ecc_P64o		(1 << 22)
56#define NAND_Ecc_P128o		(1 << 23)
57#define NAND_Ecc_P256o		(1 << 24)
58#define NAND_Ecc_P512o		(1 << 25)
59#define NAND_Ecc_P1024o		(1 << 26)
60#define NAND_Ecc_P2048o		(1 << 27)
61
62#define TF(value)	(value ? 1 : 0)
63
64#define P2048e(a)	(TF(a & NAND_Ecc_P2048e)	<< 0)
65#define P2048o(a)	(TF(a & NAND_Ecc_P2048o)	<< 1)
66#define P1e(a)		(TF(a & NAND_Ecc_P1e)		<< 2)
67#define P1o(a)		(TF(a & NAND_Ecc_P1o)		<< 3)
68#define P2e(a)		(TF(a & NAND_Ecc_P2e)		<< 4)
69#define P2o(a)		(TF(a & NAND_Ecc_P2o)		<< 5)
70#define P4e(a)		(TF(a & NAND_Ecc_P4e)		<< 6)
71#define P4o(a)		(TF(a & NAND_Ecc_P4o)		<< 7)
72
73#define P8e(a)		(TF(a & NAND_Ecc_P8e)		<< 0)
74#define P8o(a)		(TF(a & NAND_Ecc_P8o)		<< 1)
75#define P16e(a)		(TF(a & NAND_Ecc_P16e)		<< 2)
76#define P16o(a)		(TF(a & NAND_Ecc_P16o)		<< 3)
77#define P32e(a)		(TF(a & NAND_Ecc_P32e)		<< 4)
78#define P32o(a)		(TF(a & NAND_Ecc_P32o)		<< 5)
79#define P64e(a)		(TF(a & NAND_Ecc_P64e)		<< 6)
80#define P64o(a)		(TF(a & NAND_Ecc_P64o)		<< 7)
81
82#define P128e(a)	(TF(a & NAND_Ecc_P128e)		<< 0)
83#define P128o(a)	(TF(a & NAND_Ecc_P128o)		<< 1)
84#define P256e(a)	(TF(a & NAND_Ecc_P256e)		<< 2)
85#define P256o(a)	(TF(a & NAND_Ecc_P256o)		<< 3)
86#define P512e(a)	(TF(a & NAND_Ecc_P512e)		<< 4)
87#define P512o(a)	(TF(a & NAND_Ecc_P512o)		<< 5)
88#define P1024e(a)	(TF(a & NAND_Ecc_P1024e)	<< 6)
89#define P1024o(a)	(TF(a & NAND_Ecc_P1024o)	<< 7)
90
91#define P8e_s(a)	(TF(a & NAND_Ecc_P8e)		<< 0)
92#define P8o_s(a)	(TF(a & NAND_Ecc_P8o)		<< 1)
93#define P16e_s(a)	(TF(a & NAND_Ecc_P16e)		<< 2)
94#define P16o_s(a)	(TF(a & NAND_Ecc_P16o)		<< 3)
95#define P1e_s(a)	(TF(a & NAND_Ecc_P1e)		<< 4)
96#define P1o_s(a)	(TF(a & NAND_Ecc_P1o)		<< 5)
97#define P2e_s(a)	(TF(a & NAND_Ecc_P2e)		<< 6)
98#define P2o_s(a)	(TF(a & NAND_Ecc_P2o)		<< 7)
99
100#define P4e_s(a)	(TF(a & NAND_Ecc_P4e)		<< 0)
101#define P4o_s(a)	(TF(a & NAND_Ecc_P4o)		<< 1)
102
103#define	PREFETCH_CONFIG1_CS_SHIFT	24
104#define	ECC_CONFIG_CS_SHIFT		1
105#define	CS_MASK				0x7
106#define	ENABLE_PREFETCH			(0x1 << 7)
107#define	DMA_MPU_MODE_SHIFT		2
108#define	ECCSIZE0_SHIFT			12
109#define	ECCSIZE1_SHIFT			22
110#define	ECC1RESULTSIZE			0x1
111#define	ECCCLEAR			0x100
112#define	ECC1				0x1
113#define	PREFETCH_FIFOTHRESHOLD_MAX	0x40
114#define	PREFETCH_FIFOTHRESHOLD(val)	((val) << 8)
115#define	PREFETCH_STATUS_COUNT(val)	(val & 0x00003fff)
116#define	PREFETCH_STATUS_FIFO_CNT(val)	((val >> 24) & 0x7F)
117#define	STATUS_BUFF_EMPTY		0x00000001
118
119#define OMAP24XX_DMA_GPMC		4
120
121#define SECTOR_BYTES		512
122/* 4 bit padding to make byte aligned, 56 = 52 + 4 */
123#define BCH4_BIT_PAD		4
124
125/* GPMC ecc engine settings for read */
126#define BCH_WRAPMODE_1		1	/* BCH wrap mode 1 */
127#define BCH8R_ECC_SIZE0		0x1a	/* ecc_size0 = 26 */
128#define BCH8R_ECC_SIZE1		0x2	/* ecc_size1 = 2 */
129#define BCH4R_ECC_SIZE0		0xd	/* ecc_size0 = 13 */
130#define BCH4R_ECC_SIZE1		0x3	/* ecc_size1 = 3 */
131
132/* GPMC ecc engine settings for write */
133#define BCH_WRAPMODE_6		6	/* BCH wrap mode 6 */
134#define BCH_ECC_SIZE0		0x0	/* ecc_size0 = 0, no oob protection */
135#define BCH_ECC_SIZE1		0x20	/* ecc_size1 = 32 */
136
137#define BADBLOCK_MARKER_LENGTH		2
138
139static u_char bch16_vector[] = {0xf5, 0x24, 0x1c, 0xd0, 0x61, 0xb3, 0xf1, 0x55,
140				0x2e, 0x2c, 0x86, 0xa3, 0xed, 0x36, 0x1b, 0x78,
141				0x48, 0x76, 0xa9, 0x3b, 0x97, 0xd1, 0x7a, 0x93,
142				0x07, 0x0e};
143static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
144	0xac, 0x6b, 0xff, 0x99, 0x7b};
145static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
146
147/* Shared among all NAND instances to synchronize access to the ECC Engine */
148static struct nand_hw_control omap_gpmc_controller = {
149	.lock = __SPIN_LOCK_UNLOCKED(omap_gpmc_controller.lock),
150	.wq = __WAIT_QUEUE_HEAD_INITIALIZER(omap_gpmc_controller.wq),
151};
152
153struct omap_nand_info {
154	struct omap_nand_platform_data	*pdata;
155	struct mtd_info			mtd;
156	struct nand_chip		nand;
157	struct platform_device		*pdev;
158
159	int				gpmc_cs;
160	unsigned long			phys_base;
161	enum omap_ecc			ecc_opt;
162	struct completion		comp;
163	struct dma_chan			*dma;
164	int				gpmc_irq_fifo;
165	int				gpmc_irq_count;
166	enum {
167		OMAP_NAND_IO_READ = 0,	/* read */
168		OMAP_NAND_IO_WRITE,	/* write */
169	} iomode;
170	u_char				*buf;
171	int					buf_len;
172	struct gpmc_nand_regs		reg;
173	/* generated at runtime depending on ECC algorithm and layout selected */
174	struct nand_ecclayout		oobinfo;
175	/* fields specific for BCHx_HW ECC scheme */
176	struct device			*elm_dev;
177	struct device_node		*of_node;
178};
179
180/**
181 * omap_prefetch_enable - configures and starts prefetch transfer
182 * @cs: cs (chip select) number
183 * @fifo_th: fifo threshold to be used for read/ write
184 * @dma_mode: dma mode enable (1) or disable (0)
185 * @u32_count: number of bytes to be transferred
186 * @is_write: prefetch read(0) or write post(1) mode
187 */
188static int omap_prefetch_enable(int cs, int fifo_th, int dma_mode,
189	unsigned int u32_count, int is_write, struct omap_nand_info *info)
190{
191	u32 val;
192
193	if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX)
194		return -1;
195
196	if (readl(info->reg.gpmc_prefetch_control))
197		return -EBUSY;
198
199	/* Set the amount of bytes to be prefetched */
200	writel(u32_count, info->reg.gpmc_prefetch_config2);
201
202	/* Set dma/mpu mode, the prefetch read / post write and
203	 * enable the engine. Set which cs is has requested for.
204	 */
205	val = ((cs << PREFETCH_CONFIG1_CS_SHIFT) |
206		PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH |
207		(dma_mode << DMA_MPU_MODE_SHIFT) | (0x1 & is_write));
208	writel(val, info->reg.gpmc_prefetch_config1);
209
210	/*  Start the prefetch engine */
211	writel(0x1, info->reg.gpmc_prefetch_control);
212
213	return 0;
214}
215
216/**
217 * omap_prefetch_reset - disables and stops the prefetch engine
218 */
219static int omap_prefetch_reset(int cs, struct omap_nand_info *info)
220{
221	u32 config1;
222
223	/* check if the same module/cs is trying to reset */
224	config1 = readl(info->reg.gpmc_prefetch_config1);
225	if (((config1 >> PREFETCH_CONFIG1_CS_SHIFT) & CS_MASK) != cs)
226		return -EINVAL;
227
228	/* Stop the PFPW engine */
229	writel(0x0, info->reg.gpmc_prefetch_control);
230
231	/* Reset/disable the PFPW engine */
232	writel(0x0, info->reg.gpmc_prefetch_config1);
233
234	return 0;
235}
236
237/**
238 * omap_hwcontrol - hardware specific access to control-lines
239 * @mtd: MTD device structure
240 * @cmd: command to device
241 * @ctrl:
242 * NAND_NCE: bit 0 -> don't care
243 * NAND_CLE: bit 1 -> Command Latch
244 * NAND_ALE: bit 2 -> Address Latch
245 *
246 * NOTE: boards may use different bits for these!!
