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  * kbuild is not very cooperative with respect to linking separately
  18  * compiled library objects into one module.  So for now we won't use
  19  * separate compilation ... ensuring init/exit sections work to shrink
  20  * the runtime footprint, and giving us at least some parts of what
  21  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  22  */
  23 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
  24 #  if defined USB_ETH_RNDIS
  25 #    undef USB_ETH_RNDIS
  26 #  endif
  27 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  28 #    define USB_ETH_RNDIS y
  29 #  endif
  30
  31 #define USBF_ECM_INCLUDED
  32 #  include "f_ecm.c"
  33 #define USB_FSUBSET_INCLUDED
  34 #  include "f_subset.c"
  35 #  ifdef USB_ETH_RNDIS
  36 #    define USB_FRNDIS_INCLUDED
  37 #    include "f_rndis.c"
  38 #    include "rndis.h"
  39 #  endif
  40 #  include "u_ether.h"
  41
  42 static u8 gfs_host_mac[ETH_ALEN];
  43 static struct eth_dev *the_dev;
  44 #  ifdef CONFIG_USB_FUNCTIONFS_ETH
  45 static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
  46                 struct eth_dev *dev);
  47 #  endif
  48 #else
  49 #  define the_dev       NULL
  50 #  define gether_cleanup(dev) do { } while (0)
  51 #  define gfs_host_mac NULL
  52 struct eth_dev;
  53 #endif
  54
  55 #include "f_fs.c"
  56
  57 #define DRIVER_NAME     "g_ffs"
  58 #define DRIVER_DESC     "USB Function Filesystem"
  59 #define DRIVER_VERSION  "24 Aug 2004"
  60
  61 MODULE_DESCRIPTION(DRIVER_DESC);
  62 MODULE_AUTHOR("Michal Nazarewicz");
  63 MODULE_LICENSE("GPL");
  64
  65 #define GFS_VENDOR_ID   0x1d6b  /* Linux Foundation */
  66 #define GFS_PRODUCT_ID  0x0105  /* FunctionFS Gadget */
  67
  68 #define GFS_MAX_DEVS    10
  69
  70 struct gfs_ffs_obj {
  71         const char *name;
  72         bool mounted;
  73         bool desc_ready;
  74         struct ffs_data *ffs_data;
  75 };
  76
  77 USB_GADGET_COMPOSITE_OPTIONS();
  78
  79 USB_ETHERNET_MODULE_PARAMETERS();
  80
  81 static struct usb_device_descriptor gfs_dev_desc = {
  82         .bLength                = sizeof gfs_dev_desc,
  83         .bDescriptorType        = USB_DT_DEVICE,
  84
  85         .bcdUSB                 = cpu_to_le16(0x0200),
  86         .bDeviceClass           = USB_CLASS_PER_INTERFACE,
  87
  88         .idVendor               = cpu_to_le16(GFS_VENDOR_ID),
  89         .idProduct              = cpu_to_le16(GFS_PRODUCT_ID),
  90 };
  91
  92 static char *func_names[GFS_MAX_DEVS];
  93 static unsigned int func_num;
  94
  95 module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
  96 MODULE_PARM_DESC(bDeviceClass, "USB Device class");
  97 module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
  98 MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
  99 module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
 100 MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
 101 module_param_array_named(functions, func_names, charp, &func_num, 0);
 102 MODULE_PARM_DESC(functions, "USB Functions list");
 103
 104 static const struct usb_descriptor_header *gfs_otg_desc[] = {
 105         (const struct usb_descriptor_header *)
 106         &(const struct usb_otg_descriptor) {
 107                 .bLength                = sizeof(struct usb_otg_descriptor),
 108                 .bDescriptorType        = USB_DT_OTG,
 109
 110                 /*
 111                  * REVISIT SRP-only hardware is possible, although
 112                  * it would not be called "OTG" ...
