2 * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
4 * Core registration and callback routines for MTD
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/ptrace.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/timer.h>
15 #include <linux/major.h>
17 #include <linux/err.h>
18 #include <linux/ioctl.h>
19 #include <linux/init.h>
20 #include <linux/mtd/compatmac.h>
21 #include <linux/proc_fs.h>
23 #include <linux/mtd/mtd.h>
27 /* These are exported solely for the purpose of mtd_blkdevs.c. You
28 should not use them for _anything_ else */
29 DEFINE_MUTEX(mtd_table_mutex);
30 struct mtd_info *mtd_table[MAX_MTD_DEVICES];
32 EXPORT_SYMBOL_GPL(mtd_table_mutex);
33 EXPORT_SYMBOL_GPL(mtd_table);
35 static LIST_HEAD(mtd_notifiers);
38 * add_mtd_device - register an MTD device
39 * @mtd: pointer to new MTD device info structure
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)
47 int add_mtd_device(struct mtd_info *mtd)
51 BUG_ON(mtd->writesize == 0);
52 mutex_lock(&mtd_table_mutex);
54 for (i=0; i < MAX_MTD_DEVICES; i++)
56 struct mtd_notifier *not;
62 /* Some chips always power up locked. Unlock them now */
63 if ((mtd->flags & MTD_WRITEABLE)
64 && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
65 if (mtd->unlock(mtd, 0, mtd->size))
68 "writes may not work\n",
72 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_entry(not, &mtd_notifiers, list) {
79 mutex_unlock(&mtd_table_mutex);
80 /* We _know_ we aren't being removed, because
81 our caller is still holding us here. So none
82 of this try_ nonsense, and no bitching about it
84 __module_get(THIS_MODULE);
88 mutex_unlock(&mtd_table_mutex);
93 * del_mtd_device - unregister an MTD device
94 * @mtd: pointer to MTD device info structure
96 * Remove a device from the list of MTD devices present in the system,
97 * and notify each currently active MTD 'user' of its departure.
98 * Returns zero on success or 1 on failure, which currently will happen
99 * if the requested device does not appear to be present in the list.
102 int del_mtd_device (struct mtd_info *mtd)
106 mutex_lock(&mtd_table_mutex);
108 if (mtd_table[mtd->index] != mtd) {
110 } else if (mtd->usecount) {
111 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
112 mtd->index, mtd->name, mtd->usecount);
115 struct mtd_notifier *not;
117 /* No need to get a refcount on the module containing
118 the notifier, since we hold the mtd_table_mutex */
119 list_for_each_entry(not, &mtd_notifiers, list) {
123 mtd_table[mtd->index] = NULL;
125 module_put(THIS_MODULE);
129 mutex_unlock(&mtd_table_mutex);
134 * register_mtd_user - register a 'user' of MTD devices.
135 * @new: pointer to notifier info structure
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.
142 void register_mtd_user (struct mtd_notifier *new)
146 mutex_lock(&mtd_table_mutex);
148 list_add(&new->list, &mtd_notifiers);
150 __module_get(THIS_MODULE);
152 for (i=0; i< MAX_MTD_DEVICES; i++)
154 new->add(mtd_table[i]);
156 mutex_unlock(&mtd_table_mutex);
160 * unregister_mtd_user - unregister a 'user' of MTD devices.
161 * @old: pointer to notifier info structure
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.
