linux/drivers/usb/gadget/function/f_obex.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * f_obex.c -- USB CDC OBEX function driver
   4 *
   5 * Copyright (C) 2008 Nokia Corporation
   6 * Contact: Felipe Balbi <felipe.balbi@nokia.com>
   7 *
   8 * Based on f_acm.c by Al Borchers and David Brownell.
   9 */
  10
  11/* #define VERBOSE_DEBUG */
  12
  13#include <linux/slab.h>
  14#include <linux/kernel.h>
  15#include <linux/device.h>
  16#include <linux/module.h>
  17
  18#include "u_serial.h"
  19
  20
  21/*
  22 * This CDC OBEX function support just packages a TTY-ish byte stream.
  23 * A user mode server will put it into "raw" mode and handle all the
  24 * relevant protocol details ... this is just a kernel passthrough.
  25 * When possible, we prevent gadget enumeration until that server is
  26 * ready to handle the commands.
  27 */
  28
  29struct f_obex {
  30        struct gserial                  port;
  31        u8                              ctrl_id;
  32        u8                              data_id;
  33        u8                              cur_alt;
  34        u8                              port_num;
  35};
  36
  37static inline struct f_obex *func_to_obex(struct usb_function *f)
  38{
  39        return container_of(f, struct f_obex, port.func);
  40}
  41
  42static inline struct f_obex *port_to_obex(struct gserial *p)
  43{
  44        return container_of(p, struct f_obex, port);
  45}
  46
  47/*-------------------------------------------------------------------------*/
  48
  49#define OBEX_CTRL_IDX   0
  50#define OBEX_DATA_IDX   1
  51
  52static struct usb_string obex_string_defs[] = {
  53        [OBEX_CTRL_IDX].s       = "CDC Object Exchange (OBEX)",
  54        [OBEX_DATA_IDX].s       = "CDC OBEX Data",
  55        {  },   /* end of list */
  56};
  57
  58static struct usb_gadget_strings obex_string_table = {
  59        .language               = 0x0409,       /* en-US */
  60        .strings                = obex_string_defs,
  61};
  62
  63static struct usb_gadget_strings *obex_strings[] = {
  64        &obex_string_table,
  65        NULL,
  66};
  67
  68/*-------------------------------------------------------------------------*/
  69
  70static struct usb_interface_descriptor obex_control_intf = {
  71        .bLength                = sizeof(obex_control_intf),
  72        .bDescriptorType        = USB_DT_INTERFACE,
  73        .bInterfaceNumber       = 0,
  74
  75        .bAlternateSetting      = 0,
  76        .bNumEndpoints          = 0,
  77        .bInterfaceClass        = USB_CLASS_COMM,
  78        .bInterfaceSubClass     = USB_CDC_SUBCLASS_OBEX,
  79};
  80
  81static struct usb_interface_descriptor obex_data_nop_intf = {
  82        .bLength                = sizeof(obex_data_nop_intf),
  83        .bDescriptorType        = USB_DT_INTERFACE,
  84        .bInterfaceNumber       = 1,
  85
  86        .bAlternateSetting      = 0,
  87        .bNumEndpoints          = 0,
  88        .bInterfaceClass        = USB_CLASS_CDC_DATA,
  89};
  90
  91static struct usb_interface_descriptor obex_data_intf = {
  92        .bLength                = sizeof(obex_data_intf),
  93        .bDescriptorType        = USB_DT_INTERFACE,
  94        .bInterfaceNumber       = 2,
  95
  96        .bAlternateSetting      = 1,
  97        .bNumEndpoints          = 2,
  98        .bInterfaceClass        = USB_CLASS_CDC_DATA,
  99};
 100
 101static struct usb_cdc_header_desc obex_cdc_header_desc = {
 102        .bLength                = sizeof(obex_cdc_header_desc),
 103        .bDescriptorType        = USB_DT_CS_INTERFACE,
 104        .bDescriptorSubType     = USB_CDC_HEADER_TYPE,
 105        .bcdCDC                 = cpu_to_le16(0x0120),
 106};
 107
 108static struct usb_cdc_union_desc obex_cdc_union_desc = {
 109        .bLength                = sizeof(obex_cdc_union_desc),
 110        .bDescriptorType        = USB_DT_CS_INTERFACE,
 111        .bDescriptorSubType     = USB_CDC_UNION_TYPE,
 112        .bMasterInterface0      = 1,
 113        .bSlaveInterface0       = 2,
 114};
 115
 116static struct usb_cdc_obex_desc obex_desc = {
 117        .bLength                = sizeof(obex_desc),
 118        .bDescriptorType        = USB_DT_CS_INTERFACE,
 119        .bDescriptorSubType     = USB_CDC_OBEX_TYPE,
 120        .bcdVersion             = cpu_to_le16(0x0100),
 121};
 122
 123/* High-Speed Support */
 124
