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  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 /* #define VERBOSE_DEBUG */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/utsname.h>
  28 #include <linux/device.h>
  29
  30 #include "u_serial.h"
  31 #include "gadget_chips.h"
  32
  33
  34 /*
  35  * This CDC OBEX function support just packages a TTY-ish byte stream.
  36  * A user mode server will put it into "raw" mode and handle all the
  37  * relevant protocol details ... this is just a kernel passthrough.
  38  *
  39  * REVISIT this driver shouldn't actually activate before that user mode
  40  * server is ready to respond!  When the "serial gadget" utility code
  41  * adds open/close notifications, this driver should use them with new
  42  * (TBS) composite gadget hooks that wrap usb_gadget_disconnect() and
  43  * usb_gadget_connect() calls with refcounts ... disconnect() when we
  44  * bind, then connect() when the user server code is ready to respond.
  45  */
  46
  47 struct obex_ep_descs {
  48         struct usb_endpoint_descriptor  *obex_in;
  49         struct usb_endpoint_descriptor  *obex_out;
  50 };
  51
  52 struct f_obex {
  53         struct gserial                  port;
  54         u8                              ctrl_id;
  55         u8                              data_id;
  56         u8                              port_num;
  57
  58         struct obex_ep_descs            fs;
  59         struct obex_ep_descs            hs;
  60 };
  61
  62 static inline struct f_obex *func_to_obex(struct usb_function *f)
  63 {
  64         return container_of(f, struct f_obex, port.func);
  65 }
  66
  67 /*-------------------------------------------------------------------------*/
  68
  69 #define OBEX_CTRL_IDX   0
  70 #define OBEX_DATA_IDX   1
  71
  72 static struct usb_string obex_string_defs[] = {
  73         [OBEX_CTRL_IDX].s       = "CDC Object Exchange (OBEX)",
  74         [OBEX_DATA_IDX].s       = "CDC OBEX Data",
  75         {  },   /* end of list */
  76 };
  77
  78 static struct usb_gadget_strings obex_string_table = {
  79         .language               = 0x0409,       /* en-US */
  80         .strings                = obex_string_defs,
  81 };
  82
  83 static struct usb_gadget_strings *obex_strings[] = {
  84         &obex_string_table,
  85         NULL,
  86 };
  87
  88 /*-------------------------------------------------------------------------*/
  89
  90 static struct usb_interface_descriptor obex_control_intf __initdata = {
  91         .bLength                = sizeof(obex_control_intf),
  92         .bDescriptorType        = USB_DT_INTERFACE,
  93         .bInterfaceNumber       = 0,
  94
  95         .bAlternateSetting      = 0,
  96         .bNumEndpoints          = 0,
  97         .bInterfaceClass        = USB_CLASS_COMM,
  98         .bInterfaceSubClass     = USB_CDC_SUBCLASS_OBEX,
  99 };
 100
 101 static struct usb_interface_descriptor obex_data_nop_intf __initdata = {
 102         .bLength                = sizeof(obex_data_nop_intf),
 103         .bDescriptorType        = USB_DT_INTERFACE,
 104         .bInterfaceNumber       = 1,
 105
 106         .bAlternateSetting      = 0,
 107         .bNumEndpoints          = 0,
 108         .bInterfaceClass        = USB_CLASS_CDC_DATA,
 109 };
 110
 111 static struct usb_interface_descriptor obex_data_intf __initdata = {
 112         .bLength                = sizeof(obex_data_intf),
 113         .bDescriptorType        = USB_DT_INTERFACE,
 114         .bInterfaceNumber       = 2,
 115
 116         .bAlternateSetting      = 1,
 117         .bNumEndpoints          = 2,
 118         .bInterfaceClass        = USB_CLASS_CDC_DATA,
 119 };
 120
 121 static struct usb_cdc_header_desc obex_cdc_header_desc __initdata = {
 122         .bLength                = sizeof(obex_cdc_header_desc),
 123         .bDescriptorType        = USB_DT_CS_INTERFACE,
 124         .bDescriptorSubType     = USB_CDC_HEADER_TYPE,
 125         .bcdCDC                 = __constant_cpu_to_le16(0x0120),
 126 };
 127
 128 static struct usb_cdc_union_desc obex_cdc_union_desc __initdata = {
 129         .bLength                = sizeof(obex_cdc_union_desc),
