xref: /linux/include/linux/mtd/partitions.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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
107