drivers/usb/gadget/configfs.c

   1 #include <linux/configfs.h>
   2 #include <linux/module.h>
   3 #include <linux/slab.h>
   4 #include <linux/device.h>
   5 #include <linux/nls.h>
   6 #include <linux/usb/composite.h>
   7 #include <linux/usb/gadget_configfs.h>
   8 #include "configfs.h"
   9 #include "u_f.h"
  10
  11 int check_user_usb_string(const char *name,
  12                 struct usb_gadget_strings *stringtab_dev)
  13 {
  14         unsigned primary_lang;
  15         unsigned sub_lang;
  16         u16 num;
  17         int ret;
  18
  19         ret = kstrtou16(name, 0, &num);
  20         if (ret)
  21                 return ret;
  22
  23         primary_lang = num & 0x3ff;
  24         sub_lang = num >> 10;
  25
  26         /* simple sanity check for valid langid */
  27         switch (primary_lang) {
  28         case 0:
  29         case 0x62 ... 0xfe:
  30         case 0x100 ... 0x3ff:
  31                 return -EINVAL;
  32         }
  33         if (!sub_lang)
  34                 return -EINVAL;
  35
  36         stringtab_dev->language = num;
  37         return 0;
  38 }
  39
  40 #define MAX_NAME_LEN    40
  41 #define MAX_USB_STRING_LANGS 2
  42
  43 struct gadget_info {
  44         struct config_group group;
  45         struct config_group functions_group;
  46         struct config_group configs_group;
  47         struct config_group strings_group;
  48         struct config_group os_desc_group;
  49         struct config_group *default_groups[5];
  50
  51         struct mutex lock;
  52         struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
  53         struct list_head string_list;
  54         struct list_head available_func;
  55
  56         const char *udc_name;
  57 #ifdef CONFIG_USB_OTG
  58         struct usb_otg_descriptor otg;
  59 #endif
  60         struct usb_composite_driver composite;
  61         struct usb_composite_dev cdev;
  62         bool use_os_desc;
  63         char b_vendor_code;
  64         char qw_sign[OS_STRING_QW_SIGN_LEN];
  65 };
  66
  67 struct config_usb_cfg {
  68         struct config_group group;
  69         struct config_group strings_group;
  70         struct config_group *default_groups[2];
  71         struct list_head string_list;
  72         struct usb_configuration c;
  73         struct list_head func_list;
  74         struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
  75 };
  76
  77 struct gadget_strings {
  78         struct usb_gadget_strings stringtab_dev;
  79         struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
  80         char *manufacturer;
  81         char *product;
  82         char *serialnumber;
  83
  84         struct config_group group;
  85         struct list_head list;
  86 };
  87
  88 struct os_desc {
  89         struct config_group group;
  90 };
  91
  92 struct gadget_config_name {
  93         struct usb_gadget_strings stringtab_dev;
  94         struct usb_string strings;
  95         char *configuration;
  96
  97         struct config_group group;
  98         struct list_head list;
  99 };
 100
 101 static int usb_string_copy(const char *s, char **s_copy)
 102 {
 103         int ret;
 104         char *str;
 105         char *copy = *s_copy;
 106         ret = strlen(s);
 107         if (ret > 126)
 108                 return -EOVERFLOW;
 109
 110         str = kstrdup(s, GFP_KERNEL);
 111         if (!str)
 112                 return -ENOMEM;
 113         if (str[ret - 1] == '\n')
 114                 str[ret - 1] = '\0';
 115         kfree(copy);
 116         *s_copy = str;
 117         return 0;
 118 }
 119
 120 CONFIGFS_ATTR_STRUCT(gadget_info);
 121 CONFIGFS_ATTR_STRUCT(config_usb_cfg);
 122
 123 #define GI_DEVICE_DESC_ITEM_ATTR(name)  \
 124         static struct gadget_info_attribute gadget_cdev_desc_##name = \
 125                 __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
 126                                 gadget_dev_desc_##name##_show,          \
 127                                 gadget_dev_desc_##name##_store)
 128
 129 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)      \
 130         static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
 131                         char *page)     \
 132 {       \
 133         return sprintf(page, "0x%02x\n", gi->cdev.desc.__name); \
 134 }
 135
 136 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)     \
 137         static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
 138                         char *page)     \
 139 {       \
 140         return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
 141 }
 142
 143
 144 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)               \
 145         static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
 146                 const char *page, size_t len)           \
 147 {                                                       \
 148         u8 val;                                         \
 149         int ret;                                        \
 150         ret = kstrtou8(page, 0, &val);                  \
 151         if (ret)                                        \
 152                 return ret;                             \
 153         gi->cdev.desc._name = val;                      \
 154         return len;                                     \
 155 }
 156
 157 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)      \
 158         static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
 159                 const char *page, size_t len)           \
 160 {                                                       \
 161         u16 val;                                        \
 162         int ret;                                        \
 163         ret = kstrtou16(page, 0, &val);                 \
 164         if (ret)                                        \
 165                 return ret;                             \
 166         gi->cdev.desc._name = cpu_to_le16p(&val);       \
 167         return len;                                     \
 168 }
 169
 170 #define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)  \
 171         GI_DEVICE_DESC_SIMPLE_R_##_type(_name)  \
 172         GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
 173
 174 GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
 175 GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
 176 GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
 177 GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
 178 GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
 179 GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
 180 GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
 181 GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
 182
 183 static ssize_t is_valid_bcd(u16 bcd_val)
 184 {
 185         if ((bcd_val & 0xf) > 9)
 186                 return -EINVAL;
