xref: /openbmc/linux/include/linux/mtd/mtd.h (revision fd589a8f)
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 #define MAX_MTD_DEVICES 32
24 
25 #define MTD_ERASE_PENDING      	0x01
26 #define MTD_ERASING		0x02
27 #define MTD_ERASE_SUSPEND	0x04
28 #define MTD_ERASE_DONE          0x08
29 #define MTD_ERASE_FAILED        0x10
30 
31 #define MTD_FAIL_ADDR_UNKNOWN -1LL
32 
33 /* If the erase fails, fail_addr might indicate exactly which block failed.  If
34    fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level or was not
35    specific to any particular block. */
36 struct erase_info {
37 	struct mtd_info *mtd;
38 	uint64_t addr;
39 	uint64_t len;
40 	uint64_t fail_addr;
41 	u_long time;
42 	u_long retries;
43 	unsigned dev;
44 	unsigned cell;
45 	void (*callback) (struct erase_info *self);
46 	u_long priv;
47 	u_char state;
48 	struct erase_info *next;
49 };
50 
51 struct mtd_erase_region_info {
52 	uint64_t offset;			/* At which this region starts, from the beginning of the MTD */
53 	uint32_t erasesize;		/* For this region */
54 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
55 	unsigned long *lockmap;		/* If keeping bitmap of locks */
56 };
57 
58 /*
59  * oob operation modes
60  *
61  * MTD_OOB_PLACE:	oob data are placed at the given offset
62  * MTD_OOB_AUTO:	oob data are automatically placed at the free areas
63  *			which are defined by the ecclayout
64  * MTD_OOB_RAW:		mode to read raw data+oob in one chunk. The oob data
65  *			is inserted into the data. Thats a raw image of the
66  *			flash contents.
67  */
68 typedef enum {
69 	MTD_OOB_PLACE,
70 	MTD_OOB_AUTO,
71 	MTD_OOB_RAW,
72 } mtd_oob_mode_t;
73 
74 /**
75  * struct mtd_oob_ops - oob operation operands
76  * @mode:	operation mode
77  *
78  * @len:	number of data bytes to write/read
79  *
80  * @retlen:	number of data bytes written/read
81  *
82  * @ooblen:	number of oob bytes to write/read
83  * @oobretlen:	number of oob bytes written/read
84  * @ooboffs:	offset of oob data in the oob area (only relevant when
85  *		mode = MTD_OOB_PLACE)
86  * @datbuf:	data buffer - if NULL only oob data are read/written
87  * @oobbuf:	oob data buffer
88  *
89  * Note, it is allowed to read more than one OOB area at one go, but not write.
90  * The interface assumes that the OOB write requests program only one page's
91  * OOB area.
92  */
93 struct mtd_oob_ops {
94 	mtd_oob_mode_t	mode;
95 	size_t		len;
96 	size_t		retlen;
97 	size_t		ooblen;
98 	size_t		oobretlen;
99 	uint32_t	ooboffs;
100 	uint8_t		*datbuf;
101 	uint8_t		*oobbuf;
102 };
103 
104 struct mtd_info {
105 	u_char type;
106 	uint32_t flags;
107 	uint64_t size;	 // Total size of the MTD
108 
109 	/* "Major" erase size for the device. Naïve users may take this
110 	 * to be the only erase size available, or may use the more detailed
111 	 * information below if they desire
112 	 */
113 	uint32_t erasesize;
114 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
115 	 * though individual bits can be cleared), in case of NAND flash it is
116 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
117 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
118 	 * Any driver registering a struct mtd_info must ensure a writesize of
119 	 * 1 or larger.
120 	 */
121 	uint32_t writesize;
122 
123 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
124 	uint32_t oobavail;  // Available OOB bytes per block
125 
126 	/*
127 	 * If erasesize is a power of 2 then the shift is stored in
128 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
129 	 */
130 	unsigned int erasesize_shift;
131 	unsigned int writesize_shift;
132 	/* Masks based on erasesize_shift and writesize_shift */
133 	unsigned int erasesize_mask;
134 	unsigned int writesize_mask;
135 
136 	// Kernel-only stuff starts here.
137 	const char *name;
138 	int index;
139 
140 	/* ecc layout structure pointer - read only ! */
141 	struct nand_ecclayout *ecclayout;
142 
143 	/* Data for variable erase regions. If numeraseregions is zero,
144 	 * it means that the whole device has erasesize as given above.
145 	 */
146 	int numeraseregions;
147 	struct mtd_erase_region_info *eraseregions;
148 
149 	/*
150 	 * Erase is an asynchronous operation.  Device drivers are supposed
151 	 * to call instr->callback() whenever the operation completes, even
152 	 * if it completes with a failure.
153 	 * Callers are supposed to pass a callback function and wait for it
154 	 * to be called before writing to the block.
155 	 */
156 	int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
157 
158 	/* This stuff for eXecute-In-Place */
159 	/* phys is optional and may be set to NULL */
160 	int (*point) (struct mtd_info *mtd, loff_t from, size_t len,
161 			size_t *retlen, void **virt, resource_size_t *phys);
162 
163 	/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
164 	void (*unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
165 
166 	/* Allow NOMMU mmap() to directly map the device (if not NULL)
167 	 * - return the address to which the offset maps
168 	 * - return -ENOSYS to indicate refusal to do the mapping
169 	 */
170 	unsigned long (*get_unmapped_area) (struct mtd_info *mtd,
171 					    unsigned long len,
172 					    unsigned long offset,
173 					    unsigned long flags);
174 
175 	/* Backing device capabilities for this device
176 	 * - provides mmap capabilities
177 	 */
178 	struct backing_dev_info *backing_dev_info;
179 
180 
181 	int (*read) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
182 	int (*write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
183 
184 	/* In blackbox flight recorder like scenarios we want to make successful
185 	   writes in interrupt context. panic_write() is only intended to be
186 	   called when its known the kernel is about to panic and we need the
187 	   write to succeed. Since the kernel is not going to be running for much
188 	   longer, this function can break locks and delay to ensure the write
189 	   succeeds (but not sleep). */
190 
191 	int (*panic_write) (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
192 
193 	int (*read_oob) (struct mtd_info *mtd, loff_t from,
194 			 struct mtd_oob_ops *ops);
195 	int (*write_oob) (struct mtd_info *mtd, loff_t to,
196 			 struct mtd_oob_ops *ops);
197 
198 	/*
199 	 * Methods to access the protection register area, present in some
200 	 * flash devices. The user data is one time programmable but the
201 	 * factory data is read only.
