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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Artem B. Bityuckiy49450792005-02-18 14:34:54 +00002 * $Id: mtdcore.c,v 1.45 2005/02/18 14:34:50 dedekind Exp $
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Core registration and callback routines for MTD
5 * drivers and users.
6 *
7 */
8
9#include <linux/config.h>
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/ptrace.h>
14#include <linux/slab.h>
15#include <linux/string.h>
16#include <linux/timer.h>
17#include <linux/major.h>
18#include <linux/fs.h>
19#include <linux/ioctl.h>
20#include <linux/init.h>
21#include <linux/mtd/compatmac.h>
22#ifdef CONFIG_PROC_FS
23#include <linux/proc_fs.h>
24#endif
25
26#include <linux/mtd/mtd.h>
27
28/* These are exported solely for the purpose of mtd_blkdevs.c. You
29 should not use them for _anything_ else */
30DECLARE_MUTEX(mtd_table_mutex);
31struct mtd_info *mtd_table[MAX_MTD_DEVICES];
32
33EXPORT_SYMBOL_GPL(mtd_table_mutex);
34EXPORT_SYMBOL_GPL(mtd_table);
35
36static LIST_HEAD(mtd_notifiers);
37
38/**
39 * add_mtd_device - register an MTD device
40 * @mtd: pointer to new MTD device info structure
41 *
42 * Add a device to the list of MTD devices present in the system, and
43 * notify each currently active MTD 'user' of its arrival. Returns
44 * zero on success or 1 on failure, which currently will only happen
45 * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
46 */
47
48int add_mtd_device(struct mtd_info *mtd)
49{
50 int i;
51
52 down(&mtd_table_mutex);
53
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
62 DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
63 /* No need to get a refcount on the module containing
64 the notifier, since we hold the mtd_table_mutex */
65 list_for_each(this, &mtd_notifiers) {
66 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
67 not->add(mtd);
68 }
69
70 up(&mtd_table_mutex);
71 /* We _know_ we aren't being removed, because
72 our caller is still holding us here. So none
73 of this try_ nonsense, and no bitching about it
74 either. :) */
75 __module_get(THIS_MODULE);
76 return 0;
77 }
78
79 up(&mtd_table_mutex);
80 return 1;
81}
82
83/**
84 * del_mtd_device - unregister an MTD device
85 * @mtd: pointer to MTD device info structure
86 *
87 * Remove a device from the list of MTD devices present in the system,
88 * and notify each currently active MTD 'user' of its departure.
89 * Returns zero on success or 1 on failure, which currently will happen
90 * if the requested device does not appear to be present in the list.
91 */
92
93int del_mtd_device (struct mtd_info *mtd)
94{
95 int ret;
96
97 down(&mtd_table_mutex);
98
99 if (mtd_table[mtd->index] != mtd) {
100 ret = -ENODEV;
101 } else if (mtd->usecount) {
102 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
103 mtd->index, mtd->name, mtd->usecount);
104 ret = -EBUSY;
105 } else {
106 struct list_head *this;
107
108 /* No need to get a refcount on the module containing
109 the notifier, since we hold the mtd_table_mutex */
110 list_for_each(this, &mtd_notifiers) {
111 struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
112 not->remove(mtd);
113 }
114
115 mtd_table[mtd->index] = NULL;
116
117 module_put(THIS_MODULE);
118 ret = 0;
119 }
120
121 up(&mtd_table_mutex);
122 return ret;
123}
124
125/**
126 * register_mtd_user - register a 'user' of MTD devices.
127 * @new: pointer to notifier info structure
128 *
129 * Registers a pair of callbacks function to be called upon addition
130 * or removal of MTD devices. Causes the 'add' callback to be immediately
131 * invoked for each MTD device currently present in the system.
