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 __initdata = {
  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 __initdata = {
  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 __initdata = {
  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 __initdata = {
 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 __initdata = {
 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 __initdata = {
 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 __initdata = {
 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 __initdata = {
 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[] __initdata = {
 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 __initdata = {
 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 __initdata = {
 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[] __initdata = {
 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 static int __init
 294 obex_bind(struct usb_configuration *c, struct usb_function *f)
 295 {
 296         struct usb_composite_dev *cdev = c->cdev;
 297         struct f_obex           *obex = func_to_obex(f);
 298         int                     status;
 299         struct usb_ep           *ep;
 300
 301         /* allocate instance-specific interface IDs, and patch descriptors */
 302
 303         status = usb_interface_id(c, f);
 304         if (status < 0)
 305                 goto fail;
 306         obex->ctrl_id = status;
 307
 308         obex_control_intf.bInterfaceNumber = status;
 309         obex_cdc_union_desc.bMasterInterface0 = status;
 310
 311         status = usb_interface_id(c, f);
 312         if (status < 0)
 313                 goto fail;
 314         obex->data_id = status;
 315
 316         obex_data_nop_intf.bInterfaceNumber = status;
 317         obex_data_intf.bInterfaceNumber = status;
 318         obex_cdc_union_desc.bSlaveInterface0 = status;
 319
 320         /* allocate instance-specific endpoints */
 321
 322         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 323         if (!ep)
 324                 goto fail;
 325         obex->port.in = ep;
 326         ep->driver_data = cdev; /* claim */
 327
 328         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 329         if (!ep)
 330                 goto fail;
 331         obex->port.out = ep;
 332         ep->driver_data = cdev; /* claim */
 333
 334         /* support all relevant hardware speeds... we expect that when
 335          * hardware is dual speed, all bulk-capable endpoints work at
 336          * both speeds
 337          */
 338
 339         obex_hs_ep_in_desc.bEndpointAddress =
 340                 obex_fs_ep_in_desc.bEndpointAddress;
 341         obex_hs_ep_out_desc.bEndpointAddress =
 342                 obex_fs_ep_out_desc.bEndpointAddress;
 343
 344         status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
 345         if (status)
 346                 goto fail;
 347
 348         /* Avoid letting this gadget enumerate until the userspace
 349          * OBEX server is active.
 350          */
 351         status = usb_function_deactivate(f);
 352         if (status < 0)
 353                 WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
 354                         obex->port_num, status);
 355         else
 356                 obex->can_activate = true;
 357
 358
 359         DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 360                         obex->port_num,
 361                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 362                         obex->port.in->name, obex->port.out->name);
 363
 364         return 0;
 365
 366 fail:
 367         usb_free_all_descriptors(f);
 368         /* we might as well release our claims on endpoints */
 369         if (obex->port.out)
 370                 obex->port.out->driver_data = NULL;
 371         if (obex->port.in)
 372                 obex->port.in->driver_data = NULL;
 373
 374         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 375
 376         return status;
 377 }
 378
 379 static void
 380 obex_unbind(struct usb_configuration *c, struct usb_function *f)
 381 {
 382         obex_string_defs[OBEX_CTRL_IDX].id = 0;
 383         usb_free_all_descriptors(f);
 384         kfree(func_to_obex(f));
 385 }
 386
 387 /* Some controllers can't support CDC OBEX ... */
 388 static inline bool can_support_obex(struct usb_configuration *c)
 389 {
 390         /* Since the first interface is a NOP, we can ignore the
 391          * issue of multi-interface support on most controllers.
 392          *
 393          * Altsettings are mandatory, however...
 394          */
 395         if (!gadget_supports_altsettings(c->cdev->gadget))
 396                 return false;
 397
 398         /* everything else is *probably* fine ... */
 399         return true;
 400 }
 401
 402 /**
 403  * obex_bind_config - add a CDC OBEX function to a configuration
 404  * @c: the configuration to support the CDC OBEX instance
 405  * @port_num: /dev/ttyGS* port this interface will use
 406  * Context: single threaded during gadget setup
 407  *
 408  * Returns zero on success, else negative errno.
 409  *
 410  * Caller must have called @gserial_setup() with enough ports to
 411  * handle all the ones it binds.  Caller is also responsible
 412  * for calling @gserial_cleanup() before module unload.
 413  */
 414 int __init obex_bind_config(struct usb_configuration *c, u8 port_num)
 415 {
 416         struct f_obex   *obex;
 417         int             status;
 418
 419         if (!can_support_obex(c))
 420                 return -EINVAL;
 421
 422         if (obex_string_defs[OBEX_CTRL_IDX].id == 0) {
 423                 status = usb_string_ids_tab(c->cdev, obex_string_defs);
 424                 if (status < 0)
 425                         return status;
 426                 obex_control_intf.iInterface =
 427                         obex_string_defs[OBEX_CTRL_IDX].id;
 428
 429                 status = obex_string_defs[OBEX_DATA_IDX].id;
 430                 obex_data_nop_intf.iInterface = status;
 431                 obex_data_intf.iInterface = status;
 432         }
 433
 434         /* allocate and initialize one new instance */
 435         obex = kzalloc(sizeof *obex, GFP_KERNEL);
 436         if (!obex)
 437                 return -ENOMEM;
 438
 439         obex->port_num = port_num;
 440
 441         obex->port.connect = obex_connect;
 442         obex->port.disconnect = obex_disconnect;
 443
 444         obex->port.func.name = "obex";
 445         obex->port.func.strings = obex_strings;
 446         /* descriptors are per-instance copies */
 447         obex->port.func.bind = obex_bind;
 448         obex->port.func.unbind = obex_unbind;
 449         obex->port.func.set_alt = obex_set_alt;
 450         obex->port.func.get_alt = obex_get_alt;
 451         obex->port.func.disable = obex_disable;
 452
 453         status = usb_add_function(c, &obex->port.func);
 454         if (status)
 455                 kfree(obex);
 456
 457         return status;
 458 }
 459
 460 MODULE_AUTHOR("Felipe Balbi");
 461 MODULE_LICENSE("GPL");