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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
Ben Dooks356d70f2007-05-28 20:28:34 +010025#include "mtdcore.h"
26
Thomas Gleixner97894cd2005-11-07 11:15:26 +000027/* These are exported solely for the purpose of mtd_blkdevs.c. You
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 should not use them for _anything_ else */
Ingo Molnar48b19262006-03-31 02:29:41 -080029DEFINE_MUTEX(mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070030struct mtd_info *mtd_table[MAX_MTD_DEVICES];
31
32EXPORT_SYMBOL_GPL(mtd_table_mutex);
33EXPORT_SYMBOL_GPL(mtd_table);
34
35static LIST_HEAD(mtd_notifiers);
36
37/**
38 * add_mtd_device - register an MTD device
39 * @mtd: pointer to new MTD device info structure
40 *
41 * Add a device to the list of MTD devices present in the system, and
42 * notify each currently active MTD 'user' of its arrival. Returns
43 * zero on success or 1 on failure, which currently will only happen
44 * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
45 */
46
47int add_mtd_device(struct mtd_info *mtd)
48{
49 int i;
50
Artem B. Bityutskiy783ed812006-06-14 19:53:44 +040051 BUG_ON(mtd->writesize == 0);
Ingo Molnar48b19262006-03-31 02:29:41 -080052 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 for (i=0; i < MAX_MTD_DEVICES; i++)
55 if (!mtd_table[i]) {
56 struct list_head *this;
57
58 mtd_table[i] = mtd;
59 mtd->index = i;
60 mtd->usecount = 0;
61
Håvard Skinnemoen187ef152006-09-22 10:07:08 +010062 /* Some chips always power up locked. Unlock them now */
63 if ((mtd->flags & MTD_WRITEABLE)
Justin Treone619a752008-01-30 10:25:49 -080064 && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
Håvard Skinnemoen187ef152006-09-22 10:07:08 +010065 if (mtd->unlock(mtd, 0, mtd->size))
66 printk(KERN_WARNING
67 "%s: unlock failed, "
68 "writes may not work\n",
69 mtd->name);
70 }
71
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
73 /* No need to get a refcount on the module containing
74 the notifier, since we hold the mtd_table_mutex */
75 list_for_each(this, &mtd_notifiers) {
76 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
77 not->add(mtd);
78 }
Thomas Gleixner97894cd2005-11-07 11:15:26 +000079
Ingo Molnar48b19262006-03-31 02:29:41 -080080 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 /* We _know_ we aren't being removed, because
82 our caller is still holding us here. So none
83 of this try_ nonsense, and no bitching about it
84 either. :) */
85 __module_get(THIS_MODULE);
86 return 0;
87 }
Thomas Gleixner97894cd2005-11-07 11:15:26 +000088
Ingo Molnar48b19262006-03-31 02:29:41 -080089 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 return 1;
91}
92
93/**
94 * del_mtd_device - unregister an MTD device
95 * @mtd: pointer to MTD device info structure
96 *
97 * Remove a device from the list of MTD devices present in the system,
98 * and notify each currently active MTD 'user' of its departure.
99 * Returns zero on success or 1 on failure, which currently will happen
100 * if the requested device does not appear to be present in the list.
101 */
102
103int del_mtd_device (struct mtd_info *mtd)
104{
105 int ret;
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000106
Ingo Molnar48b19262006-03-31 02:29:41 -0800107 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109 if (mtd_table[mtd->index] != mtd) {
110 ret = -ENODEV;
111 } else if (mtd->usecount) {
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000112 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 mtd->index, mtd->name, mtd->usecount);
114 ret = -EBUSY;
115 } else {
116 struct list_head *this;
117
118 /* No need to get a refcount on the module containing
119 the notifier, since we hold the mtd_table_mutex */
120 list_for_each(this, &mtd_notifiers) {
121 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
122 not->remove(mtd);
123 }
124
125 mtd_table[mtd->index] = NULL;
126
127 module_put(THIS_MODULE);
128 ret = 0;
129 }
130
Ingo Molnar48b19262006-03-31 02:29:41 -0800131 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 return ret;
133}
134
135/**
136 * register_mtd_user - register a 'user' of MTD devices.
