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