 130         .bDescriptorType        = USB_DT_CS_INTERFACE,
 131         .bDescriptorSubType     = USB_CDC_UNION_TYPE,
 132         .bMasterInterface0      = 1,
 133         .bSlaveInterface0       = 2,
 134 };
 135
 136 static struct usb_cdc_obex_desc obex_desc __initdata = {
 137         .bLength                = sizeof(obex_desc),
 138         .bDescriptorType        = USB_DT_CS_INTERFACE,
 139         .bDescriptorSubType     = USB_CDC_OBEX_TYPE,
 140         .bcdVersion             = __constant_cpu_to_le16(0x0100),
 141 };
 142
 143 /* High-Speed Support */
 144
 145 static struct usb_endpoint_descriptor obex_hs_ep_out_desc __initdata = {
 146         .bLength                = USB_DT_ENDPOINT_SIZE,
 147         .bDescriptorType        = USB_DT_ENDPOINT,
 148
 149         .bEndpointAddress       = USB_DIR_OUT,
 150         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 151         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 152 };
 153
 154 static struct usb_endpoint_descriptor obex_hs_ep_in_desc __initdata = {
 155         .bLength                = USB_DT_ENDPOINT_SIZE,
 156         .bDescriptorType        = USB_DT_ENDPOINT,
 157
 158         .bEndpointAddress       = USB_DIR_IN,
 159         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 160         .wMaxPacketSize         = __constant_cpu_to_le16(512),
 161 };
 162
 163 static struct usb_descriptor_header *hs_function[] __initdata = {
 164         (struct usb_descriptor_header *) &obex_control_intf,
 165         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 166         (struct usb_descriptor_header *) &obex_desc,
 167         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 168
 169         (struct usb_descriptor_header *) &obex_data_nop_intf,
 170         (struct usb_descriptor_header *) &obex_data_intf,
 171         (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
 172         (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
 173         NULL,
 174 };
 175
 176 /* Full-Speed Support */
 177
 178 static struct usb_endpoint_descriptor obex_fs_ep_in_desc __initdata = {
 179         .bLength                = USB_DT_ENDPOINT_SIZE,
 180         .bDescriptorType        = USB_DT_ENDPOINT,
 181
 182         .bEndpointAddress       = USB_DIR_IN,
 183         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 184 };
 185
 186 static struct usb_endpoint_descriptor obex_fs_ep_out_desc __initdata = {
 187         .bLength                = USB_DT_ENDPOINT_SIZE,
 188         .bDescriptorType        = USB_DT_ENDPOINT,
 189
 190         .bEndpointAddress       = USB_DIR_OUT,
 191         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 192 };
 193
 194 static struct usb_descriptor_header *fs_function[] __initdata = {
 195         (struct usb_descriptor_header *) &obex_control_intf,
 196         (struct usb_descriptor_header *) &obex_cdc_header_desc,
 197         (struct usb_descriptor_header *) &obex_desc,
 198         (struct usb_descriptor_header *) &obex_cdc_union_desc,
 199
 200         (struct usb_descriptor_header *) &obex_data_nop_intf,
 201         (struct usb_descriptor_header *) &obex_data_intf,
 202         (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
 203         (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
 204         NULL,
 205 };
 206
 207 /*-------------------------------------------------------------------------*/
 208
 209 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 210 {
 211         struct f_obex           *obex = func_to_obex(f);
 212         struct usb_composite_dev *cdev = f->config->cdev;
 213
 214         if (intf == obex->ctrl_id) {
 215                 if (alt != 0)
 216                         goto fail;
 217                 /* NOP */
 218                 DBG(cdev, "reset obex ttyGS%d control\n", obex->port_num);
 219
 220         } else if (intf == obex->data_id) {
 221                 if (alt > 1)
 222                         goto fail;
 223
 224                 if (obex->port.in->driver_data) {
 225                         DBG(cdev, "reset obex ttyGS%d\n", obex->port_num);
 226                         gserial_disconnect(&obex->port);
