xref: /openbmc/u-boot/include/linux/mtd/nand.h (revision 33b1d3f4)
1 /*
2  *  linux/include/linux/mtd/nand.h
3  *
4  *  Copyright (c) 2000 David Woodhouse <dwmw2@infradead.org>
5  *                     Steven J. Hill <sjhill@realitydiluted.com>
6  *		       Thomas Gleixner <tglx@linutronix.de>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * Info:
13  *	Contains standard defines and IDs for NAND flash devices
14  *
15  * Changelog:
16  *	See git changelog.
17  */
18 #ifndef __LINUX_MTD_NAND_H
19 #define __LINUX_MTD_NAND_H
20 
21 /* XXX U-BOOT XXX */
22 #if 0
23 #include <linux/wait.h>
24 #include <linux/spinlock.h>
25 #include <linux/mtd/mtd.h>
26 #endif
27 
28 #include "config.h"
29 
30 #include "linux/mtd/compat.h"
31 #include "linux/mtd/mtd.h"
32 #include "linux/mtd/bbm.h"
33 
34 
35 struct mtd_info;
36 /* Scan and identify a NAND device */
37 extern int nand_scan (struct mtd_info *mtd, int max_chips);
38 /* Separate phases of nand_scan(), allowing board driver to intervene
39  * and override command or ECC setup according to flash type */
40 extern int nand_scan_ident(struct mtd_info *mtd, int max_chips);
41 extern int nand_scan_tail(struct mtd_info *mtd);
42 
43 /* Free resources held by the NAND device */
44 extern void nand_release (struct mtd_info *mtd);
45 
46 /* Internal helper for board drivers which need to override command function */
47 extern void nand_wait_ready(struct mtd_info *mtd);
48 
49 /* This constant declares the max. oobsize / page, which
50  * is supported now. If you add a chip with bigger oobsize/page
51  * adjust this accordingly.
52  */
53 #define NAND_MAX_OOBSIZE	128
54 #define NAND_MAX_PAGESIZE	4096
55 
56 /*
57  * Constants for hardware specific CLE/ALE/NCE function
58  *
59  * These are bits which can be or'ed to set/clear multiple
60  * bits in one go.
61  */
62 /* Select the chip by setting nCE to low */
63 #define NAND_NCE		0x01
64 /* Select the command latch by setting CLE to high */
65 #define NAND_CLE		0x02
66 /* Select the address latch by setting ALE to high */
67 #define NAND_ALE		0x04
68 
69 #define NAND_CTRL_CLE		(NAND_NCE | NAND_CLE)
70 #define NAND_CTRL_ALE		(NAND_NCE | NAND_ALE)
71 #define NAND_CTRL_CHANGE	0x80
72 
73 /*
74  * Standard NAND flash commands
75  */
76 #define NAND_CMD_READ0		0
77 #define NAND_CMD_READ1		1
78 #define NAND_CMD_RNDOUT		5
79 #define NAND_CMD_PAGEPROG	0x10
80 #define NAND_CMD_READOOB	0x50
81 #define NAND_CMD_ERASE1		0x60
82 #define NAND_CMD_STATUS		0x70
83 #define NAND_CMD_STATUS_MULTI	0x71
84 #define NAND_CMD_SEQIN		0x80
85 #define NAND_CMD_RNDIN		0x85
86 #define NAND_CMD_READID		0x90
87 #define NAND_CMD_ERASE2		0xd0
88 #define NAND_CMD_RESET		0xff
89 
90 /* Extended commands for large page devices */
91 #define NAND_CMD_READSTART	0x30
92 #define NAND_CMD_RNDOUTSTART	0xE0
93 #define NAND_CMD_CACHEDPROG	0x15
94 
95 /* Extended commands for AG-AND device */
96 /*
97  * Note: the command for NAND_CMD_DEPLETE1 is really 0x00 but
98  *       there is no way to distinguish that from NAND_CMD_READ0
99  *       until the remaining sequence of commands has been completed
100  *       so add a high order bit and mask it off in the command.