 125static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
 126        .bLength                = USB_DT_ENDPOINT_SIZE,
 127        .bDescriptorType        = USB_DT_ENDPOINT,
 128
 129        .bEndpointAddress       = USB_DIR_OUT,
 130        .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 131        .wMaxPacketSize         = cpu_to_le16(512),
 132};
 133
 134static struct usb_endpoint_descriptor obex_hs_ep_in_desc = {
 135        .bLength                = USB_DT_ENDPOINT_SIZE,
 136        .bDescriptorType        = USB_DT_ENDPOINT,
 137
 138        .bEndpointAddress       = USB_DIR_IN,
 139        .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 140        .wMaxPacketSize         = cpu_to_le16(512),
 141};
 142
 143static struct usb_descriptor_header *hs_function[] = {
 144        (struct usb_descriptor_header *) &obex_control_intf,
 145        (struct usb_descriptor_header *) &obex_cdc_header_desc,
 146        (struct usb_descriptor_header *) &obex_desc,
 147        (struct usb_descriptor_header *) &obex_cdc_union_desc,
 148
 149        (struct usb_descriptor_header *) &obex_data_nop_intf,
 150        (struct usb_descriptor_header *) &obex_data_intf,
 151        (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
 152        (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
 153        NULL,
 154};
 155
 156/* Full-Speed Support */
 157
 158static struct usb_endpoint_descriptor obex_fs_ep_in_desc = {
 159        .bLength                = USB_DT_ENDPOINT_SIZE,
 160        .bDescriptorType        = USB_DT_ENDPOINT,
 161
 162        .bEndpointAddress       = USB_DIR_IN,
 163        .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 164};
 165
 166static struct usb_endpoint_descriptor obex_fs_ep_out_desc = {
 167        .bLength                = USB_DT_ENDPOINT_SIZE,
 168        .bDescriptorType        = USB_DT_ENDPOINT,
 169
 170        .bEndpointAddress       = USB_DIR_OUT,
 171        .bmAttributes           = USB_ENDPOINT_XFER_BULK,
 172};
 173
 174static struct usb_descriptor_header *fs_function[] = {
 175        (struct usb_descriptor_header *) &obex_control_intf,
 176        (struct usb_descriptor_header *) &obex_cdc_header_desc,
 177        (struct usb_descriptor_header *) &obex_desc,
 178        (struct usb_descriptor_header *) &obex_cdc_union_desc,
 179
 180        (struct usb_descriptor_header *) &obex_data_nop_intf,
 181        (struct usb_descriptor_header *) &obex_data_intf,
 182        (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
 183        (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
 184        NULL,
 185};
 186
 187/*-------------------------------------------------------------------------*/
 188
 189static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 190{
 191        struct f_obex           *obex = func_to_obex(f);
 192        struct usb_composite_dev *cdev = f->config->cdev;
 193
 194        if (intf == obex->ctrl_id) {
 195                if (alt != 0)
 196                        goto fail;
 197                /* NOP */
 198                dev_dbg(&cdev->gadget->dev,
 199                        "reset obex ttyGS%d control\n", obex->port_num);
 200
 201        } else if (intf == obex->data_id) {
 202                if (alt > 1)
 203                        goto fail;
 204
 205                if (obex->port.in->enabled) {
 206                        dev_dbg(&cdev->gadget->dev,
 207                                "reset obex ttyGS%d\n", obex->port_num);
 208                        gserial_disconnect(&obex->port);
 209                }
 210
 211                if (!obex->port.in->desc || !obex->port.out->desc) {
 212                        dev_dbg(&cdev->gadget->dev,
 213                                "init obex ttyGS%d\n", obex->port_num);
 214                        if (config_ep_by_speed(cdev->gadget, f,
 215                                               obex->port.in) ||
 216                            config_ep_by_speed(cdev->gadget, f,
 217                                               obex->port.out)) {
 218                                obex->port.out->desc = NULL;
 219                                obex->port.in->desc = NULL;
 220                                goto fail;
 221                        }
 222                }
 223
 224                if (alt == 1) {
 225                        dev_dbg(&cdev->gadget->dev,
 226                                "activate obex ttyGS%d\n", obex->port_num);