247 */
248static void omap_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
249{
250	struct omap_nand_info *info = container_of(mtd,
251					struct omap_nand_info, mtd);
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->priv;
274
275	ioread8_rep(nand->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 = container_of(mtd,
287						struct omap_nand_info, mtd);
288	u_char *p = (u_char *)buf;
289	u32	status = 0;
290
291	while (len--) {
292		iowrite8(*p++, info->nand.IO_ADDR_W);
293		/* wait until buffer is available for write */
294		do {
295			status = readl(info->reg.gpmc_status) &
296					STATUS_BUFF_EMPTY;
297		} while (!status);
298	}
299}
300
301/**
302 * omap_read_buf16 - read data from NAND controller into buffer
303 * @mtd: MTD device structure
304 * @buf: buffer to store date
305 * @len: number of bytes to read
306 */
307static void omap_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
308{
309	struct nand_chip *nand = mtd->priv;
310
311	ioread16_rep(nand->IO_ADDR_R, buf, len / 2);
312}
313
314/**
315 * omap_write_buf16 - write buffer to NAND controller
316 * @mtd: MTD device structure
317 * @buf: data buffer
318 * @len: number of bytes to write
319 */
320static void omap_write_buf16(struct mtd_info *mtd, const u_char * buf, int len)
321{
322	struct omap_nand_info *info = container_of(mtd,
323						struct omap_nand_info, mtd);
324	u16 *p = (u16 *) buf;
325	u32	status = 0;
326	/* FIXME try bursts of writesw() or DMA ... */
327	len >>= 1;
328
329	while (len--) {
330		iowrite16(*p++, info->nand.IO_ADDR_W);
331		/* wait until buffer is available for write */
332		do {
333			status = readl(info->reg.gpmc_status) &
334					STATUS_BUFF_EMPTY;
335		} while (!status);
336	}
337}
338
339/**
340 * omap_read_buf_pref - read data from NAND controller into buffer
341 * @mtd: MTD device structure
342 * @buf: buffer to store date
343 * @len: number of bytes to read
344 */
345static void omap_read_buf_pref(struct mtd_info *mtd, u_char *buf, int len)
346{
347	struct omap_nand_info *info = container_of(mtd,
348						struct omap_nand_info, mtd);
349	uint32_t r_count = 0;
350	int ret = 0;
351	u32 *p = (u32 *)buf;
352
353	/* take care of subpage reads */
354	if (len % 4) {
355		if (info->nand.options & NAND_BUSWIDTH_16)
356			omap_read_buf16(mtd, buf, len % 4);
357		else
358			omap_read_buf8(mtd, buf, len % 4);
359		p = (u32 *) (buf + len % 4);
360		len -= len % 4;
361	}
362
363	/* configure and start prefetch transfer */
364	ret = omap_prefetch_enable(info->gpmc_cs,
365			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x0, info);
366	if (ret) {
367		/* PFPW engine is busy, use cpu copy method */
368		if (info->nand.options & NAND_BUSWIDTH_16)
369			omap_read_buf16(mtd, (u_char *)p, len);
370		else
371			omap_read_buf8(mtd, (u_char *)p, len);
372	} else {
373		do {
374			r_count = readl(info->reg.gpmc_prefetch_status);
375			r_count = PREFETCH_STATUS_FIFO_CNT(r_count);
376			r_count = r_count >> 2;
377			ioread32_rep(info->nand.IO_ADDR_R, p, r_count);
378			p += r_count;
379			len -= r_count << 2;
380		} while (len);
381		/* disable and stop the PFPW engine */
382		omap_prefetch_reset(info->gpmc_cs, info);
383	}
384}
385
386/**
387 * omap_write_buf_pref - write buffer to NAND controller
388 * @mtd: MTD device structure
389 * @buf: data buffer
390 * @len: number of bytes to write
391 */
392static void omap_write_buf_pref(struct mtd_info *mtd,
393					const u_char *buf, int len)
394{
395	struct omap_nand_info *info = container_of(mtd,
396						struct omap_nand_info, mtd);
397	uint32_t w_count = 0;
398	int i = 0, ret = 0;
399	u16 *p = (u16 *)buf;
400	unsigned long tim, limit;
401	u32 val;
402
403	/* take care of subpage writes */
404	if (len % 2 != 0) {
405		writeb(*buf, info->nand.IO_ADDR_W);
406		p = (u16 *)(buf + 1);
407		len--;
408	}
409
410	/*  configure and start prefetch transfer */
411	ret = omap_prefetch_enable(info->gpmc_cs,
412			PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x1, info);
413	if (ret) {
414		/* PFPW engine is busy, use cpu copy method */
415		if (info->nand.options & NAND_BUSWIDTH_16)
416			omap_write_buf16(mtd, (u_char *)p, len);
417		else
418			omap_write_buf8(mtd, (u_char *)p, len);
419	} else {
420		while (len) {
421			w_count = readl(info->reg.gpmc_prefetch_status);
422			w_count = PREFETCH_STATUS_FIFO_CNT(w_count);
423			w_count = w_count >> 1;
424			for (i = 0; (i < w_count) && len; i++, len -= 2)
425				iowrite16(*p++, info->nand.IO_ADDR_W);
426		}
427		/* wait for data to flushed-out before reset the prefetch */
428		tim = 0;
429		limit = (loops_per_jiffy *
430					msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
431		do {
432			cpu_relax();
433			val = readl(info->reg.gpmc_prefetch_status);
434			val = PREFETCH_STATUS_COUNT(val);
435		} while (val && (tim++ < limit));
436
437		/* disable and stop the PFPW engine */
438		omap_prefetch_reset(info->gpmc_cs, info);
439	}
440}
441
442/*
443 * omap_nand_dma_callback: callback on the completion of dma transfer
444 * @data: pointer to completion data structure
445 */
446static void omap_nand_dma_callback(void *data)
447{
448	complete((struct completion *) data);
449}
450
451/*
452 * omap_nand_dma_transfer: configure and start dma transfer
453 * @mtd: MTD device structure
454 * @addr: virtual address in RAM of source/destination
455 * @len: number of data bytes to be transferred
456 * @is_write: flag for read/write operation
457 */
458static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
459					unsigned int len, int is_write)
460{
461	struct omap_nand_info *info = container_of(mtd,
462					struct omap_nand_info, mtd);
463	struct dma_async_tx_descriptor *tx;
464	enum dma_data_direction dir = is_write ? DMA_TO_DEVICE :
465							DMA_FROM_DEVICE;
466	struct scatterlist sg;
467	unsigned long tim, limit;
468	unsigned n;
469	int ret;
470	u32 val;
471
472	if (addr >= high_memory) {
473		struct page *p1;
474
475		if (((size_t)addr & PAGE_MASK) !=
476			((size_t)(addr + len - 1) & PAGE_MASK))
477			goto out_copy;
478		p1 = vmalloc_to_page(addr);
479		if (!p1)
480			goto out_copy;
481		addr = page_address(p1) + ((size_t)addr & ~PAGE_MASK);
482	}
483
484	sg_init_one(&sg, addr, len);
485	n = dma_map_sg(info->dma->device->dev, &sg, 1, dir);
486	if (n == 0) {
487		dev_err(&info->pdev->dev,
488			"Couldn't DMA map a %d byte buffer\n", len);
489		goto out_copy;
490	}
491
492	tx = dmaengine_prep_slave_sg(info->dma, &sg, n,
493		is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
494		DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
495	if (!tx)
496		goto out_copy_unmap;
497
498	tx->callback = omap_nand_dma_callback;
499	tx->callback_param = &info->comp;
500	dmaengine_submit(tx);
501
502	/*  configure and start prefetch transfer */
503	ret = omap_prefetch_enable(info->gpmc_cs,
504		PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write, info);
505	if (ret)
506		/* PFPW engine is busy, use cpu copy method */
507		goto out_copy_unmap;
508
509	init_completion(&info->comp);
510	dma_async_issue_pending(info->dma);
511
512	/* setup and start DMA using dma_addr */
513	wait_for_completion(&info->comp);
514	tim = 0;
515	limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
516
517	do {
518		cpu_relax();
519		val = readl(info->reg.gpmc_prefetch_status);
520		val = PREFETCH_STATUS_COUNT(val);
521	} while (val && (tim++ < limit));
522
523	/* disable and stop the PFPW engine */
524	omap_prefetch_reset(info->gpmc_cs, info);
525
526	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
527	return 0;
528
529out_copy_unmap:
530	dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
531out_copy:
532	if (info->nand.options & NAND_BUSWIDTH_16)
533		is_write == 0 ? omap_read_buf16(mtd, (u_char *) addr, len)
534			: omap_write_buf16(mtd, (u_char *) addr, len);
535	else
536		is_write == 0 ? omap_read_buf8(mtd, (u_char *) addr, len)
537			: omap_write_buf8(mtd, (u_char *) addr, len);
538	return 0;
539}
540
541/**
542 * omap_read_buf_dma_pref - read data from NAND controller into buffer
543 * @mtd: MTD device structure
544 * @buf: buffer to store date
545 * @len: number of bytes to read
546 */
547static void omap_read_buf_dma_pref(struct mtd_info *mtd, u_char *buf, int len)
548{
549	if (len <= mtd->oobsize)
550		omap_read_buf_pref(mtd, buf, len);
551	else
552		/* start transfer in DMA mode */
553		omap_nand_dma_transfer(mtd, buf, len, 0x0);
554}
555
556/**
557 * omap_write_buf_dma_pref - write buffer to NAND controller
558 * @mtd: MTD device structure
559 * @buf: data buffer
560 * @len: number of bytes to write
561 */
562static void omap_write_buf_dma_pref(struct mtd_info *mtd,
563					const u_char *buf, int len)
564{
565	if (len <= mtd->oobsize)
566		omap_write_buf_pref(mtd, buf, len);
567	else
568		/* start transfer in DMA mode */
569		omap_nand_dma_transfer(mtd, (u_char *) buf, len, 0x1);
570}
571
572/*
573 * omap_nand_irq - GPMC irq handler
574 * @this_irq: gpmc irq number