 113                  */
 114                 .bmAttributes           = USB_OTG_SRP | USB_OTG_HNP,
 115         },
 116
 117         NULL
 118 };
 119
 120 /* String IDs are assigned dynamically */
 121 static struct usb_string gfs_strings[] = {
 122         [USB_GADGET_MANUFACTURER_IDX].s = "",
 123         [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
 124         [USB_GADGET_SERIAL_IDX].s = "",
 125 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 126         { .s = "FunctionFS + RNDIS" },
 127 #endif
 128 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 129         { .s = "FunctionFS + ECM" },
 130 #endif
 131 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 132         { .s = "FunctionFS" },
 133 #endif
 134         {  } /* end of list */
 135 };
 136
 137 static struct usb_gadget_strings *gfs_dev_strings[] = {
 138         &(struct usb_gadget_strings) {
 139                 .language       = 0x0409,       /* en-us */
 140                 .strings        = gfs_strings,
 141         },
 142         NULL,
 143 };
 144
 145 struct gfs_configuration {
 146         struct usb_configuration c;
 147         int (*eth)(struct usb_configuration *c, u8 *ethaddr,
 148                         struct eth_dev *dev);
 149 } gfs_configurations[] = {
 150 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 151         {
 152                 .eth            = rndis_bind_config,
 153         },
 154 #endif
 155
 156 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 157         {
 158                 .eth            = eth_bind_config,
 159         },
 160 #endif
 161
 162 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 163         {
 164         },
 165 #endif
 166 };
 167
 168 static int gfs_bind(struct usb_composite_dev *cdev);
 169 static int gfs_unbind(struct usb_composite_dev *cdev);
 170 static int gfs_do_config(struct usb_configuration *c);
 171
 172 static __refdata struct usb_composite_driver gfs_driver = {
 173         .name           = DRIVER_NAME,
 174         .dev            = &gfs_dev_desc,
 175         .strings        = gfs_dev_strings,
 176         .max_speed      = USB_SPEED_HIGH,
 177         .bind           = gfs_bind,
 178         .unbind         = gfs_unbind,
 179 };
 180
 181 static DEFINE_MUTEX(gfs_lock);
 182 static unsigned int missing_funcs;
 183 static bool gfs_ether_setup;
 184 static bool gfs_registered;
 185 static bool gfs_single_func;
 186 static struct gfs_ffs_obj *ffs_tab;
 187
 188 static int __init gfs_init(void)
 189 {
 190         int i;
 191
 192         ENTER();
 193
 194         if (!func_num) {
 195                 gfs_single_func = true;
 196                 func_num = 1;
 197         }
 198
 199         ffs_tab = kcalloc(func_num, sizeof *ffs_tab, GFP_KERNEL);
 200         if (!ffs_tab)
 201                 return -ENOMEM;
 202
 203         if (!gfs_single_func)
 204                 for (i = 0; i < func_num; i++)
 205                         ffs_tab[i].name = func_names[i];
 206
 207         missing_funcs = func_num;
 208
 209         return functionfs_init();
 210 }
 211 module_init(gfs_init);
 212
 213 static void __exit gfs_exit(void)
 214 {
 215         ENTER();
 216         mutex_lock(&gfs_lock);
 217
 218         if (gfs_registered)
 219                 usb_composite_unregister(&gfs_driver);
 220         gfs_registered = false;
 221
 222         functionfs_cleanup();
 223
 224         mutex_unlock(&gfs_lock);
 225         kfree(ffs_tab);
 226 }
 227 module_exit(gfs_exit);
 228
 229 static struct gfs_ffs_obj *gfs_find_dev(const char *dev_name)
 230 {
 231         int i;
 232
 233         ENTER();
 234
 235         if (gfs_single_func)
 236                 return &ffs_tab[0];
 237
 238         for (i = 0; i < func_num; i++)
 239                 if (strcmp(ffs_tab[i].name, dev_name) == 0)
 240                         return &ffs_tab[i];
 241
 242         return NULL;
 243 }
 244
 245 static int functionfs_ready_callback(struct ffs_data *ffs)
 246 {