132 */
133
134void register_mtd_user (struct mtd_notifier *new)
135{
136 int i;
137
138 down(&mtd_table_mutex);
139
140 list_add(&new->list, &mtd_notifiers);
141
142 __module_get(THIS_MODULE);
143
144 for (i=0; i< MAX_MTD_DEVICES; i++)
145 if (mtd_table[i])
146 new->add(mtd_table[i]);
147
148 up(&mtd_table_mutex);
149}
150
151/**
Artem B. Bityuckiy49450792005-02-18 14:34:54 +0000152 * unregister_mtd_user - unregister a 'user' of MTD devices.
153 * @old: pointer to notifier info structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 *
155 * Removes a callback function pair from the list of 'users' to be
156 * notified upon addition or removal of MTD devices. Causes the
157 * 'remove' callback to be immediately invoked for each MTD device
158 * currently present in the system.
159 */
160
161int unregister_mtd_user (struct mtd_notifier *old)
162{
163 int i;
164
165 down(&mtd_table_mutex);
166
167 module_put(THIS_MODULE);
168
169 for (i=0; i< MAX_MTD_DEVICES; i++)
170 if (mtd_table[i])
171 old->remove(mtd_table[i]);
172
173 list_del(&old->list);
174 up(&mtd_table_mutex);
175 return 0;
176}
177
178
179/**
180 * get_mtd_device - obtain a validated handle for an MTD device
181 * @mtd: last known address of the required MTD device
182 * @num: internal device number of the required MTD device
183 *
184 * Given a number and NULL address, return the num'th entry in the device
185 * table, if any. Given an address and num == -1, search the device table
186 * for a device with that address and return if it's still present. Given
187 * both, return the num'th driver only if its address matches. Return NULL
188 * if not.
189 */
190
191struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
192{
193 struct mtd_info *ret = NULL;
194 int i;
195
196 down(&mtd_table_mutex);
197
198 if (num == -1) {
199 for (i=0; i< MAX_MTD_DEVICES; i++)
200 if (mtd_table[i] == mtd)
201 ret = mtd_table[i];
202 } else if (num < MAX_MTD_DEVICES) {
203 ret = mtd_table[num];
204 if (mtd && mtd != ret)
205 ret = NULL;
206 }
207
208 if (ret && !try_module_get(ret->owner))
209 ret = NULL;
210
211 if (ret)
212 ret->usecount++;
213
214 up(&mtd_table_mutex);
215 return ret;
216}
217
218void put_mtd_device(struct mtd_info *mtd)
219{
220 int c;
221
222 down(&mtd_table_mutex);
223 c = --mtd->usecount;
224 up(&mtd_table_mutex);
225 BUG_ON(c < 0);
226
227 module_put(mtd->owner);
228}
229
230/* default_mtd_writev - default mtd writev method for MTD devices that
231 * dont implement their own
232 */
233
234int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
235 unsigned long count, loff_t to, size_t *retlen)
236{
237 unsigned long i;
238 size_t totlen = 0, thislen;
239 int ret = 0;
240
241 if(!mtd->write) {
242 ret = -EROFS;
243 } else {
244 for (i=0; i<count; i++) {
245 if (!vecs[i].iov_len)
246 continue;
247 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
248 totlen += thislen;
249 if (ret || thislen != vecs[i].iov_len)
250 break;
251 to += vecs[i].iov_len;
252 }
253 }
254 if (retlen)
255 *retlen = totlen;
256 return ret;
257}
258
259
260/* default_mtd_readv - default mtd readv method for MTD devices that dont
261 * implement their own
262 */
263
264int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs,
265 unsigned long count, loff_t from, size_t *retlen)
266{
267 unsigned long i;
268 size_t totlen = 0, thislen;
269 int ret = 0;
270
271 if(!mtd->read) {
272 ret = -EIO;
273 } else {
