drivers/usb/gadget/legacy/g_ffs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * g_ffs.c -- user mode file system API for USB composite function controllers
   4  *
   5  * Copyright (C) 2010 Samsung Electronics
   6  * Author: Michal Nazarewicz <mina86@mina86.com>
   7  */
   8
   9 #define pr_fmt(fmt) "g_ffs: " fmt
  10
  11 #include <linux/module.h>
  12
  13 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
  14 #include <linux/netdevice.h>
  15
  16 #  if defined USB_ETH_RNDIS
  17 #    undef USB_ETH_RNDIS
  18 #  endif
  19 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  20 #    define USB_ETH_RNDIS y
  21 #  endif
  22
  23 #  include "u_ecm.h"
  24 #  include "u_gether.h"
  25 #  ifdef USB_ETH_RNDIS
  26 #    include "u_rndis.h"
  27 #    include "rndis.h"
  28 #  endif
  29 #  include "u_ether.h"
  30
  31 USB_ETHERNET_MODULE_PARAMETERS();
  32
  33 #  ifdef CONFIG_USB_FUNCTIONFS_ETH
  34 static int eth_bind_config(struct usb_configuration *c);
  35 static struct usb_function_instance *fi_ecm;
  36 static struct usb_function *f_ecm;
  37 static struct usb_function_instance *fi_geth;
  38 static struct usb_function *f_geth;
  39 #  endif
  40 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  41 static int bind_rndis_config(struct usb_configuration *c);
  42 static struct usb_function_instance *fi_rndis;
  43 static struct usb_function *f_rndis;
  44 #  endif
  45 #endif
  46
  47 #include "u_fs.h"
  48
  49 #define DRIVER_NAME     "g_ffs"
  50 #define DRIVER_DESC     "USB Function Filesystem"
  51 #define DRIVER_VERSION  "24 Aug 2004"
  52
  53 MODULE_DESCRIPTION(DRIVER_DESC);
  54 MODULE_AUTHOR("Michal Nazarewicz");
  55 MODULE_LICENSE("GPL");
  56
  57 #define GFS_VENDOR_ID   0x1d6b  /* Linux Foundation */
  58 #define GFS_PRODUCT_ID  0x0105  /* FunctionFS Gadget */
  59
  60 #define GFS_MAX_DEVS    10
  61
  62 USB_GADGET_COMPOSITE_OPTIONS();
  63
  64 static struct usb_device_descriptor gfs_dev_desc = {
  65         .bLength                = sizeof gfs_dev_desc,
  66         .bDescriptorType        = USB_DT_DEVICE,
  67
  68         /* .bcdUSB = DYNAMIC */
  69         .bDeviceClass           = USB_CLASS_PER_INTERFACE,
  70
  71         .idVendor               = cpu_to_le16(GFS_VENDOR_ID),
  72         .idProduct              = cpu_to_le16(GFS_PRODUCT_ID),
  73 };
  74
  75 static char *func_names[GFS_MAX_DEVS];
  76 static unsigned int func_num;
  77
  78 module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
  79 MODULE_PARM_DESC(bDeviceClass, "USB Device class");
  80 module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
  81 MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
  82 module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
  83 MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
  84 module_param_array_named(functions, func_names, charp, &func_num, 0);
  85 MODULE_PARM_DESC(functions, "USB Functions list");
  86
  87 static const struct usb_descriptor_header *gfs_otg_desc[2];
  88
  89 /* String IDs are assigned dynamically */
  90 static struct usb_string gfs_strings[] = {
  91         [USB_GADGET_MANUFACTURER_IDX].s = "",
  92         [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
  93         [USB_GADGET_SERIAL_IDX].s = "",
  94 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  95         { .s = "FunctionFS + RNDIS" },
  96 #endif
  97 #ifdef CONFIG_USB_FUNCTIONFS_ETH
  98         { .s = "FunctionFS + ECM" },
  99 #endif
 100 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 101         { .s = "FunctionFS" },
 102 #endif
 103         {  } /* end of list */
 104 };
 105
 106 static struct usb_gadget_strings *gfs_dev_strings[] = {
 107         &(struct usb_gadget_strings) {
 108                 .language       = 0x0409,       /* en-us */
 109                 .strings        = gfs_strings,
 110         },
 111         NULL,
 112 };
 113
 114 struct gfs_configuration {
 115         struct usb_configuration c;
 116         int (*eth)(struct usb_configuration *c);
 117         int num;
 118 };
 119
 120 static struct gfs_configuration gfs_configurations[] = {
 121 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 122         {
 123                 .eth            = bind_rndis_config,
 124         },
 125 #endif
 126
 127 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 128         {
 129                 .eth            = eth_bind_config,
 130         },
 131 #endif
 132
 133 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 134         {
 135         },
 136 #endif
 137 };
 138
 139 static void *functionfs_acquire_dev(struct ffs_dev *dev);
 140 static void functionfs_release_dev(struct ffs_dev *dev);
 141 static int functionfs_ready_callback(struct ffs_data *ffs);
 142 static void functionfs_closed_callback(struct ffs_data *ffs);
 143 static int gfs_bind(struct usb_composite_dev *cdev);