575 * @dev: omap_nand_info structure pointer is passed here
576 */
577static irqreturn_t omap_nand_irq(int this_irq, void *dev)
578{
579	struct omap_nand_info *info = (struct omap_nand_info *) dev;
580	u32 bytes;
581
582	bytes = readl(info->reg.gpmc_prefetch_status);
583	bytes = PREFETCH_STATUS_FIFO_CNT(bytes);
584	bytes = bytes  & 0xFFFC; /* io in multiple of 4 bytes */
585	if (info->iomode == OMAP_NAND_IO_WRITE) { /* checks for write io */
586		if (this_irq == info->gpmc_irq_count)
587			goto done;
588
589		if (info->buf_len && (info->buf_len < bytes))
590			bytes = info->buf_len;
591		else if (!info->buf_len)
592			bytes = 0;
593		iowrite32_rep(info->nand.IO_ADDR_W,
594						(u32 *)info->buf, bytes >> 2);
595		info->buf = info->buf + bytes;
596		info->buf_len -= bytes;
597
598	} else {
599		ioread32_rep(info->nand.IO_ADDR_R,
600						(u32 *)info->buf, bytes >> 2);
601		info->buf = info->buf + bytes;
602
603		if (this_irq == info->gpmc_irq_count)
604			goto done;
605	}
606
607	return IRQ_HANDLED;
608
609done:
610	complete(&info->comp);
611
612	disable_irq_nosync(info->gpmc_irq_fifo);
613	disable_irq_nosync(info->gpmc_irq_count);
614
615	return IRQ_HANDLED;
616}
617
618/*
619 * omap_read_buf_irq_pref - read data from NAND controller into buffer
620 * @mtd: MTD device structure
621 * @buf: buffer to store date
622 * @len: number of bytes to read
623 */
624static void omap_read_buf_irq_pref(struct mtd_info *mtd, u_char *buf, int len)
625{
626	struct omap_nand_info *info = container_of(mtd,
627						struct omap_nand_info, mtd);
628	int ret = 0;
629
630	if (len <= mtd->oobsize) {
631		omap_read_buf_pref(mtd, buf, len);
632		return;
633	}
634
635	info->iomode = OMAP_NAND_IO_READ;
636	info->buf = buf;
637	init_completion(&info->comp);
638
639	/*  configure and start prefetch transfer */
640	ret = omap_prefetch_enable(info->gpmc_cs,
641			PREFETCH_FIFOTHRESHOLD_MAX/2, 0x0, len, 0x0, info);
642	if (ret)
643		/* PFPW engine is busy, use cpu copy method */
644		goto out_copy;
645
646	info->buf_len = len;
647
648	enable_irq(info->gpmc_irq_count);
649	enable_irq(info->gpmc_irq_fifo);
650
651	/* waiting for read to complete */
652	wait_for_completion(&info->comp);
653
654	/* disable and stop the PFPW engine */
655	omap_prefetch_reset(info->gpmc_cs, info);
656	return;
657
658out_copy:
659	if (info->nand.options & NAND_BUSWIDTH_16)
660		omap_read_buf16(mtd, buf, len);
661	else
662		omap_read_buf8(mtd, buf, len);
663}
664
665/*
666 * omap_write_buf_irq_pref - write buffer to NAND controller
667 * @mtd: MTD device structure
668 * @buf: data buffer
669 * @len: number of bytes to write
670 */
671static void omap_write_buf_irq_pref(struct mtd_info *mtd,
672					const u_char *buf, int len)
673{
674	struct omap_nand_info *info = container_of(mtd,
675						struct omap_nand_info, mtd);
676	int ret = 0;
677	unsigned long tim, limit;
678	u32 val;
679
680	if (len <= mtd->oobsize) {
681		omap_write_buf_pref(mtd, buf, len);
682		return;
683	}
684
685	info->iomode = OMAP_NAND_IO_WRITE;
686	info->buf = (u_char *) buf;
687	init_completion(&info->comp);
688
689	/* configure and start prefetch transfer : size=24 */
690	ret = omap_prefetch_enable(info->gpmc_cs,
691		(PREFETCH_FIFOTHRESHOLD_MAX * 3) / 8, 0x0, len, 0x1, info);
692	if (ret)
693		/* PFPW engine is busy, use cpu copy method */
694		goto out_copy;
695
696	info->buf_len = len;
697
698	enable_irq(info->gpmc_irq_count);
699	enable_irq(info->gpmc_irq_fifo);
700
701	/* waiting for write to complete */
702	wait_for_completion(&info->comp);
703
704	/* wait for data to flushed-out before reset the prefetch */
705	tim = 0;
706	limit = (loops_per_jiffy *  msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
707	do {
708		val = readl(info->reg.gpmc_prefetch_status);
709		val = PREFETCH_STATUS_COUNT(val);
710		cpu_relax();
711	} while (val && (tim++ < limit));
712
713	/* disable and stop the PFPW engine */
714	omap_prefetch_reset(info->gpmc_cs, info);
715	return;
716
717out_copy:
718	if (info->nand.options & NAND_BUSWIDTH_16)
719		omap_write_buf16(mtd, buf, len);
720	else
721		omap_write_buf8(mtd, buf, len);
722}
723
724/**
725 * gen_true_ecc - This function will generate true ECC value
726 * @ecc_buf: buffer to store ecc code
727 *
728 * This generated true ECC value can be used when correcting
729 * data read from NAND flash memory core
730 */
731static void gen_true_ecc(u8 *ecc_buf)
732{
733	u32 tmp = ecc_buf[0] | (ecc_buf[1] << 16) |
734		((ecc_buf[2] & 0xF0) << 20) | ((ecc_buf[2] & 0x0F) << 8);
735
736	ecc_buf[0] = ~(P64o(tmp) | P64e(tmp) | P32o(tmp) | P32e(tmp) |
737			P16o(tmp) | P16e(tmp) | P8o(tmp) | P8e(tmp));
738	ecc_buf[1] = ~(P1024o(tmp) | P1024e(tmp) | P512o(tmp) | P512e(tmp) |
739			P256o(tmp) | P256e(tmp) | P128o(tmp) | P128e(tmp));
740	ecc_buf[2] = ~(P4o(tmp) | P4e(tmp) | P2o(tmp) | P2e(tmp) | P1o(tmp) |
741			P1e(tmp) | P2048o(tmp) | P2048e(tmp));
742}
743
744/**
745 * omap_compare_ecc - Detect (2 bits) and correct (1 bit) error in data
746 * @ecc_data1:  ecc code from nand spare area
747 * @ecc_data2:  ecc code from hardware register obtained from hardware ecc
748 * @page_data:  page data
749 *
750 * This function compares two ECC's and indicates if there is an error.
751 * If the error can be corrected it will be corrected to the buffer.
752 * If there is no error, %0 is returned. If there is an error but it
753 * was corrected, %1 is returned. Otherwise, %-1 is returned.
754 */
755static int omap_compare_ecc(u8 *ecc_data1,	/* read from NAND memory */
756			    u8 *ecc_data2,	/* read from register */
757			    u8 *page_data)
758{
759	uint	i;
760	u8	tmp0_bit[8], tmp1_bit[8], tmp2_bit[8];
761	u8	comp0_bit[8], comp1_bit[8], comp2_bit[8];
762	u8	ecc_bit[24];
763	u8	ecc_sum = 0;
764	u8	find_bit = 0;
765	uint	find_byte = 0;
766	int	isEccFF;
767
768	isEccFF = ((*(u32 *)ecc_data1 & 0xFFFFFF) == 0xFFFFFF);
769
770	gen_true_ecc(ecc_data1);
771	gen_true_ecc(ecc_data2);
772
773	for (i = 0; i <= 2; i++) {
774		*(ecc_data1 + i) = ~(*(ecc_data1 + i));
775		*(ecc_data2 + i) = ~(*(ecc_data2 + i));
776	}
777
778	for (i = 0; i < 8; i++) {
779		tmp0_bit[i]     = *ecc_data1 % 2;
780		*ecc_data1	= *ecc_data1 / 2;
781	}
782
783	for (i = 0; i < 8; i++) {
784		tmp1_bit[i]	 = *(ecc_data1 + 1) % 2;
785		*(ecc_data1 + 1) = *(ecc_data1 + 1) / 2;
786	}
787
788	for (i = 0; i < 8; i++) {
789		tmp2_bit[i]	 = *(ecc_data1 + 2) % 2;
790		*(ecc_data1 + 2) = *(ecc_data1 + 2) / 2;
791	}
792
793	for (i = 0; i < 8; i++) {
794		comp0_bit[i]     = *ecc_data2 % 2;
795		*ecc_data2       = *ecc_data2 / 2;
796	}
797
798	for (i = 0; i < 8; i++) {
799		comp1_bit[i]     = *(ecc_data2 + 1) % 2;
800		*(ecc_data2 + 1) = *(ecc_data2 + 1) / 2;
801	}
802
803	for (i = 0; i < 8; i++) {
804		comp2_bit[i]     = *(ecc_data2 + 2) % 2;
805		*(ecc_data2 + 2) = *(ecc_data2 + 2) / 2;
806	}
807
808	for (i = 0; i < 6; i++)
809		ecc_bit[i] = tmp2_bit[i + 2] ^ comp2_bit[i + 2];
810
811	for (i = 0; i < 8; i++)
812		ecc_bit[i + 6] = tmp0_bit[i] ^ comp0_bit[i];
813
814	for (i = 0; i < 8; i++)
815		ecc_bit[i + 14] = tmp1_bit[i] ^ comp1_bit[i];
816
817	ecc_bit[22] = tmp2_bit[0] ^ comp2_bit[0];
818	ecc_bit[23] = tmp2_bit[1] ^ comp2_bit[1];
819
820	for (i = 0; i < 24; i++)
821		ecc_sum += ecc_bit[i];
822
823	switch (ecc_sum) {
824	case 0:
825		/* Not reached because this function is not called if
826		 *  ECC values are equal
827		 */
828		return 0;
829
830	case 1:
831		/* Uncorrectable error */
832		pr_debug("ECC UNCORRECTED_ERROR 1\n");
833		return -1;
834
835	case 11:
836		/* UN-Correctable error */
837		pr_debug("ECC UNCORRECTED_ERROR B\n");
838		return -1;
839
840	case 12:
841		/* Correctable error */
842		find_byte = (ecc_bit[23] << 8) +
843			    (ecc_bit[21] << 7) +
844			    (ecc_bit[19] << 6) +
845			    (ecc_bit[17] << 5) +
846			    (ecc_bit[15] << 4) +
847			    (ecc_bit[13] << 3) +
848			    (ecc_bit[11] << 2) +
849			    (ecc_bit[9]  << 1) +
850			    ecc_bit[7];
851
852		find_bit = (ecc_bit[5] << 2) + (ecc_bit[3] << 1) + ecc_bit[1];
853
854		pr_debug("Correcting single bit ECC error at offset: "
855				"%d, bit: %d\n", find_byte, find_bit);
856
857		page_data[find_byte] ^= (1 << find_bit);
858
859		return 1;
860	default:
861		if (isEccFF) {
862			if (ecc_data2[0] == 0 &&
863			    ecc_data2[1] == 0 &&
864			    ecc_data2[2] == 0)
865				return 0;
866		}
867		pr_debug("UNCORRECTED_ERROR default\n");
868		return -1;
869	}
870}
871
872/**
873 * omap_correct_data - Compares the ECC read with HW generated ECC
874 * @mtd: MTD device structure
875 * @dat: page data
876 * @read_ecc: ecc read from nand flash
877 * @calc_ecc: ecc read from HW ECC registers
878 *
879 * Compares the ecc read from nand spare area with ECC registers values
880 * and if ECC's mismatched, it will call 'omap_compare_ecc' for error
881 * detection and correction. If there are no errors, %0 is returned. If
882 * there were errors and all of the errors were corrected, the number of
883 * corrected errors is returned. If uncorrectable errors exist, %-1 is
884 * returned.
