include/linux/mtd/partitions.h

   1 /*
   2  * MTD partitioning layer definitions
   3  *
   4  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
   5  *
   6  * This code is GPL
   7  */
   8
   9 #ifndef MTD_PARTITIONS_H
  10 #define MTD_PARTITIONS_H
  11
  12 #include <linux/types.h>
  13
  14
  15 /*
  16  * Partition definition structure:
  17  *
  18  * An array of struct partition is passed along with a MTD object to
  19  * mtd_device_register() to create them.
  20  *
  21  * For each partition, these fields are available:
  22  * name: string that will be used to label the partition's MTD device.
  23  * size: the partition size; if defined as MTDPART_SIZ_FULL, the partition
  24  *      will extend to the end of the master MTD device.
  25  * offset: absolute starting position within the master MTD device; if
  26  *      defined as MTDPART_OFS_APPEND, the partition will start where the
  27  *      previous one ended; if MTDPART_OFS_NXTBLK, at the next erase block;
  28  *      if MTDPART_OFS_RETAIN, consume as much as possible, leaving size
  29  *      after the end of partition.
  30  * mask_flags: contains flags that have to be masked (removed) from the
  31  *      master MTD flag set for the corresponding MTD partition.
  32  *      For example, to force a read-only partition, simply adding
  33  *      MTD_WRITEABLE to the mask_flags will do the trick.
  34  *
  35  * Note: writeable partitions require their size and offset be
  36  * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
  37  */
  38
  39 struct mtd_partition {
  40         const char *name;               /* identifier string */
  41         uint64_t size;                  /* partition size */
  42         uint64_t offset;                /* offset within the master MTD space */
  43         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
  44 };
  45
  46 #define MTDPART_OFS_RETAIN      (-3)
  47 #define MTDPART_OFS_NXTBLK      (-2)
  48 #define MTDPART_OFS_APPEND      (-1)
  49 #define MTDPART_SIZ_FULL        (0)
  50
  51
  52 struct mtd_info;
  53 struct device_node;
  54
  55 /**
  56  * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
  57  * @origin: for RedBoot, start address of MTD device
  58  */
  59 struct mtd_part_parser_data {
  60         unsigned long origin;
  61 };
  62
  63
  64 /*
  65  * Functions dealing with the various ways of partitioning the space
  66  */
  67
  68 struct mtd_part_parser {
  69         struct list_head list;
  70         struct module *owner;
  71         const char *name;
  72         int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
  73                         struct mtd_part_parser_data *);
  74         void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
  75 };
  76
  77 /* Container for passing around a set of parsed partitions */
  78 struct mtd_partitions {
  79         const struct mtd_partition *parts;
  80         int nr_parts;
  81         const struct mtd_part_parser *parser;
  82 };
  83
  84 extern int __register_mtd_parser(struct mtd_part_parser *parser,
  85                                  struct module *owner);
  86 #define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
  87
  88 extern void deregister_mtd_parser(struct mtd_part_parser *parser);
  89
  90 /*
  91  * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
  92  * do anything special in module init/exit. Each driver may only use this macro
  93  * once, and calling it replaces module_init() and module_exit().
  94  */
  95 #define module_mtd_part_parser(__mtd_part_parser) \
  96         module_driver(__mtd_part_parser, register_mtd_parser, \
  97                       deregister_mtd_parser)
  98
  99 int mtd_is_partition(const struct mtd_info *mtd);
 100 int mtd_add_partition(struct mtd_info *master, const char *name,
 101                       long long offset, long long length);
 102 int mtd_del_partition(struct mtd_info *master, int partno);
 103 uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 104
 105 #endif