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 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
  44    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
  45    specific to any particular block. */
  46 struct erase_info {
  47         struct mtd_info *mtd;
  48         uint64_t addr;
  49         uint64_t len;
  50         uint64_t fail_addr;
  51         u_long time;
  52         u_long retries;
  53         unsigned dev;
  54         unsigned cell;
  55         void (*callback) (struct erase_info *self);
  56         u_long priv;
  57         u_char state;
  58         struct erase_info *next;
  59 };
  60
  61 struct mtd_erase_region_info {
  62         uint64_t offset;                        /* At which this region starts, from the beginning of the MTD */
  63         uint32_t erasesize;             /* For this region */
  64         uint32_t numblocks;             /* Number of blocks of erasesize in this region */
  65         unsigned long *lockmap;         /* If keeping bitmap of locks */
  66 };
  67
  68 /*
  69  * oob operation modes
  70  *
  71  * MTD_OOB_PLACE:       oob data are placed at the given offset
  72  * MTD_OOB_AUTO:        oob data are automatically placed at the free areas
  73  *                      which are defined by the ecclayout
  74  * MTD_OOB_RAW:         mode to read oob and data without doing ECC checking
  75  */
  76 typedef enum {
  77         MTD_OOB_PLACE,
  78         MTD_OOB_AUTO,
  79         MTD_OOB_RAW,
  80 } mtd_oob_mode_t;
  81
  82 /**
  83  * struct mtd_oob_ops - oob operation operands
  84  * @mode:       operation mode
  85  *
  86  * @len:        number of data bytes to write/read
  87  *
  88  * @retlen:     number of data bytes written/read
  89  *
  90  * @ooblen:     number of oob bytes to write/read
  91  * @oobretlen:  number of oob bytes written/read
  92  * @ooboffs:    offset of oob data in the oob area (only relevant when
  93  *              mode = MTD_OOB_PLACE)
  94  * @datbuf:     data buffer - if NULL only oob data are read/written
  95  * @oobbuf:     oob data buffer
  96  *
  97  * Note, it is allowed to read more than one OOB area at one go, but not write.
  98  * The interface assumes that the OOB write requests program only one page's
  99  * OOB area.
 100  */
 101 struct mtd_oob_ops {
 102         mtd_oob_mode_t  mode;
 103         size_t          len;
 104         size_t          retlen;
 105         size_t          ooblen;
 106         size_t          oobretlen;
 107         uint32_t        ooboffs;
 108         uint8_t         *datbuf;
 109         uint8_t         *oobbuf;
 110 };
 111
 112 #define MTD_MAX_OOBFREE_ENTRIES_LARGE   32
 113 #define MTD_MAX_ECCPOS_ENTRIES_LARGE    448
 114 /*
 115  * Internal ECC layout control structure. For historical reasons, there is a
 116  * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
 117  * for export to user-space via the ECCGETLAYOUT ioctl.
 118  * nand_ecclayout should be expandable in the future simply by the above macros.
 119  */
 120 struct nand_ecclayout {
 121         __u32 eccbytes;
 122         __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
 123         __u32 oobavail;
 124         struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
 125 };
 126
 127 struct module;  /* only needed for owner field in mtd_info */
 128
 129 struct mtd_info {
 130         u_char type;
 131         uint32_t flags;
 132         uint64_t size;   // Total size of the MTD
 133
 134         /* "Major" erase size for the device. Naïve users may take this
 135          * to be the only erase size available, or may use the more detailed
 136          * information below if they desire
 137          */
 138         uint32_t erasesize;
 139         /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
 140          * though individual bits can be cleared), in case of NAND flash it is
 141          * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
 142          * it is of ECC block size, etc. It is illegal to have writesize = 0.
 143          * Any driver registering a struct mtd_info must ensure a writesize of
 144          * 1 or larger.
