linux/mtd/partitions.h

0001 /*
0002  * MTD partitioning layer definitions
0003  *
0004  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
0005  *
0006  * This code is GPL
0007  */
0008
0009 #ifndef MTD_PARTITIONS_H
0010 #define MTD_PARTITIONS_H
0011
0012 #include <linux/types.h>
0013
0014
0015 /*
0016  * Partition definition structure:
0017  *
0018  * An array of struct partition is passed along with a MTD object to
0019  * mtd_device_register() to create them.
0020  *
0021  * For each partition, these fields are available:
0022  * name: string that will be used to label the partition's MTD device.
0023  * types: some partitions can be containers using specific format to describe
0024  *  embedded subpartitions / volumes. E.g. many home routers use "firmware"
0025  *  partition that contains at least kernel and rootfs. In such case an
0026  *  extra parser is needed that will detect these dynamic partitions and
0027  *  report them to the MTD subsystem. If set this property stores an array
0028  *  of parser names to use when looking for subpartitions.
0029  * size: the partition size; if defined as MTDPART_SIZ_FULL, the partition
0030  *  will extend to the end of the master MTD device.
0031  * offset: absolute starting position within the master MTD device; if
0032  *  defined as MTDPART_OFS_APPEND, the partition will start where the
0033  *  previous one ended; if MTDPART_OFS_NXTBLK, at the next erase block;
0034  *  if MTDPART_OFS_RETAIN, consume as much as possible, leaving size
0035  *  after the end of partition.
0036  * mask_flags: contains flags that have to be masked (removed) from the
0037  *  master MTD flag set for the corresponding MTD partition.
0038  *  For example, to force a read-only partition, simply adding
0039  *  MTD_WRITEABLE to the mask_flags will do the trick.
0040  * add_flags: contains flags to add to the parent flags
0041  *
0042  * Note: writeable partitions require their size and offset be
0043  * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
0044  */
0045
0046 struct mtd_partition {
0047     const char *name;       /* identifier string */
0048     const char *const *types;   /* names of parsers to use if any */
0049     uint64_t size;          /* partition size */
0050     uint64_t offset;        /* offset within the master MTD space */
0051     uint32_t mask_flags;        /* master MTD flags to mask out for this partition */
0052     uint32_t add_flags;     /* flags to add to the partition */
0053     struct device_node *of_node;
0054 };
0055
0056 #define MTDPART_OFS_RETAIN  (-3)
0057 #define MTDPART_OFS_NXTBLK  (-2)
0058 #define MTDPART_OFS_APPEND  (-1)
0059 #define MTDPART_SIZ_FULL    (0)
0060
0061
0062 struct mtd_info;
0063 struct device_node;
0064
0065 /**
0066  * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
0067  * @origin: for RedBoot, start address of MTD device
0068  */
0069 struct mtd_part_parser_data {
0070     unsigned long origin;
0071 };
0072
0073
0074 /*
0075  * Functions dealing with the various ways of partitioning the space
0076  */
0077
0078 struct mtd_part_parser {
0079     struct list_head list;
0080     struct module *owner;
0081     const char *name;
0082     const struct of_device_id *of_match_table;
0083     int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
0084             struct mtd_part_parser_data *);
0085     void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
0086 };
0087
0088 /* Container for passing around a set of parsed partitions */
0089 struct mtd_partitions {
0090     const struct mtd_partition *parts;
0091     int nr_parts;
0092     const struct mtd_part_parser *parser;
0093 };
0094
0095 extern int __register_mtd_parser(struct mtd_part_parser *parser,
0096                  struct module *owner);
0097 #define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
0098
0099 extern void deregister_mtd_parser(struct mtd_part_parser *parser);
0100
0101 /*
0102  * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
0103  * do anything special in module init/exit. Each driver may only use this macro
0104  * once, and calling it replaces module_init() and module_exit().
0105  */
0106 #define module_mtd_part_parser(__mtd_part_parser) \
0107     module_driver(__mtd_part_parser, register_mtd_parser, \
0108               deregister_mtd_parser)
0109
0110 int mtd_add_partition(struct mtd_info *master, const char *name,
0111               long long offset, long long length);
0112 int mtd_del_partition(struct mtd_info *master, int partno);
0113 uint64_t mtd_get_device_size(const struct mtd_info *mtd);
0114
0115 #endif