include/linux/mtd/nand.h

   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 */