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  * struct mtd_oob_ops - oob operation operands
  72  * @mode:       operation mode
  73  *
  74  * @len:        number of data bytes to write/read
  75  *
  76  * @retlen:     number of data bytes written/read
  77  *
  78  * @ooblen:     number of oob bytes to write/read
  79  * @oobretlen:  number of oob bytes written/read
  80  * @ooboffs:    offset of oob data in the oob area (only relevant when
  81  *              mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
  82  * @datbuf:     data buffer - if NULL only oob data are read/written
  83  * @oobbuf:     oob data buffer
  84  *
  85  * Note, it is allowed to read more than one OOB area at one go, but not write.
  86  * The interface assumes that the OOB write requests program only one page's
  87  * OOB area.
  88  */
  89 struct mtd_oob_ops {
  90         unsigned int    mode;
  91         size_t          len;
  92         size_t          retlen;
  93         size_t          ooblen;
  94         size_t          oobretlen;
  95         uint32_t        ooboffs;
  96         uint8_t         *datbuf;
  97         uint8_t         *oobbuf;
  98 };
  99
 100 #define MTD_MAX_OOBFREE_ENTRIES_LARGE   32
 101 #define MTD_MAX_ECCPOS_ENTRIES_LARGE    448
 102 /*
 103  * Internal ECC layout control structure. For historical reasons, there is a
 104  * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
 105  * for export to user-space via the ECCGETLAYOUT ioctl.
 106  * nand_ecclayout should be expandable in the future simply by the above macros.
 107  */
 108 struct nand_ecclayout {
 109         __u32 eccbytes;
 110         __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
 111         __u32 oobavail;
 112         struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
 113 };
 114
 115 struct module;  /* only needed for owner field in mtd_info */
 116
 117 struct mtd_info {
 118         u_char type;
 119         uint32_t flags;
 120         uint64_t size;   // Total size of the MTD
 121
 122         /* "Major" erase size for the device. Naïve users may take this
 123          * to be the only erase size available, or may use the more detailed
 124          * information below if they desire
 125          */
 126         uint32_t erasesize;
 127         /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
 128          * though individual bits can be cleared), in case of NAND flash it is
 129          * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
 130          * it is of ECC block size, etc. It is illegal to have writesize = 0.
 131          * Any driver registering a struct mtd_info must ensure a writesize of
 132          * 1 or larger.
 133          */
 134         uint32_t writesize;
 135
 136         /*
 137          * Size of the write buffer used by the MTD. MTD devices having a write
 138          * buffer can write multiple writesize chunks at a time. E.g. while
 139          * writing 4 * writesize bytes to a device with 2 * writesize bytes
 140          * buffer the MTD driver can (but doesn't have to) do 2 writesize
 141          * operations, but not 4. Currently, all NANDs have writebufsize
 142          * equivalent to writesize (NAND page size). Some NOR flashes do have
 143          * writebufsize greater than writesize.
 144          */
 145         uint32_t writebufsize;
 146
 147         uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 148         uint32_t oobavail;  // Available OOB bytes per block
 149
 150         /*
 151          * If erasesize is a power of 2 then the shift is stored in
 152          * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
 153          */
 154         unsigned int erasesize_shift;
 155         unsigned int writesize_shift;
 156         /* Masks based on erasesize_shift and writesize_shift */
 157         unsigned int erasesize_mask;
 158         unsigned int writesize_mask;
 159
 160         // Kernel-only stuff starts here.
 161         const char *name;
 162         int index;
 163
 164         /* ECC layout structure pointer - read only! */
 165         struct nand_ecclayout *ecclayout;
 166
 167         /* Data for variable erase regions. If numeraseregions is zero,
 168          * it means that the whole device has erasesize as given above.
 169          */
 170         int numeraseregions;
 171         struct mtd_erase_region_info *eraseregions;
 172
 173         /*
 174          * Do not call via these pointers, use corresponding mtd_*()
 175          * wrappers instead.
 176          */
 177         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 178
 179         /* This stuff for eXecute-In-Place */
 180         /* phys is optional and may be set to NULL */
 181         int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
 182                         size_t *retlen, void **virt, resource_size_t *phys);
 183
 184         /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 185         void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 186
 187         /* Allow NOMMU mmap() to directly map the device (if not NULL)
 188          * - return the address to which the offset maps
 189          * - return -ENOSYS to indicate refusal to do the mapping
 190          */
 191         unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
 192                                             unsigned long len,
 193                                             unsigned long offset,
 194                                             unsigned long flags);
 195
 196         /* Backing device capabilities for this device
 197          * - provides mmap capabilities
 198          */
 199         struct backing_dev_info *backing_dev_info;
 200
 201
 202         int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 203         int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 204
 205         /* In blackbox flight recorder like scenarios we want to make successful
 206            writes in interrupt context. panic_write() is only intended to be
 207            called when its known the kernel is about to panic and we need the
 208            write to succeed. Since the kernel is not going to be running for much
 209            longer, this function can break locks and delay to ensure the write
 210            succeeds (but not sleep). */
 211
 212         int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 213
 214         int (*read_oob) (struct mtd_info *mtd, loff_t from,
 215                          struct mtd_oob_ops *ops);
 216         int (*write_oob) (struct mtd_info *mtd, loff_t to,
 217                          struct mtd_oob_ops *ops);
 218
 219         /*
 220          * Methods to access the protection register area, present in some
 221          * flash devices. The user data is one time programmable but the
 222          * factory data is read only.