 187         if (((bcd_val >> 4) & 0xf) > 9)
 188                 return -EINVAL;
 189         if (((bcd_val >> 8) & 0xf) > 9)
 190                 return -EINVAL;
 191         if (((bcd_val >> 12) & 0xf) > 9)
 192                 return -EINVAL;
 193         return 0;
 194 }
 195
 196 static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
 197                 const char *page, size_t len)
 198 {
 199         u16 bcdDevice;
 200         int ret;
 201
 202         ret = kstrtou16(page, 0, &bcdDevice);
 203         if (ret)
 204                 return ret;
 205         ret = is_valid_bcd(bcdDevice);
 206         if (ret)
 207                 return ret;
 208
 209         gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
 210         return len;
 211 }
 212
 213 static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
 214                 const char *page, size_t len)
 215 {
 216         u16 bcdUSB;
 217         int ret;
 218
 219         ret = kstrtou16(page, 0, &bcdUSB);
 220         if (ret)
 221                 return ret;
 222         ret = is_valid_bcd(bcdUSB);
 223         if (ret)
 224                 return ret;
 225
 226         gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
 227         return len;
 228 }
 229
 230 static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
 231 {
 232         return sprintf(page, "%s\n", gi->udc_name ?: "");
 233 }
 234
 235 static int unregister_gadget(struct gadget_info *gi)
 236 {
 237         int ret;
 238
 239         if (!gi->udc_name)
 240                 return -ENODEV;
 241
 242         ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
 243         if (ret)
 244                 return ret;
 245         kfree(gi->udc_name);
 246         gi->udc_name = NULL;
 247         return 0;
 248 }
 249
 250 static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
 251                 const char *page, size_t len)
 252 {
 253         char *name;
 254         int ret;
 255
 256         name = kstrdup(page, GFP_KERNEL);
 257         if (!name)
 258                 return -ENOMEM;
 259         if (name[len - 1] == '\n')
 260                 name[len - 1] = '\0';
 261
 262         mutex_lock(&gi->lock);
 263
 264         if (!strlen(name)) {
 265                 ret = unregister_gadget(gi);
 266                 if (ret)
 267                         goto err;
 268         } else {
 269                 if (gi->udc_name) {
 270                         ret = -EBUSY;
 271                         goto err;
 272                 }
 273                 ret = udc_attach_driver(name, &gi->composite.gadget_driver);
 274                 if (ret)
 275                         goto err;
 276                 gi->udc_name = name;
 277         }
 278         mutex_unlock(&gi->lock);
 279         return len;
 280 err:
 281         kfree(name);
 282         mutex_unlock(&gi->lock);
 283         return ret;
 284 }
 285
 286 GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
 287 GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
 288 GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
 289 GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
 290 GI_DEVICE_DESC_ITEM_ATTR(idVendor);
 291 GI_DEVICE_DESC_ITEM_ATTR(idProduct);
 292 GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
 293 GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
 294 GI_DEVICE_DESC_ITEM_ATTR(UDC);
 295
 296 static struct configfs_attribute *gadget_root_attrs[] = {
 297         &gadget_cdev_desc_bDeviceClass.attr,
 298         &gadget_cdev_desc_bDeviceSubClass.attr,
 299         &gadget_cdev_desc_bDeviceProtocol.attr,
 300         &gadget_cdev_desc_bMaxPacketSize0.attr,
 301         &gadget_cdev_desc_idVendor.attr,
 302         &gadget_cdev_desc_idProduct.attr,
 303         &gadget_cdev_desc_bcdDevice.attr,
 304         &gadget_cdev_desc_bcdUSB.attr,
 305         &gadget_cdev_desc_UDC.attr,
 306         NULL,
 307 };
 308
 309 static inline struct gadget_info *to_gadget_info(struct config_item *item)
 310 {
 311          return container_of(to_config_group(item), struct gadget_info, group);
 312 }
 313
 314 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
 315 {
 316          return container_of(to_config_group(item), struct gadget_strings,
 317                          group);
 318 }
 319
 320 static inline struct gadget_config_name *to_gadget_config_name(
 321                 struct config_item *item)
 322 {
 323          return container_of(to_config_group(item), struct gadget_config_name,
 324                          group);
 325 }
 326
 327 static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
 328 {
 329         return container_of(to_config_group(item), struct config_usb_cfg,
 330                         group);
 331 }
 332
 333 static inline struct usb_function_instance *to_usb_function_instance(
 334                 struct config_item *item)
 335 {
 336          return container_of(to_config_group(item),
 337                          struct usb_function_instance, group);
 338 }
 339
 340 static void gadget_info_attr_release(struct config_item *item)
 341 {
 342         struct gadget_info *gi = to_gadget_info(item);
 343
 344         WARN_ON(!list_empty(&gi->cdev.configs));
 345         WARN_ON(!list_empty(&gi->string_list));
 346         WARN_ON(!list_empty(&gi->available_func));
 347         kfree(gi->composite.gadget_driver.function);
 348         kfree(gi);
 349 }
 350
 351 CONFIGFS_ATTR_OPS(gadget_info);
 352
 353 static struct configfs_item_operations gadget_root_item_ops = {
 354         .release                = gadget_info_attr_release,
 355         .show_attribute         = gadget_info_attr_show,
 356         .store_attribute        = gadget_info_attr_store,
 357 };
 358
 359 static void gadget_config_attr_release(struct config_item *item)
 360 {
 361         struct config_usb_cfg *cfg = to_config_usb_cfg(item);
 362
 363         WARN_ON(!list_empty(&cfg->c.functions));
 364         list_del(&cfg->c.list);
 365         kfree(cfg->c.label);
 366         kfree(cfg);
 367 }
 368
 369 static int config_usb_cfg_link(
 370         struct config_item *usb_cfg_ci,
 371         struct config_item *usb_func_ci)
 372 {
 373         struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
 374         struct usb_composite_dev *cdev = cfg->c.cdev;
 375         struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
 376
 377         struct config_group *group = to_config_group(usb_func_ci);
 378         struct usb_function_instance *fi = container_of(group,
 379                         struct usb_function_instance, group);
 380         struct usb_function_instance *a_fi;
 381         struct usb_function *f;
 382         int ret;
 383
 384         mutex_lock(&gi->lock);
 385         /*
 386          * Make sure this function is from within our _this_ gadget and not
 387          * from another gadget or a random directory.
