xref: /linux/include/linux/mtd/mtd.h (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  *
18  */
19 
20 #ifndef __MTD_MTD_H__
21 #define __MTD_MTD_H__
22 
23 #include <linux/types.h>
24 #include <linux/module.h>
25 #include <linux/uio.h>
26 #include <linux/notifier.h>
27 #include <linux/device.h>
28 
29 #include <mtd/mtd-abi.h>
30 
31 #include <asm/div64.h>
32 
33 #define MTD_CHAR_MAJOR 90
34 #define MTD_BLOCK_MAJOR 31
35 
36 #define MTD_ERASE_PENDING      	0x01
37 #define MTD_ERASING		0x02
38 #define MTD_ERASE_SUSPEND	0x04
39 #define MTD_ERASE_DONE          0x08
40 #define MTD_ERASE_FAILED        0x10
41 
42 #define MTD_FAIL_ADDR_UNKNOWN -1LL
43 
44 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
45    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
46    specific to any particular block. */
47 struct erase_info {
48 	struct mtd_info *mtd;
49 	uint64_t addr;
50 	uint64_t len;
51 	uint64_t fail_addr;
52 	u_long time;
53 	u_long retries;
54 	unsigned dev;
55 	unsigned cell;
56 	void (*callback) (struct erase_info *self);
57 	u_long priv;
58 	u_char state;
59 	struct erase_info *next;
60 };
61 
62 struct mtd_erase_region_info {
63 	uint64_t offset;			/* At which this region starts, from the beginning of the MTD */
64 	uint32_t erasesize;		/* For this region */
65 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
66 	unsigned long *lockmap;		/* If keeping bitmap of locks */
67 };
68 
69 /*
70  * oob operation modes
71  *
72  * MTD_OOB_PLACE:	oob data are placed at the given offset
73  * MTD_OOB_AUTO:	oob data are automatically placed at the free areas
74  *			which are defined by the ecclayout
75  * MTD_OOB_RAW:		mode to read oob and data without doing ECC checking
76  */
77 typedef enum {
78 	MTD_OOB_PLACE,
79 	MTD_OOB_AUTO,
80 	MTD_OOB_RAW,
81 } mtd_oob_mode_t;
82 
83 /**
84  * struct mtd_oob_ops - oob operation operands
85  * @mode:	operation mode
86  *
87  * @len:	number of data bytes to write/read
88  *
89  * @retlen:	number of data bytes written/read
90  *
91  * @ooblen:	number of oob bytes to write/read
92  * @oobretlen:	number of oob bytes written/read
93  * @ooboffs:	offset of oob data in the oob area (only relevant when
94  *		mode = MTD_OOB_PLACE)
95  * @datbuf:	data buffer - if NULL only oob data are read/written
96  * @oobbuf:	oob data buffer
97  *
98  * Note, it is allowed to read more than one OOB area at one go, but not write.
99  * The interface assumes that the OOB write requests program only one page's
100  * OOB area.
101  */
102 struct mtd_oob_ops {
103 	mtd_oob_mode_t	mode;
104 	size_t		len;
105 	size_t		retlen;
106 	size_t		ooblen;
107 	size_t		oobretlen;
108 	uint32_t	ooboffs;
109 	uint8_t		*datbuf;
110 	uint8_t		*oobbuf;
111 };
112 
113 struct mtd_info {
114 	u_char type;
115 	uint32_t flags;
116 	uint64_t size;	 // Total size of the MTD
117 
118 	/* "Major" erase size for the device. Naïve users may take this
119 	 * to be the only erase size available, or may use the more detailed
120 	 * information below if they desire
121 	 */
122 	uint32_t erasesize;
123 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
124 	 * though individual bits can be cleared), in case of NAND flash it is
125 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
126 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
127 	 * Any driver registering a struct mtd_info must ensure a writesize of
128 	 * 1 or larger.
129 	 */
130 	uint32_t writesize;
131 
132 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
133 	uint32_t oobavail;  // Available OOB bytes per block
134 
135 	/*
136 	 * If erasesize is a power of 2 then the shift is stored in
137 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
138 	 */
139 	unsigned int erasesize_shift;
140 	unsigned int writesize_shift;
141 	/* Masks based on erasesize_shift and writesize_shift */
142 	unsigned int erasesize_mask;
143 	unsigned int writesize_mask;
144 
145 	// Kernel-only stuff starts here.
146 	const char *name;
147 	int index;
148 
149 	/* ecc layout structure pointer - read only ! */
150 	struct nand_ecclayout *ecclayout;
151 
152 	/* Data for variable erase regions. If numeraseregions is zero,
153 	 * it means that the whole device has erasesize as given above.
154 	 */
155 	int numeraseregions;
156 	struct mtd_erase_region_info *eraseregions;
157 
158 	/*
159 	 * Erase is an asynchronous operation.  Device drivers are supposed
160 	 * to call instr->callback() whenever the operation completes, even
161 	 * if it completes with a failure.
162 	 * Callers are supposed to pass a callback function and wait for it
163 	 * to be called before writing to the block.