 247         struct gfs_ffs_obj *ffs_obj;
 248         int ret;
 249
 250         ENTER();
 251         mutex_lock(&gfs_lock);
 252
 253         ffs_obj = ffs->private_data;
 254         if (!ffs_obj) {
 255                 ret = -EINVAL;
 256                 goto done;
 257         }
 258
 259         if (WARN_ON(ffs_obj->desc_ready)) {
 260                 ret = -EBUSY;
 261                 goto done;
 262         }
 263         ffs_obj->desc_ready = true;
 264         ffs_obj->ffs_data = ffs;
 265
 266         if (--missing_funcs) {
 267                 ret = 0;
 268                 goto done;
 269         }
 270
 271         if (gfs_registered) {
 272                 ret = -EBUSY;
 273                 goto done;
 274         }
 275         gfs_registered = true;
 276
 277         ret = usb_composite_probe(&gfs_driver);
 278         if (unlikely(ret < 0))
 279                 gfs_registered = false;
 280
 281 done:
 282         mutex_unlock(&gfs_lock);
 283         return ret;
 284 }
 285
 286 static void functionfs_closed_callback(struct ffs_data *ffs)
 287 {
 288         struct gfs_ffs_obj *ffs_obj;
 289
 290         ENTER();
 291         mutex_lock(&gfs_lock);
 292
 293         ffs_obj = ffs->private_data;
 294         if (!ffs_obj)
 295                 goto done;
 296
 297         ffs_obj->desc_ready = false;
 298         missing_funcs++;
 299
 300         if (gfs_registered)
 301                 usb_composite_unregister(&gfs_driver);
 302         gfs_registered = false;
 303
 304 done:
 305         mutex_unlock(&gfs_lock);
 306 }
 307
 308 static void *functionfs_acquire_dev_callback(const char *dev_name)
 309 {
 310         struct gfs_ffs_obj *ffs_dev;
 311
 312         ENTER();
 313         mutex_lock(&gfs_lock);
 314
 315         ffs_dev = gfs_find_dev(dev_name);
 316         if (!ffs_dev) {
 317                 ffs_dev = ERR_PTR(-ENODEV);
 318                 goto done;
 319         }
 320
 321         if (ffs_dev->mounted) {
 322                 ffs_dev = ERR_PTR(-EBUSY);
 323                 goto done;
 324         }
 325         ffs_dev->mounted = true;
 326
 327 done:
 328         mutex_unlock(&gfs_lock);
 329         return ffs_dev;
 330 }
 331
 332 static void functionfs_release_dev_callback(struct ffs_data *ffs_data)
 333 {
 334         struct gfs_ffs_obj *ffs_dev;
 335
 336         ENTER();
 337         mutex_lock(&gfs_lock);
 338
 339         ffs_dev = ffs_data->private_data;
 340         if (ffs_dev)
 341                 ffs_dev->mounted = false;
 342
 343         mutex_unlock(&gfs_lock);
 344 }
 345
 346 /*
 347  * It is assumed that gfs_bind is called from a context where gfs_lock is held
 348  */
 349 static int gfs_bind(struct usb_composite_dev *cdev)
 350 {
 351         int ret, i;
 352
 353         ENTER();
 354
 355         if (missing_funcs)
 356                 return -ENODEV;
 357 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 358         the_dev = gether_setup(cdev->gadget, dev_addr, host_addr, gfs_host_mac,
 359                                qmult);
 360 #endif
 361         if (IS_ERR(the_dev)) {
 362                 ret = PTR_ERR(the_dev);
 363                 goto error_quick;
 364         }
 365         gfs_ether_setup = true;
 366
 367         ret = usb_string_ids_tab(cdev, gfs_strings);
 368         if (unlikely(ret < 0))
 369                 goto error;
 370         gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 371
 372         for (i = func_num; i--; ) {
 373                 ret = functionfs_bind(ffs_tab[i].ffs_data, cdev);
 374                 if (unlikely(ret < 0)) {
 375                         while (++i < func_num)
 376                                 functionfs_unbind(ffs_tab[i].ffs_data);
 377                         goto error;
 378                 }
 379         }
 380
 381         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 382                 struct gfs_configuration *c = gfs_configurations + i;
 383                 int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