202 	 */
203 	int (*get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
204 	int (*read_fact_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
205 	int (*get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf, size_t len);
206 	int (*read_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
207 	int (*write_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
208 	int (*lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len);
209 
210 	/* kvec-based read/write methods.
211 	   NB: The 'count' parameter is the number of _vectors_, each of
212 	   which contains an (ofs, len) tuple.
213 	*/
214 	int (*writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
215 
216 	/* Sync */
217 	void (*sync) (struct mtd_info *mtd);
218 
219 	/* Chip-supported device locking */
220 	int (*lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
221 	int (*unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
222 
223 	/* Power Management functions */
224 	int (*suspend) (struct mtd_info *mtd);
225 	void (*resume) (struct mtd_info *mtd);
226 
227 	/* Bad block management functions */
228 	int (*block_isbad) (struct mtd_info *mtd, loff_t ofs);
229 	int (*block_markbad) (struct mtd_info *mtd, loff_t ofs);
230 
231 	struct notifier_block reboot_notifier;  /* default mode before reboot */
232 
233 	/* ECC status information */
234 	struct mtd_ecc_stats ecc_stats;
235 	/* Subpage shift (NAND) */
236 	int subpage_sft;
237 
238 	void *priv;
239 
240 	struct module *owner;
241 	struct device dev;
242 	int usecount;
243 
244 	/* If the driver is something smart, like UBI, it may need to maintain
245 	 * its own reference counting. The below functions are only for driver.
246 	 * The driver may register its callbacks. These callbacks are not
247 	 * supposed to be called by MTD users */
248 	int (*get_device) (struct mtd_info *mtd);
249 	void (*put_device) (struct mtd_info *mtd);
250 };
251 
252 static inline struct mtd_info *dev_to_mtd(struct device *dev)
253 {
254 	return dev ? dev_get_drvdata(dev) : NULL;
255 }
256 
257 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
258 {
259 	if (mtd->erasesize_shift)
260 		return sz >> mtd->erasesize_shift;
261 	do_div(sz, mtd->erasesize);
262 	return sz;
263 }
264 
265 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
266 {
267 	if (mtd->erasesize_shift)
268 		return sz & mtd->erasesize_mask;
269 	return do_div(sz, mtd->erasesize);
270 }
271 
272 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
273 {
274 	if (mtd->writesize_shift)
275 		return sz >> mtd->writesize_shift;
276 	do_div(sz, mtd->writesize);
277 	return sz;
278 }
279 
280 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
281 {
282 	if (mtd->writesize_shift)
283 		return sz & mtd->writesize_mask;
284 	return do_div(sz, mtd->writesize);
285 }
286 
287 	/* Kernel-side ioctl definitions */
288 
289 extern int add_mtd_device(struct mtd_info *mtd);
290 extern int del_mtd_device (struct mtd_info *mtd);
291 
292 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
293 extern struct mtd_info *get_mtd_device_nm(const char *name);
294 
295 extern void put_mtd_device(struct mtd_info *mtd);
296 
297 
298 struct mtd_notifier {
299 	void (*add)(struct mtd_info *mtd);
300 	void (*remove)(struct mtd_info *mtd);
301 	struct list_head list;
302 };
303 
304 
305 extern void register_mtd_user (struct mtd_notifier *new);
306 extern int unregister_mtd_user (struct mtd_notifier *old);
307 
308 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
309 		       unsigned long count, loff_t to, size_t *retlen);
310 
311 int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
312 		      unsigned long count, loff_t from, size_t *retlen);
313 
314 #ifdef CONFIG_MTD_PARTITIONS
315 void mtd_erase_callback(struct erase_info *instr);
316 #else
317 static inline void mtd_erase_callback(struct erase_info *instr)
318 {
319 	if (instr->callback)
320 		instr->callback(instr);
321 }
322 #endif
323 
324 /*
325  * Debugging macro and defines
326  */
327 #define MTD_DEBUG_LEVEL0	(0)	/* Quiet   */
328 #define MTD_DEBUG_LEVEL1	(1)	/* Audible */
329 #define MTD_DEBUG_LEVEL2	(2)	/* Loud    */
330 #define MTD_DEBUG_LEVEL3	(3)	/* Noisy   */
331 
332 #ifdef CONFIG_MTD_DEBUG
333 #define DEBUG(n, args...)				\
334 	do {						\
335 		if (n <= CONFIG_MTD_DEBUG_VERBOSE)	\
336 			printk(KERN_INFO args);		\
337 	} while(0)
338 #else /* CONFIG_MTD_DEBUG */
339 #define DEBUG(n, args...)				\
340 	do {						\
341 		if (0)					\
342 			printk(KERN_INFO args);		\
343 	} while(0)
344 
345 #endif /* CONFIG_MTD_DEBUG */
346 
347 #endif /* __MTD_MTD_H__ */
348