885 */
886static int omap_correct_data(struct mtd_info *mtd, u_char *dat,
887				u_char *read_ecc, u_char *calc_ecc)
888{
889	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
890							mtd);
891	int blockCnt = 0, i = 0, ret = 0;
892	int stat = 0;
893
894	/* Ex NAND_ECC_HW12_2048 */
895	if ((info->nand.ecc.mode == NAND_ECC_HW) &&
896			(info->nand.ecc.size  == 2048))
897		blockCnt = 4;
898	else
899		blockCnt = 1;
900
901	for (i = 0; i < blockCnt; i++) {
902		if (memcmp(read_ecc, calc_ecc, 3) != 0) {
903			ret = omap_compare_ecc(read_ecc, calc_ecc, dat);
904			if (ret < 0)
905				return ret;
906			/* keep track of the number of corrected errors */
907			stat += ret;
908		}
909		read_ecc += 3;
910		calc_ecc += 3;
911		dat      += 512;
912	}
913	return stat;
914}
915
916/**
917 * omap_calcuate_ecc - Generate non-inverted ECC bytes.
918 * @mtd: MTD device structure
919 * @dat: The pointer to data on which ecc is computed
920 * @ecc_code: The ecc_code buffer
921 *
922 * Using noninverted ECC can be considered ugly since writing a blank
923 * page ie. padding will clear the ECC bytes. This is no problem as long
924 * nobody is trying to write data on the seemingly unused page. Reading
925 * an erased page will produce an ECC mismatch between generated and read
926 * ECC bytes that has to be dealt with separately.
927 */
928static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
929				u_char *ecc_code)
930{
931	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
932							mtd);
933	u32 val;
934
935	val = readl(info->reg.gpmc_ecc_config);
936	if (((val >> ECC_CONFIG_CS_SHIFT) & CS_MASK) != info->gpmc_cs)
937		return -EINVAL;
938
939	/* read ecc result */
940	val = readl(info->reg.gpmc_ecc1_result);
941	*ecc_code++ = val;          /* P128e, ..., P1e */
942	*ecc_code++ = val >> 16;    /* P128o, ..., P1o */
943	/* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
944	*ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
945
946	return 0;
947}
948
949/**
950 * omap_enable_hwecc - This function enables the hardware ecc functionality
951 * @mtd: MTD device structure
952 * @mode: Read/Write mode
953 */
954static void omap_enable_hwecc(struct mtd_info *mtd, int mode)
955{
956	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
957							mtd);
958	struct nand_chip *chip = mtd->priv;
959	unsigned int dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
960	u32 val;
961
962	/* clear ecc and enable bits */
963	val = ECCCLEAR | ECC1;
964	writel(val, info->reg.gpmc_ecc_control);
965
966	/* program ecc and result sizes */
967	val = ((((info->nand.ecc.size >> 1) - 1) << ECCSIZE1_SHIFT) |
968			 ECC1RESULTSIZE);
969	writel(val, info->reg.gpmc_ecc_size_config);
970
971	switch (mode) {
972	case NAND_ECC_READ:
973	case NAND_ECC_WRITE:
974		writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
975		break;
976	case NAND_ECC_READSYN:
977		writel(ECCCLEAR, info->reg.gpmc_ecc_control);
978		break;
979	default:
980		dev_info(&info->pdev->dev,
981			"error: unrecognized Mode[%d]!\n", mode);
982		break;
983	}
984
985	/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
986	val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
987	writel(val, info->reg.gpmc_ecc_config);
988}
989
990/**
991 * omap_wait - wait until the command is done
992 * @mtd: MTD device structure
993 * @chip: NAND Chip structure
994 *
995 * Wait function is called during Program and erase operations and
996 * the way it is called from MTD layer, we should wait till the NAND
997 * chip is ready after the programming/erase operation has completed.
998 *
999 * Erase can take up to 400ms and program up to 20ms according to
1000 * general NAND and SmartMedia specs
1001 */
1002static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
1003{
1004	struct nand_chip *this = mtd->priv;
1005	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1006							mtd);
1007	unsigned long timeo = jiffies;
1008	int status, state = this->state;
1009
1010	if (state == FL_ERASING)
1011		timeo += msecs_to_jiffies(400);
1012	else
1013		timeo += msecs_to_jiffies(20);
1014
1015	writeb(NAND_CMD_STATUS & 0xFF, info->reg.gpmc_nand_command);
1016	while (time_before(jiffies, timeo)) {
1017		status = readb(info->reg.gpmc_nand_data);
1018		if (status & NAND_STATUS_READY)
1019			break;
1020		cond_resched();
1021	}
1022
1023	status = readb(info->reg.gpmc_nand_data);
1024	return status;
1025}
1026
1027/**
1028 * omap_dev_ready - calls the platform specific dev_ready function
1029 * @mtd: MTD device structure
1030 */
1031static int omap_dev_ready(struct mtd_info *mtd)
1032{
1033	unsigned int val = 0;
1034	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1035							mtd);
1036
1037	val = readl(info->reg.gpmc_status);
1038
1039	if ((val & 0x100) == 0x100) {
1040		return 1;
1041	} else {
1042		return 0;
1043	}
1044}
1045
1046/**
1047 * omap_enable_hwecc_bch - Program GPMC to perform BCH ECC calculation
1048 * @mtd: MTD device structure
1049 * @mode: Read/Write mode
1050 *
1051 * When using BCH with SW correction (i.e. no ELM), sector size is set
1052 * to 512 bytes and we use BCH_WRAPMODE_6 wrapping mode
1053 * for both reading and writing with:
1054 * eccsize0 = 0  (no additional protected byte in spare area)
1055 * eccsize1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
1056 */
1057static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd, int mode)
1058{
1059	unsigned int bch_type;
1060	unsigned int dev_width, nsectors;
1061	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1062						   mtd);
1063	enum omap_ecc ecc_opt = info->ecc_opt;
1064	struct nand_chip *chip = mtd->priv;
1065	u32 val, wr_mode;
1066	unsigned int ecc_size1, ecc_size0;
1067
1068	/* GPMC configurations for calculating ECC */
1069	switch (ecc_opt) {
1070	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1071		bch_type = 0;
1072		nsectors = 1;
1073		wr_mode	  = BCH_WRAPMODE_6;
1074		ecc_size0 = BCH_ECC_SIZE0;
1075		ecc_size1 = BCH_ECC_SIZE1;
1076		break;
1077	case OMAP_ECC_BCH4_CODE_HW:
1078		bch_type = 0;
1079		nsectors = chip->ecc.steps;
1080		if (mode == NAND_ECC_READ) {
1081			wr_mode	  = BCH_WRAPMODE_1;
1082			ecc_size0 = BCH4R_ECC_SIZE0;
1083			ecc_size1 = BCH4R_ECC_SIZE1;
1084		} else {
1085			wr_mode   = BCH_WRAPMODE_6;
1086			ecc_size0 = BCH_ECC_SIZE0;
1087			ecc_size1 = BCH_ECC_SIZE1;
1088		}
1089		break;
1090	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1091		bch_type = 1;
1092		nsectors = 1;
1093		wr_mode	  = BCH_WRAPMODE_6;
1094		ecc_size0 = BCH_ECC_SIZE0;
1095		ecc_size1 = BCH_ECC_SIZE1;
1096		break;
1097	case OMAP_ECC_BCH8_CODE_HW:
1098		bch_type = 1;
1099		nsectors = chip->ecc.steps;
1100		if (mode == NAND_ECC_READ) {
1101			wr_mode	  = BCH_WRAPMODE_1;
1102			ecc_size0 = BCH8R_ECC_SIZE0;
1103			ecc_size1 = BCH8R_ECC_SIZE1;
1104		} else {
1105			wr_mode   = BCH_WRAPMODE_6;
1106			ecc_size0 = BCH_ECC_SIZE0;
1107			ecc_size1 = BCH_ECC_SIZE1;
1108		}
1109		break;
1110	case OMAP_ECC_BCH16_CODE_HW:
1111		bch_type = 0x2;
1112		nsectors = chip->ecc.steps;
1113		if (mode == NAND_ECC_READ) {
1114			wr_mode	  = 0x01;
1115			ecc_size0 = 52; /* ECC bits in nibbles per sector */
1116			ecc_size1 = 0;  /* non-ECC bits in nibbles per sector */
1117		} else {
1118			wr_mode	  = 0x01;
1119			ecc_size0 = 0;  /* extra bits in nibbles per sector */
1120			ecc_size1 = 52; /* OOB bits in nibbles per sector */
1121		}
1122		break;
1123	default:
1124		return;
1125	}
1126
1127	writel(ECC1, info->reg.gpmc_ecc_control);
1128
1129	/* Configure ecc size for BCH */