 145          */
 146         uint32_t writesize;
 147
 148         /*
 149          * Size of the write buffer used by the MTD. MTD devices having a write
 150          * buffer can write multiple writesize chunks at a time. E.g. while
 151          * writing 4 * writesize bytes to a device with 2 * writesize bytes
 152          * buffer the MTD driver can (but doesn't have to) do 2 writesize
 153          * operations, but not 4. Currently, all NANDs have writebufsize
 154          * equivalent to writesize (NAND page size). Some NOR flashes do have
 155          * writebufsize greater than writesize.
 156          */
 157         uint32_t writebufsize;
 158
 159         uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 160         uint32_t oobavail;  // Available OOB bytes per block
 161
 162         /*
 163          * If erasesize is a power of 2 then the shift is stored in
 164          * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
 165          */
 166         unsigned int erasesize_shift;
 167         unsigned int writesize_shift;
 168         /* Masks based on erasesize_shift and writesize_shift */
 169         unsigned int erasesize_mask;
 170         unsigned int writesize_mask;
 171
 172         // Kernel-only stuff starts here.
 173         const char *name;
 174         int index;
 175
 176         /* ecc layout structure pointer - read only ! */
 177         struct nand_ecclayout *ecclayout;
 178
 179         /* Data for variable erase regions. If numeraseregions is zero,
 180          * it means that the whole device has erasesize as given above.
 181          */
 182         int numeraseregions;
 183         struct mtd_erase_region_info *eraseregions;
 184
 185         /*
 186          * Erase is an asynchronous operation.  Device drivers are supposed
 187          * to call instr->callback() whenever the operation completes, even
 188          * if it completes with a failure.
 189          * Callers are supposed to pass a callback function and wait for it
 190          * to be called before writing to the block.
 191          */
 192         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 193
 194         /* This stuff for eXecute-In-Place */
 195         /* phys is optional and may be set to NULL */
 196         int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
 197                         size_t *retlen, void **virt, resource_size_t *phys);
 198
 199         /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 200         void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 201
 202         /* Allow NOMMU mmap() to directly map the device (if not NULL)
 203          * - return the address to which the offset maps
 204          * - return -ENOSYS to indicate refusal to do the mapping
 205          */
 206         unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
 207                                             unsigned long len,
 208                                             unsigned long offset,
 209                                             unsigned long flags);
 210
 211         /* Backing device capabilities for this device
 212          * - provides mmap capabilities
 213          */
 214         struct backing_dev_info *backing_dev_info;
 215
 216
 217         int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 218         int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 219
 220         /* In blackbox flight recorder like scenarios we want to make successful
 221            writes in interrupt context. panic_write() is only intended to be
 222            called when its known the kernel is about to panic and we need the
 223            write to succeed. Since the kernel is not going to be running for much
 224            longer, this function can break locks and delay to ensure the write
 225            succeeds (but not sleep). */
 226
 227         int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 228
 229         int (*read_oob) (struct mtd_info *mtd, loff_t from,
 230                          struct mtd_oob_ops *ops);
 231         int (*write_oob) (struct mtd_info *mtd, loff_t to,
 232                          struct mtd_oob_ops *ops);
 233
 234         /*
 235          * Methods to access the protection register area, present in some
 236          * flash devices. The user data is one time programmable but the
 237          * factory data is read only.
 238          */
 239         int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 240         int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 241         int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 242         int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 243         int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 244         int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 245
 246         /* kvec-based read/write methods.
 247            NB: The 'count' parameter is the number of _vectors_, each of
 248            which contains an (ofs, len) tuple.
 249         */
 250         int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
 251
 252         /* Sync */
 253         void (*sync) (struct mtd_info *mtd);
 254
 255         /* Chip-supported device locking */
 256         int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 257         int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 258         int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 259
 260         /* Power Management functions */
 261         int (*suspend) (struct mtd_info *mtd);
 262         void (*resume) (struct mtd_info *mtd);
 263
 264         /* Bad block management functions */
 265         int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
 266         int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
 267
 268         struct notifier_block reboot_notifier;  /* default mode before reboot */
 269
 270         /* ECC status information */
 271         struct mtd_ecc_stats ecc_stats;
 272         /* Subpage shift (NAND) */
 273         int subpage_sft;
 274
 275         void *priv;
 276
 277         struct module *owner;
 278         struct device dev;
 279         int usecount;
 280
 281         /* If the driver is something smart, like UBI, it may need to maintain
 282          * its own reference counting. The below functions are only for driver.
