drivers/usb/gadget/function/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 #include <linux/module.h>
  21
  22 #include "u_serial.h"
  23 #include "gadget_chips.h"
  24
  25
  26 /*
  27  * This CDC OBEX function support just packages a TTY-ish byte stream.
  28  * A user mode server will put it into "raw" mode and handle all the
  29  * relevant protocol details ... this is just a kernel passthrough.
  30  * When possible, we prevent gadget enumeration until that server is
  31  * ready to handle the commands.
  32  */
  33
  34 struct f_obex {
  35         struct gserial                  port;
  36         u8                              ctrl_id;
  37         u8                              data_id;
  38         u8                              port_num;
  39         u8                              can_activate;
  40 };
  41
  42 static inline struct f_obex *func_to_obex(struct usb_function *f)
  43 {
  44         return container_of(f, struct f_obex, port.func);
  45 }
  46
  47 static inline struct f_obex *port_to_obex(struct gserial *p)
  48 {
  49         return container_of(p, struct f_obex, port);
  50 }
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 #define OBEX_CTRL_IDX   0
  55 #define OBEX_DATA_IDX   1
  56
  57 static struct usb_string obex_string_defs[] = {
  58         [OBEX_CTRL_IDX].s       = "CDC Object Exchange (OBEX)",
  59         [OBEX_DATA_IDX].s       = "CDC OBEX Data",
  60         {  },   /* end of list */
  61 };
  62
  63 static struct usb_gadget_strings obex_string_table = {
  64         .language               = 0x0409,       /* en-US */
  65         .strings                = obex_string_defs,
  66 };
  67
  68 static struct usb_gadget_strings *obex_strings[] = {
  69         &obex_string_table,
  70         NULL,
  71 };
  72
  73 /*-------------------------------------------------------------------------*/
  74
  75 static struct usb_interface_descriptor obex_control_intf = {
  76         .bLength                = sizeof(obex_control_intf),
  77         .bDescriptorType        = USB_DT_INTERFACE,
  78         .bInterfaceNumber       = 0,
  79
  80         .bAlternateSetting      = 0,
  81         .bNumEndpoints          = 0,
  82         .bInterfaceClass        = USB_CLASS_COMM,
  83         .bInterfaceSubClass     = USB_CDC_SUBCLASS_OBEX,
  84 };
  85
  86 static struct usb_interface_descriptor obex_data_nop_intf = {
  87         .bLength                = sizeof(obex_data_nop_intf),
  88         .bDescriptorType        = USB_DT_INTERFACE,
  89         .bInterfaceNumber       = 1,
  90
  91         .bAlternateSetting      = 0,
  92         .bNumEndpoints          = 0,
  93         .bInterfaceClass        = USB_CLASS_CDC_DATA,
  94 };
  95
  96 static struct usb_interface_descriptor obex_data_intf = {
  97         .bLength                = sizeof(obex_data_intf),
  98         .bDescriptorType        = USB_DT_INTERFACE,
  99         .bInterfaceNumber       = 2,
 100
 101         .bAlternateSetting      = 1,
 102         .bNumEndpoints          = 2,
 103         .bInterfaceClass        = USB_CLASS_CDC_DATA,
 104 };
 105
 106 static struct usb_cdc_header_desc obex_cdc_header_desc = {
 107         .bLength                = sizeof(obex_cdc_header_desc),
 108         .bDescriptorType        = USB_DT_CS_INTERFACE,
 109         .bDescriptorSubType     = USB_CDC_HEADER_TYPE,
 110         .bcdCDC                 = cpu_to_le16(0x0120),
 111 };
 112
 113 static struct usb_cdc_union_desc obex_cdc_union_desc = {
 114         .bLength                = sizeof(obex_cdc_union_desc),
 115         .bDescriptorType        = USB_DT_CS_INTERFACE,
 116         .bDescriptorSubType     = USB_CDC_UNION_TYPE,
 117         .bMasterInterface0      = 1,
 118         .bSlaveInterface0       = 2,
 119 };
 120
 121 static struct usb_cdc_obex_desc obex_desc = {
 122         .bLength                = sizeof(obex_desc),
 123         .bDescriptorType        = USB_DT_CS_INTERFACE,
 124         .bDescriptorSubType     = USB_CDC_OBEX_TYPE,
 125         .bcdVersion             = cpu_to_le16(0x0100),
 126 };
 127
 128 /* High-Speed Support */
 129
 130 static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
 131         .bLength                = USB_DT_ENDPOINT_SIZE,
 132         .bDescriptorType        = USB_DT_ENDPOINT,
 133
 134         .bEndpointAddress       = USB_DIR_OUT,
 135         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 136         .wMaxPacketSize         = cpu_to_le16(512),
 137 };
 138
 139 static struct usb_endpoint_descriptor obex_hs_ep_in_desc = {
 140         .bLength                = USB_DT_ENDPOINT_SIZE,
 141         .bDescriptorType        = USB_DT_ENDPOINT,
 142