137 * @new: pointer to notifier info structure
138 *
139 * Registers a pair of callbacks function to be called upon addition
140 * or removal of MTD devices. Causes the 'add' callback to be immediately
141 * invoked for each MTD device currently present in the system.
142 */
143
144void register_mtd_user (struct mtd_notifier *new)
145{
146 int i;
147
Ingo Molnar48b19262006-03-31 02:29:41 -0800148 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150 list_add(&new->list, &mtd_notifiers);
151
152 __module_get(THIS_MODULE);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000153
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 for (i=0; i< MAX_MTD_DEVICES; i++)
155 if (mtd_table[i])
156 new->add(mtd_table[i]);
157
Ingo Molnar48b19262006-03-31 02:29:41 -0800158 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
161/**
Artem B. Bityuckiy49450792005-02-18 14:34:54 +0000162 * unregister_mtd_user - unregister a 'user' of MTD devices.
163 * @old: pointer to notifier info structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 *
165 * Removes a callback function pair from the list of 'users' to be
166 * notified upon addition or removal of MTD devices. Causes the
167 * 'remove' callback to be immediately invoked for each MTD device
168 * currently present in the system.
169 */
170
171int unregister_mtd_user (struct mtd_notifier *old)
172{
173 int i;
174
Ingo Molnar48b19262006-03-31 02:29:41 -0800175 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
177 module_put(THIS_MODULE);
178
179 for (i=0; i< MAX_MTD_DEVICES; i++)
180 if (mtd_table[i])
181 old->remove(mtd_table[i]);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 list_del(&old->list);
Ingo Molnar48b19262006-03-31 02:29:41 -0800184 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 return 0;
186}
187
188
189/**
190 * get_mtd_device - obtain a validated handle for an MTD device
191 * @mtd: last known address of the required MTD device
192 * @num: internal device number of the required MTD device
193 *
194 * Given a number and NULL address, return the num'th entry in the device
195 * table, if any. Given an address and num == -1, search the device table
196 * for a device with that address and return if it's still present. Given
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300197 * both, return the num'th driver only if its address matches. Return
198 * error code if not.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 */
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
202{
203 struct mtd_info *ret = NULL;
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300204 int i, err = -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Ingo Molnar48b19262006-03-31 02:29:41 -0800206 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208 if (num == -1) {
209 for (i=0; i< MAX_MTD_DEVICES; i++)
210 if (mtd_table[i] == mtd)
211 ret = mtd_table[i];
212 } else if (num < MAX_MTD_DEVICES) {
213 ret = mtd_table[num];
214 if (mtd && mtd != ret)
215 ret = NULL;
216 }
217
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300218 if (!ret)
219 goto out_unlock;
220
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300221 if (!try_module_get(ret->owner))
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300222 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300224 if (ret->get_device) {
225 err = ret->get_device(ret);
226 if (err)
227 goto out_put;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300228 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300230 ret->usecount++;
Ingo Molnar48b19262006-03-31 02:29:41 -0800231 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 return ret;
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300233
234out_put:
235 module_put(ret->owner);
236out_unlock:
237 mutex_unlock(&mtd_table_mutex);
238 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
Artem Bityutskiy77993082006-10-11 14:52:44 +0300241/**
242 * get_mtd_device_nm - obtain a validated handle for an MTD device by
243 * device name
244 * @name: MTD device name to open
245 *
246 * This function returns MTD device description structure in case of
247 * success and an error code in case of failure.
