drivers/usb/gadget/f_obex.c

   1 /*
   2  * f_obex.c -- USB CDC OBEX function driver
   3  *
   4  * Copyright (C) 2008 Nokia Corporation
   5  * Contact: Felipe Balbi <felipe.balbi@nokia.com>
   6  *
   7  * Based on f_acm.c by Al Borchers and David Brownell.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 /* #define VERBOSE_DEBUG */
  25
  26 #include <linux/slab.h>
  27 #include <linux/kernel.h>
  28 #include <linux/device.h>
  29
  30 #include "u_serial.h"
  31 #include "gadget_chips.h"
  32
  33
  34 /*
  35  * This CDC OBEX function support just packages a TTY-ish byte stream.
  36  * A user mode server will put it into "raw" mode and handle all the
  37  * relevant protocol details ... this is just a kernel passthrough.
  38  * When possible, we prevent gadget enumeration until that server is
  39  * ready to handle the commands.
  40  */
  41
  42 struct obex_ep_descs {
  43         struct usb_endpoint_descriptor  *obex_in;
  44         struct usb_endpoint_descriptor  *obex_out;
  45 };
  46
  47 struct f_obex {
  48         struct gserial                  port;
  49         u8                              ctrl_id;
  50         u8                              data_id;
  51         u8                              port_num;
  52         u8                              can_activate;
  53
  54         struct obex_ep_descs            fs;
  55         struct obex_ep_descs            hs;
  56 };
  57
  58 static inline struct f_obex *func_to_obex(struct usb_function *f)
  59 {
  60         return container_of(f, struct f_obex, port.func);
  61 }
  62
  63 static inline struct f_obex *port_to_obex(struct gserial *p)
  64 {
  65         return container_of(p, struct f_obex, port);
  66 }
  67
  68 /*-------------------------------------------------------------------------*/
  69
  70 #define OBEX_CTRL_IDX   0
  71 #define OBEX_DATA_IDX   1
  72
  73 static struct usb_string obex_string_defs[] = {
  74         [OBEX_CTRL_IDX].s       = "CDC Object Exchange (OBEX)",
  75         [OBEX_DATA_IDX].s       = "CDC OBEX Data",
  76         {  },   /* end of list */
  77 };
  78
  79 static struct usb_gadget_strings obex_string_table = {
  80         .language               = 0x0409,       /* en-US */
  81         .strings                = obex_string_defs,
  82 };
  83
  84 static struct usb_gadget_strings *obex_strings[] = {
  85         &obex_string_table,
  86         NULL,
  87 };
  88
  89 /*-------------------------------------------------------------------------*/
  90
  91 static struct usb_interface_descriptor obex_control_intf __initdata = {
  92         .bLength                = sizeof(obex_control_intf),
  93         .bDescriptorType        = USB_DT_INTERFACE,
  94         .bInterfaceNumber       = 0,
  95
  96         .bAlternateSetting      = 0,
  97         .bNumEndpoints          = 0,
  98         .bInterfaceClass        = USB_CLASS_COMM,
  99         .bInterfaceSubClass     = USB_CDC_SUBCLASS_OBEX,
 100 };
 101
 102 static struct usb_interface_descriptor obex_data_nop_intf __initdata = {
 103         .bLength                = sizeof(obex_data_nop_intf),
 104         .bDescriptorType        = USB_DT_INTERFACE,
 105         .bInterfaceNumber       = 1,
 106
 107         .bAlternateSetting      = 0,
 108         .bNumEndpoints          = 0,
 109         .bInterfaceClass        = USB_CLASS_CDC_DATA,
 110 };
 111
 112 static struct usb_interface_descriptor obex_data_intf __initdata = {
 113         .bLength                = sizeof(obex_data_intf),
 114         .bDescriptorType        = USB_DT_INTERFACE,
 115         .bInterfaceNumber       = 2,
 116
 117         .bAlternateSetting      = 1,
 118         .bNumEndpoints          = 2,
 119         .bInterfaceClass        = USB_CLASS_CDC_DATA,
 120 };
 121
 122 static struct usb_cdc_header_desc obex_cdc_header_desc __initdata = {
 123         .bLength                = sizeof(obex_cdc_header_desc),
 124         .bDescriptorType        = USB_DT_CS_INTERFACE,
 125         .bDescriptorSubType     = USB_CDC_HEADER_TYPE,
 126         .bcdCDC                 = cpu_to_le16(0x0120),
 127 };
 128
 129 static struct usb_cdc_union_desc obex_cdc_union_desc __initdata = {
 130         .bLength                = sizeof(obex_cdc_union_desc),
 131         .bDescriptorType        = USB_DT_CS_INTERFACE,
 132         .bDescriptorSubType     = USB_CDC_UNION_TYPE,
 133         .bMasterInterface0      = 1,
 134         .bSlaveInterface0       = 2,
 135 };
 136
 137 static struct usb_cdc_obex_desc obex_desc __initdata = {
 138         .bLength                = sizeof(obex_desc),
 139         .bDescriptorType        = USB_DT_CS_INTERFACE,
 140         .bDescriptorSubType     = USB_CDC_OBEX_TYPE,
