1 /*
2 * $Id: mtdcore.c,v 1.34 2003/01/24 23:32:25 dwmw2 Exp $
3 *
4 * Core registration and callback routines for MTD
5 * drivers and users.
6 *
7 */
8
9 #include <linux/config.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/ptrace.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/timer.h>
17 #include <linux/major.h>
18 #include <linux/fs.h>
19 #include <linux/ioctl.h>
20 #include <linux/mtd/compatmac.h>
21 #ifdef CONFIG_PROC_FS
22 #include <linux/proc_fs.h>
23 #endif
24
25 #include <linux/mtd/mtd.h>
26
27 static DECLARE_MUTEX(mtd_table_mutex);
28 static struct mtd_info *mtd_table[MAX_MTD_DEVICES];
29 static struct mtd_notifier *mtd_notifiers = NULL;
30
31 /**
32 * add_mtd_device - register an MTD device
33 * @mtd: pointer to new MTD device info structure
34 *
35 * Add a device to the list of MTD devices present in the system, and
36 * notify each currently active MTD 'user' of its arrival. Returns
37 * zero on success or 1 on failure, which currently will only happen
38 * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
39 */
40
add_mtd_device(struct mtd_info * mtd)41 int add_mtd_device(struct mtd_info *mtd)
42 {
43 int i;
44
45 down(&mtd_table_mutex);
46
47 for (i=0; i< MAX_MTD_DEVICES; i++)
48 if (!mtd_table[i])
49 {
50 struct mtd_notifier *not=mtd_notifiers;
51
52 mtd_table[i] = mtd;
53 mtd->index = i;
54 DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
55 while (not)
56 {
57 (*(not->add))(mtd);
58 not = not->next;
59 }
60 up(&mtd_table_mutex);
61 MOD_INC_USE_COUNT;
62 return 0;
63 }
64
65 up(&mtd_table_mutex);
66 return 1;
67 }
68
69 /**
70 * del_mtd_device - unregister an MTD device
71 * @mtd: pointer to MTD device info structure
72 *
73 * Remove a device from the list of MTD devices present in the system,
74 * and notify each currently active MTD 'user' of its departure.
75 * Returns zero on success or 1 on failure, which currently will happen
76 * if the requested device does not appear to be present in the list.
77 */
78
del_mtd_device(struct mtd_info * mtd)79 int del_mtd_device (struct mtd_info *mtd)
80 {
81 struct mtd_notifier *not=mtd_notifiers;
82 int i;
83
84 down(&mtd_table_mutex);
85
86 for (i=0; i < MAX_MTD_DEVICES; i++)
87 {
88 if (mtd_table[i] == mtd)
89 {
90 while (not)
91 {
92 (*(not->remove))(mtd);
93 not = not->next;
94 }
95 mtd_table[i] = NULL;
96 up (&mtd_table_mutex);
97 MOD_DEC_USE_COUNT;
98 return 0;
99 }
100 }
101
102 up(&mtd_table_mutex);
103 return 1;
104 }
105
106 /**
107 * register_mtd_user - register a 'user' of MTD devices.
108 * @new: pointer to notifier info structure
109 *
110 * Registers a pair of callbacks function to be called upon addition
111 * or removal of MTD devices. Causes the 'add' callback to be immediately
112 * invoked for each MTD device currently present in the system.
113 */
114
register_mtd_user(struct mtd_notifier * new)115 void register_mtd_user (struct mtd_notifier *new)
116 {
117 int i;
118
119 down(&mtd_table_mutex);
120
121 new->next = mtd_notifiers;
122 mtd_notifiers = new;
123
124 MOD_INC_USE_COUNT;
125
126 for (i=0; i< MAX_MTD_DEVICES; i++)
127 if (mtd_table[i])
128 new->add(mtd_table[i]);
129
130 up(&mtd_table_mutex);
131 }
132
133 /**
134 * register_mtd_user - unregister a 'user' of MTD devices.
135 * @new: pointer to notifier info structure
136 *
137 * Removes a callback function pair from the list of 'users' to be
138 * notified upon addition or removal of MTD devices. Causes the
139 * 'remove' callback to be immediately invoked for each MTD device
140 * currently present in the system.
