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/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>
18 #include <linux/err.h>
19 #include <linux/ioctl.h>
20 #include <linux/init.h>
21 #include <linux/mtd/compatmac.h>
22 #include <linux/proc_fs.h>
24 #include <linux/mtd/mtd.h>
26 /* These are exported solely for the purpose of mtd_blkdevs.c. You
27 should not use them for _anything_ else */
28 DEFINE_MUTEX(mtd_table_mutex);
29 struct mtd_info *mtd_table[MAX_MTD_DEVICES];
31 EXPORT_SYMBOL_GPL(mtd_table_mutex);
32 EXPORT_SYMBOL_GPL(mtd_table);
34 static LIST_HEAD(mtd_notifiers);
37 * add_mtd_device - register an MTD device
38 * @mtd: pointer to new MTD device info structure
40 * Add a device to the list of MTD devices present in the system, and
41 * notify each currently active MTD 'user' of its arrival. Returns
42 * zero on success or 1 on failure, which currently will only happen
43 * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
46 int add_mtd_device(struct mtd_info *mtd)
50 BUG_ON(mtd->writesize == 0);
51 mutex_lock(&mtd_table_mutex);
53 for (i=0; i < MAX_MTD_DEVICES; i++)
55 struct list_head *this;
61 /* Some chips always power up locked. Unlock them now */
62 if ((mtd->flags & MTD_WRITEABLE)
63 && (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
64 if (mtd->unlock(mtd, 0, mtd->size))
67 "writes may not work\n",
71 DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
72 /* No need to get a refcount on the module containing
73 the notifier, since we hold the mtd_table_mutex */
74 list_for_each(this, &mtd_notifiers) {
75 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, 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 list_head *this;
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(this, &mtd_notifiers) {
120 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
124 mtd_table[mtd->index] = NULL;
126 module_put(THIS_MODULE);
130 mutex_unlock(&mtd_table_mutex);
135 * register_mtd_user - register a 'user' of MTD devices.
136 * @new: pointer to notifier info structure
138 * Registers a pair of callbacks function to be called upon addition
139 * or removal of MTD devices. Causes the 'add' callback to be immediately
140 * invoked for each MTD device currently present in the system.
143 void register_mtd_user (struct mtd_notifier *new)
147 mutex_lock(&mtd_table_mutex);
149 list_add(&new->list, &mtd_notifiers);
151 __module_get(THIS_MODULE);
153 for (i=0; i< MAX_MTD_DEVICES; i++)
155 new->add(mtd_table[i]);
157 mutex_unlock(&mtd_table_mutex);
161 * unregister_mtd_user - unregister a 'user' of MTD devices.
162 * @old: pointer to notifier info structure
164 * Removes a callback function pair from the list of 'users' to be
165 * notified upon addition or removal of MTD devices. Causes the
166 * 'remove' callback to be immediately invoked for each MTD device
167 * currently present in the system.
170 int unregister_mtd_user (struct mtd_notifier *old)
174 mutex_lock(&mtd_table_mutex);
176 module_put(THIS_MODULE);
178 for (i=0; i< MAX_MTD_DEVICES; i++)
180 old->remove(mtd_table[i]);
182 list_del(&old->list);
183 mutex_unlock(&mtd_table_mutex);
189 * get_mtd_device - obtain a validated handle for an MTD device
190 * @mtd: last known address of the required MTD device
191 * @num: internal device number of the required MTD device
193 * Given a number and NULL address, return the num'th entry in the device
194 * table, if any. Given an address and num == -1, search the device table
195 * for a device with that address and return if it's still present. Given
196 * both, return the num'th driver only if its address matches. Return NULL
200 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
202 struct mtd_info *ret = NULL;
205 mutex_lock(&mtd_table_mutex);
208 for (i=0; i< MAX_MTD_DEVICES; i++)
209 if (mtd_table[i] == mtd)
211 } else if (num < MAX_MTD_DEVICES) {
212 ret = mtd_table[num];
213 if (mtd && mtd != ret)
217 if (ret && !try_module_get(ret->owner))
223 mutex_unlock(&mtd_table_mutex);
228 * get_mtd_device_nm - obtain a validated handle for an MTD device by
230 * @name: MTD device name to open
232 * This function returns MTD device description structure in case of
233 * success and an error code in case of failure.
236 struct mtd_info *get_mtd_device_nm(const char *name)
239 struct mtd_info *mtd = ERR_PTR(-ENODEV);
241 mutex_lock(&mtd_table_mutex);
243 for (i = 0; i < MAX_MTD_DEVICES; i++) {
244 if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
250 if (i == MAX_MTD_DEVICES)
253 if (!try_module_get(mtd->owner))
259 mutex_unlock(&mtd_table_mutex);
263 void put_mtd_device(struct mtd_info *mtd)
267 mutex_lock(&mtd_table_mutex);
269 mutex_unlock(&mtd_table_mutex);
272 module_put(mtd->owner);
275 /* default_mtd_writev - default mtd writev method for MTD devices that
276 * dont implement their own
279 int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
280 unsigned long count, loff_t to, size_t *retlen)
283 size_t totlen = 0, thislen;
289 for (i=0; i<count; i++) {
290 if (!vecs[i].iov_len)
292 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
294 if (ret || thislen != vecs[i].iov_len)
296 to += vecs[i].iov_len;
304 EXPORT_SYMBOL(add_mtd_device);
305 EXPORT_SYMBOL(del_mtd_device);
306 EXPORT_SYMBOL(get_mtd_device);
307 EXPORT_SYMBOL(get_mtd_device_nm);
308 EXPORT_SYMBOL(put_mtd_device);
309 EXPORT_SYMBOL(register_mtd_user);
310 EXPORT_SYMBOL(unregister_mtd_user);
311 EXPORT_SYMBOL(default_mtd_writev);
313 #ifdef CONFIG_PROC_FS
315 /*====================================================================*/
316 /* Support for /proc/mtd */
318 static struct proc_dir_entry *proc_mtd;
320 static inline int mtd_proc_info (char *buf, int i)
322 struct mtd_info *this = mtd_table[i];
327 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
328 this->erasesize, this->name);
331 static int mtd_read_proc (char *page, char **start, off_t off, int count,
332 int *eof, void *data_unused)
337 mutex_lock(&mtd_table_mutex);
339 len = sprintf(page, "dev: size erasesize name\n");
340 for (i=0; i< MAX_MTD_DEVICES; i++) {
342 l = mtd_proc_info(page + len, i);
344 if (len+begin > off+count)
346 if (len+begin < off) {
355 mutex_unlock(&mtd_table_mutex);
356 if (off >= len+begin)
358 *start = page + (off-begin);
359 return ((count < begin+len-off) ? count : begin+len-off);
362 /*====================================================================*/
365 static int __init init_mtd(void)
367 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
368 proc_mtd->read_proc = mtd_read_proc;
372 static void __exit cleanup_mtd(void)
375 remove_proc_entry( "mtd", NULL);
378 module_init(init_mtd);
379 module_exit(cleanup_mtd);
381 #endif /* CONFIG_PROC_FS */
384 MODULE_LICENSE("GPL");
385 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
386 MODULE_DESCRIPTION("Core MTD registration and access routines");