drivers/usb/gadget/g_ffs.c

   1 /*
   2  * g_ffs.c -- user mode file system API for USB composite function controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <mina86@mina86.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #define pr_fmt(fmt) "g_ffs: " fmt
  14
  15 #include <linux/module.h>
  16
  17 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
  18 #include <linux/netdevice.h>
  19
  20 #  if defined USB_ETH_RNDIS
  21 #    undef USB_ETH_RNDIS
  22 #  endif
  23 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  24 #    define USB_ETH_RNDIS y
  25 #  endif
  26
  27 #  include "u_ecm.h"
  28 #  include "u_gether.h"
  29 #  ifdef USB_ETH_RNDIS
  30 #    include "u_rndis.h"
  31 #    include "rndis.h"
  32 #  endif
  33 #  include "u_ether.h"
  34
  35 USB_ETHERNET_MODULE_PARAMETERS();
  36
  37 #  ifdef CONFIG_USB_FUNCTIONFS_ETH
  38 static int eth_bind_config(struct usb_configuration *c);
  39 static struct usb_function_instance *fi_ecm;
  40 static struct usb_function *f_ecm;
  41 static struct usb_function_instance *fi_geth;
  42 static struct usb_function *f_geth;
  43 #  endif
  44 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  45 static int bind_rndis_config(struct usb_configuration *c);
  46 static struct usb_function_instance *fi_rndis;
  47 static struct usb_function *f_rndis;
  48 #  endif
  49 #endif
  50
  51 #include "u_fs.h"
  52
  53 #define DRIVER_NAME     "g_ffs"
  54 #define DRIVER_DESC     "USB Function Filesystem"
  55 #define DRIVER_VERSION  "24 Aug 2004"
  56
  57 MODULE_DESCRIPTION(DRIVER_DESC);
  58 MODULE_AUTHOR("Michal Nazarewicz");
  59 MODULE_LICENSE("GPL");
  60
  61 #define GFS_VENDOR_ID   0x1d6b  /* Linux Foundation */
  62 #define GFS_PRODUCT_ID  0x0105  /* FunctionFS Gadget */
  63
  64 #define GFS_MAX_DEVS    10
  65
  66 USB_GADGET_COMPOSITE_OPTIONS();
  67
  68 static struct usb_device_descriptor gfs_dev_desc = {
  69         .bLength                = sizeof gfs_dev_desc,
  70         .bDescriptorType        = USB_DT_DEVICE,
  71
  72         .bcdUSB                 = cpu_to_le16(0x0200),
  73         .bDeviceClass           = USB_CLASS_PER_INTERFACE,
  74
  75         .idVendor               = cpu_to_le16(GFS_VENDOR_ID),
  76         .idProduct              = cpu_to_le16(GFS_PRODUCT_ID),
  77 };
  78
  79 static char *func_names[GFS_MAX_DEVS];
  80 static unsigned int func_num;
  81
  82 module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
  83 MODULE_PARM_DESC(bDeviceClass, "USB Device class");
  84 module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
  85 MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
  86 module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
  87 MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
  88 module_param_array_named(functions, func_names, charp, &func_num, 0);
  89 MODULE_PARM_DESC(functions, "USB Functions list");
  90
  91 static const struct usb_descriptor_header *gfs_otg_desc[] = {
  92         (const struct usb_descriptor_header *)
  93         &(const struct usb_otg_descriptor) {
  94                 .bLength                = sizeof(struct usb_otg_descriptor),
  95                 .bDescriptorType        = USB_DT_OTG,
  96
  97                 /*
  98                  * REVISIT SRP-only hardware is possible, although
  99                  * it would not be called "OTG" ...
