linux/drivers/usb/gadget/configfs.c
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   1#include <linux/configfs.h>
   2#include <linux/module.h>
   3#include <linux/slab.h>
   4#include <linux/device.h>
   5#include <linux/usb/composite.h>
   6#include <linux/usb/gadget_configfs.h>
   7
   8int check_user_usb_string(const char *name,
   9                struct usb_gadget_strings *stringtab_dev)
  10{
  11        unsigned primary_lang;
  12        unsigned sub_lang;
  13        u16 num;
  14        int ret;
  15
  16        ret = kstrtou16(name, 0, &num);
  17        if (ret)
  18                return ret;
  19
  20        primary_lang = num & 0x3ff;
  21        sub_lang = num >> 10;
  22
  23        /* simple sanity check for valid langid */
  24        switch (primary_lang) {
  25        case 0:
  26        case 0x62 ... 0xfe:
  27        case 0x100 ... 0x3ff:
  28                return -EINVAL;
  29        }
  30        if (!sub_lang)
  31                return -EINVAL;
  32
  33        stringtab_dev->language = num;
  34        return 0;
  35}
  36
  37#define MAX_NAME_LEN    40
  38#define MAX_USB_STRING_LANGS 2
  39
  40struct gadget_info {
  41        struct config_group group;
  42        struct config_group functions_group;
  43        struct config_group configs_group;
  44        struct config_group strings_group;
  45        struct config_group *default_groups[4];
  46
  47        struct mutex lock;
  48        struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
  49        struct list_head string_list;
  50        struct list_head available_func;
  51
  52        const char *udc_name;
  53#ifdef CONFIG_USB_OTG
  54        struct usb_otg_descriptor otg;
  55#endif
  56        struct usb_composite_driver composite;
  57        struct usb_composite_dev cdev;
  58};
  59
  60struct config_usb_cfg {
  61        struct config_group group;
  62        struct config_group strings_group;
  63        struct config_group *default_groups[2];
  64        struct list_head string_list;
  65        struct usb_configuration c;
  66        struct list_head func_list;
  67        struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
  68};
  69
  70struct gadget_strings {
  71        struct usb_gadget_strings stringtab_dev;
  72        struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
  73        char *manufacturer;
  74        char *product;
  75        char *serialnumber;
  76
  77        struct config_group group;
  78        struct list_head list;
  79};
  80
  81struct gadget_config_name {
  82        struct usb_gadget_strings stringtab_dev;
  83        struct usb_string strings;
  84        char *configuration;
  85
  86        struct config_group group;
  87        struct list_head list;
  88};
  89
  90static int usb_string_copy(const char *s, char **s_copy)
  91{
  92        int ret;
  93        char *str;
  94        char *copy = *s_copy;
  95        ret = strlen(s);
  96        if (ret > 126)
  97                return -EOVERFLOW;
  98
  99        str = kstrdup(s, GFP_KERNEL);
 100        if (!str)
 101                return -ENOMEM;
 102        if (str[ret - 1] == '\n')
 103                str[ret - 1] = '\0';
 104        kfree(copy);
 105        *s_copy = str;
 106        return 0;
 107}
 108
 109CONFIGFS_ATTR_STRUCT(gadget_info);
 110CONFIGFS_ATTR_STRUCT(config_usb_cfg);
 111
 112#define GI_DEVICE_DESC_ITEM_ATTR(name)  \
 113        static struct gadget_info_attribute gadget_cdev_desc_##name = \
 114                __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
 115                                gadget_dev_desc_##name##_show,          \
 116                                gadget_dev_desc_##name##_store)
 117
 118#define GI_DEVICE_DESC_SIMPLE_R_u8(__name)      \
 119        static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
 120                        char *page)     \
 121{       \
 122        return sprintf(page, "0x%02x\n", gi->cdev.desc.__name); \
 123}
 124
 125#define GI_DEVICE_DESC_SIMPLE_R_u16(__name)     \
 126        static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
 127                        char *page)     \
 128{       \
 129        return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
 130}
 131
 132
 133#define GI_DEVICE_DESC_SIMPLE_W_u8(_name)               \
 134        static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