101  */
102 #define NAND_CMD_DEPLETE1	0x100
103 #define NAND_CMD_DEPLETE2	0x38
104 #define NAND_CMD_STATUS_MULTI	0x71
105 #define NAND_CMD_STATUS_ERROR	0x72
106 /* multi-bank error status (banks 0-3) */
107 #define NAND_CMD_STATUS_ERROR0	0x73
108 #define NAND_CMD_STATUS_ERROR1	0x74
109 #define NAND_CMD_STATUS_ERROR2	0x75
110 #define NAND_CMD_STATUS_ERROR3	0x76
111 #define NAND_CMD_STATUS_RESET	0x7f
112 #define NAND_CMD_STATUS_CLEAR	0xff
113 
114 #define NAND_CMD_NONE		-1
115 
116 /* Status bits */
117 #define NAND_STATUS_FAIL	0x01
118 #define NAND_STATUS_FAIL_N1	0x02
119 #define NAND_STATUS_TRUE_READY	0x20
120 #define NAND_STATUS_READY	0x40
121 #define NAND_STATUS_WP		0x80
122 
123 /*
124  * Constants for ECC_MODES
125  */
126 typedef enum {
127 	NAND_ECC_NONE,
128 	NAND_ECC_SOFT,
129 	NAND_ECC_HW,
130 	NAND_ECC_HW_SYNDROME,
131 } nand_ecc_modes_t;
132 
133 /*
134  * Constants for Hardware ECC
135  */
136 /* Reset Hardware ECC for read */
137 #define NAND_ECC_READ		0
138 /* Reset Hardware ECC for write */
139 #define NAND_ECC_WRITE		1
140 /* Enable Hardware ECC before syndrom is read back from flash */
141 #define NAND_ECC_READSYN	2
142 
143 /* Bit mask for flags passed to do_nand_read_ecc */
144 #define NAND_GET_DEVICE		0x80
145 
146 
147 /* Option constants for bizarre disfunctionality and real
148 *  features
149 */
150 /* Chip can not auto increment pages */
151 #define NAND_NO_AUTOINCR	0x00000001
152 /* Buswitdh is 16 bit */
153 #define NAND_BUSWIDTH_16	0x00000002
154 /* Device supports partial programming without padding */
155 #define NAND_NO_PADDING		0x00000004
156 /* Chip has cache program function */
157 #define NAND_CACHEPRG		0x00000008
158 /* Chip has copy back function */
159 #define NAND_COPYBACK		0x00000010
160 /* AND Chip which has 4 banks and a confusing page / block
161  * assignment. See Renesas datasheet for further information */
162 #define NAND_IS_AND		0x00000020
163 /* Chip has a array of 4 pages which can be read without
164  * additional ready /busy waits */
165 #define NAND_4PAGE_ARRAY	0x00000040
166 /* Chip requires that BBT is periodically rewritten to prevent
167  * bits from adjacent blocks from 'leaking' in altering data.
168  * This happens with the Renesas AG-AND chips, possibly others.  */
169 #define BBT_AUTO_REFRESH	0x00000080
170 /* Chip does not require ready check on read. True
171  * for all large page devices, as they do not support
172  * autoincrement.*/
173 #define NAND_NO_READRDY		0x00000100
174 /* Chip does not allow subpage writes */
175 #define NAND_NO_SUBPAGE_WRITE	0x00000200
176 
177 
178 /* Options valid for Samsung large page devices */
179 #define NAND_SAMSUNG_LP_OPTIONS \
180 	(NAND_NO_PADDING | NAND_CACHEPRG | NAND_COPYBACK)
181 
182 /* Macros to identify the above */
183 #define NAND_CANAUTOINCR(chip) (!(chip->options & NAND_NO_AUTOINCR))
184 #define NAND_MUST_PAD(chip) (!(chip->options & NAND_NO_PADDING))
185 #define NAND_HAS_CACHEPROG(chip) ((chip->options & NAND_CACHEPRG))
186 #define NAND_HAS_COPYBACK(chip) ((chip->options & NAND_COPYBACK))
187 /* Large page NAND with SOFT_ECC should support subpage reads */
188 #define NAND_SUBPAGE_READ(chip) ((chip->ecc.mode == NAND_ECC_SOFT) \
189 					&& (chip->page_shift > 9))
190 
191 /* Mask to zero out the chip options, which come from the id table */
192 #define NAND_CHIPOPTIONS_MSK	(0x0000ffff & ~NAND_NO_AUTOINCR)
193 
194 /* Non chip related options */
195 /* Use a flash based bad block table. This option is passed to the
196  * default bad block table function. */
197 #define NAND_USE_FLASH_BBT	0x00010000
198 /* This option skips the bbt scan during initialization. */
199 #define NAND_SKIP_BBTSCAN	0x00020000
200 /* This option is defined if the board driver allocates its own buffers
201    (e.g. because it needs them DMA-coherent */