 388          * Also a function instance can only be linked once.
 389          */
 390         list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
 391                 if (a_fi == fi)
 392                         break;
 393         }
 394         if (a_fi != fi) {
 395                 ret = -EINVAL;
 396                 goto out;
 397         }
 398
 399         list_for_each_entry(f, &cfg->func_list, list) {
 400                 if (f->fi == fi) {
 401                         ret = -EEXIST;
 402                         goto out;
 403                 }
 404         }
 405
 406         f = usb_get_function(fi);
 407         if (IS_ERR(f)) {
 408                 ret = PTR_ERR(f);
 409                 goto out;
 410         }
 411
 412         /* stash the function until we bind it to the gadget */
 413         list_add_tail(&f->list, &cfg->func_list);
 414         ret = 0;
 415 out:
 416         mutex_unlock(&gi->lock);
 417         return ret;
 418 }
 419
 420 static int config_usb_cfg_unlink(
 421         struct config_item *usb_cfg_ci,
 422         struct config_item *usb_func_ci)
 423 {
 424         struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
 425         struct usb_composite_dev *cdev = cfg->c.cdev;
 426         struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
 427
 428         struct config_group *group = to_config_group(usb_func_ci);
 429         struct usb_function_instance *fi = container_of(group,
 430                         struct usb_function_instance, group);
 431         struct usb_function *f;
 432
 433         /*
 434          * ideally I would like to forbid to unlink functions while a gadget is
 435          * bound to an UDC. Since this isn't possible at the moment, we simply
 436          * force an unbind, the function is available here and then we can
 437          * remove the function.
 438          */
 439         mutex_lock(&gi->lock);
 440         if (gi->udc_name)
 441                 unregister_gadget(gi);
 442         WARN_ON(gi->udc_name);
 443
 444         list_for_each_entry(f, &cfg->func_list, list) {
 445                 if (f->fi == fi) {
 446                         list_del(&f->list);
 447                         usb_put_function(f);
 448                         mutex_unlock(&gi->lock);
 449                         return 0;
 450                 }
 451         }
 452         mutex_unlock(&gi->lock);
 453         WARN(1, "Unable to locate function to unbind\n");
 454         return 0;
 455 }
 456
 457 CONFIGFS_ATTR_OPS(config_usb_cfg);
 458
 459 static struct configfs_item_operations gadget_config_item_ops = {
 460         .release                = gadget_config_attr_release,
 461         .show_attribute         = config_usb_cfg_attr_show,
 462         .store_attribute        = config_usb_cfg_attr_store,
 463         .allow_link             = config_usb_cfg_link,
 464         .drop_link              = config_usb_cfg_unlink,
 465 };
 466
 467
 468 static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
 469                 char *page)
 470 {
 471         return sprintf(page, "%u\n", cfg->c.MaxPower);
 472 }
 473
 474 static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
 475                 const char *page, size_t len)
 476 {
 477         u16 val;
 478         int ret;
 479         ret = kstrtou16(page, 0, &val);
 480         if (ret)
 481                 return ret;
 482         if (DIV_ROUND_UP(val, 8) > 0xff)
 483                 return -ERANGE;
 484         cfg->c.MaxPower = val;
 485         return len;
 486 }
 487
 488 static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
 489                 char *page)
 490 {
 491         return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
 492 }
 493
 494 static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
 495                 const char *page, size_t len)
 496 {
 497         u8 val;
 498         int ret;
 499         ret = kstrtou8(page, 0, &val);
 500         if (ret)
 501                 return ret;
 502         if (!(val & USB_CONFIG_ATT_ONE))
 503                 return -EINVAL;
 504         if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
 505                                 USB_CONFIG_ATT_WAKEUP))
 506                 return -EINVAL;
 507         cfg->c.bmAttributes = val;
 508         return len;
 509 }
 510
 511 #define CFG_CONFIG_DESC_ITEM_ATTR(name) \
 512         static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
 513                 __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
 514                                 gadget_config_desc_##name##_show,       \
 515                                 gadget_config_desc_##name##_store)
 516
 517 CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
 518 CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
 519
 520 static struct configfs_attribute *gadget_config_attrs[] = {
 521         &gadget_usb_cfg_MaxPower.attr,
 522         &gadget_usb_cfg_bmAttributes.attr,
 523         NULL,
 524 };
 525
 526 static struct config_item_type gadget_config_type = {
 527         .ct_item_ops    = &gadget_config_item_ops,
 528         .ct_attrs       = gadget_config_attrs,
 529         .ct_owner       = THIS_MODULE,
 530 };
 531
 532 static struct config_item_type gadget_root_type = {
 533         .ct_item_ops    = &gadget_root_item_ops,
 534         .ct_attrs       = gadget_root_attrs,
 535         .ct_owner       = THIS_MODULE,
 536 };
 537
 538 static void composite_init_dev(struct usb_composite_dev *cdev)
 539 {
 540         spin_lock_init(&cdev->lock);
 541         INIT_LIST_HEAD(&cdev->configs);
 542         INIT_LIST_HEAD(&cdev->gstrings);
 543 }
 544
 545 static struct config_group *function_make(
 546                 struct config_group *group,
 547                 const char *name)
 548 {
 549         struct gadget_info *gi;
 550         struct usb_function_instance *fi;
 551         char buf[MAX_NAME_LEN];
 552         char *func_name;
 553         char *instance_name;
 554         int ret;
 555