 135                const char *page, size_t len)           \
 136{                                                       \
 137        u8 val;                                         \
 138        int ret;                                        \
 139        ret = kstrtou8(page, 0, &val);                  \
 140        if (ret)                                        \
 141                return ret;                             \
 142        gi->cdev.desc._name = val;                      \
 143        return len;                                     \
 144}
 145
 146#define GI_DEVICE_DESC_SIMPLE_W_u16(_name)      \
 147        static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
 148                const char *page, size_t len)           \
 149{                                                       \
 150        u16 val;                                        \
 151        int ret;                                        \
 152        ret = kstrtou16(page, 0, &val);                 \
 153        if (ret)                                        \
 154                return ret;                             \
 155        gi->cdev.desc._name = cpu_to_le16p(&val);       \
 156        return len;                                     \
 157}
 158
 159#define GI_DEVICE_DESC_SIMPLE_RW(_name, _type)  \
 160        GI_DEVICE_DESC_SIMPLE_R_##_type(_name)  \
 161        GI_DEVICE_DESC_SIMPLE_W_##_type(_name)
 162
 163GI_DEVICE_DESC_SIMPLE_R_u16(bcdUSB);
 164GI_DEVICE_DESC_SIMPLE_RW(bDeviceClass, u8);
 165GI_DEVICE_DESC_SIMPLE_RW(bDeviceSubClass, u8);
 166GI_DEVICE_DESC_SIMPLE_RW(bDeviceProtocol, u8);
 167GI_DEVICE_DESC_SIMPLE_RW(bMaxPacketSize0, u8);
 168GI_DEVICE_DESC_SIMPLE_RW(idVendor, u16);
 169GI_DEVICE_DESC_SIMPLE_RW(idProduct, u16);
 170GI_DEVICE_DESC_SIMPLE_R_u16(bcdDevice);
 171
 172static ssize_t is_valid_bcd(u16 bcd_val)
 173{
 174        if ((bcd_val & 0xf) > 9)
 175                return -EINVAL;
 176        if (((bcd_val >> 4) & 0xf) > 9)
 177                return -EINVAL;
 178        if (((bcd_val >> 8) & 0xf) > 9)
 179                return -EINVAL;
 180        if (((bcd_val >> 12) & 0xf) > 9)
 181                return -EINVAL;
 182        return 0;
 183}
 184
 185static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
 186                const char *page, size_t len)
 187{
 188        u16 bcdDevice;
 189        int ret;
 190
 191        ret = kstrtou16(page, 0, &bcdDevice);
 192        if (ret)
 193                return ret;
 194        ret = is_valid_bcd(bcdDevice);
 195        if (ret)
 196                return ret;
 197
 198        gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
 199        return len;
 200}
 201
 202static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
 203                const char *page, size_t len)
 204{
 205        u16 bcdUSB;
 206        int ret;
 207
 208        ret = kstrtou16(page, 0, &bcdUSB);
 209        if (ret)
 210                return ret;
 211        ret = is_valid_bcd(bcdUSB);
 212        if (ret)
 213                return ret;
 214
 215        gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
 216        return len;
 217}
 218
 219static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
 220{
 221        return sprintf(page, "%s\n", gi->udc_name ?: "");
 222}
 223
 224static int unregister_gadget(struct gadget_info *gi)
 225{
 226        int ret;
 227
 228        if (!gi->udc_name)
 229                return -ENODEV;
 230
 231        ret = usb_gadget_unregister_driver(&gi->composite.gadget_driver);
 232        if (ret)
 233                return ret;
 234        kfree(gi->udc_name);
 235        gi->udc_name = NULL;
 236        return 0;
 237}
 238
 239static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
 240                const char *page, size_t len)
 241{
 242        char *name;
 243        int ret;
 244
 245        name = kstrdup(page, GFP_KERNEL);
 246        if (!name)
 247                return -ENOMEM;
 248        if (name[len - 1] == '\n')
 249                name[len - 1] = '\0';
 250
 251        mutex_lock(&gi->lock);
 252
 253        if (!strlen(name)) {
 254                ret = unregister_gadget(gi);
 255                if (ret)
 256                        goto err;
 257        } else {
 258                if (gi->udc_name) {
 259                        ret = -EBUSY;
 260                        goto err;
