xref: /linux/include/linux/mtd/mtd.h (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
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 #include <linux/device.h>
15 
16 #include <linux/mtd/compatmac.h>
17 #include <mtd/mtd-abi.h>
18 
19 #include <asm/div64.h>
20 
21 #define MTD_CHAR_MAJOR 90
22 #define MTD_BLOCK_MAJOR 31
23 
24 #define MTD_ERASE_PENDING      	0x01
25 #define MTD_ERASING		0x02
26 #define MTD_ERASE_SUSPEND	0x04
27 #define MTD_ERASE_DONE          0x08
28 #define MTD_ERASE_FAILED        0x10
29 
30 #define MTD_FAIL_ADDR_UNKNOWN -1LL
31 
32 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
33    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
34    specific to any particular block. */
35 struct erase_info {
36 	struct mtd_info *mtd;
37 	uint64_t addr;
38 	uint64_t len;
39 	uint64_t fail_addr;
40 	u_long time;
41 	u_long retries;
42 	unsigned dev;
43 	unsigned cell;
44 	void (*callback) (struct erase_info *self);
45 	u_long priv;
46 	u_char state;
47 	struct erase_info *next;
48 };
49 
50 struct mtd_erase_region_info {
51 	uint64_t offset;			/* At which this region starts, from the beginning of the MTD */
52 	uint32_t erasesize;		/* For this region */
53 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
54 	unsigned long *lockmap;		/* If keeping bitmap of locks */
55 };
56 
57 /*
58  * oob operation modes
59  *
60  * MTD_OOB_PLACE:	oob data are placed at the given offset
61  * MTD_OOB_AUTO:	oob data are automatically placed at the free areas
62  *			which are defined by the ecclayout
63  * MTD_OOB_RAW:		mode to read oob and data without doing ECC checking
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 than 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 	uint32_t flags;
104 	uint64_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 	uint32_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 	uint32_t writesize;
119 
120 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
121 	uint32_t oobavail;  // Available OOB bytes per block
122 
123 	/*
124 	 * If erasesize is a power of 2 then the shift is stored in
125 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
126 	 */
127 	unsigned int erasesize_shift;
128 	unsigned int writesize_shift;
129 	/* Masks based on erasesize_shift and writesize_shift */
130 	unsigned int erasesize_mask;
131 	unsigned int writesize_mask;
132 
133 	// Kernel-only stuff starts here.
134 	const char *name;
135 	int index;
136 
137 	/* ecc layout structure pointer - read only ! */
138 	struct nand_ecclayout *ecclayout;
139 
140 	/* Data for variable erase regions. If numeraseregions is zero,
141 	 * it means that the whole device has erasesize as given above.
142 	 */
143 	int numeraseregions;
144 	struct mtd_erase_region_info *eraseregions;
145 
146 	/*
147 	 * Erase is an asynchronous operation.  Device drivers are supposed
148 	 * to call instr->callback() whenever the operation completes, even
149 	 * if it completes with a failure.
150 	 * Callers are supposed to pass a callback function and wait for it
151 	 * to be called before writing to the block.
152 	 */
153 	int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
154 
155 	/* This stuff for eXecute-In-Place */
156 	/* phys is optional and may be set to NULL */
157 	int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
158 			size_t *retlen, void **virt, resource_size_t *phys);
159 
160 	/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
161 	void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
162 
163 	/* Allow NOMMU mmap() to directly map the device (if not NULL)
164 	 * - return the address to which the offset maps
165 	 * - return -ENOSYS to indicate refusal to do the mapping
166 	 */
167 	unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
168 					    unsigned long len,
169 					    unsigned long offset,
170 					    unsigned long flags);
171 
172 	/* Backing device capabilities for this device
173 	 * - provides mmap capabilities
174 	 */
175 	struct backing_dev_info *backing_dev_info;
176 
177 
178 	int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
179 	int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
180 
181 	/* In blackbox flight recorder like scenarios we want to make successful
182 	   writes in interrupt context. panic_write() is only intended to be
183 	   called when its known the kernel is about to panic and we need the
184 	   write to succeed. Since the kernel is not going to be running for much
185 	   longer, this function can break locks and delay to ensure the write
186 	   succeeds (but not sleep). */
187 
188 	int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
189 
190 	int (*read_oob) (struct mtd_info *mtd, loff_t from,
191 			 struct mtd_oob_ops *ops);
192 	int (*write_oob) (struct mtd_info *mtd, loff_t to,
193 			 struct mtd_oob_ops *ops);
194 
195 	/*
196 	 * Methods to access the protection register area, present in some
197 	 * flash devices. The user data is one time programmable but the
198 	 * factory data is read only.