 556         ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
 557         if (ret >= MAX_NAME_LEN)
 558                 return ERR_PTR(-ENAMETOOLONG);
 559
 560         func_name = buf;
 561         instance_name = strchr(func_name, '.');
 562         if (!instance_name) {
 563                 pr_err("Unable to locate . in FUNC.INSTANCE\n");
 564                 return ERR_PTR(-EINVAL);
 565         }
 566         *instance_name = '\0';
 567         instance_name++;
 568
 569         fi = usb_get_function_instance(func_name);
 570         if (IS_ERR(fi))
 571                 return ERR_CAST(fi);
 572
 573         ret = config_item_set_name(&fi->group.cg_item, name);
 574         if (ret) {
 575                 usb_put_function_instance(fi);
 576                 return ERR_PTR(ret);
 577         }
 578         if (fi->set_inst_name) {
 579                 ret = fi->set_inst_name(fi, instance_name);
 580                 if (ret) {
 581                         usb_put_function_instance(fi);
 582                         return ERR_PTR(ret);
 583                 }
 584         }
 585
 586         gi = container_of(group, struct gadget_info, functions_group);
 587
 588         mutex_lock(&gi->lock);
 589         list_add_tail(&fi->cfs_list, &gi->available_func);
 590         mutex_unlock(&gi->lock);
 591         return &fi->group;
 592 }
 593
 594 static void function_drop(
 595                 struct config_group *group,
 596                 struct config_item *item)
 597 {
 598         struct usb_function_instance *fi = to_usb_function_instance(item);
 599         struct gadget_info *gi;
 600
 601         gi = container_of(group, struct gadget_info, functions_group);
 602
 603         mutex_lock(&gi->lock);
 604         list_del(&fi->cfs_list);
 605         mutex_unlock(&gi->lock);
 606         config_item_put(item);
 607 }
 608
 609 static struct configfs_group_operations functions_ops = {
 610         .make_group     = &function_make,
 611         .drop_item      = &function_drop,
 612 };
 613
 614 static struct config_item_type functions_type = {
 615         .ct_group_ops   = &functions_ops,
 616         .ct_owner       = THIS_MODULE,
 617 };
 618
 619 CONFIGFS_ATTR_STRUCT(gadget_config_name);
 620 GS_STRINGS_RW(gadget_config_name, configuration);
 621
 622 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
 623         &gadget_config_name_configuration.attr,
 624         NULL,
 625 };
 626
 627 static void gadget_config_name_attr_release(struct config_item *item)
 628 {
 629         struct gadget_config_name *cn = to_gadget_config_name(item);
 630
 631         kfree(cn->configuration);
 632
 633         list_del(&cn->list);
 634         kfree(cn);
 635 }
 636
 637 USB_CONFIG_STRING_RW_OPS(gadget_config_name);
 638 USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
 639
 640 static struct config_group *config_desc_make(
 641                 struct config_group *group,
 642                 const char *name)
 643 {
 644         struct gadget_info *gi;
 645         struct config_usb_cfg *cfg;
 646         char buf[MAX_NAME_LEN];
 647         char *num_str;
 648         u8 num;
 649         int ret;
 650
 651         gi = container_of(group, struct gadget_info, configs_group);
 652         ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
 653         if (ret >= MAX_NAME_LEN)
 654                 return ERR_PTR(-ENAMETOOLONG);
 655
 656         num_str = strchr(buf, '.');
 657         if (!num_str) {
 658                 pr_err("Unable to locate . in name.bConfigurationValue\n");
 659                 return ERR_PTR(-EINVAL);
 660         }
 661
 662         *num_str = '\0';
 663         num_str++;
 664
 665         if (!strlen(buf))
 666                 return ERR_PTR(-EINVAL);
 667
 668         ret = kstrtou8(num_str, 0, &num);
 669         if (ret)
 670                 return ERR_PTR(ret);
 671
 672         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 673         if (!cfg)
 674                 return ERR_PTR(-ENOMEM);
 675         cfg->c.label = kstrdup(buf, GFP_KERNEL);
 676         if (!cfg->c.label) {
 677                 ret = -ENOMEM;
 678                 goto err;
 679         }
 680         cfg->c.bConfigurationValue = num;
 681         cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
 682         cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
 683         INIT_LIST_HEAD(&cfg->string_list);
 684         INIT_LIST_HEAD(&cfg->func_list);
 685
 686         cfg->group.default_groups = cfg->default_groups;
 687         cfg->default_groups[0] = &cfg->strings_group;
 688
 689         config_group_init_type_name(&cfg->group, name,
 690                                 &gadget_config_type);
 691         config_group_init_type_name(&cfg->strings_group, "strings",
 692                         &gadget_config_name_strings_type);
 693
 694         ret = usb_add_config_only(&gi->cdev, &cfg->c);
 695         if (ret)
 696                 goto err;
 697
 698         return &cfg->group;
 699 err:
 700         kfree(cfg->c.label);
 701         kfree(cfg);
 702         return ERR_PTR(ret);
 703 }
 704
 705 static void config_desc_drop(
 706                 struct config_group *group,
 707                 struct config_item *item)
 708 {
 709         config_item_put(item);
 710 }
 711
 712 static struct configfs_group_operations config_desc_ops = {
 713         .make_group     = &config_desc_make,
 714         .drop_item      = &config_desc_drop,
 715 };
 716
 717 static struct config_item_type config_desc_type = {
 718         .ct_group_ops   = &config_desc_ops,
 719         .ct_owner       = THIS_MODULE,
 720 };
 721
 722 CONFIGFS_ATTR_STRUCT(gadget_strings);
 723 GS_STRINGS_RW(gadget_strings, manufacturer);
 724 GS_STRINGS_RW(gadget_strings, product);
 725 GS_STRINGS_RW(gadget_strings, serialnumber);
 726
 727 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
 728         &gadget_strings_manufacturer.attr,
 729         &gadget_strings_product.attr,
 730         &gadget_strings_serialnumber.attr,