 261                }
 262                ret = udc_attach_driver(name, &gi->composite.gadget_driver);
 263                if (ret)
 264                        goto err;
 265                gi->udc_name = name;
 266        }
 267        mutex_unlock(&gi->lock);
 268        return len;
 269err:
 270        kfree(name);
 271        mutex_unlock(&gi->lock);
 272        return ret;
 273}
 274
 275GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
 276GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
 277GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
 278GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
 279GI_DEVICE_DESC_ITEM_ATTR(idVendor);
 280GI_DEVICE_DESC_ITEM_ATTR(idProduct);
 281GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
 282GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
 283GI_DEVICE_DESC_ITEM_ATTR(UDC);
 284
 285static struct configfs_attribute *gadget_root_attrs[] = {
 286        &gadget_cdev_desc_bDeviceClass.attr,
 287        &gadget_cdev_desc_bDeviceSubClass.attr,
 288        &gadget_cdev_desc_bDeviceProtocol.attr,
 289        &gadget_cdev_desc_bMaxPacketSize0.attr,
 290        &gadget_cdev_desc_idVendor.attr,
 291        &gadget_cdev_desc_idProduct.attr,
 292        &gadget_cdev_desc_bcdDevice.attr,
 293        &gadget_cdev_desc_bcdUSB.attr,
 294        &gadget_cdev_desc_UDC.attr,
 295        NULL,
 296};
 297
 298static inline struct gadget_info *to_gadget_info(struct config_item *item)
 299{
 300         return container_of(to_config_group(item), struct gadget_info, group);
 301}
 302
 303static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
 304{
 305         return container_of(to_config_group(item), struct gadget_strings,
 306                         group);
 307}
 308
 309static inline struct gadget_config_name *to_gadget_config_name(
 310                struct config_item *item)
 311{
 312         return container_of(to_config_group(item), struct gadget_config_name,
 313                         group);
 314}
 315
 316static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
 317{
 318        return container_of(to_config_group(item), struct config_usb_cfg,
 319                        group);
 320}
 321
 322static inline struct usb_function_instance *to_usb_function_instance(
 323                struct config_item *item)
 324{
 325         return container_of(to_config_group(item),
 326                         struct usb_function_instance, group);
 327}
 328
 329static void gadget_info_attr_release(struct config_item *item)
 330{
 331        struct gadget_info *gi = to_gadget_info(item);
 332
 333        WARN_ON(!list_empty(&gi->cdev.configs));
 334        WARN_ON(!list_empty(&gi->string_list));
 335        WARN_ON(!list_empty(&gi->available_func));
 336        kfree(gi->composite.gadget_driver.function);
 337        kfree(gi);
 338}
 339
 340CONFIGFS_ATTR_OPS(gadget_info);
 341
 342static struct configfs_item_operations gadget_root_item_ops = {
 343        .release                = gadget_info_attr_release,
 344        .show_attribute         = gadget_info_attr_show,
 345        .store_attribute        = gadget_info_attr_store,
 346};
 347
 348static void gadget_config_attr_release(struct config_item *item)
 349{
 350        struct config_usb_cfg *cfg = to_config_usb_cfg(item);
 351
 352        WARN_ON(!list_empty(&cfg->c.functions));
 353        list_del(&cfg->c.list);
 354        kfree(cfg->c.label);
 355        kfree(cfg);
 356}
 357
 358static int config_usb_cfg_link(
 359        struct config_item *usb_cfg_ci,
 360        struct config_item *usb_func_ci)
 361{
 362        struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
 363        struct usb_composite_dev *cdev = cfg->c.cdev;
 364        struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
 365
 366        struct config_group *group = to_config_group(usb_func_ci);
 367        struct usb_function_instance *fi = container_of(group,
 368                        struct usb_function_instance, group);
 369        struct usb_function_instance *a_fi;
 370        struct usb_function *f;
 371        int ret;
 372
 373        mutex_lock(&gi->lock);
 374        /*
 375         * Make sure this function is from within our _this_ gadget and not
 376         * from another gadget or a random directory.
 377         * Also a function instance can only be linked once.
