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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Thomas Gleixner97894cd2005-11-07 11:15:26 +00002 * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Core registration and callback routines for MTD
5 * drivers and users.
6 *
7 */
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/module.h>
10#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/ptrace.h>
12#include <linux/slab.h>
13#include <linux/string.h>
14#include <linux/timer.h>
15#include <linux/major.h>
16#include <linux/fs.h>
Artem Bityutskiy77993082006-10-11 14:52:44 +030017#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/ioctl.h>
19#include <linux/init.h>
20#include <linux/mtd/compatmac.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <linux/mtd/mtd.h>
24
Thomas Gleixner97894cd2005-11-07 11:15:26 +000025/* These are exported solely for the purpose of mtd_blkdevs.c. You
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 should not use them for _anything_ else */
Ingo Molnar48b19262006-03-31 02:29:41 -080027DEFINE_MUTEX(mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070028struct mtd_info *mtd_table[MAX_MTD_DEVICES];
29
30EXPORT_SYMBOL_GPL(mtd_table_mutex);
31EXPORT_SYMBOL_GPL(mtd_table);
32
33static LIST_HEAD(mtd_notifiers);
34
35/**
36 * add_mtd_device - register an MTD device
37 * @mtd: pointer to new MTD device info structure
38 *
39 * Add a device to the list of MTD devices present in the system, and
40 * notify each currently active MTD 'user' of its arrival. Returns
41 * zero on success or 1 on failure, which currently will only happen
42 * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
43 */
44
45int add_mtd_device(struct mtd_info *mtd)
46{
47 int i;
48
Artem B. Bityutskiy783ed812006-06-14 19:53:44 +040049 BUG_ON(mtd->writesize == 0);
Ingo Molnar48b19262006-03-31 02:29:41 -080050 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52 for (i=0; i < MAX_MTD_DEVICES; i++)
53 if (!mtd_table[i]) {
54 struct list_head *this;
55
56 mtd_table[i] = mtd;
57 mtd->index = i;
58 mtd->usecount = 0;
59
HÃ¥vard Skinnemoen187ef152006-09-22 10:07:08 +010060 /* Some chips always power up locked. Unlock them now */
61 if ((mtd->flags & MTD_WRITEABLE)
62 && (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
63 if (mtd->unlock(mtd, 0, mtd->size))
64 printk(KERN_WARNING
65 "%s: unlock failed, "
66 "writes may not work\n",
67 mtd->name);
68 }
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
71 /* No need to get a refcount on the module containing
72 the notifier, since we hold the mtd_table_mutex */
73 list_for_each(this, &mtd_notifiers) {
74 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
75 not->add(mtd);
76 }
Thomas Gleixner97894cd2005-11-07 11:15:26 +000077
Ingo Molnar48b19262006-03-31 02:29:41 -080078 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 /* We _know_ we aren't being removed, because
80 our caller is still holding us here. So none
81 of this try_ nonsense, and no bitching about it
82 either. :) */
83 __module_get(THIS_MODULE);
84 return 0;
85 }
Thomas Gleixner97894cd2005-11-07 11:15:26 +000086
Ingo Molnar48b19262006-03-31 02:29:41 -080087 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return 1;
89}
90
91/**
92 * del_mtd_device - unregister an MTD device
93 * @mtd: pointer to MTD device info structure
94 *
95 * Remove a device from the list of MTD devices present in the system,
96 * and notify each currently active MTD 'user' of its departure.
97 * Returns zero on success or 1 on failure, which currently will happen
98 * if the requested device does not appear to be present in the list.
99 */
100
101int del_mtd_device (struct mtd_info *mtd)
102{
103 int ret;
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000104
Ingo Molnar48b19262006-03-31 02:29:41 -0800105 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107 if (mtd_table[mtd->index] != mtd) {
108 ret = -ENODEV;
109 } else if (mtd->usecount) {
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000110 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 mtd->index, mtd->name, mtd->usecount);
112 ret = -EBUSY;
113 } else {
114 struct list_head *this;
115
116 /* No need to get a refcount on the module containing
117 the notifier, since we hold the mtd_table_mutex */
118 list_for_each(this, &mtd_notifiers) {
119 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
120 not->remove(mtd);
121 }
122
123 mtd_table[mtd->index] = NULL;
124
125 module_put(THIS_MODULE);
126 ret = 0;
127 }
128
Ingo Molnar48b19262006-03-31 02:29:41 -0800129 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 return ret;
131}
132
133/**
134 * register_mtd_user - register a 'user' of MTD devices.