 143         .bEndpointAddress       = USB_DIR_IN,
 144         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 145         .wMaxPacketSize         = cpu_to_le16(512),
 146 };
 147
 148 static struct usb_descriptor_header *hs_function[] = {
 149         (struct usb_descriptor_header *) &obex_control_intf,
 150         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 151         (struct usb_descriptor_header *) &obex_desc,
 152         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 153
 154         (struct usb_descriptor_header *) &obex_data_nop_intf,
 155         (struct usb_descriptor_header *) &obex_data_intf,
 156         (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
 157         (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
 158         NULL,
 159 };
 160
 161 /* Full-Speed Support */
 162
 163 static struct usb_endpoint_descriptor obex_fs_ep_in_desc = {
 164         .bLength                = USB_DT_ENDPOINT_SIZE,
 165         .bDescriptorType        = USB_DT_ENDPOINT,
 166
 167         .bEndpointAddress       = USB_DIR_IN,
 168         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 169 };
 170
 171 static struct usb_endpoint_descriptor obex_fs_ep_out_desc = {
 172         .bLength                = USB_DT_ENDPOINT_SIZE,
 173         .bDescriptorType        = USB_DT_ENDPOINT,
 174
 175         .bEndpointAddress       = USB_DIR_OUT,
 176         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 177 };
 178
 179 static struct usb_descriptor_header *fs_function[] = {
 180         (struct usb_descriptor_header *) &obex_control_intf,
 181         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 182         (struct usb_descriptor_header *) &obex_desc,
 183         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 184
 185         (struct usb_descriptor_header *) &obex_data_nop_intf,
 186         (struct usb_descriptor_header *) &obex_data_intf,
 187         (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
 188         (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
 189         NULL,
 190 };
 191
 192 /*-------------------------------------------------------------------------*/
 193
 194 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 195 {
 196         struct f_obex           *obex = func_to_obex(f);
 197         struct usb_composite_dev *cdev = f->config->cdev;
 198
 199         if (intf == obex->ctrl_id) {
 200                 if (alt != 0)
 201                         goto fail;
 202                 /* NOP */
 203                 dev_dbg(&cdev->gadget->dev,
 204                         "reset obex ttyGS%d control\n", obex->port_num);
 205
 206         } else if (intf == obex->data_id) {
 207                 if (alt > 1)
 208                         goto fail;
 209
 210                 if (obex->port.in->driver_data) {
 211                         dev_dbg(&cdev->gadget->dev,
 212                                 "reset obex ttyGS%d\n", obex->port_num);
 213                         gserial_disconnect(&obex->port);
 214                 }
 215
 216                 if (!obex->port.in->desc || !obex->port.out->desc) {
 217                         dev_dbg(&cdev->gadget->dev,
 218                                 "init obex ttyGS%d\n", obex->port_num);
 219                         if (config_ep_by_speed(cdev->gadget, f,
 220                                                obex->port.in) ||
 221                             config_ep_by_speed(cdev->gadget, f,
 222                                                obex->port.out)) {
 223                                 obex->port.out->desc = NULL;
 224                                 obex->port.in->desc = NULL;
 225                                 goto fail;
 226                         }
 227                 }
 228
 229                 if (alt == 1) {
 230                         dev_dbg(&cdev->gadget->dev,
 231                                 "activate obex ttyGS%d\n", obex->port_num);
 232                         gserial_connect(&obex->port, obex->port_num);
 233                 }
 234
 235         } else
 236                 goto fail;
 237
 238         return 0;
 239
 240 fail:
 241         return -EINVAL;
 242 }
 243
 244 static int obex_get_alt(struct usb_function *f, unsigned intf)
 245 {
 246         struct f_obex           *obex = func_to_obex(f);
 247
 248         if (intf == obex->ctrl_id)
 249                 return 0;
 250
 251         return obex->port.in->driver_data ? 1 : 0;
 252 }
 253
 254 static void obex_disable(struct usb_function *f)
 255 {
 256         struct f_obex   *obex = func_to_obex(f);
 257         struct usb_composite_dev *cdev = f->config->cdev;
 258