 731         NULL,
 732 };
 733
 734 static void gadget_strings_attr_release(struct config_item *item)
 735 {
 736         struct gadget_strings *gs = to_gadget_strings(item);
 737
 738         kfree(gs->manufacturer);
 739         kfree(gs->product);
 740         kfree(gs->serialnumber);
 741
 742         list_del(&gs->list);
 743         kfree(gs);
 744 }
 745
 746 USB_CONFIG_STRING_RW_OPS(gadget_strings);
 747 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
 748
 749 static inline struct os_desc *to_os_desc(struct config_item *item)
 750 {
 751         return container_of(to_config_group(item), struct os_desc, group);
 752 }
 753
 754 CONFIGFS_ATTR_STRUCT(os_desc);
 755 CONFIGFS_ATTR_OPS(os_desc);
 756
 757 static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
 758 {
 759         struct gadget_info *gi;
 760
 761         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 762
 763         return sprintf(page, "%d", gi->use_os_desc);
 764 }
 765
 766 static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
 767                                  size_t len)
 768 {
 769         struct gadget_info *gi;
 770         int ret;
 771         bool use;
 772
 773         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 774
 775         mutex_lock(&gi->lock);
 776         ret = strtobool(page, &use);
 777         if (!ret) {
 778                 gi->use_os_desc = use;
 779                 ret = len;
 780         }
 781         mutex_unlock(&gi->lock);
 782
 783         return ret;
 784 }
 785
 786 static struct os_desc_attribute os_desc_use =
 787         __CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
 788                         os_desc_use_show,
 789                         os_desc_use_store);
 790
 791 static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
 792 {
 793         struct gadget_info *gi;
 794
 795         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 796
 797         return sprintf(page, "%d", gi->b_vendor_code);
 798 }
 799
 800 static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
 801                                            const char *page, size_t len)
 802 {
 803         struct gadget_info *gi;
 804         int ret;
 805         u8 b_vendor_code;
 806
 807         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 808
 809         mutex_lock(&gi->lock);
 810         ret = kstrtou8(page, 0, &b_vendor_code);
 811         if (!ret) {
 812                 gi->b_vendor_code = b_vendor_code;
 813                 ret = len;
 814         }
 815         mutex_unlock(&gi->lock);
 816
 817         return ret;
 818 }
 819
 820 static struct os_desc_attribute os_desc_b_vendor_code =
 821         __CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
 822                         os_desc_b_vendor_code_show,
 823                         os_desc_b_vendor_code_store);
 824
 825 static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
 826 {
 827         struct gadget_info *gi;
 828
 829         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 830
 831         memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
 832
 833         return OS_STRING_QW_SIGN_LEN;
 834 }
 835
 836 static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
 837                                      size_t len)
 838 {
 839         struct gadget_info *gi;
 840         int res, l;
 841
 842         gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
 843         l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
 844         if (page[l - 1] == '\n')
 845                 --l;
 846
 847         mutex_lock(&gi->lock);
 848         res = utf8s_to_utf16s(page, l,
 849                               UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
 850                               OS_STRING_QW_SIGN_LEN);
 851         if (res > 0)
 852                 res = len;
 853         mutex_unlock(&gi->lock);
 854
 855         return res;
 856 }
 857
 858 static struct os_desc_attribute os_desc_qw_sign =
 859         __CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
 860                         os_desc_qw_sign_show,
 861                         os_desc_qw_sign_store);
 862
 863 static struct configfs_attribute *os_desc_attrs[] = {
 864         &os_desc_use.attr,
 865         &os_desc_b_vendor_code.attr,
 866         &os_desc_qw_sign.attr,
 867         NULL,
 868 };
 869
 870 static void os_desc_attr_release(struct config_item *item)
 871 {
 872         struct os_desc *os_desc = to_os_desc(item);
 873         kfree(os_desc);
 874 }
 875
 876 static int os_desc_link(struct config_item *os_desc_ci,
 877                         struct config_item *usb_cfg_ci)
 878 {
 879         struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
 880                                         struct gadget_info, os_desc_group);
 881         struct usb_composite_dev *cdev = &gi->cdev;
 882         struct config_usb_cfg *c_target =
 883                 container_of(to_config_group(usb_cfg_ci),
 884                              struct config_usb_cfg, group);
 885         struct usb_configuration *c;
 886         int ret;
 887
 888         mutex_lock(&gi->lock);
 889         list_for_each_entry(c, &cdev->configs, list) {
 890                 if (c == &c_target->c)
 891                         break;
 892         }
 893         if (c != &c_target->c) {
 894                 ret = -EINVAL;
 895                 goto out;
 896         }
 897
 898         if (cdev->os_desc_config) {
 899                 ret = -EBUSY;
 900                 goto out;
 901         }
 902
 903         cdev->os_desc_config = &c_target->c;
 904         ret = 0;
 905
 906 out:
 907         mutex_unlock(&gi->lock);
 908         return ret;
 909 }
 910
 911 static int os_desc_unlink(struct config_item *os_desc_ci,
 912                           struct config_item *usb_cfg_ci)
 913 {
 914         struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
 915                                         struct gadget_info, os_desc_group);