135 * @new: pointer to notifier info structure
136 *
137 * Registers a pair of callbacks function to be called upon addition
138 * or removal of MTD devices. Causes the 'add' callback to be immediately
139 * invoked for each MTD device currently present in the system.
140 */
141
142void register_mtd_user (struct mtd_notifier *new)
143{
144 int i;
145
Ingo Molnar48b19262006-03-31 02:29:41 -0800146 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
148 list_add(&new->list, &mtd_notifiers);
149
150 __module_get(THIS_MODULE);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 for (i=0; i< MAX_MTD_DEVICES; i++)
153 if (mtd_table[i])
154 new->add(mtd_table[i]);
155
Ingo Molnar48b19262006-03-31 02:29:41 -0800156 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158
159/**
Artem B. Bityuckiy49450792005-02-18 14:34:54 +0000160 * unregister_mtd_user - unregister a 'user' of MTD devices.
161 * @old: pointer to notifier info structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 *
163 * Removes a callback function pair from the list of 'users' to be
164 * notified upon addition or removal of MTD devices. Causes the
165 * 'remove' callback to be immediately invoked for each MTD device
166 * currently present in the system.
167 */
168
169int unregister_mtd_user (struct mtd_notifier *old)
170{
171 int i;
172
Ingo Molnar48b19262006-03-31 02:29:41 -0800173 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175 module_put(THIS_MODULE);
176
177 for (i=0; i< MAX_MTD_DEVICES; i++)
178 if (mtd_table[i])
179 old->remove(mtd_table[i]);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 list_del(&old->list);
Ingo Molnar48b19262006-03-31 02:29:41 -0800182 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 return 0;
184}
185
186
187/**
188 * get_mtd_device - obtain a validated handle for an MTD device
189 * @mtd: last known address of the required MTD device
190 * @num: internal device number of the required MTD device
191 *
192 * Given a number and NULL address, return the num'th entry in the device
193 * table, if any. Given an address and num == -1, search the device table
194 * for a device with that address and return if it's still present. Given
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300195 * both, return the num'th driver only if its address matches. Return
196 * error code if not.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 */
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
200{
201 struct mtd_info *ret = NULL;
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300202 int i, err = -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
Ingo Molnar48b19262006-03-31 02:29:41 -0800204 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 if (num == -1) {
207 for (i=0; i< MAX_MTD_DEVICES; i++)
208 if (mtd_table[i] == mtd)
209 ret = mtd_table[i];
210 } else if (num < MAX_MTD_DEVICES) {
211 ret = mtd_table[num];
212 if (mtd && mtd != ret)
213 ret = NULL;
214 }
215
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300216 if (!ret)
217 goto out_unlock;
218
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300219 if (!try_module_get(ret->owner))
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300220 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300222 if (ret->get_device) {
223 err = ret->get_device(ret);
224 if (err)
225 goto out_put;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300226 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300228 ret->usecount++;
Ingo Molnar48b19262006-03-31 02:29:41 -0800229 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 return ret;
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300231
232out_put:
233 module_put(ret->owner);
234out_unlock:
235 mutex_unlock(&mtd_table_mutex);
236 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237}
238
Artem Bityutskiy77993082006-10-11 14:52:44 +0300239/**
240 * get_mtd_device_nm - obtain a validated handle for an MTD device by
241 * device name
242 * @name: MTD device name to open
243 *
244 * This function returns MTD device description structure in case of
245 * success and an error code in case of failure.
