xref: /linux/include/linux/mtd/mtd.h (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * Copyright (C) 1999-2003 David Woodhouse <dwmw2@infradead.org> et al.
3  *
4  * Released under GPL
5  */
6 
7 #ifndef __MTD_MTD_H__
8 #define __MTD_MTD_H__
9 
10 #include <linux/types.h>
11 #include <linux/module.h>
12 #include <linux/uio.h>
13 #include <linux/notifier.h>
14 
15 #include <linux/mtd/compatmac.h>
16 #include <mtd/mtd-abi.h>
17 
18 #define MTD_CHAR_MAJOR 90
19 #define MTD_BLOCK_MAJOR 31
20 #define MAX_MTD_DEVICES 32
21 
22 #define MTD_ERASE_PENDING      	0x01
23 #define MTD_ERASING		0x02
24 #define MTD_ERASE_SUSPEND	0x04
25 #define MTD_ERASE_DONE          0x08
26 #define MTD_ERASE_FAILED        0x10
27 
28 #define MTD_FAIL_ADDR_UNKNOWN 0xffffffff
29 
30 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
31    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
32    specific to any particular block. */
33 struct erase_info {
34 	struct mtd_info *mtd;
35 	u_int32_t addr;
36 	u_int32_t len;
37 	u_int32_t fail_addr;
38 	u_long time;
39 	u_long retries;
40 	u_int dev;
41 	u_int cell;
42 	void (*callback) (struct erase_info *self);
43 	u_long priv;
44 	u_char state;
45 	struct erase_info *next;
46 };
47 
48 struct mtd_erase_region_info {
49 	u_int32_t offset;			/* At which this region starts, from the beginning of the MTD */
50 	u_int32_t erasesize;		/* For this region */
51 	u_int32_t numblocks;		/* Number of blocks of erasesize in this region */
52 	unsigned long *lockmap;		/* If keeping bitmap of locks */
53 };
54 
55 /*
56  * oob operation modes
57  *
58  * MTD_OOB_PLACE:	oob data are placed at the given offset
59  * MTD_OOB_AUTO:	oob data are automatically placed at the free areas
60  *			which are defined by the ecclayout
61  * MTD_OOB_RAW:		mode to read raw data+oob in one chunk. The oob data
62  *			is inserted into the data. Thats a raw image of the
63  *			flash contents.
64  */
65 typedef enum {
66 	MTD_OOB_PLACE,
67 	MTD_OOB_AUTO,
68 	MTD_OOB_RAW,
69 } mtd_oob_mode_t;
70 
71 /**
72  * struct mtd_oob_ops - oob operation operands
73  * @mode:	operation mode
74  *
75  * @len:	number of data bytes to write/read
76  *
77  * @retlen:	number of data bytes written/read
78  *
79  * @ooblen:	number of oob bytes to write/read
80  * @oobretlen:	number of oob bytes written/read
81  * @ooboffs:	offset of oob data in the oob area (only relevant when
82  *		mode = MTD_OOB_PLACE)
83  * @datbuf:	data buffer - if NULL only oob data are read/written
84  * @oobbuf:	oob data buffer
85  *
86  * Note, it is allowed to read more then one OOB area at one go, but not write.
87  * The interface assumes that the OOB write requests program only one page's
88  * OOB area.
89  */
90 struct mtd_oob_ops {
91 	mtd_oob_mode_t	mode;
92 	size_t		len;
93 	size_t		retlen;
94 	size_t		ooblen;
95 	size_t		oobretlen;
96 	uint32_t	ooboffs;
97 	uint8_t		*datbuf;
98 	uint8_t		*oobbuf;
99 };
100 
101 struct mtd_info {
102 	u_char type;
103 	u_int32_t flags;
104 	u_int32_t size;	 // Total size of the MTD
105 
106 	/* "Major" erase size for the device. Naïve users may take this
107 	 * to be the only erase size available, or may use the more detailed
108 	 * information below if they desire
109 	 */
110 	u_int32_t erasesize;
111 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
112 	 * though individual bits can be cleared), in case of NAND flash it is
113 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
114 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
115 	 * Any driver registering a struct mtd_info must ensure a writesize of
116 	 * 1 or larger.
117 	 */
118 	u_int32_t writesize;
119 
120 	u_int32_t oobsize;   // Amount of OOB data per block (e.g. 16)
121 	u_int32_t oobavail;  // Available OOB bytes per block
122 
123 	// Kernel-only stuff starts here.
124 	const char *name;
125 	int index;
126 
127 	/* ecc layout structure pointer - read only ! */
128 	struct nand_ecclayout *ecclayout;
129 
130 	/* Data for variable erase regions. If numeraseregions is zero,
131 	 * it means that the whole device has erasesize as given above.
132 	 */
133 	int numeraseregions;
134 	struct mtd_erase_region_info *eraseregions;
135 
136 	/*
137 	 * Erase is an asynchronous operation.  Device drivers are supposed
138 	 * to call instr->callback() whenever the operation completes, even
139 	 * if it completes with a failure.