1130	val = (ecc_size1 << ECCSIZE1_SHIFT) | (ecc_size0 << ECCSIZE0_SHIFT);
1131	writel(val, info->reg.gpmc_ecc_size_config);
1132
1133	dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
1134
1135	/* BCH configuration */
1136	val = ((1                        << 16) | /* enable BCH */
1137	       (bch_type		 << 12) | /* BCH4/BCH8/BCH16 */
1138	       (wr_mode                  <<  8) | /* wrap mode */
1139	       (dev_width                <<  7) | /* bus width */
1140	       (((nsectors-1) & 0x7)     <<  4) | /* number of sectors */
1141	       (info->gpmc_cs            <<  1) | /* ECC CS */
1142	       (0x1));                            /* enable ECC */
1143
1144	writel(val, info->reg.gpmc_ecc_config);
1145
1146	/* Clear ecc and enable bits */
1147	writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
1148}
1149
1150static u8  bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
1151static u8  bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2,
1152				0x97, 0x79, 0xe5, 0x24, 0xb5};
1153
1154/**
1155 * omap_calculate_ecc_bch - Generate bytes of ECC bytes
1156 * @mtd:	MTD device structure
1157 * @dat:	The pointer to data on which ecc is computed
1158 * @ecc_code:	The ecc_code buffer
1159 *
1160 * Support calculating of BCH4/8 ecc vectors for the page
1161 */
1162static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
1163					const u_char *dat, u_char *ecc_calc)
1164{
1165	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1166						   mtd);
1167	int eccbytes	= info->nand.ecc.bytes;
1168	struct gpmc_nand_regs	*gpmc_regs = &info->reg;
1169	u8 *ecc_code;
1170	unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4;
1171	u32 val;
1172	int i, j;
1173
1174	nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
1175	for (i = 0; i < nsectors; i++) {
1176		ecc_code = ecc_calc;
1177		switch (info->ecc_opt) {
1178		case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1179		case OMAP_ECC_BCH8_CODE_HW:
1180			bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1181			bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1182			bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
1183			bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
1184			*ecc_code++ = (bch_val4 & 0xFF);
1185			*ecc_code++ = ((bch_val3 >> 24) & 0xFF);
1186			*ecc_code++ = ((bch_val3 >> 16) & 0xFF);
1187			*ecc_code++ = ((bch_val3 >> 8) & 0xFF);
1188			*ecc_code++ = (bch_val3 & 0xFF);
1189			*ecc_code++ = ((bch_val2 >> 24) & 0xFF);
1190			*ecc_code++ = ((bch_val2 >> 16) & 0xFF);
1191			*ecc_code++ = ((bch_val2 >> 8) & 0xFF);
1192			*ecc_code++ = (bch_val2 & 0xFF);
1193			*ecc_code++ = ((bch_val1 >> 24) & 0xFF);
1194			*ecc_code++ = ((bch_val1 >> 16) & 0xFF);
1195			*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
1196			*ecc_code++ = (bch_val1 & 0xFF);
1197			break;
1198		case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1199		case OMAP_ECC_BCH4_CODE_HW:
1200			bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
1201			bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
1202			*ecc_code++ = ((bch_val2 >> 12) & 0xFF);
1203			*ecc_code++ = ((bch_val2 >> 4) & 0xFF);
1204			*ecc_code++ = ((bch_val2 & 0xF) << 4) |
1205				((bch_val1 >> 28) & 0xF);
1206			*ecc_code++ = ((bch_val1 >> 20) & 0xFF);
1207			*ecc_code++ = ((bch_val1 >> 12) & 0xFF);
1208			*ecc_code++ = ((bch_val1 >> 4) & 0xFF);
1209			*ecc_code++ = ((bch_val1 & 0xF) << 4);
1210			break;
1211		case OMAP_ECC_BCH16_CODE_HW:
1212			val = readl(gpmc_regs->gpmc_bch_result6[i]);
1213			ecc_code[0]  = ((val >>  8) & 0xFF);
1214			ecc_code[1]  = ((val >>  0) & 0xFF);
1215			val = readl(gpmc_regs->gpmc_bch_result5[i]);
1216			ecc_code[2]  = ((val >> 24) & 0xFF);
1217			ecc_code[3]  = ((val >> 16) & 0xFF);
1218			ecc_code[4]  = ((val >>  8) & 0xFF);
1219			ecc_code[5]  = ((val >>  0) & 0xFF);
1220			val = readl(gpmc_regs->gpmc_bch_result4[i]);
1221			ecc_code[6]  = ((val >> 24) & 0xFF);
1222			ecc_code[7]  = ((val >> 16) & 0xFF);
1223			ecc_code[8]  = ((val >>  8) & 0xFF);
1224			ecc_code[9]  = ((val >>  0) & 0xFF);
1225			val = readl(gpmc_regs->gpmc_bch_result3[i]);
1226			ecc_code[10] = ((val >> 24) & 0xFF);
1227			ecc_code[11] = ((val >> 16) & 0xFF);
1228			ecc_code[12] = ((val >>  8) & 0xFF);
1229			ecc_code[13] = ((val >>  0) & 0xFF);
1230			val = readl(gpmc_regs->gpmc_bch_result2[i]);
1231			ecc_code[14] = ((val >> 24) & 0xFF);
1232			ecc_code[15] = ((val >> 16) & 0xFF);
1233			ecc_code[16] = ((val >>  8) & 0xFF);
1234			ecc_code[17] = ((val >>  0) & 0xFF);
1235			val = readl(gpmc_regs->gpmc_bch_result1[i]);
1236			ecc_code[18] = ((val >> 24) & 0xFF);
1237			ecc_code[19] = ((val >> 16) & 0xFF);
1238			ecc_code[20] = ((val >>  8) & 0xFF);
1239			ecc_code[21] = ((val >>  0) & 0xFF);
1240			val = readl(gpmc_regs->gpmc_bch_result0[i]);
1241			ecc_code[22] = ((val >> 24) & 0xFF);
1242			ecc_code[23] = ((val >> 16) & 0xFF);
1243			ecc_code[24] = ((val >>  8) & 0xFF);
1244			ecc_code[25] = ((val >>  0) & 0xFF);
1245			break;
1246		default:
1247			return -EINVAL;
1248		}
1249
1250		/* ECC scheme specific syndrome customizations */
1251		switch (info->ecc_opt) {
1252		case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1253			/* Add constant polynomial to remainder, so that
1254			 * ECC of blank pages results in 0x0 on reading back */
1255			for (j = 0; j < eccbytes; j++)
1256				ecc_calc[j] ^= bch4_polynomial[j];
1257			break;
1258		case OMAP_ECC_BCH4_CODE_HW:
1259			/* Set  8th ECC byte as 0x0 for ROM compatibility */
1260			ecc_calc[eccbytes - 1] = 0x0;
1261			break;
1262		case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1263			/* Add constant polynomial to remainder, so that
1264			 * ECC of blank pages results in 0x0 on reading back */
1265			for (j = 0; j < eccbytes; j++)
1266				ecc_calc[j] ^= bch8_polynomial[j];
1267			break;
1268		case OMAP_ECC_BCH8_CODE_HW:
1269			/* Set 14th ECC byte as 0x0 for ROM compatibility */
1270			ecc_calc[eccbytes - 1] = 0x0;
1271			break;
1272		case OMAP_ECC_BCH16_CODE_HW:
1273			break;
1274		default:
1275			return -EINVAL;
1276		}
1277
1278	ecc_calc += eccbytes;
1279	}
1280
1281	return 0;
1282}
1283
1284/**
1285 * erased_sector_bitflips - count bit flips
1286 * @data:	data sector buffer
1287 * @oob:	oob buffer
1288 * @info:	omap_nand_info
1289 *
1290 * Check the bit flips in erased page falls below correctable level.
1291 * If falls below, report the page as erased with correctable bit
1292 * flip, else report as uncorrectable page.
1293 */
1294static int erased_sector_bitflips(u_char *data, u_char *oob,
1295		struct omap_nand_info *info)
1296{
1297	int flip_bits = 0, i;
1298
1299	for (i = 0; i < info->nand.ecc.size; i++) {
1300		flip_bits += hweight8(~data[i]);
1301		if (flip_bits > info->nand.ecc.strength)
1302			return 0;
1303	}
1304
1305	for (i = 0; i < info->nand.ecc.bytes - 1; i++) {
1306		flip_bits += hweight8(~oob[i]);
1307		if (flip_bits > info->nand.ecc.strength)
1308			return 0;
1309	}
1310
1311	/*
1312	 * Bit flips falls in correctable level.
1313	 * Fill data area with 0xFF
1314	 */
1315	if (flip_bits) {
1316		memset(data, 0xFF, info->nand.ecc.size);
1317		memset(oob, 0xFF, info->nand.ecc.bytes);
1318	}
1319
1320	return flip_bits;
1321}
1322
1323/**
1324 * omap_elm_correct_data - corrects page data area in case error reported
1325 * @mtd:	MTD device structure
1326 * @data:	page data
1327 * @read_ecc:	ecc read from nand flash
1328 * @calc_ecc:	ecc read from HW ECC registers
1329 *
1330 * Calculated ecc vector reported as zero in case of non-error pages.