246 */
247
248struct mtd_info *get_mtd_device_nm(const char *name)
249{
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300250 int i, err = -ENODEV;
251 struct mtd_info *mtd = NULL;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300252
253 mutex_lock(&mtd_table_mutex);
254
255 for (i = 0; i < MAX_MTD_DEVICES; i++) {
256 if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
257 mtd = mtd_table[i];
258 break;
259 }
260 }
261
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300262 if (!mtd)
Artem Bityutskiy77993082006-10-11 14:52:44 +0300263 goto out_unlock;
264
265 if (!try_module_get(mtd->owner))
266 goto out_unlock;
267
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300268 if (mtd->get_device) {
269 err = mtd->get_device(mtd);
270 if (err)
271 goto out_put;
272 }
Artem Bityutskiy77993082006-10-11 14:52:44 +0300273
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300274 mtd->usecount++;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300275 mutex_unlock(&mtd_table_mutex);
276 return mtd;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300277
278out_put:
279 module_put(mtd->owner);
280out_unlock:
281 mutex_unlock(&mtd_table_mutex);
282 return ERR_PTR(err);
Artem Bityutskiy77993082006-10-11 14:52:44 +0300283}
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285void put_mtd_device(struct mtd_info *mtd)
286{
287 int c;
288
Ingo Molnar48b19262006-03-31 02:29:41 -0800289 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 c = --mtd->usecount;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300291 if (mtd->put_device)
292 mtd->put_device(mtd);
Ingo Molnar48b19262006-03-31 02:29:41 -0800293 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 BUG_ON(c < 0);
295
296 module_put(mtd->owner);
297}
298
299/* default_mtd_writev - default mtd writev method for MTD devices that
David Woodhousedd36f262006-11-29 16:33:03 +0000300 * don't implement their own
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 */
302
303int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
304 unsigned long count, loff_t to, size_t *retlen)
305{
306 unsigned long i;
307 size_t totlen = 0, thislen;
308 int ret = 0;
309
310 if(!mtd->write) {
311 ret = -EROFS;
312 } else {
313 for (i=0; i<count; i++) {
314 if (!vecs[i].iov_len)
315 continue;
316 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
317 totlen += thislen;
318 if (ret || thislen != vecs[i].iov_len)
319 break;
320 to += vecs[i].iov_len;
321 }
322 }
323 if (retlen)
324 *retlen = totlen;
325 return ret;
326}
327
David Woodhousedd36f262006-11-29 16:33:03 +0000328EXPORT_SYMBOL_GPL(add_mtd_device);
329EXPORT_SYMBOL_GPL(del_mtd_device);
330EXPORT_SYMBOL_GPL(get_mtd_device);
331EXPORT_SYMBOL_GPL(get_mtd_device_nm);
332EXPORT_SYMBOL_GPL(put_mtd_device);
333EXPORT_SYMBOL_GPL(register_mtd_user);
334EXPORT_SYMBOL_GPL(unregister_mtd_user);
335EXPORT_SYMBOL_GPL(default_mtd_writev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Pavel Machek2d2dce02006-03-31 02:29:49 -0800337#ifdef CONFIG_PROC_FS
338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339/*====================================================================*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340/* Support for /proc/mtd */
341
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342static struct proc_dir_entry *proc_mtd;
343
344static inline int mtd_proc_info (char *buf, int i)
345{
346 struct mtd_info *this = mtd_table[i];
347
348 if (!this)
349 return 0;
350
351 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
352 this->erasesize, this->name);
353}
354
355static int mtd_read_proc (char *page, char **start, off_t off, int count,
356 int *eof, void *data_unused)
357{
358 int len, l, i;
359 off_t begin = 0;
360
Ingo Molnar48b19262006-03-31 02:29:41 -0800361 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 len = sprintf(page, "dev: size erasesize name\n");
364 for (i=0; i< MAX_MTD_DEVICES; i++) {
365
366 l = mtd_proc_info(page + len, i);
367 len += l;
368 if (len+begin > off+count)
369 goto done;
370 if (len+begin < off) {
371 begin += len;
372 len = 0;
373 }
374 }
375
376 *eof = 1;
377
378done:
Ingo Molnar48b19262006-03-31 02:29:41 -0800379 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 if (off >= len+begin)
381 return 0;
382 *start = page + (off-begin);
383 return ((count < begin+len-off) ? count : begin+len-off);
384}
385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386/*====================================================================*/
387/* Init code */
388
389static int __init init_mtd(void)
390{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
392 proc_mtd->read_proc = mtd_read_proc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 return 0;
394}
395
396static void __exit cleanup_mtd(void)
397{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 if (proc_mtd)
399 remove_proc_entry( "mtd", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
402module_init(init_mtd);
403module_exit(cleanup_mtd);
404
Pavel Machek2d2dce02006-03-31 02:29:49 -0800405#endif /* CONFIG_PROC_FS */
406
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408MODULE_LICENSE("GPL");
409MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
410MODULE_DESCRIPTION("Core MTD registration and access routines");