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
  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                              cur_alt;
  38         u8                              port_num;
  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 = {
  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 = {
  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 = {
  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 = {
 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 = {
 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 = {
 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 = {
 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 = {
 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[] = {
 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 = {
 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 = {
 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[] = {
 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                 dev_dbg(&cdev->gadget->dev,
 203                         "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                         dev_dbg(&cdev->gadget->dev,
 211                                 "reset obex ttyGS%d\n", obex->port_num);
 212                         gserial_disconnect(&obex->port);
 213                 }
 214
 215                 if (!obex->port.in->desc || !obex->port.out->desc) {
 216                         dev_dbg(&cdev->gadget->dev,
 217                                 "init obex ttyGS%d\n", obex->port_num);
 218                         if (config_ep_by_speed(cdev->gadget, f,
 219                                                obex->port.in) ||
 220                             config_ep_by_speed(cdev->gadget, f,
 221                                                obex->port.out)) {
 222                                 obex->port.out->desc = NULL;
 223                                 obex->port.in->desc = NULL;
 224                                 goto fail;
 225                         }
 226                 }
 227
 228                 if (alt == 1) {
 229                         dev_dbg(&cdev->gadget->dev,
 230                                 "activate obex ttyGS%d\n", obex->port_num);
 231                         gserial_connect(&obex->port, obex->port_num);
 232                 }
 233
 234         } else
 235                 goto fail;
 236
 237         obex->cur_alt = alt;
 238
 239         return 0;
 240
 241 fail:
 242         return -EINVAL;
 243 }
 244
 245 static int obex_get_alt(struct usb_function *f, unsigned intf)
 246 {
 247         struct f_obex           *obex = func_to_obex(f);
 248
 249         return obex->cur_alt;
 250 }
 251
 252 static void obex_disable(struct usb_function *f)
 253 {
 254         struct f_obex   *obex = func_to_obex(f);
 255         struct usb_composite_dev *cdev = f->config->cdev;
 256
 257         dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
 258         gserial_disconnect(&obex->port);
 259 }
 260
 261 /*-------------------------------------------------------------------------*/
 262
 263 static void obex_connect(struct gserial *g)
 264 {
 265         struct f_obex           *obex = port_to_obex(g);
 266         struct usb_composite_dev *cdev = g->func.config->cdev;
 267         int                     status;
 268
 269         status = usb_function_activate(&g->func);
 270         if (status)
 271                 dev_dbg(&cdev->gadget->dev,
 272                         "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         status = usb_function_deactivate(&g->func);
 283         if (status)
 284                 dev_dbg(&cdev->gadget->dev,
 285                         "obex ttyGS%d function deactivate --> %d\n",
 286                         obex->port_num, status);
 287 }
 288
 289 /*-------------------------------------------------------------------------*/
 290
 291 /* Some controllers can't support CDC OBEX ... */
 292 static inline bool can_support_obex(struct usb_configuration *c)
 293 {
 294         /* Since the first interface is a NOP, we can ignore the
 295          * issue of multi-interface support on most controllers.
 296          *
 297          * Altsettings are mandatory, however...
 298          */
 299         if (!gadget_is_altset_supported(c->cdev->gadget))
 300                 return false;
 301
 302         /* everything else is *probably* fine ... */
 303         return true;
 304 }
 305
 306 static int obex_bind(struct usb_configuration *c, struct usb_function *f)
 307 {
 308         struct usb_composite_dev *cdev = c->cdev;
 309         struct f_obex           *obex = func_to_obex(f);
 310         struct usb_string       *us;
 311         int                     status;
 312         struct usb_ep           *ep;
 313
 314         if (!can_support_obex(c))
 315                 return -EINVAL;
 316
 317         us = usb_gstrings_attach(cdev, obex_strings,
 318                                  ARRAY_SIZE(obex_string_defs));
 319         if (IS_ERR(us))
 320                 return PTR_ERR(us);
 321         obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
 322         obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
 323         obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
 324
 325         /* allocate instance-specific interface IDs, and patch descriptors */
 326
 327         status = usb_interface_id(c, f);
 328         if (status < 0)
 329                 goto fail;
 330         obex->ctrl_id = status;
 331
 332         obex_control_intf.bInterfaceNumber = status;
 333         obex_cdc_union_desc.bMasterInterface0 = status;
 334
 335         status = usb_interface_id(c, f);
 336         if (status < 0)
 337                 goto fail;
 338         obex->data_id = status;
 339
 340         obex_data_nop_intf.bInterfaceNumber = status;
 341         obex_data_intf.bInterfaceNumber = status;
 342         obex_cdc_union_desc.bSlaveInterface0 = status;
 343
 344         /* allocate instance-specific endpoints */
