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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>
11#include <linux/sched.h>
12#include <linux/ptrace.h>
13#include <linux/slab.h>
14#include <linux/string.h>
15#include <linux/timer.h>
16#include <linux/major.h>
17#include <linux/fs.h>
18#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
195 * both, return the num'th driver only if its address matches. Return NULL
196 * if not.
197 */
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;
202 int i;
203
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
216 if (ret && !try_module_get(ret->owner))
217 ret = NULL;
218
219 if (ret)
220 ret->usecount++;
221
Ingo Molnar48b19262006-03-31 02:29:41 -0800222 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 return ret;
224}
225
226void put_mtd_device(struct mtd_info *mtd)
227{
228 int c;
229
Ingo Molnar48b19262006-03-31 02:29:41 -0800230 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 c = --mtd->usecount;
Ingo Molnar48b19262006-03-31 02:29:41 -0800232 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 BUG_ON(c < 0);
234
235 module_put(mtd->owner);
236}
237
238/* default_mtd_writev - default mtd writev method for MTD devices that
239 * dont implement their own
240 */
241
242int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
243 unsigned long count, loff_t to, size_t *retlen)
244{
245 unsigned long i;
246 size_t totlen = 0, thislen;
247 int ret = 0;
248
249 if(!mtd->write) {
250 ret = -EROFS;
251 } else {
252 for (i=0; i<count; i++) {
253 if (!vecs[i].iov_len)
254 continue;
255 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
256 totlen += thislen;
257 if (ret || thislen != vecs[i].iov_len)
258 break;
259 to += vecs[i].iov_len;
260 }
261 }
262 if (retlen)
263 *retlen = totlen;
264 return ret;
265}
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267EXPORT_SYMBOL(add_mtd_device);
268EXPORT_SYMBOL(del_mtd_device);
269EXPORT_SYMBOL(get_mtd_device);
270EXPORT_SYMBOL(put_mtd_device);
271EXPORT_SYMBOL(register_mtd_user);
272EXPORT_SYMBOL(unregister_mtd_user);
273EXPORT_SYMBOL(default_mtd_writev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
Pavel Machek2d2dce02006-03-31 02:29:49 -0800275#ifdef CONFIG_PROC_FS
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277/*====================================================================*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278/* Support for /proc/mtd */
279
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280static struct proc_dir_entry *proc_mtd;
281
282static inline int mtd_proc_info (char *buf, int i)
283{
284 struct mtd_info *this = mtd_table[i];
285
286 if (!this)
287 return 0;
288
289 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
290 this->erasesize, this->name);
291}
292
293static int mtd_read_proc (char *page, char **start, off_t off, int count,
294 int *eof, void *data_unused)
295{
296 int len, l, i;
297 off_t begin = 0;
298
Ingo Molnar48b19262006-03-31 02:29:41 -0800299 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
301 len = sprintf(page, "dev: size erasesize name\n");
302 for (i=0; i< MAX_MTD_DEVICES; i++) {
303
304 l = mtd_proc_info(page + len, i);
305 len += l;
306 if (len+begin > off+count)
307 goto done;
308 if (len+begin < off) {
309 begin += len;
310 len = 0;
311 }
312 }
313
314 *eof = 1;
315
316done:
Ingo Molnar48b19262006-03-31 02:29:41 -0800317 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 if (off >= len+begin)
319 return 0;
320 *start = page + (off-begin);
321 return ((count < begin+len-off) ? count : begin+len-off);
322}
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324/*====================================================================*/
325/* Init code */
326
327static int __init init_mtd(void)
328{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
330 proc_mtd->read_proc = mtd_read_proc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 return 0;
332}
333
334static void __exit cleanup_mtd(void)
335{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 if (proc_mtd)
337 remove_proc_entry( "mtd", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338}
339
340module_init(init_mtd);
341module_exit(cleanup_mtd);
342
Pavel Machek2d2dce02006-03-31 02:29:49 -0800343#endif /* CONFIG_PROC_FS */
344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346MODULE_LICENSE("GPL");
347MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
348MODULE_DESCRIPTION("Core MTD registration and access routines");