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 __refdata 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                 gfs_registered = false;
 309
 310         return ret;
 311 }
 312
 313 /*
 314  * The caller of this function takes ffs_lock
 315  */
 316 static void functionfs_closed_callback(struct ffs_data *ffs)
 317 {
 318         missing_funcs++;
 319
 320         if (gfs_registered)
 321                 usb_composite_unregister(&gfs_driver);
 322         gfs_registered = false;
 323 }
 324
 325 /*
 326  * It is assumed that gfs_bind is called from a context where ffs_lock is held
 327  */
 328 static int gfs_bind(struct usb_composite_dev *cdev)
 329 {
 330 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 331         struct net_device *net;
 332 #endif
 333         int ret, i;
 334
 335         ENTER();
 336
 337         if (missing_funcs)
 338                 return -ENODEV;
 339 #if defined CONFIG_USB_FUNCTIONFS_ETH
 340         if (can_support_ecm(cdev->gadget)) {
 341                 struct f_ecm_opts *ecm_opts;
 342
 343                 fi_ecm = usb_get_function_instance("ecm");
 344                 if (IS_ERR(fi_ecm))
 345                         return PTR_ERR(fi_ecm);
 346                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 347                 net = ecm_opts->net;
 348         } else {
 349                 struct f_gether_opts *geth_opts;
 350
 351                 fi_geth = usb_get_function_instance("geth");
 352                 if (IS_ERR(fi_geth))
 353                         return PTR_ERR(fi_geth);
 354                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 355                                          func_inst);
 356                 net = geth_opts->net;
 357         }
 358 #endif
 359
 360 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 361         {
 362                 struct f_rndis_opts *rndis_opts;
 363
 364                 fi_rndis = usb_get_function_instance("rndis");
 365                 if (IS_ERR(fi_rndis)) {
 366                         ret = PTR_ERR(fi_rndis);
 367                         goto error;
 368                 }
 369                 rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
 370                                           func_inst);
 371 #ifndef CONFIG_USB_FUNCTIONFS_ETH
 372                 net = rndis_opts->net;
 373 #endif
 374         }
 375 #endif
 376
 377 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 378         gether_set_qmult(net, qmult);
 379         if (!gether_set_host_addr(net, host_addr))
 380                 pr_info("using host ethernet address: %s", host_addr);
 381         if (!gether_set_dev_addr(net, dev_addr))
 382                 pr_info("using self ethernet address: %s", dev_addr);
 383 #endif
 384
 385 #if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
 386         gether_set_gadget(net, cdev->gadget);
 387         ret = gether_register_netdev(net);
 388         if (ret)
 389                 goto error_rndis;
 390
 391         if (can_support_ecm(cdev->gadget)) {
 392                 struct f_ecm_opts *ecm_opts;
 393
 394                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 395                 ecm_opts->bound = true;
 396         } else {
 397                 struct f_gether_opts *geth_opts;
 398
 399                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 400                                          func_inst);
 401                 geth_opts->bound = true;
 402         }
 403
 404         rndis_borrow_net(fi_rndis, net);
 405 #endif
 406
 407         /* TODO: gstrings_attach? */
 408         ret = usb_string_ids_tab(cdev, gfs_strings);
 409         if (unlikely(ret < 0))
 410                 goto error_rndis;
 411         gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 412
 413         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 414                 struct gfs_configuration *c = gfs_configurations + i;
 415                 int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
 416
 417                 c->c.label                      = gfs_strings[sid].s;
 418                 c->c.iConfiguration             = gfs_strings[sid].id;
 419                 c->c.bConfigurationValue        = 1 + i;
 420                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 421
 422                 c->num = i;
 423
 424                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 425                 if (unlikely(ret < 0))
 426                         goto error_unbind;
 427         }
 428         usb_composite_overwrite_options(cdev, &coverwrite);
 429         return 0;
 430
 431 /* TODO */
 432 error_unbind:
 433 error_rndis:
 434 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 435         usb_put_function_instance(fi_rndis);
 436 error:
 437 #endif
 438 #if defined CONFIG_USB_FUNCTIONFS_ETH
