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 * add_flags: contains flags to add to the parent flags
 41 *
 42 * Note: writeable partitions require their size and offset be
 43 * erasesize aligned (e.g. use MTDPART_OFS_NEXTBLK).
 44 */
 45
 46struct mtd_partition {
 47	const char *name;		/* identifier string */
 48	const char *const *types;	/* names of parsers to use if any */
 49	uint64_t size;			/* partition size */
 50	uint64_t offset;		/* offset within the master MTD space */
 51	uint32_t mask_flags;		/* master MTD flags to mask out for this partition */
 52	uint32_t add_flags;		/* flags to add to the partition */
 53	struct device_node *of_node;
 54};
 55
 56#define MTDPART_OFS_RETAIN	(-3)
 57#define MTDPART_OFS_NXTBLK	(-2)
 58#define MTDPART_OFS_APPEND	(-1)
 59#define MTDPART_SIZ_FULL	(0)
 60
 61
 62struct mtd_info;
 63struct device_node;
 64
 65/**
 66 * struct mtd_part_parser_data - used to pass data to MTD partition parsers.
 67 * @origin: for RedBoot, start address of MTD device
 68 */
 69struct mtd_part_parser_data {
 70	unsigned long origin;
 71};
 72
 73
 74/*
 75 * Functions dealing with the various ways of partitioning the space
 76 */
 77
 78struct mtd_part_parser {
 79	struct list_head list;
 80	struct module *owner;
 81	const char *name;
 82	const struct of_device_id *of_match_table;
 83	int (*parse_fn)(struct mtd_info *, const struct mtd_partition **,
 84			struct mtd_part_parser_data *);
 85	void (*cleanup)(const struct mtd_partition *pparts, int nr_parts);
 86};
 87
 88/* Container for passing around a set of parsed partitions */
 89struct mtd_partitions {
 90	const struct mtd_partition *parts;
 91	int nr_parts;
 92	const struct mtd_part_parser *parser;
 93};
 94
 95extern int __register_mtd_parser(struct mtd_part_parser *parser,
 96				 struct module *owner);
 97#define register_mtd_parser(parser) __register_mtd_parser(parser, THIS_MODULE)
 98
 99extern void deregister_mtd_parser(struct mtd_part_parser *parser);
100
101/*
102 * module_mtd_part_parser() - Helper macro for MTD partition parsers that don't
103 * do anything special in module init/exit. Each driver may only use this macro
104 * once, and calling it replaces module_init() and module_exit().
105 */
106#define module_mtd_part_parser(__mtd_part_parser) \
107	module_driver(__mtd_part_parser, register_mtd_parser, \
108		      deregister_mtd_parser)
109
110int mtd_add_partition(struct mtd_info *master, const char *name,
111		      long long offset, long long length);
112int mtd_del_partition(struct mtd_info *master, int partno);
113uint64_t mtd_get_device_size(const struct mtd_info *mtd);
114
115#endif