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