xref: /linux/include/linux/mtd/partitions.h (revision d99ff463ecf651437e9e4abe68f331dfb6b5bd9d)
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 
46 struct 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 
62 struct mtd_info;
63 struct 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  */
69 struct 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 
78 struct 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 */
89 struct mtd_partitions {
90 	const struct mtd_partition *parts;
91 	int nr_parts;
92 	const struct mtd_part_parser *parser;
93 };
94 
95 extern 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 
99 extern 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 
110 int mtd_add_partition(struct mtd_info *master, const char *name,
111 		      long long offset, long long length);
112 int mtd_del_partition(struct mtd_info *master, int partno);
113 uint64_t mtd_get_device_size(const struct mtd_info *mtd);
114 
115 #endif
116