Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 2 | * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Core registration and callback routines for MTD |
| 5 | * drivers and users. |
| 6 | * |
| 7 | */ |
| 8 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
| 17 | #include <linux/fs.h> |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 18 | #include <linux/err.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/ioctl.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/mtd/compatmac.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/proc_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | #include <linux/mtd/mtd.h> |
| 25 | |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 26 | /* These are exported solely for the purpose of mtd_blkdevs.c. You |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | should not use them for _anything_ else */ |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 28 | DEFINE_MUTEX(mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | struct mtd_info *mtd_table[MAX_MTD_DEVICES]; |
| 30 | |
| 31 | EXPORT_SYMBOL_GPL(mtd_table_mutex); |
| 32 | EXPORT_SYMBOL_GPL(mtd_table); |
| 33 | |
| 34 | static LIST_HEAD(mtd_notifiers); |
| 35 | |
| 36 | /** |
| 37 | * add_mtd_device - register an MTD device |
| 38 | * @mtd: pointer to new MTD device info structure |
| 39 | * |
| 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) |
| 44 | */ |
| 45 | |
| 46 | int add_mtd_device(struct mtd_info *mtd) |
| 47 | { |
| 48 | int i; |
| 49 | |
Artem B. Bityutskiy | 783ed81 | 2006-06-14 19:53:44 +0400 | [diff] [blame] | 50 | BUG_ON(mtd->writesize == 0); |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 51 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
| 53 | for (i=0; i < MAX_MTD_DEVICES; i++) |
| 54 | if (!mtd_table[i]) { |
| 55 | struct list_head *this; |
| 56 | |
| 57 | mtd_table[i] = mtd; |
| 58 | mtd->index = i; |
| 59 | mtd->usecount = 0; |
| 60 | |
HÃ¥vard Skinnemoen | 187ef15 | 2006-09-22 10:07:08 +0100 | [diff] [blame] | 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)) |
| 65 | printk(KERN_WARNING |
| 66 | "%s: unlock failed, " |
| 67 | "writes may not work\n", |
| 68 | mtd->name); |
| 69 | } |
| 70 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |
| 76 | not->add(mtd); |
| 77 | } |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 78 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 79 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
| 83 | either. :) */ |
| 84 | __module_get(THIS_MODULE); |
| 85 | return 0; |
| 86 | } |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 87 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 88 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | return 1; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * del_mtd_device - unregister an MTD device |
| 94 | * @mtd: pointer to MTD device info structure |
| 95 | * |
| 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. |
| 100 | */ |
| 101 | |
| 102 | int del_mtd_device (struct mtd_info *mtd) |
| 103 | { |
| 104 | int ret; |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 105 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 106 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | |
| 108 | if (mtd_table[mtd->index] != mtd) { |
| 109 | ret = -ENODEV; |
| 110 | } else if (mtd->usecount) { |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 111 | printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | mtd->index, mtd->name, mtd->usecount); |
| 113 | ret = -EBUSY; |
| 114 | } else { |
| 115 | struct list_head *this; |
| 116 | |
| 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); |
| 121 | not->remove(mtd); |
| 122 | } |
| 123 | |
| 124 | mtd_table[mtd->index] = NULL; |
| 125 | |
| 126 | module_put(THIS_MODULE); |
| 127 | ret = 0; |
| 128 | } |
| 129 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 130 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * register_mtd_user - register a 'user' of MTD devices. |
| 136 | * @new: pointer to notifier info structure |
| 137 | * |
| 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. |
| 141 | */ |
| 142 | |
| 143 | void register_mtd_user (struct mtd_notifier *new) |
| 144 | { |
| 145 | int i; |
| 146 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 147 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
| 149 | list_add(&new->list, &mtd_notifiers); |
| 150 | |
| 151 | __module_get(THIS_MODULE); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 152 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | for (i=0; i< MAX_MTD_DEVICES; i++) |
| 154 | if (mtd_table[i]) |
| 155 | new->add(mtd_table[i]); |
| 156 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 157 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | /** |
