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