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