 227                 }
 228
 229                 if (!obex->port.in_desc) {
 230                         DBG(cdev, "init obex ttyGS%d\n", obex->port_num);
 231                         obex->port.in_desc = ep_choose(cdev->gadget,
 232                                         obex->hs.obex_in, obex->fs.obex_in);
 233                         obex->port.out_desc = ep_choose(cdev->gadget,
 234                                         obex->hs.obex_out, obex->fs.obex_out);
 235                 }
 236
 237                 if (alt == 1) {
 238                         DBG(cdev, "activate obex ttyGS%d\n", obex->port_num);
 239                         gserial_connect(&obex->port, obex->port_num);
 240                 }
 241
 242         } else
 243                 goto fail;
 244
 245         return 0;
 246
 247 fail:
 248         return -EINVAL;
 249 }
 250
 251 static int obex_get_alt(struct usb_function *f, unsigned intf)
 252 {
 253         struct f_obex           *obex = func_to_obex(f);
 254
 255         if (intf == obex->ctrl_id)
 256                 return 0;
 257
 258         return obex->port.in->driver_data ? 1 : 0;
 259 }
 260
 261 static void obex_disable(struct usb_function *f)
 262 {
 263         struct f_obex   *obex = func_to_obex(f);
 264         struct usb_composite_dev *cdev = f->config->cdev;
 265
 266         DBG(cdev, "obex ttyGS%d disable\n", obex->port_num);
 267         gserial_disconnect(&obex->port);
 268 }
 269
 270 /*-------------------------------------------------------------------------*/
 271
 272 static int __init
 273 obex_bind(struct usb_configuration *c, struct usb_function *f)
 274 {
 275         struct usb_composite_dev *cdev = c->cdev;
 276         struct f_obex           *obex = func_to_obex(f);
 277         int                     status;
 278         struct usb_ep           *ep;
 279
 280         /* allocate instance-specific interface IDs, and patch descriptors */
 281
 282         status = usb_interface_id(c, f);
 283         if (status < 0)
 284                 goto fail;
 285         obex->ctrl_id = status;
 286
 287         obex_control_intf.bInterfaceNumber = status;
 288         obex_cdc_union_desc.bMasterInterface0 = status;
 289
 290         status = usb_interface_id(c, f);
 291         if (status < 0)
 292                 goto fail;
 293         obex->data_id = status;
 294
 295         obex_data_nop_intf.bInterfaceNumber = status;
 296         obex_data_intf.bInterfaceNumber = status;
 297         obex_cdc_union_desc.bSlaveInterface0 = status;
 298
 299         /* allocate instance-specific endpoints */
 300
 301         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 302         if (!ep)
 303                 goto fail;
 304         obex->port.in = ep;
 305         ep->driver_data = cdev; /* claim */
 306
 307         ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 308         if (!ep)
 309                 goto fail;
 310         obex->port.out = ep;
 311         ep->driver_data = cdev; /* claim */
 312
 313         /* copy descriptors, and track endpoint copies */
 314         f->descriptors = usb_copy_descriptors(fs_function);
 315
 316         obex->fs.obex_in = usb_find_endpoint(fs_function,
 317                         f->descriptors, &obex_fs_ep_in_desc);
 318         obex->fs.obex_out = usb_find_endpoint(fs_function,
 319                         f->descriptors, &obex_fs_ep_out_desc);
 320
 321         /* support all relevant hardware speeds... we expect that when
 322          * hardware is dual speed, all bulk-capable endpoints work at
 323          * both speeds
 324          */
 325         if (gadget_is_dualspeed(c->cdev->gadget)) {
 326
 327                 obex_hs_ep_in_desc.bEndpointAddress =
 328                                 obex_fs_ep_in_desc.bEndpointAddress;
 329                 obex_hs_ep_out_desc.bEndpointAddress =
 330                                 obex_fs_ep_out_desc.bEndpointAddress;
 331
 332                 /* copy descriptors, and track endpoint copies */
 333                 f->hs_descriptors = usb_copy_descriptors(hs_function);
 334
 335                 obex->hs.obex_in = usb_find_endpoint(hs_function,