 259         dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
 260         gserial_disconnect(&obex->port);
 261 }
 262
 263 /*-------------------------------------------------------------------------*/
 264
 265 static void obex_connect(struct gserial *g)
 266 {
 267         struct f_obex           *obex = port_to_obex(g);
 268         struct usb_composite_dev *cdev = g->func.config->cdev;
 269         int                     status;
 270
 271         if (!obex->can_activate)
 272                 return;
 273
 274         status = usb_function_activate(&g->func);
 275         if (status)
 276                 dev_dbg(&cdev->gadget->dev,
 277                         "obex ttyGS%d function activate --> %d\n",
 278                         obex->port_num, status);
 279 }
 280
 281 static void obex_disconnect(struct gserial *g)
 282 {
 283         struct f_obex           *obex = port_to_obex(g);
 284         struct usb_composite_dev *cdev = g->func.config->cdev;
 285         int                     status;
 286
 287         if (!obex->can_activate)
 288                 return;
 289
 290         status = usb_function_deactivate(&g->func);
 291         if (status)
 292                 dev_dbg(&cdev->gadget->dev,
 293                         "obex ttyGS%d function deactivate --> %d\n",
 294                         obex->port_num, status);
 295 }
 296
 297 /*-------------------------------------------------------------------------*/
 298
 299 /* Some controllers can't support CDC OBEX ... */
 300 static inline bool can_support_obex(struct usb_configuration *c)
 301 {
 302         /* Since the first interface is a NOP, we can ignore the
 303          * issue of multi-interface support on most controllers.
 304          *
 305          * Altsettings are mandatory, however...
 306          */
 307         if (!gadget_supports_altsettings(c->cdev->gadget))
 308                 return false;
 309
 310         /* everything else is *probably* fine ... */
 311         return true;
 312 }
 313
 314 static int obex_bind(struct usb_configuration *c, struct usb_function *f)
 315 {
 316         struct usb_composite_dev *cdev = c->cdev;
 317         struct f_obex           *obex = func_to_obex(f);
 318         struct usb_string       *us;
 319         int                     status;
 320         struct usb_ep           *ep;
 321
 322         if (!can_support_obex(c))
 323                 return -EINVAL;
 324
 325         us = usb_gstrings_attach(cdev, obex_strings,
 326                                  ARRAY_SIZE(obex_string_defs));
 327         if (IS_ERR(us))
 328                 return PTR_ERR(us);
 329         obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
 330         obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
 331         obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
 332
 333         /* allocate instance-specific interface IDs, and patch descriptors */
 334
 335         status = usb_interface_id(c, f);
 336         if (status < 0)
 337                 goto fail;
 338         obex->ctrl_id = status;
 339
 340         obex_control_intf.bInterfaceNumber = status;
 341         obex_cdc_union_desc.bMasterInterface0 = status;
 342
 343         status = usb_interface_id(c, f);
 344         if (status < 0)
 345                 goto fail;
 346         obex->data_id = status;
 347
 348         obex_data_nop_intf.bInterfaceNumber = status;
 349         obex_data_intf.bInterfaceNumber = status;
 350         obex_cdc_union_desc.bSlaveInterface0 = status;
 351
 352         /* allocate instance-specific endpoints */
 353
 354         status = -ENODEV;
 355         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 356         if (!ep)
 357                 goto fail;
 358         obex->port.in = ep;
 359         ep->driver_data = cdev; /* claim */
 360
 361         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 362         if (!ep)
 363                 goto fail;
 364         obex->port.out = ep;
 365         ep->driver_data = cdev; /* claim */
 366
 367         /* support all relevant hardware speeds... we expect that when
 368          * hardware is dual speed, all bulk-capable endpoints work at
 369          * both speeds
 370          */
 371
 372         obex_hs_ep_in_desc.bEndpointAddress =
 373                 obex_fs_ep_in_desc.bEndpointAddress;
 374         obex_hs_ep_out_desc.bEndpointAddress =
 375                 obex_fs_ep_out_desc.bEndpointAddress;
 376
 377         status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
 378         if (status)
 379                 goto fail;
 380
 381         /* Avoid letting this gadget enumerate until the userspace
 382          * OBEX server is active.