1331 * In case of non-zero ecc vector, first filter out erased-pages, and
1332 * then process data via ELM to detect bit-flips.
1333 */
1334static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data,
1335				u_char *read_ecc, u_char *calc_ecc)
1336{
1337	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1338			mtd);
1339	struct nand_ecc_ctrl *ecc = &info->nand.ecc;
1340	int eccsteps = info->nand.ecc.steps;
1341	int i , j, stat = 0;
1342	int eccflag, actual_eccbytes;
1343	struct elm_errorvec err_vec[ERROR_VECTOR_MAX];
1344	u_char *ecc_vec = calc_ecc;
1345	u_char *spare_ecc = read_ecc;
1346	u_char *erased_ecc_vec;
1347	u_char *buf;
1348	int bitflip_count;
1349	bool is_error_reported = false;
1350	u32 bit_pos, byte_pos, error_max, pos;
1351	int err;
1352
1353	switch (info->ecc_opt) {
1354	case OMAP_ECC_BCH4_CODE_HW:
1355		/* omit  7th ECC byte reserved for ROM code compatibility */
1356		actual_eccbytes = ecc->bytes - 1;
1357		erased_ecc_vec = bch4_vector;
1358		break;
1359	case OMAP_ECC_BCH8_CODE_HW:
1360		/* omit 14th ECC byte reserved for ROM code compatibility */
1361		actual_eccbytes = ecc->bytes - 1;
1362		erased_ecc_vec = bch8_vector;
1363		break;
1364	case OMAP_ECC_BCH16_CODE_HW:
1365		actual_eccbytes = ecc->bytes;
1366		erased_ecc_vec = bch16_vector;
1367		break;
1368	default:
1369		dev_err(&info->pdev->dev, "invalid driver configuration\n");
1370		return -EINVAL;
1371	}
1372
1373	/* Initialize elm error vector to zero */
1374	memset(err_vec, 0, sizeof(err_vec));
1375
1376	for (i = 0; i < eccsteps ; i++) {
1377		eccflag = 0;	/* initialize eccflag */
1378
1379		/*
1380		 * Check any error reported,
1381		 * In case of error, non zero ecc reported.
1382		 */
1383		for (j = 0; j < actual_eccbytes; j++) {
1384			if (calc_ecc[j] != 0) {
1385				eccflag = 1; /* non zero ecc, error present */
1386				break;
1387			}
1388		}
1389
1390		if (eccflag == 1) {
1391			if (memcmp(calc_ecc, erased_ecc_vec,
1392						actual_eccbytes) == 0) {
1393				/*
1394				 * calc_ecc[] matches pattern for ECC(all 0xff)
1395				 * so this is definitely an erased-page
1396				 */
1397			} else {
1398				buf = &data[info->nand.ecc.size * i];
1399				/*
1400				 * count number of 0-bits in read_buf.
1401				 * This check can be removed once a similar
1402				 * check is introduced in generic NAND driver
1403				 */
1404				bitflip_count = erased_sector_bitflips(
1405						buf, read_ecc, info);
1406				if (bitflip_count) {
1407					/*
1408					 * number of 0-bits within ECC limits
1409					 * So this may be an erased-page
1410					 */
1411					stat += bitflip_count;
1412				} else {
1413					/*
1414					 * Too many 0-bits. It may be a
1415					 * - programmed-page, OR
1416					 * - erased-page with many bit-flips
1417					 * So this page requires check by ELM
1418					 */
1419					err_vec[i].error_reported = true;
1420					is_error_reported = true;
1421				}
1422			}
1423		}
1424
1425		/* Update the ecc vector */
1426		calc_ecc += ecc->bytes;
1427		read_ecc += ecc->bytes;
1428	}
1429
1430	/* Check if any error reported */
1431	if (!is_error_reported)
1432		return stat;
1433
1434	/* Decode BCH error using ELM module */
1435	elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec);
1436
1437	err = 0;
1438	for (i = 0; i < eccsteps; i++) {
1439		if (err_vec[i].error_uncorrectable) {
1440			dev_err(&info->pdev->dev,
1441				"uncorrectable bit-flips found\n");
1442			err = -EBADMSG;
1443		} else if (err_vec[i].error_reported) {
1444			for (j = 0; j < err_vec[i].error_count; j++) {
1445				switch (info->ecc_opt) {
1446				case OMAP_ECC_BCH4_CODE_HW:
1447					/* Add 4 bits to take care of padding */
1448					pos = err_vec[i].error_loc[j] +
1449						BCH4_BIT_PAD;
1450					break;
1451				case OMAP_ECC_BCH8_CODE_HW:
1452				case OMAP_ECC_BCH16_CODE_HW:
1453					pos = err_vec[i].error_loc[j];
1454					break;
1455				default:
1456					return -EINVAL;
1457				}
1458				error_max = (ecc->size + actual_eccbytes) * 8;
1459				/* Calculate bit position of error */
1460				bit_pos = pos % 8;
1461
1462				/* Calculate byte position of error */
1463				byte_pos = (error_max - pos - 1) / 8;
1464
1465				if (pos < error_max) {
1466					if (byte_pos < 512) {
1467						pr_debug("bitflip@dat[%d]=%x\n",
1468						     byte_pos, data[byte_pos]);
1469						data[byte_pos] ^= 1 << bit_pos;
1470					} else {
1471						pr_debug("bitflip@oob[%d]=%x\n",
1472							(byte_pos - 512),
1473						     spare_ecc[byte_pos - 512]);
1474						spare_ecc[byte_pos - 512] ^=
1475							1 << bit_pos;
1476					}
1477				} else {
1478					dev_err(&info->pdev->dev,
1479						"invalid bit-flip @ %d:%d\n",
1480						byte_pos, bit_pos);
1481					err = -EBADMSG;
1482				}
1483			}
1484		}
1485
1486		/* Update number of correctable errors */
1487		stat += err_vec[i].error_count;
1488
1489		/* Update page data with sector size */
1490		data += ecc->size;
1491		spare_ecc += ecc->bytes;
1492	}
1493
1494	return (err) ? err : stat;
1495}
1496
1497/**
1498 * omap_write_page_bch - BCH ecc based write page function for entire page
1499 * @mtd:		mtd info structure
1500 * @chip:		nand chip info structure
1501 * @buf:		data buffer
1502 * @oob_required:	must write chip->oob_poi to OOB
1503 *
1504 * Custom write page method evolved to support multi sector writing in one shot
1505 */
1506static int omap_write_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
1507				  const uint8_t *buf, int oob_required)
1508{
1509	int i;
1510	uint8_t *ecc_calc = chip->buffers->ecccalc;
1511	uint32_t *eccpos = chip->ecc.layout->eccpos;
1512
1513	/* Enable GPMC ecc engine */
1514	chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
1515
1516	/* Write data */
1517	chip->write_buf(mtd, buf, mtd->writesize);
1518
1519	/* Update ecc vector from GPMC result registers */
1520	chip->ecc.calculate(mtd, buf, &ecc_calc[0]);
1521
1522	for (i = 0; i < chip->ecc.total; i++)
1523		chip->oob_poi[eccpos[i]] = ecc_calc[i];
1524
1525	/* Write ecc vector to OOB area */
1526	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
1527	return 0;
1528}
1529
1530/**
1531 * omap_read_page_bch - BCH ecc based page read function for entire page
1532 * @mtd:		mtd info structure
1533 * @chip:		nand chip info structure
1534 * @buf:		buffer to store read data
1535 * @oob_required:	caller requires OOB data read to chip->oob_poi
1536 * @page:		page number to read
1537 *
1538 * For BCH ecc scheme, GPMC used for syndrome calculation and ELM module
1539 * used for error correction.
1540 * Custom method evolved to support ELM error correction & multi sector
1541 * reading. On reading page data area is read along with OOB data with
1542 * ecc engine enabled. ecc vector updated after read of OOB data.
1543 * For non error pages ecc vector reported as zero.