 345
 346         status = -ENODEV;
 347         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 348         if (!ep)
 349                 goto fail;
 350         obex->port.in = ep;
 351         ep->driver_data = cdev; /* claim */
 352
 353         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 354         if (!ep)
 355                 goto fail;
 356         obex->port.out = ep;
 357         ep->driver_data = cdev; /* claim */
 358
 359         /* support all relevant hardware speeds... we expect that when
 360          * hardware is dual speed, all bulk-capable endpoints work at
 361          * both speeds
 362          */
 363
 364         obex_hs_ep_in_desc.bEndpointAddress =
 365                 obex_fs_ep_in_desc.bEndpointAddress;
 366         obex_hs_ep_out_desc.bEndpointAddress =
 367                 obex_fs_ep_out_desc.bEndpointAddress;
 368
 369         status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
 370         if (status)
 371                 goto fail;
 372
 373         dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 374                 obex->port_num,
 375                 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 376                 obex->port.in->name, obex->port.out->name);
 377
 378         return 0;
 379
 380 fail:
 381         /* we might as well release our claims on endpoints */
 382         if (obex->port.out)
 383                 obex->port.out->driver_data = NULL;
 384         if (obex->port.in)
 385                 obex->port.in->driver_data = NULL;
 386
 387         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 388
 389         return status;
 390 }
 391
 392 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 393 {
 394         return container_of(to_config_group(item), struct f_serial_opts,
 395                             func_inst.group);
 396 }
 397
 398 CONFIGFS_ATTR_STRUCT(f_serial_opts);
 399 static ssize_t f_obex_attr_show(struct config_item *item,
 400                                 struct configfs_attribute *attr,
 401                                 char *page)
 402 {
 403         struct f_serial_opts *opts = to_f_serial_opts(item);
 404         struct f_serial_opts_attribute *f_serial_opts_attr =
 405                 container_of(attr, struct f_serial_opts_attribute, attr);
 406         ssize_t ret = 0;
 407
 408         if (f_serial_opts_attr->show)
 409                 ret = f_serial_opts_attr->show(opts, page);
 410
 411         return ret;
 412 }
 413
 414 static void obex_attr_release(struct config_item *item)
 415 {
 416         struct f_serial_opts *opts = to_f_serial_opts(item);
 417
 418         usb_put_function_instance(&opts->func_inst);
 419 }
 420
 421 static struct configfs_item_operations obex_item_ops = {
 422         .release        = obex_attr_release,
 423         .show_attribute = f_obex_attr_show,
 424 };
 425
 426 static ssize_t f_obex_port_num_show(struct f_serial_opts *opts, char *page)
 427 {
 428         return sprintf(page, "%u\n", opts->port_num);
 429 }
 430
 431 static struct f_serial_opts_attribute f_obex_port_num =
 432         __CONFIGFS_ATTR_RO(port_num, f_obex_port_num_show);
 433
 434 static struct configfs_attribute *acm_attrs[] = {
 435         &f_obex_port_num.attr,
 436         NULL,
 437 };
 438
 439 static struct config_item_type obex_func_type = {
 440         .ct_item_ops    = &obex_item_ops,
 441         .ct_attrs       = acm_attrs,
 442         .ct_owner       = THIS_MODULE,
 443 };
 444
 445 static void obex_free_inst(struct usb_function_instance *f)
 446 {
 447         struct f_serial_opts *opts;
 448
 449         opts = container_of(f, struct f_serial_opts, func_inst);
 450         gserial_free_line(opts->port_num);
 451         kfree(opts);
 452 }
 453
 454 static struct usb_function_instance *obex_alloc_inst(void)
 455 {
 456         struct f_serial_opts *opts;
 457         int ret;
 458
 459         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 460         if (!opts)
 461                 return ERR_PTR(-ENOMEM);
 462
 463         opts->func_inst.free_func_inst = obex_free_inst;
 464         ret = gserial_alloc_line(&opts->port_num);
 465         if (ret) {
 466                 kfree(opts);
 467                 return ERR_PTR(ret);
 468         }
 469         config_group_init_type_name(&opts->func_inst.group, "",
 470                                     &obex_func_type);
 471
 472         return &opts->func_inst;
 473 }
 474
 475 static void obex_free(struct usb_function *f)
 476 {
 477         struct f_obex *obex;
 478
 479         obex = func_to_obex(f);
 480         kfree(obex);
 481 }
 482
 483 static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 484 {
 485         usb_free_all_descriptors(f);
 486 }
 487
 488 static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 489 {
 490         struct f_obex   *obex;
 491         struct f_serial_opts *opts;
 492
 493         /* allocate and initialize one new instance */
 494         obex = kzalloc(sizeof(*obex), GFP_KERNEL);
 495         if (!obex)
 496                 return ERR_PTR(-ENOMEM);
 497
 498         opts = container_of(fi, struct f_serial_opts, func_inst);
 499
 500         obex->port_num = opts->port_num;
 501
 502         obex->port.connect = obex_connect;
 503         obex->port.disconnect = obex_disconnect;
 504
 505         obex->port.func.name = "obex";
 506         /* descriptors are per-instance copies */
 507         obex->port.func.bind = obex_bind;
 508         obex->port.func.unbind = obex_unbind;
 509         obex->port.func.set_alt = obex_set_alt;
 510         obex->port.func.get_alt = obex_get_alt;
 511         obex->port.func.disable = obex_disable;
 512         obex->port.func.free_func = obex_free;
 513         obex->port.func.bind_deactivated = true;
 514
 515         return &obex->port.func;
 516 }
 517
 518 DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 519 MODULE_AUTHOR("Felipe Balbi");
 520 MODULE_LICENSE("GPL");