141 */
142
unregister_mtd_user(struct mtd_notifier * old)143 int unregister_mtd_user (struct mtd_notifier *old)
144 {
145 struct mtd_notifier **prev = &mtd_notifiers;
146 struct mtd_notifier *cur;
147 int i;
148
149 down(&mtd_table_mutex);
150
151 while ((cur = *prev)) {
152 if (cur == old) {
153 *prev = cur->next;
154
155 MOD_DEC_USE_COUNT;
156
157 for (i=0; i< MAX_MTD_DEVICES; i++)
158 if (mtd_table[i])
159 old->remove(mtd_table[i]);
160
161 up(&mtd_table_mutex);
162 return 0;
163 }
164 prev = &cur->next;
165 }
166 up(&mtd_table_mutex);
167 return 1;
168 }
169
170
171 /**
172 * __get_mtd_device - obtain a validated handle for an MTD device
173 * @mtd: last known address of the required MTD device
174 * @num: internal device number of the required MTD device
175 *
176 * Given a number and NULL address, return the num'th entry in the device
177 * table, if any. Given an address and num == -1, search the device table
178 * for a device with that address and return if it's still present. Given
179 * both, return the num'th driver only if its address matches. Return NULL
180 * if not. get_mtd_device() increases the use count, but
181 * __get_mtd_device() doesn't - you should generally use get_mtd_device().
182 */
183
__get_mtd_device(struct mtd_info * mtd,int num)184 struct mtd_info *__get_mtd_device(struct mtd_info *mtd, int num)
185 {
186 struct mtd_info *ret = NULL;
187 int i;
188
189 down(&mtd_table_mutex);
190
191 if (num == -1) {
192 for (i=0; i< MAX_MTD_DEVICES; i++)
193 if (mtd_table[i] == mtd)
194 ret = mtd_table[i];
195 } else if (num < MAX_MTD_DEVICES) {
196 ret = mtd_table[num];
197 if (mtd && mtd != ret)
198 ret = NULL;
199 }
200
201 up(&mtd_table_mutex);
202 return ret;
203 }
204
205
206 /* default_mtd_writev - default mtd writev method for MTD devices that
207 * dont implement their own
208 */
209
default_mtd_writev(struct mtd_info * mtd,const struct iovec * vecs,unsigned long count,loff_t to,size_t * retlen)210 int default_mtd_writev(struct mtd_info *mtd, const struct iovec *vecs,
211 unsigned long count, loff_t to, size_t *retlen)
212 {
213 unsigned long i;
214 size_t totlen = 0, thislen;
215 int ret = 0;
216
217 if(!mtd->write) {
218 ret = -EROFS;
219 } else {
220 for (i=0; i<count; i++) {
221 if (!vecs[i].iov_len)
222 continue;
223 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
224 totlen += thislen;
225 if (ret || thislen != vecs[i].iov_len)
226 break;
227 to += vecs[i].iov_len;
228 }
229 }
230 if (retlen)
231 *retlen = totlen;
232 return ret;
233 }
234
235
236 /* default_mtd_readv - default mtd readv method for MTD devices that dont
237 * implement their own
238 */
239
default_mtd_readv(struct mtd_info * mtd,struct iovec * vecs,unsigned long count,loff_t from,size_t * retlen)240 int default_mtd_readv(struct mtd_info *mtd, struct iovec *vecs,
241 unsigned long count, loff_t from, size_t *retlen)
242 {
243 unsigned long i;
244 size_t totlen = 0, thislen;
245 int ret = 0;
246
247 if(!mtd->read) {
248 ret = -EIO;
249 } else {
250 for (i=0; i<count; i++) {
251 if (!vecs[i].iov_len)
252 continue;
253 ret = mtd->read(mtd, from, vecs[i].iov_len, &thislen, vecs[i].iov_base);
254 totlen += thislen;
255 if (ret || thislen != vecs[i].iov_len)
256 break;
257 from += vecs[i].iov_len;
258 }
259 }
260 if (retlen)
261 *retlen = totlen;
262 return ret;
263 }
264
265
266 EXPORT_SYMBOL(add_mtd_device);
267 EXPORT_SYMBOL(del_mtd_device);
268 EXPORT_SYMBOL(__get_mtd_device);
269 EXPORT_SYMBOL(register_mtd_user);
270 EXPORT_SYMBOL(unregister_mtd_user);
271 EXPORT_SYMBOL(default_mtd_writev);
272 EXPORT_SYMBOL(default_mtd_readv);
273
274 /*====================================================================*/
275 /* Power management code */
276
277 #ifdef CONFIG_PM
278
279 #include <linux/pm.h>
280
281 static struct pm_dev *mtd_pm_dev = NULL;
282
