linux/drivers/usb/gadget/function/f_obex.c
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   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
  33struct f_obex {
  34        struct gserial                  port;
  35        u8                              ctrl_id;
  36        u8                              data_id;
  37        u8                              cur_alt;
  38        u8                              port_num;
  39};
  40
  41static inline struct f_obex *func_to_obex(struct usb_function *f)
  42{
  43        return container_of(f, struct f_obex, port.func);
  44}
  45
  46static 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
  56static 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
  62static struct usb_gadget_strings obex_string_table = {
  63        .language               = 0x0409,       /* en-US */
  64        .strings                = obex_string_defs,
  65};
  66
  67static struct usb_gadget_strings *obex_strings[] = {
  68        &obex_string_table,
  69        NULL,
  70};
  71
  72/*-------------------------------------------------------------------------*/
  73
  74static 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
  85static 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
  95static 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
 105static 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
 112static 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
 120static 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
 129static 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
 138static 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
 147static 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
 162static 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
 170static 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
 178static 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
 193static 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->enabled) {
 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
 241fail:
 242        return -EINVAL;
 243}
 244
 245static 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
 252static 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
 263static 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
 276static 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 ... */
 292static 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
 306static 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
 352        ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 353        if (!ep)
 354                goto fail;
 355        obex->port.out = ep;
 356
 357        /* support all relevant hardware speeds... we expect that when
 358         * hardware is dual speed, all bulk-capable endpoints work at
 359         * both speeds
 360         */
 361
 362        obex_hs_ep_in_desc.bEndpointAddress =
 363                obex_fs_ep_in_desc.bEndpointAddress;
 364        obex_hs_ep_out_desc.bEndpointAddress =
 365                obex_fs_ep_out_desc.bEndpointAddress;
 366
 367        status = usb_assign_descriptors(f, fs_function, hs_function, NULL,
 368                                        NULL);
 369        if (status)
 370                goto fail;
 371
 372        dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 373                obex->port_num,
 374                gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 375                obex->port.in->name, obex->port.out->name);
 376
 377        return 0;
 378
 379fail:
 380        ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 381
 382        return status;
 383}
 384
 385static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 386{
 387        return container_of(to_config_group(item), struct f_serial_opts,
 388                            func_inst.group);
 389}
 390
 391static void obex_attr_release(struct config_item *item)
 392{
 393        struct f_serial_opts *opts = to_f_serial_opts(item);
 394
 395        usb_put_function_instance(&opts->func_inst);
 396}
 397
 398static struct configfs_item_operations obex_item_ops = {
 399        .release        = obex_attr_release,
 400};
 401
 402static ssize_t f_obex_port_num_show(struct config_item *item, char *page)
 403{
 404        return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
 405}
 406
 407CONFIGFS_ATTR_RO(f_obex_, port_num);
 408
 409static struct configfs_attribute *acm_attrs[] = {
 410        &f_obex_attr_port_num,
 411        NULL,
 412};
 413
 414static struct config_item_type obex_func_type = {
 415        .ct_item_ops    = &obex_item_ops,
 416        .ct_attrs       = acm_attrs,
 417        .ct_owner       = THIS_MODULE,
 418};
 419
 420static void obex_free_inst(struct usb_function_instance *f)
 421{
 422        struct f_serial_opts *opts;
 423
 424        opts = container_of(f, struct f_serial_opts, func_inst);
 425        gserial_free_line(opts->port_num);
 426        kfree(opts);
 427}
 428
 429static struct usb_function_instance *obex_alloc_inst(void)
 430{
 431        struct f_serial_opts *opts;
 432        int ret;
 433
 434        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 435        if (!opts)
 436                return ERR_PTR(-ENOMEM);
 437
 438        opts->func_inst.free_func_inst = obex_free_inst;
 439        ret = gserial_alloc_line(&opts->port_num);
 440        if (ret) {
 441                kfree(opts);
 442                return ERR_PTR(ret);
 443        }
 444        config_group_init_type_name(&opts->func_inst.group, "",
 445                                    &obex_func_type);
 446
 447        return &opts->func_inst;
 448}
 449
 450static void obex_free(struct usb_function *f)
 451{
 452        struct f_obex *obex;
 453
 454        obex = func_to_obex(f);
 455        kfree(obex);
 456}
 457
 458static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 459{
 460        usb_free_all_descriptors(f);
 461}
 462
 463static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 464{
 465        struct f_obex   *obex;
 466        struct f_serial_opts *opts;
 467
 468        /* allocate and initialize one new instance */
 469        obex = kzalloc(sizeof(*obex), GFP_KERNEL);
 470        if (!obex)
 471                return ERR_PTR(-ENOMEM);
 472
 473        opts = container_of(fi, struct f_serial_opts, func_inst);
 474
 475        obex->port_num = opts->port_num;
 476
 477        obex->port.connect = obex_connect;
 478        obex->port.disconnect = obex_disconnect;
 479
 480        obex->port.func.name = "obex";
 481        /* descriptors are per-instance copies */
 482        obex->port.func.bind = obex_bind;
 483        obex->port.func.unbind = obex_unbind;
 484        obex->port.func.set_alt = obex_set_alt;
 485        obex->port.func.get_alt = obex_get_alt;
 486        obex->port.func.disable = obex_disable;
 487        obex->port.func.free_func = obex_free;
 488        obex->port.func.bind_deactivated = true;
 489
 490        return &obex->port.func;
 491}
 492
 493DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 494MODULE_AUTHOR("Felipe Balbi");
 495MODULE_LICENSE("GPL");
 496