Artem B. Bityuckiy | 4945079 | 2005-02-18 14:34:54 +0000 | [diff] [blame] | 161 | * unregister_mtd_user - unregister a 'user' of MTD devices. |
| 162 | * @old: pointer to notifier info structure |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | * |
| 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. |
| 168 | */ |
| 169 | |
| 170 | int unregister_mtd_user (struct mtd_notifier *old) |
| 171 | { |
| 172 | int i; |
| 173 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 174 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | |
| 176 | module_put(THIS_MODULE); |
| 177 | |
| 178 | for (i=0; i< MAX_MTD_DEVICES; i++) |
| 179 | if (mtd_table[i]) |
| 180 | old->remove(mtd_table[i]); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | list_del(&old->list); |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 183 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | |
| 188 | /** |
| 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 |
| 192 | * |
| 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 |
Artem Bityutskiy | 9c74034 | 2006-10-11 14:52:47 +0300 | [diff] [blame^] | 196 | * both, return the num'th driver only if its address matches. Return |
| 197 | * error code if not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | */ |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) |
| 201 | { |
| 202 | struct mtd_info *ret = NULL; |
Artem Bityutskiy | 9c74034 | 2006-10-11 14:52:47 +0300 | [diff] [blame^] | 203 | int i, err = -ENODEV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 205 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | |
| 207 | if (num == -1) { |
| 208 | for (i=0; i< MAX_MTD_DEVICES; i++) |
| 209 | if (mtd_table[i] == mtd) |
| 210 | ret = mtd_table[i]; |
| 211 | } else if (num < MAX_MTD_DEVICES) { |
| 212 | ret = mtd_table[num]; |
| 213 | if (mtd && mtd != ret) |
| 214 | ret = NULL; |
| 215 | } |
| 216 | |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 217 | if (!ret) |
| 218 | goto out_unlock; |
| 219 | |
Artem Bityutskiy | 9c74034 | 2006-10-11 14:52:47 +0300 | [diff] [blame^] | 220 | if (!try_module_get(ret->owner)) |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 221 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | |
Artem Bityutskiy | 9c74034 | 2006-10-11 14:52:47 +0300 | [diff] [blame^] | 223 | if (ret->get_device) { |
| 224 | err = ret->get_device(ret); |
| 225 | if (err) |
| 226 | goto out_put; |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 227 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 229 | ret->usecount++; |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 230 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | return ret; |
Artem Bityutskiy | 9c74034 | 2006-10-11 14:52:47 +0300 | [diff] [blame^] | 232 | |
| 233 | out_put: |
| 234 | module_put(ret->owner); |
| 235 | out_unlock: |
| 236 | mutex_unlock(&mtd_table_mutex); |
| 237 | return ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 240 | /** |
| 241 | * get_mtd_device_nm - obtain a validated handle for an MTD device by |
| 242 | * device name |
| 243 | * @name: MTD device name to open |
| 244 | * |
| 245 | * This function returns MTD device description structure in case of |
| 246 | * success and an error code in case of failure. |
| 247 | */ |
| 248 | |
| 249 | struct mtd_info *get_mtd_device_nm(const char *name) |
| 250 | { |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 251 | int i, err = -ENODEV; |
| 252 | struct mtd_info *mtd = NULL; |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 253 | |
| 254 | mutex_lock(&mtd_table_mutex); |
| 255 | |
| 256 | for (i = 0; i < MAX_MTD_DEVICES; i++) { |
| 257 | if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) { |
| 258 | mtd = mtd_table[i]; |
| 259 | break; |
| 260 | } |
| 261 | } |
| 262 | |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 263 | if (!mtd) |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 264 | goto out_unlock; |
| 265 | |
| 266 | if (!try_module_get(mtd->owner)) |
| 267 | goto out_unlock; |
| 268 | |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 269 | if (mtd->get_device) { |
| 270 | err = mtd->get_device(mtd); |
| 271 | if (err) |
| 272 | goto out_put; |
| 273 | } |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 274 | |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 275 | mtd->usecount++; |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 276 | mutex_unlock(&mtd_table_mutex); |
| 277 | return mtd; |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 278 | |
| 279 | out_put: |
| 280 | module_put(mtd->owner); |
| 281 | out_unlock: |
| 282 | mutex_unlock(&mtd_table_mutex); |
| 283 | return ERR_PTR(err); |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 284 | } |
| 285 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | void put_mtd_device(struct mtd_info *mtd) |