 439         if (can_support_ecm(cdev->gadget))
 440                 usb_put_function_instance(fi_ecm);
 441         else
 442                 usb_put_function_instance(fi_geth);
 443 #endif
 444         return ret;
 445 }
 446
 447 /*
 448  * It is assumed that gfs_unbind is called from a context where ffs_lock is held
 449  */
 450 static int gfs_unbind(struct usb_composite_dev *cdev)
 451 {
 452         int i;
 453
 454         ENTER();
 455
 456
 457 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 458         usb_put_function(f_rndis);
 459         usb_put_function_instance(fi_rndis);
 460 #endif
 461
 462 #if defined CONFIG_USB_FUNCTIONFS_ETH
 463         if (can_support_ecm(cdev->gadget)) {
 464                 usb_put_function(f_ecm);
 465                 usb_put_function_instance(fi_ecm);
 466         } else {
 467                 usb_put_function(f_geth);
 468                 usb_put_function_instance(fi_geth);
 469         }
 470 #endif
 471         for (i = 0; i < N_CONF * func_num; ++i)
 472                 usb_put_function(*(f_ffs[0] + i));
 473
 474         return 0;
 475 }
 476
 477 /*
 478  * It is assumed that gfs_do_config is called from a context where
 479  * ffs_lock is held
 480  */
 481 static int gfs_do_config(struct usb_configuration *c)
 482 {
 483         struct gfs_configuration *gc =
 484                 container_of(c, struct gfs_configuration, c);
 485         int i;
 486         int ret;
 487
 488         if (missing_funcs)
 489                 return -ENODEV;
 490
 491         if (gadget_is_otg(c->cdev->gadget)) {
 492                 c->descriptors = gfs_otg_desc;
 493                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 494         }
 495
 496         if (gc->eth) {
 497                 ret = gc->eth(c);
 498                 if (unlikely(ret < 0))
 499                         return ret;
 500         }
 501
 502         for (i = 0; i < func_num; i++) {
 503                 f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
 504                 if (IS_ERR(f_ffs[gc->num][i])) {
 505                         ret = PTR_ERR(f_ffs[gc->num][i]);
 506                         goto error;
 507                 }
 508                 ret = usb_add_function(c, f_ffs[gc->num][i]);
 509                 if (ret < 0) {
 510                         usb_put_function(f_ffs[gc->num][i]);
 511                         goto error;
 512                 }
 513         }
 514
 515         /*
 516          * After previous do_configs there may be some invalid
 517          * pointers in c->interface array.  This happens every time
 518          * a user space function with fewer interfaces than a user
 519          * space function that was run before the new one is run.  The
 520          * compasit's set_config() assumes that if there is no more
 521          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 522          * then there is a NULL pointer after the last interface in
 523          * c->interface array.  We need to make sure this is true.
 524          */
 525         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 526                 c->interface[c->next_interface_id] = NULL;
 527
 528         return 0;
 529 error:
 530         while (--i >= 0) {
 531                 if (!IS_ERR(f_ffs[gc->num][i]))
 532                         usb_remove_function(c, f_ffs[gc->num][i]);
 533                 usb_put_function(f_ffs[gc->num][i]);
 534         }
 535         return ret;
 536 }
 537
 538 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 539
 540 static int eth_bind_config(struct usb_configuration *c)
 541 {
 542         int status = 0;
 543
 544         if (can_support_ecm(c->cdev->gadget)) {
 545                 f_ecm = usb_get_function(fi_ecm);
 546                 if (IS_ERR(f_ecm))
 547                         return PTR_ERR(f_ecm);
 548
 549                 status = usb_add_function(c, f_ecm);
 550                 if (status < 0)
 551                         usb_put_function(f_ecm);
 552
 553         } else {
 554                 f_geth = usb_get_function(fi_geth);
 555                 if (IS_ERR(f_geth))
 556                         return PTR_ERR(f_geth);
 557
 558                 status = usb_add_function(c, f_geth);
 559                 if (status < 0)
 560                         usb_put_function(f_geth);
 561         }
 562         return status;
 563 }
 564
 565 #endif
 566
 567 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 568
 569 static int bind_rndis_config(struct usb_configuration *c)
 570 {
 571         int status = 0;
 572
 573         f_rndis = usb_get_function(fi_rndis);
 574         if (IS_ERR(f_rndis))
 575                 return PTR_ERR(f_rndis);
 576
 577         status = usb_add_function(c, f_rndis);
 578         if (status < 0)
 579                 usb_put_function(f_rndis);
 580
 581         return status;
 582 }
 583
 584 #endif