 916         struct usb_composite_dev *cdev = &gi->cdev;
 917
 918         mutex_lock(&gi->lock);
 919         if (gi->udc_name)
 920                 unregister_gadget(gi);
 921         cdev->os_desc_config = NULL;
 922         WARN_ON(gi->udc_name);
 923         mutex_unlock(&gi->lock);
 924         return 0;
 925 }
 926
 927 static struct configfs_item_operations os_desc_ops = {
 928         .release                = os_desc_attr_release,
 929         .show_attribute         = os_desc_attr_show,
 930         .store_attribute        = os_desc_attr_store,
 931         .allow_link             = os_desc_link,
 932         .drop_link              = os_desc_unlink,
 933 };
 934
 935 static struct config_item_type os_desc_type = {
 936         .ct_item_ops    = &os_desc_ops,
 937         .ct_attrs       = os_desc_attrs,
 938         .ct_owner       = THIS_MODULE,
 939 };
 940
 941 CONFIGFS_ATTR_STRUCT(usb_os_desc);
 942 CONFIGFS_ATTR_OPS(usb_os_desc);
 943
 944 static struct configfs_item_operations interf_item_ops = {
 945         .show_attribute         = usb_os_desc_attr_show,
 946         .store_attribute        = usb_os_desc_attr_store,
 947 };
 948
 949 static ssize_t rndis_grp_compatible_id_show(struct usb_os_desc *desc,
 950                                             char *page)
 951 {
 952         memcpy(page, desc->ext_compat_id, 8);
 953         return 8;
 954 }
 955
 956 static ssize_t rndis_grp_compatible_id_store(struct usb_os_desc *desc,
 957                                              const char *page, size_t len)
 958 {
 959         int l;
 960
 961         l = min_t(int, 8, len);
 962         if (page[l - 1] == '\n')
 963                 --l;
 964         if (desc->opts_mutex)
 965                 mutex_lock(desc->opts_mutex);
 966         memcpy(desc->ext_compat_id, page, l);
 967         desc->ext_compat_id[l] = '\0';
 968
 969         if (desc->opts_mutex)
 970                 mutex_unlock(desc->opts_mutex);
 971
 972         return len;
 973 }
 974
 975 static struct usb_os_desc_attribute rndis_grp_attr_compatible_id =
 976         __CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
 977                         rndis_grp_compatible_id_show,
 978                         rndis_grp_compatible_id_store);
 979
 980 static ssize_t rndis_grp_sub_compatible_id_show(struct usb_os_desc *desc,
 981                                                 char *page)
 982 {
 983         memcpy(page, desc->ext_compat_id + 8, 8);
 984         return 8;
 985 }
 986
 987 static ssize_t rndis_grp_sub_compatible_id_store(struct usb_os_desc *desc,
 988                                                  const char *page, size_t len)
 989 {
 990         int l;
 991
 992         l = min_t(int, 8, len);
 993         if (page[l - 1] == '\n')
 994                 --l;
 995         if (desc->opts_mutex)
 996                 mutex_lock(desc->opts_mutex);
 997         memcpy(desc->ext_compat_id + 8, page, l);
 998         desc->ext_compat_id[l + 8] = '\0';
 999
1000         if (desc->opts_mutex)
1001                 mutex_unlock(desc->opts_mutex);
1002
1003         return len;
1004 }
1005
1006 static struct usb_os_desc_attribute rndis_grp_attr_sub_compatible_id =
1007         __CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
1008                         rndis_grp_sub_compatible_id_show,
1009                         rndis_grp_sub_compatible_id_store);
1010
1011 static struct configfs_attribute *interf_grp_attrs[] = {
1012         &rndis_grp_attr_compatible_id.attr,
1013         &rndis_grp_attr_sub_compatible_id.attr,
1014         NULL
1015 };
1016
1017 int usb_os_desc_prepare_interf_dir(struct config_group *parent,
1018                                    int n_interf,
1019                                    struct usb_os_desc **desc,
1020                                    struct module *owner)
1021 {
1022         struct config_group **f_default_groups, *os_desc_group,
1023                                 **interface_groups;
1024         struct config_item_type *os_desc_type, *interface_type;
1025
1026         vla_group(data_chunk);
1027         vla_item(data_chunk, struct config_group *, f_default_groups, 2);
1028         vla_item(data_chunk, struct config_group, os_desc_group, 1);
1029         vla_item(data_chunk, struct config_group *, interface_groups,
1030                  n_interf + 1);
1031         vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
1032         vla_item(data_chunk, struct config_item_type, interface_type, 1);
1033
1034         char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
1035         if (!vlabuf)
1036                 return -ENOMEM;
1037
1038         f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
1039         os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
1040         os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
1041         interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
1042         interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
1043
1044         parent->default_groups = f_default_groups;
1045         os_desc_type->ct_owner = owner;
1046         config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
1047         f_default_groups[0] = os_desc_group;
1048
1049         os_desc_group->default_groups = interface_groups;
1050         interface_type->ct_item_ops = &interf_item_ops;
1051         interface_type->ct_attrs = interf_grp_attrs;
1052         interface_type->ct_owner = owner;
1053
1054         while (n_interf--) {
1055                 struct usb_os_desc *d;
1056
1057                 d = desc[n_interf];
1058                 config_group_init_type_name(&d->group, "", interface_type);
1059                 config_item_set_name(&d->group.cg_item, "interface.%d",
1060                                      n_interf);
1061                 interface_groups[n_interf] = &d->group;
1062         }
1063
1064         return 0;
1065 }
1066 EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
1067
1068 static int configfs_do_nothing(struct usb_composite_dev *cdev)
