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         struct device_node *of_node;
  45 };
  46
  47 #define MTDPART_OFS_RETAIN      (-3)
  48 #define MTDPART_OFS_NXTBLK      (-2)
  49 #define MTDPART_OFS_APPEND      (-1)
  50 #define MTDPART_SIZ_FULL        (0)
  51
  52
  53 struct mtd_info;
  54 struct device_node;
  55
  56 /**
  57  * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
  58  * @origin: for RedBoot, start address of MTD device
  59  */
  60 struct mtd_part_parser_data {
  61         unsigned long origin;
  62 };
  63
  64
  65 /*
  66  * Functions dealing with the various ways of partitioning the space
  67  */
  68
  69 struct mtd_part_parser {
  70         struct list_head list;
  71         struct module *owner;
  72         const char *name;
  73         int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
  74                         struct mtd_part_parser_data *);
  75         void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
  76 };
  77
  78 /* Container for passing around a set of parsed partitions */
  79 struct mtd_partitions {
  80         const struct mtd_partition *parts;
  81         int nr_parts;
  82         const struct mtd_part_parser *parser;
  83 };
  84
  85 extern int __register_mtd_parser(struct mtd_part_parser *parser,
  86                                  struct module *owner);
  87 #define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
  88
  89 extern void deregister_mtd_parser(struct mtd_part_parser *parser);
  90
  91 /*
  92  * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
  93  * do anything special in module init/exit. Each driver may only use this macro
  94  * once, and calling it replaces module_init() and module_exit().
  95  */
  96 #define module_mtd_part_parser(__mtd_part_parser) \
  97         module_driver(__mtd_part_parser, register_mtd_parser, \
  98                       deregister_mtd_parser)
  99
 100 int mtd_is_partition(const struct mtd_info *mtd);
 101 int mtd_add_partition(struct mtd_info *master, const char *name,
 102                       long long offset, long long length);
 103 int mtd_del_partition(struct mtd_info *master, int partno);
 104 uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 105
 106 #endif