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  * types: some partitions can be containers using specific format to describe
  24  *      embedded subpartitions / volumes. E.g. many home routers use "firmware"
  25  *      partition that contains at least kernel and rootfs. In such case an
  26  *      extra parser is needed that will detect these dynamic partitions and
  27  *      report them to the MTD subsystem. If set this property stores an array
  28  *      of parser names to use when looking for subpartitions.
  29  * size: the partition size; if defined as MTDPART_SIZ_FULL, the partition
  30  *      will extend to the end of the master MTD device.
  31  * offset: absolute starting position within the master MTD device; if
  32  *      defined as MTDPART_OFS_APPEND, the partition will start where the
  33  *      previous one ended; if MTDPART_OFS_NXTBLK, at the next erase block;
  34  *      if MTDPART_OFS_RETAIN, consume as much as possible, leaving size
  35  *      after the end of partition.
  36  * mask_flags: contains flags that have to be masked (removed) from the
  37  *      master MTD flag set for the corresponding MTD partition.
  38  *      For example, to force a read-only partition, simply adding
  39  *      MTD_WRITEABLE to the mask_flags will do the trick.
  40  *
  41  * Note: writeable partitions require their size and offset be
  42  * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
  43  */
  44
  45 struct mtd_partition {
  46         const char *name;               /* identifier string */
  47         const char *const *types;       /* names of parsers to use if any */
  48         uint64_t size;                  /* partition size */
  49         uint64_t offset;                /* offset within the master MTD space */
  50         uint32_t mask_flags;            /* master MTD flags to mask out for this partition */
  51         struct device_node *of_node;
  52 };
  53
  54 #define MTDPART_OFS_RETAIN      (-3)
  55 #define MTDPART_OFS_NXTBLK      (-2)
  56 #define MTDPART_OFS_APPEND      (-1)
  57 #define MTDPART_SIZ_FULL        (0)
  58
  59
  60 struct mtd_info;
  61 struct device_node;
  62
  63 /**
  64  * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
  65  * @origin: for RedBoot, start address of MTD device
  66  */
  67 struct mtd_part_parser_data {
  68         unsigned long origin;
  69 };
  70
  71
  72 /*
  73  * Functions dealing with the various ways of partitioning the space
  74  */
  75
  76 struct mtd_part_parser {
  77         struct list_head list;
  78         struct module *owner;
  79         const char *name;
  80         int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
  81                         struct mtd_part_parser_data *);
  82         void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
  83 };
  84
  85 /* Container for passing around a set of parsed partitions */
  86 struct mtd_partitions {
  87         const struct mtd_partition *parts;
  88         int nr_parts;
  89         const struct mtd_part_parser *parser;
  90 };
  91
  92 extern int __register_mtd_parser(struct mtd_part_parser *parser,
  93                                  struct module *owner);
  94 #define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
  95
  96 extern void deregister_mtd_parser(struct mtd_part_parser *parser);
  97
  98 /*
  99  * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
 100  * do anything special in module init/exit. Each driver may only use this macro
 101  * once, and calling it replaces module_init() and module_exit().
 102  */
 103 #define module_mtd_part_parser(__mtd_part_parser) \
 104         module_driver(__mtd_part_parser, register_mtd_parser, \
 105                       deregister_mtd_parser)
 106
 107 int mtd_is_partition(const struct mtd_info *mtd);
 108 int mtd_add_partition(struct mtd_info *master, const char *name,
 109                       long long offset, long long length);
 110 int mtd_del_partition(struct mtd_info *master, int partno);
 111 uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 112
 113 #endif