 383          */
 384         status = usb_function_deactivate(f);
 385         if (status < 0)
 386                 WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
 387                         obex->port_num, status);
 388         else
 389                 obex->can_activate = true;
 390
 391
 392         dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 393                 obex->port_num,
 394                 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 395                 obex->port.in->name, obex->port.out->name);
 396
 397         return 0;
 398
 399 fail:
 400         usb_free_all_descriptors(f);
 401         /* we might as well release our claims on endpoints */
 402         if (obex->port.out)
 403                 obex->port.out->driver_data = NULL;
 404         if (obex->port.in)
 405                 obex->port.in->driver_data = NULL;
 406
 407         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 408
 409         return status;
 410 }
 411
 412 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 413 {
 414         return container_of(to_config_group(item), struct f_serial_opts,
 415                             func_inst.group);
 416 }
 417
 418 CONFIGFS_ATTR_STRUCT(f_serial_opts);
 419 static ssize_t f_obex_attr_show(struct config_item *item,
 420                                 struct configfs_attribute *attr,
 421                                 char *page)
 422 {
 423         struct f_serial_opts *opts = to_f_serial_opts(item);
 424         struct f_serial_opts_attribute *f_serial_opts_attr =
 425                 container_of(attr, struct f_serial_opts_attribute, attr);
 426         ssize_t ret = 0;
 427
 428         if (f_serial_opts_attr->show)
 429                 ret = f_serial_opts_attr->show(opts, page);
 430
 431         return ret;
 432 }
 433
 434 static void obex_attr_release(struct config_item *item)
 435 {
 436         struct f_serial_opts *opts = to_f_serial_opts(item);
 437
 438         usb_put_function_instance(&opts->func_inst);
 439 }
 440
 441 static struct configfs_item_operations obex_item_ops = {
 442         .release        = obex_attr_release,
 443         .show_attribute = f_obex_attr_show,
 444 };
 445
 446 static ssize_t f_obex_port_num_show(struct f_serial_opts *opts, char *page)
 447 {
 448         return sprintf(page, "%u\n", opts->port_num);
 449 }
 450
 451 static struct f_serial_opts_attribute f_obex_port_num =
 452         __CONFIGFS_ATTR_RO(port_num, f_obex_port_num_show);
 453
 454 static struct configfs_attribute *acm_attrs[] = {
 455         &f_obex_port_num.attr,
 456         NULL,
 457 };
 458
 459 static struct config_item_type obex_func_type = {
 460         .ct_item_ops    = &obex_item_ops,
 461         .ct_attrs       = acm_attrs,
 462         .ct_owner       = THIS_MODULE,
 463 };
 464
 465 static void obex_free_inst(struct usb_function_instance *f)
 466 {
 467         struct f_serial_opts *opts;
 468
 469         opts = container_of(f, struct f_serial_opts, func_inst);
 470         gserial_free_line(opts->port_num);
 471         kfree(opts);
 472 }
 473
 474 static struct usb_function_instance *obex_alloc_inst(void)
 475 {
 476         struct f_serial_opts *opts;
 477         int ret;
 478
 479         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 480         if (!opts)
 481                 return ERR_PTR(-ENOMEM);
 482
 483         opts->func_inst.free_func_inst = obex_free_inst;
 484         ret = gserial_alloc_line(&opts->port_num);
 485         if (ret) {
 486                 kfree(opts);
 487                 return ERR_PTR(ret);
 488         }
 489         config_group_init_type_name(&opts->func_inst.group, "",
 490                                     &obex_func_type);
 491
 492         return &opts->func_inst;
 493 }
 494
 495 static void obex_free(struct usb_function *f)
 496 {
 497         struct f_obex *obex;
 498
 499         obex = func_to_obex(f);
 500         kfree(obex);
 501 }
 502
 503 static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 504 {
 505         usb_free_all_descriptors(f);
 506 }
 507
 508 static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 509 {
 510         struct f_obex   *obex;
 511         struct f_serial_opts *opts;
 512
 513         /* allocate and initialize one new instance */
 514         obex = kzalloc(sizeof(*obex), GFP_KERNEL);
 515         if (!obex)
 516                 return ERR_PTR(-ENOMEM);
 517
 518         opts = container_of(fi, struct f_serial_opts, func_inst);
 519
 520         obex->port_num = opts->port_num;
 521
 522         obex->port.connect = obex_connect;
 523         obex->port.disconnect = obex_disconnect;
 524
 525         obex->port.func.name = "obex";
 526         /* descriptors are per-instance copies */
 527         obex->port.func.bind = obex_bind;
 528         obex->port.func.unbind = obex_unbind;
 529         obex->port.func.set_alt = obex_set_alt;
 530         obex->port.func.get_alt = obex_get_alt;
 531         obex->port.func.disable = obex_disable;
 532         obex->port.func.free_func = obex_free;
 533
 534         return &obex->port.func;
 535 }
 536
 537 DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 538 MODULE_AUTHOR("Felipe Balbi");
 539 MODULE_LICENSE("GPL");