drivers/usb/gadget/legacy/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 };
 137
 138 static struct gfs_configuration gfs_configurations[] = {
 139 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 140         {
 141                 .eth            = bind_rndis_config,
 142         },
 143 #endif
 144
 145 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 146         {
 147                 .eth            = eth_bind_config,
 148         },
 149 #endif
 150
 151 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 152         {
 153         },
 154 #endif
 155 };
 156
 157 static void *functionfs_acquire_dev(struct ffs_dev *dev);
 158 static void functionfs_release_dev(struct ffs_dev *dev);
 159 static int functionfs_ready_callback(struct ffs_data *ffs);
 160 static void functionfs_closed_callback(struct ffs_data *ffs);
 161 static int gfs_bind(struct usb_composite_dev *cdev);
 162 static int gfs_unbind(struct usb_composite_dev *cdev);
 163 static int gfs_do_config(struct usb_configuration *c);
 164
 165
 166 static struct usb_composite_driver gfs_driver = {
 167         .name           = DRIVER_NAME,
 168         .dev            = &gfs_dev_desc,
 169         .strings        = gfs_dev_strings,
 170         .max_speed      = USB_SPEED_HIGH,
 171         .bind           = gfs_bind,
 172         .unbind         = gfs_unbind,
 173 };
 174
 175 static unsigned int missing_funcs;
 176 static bool gfs_registered;
 177 static bool gfs_single_func;
 178 static struct usb_function_instance **fi_ffs;
 179 static struct usb_function **f_ffs[] = {
 180 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 181         NULL,
 182 #endif
 183
 184 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 185         NULL,
 186 #endif
 187
 188 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 189         NULL,
 190 #endif
 191 };
 192
 193 #define N_CONF ARRAY_SIZE(f_ffs)
 194
 195 static int __init gfs_init(void)
 196 {
 197         struct f_fs_opts *opts;
 198         int i;
 199         int ret = 0;
 200
 201         ENTER();
 202
 203         if (func_num < 2) {
 204                 gfs_single_func = true;
 205                 func_num = 1;
 206         }
 207
 208         /*
 209          * Allocate in one chunk for easier maintenance
 210          */
 211         f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
 212         if (!f_ffs[0]) {
 213                 ret = -ENOMEM;
 214                 goto no_func;
 215         }
 216         for (i = 1; i < N_CONF; ++i)
 217                 f_ffs[i] = f_ffs[0] + i * func_num;
 218
 219         fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
 220         if (!fi_ffs) {
 221                 ret = -ENOMEM;
 222                 goto no_func;
 223         }
 224
 225         for (i = 0; i < func_num; i++) {
 226                 fi_ffs[i] = usb_get_function_instance("ffs");
 227                 if (IS_ERR(fi_ffs[i])) {
 228                         ret = PTR_ERR(fi_ffs[i]);
 229                         --i;
 230                         goto no_dev;
 231                 }
 232                 opts = to_f_fs_opts(fi_ffs[i]);
 233                 if (gfs_single_func)
 234                         ret = ffs_single_dev(opts->dev);
 235                 else
 236                         ret = ffs_name_dev(opts->dev, func_names[i]);
 237                 if (ret)
 238                         goto no_dev;
 239                 opts->dev->ffs_ready_callback = functionfs_ready_callback;
 240                 opts->dev->ffs_closed_callback = functionfs_closed_callback;
 241                 opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
 242                 opts->dev->ffs_release_dev_callback = functionfs_release_dev;
 243                 opts->no_configfs = true;
 244         }
 245
 246         missing_funcs = func_num;
 247
 248         return 0;
 249 no_dev:
 250         while (i >= 0)
 251                 usb_put_function_instance(fi_ffs[i--]);
 252         kfree(fi_ffs);
 253 no_func:
 254         kfree(f_ffs[0]);
 255         return ret;
 256 }
 257 module_init(gfs_init);
 258
 259 static void __exit gfs_exit(void)
 260 {
 261         int i;
 262
 263         ENTER();
 264
 265         if (gfs_registered)
 266                 usb_composite_unregister(&gfs_driver);
 267         gfs_registered = false;
 268
 269         kfree(f_ffs[0]);
 270
 271         for (i = 0; i < func_num; i++)
 272                 usb_put_function_instance(fi_ffs[i]);
 273
 274         kfree(fi_ffs);
 275 }
 276 module_exit(gfs_exit);
 277
 278 static void *functionfs_acquire_dev(struct ffs_dev *dev)
 279 {
 280         if (!try_module_get(THIS_MODULE))
 281                 return ERR_PTR(-ENOENT);
 282
 283         return NULL;
 284 }
 285
 286 static void functionfs_release_dev(struct ffs_dev *dev)
 287 {
 288         module_put(THIS_MODULE);
 289 }
 290
 291 /*
 292  * The caller of this function takes ffs_lock
 293  */
 294 static int functionfs_ready_callback(struct ffs_data *ffs)
 295 {