 141         .bcdVersion             = cpu_to_le16(0x0100),
 142 };
 143
 144 /* High-Speed Support */
 145
 146 static struct usb_endpoint_descriptor obex_hs_ep_out_desc __initdata = {
 147         .bLength                = USB_DT_ENDPOINT_SIZE,
 148         .bDescriptorType        = USB_DT_ENDPOINT,
 149
 150         .bEndpointAddress       = USB_DIR_OUT,
 151         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 152         .wMaxPacketSize         = cpu_to_le16(512),
 153 };
 154
 155 static struct usb_endpoint_descriptor obex_hs_ep_in_desc __initdata = {
 156         .bLength                = USB_DT_ENDPOINT_SIZE,
 157         .bDescriptorType        = USB_DT_ENDPOINT,
 158
 159         .bEndpointAddress       = USB_DIR_IN,
 160         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 161         .wMaxPacketSize         = cpu_to_le16(512),
 162 };
 163
 164 static struct usb_descriptor_header *hs_function[] __initdata = {
 165         (struct usb_descriptor_header *) &obex_control_intf,
 166         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 167         (struct usb_descriptor_header *) &obex_desc,
 168         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 169
 170         (struct usb_descriptor_header *) &obex_data_nop_intf,
 171         (struct usb_descriptor_header *) &obex_data_intf,
 172         (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
 173         (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
 174         NULL,
 175 };
 176
 177 /* Full-Speed Support */
 178
 179 static struct usb_endpoint_descriptor obex_fs_ep_in_desc __initdata = {
 180         .bLength                = USB_DT_ENDPOINT_SIZE,
 181         .bDescriptorType        = USB_DT_ENDPOINT,
 182
 183         .bEndpointAddress       = USB_DIR_IN,
 184         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 185 };
 186
 187 static struct usb_endpoint_descriptor obex_fs_ep_out_desc __initdata = {
 188         .bLength                = USB_DT_ENDPOINT_SIZE,
 189         .bDescriptorType        = USB_DT_ENDPOINT,
 190
 191         .bEndpointAddress       = USB_DIR_OUT,
 192         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 193 };
 194
 195 static struct usb_descriptor_header *fs_function[] __initdata = {
 196         (struct usb_descriptor_header *) &obex_control_intf,
 197         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 198         (struct usb_descriptor_header *) &obex_desc,
 199         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 200
 201         (struct usb_descriptor_header *) &obex_data_nop_intf,
 202         (struct usb_descriptor_header *) &obex_data_intf,
 203         (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
 204         (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
 205         NULL,
 206 };
 207
 208 /*-------------------------------------------------------------------------*/
 209
 210 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 211 {
 212         struct f_obex           *obex = func_to_obex(f);
 213         struct usb_composite_dev *cdev = f->config->cdev;
 214
 215         if (intf == obex->ctrl_id) {
 216                 if (alt != 0)
 217                         goto fail;
 218                 /* NOP */
 219                 DBG(cdev, "reset obex ttyGS%d control\n", obex->port_num);
 220
 221         } else if (intf == obex->data_id) {
 222                 if (alt > 1)
 223                         goto fail;
 224
 225                 if (obex->port.in->driver_data) {
 226                         DBG(cdev, "reset obex ttyGS%d\n", obex->port_num);
 227                         gserial_disconnect(&obex->port);
 228                 }
 229
 230                 if (!obex->port.in_desc) {
 231                         DBG(cdev, "init obex ttyGS%d\n", obex->port_num);
 232                         obex->port.in_desc = ep_choose(cdev->gadget,
 233                                         obex->hs.obex_in, obex->fs.obex_in);
 234                         obex->port.out_desc = ep_choose(cdev->gadget,
 235                                         obex->hs.obex_out, obex->fs.obex_out);
 236                 }
 237
 238                 if (alt == 1) {
 239                         DBG(cdev, "activate obex ttyGS%d\n", obex->port_num);
 240                         gserial_connect(&obex->port, obex->port_num);
 241                 }
 242
 243         } else
 244                 goto fail;
 245
 246         return 0;
 247
 248 fail:
 249         return -EINVAL;
 250 }
 251
 252 static int obex_get_alt(struct usb_function *f, unsigned intf)
 253 {
 254         struct f_obex           *obex = func_to_obex(f);