 100                  */
 101                 .bmAttributes           = USB_OTG_SRP | USB_OTG_HNP,
 102         },
 103
 104         NULL
 105 };
 106
 107 /* String IDs are assigned dynamically */
 108 static struct usb_string gfs_strings[] = {
 109         [USB_GADGET_MANUFACTURER_IDX].s = "",
 110         [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
 111         [USB_GADGET_SERIAL_IDX].s = "",
 112 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 113         { .s = "FunctionFS + RNDIS" },
 114 #endif
 115 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 116         { .s = "FunctionFS + ECM" },
 117 #endif
 118 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 119         { .s = "FunctionFS" },
 120 #endif
 121         {  } /* end of list */
 122 };
 123
 124 static struct usb_gadget_strings *gfs_dev_strings[] = {
 125         &(struct usb_gadget_strings) {
 126                 .language       = 0x0409,       /* en-us */
 127                 .strings        = gfs_strings,
 128         },
 129         NULL,
 130 };
 131
 132 struct gfs_configuration {
 133         struct usb_configuration c;
 134         int (*eth)(struct usb_configuration *c);
 135         int num;
 136 } gfs_configurations[] = {
 137 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 138         {
 139                 .eth            = bind_rndis_config,
 140         },
 141 #endif
 142
 143 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 144         {
 145                 .eth            = eth_bind_config,
 146         },
 147 #endif
 148
 149 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 150         {
 151         },
 152 #endif
 153 };
 154
 155 static void *functionfs_acquire_dev(struct ffs_dev *dev);
 156 static void functionfs_release_dev(struct ffs_dev *dev);
 157 static int functionfs_ready_callback(struct ffs_data *ffs);
 158 static void functionfs_closed_callback(struct ffs_data *ffs);
 159 static int gfs_bind(struct usb_composite_dev *cdev);
 160 static int gfs_unbind(struct usb_composite_dev *cdev);
 161 static int gfs_do_config(struct usb_configuration *c);
 162
 163
 164 static __refdata struct usb_composite_driver gfs_driver = {
 165         .name           = DRIVER_NAME,
 166         .dev            = &gfs_dev_desc,
 167         .strings        = gfs_dev_strings,
 168         .max_speed      = USB_SPEED_HIGH,
 169         .bind           = gfs_bind,
 170         .unbind         = gfs_unbind,
 171 };
 172
 173 static unsigned int missing_funcs;
 174 static bool gfs_registered;
 175 static bool gfs_single_func;
 176 static struct usb_function_instance **fi_ffs;
 177 static struct usb_function **f_ffs[] = {
 178 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 179         NULL,
 180 #endif
 181
 182 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 183         NULL,
 184 #endif
 185
 186 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 187         NULL,
 188 #endif
 189 };
 190
 191 #define N_CONF ARRAY_SIZE(f_ffs)
 192
 193 static int __init gfs_init(void)
 194 {
 195         struct f_fs_opts *opts;
 196         int i;
 197         int ret = 0;
 198
 199         ENTER();
 200
 201         if (func_num < 2) {
 202                 gfs_single_func = true;
 203                 func_num = 1;
 204         }
 205
 206         /*
 207          * Allocate in one chunk for easier maintenance
 208          */
 209         f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
 210         if (!f_ffs[0]) {
 211                 ret = -ENOMEM;
 212                 goto no_func;
 213         }
 214         for (i = 1; i < N_CONF; ++i)
 215                 f_ffs[i] = f_ffs[0] + i * func_num;
 216
 217         fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
 218         if (!fi_ffs) {
 219                 ret = -ENOMEM;
 220                 goto no_func;
 221         }
 222
 223         for (i = 0; i < func_num; i++) {
 224                 fi_ffs[i] = usb_get_function_instance("ffs");
 225                 if (IS_ERR(fi_ffs[i])) {
 226                         ret = PTR_ERR(fi_ffs[i]);
 227                         --i;
 228                         goto no_dev;
 229                 }
 230                 opts = to_f_fs_opts(fi_ffs[i]);
 231                 if (gfs_single_func)
 232                         ret = ffs_single_dev(opts->dev);
 233                 else
 234                         ret = ffs_name_dev(opts->dev, func_names[i]);
 235                 if (ret)
 236                         goto no_dev;
 237                 opts->dev->ffs_ready_callback = functionfs_ready_callback;
 238                 opts->dev->ffs_closed_callback = functionfs_closed_callback;
 239                 opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
 240                 opts->dev->ffs_release_dev_callback = functionfs_release_dev;
 241                 opts->no_configfs = true;
 242         }
 243
 244         missing_funcs = func_num;
 245
 246         return 0;
 247 no_dev:
 248         while (i >= 0)
 249                 usb_put_function_instance(fi_ffs[i--]);
 250         kfree(fi_ffs);
 251 no_func:
 252         kfree(f_ffs[0]);
 253         return ret;
 254 }
 255 module_init(gfs_init);
 256
 257 static void __exit gfs_exit(void)
 258 {
 259         int i;
 260
 261         ENTER();
 262
 263         if (gfs_registered)
