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 <linux/mtd/compatmac.h>
  30 #include <mtd/mtd-abi.h>
  31
  32 #include <asm/div64.h>
  33
  34 #define MTD_CHAR_MAJOR 90
  35 #define MTD_BLOCK_MAJOR 31
  36
  37 #define MTD_ERASE_PENDING       0x01
  38 #define MTD_ERASING             0x02
  39 #define MTD_ERASE_SUSPEND       0x04
  40 #define MTD_ERASE_DONE          0x08
  41 #define MTD_ERASE_FAILED        0x10
  42
  43 #define MTD_FAIL_ADDR_UNKNOWN -1LL
  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 or was not
  47    specific to any particular block. */
  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  * oob operation modes
  72  *
  73  * MTD_OOB_PLACE:       oob data are placed at the given offset
  74  * MTD_OOB_AUTO:        oob data are automatically placed at the free areas
  75  *                      which are defined by the ecclayout
  76  * MTD_OOB_RAW:         mode to read oob and data without doing ECC checking
  77  */
  78 typedef enum {
  79         MTD_OOB_PLACE,
  80         MTD_OOB_AUTO,
  81         MTD_OOB_RAW,
  82 } mtd_oob_mode_t;
  83
  84 /**
  85  * struct mtd_oob_ops - oob operation operands
  86  * @mode:       operation mode
  87  *
  88  * @len:        number of data bytes to write/read
  89  *
  90  * @retlen:     number of data bytes written/read
  91  *
  92  * @ooblen:     number of oob bytes to write/read
  93  * @oobretlen:  number of oob bytes written/read
  94  * @ooboffs:    offset of oob data in the oob area (only relevant when
  95  *              mode = MTD_OOB_PLACE)
  96  * @datbuf:     data buffer - if NULL only oob data are read/written
  97  * @oobbuf:     oob data buffer
  98  *
  99  * Note, it is allowed to read more than one OOB area at one go, but not write.
 100  * The interface assumes that the OOB write requests program only one page's
 101  * OOB area.
 102  */
 103 struct mtd_oob_ops {
 104         mtd_oob_mode_t  mode;
 105         size_t          len;
 106         size_t          retlen;
 107         size_t          ooblen;
 108         size_t          oobretlen;
 109         uint32_t        ooboffs;
 110         uint8_t         *datbuf;
 111         uint8_t         *oobbuf;
 112 };
 113
 114 struct mtd_info {
 115         u_char type;
 116         uint32_t flags;
 117         uint64_t size;   // Total size of the MTD
 118
 119         /* "Major" erase size for the device. Naïve users may take this
 120          * to be the only erase size available, or may use the more detailed
 121          * information below if they desire
 122          */
 123         uint32_t erasesize;
 124         /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
 125          * though individual bits can be cleared), in case of NAND flash it is
 126          * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
 127          * it is of ECC block size, etc. It is illegal to have writesize = 0.
 128          * Any driver registering a struct mtd_info must ensure a writesize of
 129          * 1 or larger.
 130          */
 131         uint32_t writesize;
 132
 133         uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 134         uint32_t oobavail;  // Available OOB bytes per block
 135
 136         /*
 137          * If erasesize is a power of 2 then the shift is stored in
 138          * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
 139          */
 140         unsigned int erasesize_shift;
 141         unsigned int writesize_shift;
 142         /* Masks based on erasesize_shift and writesize_shift */
 143         unsigned int erasesize_mask;
 144         unsigned int writesize_mask;
 145
 146         // Kernel-only stuff starts here.
 147         const char *name;
 148         int index;
 149
 150         /* ecc layout structure pointer - read only ! */
 151         struct nand_ecclayout *ecclayout;
 152
 153         /* Data for variable erase regions. If numeraseregions is zero,
 154          * it means that the whole device has erasesize as given above.
 155          */
 156         int numeraseregions;
 157         struct mtd_erase_region_info *eraseregions;
 158
 159         /*
 160          * Erase is an asynchronous operation.  Device drivers are supposed
 161          * to call instr->callback() whenever the operation completes, even
 162          * if it completes with a failure.
 163          * Callers are supposed to pass a callback function and wait for it
 164          * to be called before writing to the block.
 165          */
 166         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 167
 168         /* This stuff for eXecute-In-Place */
 169         /* phys is optional and may be set to NULL */
 170         int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
 171                         size_t *retlen, void **virt, resource_size_t *phys);
 172
 173         /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 174         void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 175
 176         /* Allow NOMMU mmap() to directly map the device (if not NULL)
 177          * - return the address to which the offset maps
 178          * - return -ENOSYS to indicate refusal to do the mapping
 179          */
 180         unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
 181                                             unsigned long len,
 182                                             unsigned long offset,
 183                                             unsigned long flags);
 184
 185         /* Backing device capabilities for this device
 186          * - provides mmap capabilities
 187          */
 188         struct backing_dev_info *backing_dev_info;
 189
 190
 191         int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 192         int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 193
 194         /* In blackbox flight recorder like scenarios we want to make successful
 195            writes in interrupt context. panic_write() is only intended to be
 196            called when its known the kernel is about to panic and we need the
 197            write to succeed. Since the kernel is not going to be running for much
 198            longer, this function can break locks and delay to ensure the write
 199            succeeds (but not sleep). */
 200
 201         int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
 202
 203         int (*read_oob) (struct mtd_info *mtd, loff_t from,
 204                          struct mtd_oob_ops *ops);
 205         int (*write_oob) (struct mtd_info *mtd, loff_t to,
 206                          struct mtd_oob_ops *ops);
 207
 208         /*
 209          * Methods to access the protection register area, present in some
 210          * flash devices. The user data is one time programmable but the
 211          * factory data is read only.