 378         */
 379        list_for_each_entry(a_fi, &gi->available_func, cfs_list) {
 380                if (a_fi == fi)
 381                        break;
 382        }
 383        if (a_fi != fi) {
 384                ret = -EINVAL;
 385                goto out;
 386        }
 387
 388        list_for_each_entry(f, &cfg->func_list, list) {
 389                if (f->fi == fi) {
 390                        ret = -EEXIST;
 391                        goto out;
 392                }
 393        }
 394
 395        f = usb_get_function(fi);
 396        if (IS_ERR(f)) {
 397                ret = PTR_ERR(f);
 398                goto out;
 399        }
 400
 401        /* stash the function until we bind it to the gadget */
 402        list_add_tail(&f->list, &cfg->func_list);
 403        ret = 0;
 404out:
 405        mutex_unlock(&gi->lock);
 406        return ret;
 407}
 408
 409static int config_usb_cfg_unlink(
 410        struct config_item *usb_cfg_ci,
 411        struct config_item *usb_func_ci)
 412{
 413        struct config_usb_cfg *cfg = to_config_usb_cfg(usb_cfg_ci);
 414        struct usb_composite_dev *cdev = cfg->c.cdev;
 415        struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);
 416
 417        struct config_group *group = to_config_group(usb_func_ci);
 418        struct usb_function_instance *fi = container_of(group,
 419                        struct usb_function_instance, group);
 420        struct usb_function *f;
 421
 422        /*
 423         * ideally I would like to forbid to unlink functions while a gadget is
 424         * bound to an UDC. Since this isn't possible at the moment, we simply
 425         * force an unbind, the function is available here and then we can
 426         * remove the function.
 427         */
 428        mutex_lock(&gi->lock);
 429        if (gi->udc_name)
 430                unregister_gadget(gi);
 431        WARN_ON(gi->udc_name);
 432
 433        list_for_each_entry(f, &cfg->func_list, list) {
 434                if (f->fi == fi) {
 435                        list_del(&f->list);
 436                        usb_put_function(f);
 437                        mutex_unlock(&gi->lock);
 438                        return 0;
 439                }
 440        }
 441        mutex_unlock(&gi->lock);
 442        WARN(1, "Unable to locate function to unbind\n");
 443        return 0;
 444}
 445
 446CONFIGFS_ATTR_OPS(config_usb_cfg);
 447
 448static struct configfs_item_operations gadget_config_item_ops = {
 449        .release                = gadget_config_attr_release,
 450        .show_attribute         = config_usb_cfg_attr_show,
 451        .store_attribute        = config_usb_cfg_attr_store,
 452        .allow_link             = config_usb_cfg_link,
 453        .drop_link              = config_usb_cfg_unlink,
 454};
 455
 456
 457static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
 458                char *page)
 459{
 460        return sprintf(page, "%u\n", cfg->c.MaxPower);
 461}
 462
 463static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
 464                const char *page, size_t len)
 465{
 466        u16 val;
 467        int ret;
 468        ret = kstrtou16(page, 0, &val);
 469        if (ret)
 470                return ret;
 471        if (DIV_ROUND_UP(val, 8) > 0xff)
 472                return -ERANGE;
 473        cfg->c.MaxPower = val;
 474        return len;
 475}
 476
 477static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
 478                char *page)
 479{
 480        return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
 481}
 482
 483static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
 484                const char *page, size_t len)
 485{
 486        u8 val;
 487        int ret;
 488        ret = kstrtou8(page, 0, &val);
 489        if (ret)
 490                return ret;
 491        if (!(val & USB_CONFIG_ATT_ONE))
 492                return -EINVAL;
 493        if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
 494                                USB_CONFIG_ATT_WAKEUP))
 495                return -EINVAL;
 496        cfg->c.bmAttributes = val;
 497        return len;
 498}
 499
 500#define CFG_CONFIG_DESC_ITEM_ATTR(name) \
 501        static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
 502                __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
 503                                gadget_config_desc_##name##_show,       \
 504                                gadget_config_desc_##name##_store)
 505
 506CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