 264                 usb_composite_unregister(&gfs_driver);
 265         gfs_registered = false;
 266
 267         kfree(f_ffs[0]);
 268
 269         for (i = 0; i < func_num; i++)
 270                 usb_put_function_instance(fi_ffs[i]);
 271
 272         kfree(fi_ffs);
 273 }
 274 module_exit(gfs_exit);
 275
 276 static void *functionfs_acquire_dev(struct ffs_dev *dev)
 277 {
 278         if (!try_module_get(THIS_MODULE))
 279                 return ERR_PTR(-ENODEV);
 280
 281         return 0;
 282 }
 283
 284 static void functionfs_release_dev(struct ffs_dev *dev)
 285 {
 286         module_put(THIS_MODULE);
 287 }
 288
 289 /*
 290  * The caller of this function takes ffs_lock
 291  */
 292 static int functionfs_ready_callback(struct ffs_data *ffs)
 293 {
 294         int ret = 0;
 295
 296         if (--missing_funcs)
 297                 return 0;
 298
 299         if (gfs_registered)
 300                 return -EBUSY;
 301
 302         gfs_registered = true;
 303
 304         ret = usb_composite_probe(&gfs_driver);
 305         if (unlikely(ret < 0))
 306                 gfs_registered = false;
 307
 308         return ret;
 309 }
 310
 311 /*
 312  * The caller of this function takes ffs_lock
 313  */
 314 static void functionfs_closed_callback(struct ffs_data *ffs)
 315 {
 316         missing_funcs++;
 317
 318         if (gfs_registered)
 319                 usb_composite_unregister(&gfs_driver);
 320         gfs_registered = false;
 321 }
 322
 323 /*
 324  * It is assumed that gfs_bind is called from a context where ffs_lock is held
 325  */
 326 static int gfs_bind(struct usb_composite_dev *cdev)
 327 {
 328 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 329         struct net_device *net;
 330 #endif
 331         int ret, i;
 332
 333         ENTER();
 334
 335         if (missing_funcs)
 336                 return -ENODEV;
 337 #if defined CONFIG_USB_FUNCTIONFS_ETH
 338         if (can_support_ecm(cdev->gadget)) {
 339                 struct f_ecm_opts *ecm_opts;
 340
 341                 fi_ecm = usb_get_function_instance("ecm");
 342                 if (IS_ERR(fi_ecm))
 343                         return PTR_ERR(fi_ecm);
 344                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 345                 net = ecm_opts->net;
 346         } else {
 347                 struct f_gether_opts *geth_opts;
 348
 349                 fi_geth = usb_get_function_instance("geth");
 350                 if (IS_ERR(fi_geth))
 351                         return PTR_ERR(fi_geth);
 352                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 353                                          func_inst);
 354                 net = geth_opts->net;
 355         }
 356 #endif
 357
 358 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 359         {
 360                 struct f_rndis_opts *rndis_opts;
 361
 362                 fi_rndis = usb_get_function_instance("rndis");
 363                 if (IS_ERR(fi_rndis)) {
 364                         ret = PTR_ERR(fi_rndis);
 365                         goto error;
 366                 }
 367                 rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
 368                                           func_inst);
 369 #ifndef CONFIG_USB_FUNCTIONFS_ETH
 370                 net = rndis_opts->net;
 371 #endif
 372         }
 373 #endif
 374
 375 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 376         gether_set_qmult(net, qmult);
 377         if (!gether_set_host_addr(net, host_addr))
 378                 pr_info("using host ethernet address: %s", host_addr);
 379         if (!gether_set_dev_addr(net, dev_addr))
 380                 pr_info("using self ethernet address: %s", dev_addr);
 381 #endif
 382
 383 #if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
 384         gether_set_gadget(net, cdev->gadget);
 385         ret = gether_register_netdev(net);
 386         if (ret)
 387                 goto error_rndis;
 388
 389         if (can_support_ecm(cdev->gadget)) {
 390                 struct f_ecm_opts *ecm_opts;
 391
 392                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 393                 ecm_opts->bound = true;
 394         } else {
 395                 struct f_gether_opts *geth_opts;
 396
 397                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 398                                          func_inst);
 399                 geth_opts->bound = true;
 400         }
 401
 402         rndis_borrow_net(fi_rndis, net);
 403 #endif
 404
 405         /* TODO: gstrings_attach? */
 406         ret = usb_string_ids_tab(cdev, gfs_strings);
 407         if (unlikely(ret < 0))
 408                 goto error_rndis;
 409         gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 410
 411         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 412                 struct gfs_configuration *c = gfs_configurations + i;
 413                 int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
 414
 415                 c->c.label                      = gfs_strings[sid].s;
 416                 c->c.iConfiguration             = gfs_strings[sid].id;
 417                 c->c.bConfigurationValue        = 1 + i;
 418                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 419
 420                 c->num = i;
 421