| 287 | { |
| 288 | int c; |
| 289 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 290 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | c = --mtd->usecount; |
Artem Bityutskiy | 9fe912c | 2006-10-11 14:52:45 +0300 | [diff] [blame] | 292 | if (mtd->put_device) |
| 293 | mtd->put_device(mtd); |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 294 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | BUG_ON(c < 0); |
| 296 | |
| 297 | module_put(mtd->owner); |
| 298 | } |
| 299 | |
| 300 | /* default_mtd_writev - default mtd writev method for MTD devices that |
| 301 | * dont implement their own |
| 302 | */ |
| 303 | |
| 304 | int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, |
| 305 | unsigned long count, loff_t to, size_t *retlen) |
| 306 | { |
| 307 | unsigned long i; |
| 308 | size_t totlen = 0, thislen; |
| 309 | int ret = 0; |
| 310 | |
| 311 | if(!mtd->write) { |
| 312 | ret = -EROFS; |
| 313 | } else { |
| 314 | for (i=0; i<count; i++) { |
| 315 | if (!vecs[i].iov_len) |
| 316 | continue; |
| 317 | ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); |
| 318 | totlen += thislen; |
| 319 | if (ret || thislen != vecs[i].iov_len) |
| 320 | break; |
| 321 | to += vecs[i].iov_len; |
| 322 | } |
| 323 | } |
| 324 | if (retlen) |
| 325 | *retlen = totlen; |
| 326 | return ret; |
| 327 | } |
| 328 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | EXPORT_SYMBOL(add_mtd_device); |
| 330 | EXPORT_SYMBOL(del_mtd_device); |
| 331 | EXPORT_SYMBOL(get_mtd_device); |
Artem Bityutskiy | 7799308 | 2006-10-11 14:52:44 +0300 | [diff] [blame] | 332 | EXPORT_SYMBOL(get_mtd_device_nm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | EXPORT_SYMBOL(put_mtd_device); |
| 334 | EXPORT_SYMBOL(register_mtd_user); |
| 335 | EXPORT_SYMBOL(unregister_mtd_user); |
| 336 | EXPORT_SYMBOL(default_mtd_writev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
Pavel Machek | 2d2dce0 | 2006-03-31 02:29:49 -0800 | [diff] [blame] | 338 | #ifdef CONFIG_PROC_FS |
| 339 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | /*====================================================================*/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | /* Support for /proc/mtd */ |
| 342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | static struct proc_dir_entry *proc_mtd; |
| 344 | |
| 345 | static inline int mtd_proc_info (char *buf, int i) |
| 346 | { |
| 347 | struct mtd_info *this = mtd_table[i]; |
| 348 | |
| 349 | if (!this) |
| 350 | return 0; |
| 351 | |
| 352 | return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size, |
| 353 | this->erasesize, this->name); |
| 354 | } |
| 355 | |
| 356 | static int mtd_read_proc (char *page, char **start, off_t off, int count, |
| 357 | int *eof, void *data_unused) |
| 358 | { |
| 359 | int len, l, i; |
| 360 | off_t begin = 0; |
| 361 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 362 | mutex_lock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | |
| 364 | len = sprintf(page, "dev: size erasesize name\n"); |
| 365 | for (i=0; i< MAX_MTD_DEVICES; i++) { |
| 366 | |
| 367 | l = mtd_proc_info(page + len, i); |
| 368 | len += l; |
| 369 | if (len+begin > off+count) |
| 370 | goto done; |
| 371 | if (len+begin < off) { |
| 372 | begin += len; |
| 373 | len = 0; |
| 374 | } |
| 375 | } |
| 376 | |
| 377 | *eof = 1; |
| 378 | |
| 379 | done: |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 380 | mutex_unlock(&mtd_table_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | if (off >= len+begin) |
| 382 | return 0; |
| 383 | *start = page + (off-begin); |
| 384 | return ((count < begin+len-off) ? count : begin+len-off); |
| 385 | } |
| 386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | /*====================================================================*/ |
| 388 | /* Init code */ |
| 389 | |
| 390 | static int __init init_mtd(void) |
| 391 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | if ((proc_mtd = create_proc_entry( "mtd", 0, NULL ))) |
| 393 | proc_mtd->read_proc = mtd_read_proc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | return 0; |
| 395 | } |
| 396 | |
| 397 | static void __exit cleanup_mtd(void) |
| 398 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | if (proc_mtd) |
| 400 | remove_proc_entry( "mtd", NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
| 402 | |
| 403 | module_init(init_mtd); |
| 404 | module_exit(cleanup_mtd); |
| 405 | |
Pavel Machek | 2d2dce0 | 2006-03-31 02:29:49 -0800 | [diff] [blame] | 406 | #endif /* CONFIG_PROC_FS */ |
| 407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | |
| 409 | MODULE_LICENSE("GPL"); |
| 410 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 411 | MODULE_DESCRIPTION("Core MTD registration and access routines"); |