include/linux/mtd/mtd.h

   1 /*
   2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  *
  18  */
  19
  20 #ifndef __MTD_MTD_H__
  21 #define __MTD_MTD_H__
  22
  23 #include <linux/types.h>
  24 #include <linux/uio.h>
  25 #include <linux/notifier.h>
  26 #include <linux/device.h>
  27
  28 #include <mtd/mtd-abi.h>
  29
  30 #include <asm/div64.h>
  31
  32 #define MTD_CHAR_MAJOR 90
  33 #define MTD_BLOCK_MAJOR 31
  34
  35 #define MTD_ERASE_PENDING       0x01
  36 #define MTD_ERASING             0x02
  37 #define MTD_ERASE_SUSPEND       0x04
  38 #define MTD_ERASE_DONE          0x08
  39 #define MTD_ERASE_FAILED        0x10
  40
  41 #define MTD_FAIL_ADDR_UNKNOWN -1LL
  42
  43 /*
  44  * If the erase fails, fail_addr might indicate exactly which block failed. If
  45  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
  46  * or was not specific to any particular block.
  47  */
  48 struct erase_info {
  49         struct mtd_info *mtd;
  50         uint64_t addr;
  51         uint64_t len;
  52         uint64_t fail_addr;
  53         u_long time;
  54         u_long retries;
  55         unsigned dev;
  56         unsigned cell;
  57         void (*callback) (struct erase_info *self);
  58         u_long priv;
  59         u_char state;
  60         struct erase_info *next;
  61 };
  62
  63 struct mtd_erase_region_info {
  64         uint64_t offset;                /* At which this region starts, from the beginning of the MTD */
  65         uint32_t erasesize;             /* For this region */
  66         uint32_t numblocks;             /* Number of blocks of erasesize in this region */
  67         unsigned long *lockmap;         /* If keeping bitmap of locks */
  68 };
  69
  70 /*
  71  * oob operation modes
  72  *
  73  * MTD_OOB_PLACE:       oob data are placed at the given offset
  74  * MTD_OOB_AUTO:        oob data are automatically placed at the free areas
  75  *                      which are defined by the ecclayout
  76  * MTD_OOB_RAW:         mode to read oob and data without doing ECC checking
  77  */
  78 typedef enum {
  79         MTD_OOB_PLACE,
  80         MTD_OOB_AUTO,
  81         MTD_OOB_RAW,
  82 } mtd_oob_mode_t;
  83
  84 /**
  85  * struct mtd_oob_ops - oob operation operands
  86  * @mode:       operation mode
  87  *
  88  * @len:        number of data bytes to write/read
  89  *
  90  * @retlen:     number of data bytes written/read
  91  *
  92  * @ooblen:     number of oob bytes to write/read
  93  * @oobretlen:  number of oob bytes written/read
  94  * @ooboffs:    offset of oob data in the oob area (only relevant when
  95  *              mode = MTD_OOB_PLACE)
  96  * @datbuf:     data buffer - if NULL only oob data are read/written
  97  * @oobbuf:     oob data buffer
  98  *
  99  * Note, it is allowed to read more than one OOB area at one go, but not write.
 100  * The interface assumes that the OOB write requests program only one page's
 101  * OOB area.
 102  */
 103 struct mtd_oob_ops {
 104         mtd_oob_mode_t  mode;
 105         size_t          len;
 106         size_t          retlen;
 107         size_t          ooblen;
 108         size_t          oobretlen;
 109         uint32_t        ooboffs;
 110         uint8_t         *datbuf;
 111         uint8_t         *oobbuf;
 112 };
 113
 114 #define MTD_MAX_OOBFREE_ENTRIES_LARGE   32
 115 #define MTD_MAX_ECCPOS_ENTRIES_LARGE    448
 116 /*
 117  * Internal ECC layout control structure. For historical reasons, there is a
 118  * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
 119  * for export to user-space via the ECCGETLAYOUT ioctl.
 120  * nand_ecclayout should be expandable in the future simply by the above macros.