 336                                 f->descriptors, &obex_hs_ep_in_desc);
 337                 obex->hs.obex_out = usb_find_endpoint(hs_function,
 338                                 f->descriptors, &obex_hs_ep_out_desc);
 339         }
 340
 341         DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 342                         obex->port_num,
 343                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 344                         obex->port.in->name, obex->port.out->name);
 345
 346         return 0;
 347
 348 fail:
 349         /* we might as well release our claims on endpoints */
 350         if (obex->port.out)
 351                 obex->port.out->driver_data = NULL;
 352         if (obex->port.in)
 353                 obex->port.in->driver_data = NULL;
 354
 355         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 356
 357         return status;
 358 }
 359
 360 static void
 361 obex_unbind(struct usb_configuration *c, struct usb_function *f)
 362 {
 363         if (gadget_is_dualspeed(c->cdev->gadget))
 364                 usb_free_descriptors(f->hs_descriptors);
 365         usb_free_descriptors(f->descriptors);
 366         kfree(func_to_obex(f));
 367 }
 368
 369 /* Some controllers can't support CDC OBEX ... */
 370 static inline bool can_support_obex(struct usb_configuration *c)
 371 {
 372         /* Since the first interface is a NOP, we can ignore the
 373          * issue of multi-interface support on most controllers.
 374          *
 375          * Altsettings are mandatory, however...
 376          */
 377         if (!gadget_supports_altsettings(c->cdev->gadget))
 378                 return false;
 379
 380         /* everything else is *probably* fine ... */
 381         return true;
 382 }
 383
 384 /**
 385  * obex_bind_config - add a CDC OBEX function to a configuration
 386  * @c: the configuration to support the CDC OBEX instance
 387  * @port_num: /dev/ttyGS* port this interface will use
 388  * Context: single threaded during gadget setup
 389  *
 390  * Returns zero on success, else negative errno.
 391  *
 392  * Caller must have called @gserial_setup() with enough ports to
 393  * handle all the ones it binds.  Caller is also responsible
 394  * for calling @gserial_cleanup() before module unload.
 395  */
 396 int __init obex_bind_config(struct usb_configuration *c, u8 port_num)
 397 {
 398         struct f_obex   *obex;
 399         int             status;
 400
 401         if (!can_support_obex(c))
 402                 return -EINVAL;
 403
 404         /* maybe allocate device-global string IDs, and patch descriptors */
 405         if (obex_string_defs[OBEX_CTRL_IDX].id == 0) {
 406                 status = usb_string_id(c->cdev);
 407                 if (status < 0)
 408                         return status;
 409                 obex_string_defs[OBEX_CTRL_IDX].id = status;
 410
 411                 obex_control_intf.iInterface = status;
 412
 413                 status = usb_string_id(c->cdev);
 414                 if (status < 0)
 415                         return status;
 416                 obex_string_defs[OBEX_DATA_IDX].id = status;
 417
 418                 obex_data_nop_intf.iInterface =
 419                         obex_data_intf.iInterface = status;
 420         }
 421
 422         /* allocate and initialize one new instance */
 423         obex = kzalloc(sizeof *obex, GFP_KERNEL);
 424         if (!obex)
 425                 return -ENOMEM;
 426
 427         obex->port_num = port_num;
 428
 429         obex->port.func.name = "obex";
 430         obex->port.func.strings = obex_strings;
 431         /* descriptors are per-instance copies */
 432         obex->port.func.bind = obex_bind;
 433         obex->port.func.unbind = obex_unbind;
 434         obex->port.func.set_alt = obex_set_alt;
 435         obex->port.func.get_alt = obex_get_alt;
 436         obex->port.func.disable = obex_disable;
 437
 438         status = usb_add_function(c, &obex->port.func);
 439         if (status)
 440                 kfree(obex);
 441
 442         return status;
 443 }
 444
 445 MODULE_AUTHOR("Felipe Balbi");
 446 MODULE_LICENSE("GPL");