1069 {
1070         WARN_ON(1);
1071         return -EINVAL;
1072 }
1073
1074 int composite_dev_prepare(struct usb_composite_driver *composite,
1075                 struct usb_composite_dev *dev);
1076
1077 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
1078                                   struct usb_ep *ep0);
1079
1080 static void purge_configs_funcs(struct gadget_info *gi)
1081 {
1082         struct usb_configuration        *c;
1083
1084         list_for_each_entry(c, &gi->cdev.configs, list) {
1085                 struct usb_function *f, *tmp;
1086                 struct config_usb_cfg *cfg;
1087
1088                 cfg = container_of(c, struct config_usb_cfg, c);
1089
1090                 list_for_each_entry_safe(f, tmp, &c->functions, list) {
1091
1092                         list_move_tail(&f->list, &cfg->func_list);
1093                         if (f->unbind) {
1094                                 dev_err(&gi->cdev.gadget->dev, "unbind function"
1095                                                 " '%s'/%p\n", f->name, f);
1096                                 f->unbind(c, f);
1097                         }
1098                 }
1099                 c->next_interface_id = 0;
1100                 c->superspeed = 0;
1101                 c->highspeed = 0;
1102                 c->fullspeed = 0;
1103         }
1104 }
1105
1106 static int configfs_composite_bind(struct usb_gadget *gadget,
1107                 struct usb_gadget_driver *gdriver)
1108 {
1109         struct usb_composite_driver     *composite = to_cdriver(gdriver);
1110         struct gadget_info              *gi = container_of(composite,
1111                                                 struct gadget_info, composite);
1112         struct usb_composite_dev        *cdev = &gi->cdev;
1113         struct usb_configuration        *c;
1114         struct usb_string               *s;
1115         unsigned                        i;
1116         int                             ret;
1117
1118         /* the gi->lock is hold by the caller */
1119         cdev->gadget = gadget;
1120         set_gadget_data(gadget, cdev);
1121         ret = composite_dev_prepare(composite, cdev);
1122         if (ret)
1123                 return ret;
1124         /* and now the gadget bind */
1125         ret = -EINVAL;
1126
1127         if (list_empty(&gi->cdev.configs)) {
1128                 pr_err("Need at least one configuration in %s.\n",
1129                                 gi->composite.name);
1130                 goto err_comp_cleanup;
1131         }
1132
1133
1134         list_for_each_entry(c, &gi->cdev.configs, list) {
1135                 struct config_usb_cfg *cfg;
1136
1137                 cfg = container_of(c, struct config_usb_cfg, c);
1138                 if (list_empty(&cfg->func_list)) {
1139                         pr_err("Config %s/%d of %s needs at least one function.\n",
1140                               c->label, c->bConfigurationValue,
1141                               gi->composite.name);
1142                         goto err_comp_cleanup;
1143                 }
1144         }
1145
1146         /* init all strings */
1147         if (!list_empty(&gi->string_list)) {
1148                 struct gadget_strings *gs;
1149
1150                 i = 0;
1151                 list_for_each_entry(gs, &gi->string_list, list) {
1152
1153                         gi->gstrings[i] = &gs->stringtab_dev;
1154                         gs->stringtab_dev.strings = gs->strings;
1155                         gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
1156                                 gs->manufacturer;
1157                         gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
1158                         gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
1159                         i++;
1160                 }
1161                 gi->gstrings[i] = NULL;
1162                 s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
1163                                 USB_GADGET_FIRST_AVAIL_IDX);
1164                 if (IS_ERR(s)) {
1165                         ret = PTR_ERR(s);
1166                         goto err_comp_cleanup;
1167                 }
1168
1169                 gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
1170                 gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
1171                 gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
1172         }
1173
1174         if (gi->use_os_desc) {
1175                 cdev->use_os_string = true;
1176                 cdev->b_vendor_code = gi->b_vendor_code;
1177                 memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
1178         }
1179
1180         /* Go through all configs, attach all functions */
1181         list_for_each_entry(c, &gi->cdev.configs, list) {
1182                 struct config_usb_cfg *cfg;
1183                 struct usb_function *f;
1184                 struct usb_function *tmp;
1185                 struct gadget_config_name *cn;
1186
1187                 cfg = container_of(c, struct config_usb_cfg, c);
1188                 if (!list_empty(&cfg->string_list)) {
1189                         i = 0;
1190                         list_for_each_entry(cn, &cfg->string_list, list) {
1191                                 cfg->gstrings[i] = &cn->stringtab_dev;
1192                                 cn->stringtab_dev.strings = &cn->strings;
1193                                 cn->strings.s = cn->configuration;
1194                                 i++;
1195                         }
1196                         cfg->gstrings[i] = NULL;
1197                         s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
1198                         if (IS_ERR(s)) {
1199                                 ret = PTR_ERR(s);
1200                                 goto err_comp_cleanup;
1201                         }
1202                         c->iConfiguration = s[0].id;
1203                 }
1204