 296         int ret = 0;
 297
 298         if (--missing_funcs)
 299                 return 0;
 300
 301         if (gfs_registered)
 302                 return -EBUSY;
 303
 304         gfs_registered = true;
 305
 306         ret = usb_composite_probe(&gfs_driver);
 307         if (unlikely(ret < 0)) {
 308                 ++missing_funcs;
 309                 gfs_registered = false;
 310         }
 311
 312         return ret;
 313 }
 314
 315 /*
 316  * The caller of this function takes ffs_lock
 317  */
 318 static void functionfs_closed_callback(struct ffs_data *ffs)
 319 {
 320         missing_funcs++;
 321
 322         if (gfs_registered)
 323                 usb_composite_unregister(&gfs_driver);
 324         gfs_registered = false;
 325 }
 326
 327 /*
 328  * It is assumed that gfs_bind is called from a context where ffs_lock is held
 329  */
 330 static int gfs_bind(struct usb_composite_dev *cdev)
 331 {
 332 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 333         struct net_device *net;
 334 #endif
 335         int ret, i;
 336
 337         ENTER();
 338
 339         if (missing_funcs)
 340                 return -ENODEV;
 341 #if defined CONFIG_USB_FUNCTIONFS_ETH
 342         if (can_support_ecm(cdev->gadget)) {
 343                 struct f_ecm_opts *ecm_opts;
 344
 345                 fi_ecm = usb_get_function_instance("ecm");
 346                 if (IS_ERR(fi_ecm))
 347                         return PTR_ERR(fi_ecm);
 348                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 349                 net = ecm_opts->net;
 350         } else {
 351                 struct f_gether_opts *geth_opts;
 352
 353                 fi_geth = usb_get_function_instance("geth");
 354                 if (IS_ERR(fi_geth))
 355                         return PTR_ERR(fi_geth);
 356                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 357                                          func_inst);
 358                 net = geth_opts->net;
 359         }
 360 #endif
 361
 362 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 363         {
 364                 struct f_rndis_opts *rndis_opts;
 365
 366                 fi_rndis = usb_get_function_instance("rndis");
 367                 if (IS_ERR(fi_rndis)) {
 368                         ret = PTR_ERR(fi_rndis);
 369                         goto error;
 370                 }
 371                 rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
 372                                           func_inst);
 373 #ifndef CONFIG_USB_FUNCTIONFS_ETH
 374                 net = rndis_opts->net;
 375 #endif
 376         }
 377 #endif
 378
 379 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 380         gether_set_qmult(net, qmult);
 381         if (!gether_set_host_addr(net, host_addr))
 382                 pr_info("using host ethernet address: %s", host_addr);
 383         if (!gether_set_dev_addr(net, dev_addr))
 384                 pr_info("using self ethernet address: %s", dev_addr);
 385 #endif
 386
 387 #if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
 388         gether_set_gadget(net, cdev->gadget);
 389         ret = gether_register_netdev(net);
 390         if (ret)
 391                 goto error_rndis;
 392
 393         if (can_support_ecm(cdev->gadget)) {
 394                 struct f_ecm_opts *ecm_opts;
 395
 396                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 397                 ecm_opts->bound = true;
 398         } else {
 399                 struct f_gether_opts *geth_opts;
 400
 401                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 402                                          func_inst);
 403                 geth_opts->bound = true;
 404         }
 405
 406         rndis_borrow_net(fi_rndis, net);
 407 #endif
 408
 409         /* TODO: gstrings_attach? */
 410         ret = usb_string_ids_tab(cdev, gfs_strings);
 411         if (unlikely(ret < 0))
 412                 goto error_rndis;
 413         gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 414
 415         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 416                 struct gfs_configuration *c = gfs_configurations + i;
 417                 int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
 418
 419                 c->c.label                      = gfs_strings[sid].s;
 420                 c->c.iConfiguration             = gfs_strings[sid].id;
 421                 c->c.bConfigurationValue        = 1 + i;
 422                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 423
 424                 c->num = i;
 425
 426                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 427                 if (unlikely(ret < 0))
 428                         goto error_unbind;
 429         }
 430         usb_composite_overwrite_options(cdev, &coverwrite);
 431         return 0;
 432
 433 /* TODO */
 434 error_unbind:
 435 error_rndis:
 436 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 437         usb_put_function_instance(fi_rndis);