274 for (i=0; i<count; i++) {
275 if (!vecs[i].iov_len)
276 continue;
277 ret = mtd->read(mtd, from, vecs[i].iov_len, &thislen, vecs[i].iov_base);
278 totlen += thislen;
279 if (ret || thislen != vecs[i].iov_len)
280 break;
281 from += vecs[i].iov_len;
282 }
283 }
284 if (retlen)
285 *retlen = totlen;
286 return ret;
287}
288
289
290EXPORT_SYMBOL(add_mtd_device);
291EXPORT_SYMBOL(del_mtd_device);
292EXPORT_SYMBOL(get_mtd_device);
293EXPORT_SYMBOL(put_mtd_device);
294EXPORT_SYMBOL(register_mtd_user);
295EXPORT_SYMBOL(unregister_mtd_user);
296EXPORT_SYMBOL(default_mtd_writev);
297EXPORT_SYMBOL(default_mtd_readv);
298
299/*====================================================================*/
300/* Power management code */
301
302#ifdef CONFIG_PM
303
304#include <linux/pm.h>
305
306static struct pm_dev *mtd_pm_dev = NULL;
307
308static int mtd_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data)
309{
310 int ret = 0, i;
311
312 if (down_trylock(&mtd_table_mutex))
313 return -EAGAIN;
314 if (rqst == PM_SUSPEND) {
315 for (i = 0; ret == 0 && i < MAX_MTD_DEVICES; i++) {
316 if (mtd_table[i] && mtd_table[i]->suspend)
317 ret = mtd_table[i]->suspend(mtd_table[i]);
318 }
319 } else i = MAX_MTD_DEVICES-1;
320
321 if (rqst == PM_RESUME || ret) {
322 for ( ; i >= 0; i--) {
323 if (mtd_table[i] && mtd_table[i]->resume)
324 mtd_table[i]->resume(mtd_table[i]);
325 }
326 }
327 up(&mtd_table_mutex);
328 return ret;
329}
330#endif
331
332/*====================================================================*/
333/* Support for /proc/mtd */
334
335#ifdef CONFIG_PROC_FS
336static struct proc_dir_entry *proc_mtd;
337
338static inline int mtd_proc_info (char *buf, int i)
339{
340 struct mtd_info *this = mtd_table[i];
341
342 if (!this)
343 return 0;
344
345 return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
346 this->erasesize, this->name);
347}
348
349static int mtd_read_proc (char *page, char **start, off_t off, int count,
350 int *eof, void *data_unused)
351{
352 int len, l, i;
353 off_t begin = 0;
354
355 down(&mtd_table_mutex);
356
357 len = sprintf(page, "dev: size erasesize name\n");
358 for (i=0; i< MAX_MTD_DEVICES; i++) {
359
360 l = mtd_proc_info(page + len, i);
361 len += l;
362 if (len+begin > off+count)
363 goto done;
364 if (len+begin < off) {
365 begin += len;
366 len = 0;
367 }
368 }
369
370 *eof = 1;
371
372done:
373 up(&mtd_table_mutex);
374 if (off >= len+begin)
375 return 0;
376 *start = page + (off-begin);
377 return ((count < begin+len-off) ? count : begin+len-off);
378}
379
380#endif /* CONFIG_PROC_FS */
381
382/*====================================================================*/
383/* Init code */
384
385static int __init init_mtd(void)
386{
387#ifdef CONFIG_PROC_FS
388 if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
389 proc_mtd->read_proc = mtd_read_proc;
390#endif
391
392#ifdef CONFIG_PM
393 mtd_pm_dev = pm_register(PM_UNKNOWN_DEV, 0, mtd_pm_callback);
394#endif
395 return 0;
396}
397
398static void __exit cleanup_mtd(void)
399{
400#ifdef CONFIG_PM
401 if (mtd_pm_dev) {
402 pm_unregister(mtd_pm_dev);
403 mtd_pm_dev = NULL;
404 }
405#endif
406
407#ifdef CONFIG_PROC_FS
408 if (proc_mtd)
409 remove_proc_entry( "mtd", NULL);
410#endif
411}
412
413module_init(init_mtd);
414module_exit(cleanup_mtd);
415
416
417MODULE_LICENSE("GPL");
418MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
419MODULE_DESCRIPTION("Core MTD registration and access routines");