 507CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
 508
 509static struct configfs_attribute *gadget_config_attrs[] = {
 510        &gadget_usb_cfg_MaxPower.attr,
 511        &gadget_usb_cfg_bmAttributes.attr,
 512        NULL,
 513};
 514
 515static struct config_item_type gadget_config_type = {
 516        .ct_item_ops    = &gadget_config_item_ops,
 517        .ct_attrs       = gadget_config_attrs,
 518        .ct_owner       = THIS_MODULE,
 519};
 520
 521static struct config_item_type gadget_root_type = {
 522        .ct_item_ops    = &gadget_root_item_ops,
 523        .ct_attrs       = gadget_root_attrs,
 524        .ct_owner       = THIS_MODULE,
 525};
 526
 527static void composite_init_dev(struct usb_composite_dev *cdev)
 528{
 529        spin_lock_init(&cdev->lock);
 530        INIT_LIST_HEAD(&cdev->configs);
 531        INIT_LIST_HEAD(&cdev->gstrings);
 532}
 533
 534static struct config_group *function_make(
 535                struct config_group *group,
 536                const char *name)
 537{
 538        struct gadget_info *gi;
 539        struct usb_function_instance *fi;
 540        char buf[MAX_NAME_LEN];
 541        char *func_name;
 542        char *instance_name;
 543        int ret;
 544
 545        ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
 546        if (ret >= MAX_NAME_LEN)
 547                return ERR_PTR(-ENAMETOOLONG);
 548
 549        func_name = buf;
 550        instance_name = strchr(func_name, '.');
 551        if (!instance_name) {
 552                pr_err("Unable to locate . in FUNC.INSTANCE\n");
 553                return ERR_PTR(-EINVAL);
 554        }
 555        *instance_name = '\0';
 556        instance_name++;
 557
 558        fi = usb_get_function_instance(func_name);
 559        if (IS_ERR(fi))
 560                return ERR_PTR(PTR_ERR(fi));
 561
 562        ret = config_item_set_name(&fi->group.cg_item, name);
 563        if (ret) {
 564                usb_put_function_instance(fi);
 565                return ERR_PTR(ret);
 566        }
 567
 568        gi = container_of(group, struct gadget_info, functions_group);
 569
 570        mutex_lock(&gi->lock);
 571        list_add_tail(&fi->cfs_list, &gi->available_func);
 572        mutex_unlock(&gi->lock);
 573        return &fi->group;
 574}
 575
 576static void function_drop(
 577                struct config_group *group,
 578                struct config_item *item)
 579{
 580        struct usb_function_instance *fi = to_usb_function_instance(item);
 581        struct gadget_info *gi;
 582
 583        gi = container_of(group, struct gadget_info, functions_group);
 584
 585        mutex_lock(&gi->lock);
 586        list_del(&fi->cfs_list);
 587        mutex_unlock(&gi->lock);
 588        config_item_put(item);
 589}
 590
 591static struct configfs_group_operations functions_ops = {
 592        .make_group     = &function_make,
 593        .drop_item      = &function_drop,
 594};
 595
 596static struct config_item_type functions_type = {
 597        .ct_group_ops   = &functions_ops,
 598        .ct_owner       = THIS_MODULE,
 599};
 600
 601CONFIGFS_ATTR_STRUCT(gadget_config_name);
 602GS_STRINGS_RW(gadget_config_name, configuration);
 603
 604static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
 605        &gadget_config_name_configuration.attr,
 606        NULL,
 607};
 608
 609static void gadget_config_name_attr_release(struct config_item *item)
 610{
 611        struct gadget_config_name *cn = to_gadget_config_name(item);
 612
 613        kfree(cn->configuration);
 614
 615        list_del(&cn->list);
 616        kfree(cn);
 617}
 618
 619USB_CONFIG_STRING_RW_OPS(gadget_config_name);
 620USB_CONFIG_STRINGS_LANG(gadget_config_name, config_usb_cfg);
 621
 622static struct config_group *config_desc_make(
 623                struct config_group *group,
 624                const char *name)
 625{
 626        struct gadget_info *gi;
 627        struct config_usb_cfg *cfg;
 628        char buf[MAX_NAME_LEN];
 629        char *num_str;
 630        u8 num;
 631        int ret;
 632
 633        gi = container_of(group, struct gadget_info, configs_group);
 634        ret = snprintf(buf, MAX_NAME_LEN, "%s", name);
 635        if (ret >= MAX_NAME_LEN)
 636                return ERR_PTR(-ENAMETOOLONG);
 637
 638        num_str = strchr(buf, '.');
 639        if (!num_str) {
 640                pr_err("Unable to locate . in name.bConfigurationValue\n");
 641                return ERR_PTR(-EINVAL);
 642        }
 643
 644        *num_str = '\0';