 212          */
 213         int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 214         int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 215         int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
 216         int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 217         int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
 218         int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
 219
 220         /* kvec-based read/write methods.
 221            NB: The 'count' parameter is the number of _vectors_, each of
 222            which contains an (ofs, len) tuple.
 223         */
 224         int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
 225
 226         /* Sync */
 227         void (*sync) (struct mtd_info *mtd);
 228
 229         /* Chip-supported device locking */
 230         int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 231         int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 232         int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 233
 234         /* Power Management functions */
 235         int (*suspend) (struct mtd_info *mtd);
 236         void (*resume) (struct mtd_info *mtd);
 237
 238         /* Bad block management functions */
 239         int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
 240         int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
 241
 242         struct notifier_block reboot_notifier;  /* default mode before reboot */
 243
 244         /* ECC status information */
 245         struct mtd_ecc_stats ecc_stats;
 246         /* Subpage shift (NAND) */
 247         int subpage_sft;
 248
 249         void *priv;
 250
 251         struct module *owner;
 252         struct device dev;
 253         int usecount;
 254
 255         /* If the driver is something smart, like UBI, it may need to maintain
 256          * its own reference counting. The below functions are only for driver.
 257          * The driver may register its callbacks. These callbacks are not
 258          * supposed to be called by MTD users */
 259         int (*get_device) (struct mtd_info *mtd);
 260         void (*put_device) (struct mtd_info *mtd);
 261 };
 262
 263 static inline struct mtd_info *dev_to_mtd(struct device *dev)
 264 {
 265         return dev ? dev_get_drvdata(dev) : NULL;
 266 }
 267
 268 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 269 {
 270         if (mtd->erasesize_shift)
 271                 return sz >> mtd->erasesize_shift;
 272         do_div(sz, mtd->erasesize);
 273         return sz;
 274 }
 275
 276 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 277 {
 278         if (mtd->erasesize_shift)
 279                 return sz & mtd->erasesize_mask;
 280         return do_div(sz, mtd->erasesize);
 281 }
 282
 283 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 284 {
 285         if (mtd->writesize_shift)
 286                 return sz >> mtd->writesize_shift;
 287         do_div(sz, mtd->writesize);
 288         return sz;
 289 }
 290
 291 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 292 {
 293         if (mtd->writesize_shift)
 294                 return sz & mtd->writesize_mask;
 295         return do_div(sz, mtd->writesize);
 296 }
 297
 298         /* Kernel-side ioctl definitions */
 299
 300 extern int add_mtd_device(struct mtd_info *mtd);
 301 extern int del_mtd_device (struct mtd_info *mtd);
 302
 303 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 304 extern int __get_mtd_device(struct mtd_info *mtd);
 305 extern void __put_mtd_device(struct mtd_info *mtd);
 306 extern struct mtd_info *get_mtd_device_nm(const char *name);
 307 extern void put_mtd_device(struct mtd_info *mtd);
 308
 309
 310 struct mtd_notifier {
 311         void (*add)(struct mtd_info *mtd);
 312         void (*remove)(struct mtd_info *mtd);
 313         struct list_head list;
 314 };
 315
 316
 317 extern void register_mtd_user (struct mtd_notifier *new);
 318 extern int unregister_mtd_user (struct mtd_notifier *old);
 319
 320 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 321                        unsigned long count, loff_t to, size_t *retlen);
 322
 323 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
 324                       unsigned long count, loff_t from, size_t *retlen);
 325
 326 #ifdef CONFIG_MTD_PARTITIONS
 327 void mtd_erase_callback(struct erase_info *instr);
 328 #else
 329 static inline void mtd_erase_callback(struct erase_info *instr)
 330 {
 331         if (instr->callback)
 332                 instr->callback(instr);
 333 }
 334 #endif
 335
 336 /*
 337  * Debugging macro and defines
 338  */
 339 #define MTD_DEBUG_LEVEL0        (0)     /* Quiet   */
 340 #define MTD_DEBUG_LEVEL1        (1)     /* Audible */
 341 #define MTD_DEBUG_LEVEL2        (2)     /* Loud    */
 342 #define MTD_DEBUG_LEVEL3        (3)     /* Noisy   */
 343
 344 #ifdef CONFIG_MTD_DEBUG
 345 #define DEBUG(n, args...)                               \
 346         do {                                            \
 347                 if (n <= CONFIG_MTD_DEBUG_VERBOSE)      \
 348                         printk(KERN_INFO args);         \
 349         } while(0)
 350 #else /* CONFIG_MTD_DEBUG */
 351 #define DEBUG(n, args...)                               \
 352         do {                                            \
 353                 if (0)                                  \
 354                         printk(KERN_INFO args);         \
 355         } while(0)
 356
 357 #endif /* CONFIG_MTD_DEBUG */
 358
 359 #endif /* __MTD_MTD_H__ */