248 */
249
250struct mtd_info *get_mtd_device_nm(const char *name)
251{
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300252 int i, err = -ENODEV;
253 struct mtd_info *mtd = NULL;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300254
255 mutex_lock(&mtd_table_mutex);
256
257 for (i = 0; i < MAX_MTD_DEVICES; i++) {
258 if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
259 mtd = mtd_table[i];
260 break;
261 }
262 }
263
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300264 if (!mtd)
Artem Bityutskiy77993082006-10-11 14:52:44 +0300265 goto out_unlock;
266
267 if (!try_module_get(mtd->owner))
268 goto out_unlock;
269
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300270 if (mtd->get_device) {
271 err = mtd->get_device(mtd);
272 if (err)
273 goto out_put;
274 }
Artem Bityutskiy77993082006-10-11 14:52:44 +0300275
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300276 mtd->usecount++;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300277 mutex_unlock(&mtd_table_mutex);
278 return mtd;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300279
280out_put:
281 module_put(mtd->owner);
282out_unlock:
283 mutex_unlock(&mtd_table_mutex);
284 return ERR_PTR(err);
Artem Bityutskiy77993082006-10-11 14:52:44 +0300285}
286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287void put_mtd_device(struct mtd_info *mtd)
288{
289 int c;
290
Ingo Molnar48b19262006-03-31 02:29:41 -0800291 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 c = --mtd->usecount;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300293 if (mtd->put_device)
294 mtd->put_device(mtd);
Ingo Molnar48b19262006-03-31 02:29:41 -0800295 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 BUG_ON(c < 0);
297
298 module_put(mtd->owner);
299}
300
301/* default_mtd_writev - default mtd writev method for MTD devices that
David Woodhousedd36f262006-11-29 16:33:03 +0000302 * don't implement their own
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 */
304
305int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
306 unsigned long count, loff_t to, size_t *retlen)
307{
308 unsigned long i;
309 size_t totlen = 0, thislen;
310 int ret = 0;
311
312 if(!mtd->write) {
313 ret = -EROFS;
314 } else {
315 for (i=0; i<count; i++) {
316 if (!vecs[i].iov_len)
317 continue;
318 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
319 totlen += thislen;
320 if (ret || thislen != vecs[i].iov_len)
321 break;
322 to += vecs[i].iov_len;
323 }
324 }
325 if (retlen)
326 *retlen = totlen;
327 return ret;
328}
329
David Woodhousedd36f262006-11-29 16:33:03 +0000330EXPORT_SYMBOL_GPL(add_mtd_device);
331EXPORT_SYMBOL_GPL(del_mtd_device);
332EXPORT_SYMBOL_GPL(get_mtd_device);
333EXPORT_SYMBOL_GPL(get_mtd_device_nm);
334EXPORT_SYMBOL_GPL(put_mtd_device);
335EXPORT_SYMBOL_GPL(register_mtd_user);
336EXPORT_SYMBOL_GPL(unregister_mtd_user);
337EXPORT_SYMBOL_GPL(default_mtd_writev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Pavel Machek2d2dce02006-03-31 02:29:49 -0800339#ifdef CONFIG_PROC_FS
340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341/*====================================================================*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342/* Support for /proc/mtd */
343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344static struct proc_dir_entry *proc_mtd;
345
346static inline int mtd_proc_info (char *buf, int i)
347{
348 struct mtd_info *this = mtd_table[i];
349
350 if (!this)
351 return 0;
352
353 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
354 this->erasesize, this->name);
355}
356
357static int mtd_read_proc (char *page, char **start, off_t off, int count,
358 int *eof, void *data_unused)
359{
360 int len, l, i;
361 off_t begin = 0;
362
Ingo Molnar48b19262006-03-31 02:29:41 -0800363 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
365 len = sprintf(page, "dev: size erasesize name\n");
366 for (i=0; i< MAX_MTD_DEVICES; i++) {
367
368 l = mtd_proc_info(page + len, i);
369 len += l;
370 if (len+begin > off+count)
371 goto done;
372 if (len+begin < off) {
373 begin += len;
374 len = 0;
375 }
376 }
377
378 *eof = 1;
379
380done:
Ingo Molnar48b19262006-03-31 02:29:41 -0800381 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 if (off >= len+begin)
383 return 0;
384 *start = page + (off-begin);
385 return ((count < begin+len-off) ? count : begin+len-off);
386}
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388/*====================================================================*/
389/* Init code */
390
391static int __init init_mtd(void)
392{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
394 proc_mtd->read_proc = mtd_read_proc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 return 0;
396}
397
398static void __exit cleanup_mtd(void)
399{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 if (proc_mtd)
401 remove_proc_entry( "mtd", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402}
403
404module_init(init_mtd);
405module_exit(cleanup_mtd);
406
Pavel Machek2d2dce02006-03-31 02:29:49 -0800407#endif /* CONFIG_PROC_FS */
408
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410MODULE_LICENSE("GPL");
411MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
412MODULE_DESCRIPTION("Core MTD registration and access routines");