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         int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
 179                       size_t *retlen, void **virt, resource_size_t *phys);
 180
 181         /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 182         void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 183
 184         /* Allow NOMMU mmap() to directly map the device (if not NULL)
 185          * - return the address to which the offset maps
 186          * - return -ENOSYS to indicate refusal to do the mapping
 187          */
 188         unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
 189                                             unsigned long len,
 190                                             unsigned long offset,
 191                                             unsigned long flags);
 192
 193         /* Backing device capabilities for this device
 194          * - provides mmap capabilities
 195          */
 196         struct backing_dev_info *backing_dev_info;
 197
 198
 199         int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 200         int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 201
 202         /* In blackbox flight recorder like scenarios we want to make successful
 203            writes in interrupt context. panic_write() is only intended to be
 204            called when its known the kernel is about to panic and we need the
 205            write to succeed. Since the kernel is not going to be running for much
 206            longer, this function can break locks and delay to ensure the write
 207            succeeds (but not sleep). */
 208
 209         int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 210
 211         int (*read_oob) (struct mtd_info *mtd, loff_t from,
 212                          struct mtd_oob_ops *ops);
 213         int (*write_oob) (struct mtd_info *mtd, loff_t to,
 214                          struct mtd_oob_ops *ops);
 215
 216         /*
 217          * Methods to access the protection register area, present in some
 218          * flash devices. The user data is one time programmable but the
 219          * factory data is read only.
 220          */
 221         int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 222         int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 223         int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 224         int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 225         int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 226         int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 227
 228         /* kvec-based read/write methods.
 229            NB: The 'count' parameter is the number of _vectors_, each of
 230            which contains an (ofs, len) tuple.
 231         */
 232         int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
 233
 234         /* Sync */
 235         void (*sync) (struct mtd_info *mtd);
 236
 237         /* Chip-supported device locking */
 238         int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 239         int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 240         int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 241
 242         /* Power Management functions */
 243         int (*suspend) (struct mtd_info *mtd);
 244         void (*resume) (struct mtd_info *mtd);
 245
 246         /* Bad block management functions */
 247         int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
 248         int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
 249
 250         struct notifier_block reboot_notifier;  /* default mode before reboot */
 251
 252         /* ECC status information */
 253         struct mtd_ecc_stats ecc_stats;
 254         /* Subpage shift (NAND) */
 255         int subpage_sft;
 256
 257         void *priv;
 258
 259         struct module *owner;
 260         struct device dev;
 261         int usecount;
 262
 263         /* If the driver is something smart, like UBI, it may need to maintain
 264          * its own reference counting. The below functions are only for driver.
 265          * The driver may register its callbacks. These callbacks are not
 266          * supposed to be called by MTD users */
 267         int (*get_device) (struct mtd_info *mtd);
 268         void (*put_device) (struct mtd_info *mtd);
 269 };
 270
 271 /*
 272  * Erase is an asynchronous operation.  Device drivers are supposed
 273  * to call instr->callback() whenever the operation completes, even
 274  * if it completes with a failure.
 275  * Callers are supposed to pass a callback function and wait for it
 276  * to be called before writing to the block.
 277  */
 278 static inline int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 279 {
 280         return mtd->erase(mtd, instr);
 281 }
 282
 283 /*
 284  * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
 285  */
 286 static inline int mtd_point(struct mtd_info *mtd, loff_t from, size_t len,
 287                             size_t *retlen, void **virt, resource_size_t *phys)
 288 {
 289         return mtd->point(mtd, from, len, retlen, virt, phys);
 290 }
 291
 292 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 293 {
 294         return dev ? dev_get_drvdata(dev) : NULL;
 295 }
 296
 297 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 298 {
 299         if (mtd->erasesize_shift)
 300                 return sz >> mtd->erasesize_shift;
 301         do_div(sz, mtd->erasesize);
 302         return sz;
 303 }
 304
 305 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 306 {
 307         if (mtd->erasesize_shift)
 308                 return sz & mtd->erasesize_mask;
 309         return do_div(sz, mtd->erasesize);
 310 }
 311
 312 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 313 {
 314         if (mtd->writesize_shift)
 315                 return sz >> mtd->writesize_shift;
 316         do_div(sz, mtd->writesize);
 317         return sz;
 318 }
 319
 320 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 321 {
 322         if (mtd->writesize_shift)
 323                 return sz & mtd->writesize_mask;
 324         return do_div(sz, mtd->writesize);
 325 }
 326
 327         /* Kernel-side ioctl definitions */
 328
 329 struct mtd_partition;
 330 struct mtd_part_parser_data;
 331
 332 extern int mtd_device_parse_register(struct mtd_info *mtd,
 333                               const char **part_probe_types,
 334                               struct mtd_part_parser_data *parser_data,
 335                               const struct mtd_partition *defparts,
 336                               int defnr_parts);
 337 #define mtd_device_register(master, parts, nr_parts)    \
 338         mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
 339 extern int mtd_device_unregister(struct mtd_info *master);
 340 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 341 extern int __get_mtd_device(struct mtd_info *mtd);
 342 extern void __put_mtd_device(struct mtd_info *mtd);
 343 extern struct mtd_info *get_mtd_device_nm(const char *name);
 344 extern void put_mtd_device(struct mtd_info *mtd);
 345
 346
 347 struct mtd_notifier {
 348         void (*add)(struct mtd_info *mtd);
 349         void (*remove)(struct mtd_info *mtd);
 350         struct list_head list;
 351 };
 352
 353
 354 extern void register_mtd_user (struct mtd_notifier *new);
 355 extern int unregister_mtd_user (struct mtd_notifier *old);
 356
 357 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 358                        unsigned long count, loff_t to, size_t *retlen);
 359
 360 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
 361                       unsigned long count, loff_t from, size_t *retlen);
 362
 363 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 364
 365 void mtd_erase_callback(struct erase_info *instr);
 366
 367 static inline int mtd_is_bitflip(int err) {
 368         return err == -EUCLEAN;
 369 }
 370
 371 static inline int mtd_is_eccerr(int err) {
 372         return err == -EBADMSG;
 373 }
 374
 375 static inline int mtd_is_bitflip_or_eccerr(int err) {
 376         return mtd_is_bitflip(err) || mtd_is_eccerr(err);
 377 }
 378
 379 #endif /* __MTD_MTD_H__ */