202 #define NAND_OWN_BUFFERS	0x00040000
203 /* Options set by nand scan */
204 /* bbt has already been read */
205 #define NAND_BBT_SCANNED	0x40000000
206 /* Nand scan has allocated controller struct */
207 #define NAND_CONTROLLER_ALLOC	0x80000000
208 
209 /* Cell info constants */
210 #define NAND_CI_CHIPNR_MSK	0x03
211 #define NAND_CI_CELLTYPE_MSK	0x0C
212 
213 /* Keep gcc happy */
214 struct nand_chip;
215 
216 /**
217  * struct nand_hw_control - Control structure for hardware controller (e.g ECC generator) shared among independent devices
218  * @lock:               protection lock
219  * @active:		the mtd device which holds the controller currently
220  * @wq:			wait queue to sleep on if a NAND operation is in progress
221  *                      used instead of the per chip wait queue when a hw controller is available
222  */
223 struct nand_hw_control {
224 /* XXX U-BOOT XXX */
225 #if 0
226 	spinlock_t	 lock;
227 	wait_queue_head_t wq;
228 #endif
229 	struct nand_chip *active;
230 };
231 
232 /**
233  * struct nand_ecc_ctrl - Control structure for ecc
234  * @mode:	ecc mode
235  * @steps:	number of ecc steps per page
236  * @size:	data bytes per ecc step
237  * @bytes:	ecc bytes per step
238  * @total:	total number of ecc bytes per page
239  * @prepad:	padding information for syndrome based ecc generators
240  * @postpad:	padding information for syndrome based ecc generators
241  * @layout:	ECC layout control struct pointer
242  * @hwctl:	function to control hardware ecc generator. Must only
243  *		be provided if an hardware ECC is available
244  * @calculate:	function for ecc calculation or readback from ecc hardware
245  * @correct:	function for ecc correction, matching to ecc generator (sw/hw)
246  * @read_page_raw:	function to read a raw page without ECC
247  * @write_page_raw:	function to write a raw page without ECC
248  * @read_page:	function to read a page according to the ecc generator requirements
249  * @write_page:	function to write a page according to the ecc generator requirements
250  * @read_oob:	function to read chip OOB data
251  * @write_oob:	function to write chip OOB data
252  */
253 struct nand_ecc_ctrl {
254 	nand_ecc_modes_t	mode;
255 	int			steps;
256 	int			size;
257 	int			bytes;
258 	int			total;
259 	int			prepad;
260 	int			postpad;
261 	struct nand_ecclayout	*layout;
262 	void			(*hwctl)(struct mtd_info *mtd, int mode);
263 	int			(*calculate)(struct mtd_info *mtd,
264 					     const uint8_t *dat,
265 					     uint8_t *ecc_code);
266 	int			(*correct)(struct mtd_info *mtd, uint8_t *dat,
267 					   uint8_t *read_ecc,
268 					   uint8_t *calc_ecc);
269 	int			(*read_page_raw)(struct mtd_info *mtd,
270 						 struct nand_chip *chip,
271 						 uint8_t *buf);
272 	void			(*write_page_raw)(struct mtd_info *mtd,
273 						  struct nand_chip *chip,
274 						  const uint8_t *buf);
275 	int			(*read_page)(struct mtd_info *mtd,
276 					     struct nand_chip *chip,
277 					     uint8_t *buf);
278 	int			(*read_subpage)(struct mtd_info *mtd,
279 					     struct nand_chip *chip,
280 					     uint32_t offs, uint32_t len,
281 					     uint8_t *buf);
282 	void			(*write_page)(struct mtd_info *mtd,
283 					      struct nand_chip *chip,
284 					      const uint8_t *buf);
285 	int			(*read_oob)(struct mtd_info *mtd,
286 					    struct nand_chip *chip,
287 					    int page,
288 					    int sndcmd);
289 	int			(*write_oob)(struct mtd_info *mtd,
290 					     struct nand_chip *chip,
291 					     int page);
292 };
293 
294 /**
295  * struct nand_buffers - buffer structure for read/write
296  * @ecccalc:	buffer for calculated ecc
297  * @ecccode:	buffer for ecc read from flash
298  * @databuf:	buffer for data - dynamically sized
299  *
300  * Do not change the order of buffers. databuf and oobrbuf must be in
301  * consecutive order.