 121  */
 122 struct nand_ecclayout {
 123         __u32 eccbytes;
 124         __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
 125         __u32 oobavail;
 126         struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
 127 };
 128
 129 struct module;  /* only needed for owner field in mtd_info */
 130
 131 struct mtd_info {
 132         u_char type;
 133         uint32_t flags;
 134         uint64_t size;   // Total size of the MTD
 135
 136         /* "Major" erase size for the device. Naïve users may take this
 137          * to be the only erase size available, or may use the more detailed
 138          * information below if they desire
 139          */
 140         uint32_t erasesize;
 141         /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
 142          * though individual bits can be cleared), in case of NAND flash it is
 143          * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
 144          * it is of ECC block size, etc. It is illegal to have writesize = 0.
 145          * Any driver registering a struct mtd_info must ensure a writesize of
 146          * 1 or larger.
 147          */
 148         uint32_t writesize;
 149
 150         /*
 151          * Size of the write buffer used by the MTD. MTD devices having a write
 152          * buffer can write multiple writesize chunks at a time. E.g. while
 153          * writing 4 * writesize bytes to a device with 2 * writesize bytes
 154          * buffer the MTD driver can (but doesn't have to) do 2 writesize
 155          * operations, but not 4. Currently, all NANDs have writebufsize
 156          * equivalent to writesize (NAND page size). Some NOR flashes do have
 157          * writebufsize greater than writesize.
 158          */
 159         uint32_t writebufsize;
 160
 161         uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 162         uint32_t oobavail;  // Available OOB bytes per block
 163
 164         /*
 165          * If erasesize is a power of 2 then the shift is stored in
 166          * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
 167          */
 168         unsigned int erasesize_shift;
 169         unsigned int writesize_shift;
 170         /* Masks based on erasesize_shift and writesize_shift */
 171         unsigned int erasesize_mask;
 172         unsigned int writesize_mask;
 173
 174         // Kernel-only stuff starts here.
 175         const char *name;
 176         int index;
 177
 178         /* ECC layout structure pointer - read only! */
 179         struct nand_ecclayout *ecclayout;
 180
 181         /* Data for variable erase regions. If numeraseregions is zero,
 182          * it means that the whole device has erasesize as given above.
 183          */
 184         int numeraseregions;
 185         struct mtd_erase_region_info *eraseregions;
 186
 187         /*
 188          * Erase is an asynchronous operation.  Device drivers are supposed
 189          * to call instr->callback() whenever the operation completes, even
 190          * if it completes with a failure.
 191          * Callers are supposed to pass a callback function and wait for it
 192          * to be called before writing to the block.
 193          */
 194         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 195
 196         /* This stuff for eXecute-In-Place */
 197         /* phys is optional and may be set to NULL */
 198         int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
 199                         size_t *retlen, void **virt, resource_size_t *phys);
 200
 201         /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 202         void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 203
 204         /* Allow NOMMU mmap() to directly map the device (if not NULL)
 205          * - return the address to which the offset maps
 206          * - return -ENOSYS to indicate refusal to do the mapping
 207          */
 208         unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
 209                                             unsigned long len,
 210                                             unsigned long offset,
 211                                             unsigned long flags);
 212
 213         /* Backing device capabilities for this device
 214          * - provides mmap capabilities
 215          */
 216         struct backing_dev_info *backing_dev_info;
 217
 218
 219         int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 220         int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 221
 222         /* In blackbox flight recorder like scenarios we want to make successful
 223            writes in interrupt context. panic_write() is only intended to be
 224            called when its known the kernel is about to panic and we need the
 225            write to succeed. Since the kernel is not going to be running for much
 226            longer, this function can break locks and delay to ensure the write
 227            succeeds (but not sleep). */
 228
 229         int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 230
 231         int (*read_oob) (struct mtd_info *mtd, loff_t from,
 232                          struct mtd_oob_ops *ops);
 233         int (*write_oob) (struct mtd_info *mtd, loff_t to,
 234                          struct mtd_oob_ops *ops);
 235
 236         /*
 237          * Methods to access the protection register area, present in some
 238          * flash devices. The user data is one time programmable but the
 239          * factory data is read only.