 255
 256         if (intf == obex->ctrl_id)
 257                 return 0;
 258
 259         return obex->port.in->driver_data ? 1 : 0;
 260 }
 261
 262 static void obex_disable(struct usb_function *f)
 263 {
 264         struct f_obex   *obex = func_to_obex(f);
 265         struct usb_composite_dev *cdev = f->config->cdev;
 266
 267         DBG(cdev, "obex ttyGS%d disable\n", obex->port_num);
 268         gserial_disconnect(&obex->port);
 269 }
 270
 271 /*-------------------------------------------------------------------------*/
 272
 273 static void obex_connect(struct gserial *g)
 274 {
 275         struct f_obex           *obex = port_to_obex(g);
 276         struct usb_composite_dev *cdev = g->func.config->cdev;
 277         int                     status;
 278
 279         if (!obex->can_activate)
 280                 return;
 281
 282         status = usb_function_activate(&g->func);
 283         if (status)
 284                 DBG(cdev, "obex ttyGS%d function activate --> %d\n",
 285                         obex->port_num, status);
 286 }
 287
 288 static void obex_disconnect(struct gserial *g)
 289 {
 290         struct f_obex           *obex = port_to_obex(g);
 291         struct usb_composite_dev *cdev = g->func.config->cdev;
 292         int                     status;
 293
 294         if (!obex->can_activate)
 295                 return;
 296
 297         status = usb_function_deactivate(&g->func);
 298         if (status)
 299                 DBG(cdev, "obex ttyGS%d function deactivate --> %d\n",
 300                         obex->port_num, status);
 301 }
 302
 303 /*-------------------------------------------------------------------------*/
 304
 305 static int __init
 306 obex_bind(struct usb_configuration *c, struct usb_function *f)
 307 {
 308         struct usb_composite_dev *cdev = c->cdev;
 309         struct f_obex           *obex = func_to_obex(f);
 310         int                     status;
 311         struct usb_ep           *ep;
 312
 313         /* allocate instance-specific interface IDs, and patch descriptors */
 314
 315         status = usb_interface_id(c, f);
 316         if (status < 0)
 317                 goto fail;
 318         obex->ctrl_id = status;
 319
 320         obex_control_intf.bInterfaceNumber = status;
 321         obex_cdc_union_desc.bMasterInterface0 = status;
 322
 323         status = usb_interface_id(c, f);
 324         if (status < 0)
 325                 goto fail;
 326         obex->data_id = status;
 327
 328         obex_data_nop_intf.bInterfaceNumber = status;
 329         obex_data_intf.bInterfaceNumber = status;
 330         obex_cdc_union_desc.bSlaveInterface0 = status;
 331
 332         /* allocate instance-specific endpoints */
 333
 334         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 335         if (!ep)
 336                 goto fail;
 337         obex->port.in = ep;
 338         ep->driver_data = cdev; /* claim */
 339
 340         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 341         if (!ep)
 342                 goto fail;
 343         obex->port.out = ep;
 344         ep->driver_data = cdev; /* claim */
 345
 346         /* copy descriptors, and track endpoint copies */
 347         f->descriptors = usb_copy_descriptors(fs_function);
 348
 349         obex->fs.obex_in = usb_find_endpoint(fs_function,
 350                         f->descriptors, &obex_fs_ep_in_desc);
 351         obex->fs.obex_out = usb_find_endpoint(fs_function,
 352                         f->descriptors, &obex_fs_ep_out_desc);
 353
 354         /* support all relevant hardware speeds... we expect that when
 355          * hardware is dual speed, all bulk-capable endpoints work at
 356          * both speeds
 357          */
 358         if (gadget_is_dualspeed(c->cdev->gadget)) {
 359
 360                 obex_hs_ep_in_desc.bEndpointAddress =
 361                                 obex_fs_ep_in_desc.bEndpointAddress;
 362                 obex_hs_ep_out_desc.bEndpointAddress =
 363                                 obex_fs_ep_out_desc.bEndpointAddress;
 364
 365                 /* copy descriptors, and track endpoint copies */
 366                 f->hs_descriptors = usb_copy_descriptors(hs_function);
 367
 368                 obex->hs.obex_in = usb_find_endpoint(hs_function,
 369                                 f->hs_descriptors, &obex_hs_ep_in_desc);
 370                 obex->hs.obex_out = usb_find_endpoint(hs_function,
 371                                 f->hs_descriptors, &obex_hs_ep_out_desc);
 372         }
 373
 374         /* Avoid letting this gadget enumerate until the userspace
 375          * OBEX server is active.