 422                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 423                 if (unlikely(ret < 0))
 424                         goto error_unbind;
 425         }
 426         usb_composite_overwrite_options(cdev, &coverwrite);
 427         return 0;
 428
 429 /* TODO */
 430 error_unbind:
 431 error_rndis:
 432 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 433         usb_put_function_instance(fi_rndis);
 434 error:
 435 #endif
 436 #if defined CONFIG_USB_FUNCTIONFS_ETH
 437         if (can_support_ecm(cdev->gadget))
 438                 usb_put_function_instance(fi_ecm);
 439         else
 440                 usb_put_function_instance(fi_geth);
 441 #endif
 442         return ret;
 443 }
 444
 445 /*
 446  * It is assumed that gfs_unbind is called from a context where ffs_lock is held
 447  */
 448 static int gfs_unbind(struct usb_composite_dev *cdev)
 449 {
 450         int i;
 451
 452         ENTER();
 453
 454
 455 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 456         usb_put_function(f_rndis);
 457         usb_put_function_instance(fi_rndis);
 458 #endif
 459
 460 #if defined CONFIG_USB_FUNCTIONFS_ETH
 461         if (can_support_ecm(cdev->gadget)) {
 462                 usb_put_function(f_ecm);
 463                 usb_put_function_instance(fi_ecm);
 464         } else {
 465                 usb_put_function(f_geth);
 466                 usb_put_function_instance(fi_geth);
 467         }
 468 #endif
 469         for (i = 0; i < N_CONF * func_num; ++i)
 470                 usb_put_function(*(f_ffs[0] + i));
 471
 472         return 0;
 473 }
 474
 475 /*
 476  * It is assumed that gfs_do_config is called from a context where
 477  * ffs_lock is held
 478  */
 479 static int gfs_do_config(struct usb_configuration *c)
 480 {
 481         struct gfs_configuration *gc =
 482                 container_of(c, struct gfs_configuration, c);
 483         int i;
 484         int ret;
 485
 486         if (missing_funcs)
 487                 return -ENODEV;
 488
 489         if (gadget_is_otg(c->cdev->gadget)) {
 490                 c->descriptors = gfs_otg_desc;
 491                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 492         }
 493
 494         if (gc->eth) {
 495                 ret = gc->eth(c);
 496                 if (unlikely(ret < 0))
 497                         return ret;
 498         }
 499
 500         for (i = 0; i < func_num; i++) {
 501                 f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
 502                 if (IS_ERR(f_ffs[gc->num][i])) {
 503                         ret = PTR_ERR(f_ffs[gc->num][i]);
 504                         goto error;
 505                 }
 506                 ret = usb_add_function(c, f_ffs[gc->num][i]);
 507                 if (ret < 0) {
 508                         usb_put_function(f_ffs[gc->num][i]);
 509                         goto error;
 510                 }
 511         }
 512
 513         /*
 514          * After previous do_configs there may be some invalid
 515          * pointers in c->interface array.  This happens every time
 516          * a user space function with fewer interfaces than a user
 517          * space function that was run before the new one is run.  The
 518          * compasit's set_config() assumes that if there is no more
 519          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 520          * then there is a NULL pointer after the last interface in
 521          * c->interface array.  We need to make sure this is true.
 522          */
 523         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 524                 c->interface[c->next_interface_id] = NULL;
 525
 526         return 0;
 527 error:
 528         while (--i >= 0) {
 529                 if (!IS_ERR(f_ffs[gc->num][i]))
 530                         usb_remove_function(c, f_ffs[gc->num][i]);
 531                 usb_put_function(f_ffs[gc->num][i]);
 532         }
 533         return ret;
 534 }
 535
 536 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 537
 538 static int eth_bind_config(struct usb_configuration *c)
 539 {
 540         int status = 0;
 541
 542         if (can_support_ecm(c->cdev->gadget)) {
 543                 f_ecm = usb_get_function(fi_ecm);
 544                 if (IS_ERR(f_ecm))
 545                         return PTR_ERR(f_ecm);
 546
 547                 status = usb_add_function(c, f_ecm);
 548                 if (status < 0)
 549                         usb_put_function(f_ecm);
 550
 551         } else {
 552                 f_geth = usb_get_function(fi_geth);
 553                 if (IS_ERR(f_geth))
 554                         return PTR_ERR(f_geth);
 555
 556                 status = usb_add_function(c, f_geth);
 557                 if (status < 0)
 558                         usb_put_function(f_geth);
 559         }
 560         return status;
 561 }
 562
 563 #endif
 564
 565 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 566
 567 static int bind_rndis_config(struct usb_configuration *c)
 568 {
 569         int status = 0;
 570
 571         f_rndis = usb_get_function(fi_rndis);
 572         if (IS_ERR(f_rndis))
 573                 return PTR_ERR(f_rndis);
 574
 575         status = usb_add_function(c, f_rndis);
 576         if (status < 0)
 577                 usb_put_function(f_rndis);
 578
 579         return status;
 580 }
 581
 582 #endif