164 	 */
165 	int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
166 
167 	/* This stuff for eXecute-In-Place */
168 	/* phys is optional and may be set to NULL */
169 	int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
170 			size_t *retlen, void **virt, resource_size_t *phys);
171 
172 	/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
173 	void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
174 
175 	/* Allow NOMMU mmap() to directly map the device (if not NULL)
176 	 * - return the address to which the offset maps
177 	 * - return -ENOSYS to indicate refusal to do the mapping
178 	 */
179 	unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
180 					    unsigned long len,
181 					    unsigned long offset,
182 					    unsigned long flags);
183 
184 	/* Backing device capabilities for this device
185 	 * - provides mmap capabilities
186 	 */
187 	struct backing_dev_info *backing_dev_info;
188 
189 
190 	int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
191 	int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
192 
193 	/* In blackbox flight recorder like scenarios we want to make successful
194 	   writes in interrupt context. panic_write() is only intended to be
195 	   called when its known the kernel is about to panic and we need the
196 	   write to succeed. Since the kernel is not going to be running for much
197 	   longer, this function can break locks and delay to ensure the write
198 	   succeeds (but not sleep). */
199 
200 	int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
201 
202 	int (*read_oob) (struct mtd_info *mtd, loff_t from,
203 			 struct mtd_oob_ops *ops);
204 	int (*write_oob) (struct mtd_info *mtd, loff_t to,
205 			 struct mtd_oob_ops *ops);
206 
207 	/*
208 	 * Methods to access the protection register area, present in some
209 	 * flash devices. The user data is one time programmable but the
210 	 * factory data is read only.
211 	 */
212 	int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
213 	int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
214 	int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
215 	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
216 	int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
217 	int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
218 
219 	/* kvec-based read/write methods.
220 	   NB: The 'count' parameter is the number of _vectors_, each of
221 	   which contains an (ofs, len) tuple.
222 	*/
223 	int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
224 
225 	/* Sync */
226 	void (*sync) (struct mtd_info *mtd);
227 
228 	/* Chip-supported device locking */
229 	int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
230 	int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
231 	int (*is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
232 
233 	/* Power Management functions */
234 	int (*suspend) (struct mtd_info *mtd);
235 	void (*resume) (struct mtd_info *mtd);
236 
237 	/* Bad block management functions */
238 	int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
239 	int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
240 
241 	struct notifier_block reboot_notifier;  /* default mode before reboot */
242 
243 	/* ECC status information */
244 	struct mtd_ecc_stats ecc_stats;
245 	/* Subpage shift (NAND) */
246 	int subpage_sft;
247 
248 	void *priv;
249 
250 	struct module *owner;
251 	struct device dev;
252 	int usecount;
253 
254 	/* If the driver is something smart, like UBI, it may need to maintain
255 	 * its own reference counting. The below functions are only for driver.
256 	 * The driver may register its callbacks. These callbacks are not
257 	 * supposed to be called by MTD users */
258 	int (*get_device) (struct mtd_info *mtd);
259 	void (*put_device) (struct mtd_info *mtd);
260 };
261 
262 static inline struct mtd_info *dev_to_mtd(struct device *dev)
263 {
264 	return dev ? dev_get_drvdata(dev) : NULL;
265 }
266 
267 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
268 {
269 	if (mtd->erasesize_shift)
270 		return sz >> mtd->erasesize_shift;
271 	do_div(sz, mtd->erasesize);
272 	return sz;
273 }
274 
275 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
276 {
277 	if (mtd->erasesize_shift)
278 		return sz & mtd->erasesize_mask;
279 	return do_div(sz, mtd->erasesize);
280 }
281 
282 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
283 {
284 	if (mtd->writesize_shift)
285 		return sz >> mtd->writesize_shift;
286 	do_div(sz, mtd->writesize);
287 	return sz;
288 }
289 
290 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
291 {
292 	if (mtd->writesize_shift)
293 		return sz & mtd->writesize_mask;
294 	return do_div(sz, mtd->writesize);
295 }
296 
297 	/* Kernel-side ioctl definitions */
298 
299 extern int add_mtd_device(struct mtd_info *mtd);
300 extern int del_mtd_device (struct mtd_info *mtd);
301 
302 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
303 extern int __get_mtd_device(struct mtd_info *mtd);
304 extern void __put_mtd_device(struct mtd_info *mtd);
305 extern struct mtd_info *get_mtd_device_nm(const char *name);
306 extern void put_mtd_device(struct mtd_info *mtd);
307 
308 
309 struct mtd_notifier {
310 	void (*add)(struct mtd_info *mtd);
311 	void (*remove)(struct mtd_info *mtd);
312 	struct list_head list;
313 };
314 
315 
316 extern void register_mtd_user (struct mtd_notifier *new);
317 extern int unregister_mtd_user (struct mtd_notifier *old);
318 
319 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
320 		       unsigned long count, loff_t to, size_t *retlen);
321 
322 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
323 		      unsigned long count, loff_t from, size_t *retlen);
324 
325 #ifdef CONFIG_MTD_PARTITIONS
326 void mtd_erase_callback(struct erase_info *instr);
327 #else
328 static inline void mtd_erase_callback(struct erase_info *instr)
329 {
330 	if (instr->callback)
331 		instr->callback(instr);
332 }
333 #endif
334 
335 /*
336  * Debugging macro and defines
337  */
338 #define MTD_DEBUG_LEVEL0	(0)	/* Quiet   */
339 #define MTD_DEBUG_LEVEL1	(1)	/* Audible */
340 #define MTD_DEBUG_LEVEL2	(2)	/* Loud    */
341 #define MTD_DEBUG_LEVEL3	(3)	/* Noisy   */
342 
343 #ifdef CONFIG_MTD_DEBUG
344 #define DEBUG(n, args...)				\
345 	do {						\
346 		if (n <= CONFIG_MTD_DEBUG_VERBOSE)	\
347 			printk(KERN_INFO args);		\
348 	} while(0)
349 #else /* CONFIG_MTD_DEBUG */
350 #define DEBUG(n, args...)				\
351 	do {						\
352 		if (0)					\
353 			printk(KERN_INFO args);		\
354 	} while(0)
355 
356 #endif /* CONFIG_MTD_DEBUG */
357 
358 #endif /* __MTD_MTD_H__ */
359