 376          */
 377         status = usb_function_deactivate(f);
 378         if (status < 0)
 379                 WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
 380                         obex->port_num, status);
 381         else
 382                 obex->can_activate = true;
 383
 384
 385         DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 386                         obex->port_num,
 387                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 388                         obex->port.in->name, obex->port.out->name);
 389
 390         return 0;
 391
 392 fail:
 393         /* we might as well release our claims on endpoints */
 394         if (obex->port.out)
 395                 obex->port.out->driver_data = NULL;
 396         if (obex->port.in)
 397                 obex->port.in->driver_data = NULL;
 398
 399         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 400
 401         return status;
 402 }
 403
 404 static void
 405 obex_unbind(struct usb_configuration *c, struct usb_function *f)
 406 {
 407         if (gadget_is_dualspeed(c->cdev->gadget))
 408                 usb_free_descriptors(f->hs_descriptors);
 409         usb_free_descriptors(f->descriptors);
 410         kfree(func_to_obex(f));
 411 }
 412
 413 /* Some controllers can't support CDC OBEX ... */
 414 static inline bool can_support_obex(struct usb_configuration *c)
 415 {
 416         /* Since the first interface is a NOP, we can ignore the
 417          * issue of multi-interface support on most controllers.
 418          *
 419          * Altsettings are mandatory, however...
 420          */
 421         if (!gadget_supports_altsettings(c->cdev->gadget))
 422                 return false;
 423
 424         /* everything else is *probably* fine ... */
 425         return true;
 426 }
 427
 428 /**
 429  * obex_bind_config - add a CDC OBEX function to a configuration
 430  * @c: the configuration to support the CDC OBEX instance
 431  * @port_num: /dev/ttyGS* port this interface will use
 432  * Context: single threaded during gadget setup
 433  *
 434  * Returns zero on success, else negative errno.
 435  *
 436  * Caller must have called @gserial_setup() with enough ports to
 437  * handle all the ones it binds.  Caller is also responsible
 438  * for calling @gserial_cleanup() before module unload.
 439  */
 440 int __init obex_bind_config(struct usb_configuration *c, u8 port_num)
 441 {
 442         struct f_obex   *obex;
 443         int             status;
 444
 445         if (!can_support_obex(c))
 446                 return -EINVAL;
 447
 448         /* maybe allocate device-global string IDs, and patch descriptors */
 449         if (obex_string_defs[OBEX_CTRL_IDX].id == 0) {
 450                 status = usb_string_id(c->cdev);
 451                 if (status < 0)
 452                         return status;
 453                 obex_string_defs[OBEX_CTRL_IDX].id = status;
 454
 455                 obex_control_intf.iInterface = status;
 456
 457                 status = usb_string_id(c->cdev);
 458                 if (status < 0)
 459                         return status;
 460                 obex_string_defs[OBEX_DATA_IDX].id = status;
 461
 462                 obex_data_nop_intf.iInterface =
 463                         obex_data_intf.iInterface = status;
 464         }
 465
 466         /* allocate and initialize one new instance */
 467         obex = kzalloc(sizeof *obex, GFP_KERNEL);
 468         if (!obex)
 469                 return -ENOMEM;
 470
 471         obex->port_num = port_num;
 472
 473         obex->port.connect = obex_connect;
 474         obex->port.disconnect = obex_disconnect;
 475
 476         obex->port.func.name = "obex";
 477         obex->port.func.strings = obex_strings;
 478         /* descriptors are per-instance copies */
 479         obex->port.func.bind = obex_bind;
 480         obex->port.func.unbind = obex_unbind;
 481         obex->port.func.set_alt = obex_set_alt;
 482         obex->port.func.get_alt = obex_get_alt;
 483         obex->port.func.disable = obex_disable;
 484
 485         status = usb_add_function(c, &obex->port.func);
 486         if (status)
 487                 kfree(obex);
 488
 489         return status;
 490 }
 491
 492 MODULE_AUTHOR("Felipe Balbi");
 493 MODULE_LICENSE("GPL");