1205                 list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
1206                         list_del(&f->list);
1207                         ret = usb_add_function(c, f);
1208                         if (ret) {
1209                                 list_add(&f->list, &cfg->func_list);
1210                                 goto err_purge_funcs;
1211                         }
1212                 }
1213                 usb_ep_autoconfig_reset(cdev->gadget);
1214         }
1215         if (cdev->use_os_string) {
1216                 ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
1217                 if (ret)
1218                         goto err_purge_funcs;
1219         }
1220
1221         usb_ep_autoconfig_reset(cdev->gadget);
1222         return 0;
1223
1224 err_purge_funcs:
1225         purge_configs_funcs(gi);
1226 err_comp_cleanup:
1227         composite_dev_cleanup(cdev);
1228         return ret;
1229 }
1230
1231 static void configfs_composite_unbind(struct usb_gadget *gadget)
1232 {
1233         struct usb_composite_dev        *cdev;
1234         struct gadget_info              *gi;
1235
1236         /* the gi->lock is hold by the caller */
1237
1238         cdev = get_gadget_data(gadget);
1239         gi = container_of(cdev, struct gadget_info, cdev);
1240
1241         purge_configs_funcs(gi);
1242         composite_dev_cleanup(cdev);
1243         usb_ep_autoconfig_reset(cdev->gadget);
1244         cdev->gadget = NULL;
1245         set_gadget_data(gadget, NULL);
1246 }
1247
1248 static const struct usb_gadget_driver configfs_driver_template = {
1249         .bind           = configfs_composite_bind,
1250         .unbind         = configfs_composite_unbind,
1251
1252         .setup          = composite_setup,
1253         .disconnect     = composite_disconnect,
1254
1255         .max_speed      = USB_SPEED_SUPER,
1256         .driver = {
1257                 .owner          = THIS_MODULE,
1258                 .name           = "configfs-gadget",
1259         },
1260 };
1261
1262 static struct config_group *gadgets_make(
1263                 struct config_group *group,
1264                 const char *name)
1265 {
1266         struct gadget_info *gi;
1267
1268         gi = kzalloc(sizeof(*gi), GFP_KERNEL);
1269         if (!gi)
1270                 return ERR_PTR(-ENOMEM);
1271
1272         gi->group.default_groups = gi->default_groups;
1273         gi->group.default_groups[0] = &gi->functions_group;
1274         gi->group.default_groups[1] = &gi->configs_group;
1275         gi->group.default_groups[2] = &gi->strings_group;
1276         gi->group.default_groups[3] = &gi->os_desc_group;
1277
1278         config_group_init_type_name(&gi->functions_group, "functions",
1279                         &functions_type);
1280         config_group_init_type_name(&gi->configs_group, "configs",
1281                         &config_desc_type);
1282         config_group_init_type_name(&gi->strings_group, "strings",
1283                         &gadget_strings_strings_type);
1284         config_group_init_type_name(&gi->os_desc_group, "os_desc",
1285                         &os_desc_type);
1286
1287         gi->composite.bind = configfs_do_nothing;
1288         gi->composite.unbind = configfs_do_nothing;
1289         gi->composite.suspend = NULL;
1290         gi->composite.resume = NULL;
1291         gi->composite.max_speed = USB_SPEED_SUPER;
1292
1293         mutex_init(&gi->lock);
1294         INIT_LIST_HEAD(&gi->string_list);
1295         INIT_LIST_HEAD(&gi->available_func);
1296
1297         composite_init_dev(&gi->cdev);
1298         gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
1299         gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
1300         gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
1301
1302         gi->composite.gadget_driver = configfs_driver_template;
1303
1304         gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
1305         gi->composite.name = gi->composite.gadget_driver.function;
1306
1307         if (!gi->composite.gadget_driver.function)
1308                 goto err;
1309
1310 #ifdef CONFIG_USB_OTG
1311         gi->otg.bLength = sizeof(struct usb_otg_descriptor);
1312         gi->otg.bDescriptorType = USB_DT_OTG;
1313         gi->otg.bmAttributes = USB_OTG_SRP | USB_OTG_HNP;
1314 #endif
1315
1316         config_group_init_type_name(&gi->group, name,
1317                                 &gadget_root_type);
1318         return &gi->group;
1319 err:
1320         kfree(gi);
1321         return ERR_PTR(-ENOMEM);
1322 }
1323
1324 static void gadgets_drop(struct config_group *group, struct config_item *item)
1325 {
1326         config_item_put(item);
1327 }
1328
1329 static struct configfs_group_operations gadgets_ops = {
1330         .make_group     = &gadgets_make,
1331         .drop_item      = &gadgets_drop,
1332 };
1333
1334 static struct config_item_type gadgets_type = {
1335         .ct_group_ops   = &gadgets_ops,
1336         .ct_owner       = THIS_MODULE,
1337 };
1338
1339 static struct configfs_subsystem gadget_subsys = {
1340         .su_group = {
1341                 .cg_item = {
1342                         .ci_namebuf = "usb_gadget",
1343                         .ci_type = &gadgets_type,
1344                 },
1345         },
1346         .su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
1347 };
1348
1349 void unregister_gadget_item(struct config_item *item)
1350 {
1351         struct gadget_info *gi = to_gadget_info(item);
1352
1353         unregister_gadget(gi);
1354 }
1355 EXPORT_SYMBOL_GPL(unregister_gadget_item);
1356
1357 static int __init gadget_cfs_init(void)
1358 {
1359         int ret;
1360
1361         config_group_init(&gadget_subsys.su_group);
1362
1363         ret = configfs_register_subsystem(&gadget_subsys);
1364         return ret;
1365 }
1366 module_init(gadget_cfs_init);
1367
1368 static void __exit gadget_cfs_exit(void)
1369 {
1370         configfs_unregister_subsystem(&gadget_subsys);
1371 }
1372 module_exit(gadget_cfs_exit);