 240          */
 241         int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 242         int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 243         int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 244         int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 245         int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 246         int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 247
 248         /* kvec-based read/write methods.
 249            NB: The 'count' parameter is the number of _vectors_, each of
 250            which contains an (ofs, len) tuple.
 251         */
 252         int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
 253
 254         /* Sync */
 255         void (*sync) (struct mtd_info *mtd);
 256
 257         /* Chip-supported device locking */
 258         int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 259         int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 260         int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 261
 262         /* Power Management functions */
 263         int (*suspend) (struct mtd_info *mtd);
 264         void (*resume) (struct mtd_info *mtd);
 265
 266         /* Bad block management functions */
 267         int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
 268         int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
 269
 270         struct notifier_block reboot_notifier;  /* default mode before reboot */
 271
 272         /* ECC status information */
 273         struct mtd_ecc_stats ecc_stats;
 274         /* Subpage shift (NAND) */
 275         int subpage_sft;
 276
 277         void *priv;
 278
 279         struct module *owner;
 280         struct device dev;
 281         int usecount;
 282
 283         /* If the driver is something smart, like UBI, it may need to maintain
 284          * its own reference counting. The below functions are only for driver.
 285          * The driver may register its callbacks. These callbacks are not
 286          * supposed to be called by MTD users */
 287         int (*get_device) (struct mtd_info *mtd);
 288         void (*put_device) (struct mtd_info *mtd);
 289 };
 290
 291 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 292 {
 293         return dev ? dev_get_drvdata(dev) : NULL;
 294 }
 295
 296 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 297 {
 298         if (mtd->erasesize_shift)
 299                 return sz >> mtd->erasesize_shift;
 300         do_div(sz, mtd->erasesize);
 301         return sz;
 302 }
 303
 304 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 305 {
 306         if (mtd->erasesize_shift)
 307                 return sz & mtd->erasesize_mask;
 308         return do_div(sz, mtd->erasesize);
 309 }
 310
 311 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 312 {
 313         if (mtd->writesize_shift)
 314                 return sz >> mtd->writesize_shift;
 315         do_div(sz, mtd->writesize);
 316         return sz;
 317 }
 318
 319 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 320 {
 321         if (mtd->writesize_shift)
 322                 return sz & mtd->writesize_mask;
 323         return do_div(sz, mtd->writesize);
 324 }
 325
 326         /* Kernel-side ioctl definitions */
 327
 328 struct mtd_partition;
 329 struct mtd_part_parser_data;
 330
 331 extern int mtd_device_parse_register(struct mtd_info *mtd,
 332                               const char **part_probe_types,
 333                               struct mtd_part_parser_data *parser_data,
 334                               const struct mtd_partition *defparts,
 335                               int defnr_parts);
 336 #define mtd_device_register(master, parts, nr_parts)    \
 337         mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
 338 extern int mtd_device_unregister(struct mtd_info *master);
 339 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 340 extern int __get_mtd_device(struct mtd_info *mtd);
 341 extern void __put_mtd_device(struct mtd_info *mtd);
 342 extern struct mtd_info *get_mtd_device_nm(const char *name);
 343 extern void put_mtd_device(struct mtd_info *mtd);
 344
 345
 346 struct mtd_notifier {
 347         void (*add)(struct mtd_info *mtd);
 348         void (*remove)(struct mtd_info *mtd);
 349         struct list_head list;
 350 };
 351
 352
 353 extern void register_mtd_user (struct mtd_notifier *new);
 354 extern int unregister_mtd_user (struct mtd_notifier *old);
 355
 356 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 357                        unsigned long count, loff_t to, size_t *retlen);
 358
 359 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
 360                       unsigned long count, loff_t from, size_t *retlen);
 361
 362 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 363
 364 void mtd_erase_callback(struct erase_info *instr);
 365
 366 #endif /* __MTD_MTD_H__ */