169 int unregister_mtd_user (struct mtd_notifier *old)
173 mutex_lock(&mtd_table_mutex);
175 module_put(THIS_MODULE);
177 for (i=0; i< MAX_MTD_DEVICES; i++)
179 old->remove(mtd_table[i]);
181 list_del(&old->list);
182 mutex_unlock(&mtd_table_mutex);
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
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
199 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
201 struct mtd_info *ret = NULL;
202 int i, err = -ENODEV;
204 mutex_lock(&mtd_table_mutex);
207 for (i=0; i< MAX_MTD_DEVICES; i++)
208 if (mtd_table[i] == mtd)
210 } else if (num < MAX_MTD_DEVICES) {
211 ret = mtd_table[num];
212 if (mtd && mtd != ret)
219 if (!try_module_get(ret->owner))
222 if (ret->get_device) {
223 err = ret->get_device(ret);
229 mutex_unlock(&mtd_table_mutex);
233 module_put(ret->owner);
235 mutex_unlock(&mtd_table_mutex);
240 * get_mtd_device_nm - obtain a validated handle for an MTD device by
242 * @name: MTD device name to open
244 * This function returns MTD device description structure in case of
245 * success and an error code in case of failure.
248 struct mtd_info *get_mtd_device_nm(const char *name)
250 int i, err = -ENODEV;
251 struct mtd_info *mtd = NULL;
253 mutex_lock(&mtd_table_mutex);
255 for (i = 0; i < MAX_MTD_DEVICES; i++) {
256 if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
265 if (!try_module_get(mtd->owner))
268 if (mtd->get_device) {
269 err = mtd->get_device(mtd);
275 mutex_unlock(&mtd_table_mutex);
279 module_put(mtd->owner);
281 mutex_unlock(&mtd_table_mutex);
285 void put_mtd_device(struct mtd_info *mtd)
289 mutex_lock(&mtd_table_mutex);
292 mtd->put_device(mtd);
293 mutex_unlock(&mtd_table_mutex);
296 module_put(mtd->owner);
299 /* default_mtd_writev - default mtd writev method for MTD devices that
300 * don't implement their own
303 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
304 unsigned long count, loff_t to, size_t *retlen)
307 size_t totlen = 0, thislen;
313 for (i=0; i<count; i++) {
314 if (!vecs[i].iov_len)
316 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
318 if (ret || thislen != vecs[i].iov_len)
320 to += vecs[i].iov_len;
328 EXPORT_SYMBOL_GPL(add_mtd_device);
329 EXPORT_SYMBOL_GPL(del_mtd_device);
330 EXPORT_SYMBOL_GPL(get_mtd_device);
331 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
332 EXPORT_SYMBOL_GPL(put_mtd_device);
333 EXPORT_SYMBOL_GPL(register_mtd_user);
334 EXPORT_SYMBOL_GPL(unregister_mtd_user);
335 EXPORT_SYMBOL_GPL(default_mtd_writev);
337 #ifdef CONFIG_PROC_FS
339 /*====================================================================*/
340 /* Support for /proc/mtd */
342 static struct proc_dir_entry *proc_mtd;
344 static inline int mtd_proc_info (char *buf, int i)
346 struct mtd_info *this = mtd_table[i];
351 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
352 this->erasesize, this->name);
355 static int mtd_read_proc (char *page, char **start, off_t off, int count,
356 int *eof, void *data_unused)
361 mutex_lock(&mtd_table_mutex);
363 len = sprintf(page, "dev: size erasesize name\n");
364 for (i=0; i< MAX_MTD_DEVICES; i++) {
366 l = mtd_proc_info(page + len, i);
368 if (len+begin > off+count)
370 if (len+begin < off) {
379 mutex_unlock(&mtd_table_mutex);
380 if (off >= len+begin)
382 *start = page + (off-begin);
383 return ((count < begin+len-off) ? count : begin+len-off);
386 /*====================================================================*/
389 static int __init init_mtd(void)
391 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
392 proc_mtd->read_proc = mtd_read_proc;
396 static void __exit cleanup_mtd(void)
399 remove_proc_entry( "mtd", NULL);
402 module_init(init_mtd);
403 module_exit(cleanup_mtd);
405 #endif /* CONFIG_PROC_FS */
408 MODULE_LICENSE("GPL");
409 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
410 MODULE_DESCRIPTION("Core MTD registration and access routines");