 144 static int gfs_unbind(struct usb_composite_dev *cdev);
 145 static int gfs_do_config(struct usb_configuration *c);
 146
 147
 148 static struct usb_composite_driver gfs_driver = {
 149         .name           = DRIVER_NAME,
 150         .dev            = &gfs_dev_desc,
 151         .strings        = gfs_dev_strings,
 152         .max_speed      = USB_SPEED_SUPER,
 153         .bind           = gfs_bind,
 154         .unbind         = gfs_unbind,
 155 };
 156
 157 static unsigned int missing_funcs;
 158 static bool gfs_registered;
 159 static bool gfs_single_func;
 160 static struct usb_function_instance **fi_ffs;
 161 static struct usb_function **f_ffs[] = {
 162 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 163         NULL,
 164 #endif
 165
 166 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 167         NULL,
 168 #endif
 169
 170 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 171         NULL,
 172 #endif
 173 };
 174
 175 #define N_CONF ARRAY_SIZE(f_ffs)
 176
 177 static int __init gfs_init(void)
 178 {
 179         struct f_fs_opts *opts;
 180         int i;
 181         int ret = 0;
 182
 183         ENTER();
 184
 185         if (func_num < 2) {
 186                 gfs_single_func = true;
 187                 func_num = 1;
 188         }
 189
 190         /*
 191          * Allocate in one chunk for easier maintenance
 192          */
 193         f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
 194         if (!f_ffs[0]) {
 195                 ret = -ENOMEM;
 196                 goto no_func;
 197         }
 198         for (i = 1; i < N_CONF; ++i)
 199                 f_ffs[i] = f_ffs[0] + i * func_num;
 200
 201         fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
 202         if (!fi_ffs) {
 203                 ret = -ENOMEM;
 204                 goto no_func;
 205         }
 206
 207         for (i = 0; i < func_num; i++) {
 208                 fi_ffs[i] = usb_get_function_instance("ffs");
 209                 if (IS_ERR(fi_ffs[i])) {
 210                         ret = PTR_ERR(fi_ffs[i]);
 211                         --i;
 212                         goto no_dev;
 213                 }
 214                 opts = to_f_fs_opts(fi_ffs[i]);
 215                 if (gfs_single_func)
 216                         ret = ffs_single_dev(opts->dev);
 217                 else
 218                         ret = ffs_name_dev(opts->dev, func_names[i]);
 219                 if (ret)
 220                         goto no_dev;
 221                 opts->dev->ffs_ready_callback = functionfs_ready_callback;
 222                 opts->dev->ffs_closed_callback = functionfs_closed_callback;
 223                 opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
 224                 opts->dev->ffs_release_dev_callback = functionfs_release_dev;
 225                 opts->no_configfs = true;
 226         }
 227
 228         missing_funcs = func_num;
 229
 230         return 0;
 231 no_dev:
 232         while (i >= 0)
 233                 usb_put_function_instance(fi_ffs[i--]);
 234         kfree(fi_ffs);
 235 no_func:
 236         kfree(f_ffs[0]);
 237         return ret;
 238 }
 239 module_init(gfs_init);
 240
 241 static void __exit gfs_exit(void)
 242 {
 243         int i;
 244
 245         ENTER();
 246
 247         if (gfs_registered)
 248                 usb_composite_unregister(&gfs_driver);
 249         gfs_registered = false;
 250
 251         kfree(f_ffs[0]);
 252
 253         for (i = 0; i < func_num; i++)
 254                 usb_put_function_instance(fi_ffs[i]);
 255
 256         kfree(fi_ffs);
 257 }
 258 module_exit(gfs_exit);
 259
 260 static void *functionfs_acquire_dev(struct ffs_dev *dev)
 261 {
 262         if (!try_module_get(THIS_MODULE))
 263                 return ERR_PTR(-ENOENT);
 264
 265         return NULL;
 266 }
 267
 268 static void functionfs_release_dev(struct ffs_dev *dev)
 269 {
 270         module_put(THIS_MODULE);
 271 }
 272
 273 /*
 274  * The caller of this function takes ffs_lock
 275  */
 276 static int functionfs_ready_callback(struct ffs_data *ffs)
 277 {
 278         int ret = 0;
 279
 280         if (--missing_funcs)
 281                 return 0;
 282
 283         if (gfs_registered)
 284                 return -EBUSY;
 285
 286         gfs_registered = true;
 287
 288         ret = usb_composite_probe(&gfs_driver);
 289         if (unlikely(ret < 0)) {
 290                 ++missing_funcs;
 291                 gfs_registered = false;
 292         }
 293
 294         return ret;
 295 }
 296
 297 /*
 298  * The caller of this function takes ffs_lock
 299  */
 300 static void functionfs_closed_callback(struct ffs_data *ffs)
 301 {
 302         missing_funcs++;
 303
 304         if (gfs_registered)
 305                 usb_composite_unregister(&gfs_driver);
 306         gfs_registered = false;
 307 }
 308
 309 /*