 438 error:
 439 #endif
 440 #if defined CONFIG_USB_FUNCTIONFS_ETH
 441         if (can_support_ecm(cdev->gadget))
 442                 usb_put_function_instance(fi_ecm);
 443         else
 444                 usb_put_function_instance(fi_geth);
 445 #endif
 446         return ret;
 447 }
 448
 449 /*
 450  * It is assumed that gfs_unbind is called from a context where ffs_lock is held
 451  */
 452 static int gfs_unbind(struct usb_composite_dev *cdev)
 453 {
 454         int i;
 455
 456         ENTER();
 457
 458
 459 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 460         usb_put_function(f_rndis);
 461         usb_put_function_instance(fi_rndis);
 462 #endif
 463
 464 #if defined CONFIG_USB_FUNCTIONFS_ETH
 465         if (can_support_ecm(cdev->gadget)) {
 466                 usb_put_function(f_ecm);
 467                 usb_put_function_instance(fi_ecm);
 468         } else {
 469                 usb_put_function(f_geth);
 470                 usb_put_function_instance(fi_geth);
 471         }
 472 #endif
 473         for (i = 0; i < N_CONF * func_num; ++i)
 474                 usb_put_function(*(f_ffs[0] + i));
 475
 476         return 0;
 477 }
 478
 479 /*
 480  * It is assumed that gfs_do_config is called from a context where
 481  * ffs_lock is held
 482  */
 483 static int gfs_do_config(struct usb_configuration *c)
 484 {
 485         struct gfs_configuration *gc =
 486                 container_of(c, struct gfs_configuration, c);
 487         int i;
 488         int ret;
 489
 490         if (missing_funcs)
 491                 return -ENODEV;
 492
 493         if (gadget_is_otg(c->cdev->gadget)) {
 494                 c->descriptors = gfs_otg_desc;
 495                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 496         }
 497
 498         if (gc->eth) {
 499                 ret = gc->eth(c);
 500                 if (unlikely(ret < 0))
 501                         return ret;
 502         }
 503
 504         for (i = 0; i < func_num; i++) {
 505                 f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
 506                 if (IS_ERR(f_ffs[gc->num][i])) {
 507                         ret = PTR_ERR(f_ffs[gc->num][i]);
 508                         goto error;
 509                 }
 510                 ret = usb_add_function(c, f_ffs[gc->num][i]);
 511                 if (ret < 0) {
 512                         usb_put_function(f_ffs[gc->num][i]);
 513                         goto error;
 514                 }
 515         }
 516
 517         /*
 518          * After previous do_configs there may be some invalid
 519          * pointers in c->interface array.  This happens every time
 520          * a user space function with fewer interfaces than a user
 521          * space function that was run before the new one is run.  The
 522          * compasit's set_config() assumes that if there is no more
 523          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 524          * then there is a NULL pointer after the last interface in
 525          * c->interface array.  We need to make sure this is true.
 526          */
 527         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 528                 c->interface[c->next_interface_id] = NULL;
 529
 530         return 0;
 531 error:
 532         while (--i >= 0) {
 533                 if (!IS_ERR(f_ffs[gc->num][i]))
 534                         usb_remove_function(c, f_ffs[gc->num][i]);
 535                 usb_put_function(f_ffs[gc->num][i]);
 536         }
 537         return ret;
 538 }
 539
 540 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 541
 542 static int eth_bind_config(struct usb_configuration *c)
 543 {
 544         int status = 0;
 545
 546         if (can_support_ecm(c->cdev->gadget)) {
 547                 f_ecm = usb_get_function(fi_ecm);
 548                 if (IS_ERR(f_ecm))
 549                         return PTR_ERR(f_ecm);
 550
 551                 status = usb_add_function(c, f_ecm);
 552                 if (status < 0)
 553                         usb_put_function(f_ecm);
 554
 555         } else {
 556                 f_geth = usb_get_function(fi_geth);
 557                 if (IS_ERR(f_geth))
 558                         return PTR_ERR(f_geth);
 559
 560                 status = usb_add_function(c, f_geth);
 561                 if (status < 0)
 562                         usb_put_function(f_geth);
 563         }
 564         return status;
 565 }
 566
 567 #endif
 568
 569 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 570
 571 static int bind_rndis_config(struct usb_configuration *c)
 572 {
 573         int status = 0;
 574
 575         f_rndis = usb_get_function(fi_rndis);
 576         if (IS_ERR(f_rndis))
 577                 return PTR_ERR(f_rndis);
 578
 579         status = usb_add_function(c, f_rndis);
 580         if (status < 0)
 581                 usb_put_function(f_rndis);
 582
 583         return status;
 584 }
 585
 586 #endif