1544 */
1545static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
1546				uint8_t *buf, int oob_required, int page)
1547{
1548	uint8_t *ecc_calc = chip->buffers->ecccalc;
1549	uint8_t *ecc_code = chip->buffers->ecccode;
1550	uint32_t *eccpos = chip->ecc.layout->eccpos;
1551	uint8_t *oob = &chip->oob_poi[eccpos[0]];
1552	uint32_t oob_pos = mtd->writesize + chip->ecc.layout->eccpos[0];
1553	int stat;
1554	unsigned int max_bitflips = 0;
1555
1556	/* Enable GPMC ecc engine */
1557	chip->ecc.hwctl(mtd, NAND_ECC_READ);
1558
1559	/* Read data */
1560	chip->read_buf(mtd, buf, mtd->writesize);
1561
1562	/* Read oob bytes */
1563	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1);
1564	chip->read_buf(mtd, oob, chip->ecc.total);
1565
1566	/* Calculate ecc bytes */
1567	chip->ecc.calculate(mtd, buf, ecc_calc);
1568
1569	memcpy(ecc_code, &chip->oob_poi[eccpos[0]], chip->ecc.total);
1570
1571	stat = chip->ecc.correct(mtd, buf, ecc_code, ecc_calc);
1572
1573	if (stat < 0) {
1574		mtd->ecc_stats.failed++;
1575	} else {
1576		mtd->ecc_stats.corrected += stat;
1577		max_bitflips = max_t(unsigned int, max_bitflips, stat);
1578	}
1579
1580	return max_bitflips;
1581}
1582
1583/**
1584 * is_elm_present - checks for presence of ELM module by scanning DT nodes
1585 * @omap_nand_info: NAND device structure containing platform data
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				 struct omap_nand_platform_data	*pdata)
1610{
1611	bool ecc_needs_bch, ecc_needs_omap_bch, ecc_needs_elm;
1612
1613	switch (info->ecc_opt) {
1614	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1615	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1616		ecc_needs_omap_bch = false;
1617		ecc_needs_bch = true;
1618		ecc_needs_elm = false;
1619		break;
1620	case OMAP_ECC_BCH4_CODE_HW:
1621	case OMAP_ECC_BCH8_CODE_HW:
1622	case OMAP_ECC_BCH16_CODE_HW:
1623		ecc_needs_omap_bch = true;
1624		ecc_needs_bch = false;
1625		ecc_needs_elm = true;
1626		break;
1627	default:
1628		ecc_needs_omap_bch = false;
1629		ecc_needs_bch = false;
1630		ecc_needs_elm = false;
1631		break;
1632	}
1633
1634	if (ecc_needs_bch && !IS_ENABLED(CONFIG_MTD_NAND_ECC_BCH)) {
1635		dev_err(&info->pdev->dev,
1636			"CONFIG_MTD_NAND_ECC_BCH not enabled\n");
1637		return false;
1638	}
1639	if (ecc_needs_omap_bch && !IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH)) {
1640		dev_err(&info->pdev->dev,
1641			"CONFIG_MTD_NAND_OMAP_BCH not enabled\n");
1642		return false;
1643	}
1644	if (ecc_needs_elm && !is_elm_present(info, pdata->elm_of_node)) {
1645		dev_err(&info->pdev->dev, "ELM not available\n");
1646		return false;
1647	}
1648
1649	return true;
1650}
1651
1652static int omap_nand_probe(struct platform_device *pdev)
1653{
1654	struct omap_nand_info		*info;
1655	struct omap_nand_platform_data	*pdata;
1656	struct mtd_info			*mtd;
1657	struct nand_chip		*nand_chip;
1658	struct nand_ecclayout		*ecclayout;
1659	int				err;
1660	int				i;
1661	dma_cap_mask_t			mask;
1662	unsigned			sig;
1663	unsigned			oob_index;
1664	struct resource			*res;
1665	struct mtd_part_parser_data	ppdata = {};
1666
1667	pdata = dev_get_platdata(&pdev->dev);
1668	if (pdata == NULL) {
1669		dev_err(&pdev->dev, "platform data missing\n");
1670		return -ENODEV;
1671	}
1672
1673	info = devm_kzalloc(&pdev->dev, sizeof(struct omap_nand_info),
1674				GFP_KERNEL);
1675	if (!info)
1676		return -ENOMEM;
1677
1678	platform_set_drvdata(pdev, info);
1679
1680	info->pdev		= pdev;
1681	info->gpmc_cs		= pdata->cs;
1682	info->reg		= pdata->reg;
1683	info->of_node		= pdata->of_node;
1684	info->ecc_opt		= pdata->ecc_opt;
1685	mtd			= &info->mtd;
1686	mtd->priv		= &info->nand;
1687	mtd->name		= dev_name(&pdev->dev);
1688	mtd->owner		= THIS_MODULE;
1689	nand_chip		= &info->nand;
1690	nand_chip->ecc.priv	= NULL;
1691
1692	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1693	nand_chip->IO_ADDR_R = devm_ioremap_resource(&pdev->dev, res);
1694	if (IS_ERR(nand_chip->IO_ADDR_R))
1695		return PTR_ERR(nand_chip->IO_ADDR_R);
1696
1697	info->phys_base = res->start;
1698
1699	nand_chip->controller = &omap_gpmc_controller;
1700
1701	nand_chip->IO_ADDR_W = nand_chip->IO_ADDR_R;
1702	nand_chip->cmd_ctrl  = omap_hwcontrol;
1703
1704	/*
1705	 * If RDY/BSY line is connected to OMAP then use the omap ready
1706	 * function and the generic nand_wait function which reads the status
1707	 * register after monitoring the RDY/BSY line. Otherwise use a standard
1708	 * chip delay which is slightly more than tR (AC Timing) of the NAND
1709	 * device and read status register until you get a failure or success
1710	 */
1711	if (pdata->dev_ready) {
1712		nand_chip->dev_ready = omap_dev_ready;
1713		nand_chip->chip_delay = 0;
1714	} else {
1715		nand_chip->waitfunc = omap_wait;
1716		nand_chip->chip_delay = 50;
1717	}
1718
1719	if (pdata->flash_bbt)
1720		nand_chip->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
1721	else
1722		nand_chip->options |= NAND_SKIP_BBTSCAN;
1723
1724	/* scan NAND device connected to chip controller */
1725	nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16;
1726	if (nand_scan_ident(mtd, 1, NULL)) {
1727		dev_err(&info->pdev->dev, "scan failed, may be bus-width mismatch\n");
1728		err = -ENXIO;
1729		goto return_error;
1730	}
1731
1732	/* re-populate low-level callbacks based on xfer modes */
1733	switch (pdata->xfer_type) {
1734	case NAND_OMAP_PREFETCH_POLLED:
1735		nand_chip->read_buf   = omap_read_buf_pref;
1736		nand_chip->write_buf  = omap_write_buf_pref;
1737		break;
1738
1739	case NAND_OMAP_POLLED:
1740		/* Use nand_base defaults for {read,write}_buf */
1741		break;
1742
1743	case NAND_OMAP_PREFETCH_DMA:
1744		dma_cap_zero(mask);
1745		dma_cap_set(DMA_SLAVE, mask);
1746		sig = OMAP24XX_DMA_GPMC;
1747		info->dma = dma_request_channel(mask, omap_dma_filter_fn, &sig);
1748		if (!info->dma) {
1749			dev_err(&pdev->dev, "DMA engine request failed\n");
1750			err = -ENXIO;
1751			goto return_error;
1752		} else {
1753			struct dma_slave_config cfg;
1754
1755			memset(&cfg, 0, sizeof(cfg));
1756			cfg.src_addr = info->phys_base;
1757			cfg.dst_addr = info->phys_base;
1758			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1759			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1760			cfg.src_maxburst = 16;
1761			cfg.dst_maxburst = 16;
1762			err = dmaengine_slave_config(info->dma, &cfg);
1763			if (err) {
1764				dev_err(&pdev->dev, "DMA engine slave config failed: %d\n",
1765					err);
1766				goto return_error;
1767			}
1768			nand_chip->read_buf   = omap_read_buf_dma_pref;
1769			nand_chip->write_buf  = omap_write_buf_dma_pref;
1770		}
1771		break;
1772
1773	case NAND_OMAP_PREFETCH_IRQ:
1774		info->gpmc_irq_fifo = platform_get_irq(pdev, 0);
1775		if (info->gpmc_irq_fifo <= 0) {
1776			dev_err(&pdev->dev, "error getting fifo irq\n");
1777			err = -ENODEV;
1778			goto return_error;
1779		}
1780		err = devm_request_irq(&pdev->dev, info->gpmc_irq_fifo,
1781					omap_nand_irq, IRQF_SHARED,
1782					"gpmc-nand-fifo", info);
1783		if (err) {
1784			dev_err(&pdev->dev, "requesting irq(%d) error:%d",
1785						info->gpmc_irq_fifo, err);
1786			info->gpmc_irq_fifo = 0;
1787			goto return_error;
1788		}
1789
1790		info->gpmc_irq_count = platform_get_irq(pdev, 1);
1791		if (info->gpmc_irq_count <= 0) {
1792			dev_err(&pdev->dev, "error getting count irq\n");
1793			err = -ENODEV;
1794			goto return_error;
1795		}
1796		err = devm_request_irq(&pdev->dev, info->gpmc_irq_count,
1797					omap_nand_irq, IRQF_SHARED,
1798					"gpmc-nand-count", info);
1799		if (err) {
1800			dev_err(&pdev->dev, "requesting irq(%d) error:%d",
1801						info->gpmc_irq_count, err);
1802			info->gpmc_irq_count = 0;
1803			goto return_error;
1804		}
1805
1806		nand_chip->read_buf  = omap_read_buf_irq_pref;
1807		nand_chip->write_buf = omap_write_buf_irq_pref;
1808
1809		break;
1810
1811	default:
1812		dev_err(&pdev->dev,
1813			"xfer_type(%d) not supported!\n", pdata->xfer_type);
1814		err = -EINVAL;
1815		goto return_error;
1816	}
1817
1818	if (!omap2_nand_ecc_check(info, pdata)) {
1819		err = -EINVAL;
1820		goto return_error;
1821	}
1822
1823	/* populate MTD interface based on ECC scheme */
1824	ecclayout		= &info->oobinfo;
1825	switch (info->ecc_opt) {
1826	case OMAP_ECC_HAM1_CODE_SW:
1827		nand_chip->ecc.mode = NAND_ECC_SOFT;
1828		break;
1829
1830	case OMAP_ECC_HAM1_CODE_HW:
1831		pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n");
1832		nand_chip->ecc.mode             = NAND_ECC_HW;
1833		nand_chip->ecc.bytes            = 3;
1834		nand_chip->ecc.size             = 512;
1835		nand_chip->ecc.strength         = 1;
1836		nand_chip->ecc.calculate        = omap_calculate_ecc;
1837		nand_chip->ecc.hwctl            = omap_enable_hwecc;
1838		nand_chip->ecc.correct          = omap_correct_data;
1839		/* define ECC layout */
1840		ecclayout->eccbytes		= nand_chip->ecc.bytes *
1841							(mtd->writesize /
1842							nand_chip->ecc.size);
1843		if (nand_chip->options & NAND_BUSWIDTH_16)