302  */
303 struct nand_buffers {
304 	uint8_t	ecccalc[NAND_MAX_OOBSIZE];
305 	uint8_t	ecccode[NAND_MAX_OOBSIZE];
306 	uint8_t databuf[NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE];
307 };
308 
309 /**
310  * struct nand_chip - NAND Private Flash Chip Data
311  * @IO_ADDR_R:		[BOARDSPECIFIC] address to read the 8 I/O lines of the flash device
312  * @IO_ADDR_W:		[BOARDSPECIFIC] address to write the 8 I/O lines of the flash device
313  * @read_byte:		[REPLACEABLE] read one byte from the chip
314  * @read_word:		[REPLACEABLE] read one word from the chip
315  * @write_buf:		[REPLACEABLE] write data from the buffer to the chip
316  * @read_buf:		[REPLACEABLE] read data from the chip into the buffer
317  * @verify_buf:		[REPLACEABLE] verify buffer contents against the chip data
318  * @select_chip:	[REPLACEABLE] select chip nr
319  * @block_bad:		[REPLACEABLE] check, if the block is bad
320  * @block_markbad:	[REPLACEABLE] mark the block bad
321  * @cmd_ctrl:		[BOARDSPECIFIC] hardwarespecific funtion for controlling
322  *			ALE/CLE/nCE. Also used to write command and address
323  * @dev_ready:		[BOARDSPECIFIC] hardwarespecific function for accesing device ready/busy line
324  *			If set to NULL no access to ready/busy is available and the ready/busy information
325  *			is read from the chip status register
326  * @cmdfunc:		[REPLACEABLE] hardwarespecific function for writing commands to the chip
327  * @waitfunc:		[REPLACEABLE] hardwarespecific function for wait on ready
328  * @ecc:		[BOARDSPECIFIC] ecc control ctructure
329  * @buffers:		buffer structure for read/write
330  * @hwcontrol:		platform-specific hardware control structure
331  * @ops:		oob operation operands
332  * @erase_cmd:		[INTERN] erase command write function, selectable due to AND support
333  * @scan_bbt:		[REPLACEABLE] function to scan bad block table
334  * @chip_delay:		[BOARDSPECIFIC] chip dependent delay for transfering data from array to read regs (tR)
335  * @wq:			[INTERN] wait queue to sleep on if a NAND operation is in progress
336  * @state:		[INTERN] the current state of the NAND device
337  * @oob_poi:		poison value buffer
338  * @page_shift:		[INTERN] number of address bits in a page (column address bits)
339  * @phys_erase_shift:	[INTERN] number of address bits in a physical eraseblock
340  * @bbt_erase_shift:	[INTERN] number of address bits in a bbt entry
341  * @chip_shift:		[INTERN] number of address bits in one chip
342  * @datbuf:		[INTERN] internal buffer for one page + oob
343  * @oobbuf:		[INTERN] oob buffer for one eraseblock
344  * @oobdirty:		[INTERN] indicates that oob_buf must be reinitialized
345  * @data_poi:		[INTERN] pointer to a data buffer
346  * @options:		[BOARDSPECIFIC] various chip options. They can partly be set to inform nand_scan about
347  *			special functionality. See the defines for further explanation
348  * @badblockpos:	[INTERN] position of the bad block marker in the oob area
349  * @cellinfo:		[INTERN] MLC/multichip data from chip ident
350  * @numchips:		[INTERN] number of physical chips
351  * @chipsize:		[INTERN] the size of one chip for multichip arrays
352  * @pagemask:		[INTERN] page number mask = number of (pages / chip) - 1
353  * @pagebuf:		[INTERN] holds the pagenumber which is currently in data_buf
354  * @subpagesize:	[INTERN] holds the subpagesize
355  * @ecclayout:		[REPLACEABLE] the default ecc placement scheme