 283          * The driver may register its callbacks. These callbacks are not
 284          * supposed to be called by MTD users */
 285         int (*get_device) (struct mtd_info *mtd);
 286         void (*put_device) (struct mtd_info *mtd);
 287 };
 288
 289 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 290 {
 291         return dev ? dev_get_drvdata(dev) : NULL;
 292 }
 293
 294 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 295 {
 296         if (mtd->erasesize_shift)
 297                 return sz >> mtd->erasesize_shift;
 298         do_div(sz, mtd->erasesize);
 299         return sz;
 300 }
 301
 302 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 303 {
 304         if (mtd->erasesize_shift)
 305                 return sz & mtd->erasesize_mask;
 306         return do_div(sz, mtd->erasesize);
 307 }
 308
 309 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 310 {
 311         if (mtd->writesize_shift)
 312                 return sz >> mtd->writesize_shift;
 313         do_div(sz, mtd->writesize);
 314         return sz;
 315 }
 316
 317 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 318 {
 319         if (mtd->writesize_shift)
 320                 return sz & mtd->writesize_mask;
 321         return do_div(sz, mtd->writesize);
 322 }
 323
 324         /* Kernel-side ioctl definitions */
 325
 326 struct mtd_partition;
 327
 328 extern int mtd_device_register(struct mtd_info *master,
 329                                const struct mtd_partition *parts,
 330                                int nr_parts);
 331 extern int mtd_device_unregister(struct mtd_info *master);
 332 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 333 extern int __get_mtd_device(struct mtd_info *mtd);
 334 extern void __put_mtd_device(struct mtd_info *mtd);
 335 extern struct mtd_info *get_mtd_device_nm(const char *name);
 336 extern void put_mtd_device(struct mtd_info *mtd);
 337
 338
 339 struct mtd_notifier {
 340         void (*add)(struct mtd_info *mtd);
 341         void (*remove)(struct mtd_info *mtd);
 342         struct list_head list;
 343 };
 344
 345
 346 extern void register_mtd_user (struct mtd_notifier *new);
 347 extern int unregister_mtd_user (struct mtd_notifier *old);
 348
 349 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 350                        unsigned long count, loff_t to, size_t *retlen);
 351
 352 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
 353                       unsigned long count, loff_t from, size_t *retlen);
 354
 355 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
 356
 357 void mtd_erase_callback(struct erase_info *instr);
 358
 359 /*
 360  * Debugging macro and defines
 361  */
 362 #define MTD_DEBUG_LEVEL0        (0)     /* Quiet   */
 363 #define MTD_DEBUG_LEVEL1        (1)     /* Audible */
 364 #define MTD_DEBUG_LEVEL2        (2)     /* Loud    */
 365 #define MTD_DEBUG_LEVEL3        (3)     /* Noisy   */
 366
 367 #ifdef CONFIG_MTD_DEBUG
 368 #define DEBUG(n, args...)                               \
 369         do {                                            \
 370                 if (n <= CONFIG_MTD_DEBUG_VERBOSE)      \
 371                         printk(KERN_INFO args);         \
 372         } while(0)
 373 #else /* CONFIG_MTD_DEBUG */
 374 #define DEBUG(n, args...)                               \
 375         do {                                            \
 376                 if (0)                                  \
 377                         printk(KERN_INFO args);         \
 378         } while(0)
 379
 380 #endif /* CONFIG_MTD_DEBUG */
 381
 382 #endif /* __MTD_MTD_H__ */