140 	 * Callers are supposed to pass a callback function and wait for it
141 	 * to be called before writing to the block.
142 	 */
143 	int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
144 
145 	/* This stuff for eXecute-In-Place */
146 	/* phys is optional and may be set to NULL */
147 	int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
148 			size_t *retlen, void **virt, resource_size_t *phys);
149 
150 	/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
151 	void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
152 
153 
154 	int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
155 	int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
156 
157 	/* In blackbox flight recorder like scenarios we want to make successful
158 	   writes in interrupt context. panic_write() is only intended to be
159 	   called when its known the kernel is about to panic and we need the
160 	   write to succeed. Since the kernel is not going to be running for much
161 	   longer, this function can break locks and delay to ensure the write
162 	   succeeds (but not sleep). */
163 
164 	int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
165 
166 	int (*read_oob) (struct mtd_info *mtd, loff_t from,
167 			 struct mtd_oob_ops *ops);
168 	int (*write_oob) (struct mtd_info *mtd, loff_t to,
169 			 struct mtd_oob_ops *ops);
170 
171 	/*
172 	 * Methods to access the protection register area, present in some
173 	 * flash devices. The user data is one time programmable but the
174 	 * factory data is read only.
175 	 */
176 	int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
177 	int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
178 	int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
179 	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
180 	int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
181 	int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
182 
183 	/* kvec-based read/write methods.
184 	   NB: The 'count' parameter is the number of _vectors_, each of
185 	   which contains an (ofs, len) tuple.
186 	*/
187 	int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
188 
189 	/* Sync */
190 	void (*sync) (struct mtd_info *mtd);
191 
192 	/* Chip-supported device locking */
193 	int (*lock) (struct mtd_info *mtd, loff_t ofs, size_t len);
194 	int (*unlock) (struct mtd_info *mtd, loff_t ofs, size_t len);
195 
196 	/* Power Management functions */
197 	int (*suspend) (struct mtd_info *mtd);
198 	void (*resume) (struct mtd_info *mtd);
199 
200 	/* Bad block management functions */
201 	int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
202 	int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
203 
204 	struct notifier_block reboot_notifier;  /* default mode before reboot */
205 
206 	/* ECC status information */
207 	struct mtd_ecc_stats ecc_stats;
208 	/* Subpage shift (NAND) */
209 	int subpage_sft;
210 
211 	void *priv;
212 
213 	struct module *owner;
214 	int usecount;
215 
216 	/* If the driver is something smart, like UBI, it may need to maintain
217 	 * its own reference counting. The below functions are only for driver.
218 	 * The driver may register its callbacks. These callbacks are not
219 	 * supposed to be called by MTD users */
220 	int (*get_device) (struct mtd_info *mtd);
221 	void (*put_device) (struct mtd_info *mtd);
222 };
223 
224 
225 	/* Kernel-side ioctl definitions */
226 
227 extern int add_mtd_device(struct mtd_info *mtd);
228 extern int del_mtd_device (struct mtd_info *mtd);
229 
230 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
231 extern struct mtd_info *get_mtd_device_nm(const char *name);
232 
233 extern void put_mtd_device(struct mtd_info *mtd);
234 
235 
236 struct mtd_notifier {
237 	void (*add)(struct mtd_info *mtd);
238 	void (*remove)(struct mtd_info *mtd);
239 	struct list_head list;
240 };
241 
242 
243 extern void register_mtd_user (struct mtd_notifier *new);
244 extern int unregister_mtd_user (struct mtd_notifier *old);
245 
246 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
247 		       unsigned long count, loff_t to, size_t *retlen);
248 
249 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
250 		      unsigned long count, loff_t from, size_t *retlen);
251 
252 #ifdef CONFIG_MTD_PARTITIONS
253 void mtd_erase_callback(struct erase_info *instr);
254 #else
255 static inline void mtd_erase_callback(struct erase_info *instr)
256 {
257 	if (instr->callback)
258 		instr->callback(instr);
259 }
260 #endif
261 
262 /*
263  * Debugging macro and defines
264  */
265 #define MTD_DEBUG_LEVEL0	(0)	/* Quiet   */
266 #define MTD_DEBUG_LEVEL1	(1)	/* Audible */
267 #define MTD_DEBUG_LEVEL2	(2)	/* Loud    */
268 #define MTD_DEBUG_LEVEL3	(3)	/* Noisy   */
269 
270 #ifdef CONFIG_MTD_DEBUG
271 #define DEBUG(n, args...)				\
272 	do {						\
273 		if (n <= CONFIG_MTD_DEBUG_VERBOSE)	\
274 			printk(KERN_INFO args);		\
275 	} while(0)
276 #else /* CONFIG_MTD_DEBUG */
277 #define DEBUG(n, args...)				\
278 	do {						\
279 		if (0)					\
280 			printk(KERN_INFO args);		\
281 	} while(0)
282 
283 #endif /* CONFIG_MTD_DEBUG */
284 
285 #endif /* __MTD_MTD_H__ */
286