LXR linux/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
  45struct 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
  60struct mtd_info;
  61struct 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 */
  67struct 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
  76struct mtd_part_parser {
  77        struct list_head list;
  78        struct module *owner;
  79        const char *name;
  80        const struct of_device_id *of_match_table;
  81        int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
  82                        struct mtd_part_parser_data *);
  83        void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
  84};
  85
  86/* Container for passing around a set of parsed partitions */
  87struct mtd_partitions {
  88        const struct mtd_partition *parts;
  89        int nr_parts;
  90        const struct mtd_part_parser *parser;
  91};
  92
  93extern int __register_mtd_parser(struct mtd_part_parser *parser,
  94                                 struct module *owner);
  95#define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
  96
  97extern void deregister_mtd_parser(struct mtd_part_parser *parser);
  98
  99/*
 100 * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
 101 * do anything special in module init/exit. Each driver may only use this macro
 102 * once, and calling it replaces module_init() and module_exit().
 103 */
 104#define module_mtd_part_parser(__mtd_part_parser) \
 105        module_driver(__mtd_part_parser, register_mtd_parser, \
 106                      deregister_mtd_parser)
 107
 108int mtd_is_partition(const struct mtd_info *mtd);
 109int mtd_add_partition(struct mtd_info *master, const char *name,
 110                      long long offset, long long length);
 111int mtd_del_partition(struct mtd_info *master, int partno);
 112uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 113
 114#endif
 115