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 #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                 DBG(cdev, "reset obex ttyGS%d control\n", obex->port_num);
 204
 205         } else if (intf == obex->data_id) {
 206                 if (alt > 1)
 207                         goto fail;
 208
 209                 if (obex->port.in->driver_data) {
 210                         DBG(cdev, "reset obex ttyGS%d\n", obex->port_num);
 211                         gserial_disconnect(&obex->port);
 212                 }
 213
 214                 if (!obex->port.in->desc || !obex->port.out->desc) {
 215                         DBG(cdev, "init obex ttyGS%d\n", obex->port_num);
 216                         if (config_ep_by_speed(cdev->gadget, f,
 217                                                obex->port.in) ||
 218                             config_ep_by_speed(cdev->gadget, f,
 219                                                obex->port.out)) {
 220                                 obex->port.out->desc = NULL;
 221                                 obex->port.in->desc = NULL;
 222                                 goto fail;
 223                         }
 224                 }
 225
 226                 if (alt == 1) {
 227                         DBG(cdev, "activate obex ttyGS%d\n", obex->port_num);
 228                         gserial_connect(&obex->port, obex->port_num);
 229                 }
 230
 231         } else
 232                 goto fail;
 233
 234         return 0;
 235
 236 fail:
 237         return -EINVAL;
 238 }
 239
 240 static int obex_get_alt(struct usb_function *f, unsigned intf)
 241 {
 242         struct f_obex           *obex = func_to_obex(f);
 243
 244         if (intf == obex->ctrl_id)
 245                 return 0;
 246
 247         return obex->port.in->driver_data ? 1 : 0;
 248 }
 249
 250 static void obex_disable(struct usb_function *f)
 251 {
 252         struct f_obex   *obex = func_to_obex(f);
 253         struct usb_composite_dev *cdev = f->config->cdev;
 254
 255         DBG(cdev, "obex ttyGS%d disable\n", obex->port_num);
 256         gserial_disconnect(&obex->port);
 257 }
 258
 259 /*-------------------------------------------------------------------------*/
 260
 261 static void obex_connect(struct gserial *g)
 262 {
 263         struct f_obex           *obex = port_to_obex(g);
 264         struct usb_composite_dev *cdev = g->func.config->cdev;
 265         int                     status;
 266
 267         if (!obex->can_activate)
 268                 return;
 269
 270         status = usb_function_activate(&g->func);
 271         if (status)
 272                 DBG(cdev, "obex ttyGS%d function activate --> %d\n",
 273                         obex->port_num, status);
 274 }
 275
 276 static void obex_disconnect(struct gserial *g)
 277 {
 278         struct f_obex           *obex = port_to_obex(g);
 279         struct usb_composite_dev *cdev = g->func.config->cdev;
 280         int                     status;
 281
 282         if (!obex->can_activate)
 283                 return;
 284
 285         status = usb_function_deactivate(&g->func);
 286         if (status)
 287                 DBG(cdev, "obex ttyGS%d function deactivate --> %d\n",
 288                         obex->port_num, status);
 289 }
 290
 291 /*-------------------------------------------------------------------------*/
 292
 293 /* Some controllers can't support CDC OBEX ... */
 294 static inline bool can_support_obex(struct usb_configuration *c)
 295 {
 296         /* Since the first interface is a NOP, we can ignore the
 297          * issue of multi-interface support on most controllers.
 298          *
 299          * Altsettings are mandatory, however...
 300          */
 301         if (!gadget_supports_altsettings(c->cdev->gadget))
 302                 return false;
 303
 304         /* everything else is *probably* fine ... */
 305         return true;
 306 }
 307
 308 static int obex_bind(struct usb_configuration *c, struct usb_function *f)
 309 {
 310         struct usb_composite_dev *cdev = c->cdev;
 311         struct f_obex           *obex = func_to_obex(f);
 312         struct usb_string       *us;
 313         int                     status;
 314         struct usb_ep           *ep;
 315
 316         if (!can_support_obex(c))
 317                 return -EINVAL;
 318
 319         us = usb_gstrings_attach(cdev, obex_strings,
 320                                  ARRAY_SIZE(obex_string_defs));
 321         if (IS_ERR(us))
 322                 return PTR_ERR(us);
 323         obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
 324         obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
 325         obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
 326
 327         /* allocate instance-specific interface IDs, and patch descriptors */
 328
 329         status = usb_interface_id(c, f);
 330         if (status < 0)
 331                 goto fail;
 332         obex->ctrl_id = status;
 333
 334         obex_control_intf.bInterfaceNumber = status;
 335         obex_cdc_union_desc.bMasterInterface0 = status;
 336
 337         status = usb_interface_id(c, f);
 338         if (status < 0)
 339                 goto fail;
 340         obex->data_id = status;
 341
 342         obex_data_nop_intf.bInterfaceNumber = status;
 343         obex_data_intf.bInterfaceNumber = status;
 344         obex_cdc_union_desc.bSlaveInterface0 = status;
 345
 346         /* allocate instance-specific endpoints */
 347
 348         status = -ENODEV;
 349         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 350         if (!ep)
 351                 goto fail;
 352         obex->port.in = ep;
 353         ep->driver_data = cdev; /* claim */
 354
 355         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 356         if (!ep)
 357                 goto fail;
 358         obex->port.out = ep;
 359         ep->driver_data = cdev; /* claim */
 360
 361         /* support all relevant hardware speeds... we expect that when
 362          * hardware is dual speed, all bulk-capable endpoints work at
 363          * both speeds
 364          */
 365
 366         obex_hs_ep_in_desc.bEndpointAddress =
 367                 obex_fs_ep_in_desc.bEndpointAddress;
 368         obex_hs_ep_out_desc.bEndpointAddress =
 369                 obex_fs_ep_out_desc.bEndpointAddress;
 370
 371         status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
 372         if (status)
 373                 goto fail;
 374
 375         /* Avoid letting this gadget enumerate until the userspace
 376          * OBEX server is active.