199 	 */
200 	int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
201 	int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
202 	int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
203 	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
204 	int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
205 	int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
206 
207 	/* kvec-based read/write methods.
208 	   NB: The 'count' parameter is the number of _vectors_, each of
209 	   which contains an (ofs, len) tuple.
210 	*/
211 	int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
212 
213 	/* Sync */
214 	void (*sync) (struct mtd_info *mtd);
215 
216 	/* Chip-supported device locking */
217 	int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
218 	int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
219 
220 	/* Power Management functions */
221 	int (*suspend) (struct mtd_info *mtd);
222 	void (*resume) (struct mtd_info *mtd);
223 
224 	/* Bad block management functions */
225 	int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
226 	int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
227 
228 	struct notifier_block reboot_notifier;  /* default mode before reboot */
229 
230 	/* ECC status information */
231 	struct mtd_ecc_stats ecc_stats;
232 	/* Subpage shift (NAND) */
233 	int subpage_sft;
234 
235 	void *priv;
236 
237 	struct module *owner;
238 	struct device dev;
239 	int usecount;
240 
241 	/* If the driver is something smart, like UBI, it may need to maintain
242 	 * its own reference counting. The below functions are only for driver.
243 	 * The driver may register its callbacks. These callbacks are not
244 	 * supposed to be called by MTD users */
245 	int (*get_device) (struct mtd_info *mtd);
246 	void (*put_device) (struct mtd_info *mtd);
247 };
248 
249 static inline struct mtd_info *dev_to_mtd(struct device *dev)
250 {
251 	return dev ? dev_get_drvdata(dev) : NULL;
252 }
253 
254 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
255 {
256 	if (mtd->erasesize_shift)
257 		return sz >> mtd->erasesize_shift;
258 	do_div(sz, mtd->erasesize);
259 	return sz;
260 }
261 
262 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
263 {
264 	if (mtd->erasesize_shift)
265 		return sz & mtd->erasesize_mask;
266 	return do_div(sz, mtd->erasesize);
267 }
268 
269 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
270 {
271 	if (mtd->writesize_shift)
272 		return sz >> mtd->writesize_shift;
273 	do_div(sz, mtd->writesize);
274 	return sz;
275 }
276 
277 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
278 {
279 	if (mtd->writesize_shift)
280 		return sz & mtd->writesize_mask;
281 	return do_div(sz, mtd->writesize);
282 }
283 
284 	/* Kernel-side ioctl definitions */
285 
286 extern int add_mtd_device(struct mtd_info *mtd);
287 extern int del_mtd_device (struct mtd_info *mtd);
288 
289 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
290 extern int __get_mtd_device(struct mtd_info *mtd);
291 extern void __put_mtd_device(struct mtd_info *mtd);
292 extern struct mtd_info *get_mtd_device_nm(const char *name);
293 extern void put_mtd_device(struct mtd_info *mtd);
294 
295 
296 struct mtd_notifier {
297 	void (*add)(struct mtd_info *mtd);
298 	void (*remove)(struct mtd_info *mtd);
299 	struct list_head list;
300 };
301 
302 
303 extern void register_mtd_user (struct mtd_notifier *new);
304 extern int unregister_mtd_user (struct mtd_notifier *old);
305 
306 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
307 		       unsigned long count, loff_t to, size_t *retlen);
308 
309 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
310 		      unsigned long count, loff_t from, size_t *retlen);
311 
312 #ifdef CONFIG_MTD_PARTITIONS
313 void mtd_erase_callback(struct erase_info *instr);
314 #else
315 static inline void mtd_erase_callback(struct erase_info *instr)
316 {
317 	if (instr->callback)
318 		instr->callback(instr);
319 }
320 #endif
321 
322 /*
323  * Debugging macro and defines
324  */
325 #define MTD_DEBUG_LEVEL0	(0)	/* Quiet   */
326 #define MTD_DEBUG_LEVEL1	(1)	/* Audible */
327 #define MTD_DEBUG_LEVEL2	(2)	/* Loud    */
328 #define MTD_DEBUG_LEVEL3	(3)	/* Noisy   */
329 
330 #ifdef CONFIG_MTD_DEBUG
331 #define DEBUG(n, args...)				\
332 	do {						\
333 		if (n <= CONFIG_MTD_DEBUG_VERBOSE)	\
334 			printk(KERN_INFO args);		\
335 	} while(0)
336 #else /* CONFIG_MTD_DEBUG */
337 #define DEBUG(n, args...)				\
338 	do {						\
339 		if (0)					\
340 			printk(KERN_INFO args);		\
341 	} while(0)
342 
343 #endif /* CONFIG_MTD_DEBUG */
344 
345 #endif /* __MTD_MTD_H__ */
346