 227                        gserial_connect(&obex->port, obex->port_num);
 228                }
 229
 230        } else
 231                goto fail;
 232
 233        obex->cur_alt = alt;
 234
 235        return 0;
 236
 237fail:
 238        return -EINVAL;
 239}
 240
 241static int obex_get_alt(struct usb_function *f, unsigned intf)
 242{
 243        struct f_obex           *obex = func_to_obex(f);
 244
 245        return obex->cur_alt;
 246}
 247
 248static void obex_disable(struct usb_function *f)
 249{
 250        struct f_obex   *obex = func_to_obex(f);
 251        struct usb_composite_dev *cdev = f->config->cdev;
 252
 253        dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
 254        gserial_disconnect(&obex->port);
 255}
 256
 257/*-------------------------------------------------------------------------*/
 258
 259static void obex_connect(struct gserial *g)
 260{
 261        struct f_obex           *obex = port_to_obex(g);
 262        struct usb_composite_dev *cdev = g->func.config->cdev;
 263        int                     status;
 264
 265        status = usb_function_activate(&g->func);
 266        if (status)
 267                dev_dbg(&cdev->gadget->dev,
 268                        "obex ttyGS%d function activate --> %d\n",
 269                        obex->port_num, status);
 270}
 271
 272static void obex_disconnect(struct gserial *g)
 273{
 274        struct f_obex           *obex = port_to_obex(g);
 275        struct usb_composite_dev *cdev = g->func.config->cdev;
 276        int                     status;
 277
 278        status = usb_function_deactivate(&g->func);
 279        if (status)
 280                dev_dbg(&cdev->gadget->dev,
 281                        "obex ttyGS%d function deactivate --> %d\n",
 282                        obex->port_num, status);
 283}
 284
 285/*-------------------------------------------------------------------------*/
 286
 287/* Some controllers can't support CDC OBEX ... */
 288static inline bool can_support_obex(struct usb_configuration *c)
 289{
 290        /* Since the first interface is a NOP, we can ignore the
 291         * issue of multi-interface support on most controllers.
 292         *
 293         * Altsettings are mandatory, however...
 294         */
 295        if (!gadget_is_altset_supported(c->cdev->gadget))
 296                return false;
 297
 298        /* everything else is *probably* fine ... */
 299        return true;
 300}
 301
 302static int obex_bind(struct usb_configuration *c, struct usb_function *f)
 303{
 304        struct usb_composite_dev *cdev = c->cdev;
 305        struct f_obex           *obex = func_to_obex(f);
 306        struct usb_string       *us;
 307        int                     status;
 308        struct usb_ep           *ep;
 309
 310        if (!can_support_obex(c))
 311                return -EINVAL;
 312
 313        us = usb_gstrings_attach(cdev, obex_strings,
 314                                 ARRAY_SIZE(obex_string_defs));
 315        if (IS_ERR(us))
 316                return PTR_ERR(us);
 317        obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
 318        obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
 319        obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
 320
 321        /* allocate instance-specific interface IDs, and patch descriptors */
 322
 323        status = usb_interface_id(c, f);
 324        if (status < 0)
 325                goto fail;
 326        obex->ctrl_id = status;
 327
 328        obex_control_intf.bInterfaceNumber = status;
 329        obex_cdc_union_desc.bMasterInterface0 = status;
 330
 331        status = usb_interface_id(c, f);
 332        if (status < 0)
 333                goto fail;
 334        obex->data_id = status;
 335
 336        obex_data_nop_intf.bInterfaceNumber = status;
 337        obex_data_intf.bInterfaceNumber = status;
 338        obex_cdc_union_desc.bSlaveInterface0 = status;
 339
 340        /* allocate instance-specific endpoints */
 341
 342        status = -ENODEV;
 343        ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 344        if (!ep)
 345                goto fail;
 346        obex->port.in = ep;
 347
 348        ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 349        if (!ep)
 350                goto fail;
 351        obex->port.out = ep;
 352
 353        /* support all relevant hardware speeds... we expect that when