 645        num_str++;
 646
 647        if (!strlen(buf))
 648                return ERR_PTR(-EINVAL);
 649
 650        ret = kstrtou8(num_str, 0, &num);
 651        if (ret)
 652                return ERR_PTR(ret);
 653
 654        cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 655        if (!cfg)
 656                return ERR_PTR(-ENOMEM);
 657        cfg->c.label = kstrdup(buf, GFP_KERNEL);
 658        if (!cfg->c.label) {
 659                ret = -ENOMEM;
 660                goto err;
 661        }
 662        cfg->c.bConfigurationValue = num;
 663        cfg->c.MaxPower = CONFIG_USB_GADGET_VBUS_DRAW;
 664        cfg->c.bmAttributes = USB_CONFIG_ATT_ONE;
 665        INIT_LIST_HEAD(&cfg->string_list);
 666        INIT_LIST_HEAD(&cfg->func_list);
 667
 668        cfg->group.default_groups = cfg->default_groups;
 669        cfg->default_groups[0] = &cfg->strings_group;
 670
 671        config_group_init_type_name(&cfg->group, name,
 672                                &gadget_config_type);
 673        config_group_init_type_name(&cfg->strings_group, "strings",
 674                        &gadget_config_name_strings_type);
 675
 676        ret = usb_add_config_only(&gi->cdev, &cfg->c);
 677        if (ret)
 678                goto err;
 679
 680        return &cfg->group;
 681err:
 682        kfree(cfg->c.label);
 683        kfree(cfg);
 684        return ERR_PTR(ret);
 685}
 686
 687static void config_desc_drop(
 688                struct config_group *group,
 689                struct config_item *item)
 690{
 691        config_item_put(item);
 692}
 693
 694static struct configfs_group_operations config_desc_ops = {
 695        .make_group     = &config_desc_make,
 696        .drop_item      = &config_desc_drop,
 697};
 698
 699static struct config_item_type config_desc_type = {
 700        .ct_group_ops   = &config_desc_ops,
 701        .ct_owner       = THIS_MODULE,
 702};
 703
 704CONFIGFS_ATTR_STRUCT(gadget_strings);
 705GS_STRINGS_RW(gadget_strings, manufacturer);
 706GS_STRINGS_RW(gadget_strings, product);
 707GS_STRINGS_RW(gadget_strings, serialnumber);
 708
 709static struct configfs_attribute *gadget_strings_langid_attrs[] = {
 710        &gadget_strings_manufacturer.attr,
 711        &gadget_strings_product.attr,
 712        &gadget_strings_serialnumber.attr,
 713        NULL,
 714};
 715
 716static void gadget_strings_attr_release(struct config_item *item)
 717{
 718        struct gadget_strings *gs = to_gadget_strings(item);
 719
 720        kfree(gs->manufacturer);
 721        kfree(gs->product);
 722        kfree(gs->serialnumber);
 723
 724        list_del(&gs->list);
 725        kfree(gs);
 726}
 727
 728USB_CONFIG_STRING_RW_OPS(gadget_strings);
 729USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
 730
 731static int configfs_do_nothing(struct usb_composite_dev *cdev)
 732{
 733        WARN_ON(1);
 734        return -EINVAL;
 735}
 736
 737int composite_dev_prepare(struct usb_composite_driver *composite,
 738                struct usb_composite_dev *dev);
 739
 740static void purge_configs_funcs(struct gadget_info *gi)
 741{
 742        struct usb_configuration        *c;
 743
 744        list_for_each_entry(c, &gi->cdev.configs, list) {
 745                struct usb_function *f, *tmp;
 746                struct config_usb_cfg *cfg;
 747
 748                cfg = container_of(c, struct config_usb_cfg, c);
 749
 750                list_for_each_entry_safe(f, tmp, &c->functions, list) {
 751
 752                        list_move_tail(&f->list, &cfg->func_list);
 753                        if (f->unbind) {
 754                                dev_err(&gi->cdev.gadget->dev, "unbind function"
 755                                                " '%s'/%p\n", f->name, f);
 756                                f->unbind(c, f);
 757                        }
 758                }
 759                c->next_interface_id = 0;
 760                c->superspeed = 0;
 761                c->highspeed = 0;
 762                c->fullspeed = 0;
 763        }
 764}
 765
 766static int configfs_composite_bind(struct usb_gadget *gadget,
 767                struct usb_gadget_driver *gdriver)
 768{
 769        struct usb_composite_driver     *composite = to_cdriver(gdriver);
 770        struct gadget_info              *gi = container_of(composite,
 771                                                struct gadget_info, composite);
 772        struct usb_composite_dev        *cdev = &gi->cdev;
 773        struct usb_configuration        *c;