356  * @bbt:		[INTERN] bad block table pointer
357  * @bbt_td:		[REPLACEABLE] bad block table descriptor for flash lookup
358  * @bbt_md:		[REPLACEABLE] bad block table mirror descriptor
359  * @badblock_pattern:	[REPLACEABLE] bad block scan pattern used for initial bad block scan
360  * @controller:		[REPLACEABLE] a pointer to a hardware controller structure
361  *			which is shared among multiple independend devices
362  * @priv:		[OPTIONAL] pointer to private chip date
363  * @errstat:		[OPTIONAL] hardware specific function to perform additional error status checks
364  *			(determine if errors are correctable)
365  * @write_page:		[REPLACEABLE] High-level page write function
366  */
367 
368 struct nand_chip {
369 	void  __iomem	*IO_ADDR_R;
370 	void  __iomem	*IO_ADDR_W;
371 
372 	uint8_t		(*read_byte)(struct mtd_info *mtd);
373 	u16		(*read_word)(struct mtd_info *mtd);
374 	void		(*write_buf)(struct mtd_info *mtd, const uint8_t *buf, int len);
375 	void		(*read_buf)(struct mtd_info *mtd, uint8_t *buf, int len);
376 	int		(*verify_buf)(struct mtd_info *mtd, const uint8_t *buf, int len);
377 	void		(*select_chip)(struct mtd_info *mtd, int chip);
378 	int		(*block_bad)(struct mtd_info *mtd, loff_t ofs, int getchip);
379 	int		(*block_markbad)(struct mtd_info *mtd, loff_t ofs);
380 	void		(*cmd_ctrl)(struct mtd_info *mtd, int dat,
381 				    unsigned int ctrl);
382 	int		(*dev_ready)(struct mtd_info *mtd);
383 	void		(*cmdfunc)(struct mtd_info *mtd, unsigned command, int column, int page_addr);
384 	int		(*waitfunc)(struct mtd_info *mtd, struct nand_chip *this);
385 	void		(*erase_cmd)(struct mtd_info *mtd, int page);
386 	int		(*scan_bbt)(struct mtd_info *mtd);
387 	int		(*errstat)(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page);
388 	int		(*write_page)(struct mtd_info *mtd, struct nand_chip *chip,
389 				      const uint8_t *buf, int page, int cached, int raw);
390 
391 	int		chip_delay;
392 	unsigned int	options;
393 
394 	int		page_shift;
395 	int		phys_erase_shift;
396 	int		bbt_erase_shift;
397 	int		chip_shift;
398 	int		numchips;
399 	unsigned long	chipsize;
400 	int		pagemask;
401 	int		pagebuf;
402 	int		subpagesize;
403 	uint8_t		cellinfo;
404 	int		badblockpos;
405 
406 	int 		state;
407 
408 	uint8_t		*oob_poi;
409 	struct nand_hw_control  *controller;
410 	struct nand_ecclayout	*ecclayout;
411 
412 	struct nand_ecc_ctrl ecc;
413 	struct nand_buffers *buffers;
414 
415 	struct nand_hw_control hwcontrol;
416 
417 	struct mtd_oob_ops ops;
418 
419 	uint8_t		*bbt;
420 	struct nand_bbt_descr	*bbt_td;
421 	struct nand_bbt_descr	*bbt_md;
422 
423 	struct nand_bbt_descr	*badblock_pattern;
424 
425 	void		*priv;
426 };
427 
428 /*
429  * NAND Flash Manufacturer ID Codes
430  */
431 #define NAND_MFR_TOSHIBA	0x98
432 #define NAND_MFR_SAMSUNG	0xec
433 #define NAND_MFR_FUJITSU	0x04
434 #define NAND_MFR_NATIONAL	0x8f
435 #define NAND_MFR_RENESAS	0x07
436 #define NAND_MFR_STMICRO	0x20
437 #define NAND_MFR_HYNIX		0xad
438 #define NAND_MFR_MICRON		0x2c
439 #define NAND_MFR_AMD		0x01
440 
441 /**
442  * struct nand_flash_dev - NAND Flash Device ID Structure
443  * @name:	Identify the device type
444  * @id:		device ID code
445  * @pagesize:	Pagesize in bytes. Either 256 or 512 or 0
446  *		If the pagesize is 0, then the real pagesize
447  *		and the eraseize are determined from the
448  *		extended id bytes in the chip
449  * @erasesize:	Size of an erase block in the flash device.