mtd_pm_callback(struct pm_dev * dev,pm_request_t rqst,void * data)283 static int mtd_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data)
284 {
285 int ret = 0, i;
286
287 if (down_trylock(&mtd_table_mutex))
288 return -EAGAIN;
289 if (rqst == PM_SUSPEND) {
290 for (i = 0; ret == 0 && i < MAX_MTD_DEVICES; i++) {
291 if (mtd_table[i] && mtd_table[i]->suspend)
292 ret = mtd_table[i]->suspend(mtd_table[i]);
293 }
294 } else i = MAX_MTD_DEVICES-1;
295
296 if (rqst == PM_RESUME || ret) {
297 for ( ; i >= 0; i--) {
298 if (mtd_table[i] && mtd_table[i]->resume)
299 mtd_table[i]->resume(mtd_table[i]);
300 }
301 }
302 up(&mtd_table_mutex);
303 return ret;
304 }
305 #endif
306
307 /*====================================================================*/
308 /* Support for /proc/mtd */
309
310 #ifdef CONFIG_PROC_FS
311
312 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
313 static struct proc_dir_entry *proc_mtd;
314 #endif
315
mtd_proc_info(char * buf,int i)316 static inline int mtd_proc_info (char *buf, int i)
317 {
318 struct mtd_info *this = mtd_table[i];
319
320 if (!this)
321 return 0;
322
323 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
324 this->erasesize, this->name);
325 }
326
mtd_read_proc(char * page,char ** start,off_t off,int count,int * eof,void * data_unused)327 static int mtd_read_proc ( char *page, char **start, off_t off,int count
328 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
329 ,int *eof, void *data_unused
330 #else
331 ,int unused
332 #endif
333 )
334 {
335 int len, l, i;
336 off_t begin = 0;
337
338 down(&mtd_table_mutex);
339
340 len = sprintf(page, "dev: size erasesize name\n");
341 for (i=0; i< MAX_MTD_DEVICES; i++) {
342
343 l = mtd_proc_info(page + len, i);
344 len += l;
345 if (len+begin > off+count)
346 goto done;
347 if (len+begin < off) {
348 begin += len;
349 len = 0;
350 }
351 }
352
353 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
354 *eof = 1;
355 #endif
356
357 done:
358 up(&mtd_table_mutex);
359 if (off >= len+begin)
360 return 0;
361 *start = page + (off-begin);
362 return ((count < begin+len-off) ? count : begin+len-off);
363 }
364
365 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,2,0)
366 struct proc_dir_entry mtd_proc_entry = {
367 0, /* low_ino: the inode -- dynamic */
368 3, "mtd", /* len of name and name */
369 S_IFREG | S_IRUGO, /* mode */
370 1, 0, 0, /* nlinks, owner, group */
371 0, NULL, /* size - unused; operations -- use default */
372 &mtd_read_proc, /* function used to read data */
373 /* nothing more */
374 };
375 #endif
376
377 #endif /* CONFIG_PROC_FS */
378
379 /*====================================================================*/
380 /* Init code */
381
init_mtd(void)382 int __init init_mtd(void)
383 {
384 #ifdef CONFIG_PROC_FS
385 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
386 if ((proc_mtd = create_proc_entry( "mtd", 0, 0 )))
387 proc_mtd->read_proc = mtd_read_proc;
388 #else
389 proc_register_dynamic(&proc_root,&mtd_proc_entry);
390 #endif
391 #endif
392
393 #if LINUX_VERSION_CODE < 0x20212
394 init_mtd_devices();
395 #endif
396
397 #ifdef CONFIG_PM
398 mtd_pm_dev = pm_register(PM_UNKNOWN_DEV, 0, mtd_pm_callback);
399 #endif
400 return 0;
401 }
402
cleanup_mtd(void)403 static void __exit cleanup_mtd(void)
404 {
405 #ifdef CONFIG_PM
406 if (mtd_pm_dev) {
407 pm_unregister(mtd_pm_dev);
408 mtd_pm_dev = NULL;
409 }
410 #endif
411
412 #ifdef CONFIG_PROC_FS
413 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
414 if (proc_mtd)
415 remove_proc_entry( "mtd", 0);
416 #else
417 proc_unregister(&proc_root,mtd_proc_entry.low_ino);
418 #endif
419 #endif
420 }
421
422 module_init(init_mtd);
423 module_exit(cleanup_mtd);
424
425
426 MODULE_LICENSE("GPL");
427 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
428 MODULE_DESCRIPTION("Core MTD registration and access routines");
429