 354         * hardware is dual speed, all bulk-capable endpoints work at
 355         * both speeds
 356         */
 357
 358        obex_hs_ep_in_desc.bEndpointAddress =
 359                obex_fs_ep_in_desc.bEndpointAddress;
 360        obex_hs_ep_out_desc.bEndpointAddress =
 361                obex_fs_ep_out_desc.bEndpointAddress;
 362
 363        status = usb_assign_descriptors(f, fs_function, hs_function, NULL,
 364                                        NULL);
 365        if (status)
 366                goto fail;
 367
 368        dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 369                obex->port_num,
 370                gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 371                obex->port.in->name, obex->port.out->name);
 372
 373        return 0;
 374
 375fail:
 376        ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 377
 378        return status;
 379}
 380
 381static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 382{
 383        return container_of(to_config_group(item), struct f_serial_opts,
 384                            func_inst.group);
 385}
 386
 387static void obex_attr_release(struct config_item *item)
 388{
 389        struct f_serial_opts *opts = to_f_serial_opts(item);
 390
 391        usb_put_function_instance(&opts->func_inst);
 392}
 393
 394static struct configfs_item_operations obex_item_ops = {
 395        .release        = obex_attr_release,
 396};
 397
 398static ssize_t f_obex_port_num_show(struct config_item *item, char *page)
 399{
 400        return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
 401}
 402
 403CONFIGFS_ATTR_RO(f_obex_, port_num);
 404
 405static struct configfs_attribute *acm_attrs[] = {
 406        &f_obex_attr_port_num,
 407        NULL,
 408};
 409
 410static const struct config_item_type obex_func_type = {
 411        .ct_item_ops    = &obex_item_ops,
 412        .ct_attrs       = acm_attrs,
 413        .ct_owner       = THIS_MODULE,
 414};
 415
 416static void obex_free_inst(struct usb_function_instance *f)
 417{
 418        struct f_serial_opts *opts;
 419
 420        opts = container_of(f, struct f_serial_opts, func_inst);
 421        gserial_free_line(opts->port_num);
 422        kfree(opts);
 423}
 424
 425static struct usb_function_instance *obex_alloc_inst(void)
 426{
 427        struct f_serial_opts *opts;
 428        int ret;
 429
 430        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 431        if (!opts)
 432                return ERR_PTR(-ENOMEM);
 433
 434        opts->func_inst.free_func_inst = obex_free_inst;
 435        ret = gserial_alloc_line_no_console(&opts->port_num);
 436        if (ret) {
 437                kfree(opts);
 438                return ERR_PTR(ret);
 439        }
 440        config_group_init_type_name(&opts->func_inst.group, "",
 441                                    &obex_func_type);
 442
 443        return &opts->func_inst;
 444}
 445
 446static void obex_free(struct usb_function *f)
 447{
 448        struct f_obex *obex;
 449
 450        obex = func_to_obex(f);
 451        kfree(obex);
 452}
 453
 454static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 455{
 456        usb_free_all_descriptors(f);
 457}
 458
 459static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 460{
 461        struct f_obex   *obex;
 462        struct f_serial_opts *opts;
 463
 464        /* allocate and initialize one new instance */
 465        obex = kzalloc(sizeof(*obex), GFP_KERNEL);
 466        if (!obex)
 467                return ERR_PTR(-ENOMEM);
 468
 469        opts = container_of(fi, struct f_serial_opts, func_inst);
 470
 471        obex->port_num = opts->port_num;
 472
 473        obex->port.connect = obex_connect;
 474        obex->port.disconnect = obex_disconnect;
 475
 476        obex->port.func.name = "obex";
 477        /* descriptors are per-instance copies */
 478        obex->port.func.bind = obex_bind;
 479        obex->port.func.unbind = obex_unbind;
 480        obex->port.func.set_alt = obex_set_alt;
 481        obex->port.func.get_alt = obex_get_alt;
 482        obex->port.func.disable = obex_disable;
 483        obex->port.func.free_func = obex_free;
 484        obex->port.func.bind_deactivated = true;
 485
 486        return &obex->port.func;
 487}
 488
 489DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 490MODULE_AUTHOR("Felipe Balbi");
 491MODULE_LICENSE("GPL");
 492