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