 774        struct usb_string               *s;
 775        unsigned                        i;
 776        int                             ret;
 777
 778        /* the gi->lock is hold by the caller */
 779        cdev->gadget = gadget;
 780        set_gadget_data(gadget, cdev);
 781        ret = composite_dev_prepare(composite, cdev);
 782        if (ret)
 783                return ret;
 784        /* and now the gadget bind */
 785        ret = -EINVAL;
 786
 787        if (list_empty(&gi->cdev.configs)) {
 788                pr_err("Need atleast one configuration in %s.\n",
 789                                gi->composite.name);
 790                goto err_comp_cleanup;
 791        }
 792
 793
 794        list_for_each_entry(c, &gi->cdev.configs, list) {
 795                struct config_usb_cfg *cfg;
 796
 797                cfg = container_of(c, struct config_usb_cfg, c);
 798                if (list_empty(&cfg->func_list)) {
 799                        pr_err("Config %s/%d of %s needs atleast one function.\n",
 800                              c->label, c->bConfigurationValue,
 801                              gi->composite.name);
 802                        goto err_comp_cleanup;
 803                }
 804        }
 805
 806        /* init all strings */
 807        if (!list_empty(&gi->string_list)) {
 808                struct gadget_strings *gs;
 809
 810                i = 0;
 811                list_for_each_entry(gs, &gi->string_list, list) {
 812
 813                        gi->gstrings[i] = &gs->stringtab_dev;
 814                        gs->stringtab_dev.strings = gs->strings;
 815                        gs->strings[USB_GADGET_MANUFACTURER_IDX].s =
 816                                gs->manufacturer;
 817                        gs->strings[USB_GADGET_PRODUCT_IDX].s = gs->product;
 818                        gs->strings[USB_GADGET_SERIAL_IDX].s = gs->serialnumber;
 819                        i++;
 820                }
 821                gi->gstrings[i] = NULL;
 822                s = usb_gstrings_attach(&gi->cdev, gi->gstrings,
 823                                USB_GADGET_FIRST_AVAIL_IDX);
 824                if (IS_ERR(s)) {
 825                        ret = PTR_ERR(s);
 826                        goto err_comp_cleanup;
 827                }
 828
 829                gi->cdev.desc.iManufacturer = s[USB_GADGET_MANUFACTURER_IDX].id;
 830                gi->cdev.desc.iProduct = s[USB_GADGET_PRODUCT_IDX].id;
 831                gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
 832        }
 833
 834        /* Go through all configs, attach all functions */
 835        list_for_each_entry(c, &gi->cdev.configs, list) {
 836                struct config_usb_cfg *cfg;
 837                struct usb_function *f;
 838                struct usb_function *tmp;
 839                struct gadget_config_name *cn;
 840
 841                cfg = container_of(c, struct config_usb_cfg, c);
 842                if (!list_empty(&cfg->string_list)) {
 843                        i = 0;
 844                        list_for_each_entry(cn, &cfg->string_list, list) {
 845                                cfg->gstrings[i] = &cn->stringtab_dev;
 846                                cn->stringtab_dev.strings = &cn->strings;
 847                                cn->strings.s = cn->configuration;
 848                                i++;
 849                        }
 850                        cfg->gstrings[i] = NULL;
 851                        s = usb_gstrings_attach(&gi->cdev, cfg->gstrings, 1);
 852                        if (IS_ERR(s)) {
 853                                ret = PTR_ERR(s);
 854                                goto err_comp_cleanup;
 855                        }
 856                        c->iConfiguration = s[0].id;
 857                }
 858
 859                list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
 860                        list_del(&f->list);
 861                        ret = usb_add_function(c, f);
 862                        if (ret) {
 863                                list_add(&f->list, &cfg->func_list);
 864                                goto err_purge_funcs;
 865                        }
 866                }
 867                usb_ep_autoconfig_reset(cdev->gadget);
 868        }
 869        usb_ep_autoconfig_reset(cdev->gadget);
 870        return 0;
 871
 872err_purge_funcs:
 873        purge_configs_funcs(gi);
 874err_comp_cleanup:
 875        composite_dev_cleanup(cdev);
 876        return ret;
 877}
 878