450  * @chipsize:	Total chipsize in Mega Bytes
451  * @options:	Bitfield to store chip relevant options
452  */
453 struct nand_flash_dev {
454 	char *name;
455 	int id;
456 	unsigned long pagesize;
457 	unsigned long chipsize;
458 	unsigned long erasesize;
459 	unsigned long options;
460 };
461 
462 /**
463  * struct nand_manufacturers - NAND Flash Manufacturer ID Structure
464  * @name:	Manufacturer name
465  * @id:		manufacturer ID code of device.
466 */
467 struct nand_manufacturers {
468 	int id;
469 	char * name;
470 };
471 
472 extern struct nand_flash_dev nand_flash_ids[];
473 extern struct nand_manufacturers nand_manuf_ids[];
474 
475 extern int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
476 extern int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
477 extern int nand_default_bbt(struct mtd_info *mtd);
478 extern int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt);
479 extern int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
480 			   int allowbbt);
481 extern int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len,
482 			size_t * retlen, uint8_t * buf);
483 
484 /*
485 * Constants for oob configuration
486 */
487 #define NAND_SMALL_BADBLOCK_POS		5
488 #define NAND_LARGE_BADBLOCK_POS		0
489 
490 /**
491  * struct platform_nand_chip - chip level device structure
492  * @nr_chips:		max. number of chips to scan for
493  * @chip_offset:	chip number offset
494  * @nr_partitions:	number of partitions pointed to by partitions (or zero)
495  * @partitions:		mtd partition list
496  * @chip_delay:		R/B delay value in us
497  * @options:		Option flags, e.g. 16bit buswidth
498  * @ecclayout:		ecc layout info structure
499  * @part_probe_types:	NULL-terminated array of probe types
500  * @priv:		hardware controller specific settings
501  */
502 struct platform_nand_chip {
503 	int			nr_chips;
504 	int			chip_offset;
505 	int			nr_partitions;
506 	struct mtd_partition	*partitions;
507 	struct nand_ecclayout	*ecclayout;
508 	int			chip_delay;
509 	unsigned int		options;
510 	const char		**part_probe_types;
511 	void			*priv;
512 };
513 
514 /**
515  * struct platform_nand_ctrl - controller level device structure
516  * @hwcontrol:		platform specific hardware control structure
517  * @dev_ready:		platform specific function to read ready/busy pin
518  * @select_chip:	platform specific chip select function
519  * @cmd_ctrl:		platform specific function for controlling
520  *			ALE/CLE/nCE. Also used to write command and address
521  * @priv:		private data to transport driver specific settings
522  *
523  * All fields are optional and depend on the hardware driver requirements
524  */
525 struct platform_nand_ctrl {
526 	void		(*hwcontrol)(struct mtd_info *mtd, int cmd);
527 	int		(*dev_ready)(struct mtd_info *mtd);
528 	void		(*select_chip)(struct mtd_info *mtd, int chip);
529 	void		(*cmd_ctrl)(struct mtd_info *mtd, int dat,
530 				    unsigned int ctrl);
531 	void		*priv;
532 };
533 
534 /**
535  * struct platform_nand_data - container structure for platform-specific data
536  * @chip:		chip level chip structure
537  * @ctrl:		controller level device structure
538  */
539 struct platform_nand_data {
540 	struct platform_nand_chip	chip;
541 	struct platform_nand_ctrl	ctrl;
542 };
543 
544 /* Some helpers to access the data structures */
545 static inline
546 struct platform_nand_chip *get_platform_nandchip(struct mtd_info *mtd)
547 {
548 	struct nand_chip *chip = mtd->priv;
549 
550 	return chip->priv;
551 }
552 
553 #endif /* __LINUX_MTD_NAND_H */
554