 384
 385                 c->c.label                      = gfs_strings[sid].s;
 386                 c->c.iConfiguration             = gfs_strings[sid].id;
 387                 c->c.bConfigurationValue        = 1 + i;
 388                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 389
 390                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 391                 if (unlikely(ret < 0))
 392                         goto error_unbind;
 393         }
 394         usb_composite_overwrite_options(cdev, &coverwrite);
 395         return 0;
 396
 397 error_unbind:
 398         for (i = 0; i < func_num; i++)
 399                 functionfs_unbind(ffs_tab[i].ffs_data);
 400 error:
 401         gether_cleanup(the_dev);
 402 error_quick:
 403         gfs_ether_setup = false;
 404         return ret;
 405 }
 406
 407 /*
 408  * It is assumed that gfs_unbind is called from a context where gfs_lock is held
 409  */
 410 static int gfs_unbind(struct usb_composite_dev *cdev)
 411 {
 412         int i;
 413
 414         ENTER();
 415
 416         /*
 417          * We may have been called in an error recovery from
 418          * composite_bind() after gfs_unbind() failure so we need to
 419          * check if gfs_ffs_data is not NULL since gfs_bind() handles
 420          * all error recovery itself.  I'd rather we werent called
 421          * from composite on orror recovery, but what you're gonna
 422          * do...?
 423          */
 424         if (gfs_ether_setup)
 425                 gether_cleanup(the_dev);
 426         gfs_ether_setup = false;
 427
 428         for (i = func_num; i--; )
 429                 if (ffs_tab[i].ffs_data)
 430                         functionfs_unbind(ffs_tab[i].ffs_data);
 431
 432         return 0;
 433 }
 434
 435 /*
 436  * It is assumed that gfs_do_config is called from a context where
 437  * gfs_lock is held
 438  */
 439 static int gfs_do_config(struct usb_configuration *c)
 440 {
 441         struct gfs_configuration *gc =
 442                 container_of(c, struct gfs_configuration, c);
 443         int i;
 444         int ret;
 445
 446         if (missing_funcs)
 447                 return -ENODEV;
 448
 449         if (gadget_is_otg(c->cdev->gadget)) {
 450                 c->descriptors = gfs_otg_desc;
 451                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 452         }
 453
 454         if (gc->eth) {
 455                 ret = gc->eth(c, gfs_host_mac, the_dev);
 456                 if (unlikely(ret < 0))
 457                         return ret;
 458         }
 459
 460         for (i = 0; i < func_num; i++) {
 461                 ret = functionfs_bind_config(c->cdev, c, ffs_tab[i].ffs_data);
 462                 if (unlikely(ret < 0))
 463                         return ret;
 464         }
 465
 466         /*
 467          * After previous do_configs there may be some invalid
 468          * pointers in c->interface array.  This happens every time
 469          * a user space function with fewer interfaces than a user
 470          * space function that was run before the new one is run.  The
 471          * compasit's set_config() assumes that if there is no more
 472          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 473          * then there is a NULL pointer after the last interface in
 474          * c->interface array.  We need to make sure this is true.
 475          */
 476         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 477                 c->interface[c->next_interface_id] = NULL;
 478
 479         return 0;
 480 }
 481
 482 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 483
 484 static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
 485                 struct eth_dev *dev)
 486 {
 487         return can_support_ecm(c->cdev->gadget)
 488                 ? ecm_bind_config(c, ethaddr, dev)
 489                 : geth_bind_config(c, ethaddr, dev);
 490 }
 491
 492 #endif