 310  * It is assumed that gfs_bind is called from a context where ffs_lock is held
 311  */
 312 static int gfs_bind(struct usb_composite_dev *cdev)
 313 {
 314 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 315         struct net_device *net;
 316 #endif
 317         int ret, i;
 318
 319         ENTER();
 320
 321         if (missing_funcs)
 322                 return -ENODEV;
 323 #if defined CONFIG_USB_FUNCTIONFS_ETH
 324         if (can_support_ecm(cdev->gadget)) {
 325                 struct f_ecm_opts *ecm_opts;
 326
 327                 fi_ecm = usb_get_function_instance("ecm");
 328                 if (IS_ERR(fi_ecm))
 329                         return PTR_ERR(fi_ecm);
 330                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 331                 net = ecm_opts->net;
 332         } else {
 333                 struct f_gether_opts *geth_opts;
 334
 335                 fi_geth = usb_get_function_instance("geth");
 336                 if (IS_ERR(fi_geth))
 337                         return PTR_ERR(fi_geth);
 338                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 339                                          func_inst);
 340                 net = geth_opts->net;
 341         }
 342 #endif
 343
 344 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 345         {
 346                 fi_rndis = usb_get_function_instance("rndis");
 347                 if (IS_ERR(fi_rndis)) {
 348                         ret = PTR_ERR(fi_rndis);
 349                         goto error;
 350                 }
 351 #ifndef CONFIG_USB_FUNCTIONFS_ETH
 352                 net = container_of(fi_rndis, struct f_rndis_opts,
 353                                    func_inst)->net;
 354 #endif
 355         }
 356 #endif
 357
 358 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 359         gether_set_qmult(net, qmult);
 360         if (!gether_set_host_addr(net, host_addr))
 361                 pr_info("using host ethernet address: %s", host_addr);
 362         if (!gether_set_dev_addr(net, dev_addr))
 363                 pr_info("using self ethernet address: %s", dev_addr);
 364 #endif
 365
 366 #if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
 367         gether_set_gadget(net, cdev->gadget);
 368         ret = gether_register_netdev(net);
 369         if (ret)
 370                 goto error_rndis;
 371
 372         if (can_support_ecm(cdev->gadget)) {
 373                 struct f_ecm_opts *ecm_opts;
 374
 375                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 376                 ecm_opts->bound = true;
 377         } else {
 378                 struct f_gether_opts *geth_opts;
 379
 380                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 381                                          func_inst);
 382                 geth_opts->bound = true;
 383         }
 384
 385         rndis_borrow_net(fi_rndis, net);
 386 #endif
 387
 388         /* TODO: gstrings_attach? */
 389         ret = usb_string_ids_tab(cdev, gfs_strings);
 390         if (unlikely(ret < 0))
 391                 goto error_rndis;
 392         gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 393
 394         if (gadget_is_otg(cdev->gadget) && !gfs_otg_desc[0]) {
 395                 struct usb_descriptor_header *usb_desc;
 396
 397                 usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
 398                 if (!usb_desc)
 399                         goto error_rndis;
 400                 usb_otg_descriptor_init(cdev->gadget, usb_desc);
 401                 gfs_otg_desc[0] = usb_desc;
 402                 gfs_otg_desc[1] = NULL;
 403         }
 404
 405         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 406                 struct gfs_configuration *c = gfs_configurations + i;
 407                 int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
 408
 409                 c->c.label                      = gfs_strings[sid].s;
 410                 c->c.iConfiguration             = gfs_strings[sid].id;
 411                 c->c.bConfigurationValue        = 1 + i;
 412                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 413
 414                 c->num = i;
 415
 416                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 417                 if (unlikely(ret < 0))
 418                         goto error_unbind;
 419         }
 420         usb_composite_overwrite_options(cdev, &coverwrite);
 421         return 0;
 422
 423 /* TODO */
 424 error_unbind:
 425         kfree(gfs_otg_desc[0]);
 426         gfs_otg_desc[0] = NULL;
 427 error_rndis:
 428 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 429         usb_put_function_instance(fi_rndis);
 430 error:
 431 #endif
 432 #if defined CONFIG_USB_FUNCTIONFS_ETH
 433         if (can_support_ecm(cdev->gadget))
 434                 usb_put_function_instance(fi_ecm);