1844			oob_index		= BADBLOCK_MARKER_LENGTH;
1845		else
1846			oob_index		= 1;
1847		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
1848			ecclayout->eccpos[i]	= oob_index;
1849		/* no reserved-marker in ecclayout for this ecc-scheme */
1850		ecclayout->oobfree->offset	=
1851				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
1852		break;
1853
1854	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
1855		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW\n");
1856		nand_chip->ecc.mode		= NAND_ECC_HW;
1857		nand_chip->ecc.size		= 512;
1858		nand_chip->ecc.bytes		= 7;
1859		nand_chip->ecc.strength		= 4;
1860		nand_chip->ecc.hwctl		= omap_enable_hwecc_bch;
1861		nand_chip->ecc.correct		= nand_bch_correct_data;
1862		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;
1863		/* define ECC layout */
1864		ecclayout->eccbytes		= nand_chip->ecc.bytes *
1865							(mtd->writesize /
1866							nand_chip->ecc.size);
1867		oob_index			= BADBLOCK_MARKER_LENGTH;
1868		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++) {
1869			ecclayout->eccpos[i] = oob_index;
1870			if (((i + 1) % nand_chip->ecc.bytes) == 0)
1871				oob_index++;
1872		}
1873		/* include reserved-marker in ecclayout->oobfree calculation */
1874		ecclayout->oobfree->offset	= 1 +
1875				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
1876		/* software bch library is used for locating errors */
1877		nand_chip->ecc.priv		= nand_bch_init(mtd,
1878							nand_chip->ecc.size,
1879							nand_chip->ecc.bytes,
1880							&ecclayout);
1881		if (!nand_chip->ecc.priv) {
1882			dev_err(&info->pdev->dev, "unable to use BCH library\n");
1883			err = -EINVAL;
1884			goto return_error;
1885		}
1886		break;
1887
1888	case OMAP_ECC_BCH4_CODE_HW:
1889		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW ECC scheme\n");
1890		nand_chip->ecc.mode		= NAND_ECC_HW;
1891		nand_chip->ecc.size		= 512;
1892		/* 14th bit is kept reserved for ROM-code compatibility */
1893		nand_chip->ecc.bytes		= 7 + 1;
1894		nand_chip->ecc.strength		= 4;
1895		nand_chip->ecc.hwctl		= omap_enable_hwecc_bch;
1896		nand_chip->ecc.correct		= omap_elm_correct_data;
1897		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;
1898		nand_chip->ecc.read_page	= omap_read_page_bch;
1899		nand_chip->ecc.write_page	= omap_write_page_bch;
1900		/* define ECC layout */
1901		ecclayout->eccbytes		= nand_chip->ecc.bytes *
1902							(mtd->writesize /
1903							nand_chip->ecc.size);
1904		oob_index			= BADBLOCK_MARKER_LENGTH;
1905		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
1906			ecclayout->eccpos[i]	= oob_index;
1907		/* reserved marker already included in ecclayout->eccbytes */
1908		ecclayout->oobfree->offset	=
1909				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
1910
1911		err = elm_config(info->elm_dev, BCH4_ECC,
1912				 info->mtd.writesize / nand_chip->ecc.size,
1913				 nand_chip->ecc.size, nand_chip->ecc.bytes);
1914		if (err < 0)
1915			goto return_error;
1916		break;
1917
1918	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
1919		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
1920		nand_chip->ecc.mode		= NAND_ECC_HW;
1921		nand_chip->ecc.size		= 512;
1922		nand_chip->ecc.bytes		= 13;
1923		nand_chip->ecc.strength		= 8;
1924		nand_chip->ecc.hwctl		= omap_enable_hwecc_bch;
1925		nand_chip->ecc.correct		= nand_bch_correct_data;
1926		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;
1927		/* define ECC layout */
1928		ecclayout->eccbytes		= nand_chip->ecc.bytes *
1929							(mtd->writesize /
1930							nand_chip->ecc.size);
1931		oob_index			= BADBLOCK_MARKER_LENGTH;
1932		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++) {
1933			ecclayout->eccpos[i] = oob_index;
1934			if (((i + 1) % nand_chip->ecc.bytes) == 0)
1935				oob_index++;
1936		}
1937		/* include reserved-marker in ecclayout->oobfree calculation */
1938		ecclayout->oobfree->offset	= 1 +
1939				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
1940		/* software bch library is used for locating errors */
1941		nand_chip->ecc.priv		= nand_bch_init(mtd,
1942							nand_chip->ecc.size,
1943							nand_chip->ecc.bytes,
1944							&ecclayout);
1945		if (!nand_chip->ecc.priv) {
1946			dev_err(&info->pdev->dev, "unable to use BCH library\n");
1947			err = -EINVAL;
1948			goto return_error;
1949		}
1950		break;
1951
1952	case OMAP_ECC_BCH8_CODE_HW:
1953		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme\n");
1954		nand_chip->ecc.mode		= NAND_ECC_HW;
1955		nand_chip->ecc.size		= 512;
1956		/* 14th bit is kept reserved for ROM-code compatibility */
1957		nand_chip->ecc.bytes		= 13 + 1;
1958		nand_chip->ecc.strength		= 8;
1959		nand_chip->ecc.hwctl		= omap_enable_hwecc_bch;
1960		nand_chip->ecc.correct		= omap_elm_correct_data;
1961		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;
1962		nand_chip->ecc.read_page	= omap_read_page_bch;
1963		nand_chip->ecc.write_page	= omap_write_page_bch;
1964
1965		err = elm_config(info->elm_dev, BCH8_ECC,
1966				 info->mtd.writesize / nand_chip->ecc.size,
1967				 nand_chip->ecc.size, nand_chip->ecc.bytes);
1968		if (err < 0)
1969			goto return_error;
1970
1971		/* define ECC layout */
1972		ecclayout->eccbytes		= nand_chip->ecc.bytes *
1973							(mtd->writesize /
1974							nand_chip->ecc.size);
1975		oob_index			= BADBLOCK_MARKER_LENGTH;
1976		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
1977			ecclayout->eccpos[i]	= oob_index;
1978		/* reserved marker already included in ecclayout->eccbytes */
1979		ecclayout->oobfree->offset	=
1980				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
1981		break;
1982
1983	case OMAP_ECC_BCH16_CODE_HW:
1984		pr_info("using OMAP_ECC_BCH16_CODE_HW ECC scheme\n");
1985		nand_chip->ecc.mode		= NAND_ECC_HW;
1986		nand_chip->ecc.size		= 512;
1987		nand_chip->ecc.bytes		= 26;
1988		nand_chip->ecc.strength		= 16;
1989		nand_chip->ecc.hwctl		= omap_enable_hwecc_bch;
1990		nand_chip->ecc.correct		= omap_elm_correct_data;
1991		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;
1992		nand_chip->ecc.read_page	= omap_read_page_bch;
1993		nand_chip->ecc.write_page	= omap_write_page_bch;
1994
1995		err = elm_config(info->elm_dev, BCH16_ECC,
1996				 info->mtd.writesize / nand_chip->ecc.size,
1997				 nand_chip->ecc.size, nand_chip->ecc.bytes);
1998		if (err < 0)
1999			goto return_error;
2000
2001		/* define ECC layout */
2002		ecclayout->eccbytes		= nand_chip->ecc.bytes *
2003							(mtd->writesize /
2004							nand_chip->ecc.size);
2005		oob_index			= BADBLOCK_MARKER_LENGTH;
2006		for (i = 0; i < ecclayout->eccbytes; i++, oob_index++)
2007			ecclayout->eccpos[i]	= oob_index;
2008		/* reserved marker already included in ecclayout->eccbytes */
2009		ecclayout->oobfree->offset	=
2010				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
2011		break;
2012	default:
2013		dev_err(&info->pdev->dev, "invalid or unsupported ECC scheme\n");
2014		err = -EINVAL;
2015		goto return_error;
2016	}
2017
2018	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW)
2019		goto scan_tail;
2020
2021	/* all OOB bytes from oobfree->offset till end off OOB are free */
2022	ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset;
2023	/* check if NAND device's OOB is enough to store ECC signatures */
2024	if (mtd->oobsize < (ecclayout->eccbytes + BADBLOCK_MARKER_LENGTH)) {
2025		dev_err(&info->pdev->dev,
2026			"not enough OOB bytes required = %d, available=%d\n",
2027			ecclayout->eccbytes, mtd->oobsize);
2028		err = -EINVAL;
2029		goto return_error;
2030	}
2031	nand_chip->ecc.layout = ecclayout;
2032
2033scan_tail:
2034	/* second phase scan */
2035	if (nand_scan_tail(mtd)) {
2036		err = -ENXIO;
2037		goto return_error;
2038	}
2039
2040	ppdata.of_node = pdata->of_node;
2041	mtd_device_parse_register(mtd, NULL, &ppdata, pdata->parts,
2042				  pdata->nr_parts);
2043
2044	platform_set_drvdata(pdev, mtd);
2045
2046	return 0;
2047
2048return_error:
2049	if (info->dma)
2050		dma_release_channel(info->dma);
2051	if (nand_chip->ecc.priv) {
2052		nand_bch_free(nand_chip->ecc.priv);
2053		nand_chip->ecc.priv = NULL;
2054	}
2055	return err;
2056}
2057
2058static int omap_nand_remove(struct platform_device *pdev)
2059{
2060	struct mtd_info *mtd = platform_get_drvdata(pdev);
2061	struct nand_chip *nand_chip = mtd->priv;
2062	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
2063							mtd);
2064	if (nand_chip->ecc.priv) {
2065		nand_bch_free(nand_chip->ecc.priv);
2066		nand_chip->ecc.priv = NULL;
2067	}
2068	if (info->dma)
2069		dma_release_channel(info->dma);
2070	nand_release(mtd);
2071	return 0;
2072}
2073
2074static struct platform_driver omap_nand_driver = {
2075	.probe		= omap_nand_probe,
2076	.remove		= omap_nand_remove,
2077	.driver		= {
2078		.name	= DRIVER_NAME,
2079	},
2080};
2081
2082module_platform_driver(omap_nand_driver);
2083
2084MODULE_ALIAS("platform:" DRIVER_NAME);
2085MODULE_LICENSE("GPL");
2086MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");
2087