 223          */
 224         int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 225         int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 226         int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 227         int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 228         int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 229         int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 230
 231         /* kvec-based read/write methods.
 232            NB: The 'count' parameter is the number of _vectors_, each of
 233            which contains an (ofs, len) tuple.
 234         */
 235         int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
 236
 237         /* Sync */
 238         void (*sync) (struct mtd_info *mtd);
 239
 240         /* Chip-supported device locking */
 241         int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 242         int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 243         int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 244
 245         /* Power Management functions */
 246         int (*suspend) (struct mtd_info *mtd);
 247         void (*resume) (struct mtd_info *mtd);
 248
 249         /* Bad block management functions */
 250         int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
 251         int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
 252
 253         struct notifier_block reboot_notifier;  /* default mode before reboot */
 254
 255         /* ECC status information */
 256         struct mtd_ecc_stats ecc_stats;
 257         /* Subpage shift (NAND) */
 258         int subpage_sft;
 259
 260         void *priv;
 261
 262         struct module *owner;
 263         struct device dev;
 264         int usecount;
 265
 266         /* If the driver is something smart, like UBI, it may need to maintain
 267          * its own reference counting. The below functions are only for driver.
 268          * The driver may register its callbacks. These callbacks are not
 269          * supposed to be called by MTD users */
 270         int (*get_device) (struct mtd_info *mtd);
 271         void (*put_device) (struct mtd_info *mtd);
 272 };
 273
 274 /*
 275  * Erase is an asynchronous operation.  Device drivers are supposed
 276  * to call instr->callback() whenever the operation completes, even
 277  * if it completes with a failure.
 278  * Callers are supposed to pass a callback function and wait for it
 279  * to be called before writing to the block.
 280  */
 281 static inline int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 282 {
 283         return mtd->erase(mtd, instr);
 284 }
 285
 286 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 287 {
 288         return dev ? dev_get_drvdata(dev) : NULL;
 289 }
 290
 291 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 292 {
 293         if (mtd->erasesize_shift)
 294                 return sz >> mtd->erasesize_shift;
 295         do_div(sz, mtd->erasesize);
 296         return sz;
 297 }
 298
 299 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 300 {
 301         if (mtd->erasesize_shift)
 302                 return sz & mtd->erasesize_mask;
 303         return do_div(sz, mtd->erasesize);
 304 }
 305
 306 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 307 {
 308         if (mtd->writesize_shift)
 309                 return sz >> mtd->writesize_shift;
 310         do_div(sz, mtd->writesize);
 311         return sz;
 312 }
 313
 314 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 315 {
 316         if (mtd->writesize_shift)
 317                 return sz & mtd->writesize_mask;
 318         return do_div(sz, mtd->writesize);
 319 }
 320
 321         /* Kernel-side ioctl definitions */
 322
 323 struct mtd_partition;
 324 struct mtd_part_parser_data;
 325
 326 extern int mtd_device_parse_register(struct mtd_info *mtd,
 327                               const char **part_probe_types,
 328                               struct mtd_part_parser_data *parser_data,
 329                               const struct mtd_partition *defparts,
 330                               int defnr_parts);
 331 #define mtd_device_register(master, parts, nr_parts)    \
 332         mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
 333 extern int mtd_device_unregister(struct mtd_info *master);
 334 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 335 extern int __get_mtd_device(struct mtd_info *mtd);
 336 extern void __put_mtd_device(struct mtd_info *mtd);
 337 extern struct mtd_info *get_mtd_device_nm(const char *name);
 338 extern void put_mtd_device(struct mtd_info *mtd);
 339
 340
 341 struct mtd_notifier {
 342         void (*add)(struct mtd_info *mtd);
 343         void (*remove)(struct mtd_info *mtd);
 344         struct list_head list;
 345 };
 346
 347
 348 extern void register_mtd_user (struct mtd_notifier *new);
 349 extern int unregister_mtd_user (struct mtd_notifier *old);
 350
 351 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 352                        unsigned long count, loff_t to, size_t *retlen);
 353
 354 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
 355                       unsigned long count, loff_t from, size_t *retlen);
 356
 357 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 358
 359 void mtd_erase_callback(struct erase_info *instr);
 360
 361 static inline int mtd_is_bitflip(int err) {
 362         return err == -EUCLEAN;
 363 }
 364
 365 static inline int mtd_is_eccerr(int err) {
 366         return err == -EBADMSG;
 367 }
 368
 369 static inline int mtd_is_bitflip_or_eccerr(int err) {
 370         return mtd_is_bitflip(err) || mtd_is_eccerr(err);
 371 }
 372
 373 #endif /* __MTD_MTD_H__ */