 435         else
 436                 usb_put_function_instance(fi_geth);
 437 #endif
 438         return ret;
 439 }
 440
 441 /*
 442  * It is assumed that gfs_unbind is called from a context where ffs_lock is held
 443  */
 444 static int gfs_unbind(struct usb_composite_dev *cdev)
 445 {
 446         int i;
 447
 448         ENTER();
 449
 450
 451 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 452         usb_put_function(f_rndis);
 453         usb_put_function_instance(fi_rndis);
 454 #endif
 455
 456 #if defined CONFIG_USB_FUNCTIONFS_ETH
 457         if (can_support_ecm(cdev->gadget)) {
 458                 usb_put_function(f_ecm);
 459                 usb_put_function_instance(fi_ecm);
 460         } else {
 461                 usb_put_function(f_geth);
 462                 usb_put_function_instance(fi_geth);
 463         }
 464 #endif
 465         for (i = 0; i < N_CONF * func_num; ++i)
 466                 usb_put_function(*(f_ffs[0] + i));
 467
 468         kfree(gfs_otg_desc[0]);
 469         gfs_otg_desc[0] = NULL;
 470
 471         return 0;
 472 }
 473
 474 /*
 475  * It is assumed that gfs_do_config is called from a context where
 476  * ffs_lock is held
 477  */
 478 static int gfs_do_config(struct usb_configuration *c)
 479 {
 480         struct gfs_configuration *gc =
 481                 container_of(c, struct gfs_configuration, c);
 482         int i;
 483         int ret;
 484
 485         if (missing_funcs)
 486                 return -ENODEV;
 487
 488         if (gadget_is_otg(c->cdev->gadget)) {
 489                 c->descriptors = gfs_otg_desc;
 490                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 491         }
 492
 493         if (gc->eth) {
 494                 ret = gc->eth(c);
 495                 if (unlikely(ret < 0))
 496                         return ret;
 497         }
 498
 499         for (i = 0; i < func_num; i++) {
 500                 f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
 501                 if (IS_ERR(f_ffs[gc->num][i])) {
 502                         ret = PTR_ERR(f_ffs[gc->num][i]);
 503                         goto error;
 504                 }
 505                 ret = usb_add_function(c, f_ffs[gc->num][i]);
 506                 if (ret < 0) {
 507                         usb_put_function(f_ffs[gc->num][i]);
 508                         goto error;
 509                 }
 510         }
 511
 512         /*
 513          * After previous do_configs there may be some invalid
 514          * pointers in c->interface array.  This happens every time
 515          * a user space function with fewer interfaces than a user
 516          * space function that was run before the new one is run.  The
 517          * compasit's set_config() assumes that if there is no more
 518          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 519          * then there is a NULL pointer after the last interface in
 520          * c->interface array.  We need to make sure this is true.
 521          */
 522         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 523                 c->interface[c->next_interface_id] = NULL;
 524
 525         return 0;
 526 error:
 527         while (--i >= 0) {
 528                 if (!IS_ERR(f_ffs[gc->num][i]))
 529                         usb_remove_function(c, f_ffs[gc->num][i]);
 530                 usb_put_function(f_ffs[gc->num][i]);
 531         }
 532         return ret;
 533 }
 534
 535 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 536
 537 static int eth_bind_config(struct usb_configuration *c)
 538 {
 539         int status = 0;
 540
 541         if (can_support_ecm(c->cdev->gadget)) {
 542                 f_ecm = usb_get_function(fi_ecm);
 543                 if (IS_ERR(f_ecm))
 544                         return PTR_ERR(f_ecm);
 545
 546                 status = usb_add_function(c, f_ecm);
 547                 if (status < 0)
 548                         usb_put_function(f_ecm);
 549
 550         } else {
 551                 f_geth = usb_get_function(fi_geth);
 552                 if (IS_ERR(f_geth))
 553                         return PTR_ERR(f_geth);
 554
 555                 status = usb_add_function(c, f_geth);
 556                 if (status < 0)
 557                         usb_put_function(f_geth);
 558         }
 559         return status;
 560 }
 561
 562 #endif
 563
 564 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 565
 566 static int bind_rndis_config(struct usb_configuration *c)
 567 {
 568         int status = 0;
 569
 570         f_rndis = usb_get_function(fi_rndis);
 571         if (IS_ERR(f_rndis))
 572                 return PTR_ERR(f_rndis);
 573
 574         status = usb_add_function(c, f_rndis);
 575         if (status < 0)
 576                 usb_put_function(f_rndis);
 577
 578         return status;
 579 }
 580
 581 #endif