 377          */
 378         status = usb_function_deactivate(f);
 379         if (status < 0)
 380                 WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
 381                         obex->port_num, status);
 382         else
 383                 obex->can_activate = true;
 384
 385
 386         DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 387                         obex->port_num,
 388                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 389                         obex->port.in->name, obex->port.out->name);
 390
 391         return 0;
 392
 393 fail:
 394         usb_free_all_descriptors(f);
 395         /* we might as well release our claims on endpoints */
 396         if (obex->port.out)
 397                 obex->port.out->driver_data = NULL;
 398         if (obex->port.in)
 399                 obex->port.in->driver_data = NULL;
 400
 401         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 402
 403         return status;
 404 }
 405
 406 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 407 {
 408         return container_of(to_config_group(item), struct f_serial_opts,
 409                             func_inst.group);
 410 }
 411
 412 CONFIGFS_ATTR_STRUCT(f_serial_opts);
 413 static ssize_t f_obex_attr_show(struct config_item *item,
 414                                 struct configfs_attribute *attr,
 415                                 char *page)
 416 {
 417         struct f_serial_opts *opts = to_f_serial_opts(item);
 418         struct f_serial_opts_attribute *f_serial_opts_attr =
 419                 container_of(attr, struct f_serial_opts_attribute, attr);
 420         ssize_t ret = 0;
 421
 422         if (f_serial_opts_attr->show)
 423                 ret = f_serial_opts_attr->show(opts, page);
 424
 425         return ret;
 426 }
 427
 428 static void obex_attr_release(struct config_item *item)
 429 {
 430         struct f_serial_opts *opts = to_f_serial_opts(item);
 431
 432         usb_put_function_instance(&opts->func_inst);
 433 }
 434
 435 static struct configfs_item_operations obex_item_ops = {
 436         .release        = obex_attr_release,
 437         .show_attribute = f_obex_attr_show,
 438 };
 439
 440 static ssize_t f_obex_port_num_show(struct f_serial_opts *opts, char *page)
 441 {
 442         return sprintf(page, "%u\n", opts->port_num);
 443 }
 444
 445 static struct f_serial_opts_attribute f_obex_port_num =
 446         __CONFIGFS_ATTR_RO(port_num, f_obex_port_num_show);
 447
 448 static struct configfs_attribute *acm_attrs[] = {
 449         &f_obex_port_num.attr,
 450         NULL,
 451 };
 452
 453 static struct config_item_type obex_func_type = {
 454         .ct_item_ops    = &obex_item_ops,
 455         .ct_attrs       = acm_attrs,
 456         .ct_owner       = THIS_MODULE,
 457 };
 458
 459 static void obex_free_inst(struct usb_function_instance *f)
 460 {
 461         struct f_serial_opts *opts;
 462
 463         opts = container_of(f, struct f_serial_opts, func_inst);
 464         gserial_free_line(opts->port_num);
 465         kfree(opts);
 466 }
 467
 468 static struct usb_function_instance *obex_alloc_inst(void)
 469 {
 470         struct f_serial_opts *opts;
 471         int ret;
 472
 473         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 474         if (!opts)
 475                 return ERR_PTR(-ENOMEM);
 476
 477         opts->func_inst.free_func_inst = obex_free_inst;
 478         ret = gserial_alloc_line(&opts->port_num);
 479         if (ret) {
 480                 kfree(opts);
 481                 return ERR_PTR(ret);
 482         }
 483         config_group_init_type_name(&opts->func_inst.group, "",
 484                                     &obex_func_type);
 485
 486         return &opts->func_inst;
 487 }
 488
 489 static void obex_free(struct usb_function *f)
 490 {
 491         struct f_obex *obex;
 492
 493         obex = func_to_obex(f);
 494         kfree(obex);
 495 }
 496
 497 static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 498 {
 499         usb_free_all_descriptors(f);
 500 }
 501
 502 static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 503 {
 504         struct f_obex   *obex;
 505         struct f_serial_opts *opts;
 506
 507         /* allocate and initialize one new instance */
 508         obex = kzalloc(sizeof(*obex), GFP_KERNEL);
 509         if (!obex)
 510                 return ERR_PTR(-ENOMEM);
 511
 512         opts = container_of(fi, struct f_serial_opts, func_inst);
 513
 514         obex->port_num = opts->port_num;
 515
 516         obex->port.connect = obex_connect;
 517         obex->port.disconnect = obex_disconnect;
 518
 519         obex->port.func.name = "obex";
 520         /* descriptors are per-instance copies */
 521         obex->port.func.bind = obex_bind;
 522         obex->port.func.unbind = obex_unbind;
 523         obex->port.func.set_alt = obex_set_alt;
 524         obex->port.func.get_alt = obex_get_alt;
 525         obex->port.func.disable = obex_disable;
 526         obex->port.func.free_func = obex_free;
 527
 528         return &obex->port.func;
 529 }
 530
 531 DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 532 MODULE_AUTHOR("Felipe Balbi");
 533 MODULE_LICENSE("GPL");