 879static void configfs_composite_unbind(struct usb_gadget *gadget)
 880{
 881        struct usb_composite_dev        *cdev;
 882        struct gadget_info              *gi;
 883
 884        /* the gi->lock is hold by the caller */
 885
 886        cdev = get_gadget_data(gadget);
 887        gi = container_of(cdev, struct gadget_info, cdev);
 888
 889        purge_configs_funcs(gi);
 890        composite_dev_cleanup(cdev);
 891        usb_ep_autoconfig_reset(cdev->gadget);
 892        cdev->gadget = NULL;
 893        set_gadget_data(gadget, NULL);
 894}
 895
 896static const struct usb_gadget_driver configfs_driver_template = {
 897        .bind           = configfs_composite_bind,
 898        .unbind         = configfs_composite_unbind,
 899
 900        .setup          = composite_setup,
 901        .disconnect     = composite_disconnect,
 902
 903        .max_speed      = USB_SPEED_SUPER,
 904        .driver = {
 905                .owner          = THIS_MODULE,
 906                .name           = "configfs-gadget",
 907        },
 908};
 909
 910static struct config_group *gadgets_make(
 911                struct config_group *group,
 912                const char *name)
 913{
 914        struct gadget_info *gi;
 915
 916        gi = kzalloc(sizeof(*gi), GFP_KERNEL);
 917        if (!gi)
 918                return ERR_PTR(-ENOMEM);
 919
 920        gi->group.default_groups = gi->default_groups;
 921        gi->group.default_groups[0] = &gi->functions_group;
 922        gi->group.default_groups[1] = &gi->configs_group;
 923        gi->group.default_groups[2] = &gi->strings_group;
 924
 925        config_group_init_type_name(&gi->functions_group, "functions",
 926                        &functions_type);
 927        config_group_init_type_name(&gi->configs_group, "configs",
 928                        &config_desc_type);
 929        config_group_init_type_name(&gi->strings_group, "strings",
 930                        &gadget_strings_strings_type);
 931
 932        gi->composite.bind = configfs_do_nothing;
 933        gi->composite.unbind = configfs_do_nothing;
 934        gi->composite.suspend = NULL;
 935        gi->composite.resume = NULL;
 936        gi->composite.max_speed = USB_SPEED_SUPER;
 937
 938        mutex_init(&gi->lock);
 939        INIT_LIST_HEAD(&gi->string_list);
 940        INIT_LIST_HEAD(&gi->available_func);
 941
 942        composite_init_dev(&gi->cdev);
 943        gi->cdev.desc.bLength = USB_DT_DEVICE_SIZE;
 944        gi->cdev.desc.bDescriptorType = USB_DT_DEVICE;
 945        gi->cdev.desc.bcdDevice = cpu_to_le16(get_default_bcdDevice());
 946
 947        gi->composite.gadget_driver = configfs_driver_template;
 948
 949        gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
 950        gi->composite.name = gi->composite.gadget_driver.function;
 951
 952        if (!gi->composite.gadget_driver.function)
 953                goto err;
 954
 955#ifdef CONFIG_USB_OTG
 956        gi->otg.bLength = sizeof(struct usb_otg_descriptor);
 957        gi->otg.bDescriptorType = USB_DT_OTG;
 958        gi->otg.bmAttributes = USB_OTG_SRP | USB_OTG_HNP;
 959#endif
 960
 961        config_group_init_type_name(&gi->group, name,
 962                                &gadget_root_type);
 963        return &gi->group;
 964err:
 965        kfree(gi);
 966        return ERR_PTR(-ENOMEM);
 967}
 968
 969static void gadgets_drop(struct config_group *group, struct config_item *item)
 970{
 971        config_item_put(item);
 972}
 973
 974static struct configfs_group_operations gadgets_ops = {
 975        .make_group     = &gadgets_make,
 976        .drop_item      = &gadgets_drop,
 977};
 978
 979static struct config_item_type gadgets_type = {
 980        .ct_group_ops   = &gadgets_ops,
 981        .ct_owner       = THIS_MODULE,
 982};
 983
 984static struct configfs_subsystem gadget_subsys = {
 985        .su_group = {
 986                .cg_item = {
 987                        .ci_namebuf = "usb_gadget",
 988                        .ci_type = &gadgets_type,
 989                },
 990        },
 991        .su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
 992};
 993
 994static int __init gadget_cfs_init(void)
 995{
 996        int ret;
 997
 998        config_group_init(&gadget_subsys.su_group);
 999
1000        ret = configfs_register_subsystem(&gadget_subsys);
1001        return ret;
1002}
1003module_init(gadget_cfs_init);
1004
1005static void __exit gadget_cfs_exit(void)
1006{
1007        configfs_unregister_subsystem(&gadget_subsys);
1008}
1009module_exit(gadget_cfs_exit);
1010