linux/drivers/uwb/hwa-rc.c
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   1/*
   2 * WUSB Host Wire Adapter: Radio Control Interface (WUSB[8.6])
   3 * Radio Control command/event transport
   4 *
   5 * Copyright (C) 2005-2006 Intel Corporation
   6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License version
  10 * 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 * 02110-1301, USA.
  21 *
  22 *
  23 * Initialize the Radio Control interface Driver.
  24 *
  25 * For each device probed, creates an 'struct hwarc' which contains
  26 * just the representation of the UWB Radio Controller, and the logic
  27 * for reading notifications and passing them to the UWB Core.
  28 *
  29 * So we initialize all of those, register the UWB Radio Controller
  30 * and setup the notification/event handle to pipe the notifications
  31 * to the UWB management Daemon.
  32 *
  33 * Command and event filtering.
  34 *
  35 * This is the driver for the Radio Control Interface described in WUSB
  36 * 1.0. The core UWB module assumes that all drivers are compliant to the
  37 * WHCI 0.95 specification. We thus create a filter that parses all
  38 * incoming messages from the (WUSB 1.0) device and manipulate them to
  39 * conform to the WHCI 0.95 specification. Similarly, outgoing messages
  40 * are parsed and manipulated to conform to the WUSB 1.0 compliant messages
  41 * that the device expects. Only a few messages are affected:
  42 * Affected events:
  43 *    UWB_RC_EVT_BEACON
  44 *    UWB_RC_EVT_BP_SLOT_CHANGE
  45 *    UWB_RC_EVT_DRP_AVAIL
  46 *    UWB_RC_EVT_DRP
  47 * Affected commands:
  48 *    UWB_RC_CMD_SCAN
  49 *    UWB_RC_CMD_SET_DRP_IE
  50 *
  51 *
  52 *
  53 */
  54#include <linux/init.h>
  55#include <linux/module.h>
  56#include <linux/slab.h>
  57#include <linux/usb.h>
  58#include <linux/usb/wusb.h>
  59#include <linux/usb/wusb-wa.h>
  60#include <linux/uwb.h>
  61
  62#include "uwb-internal.h"
  63
  64/* The device uses commands and events from the WHCI specification, although
  65 * reporting itself as WUSB compliant. */
  66#define WUSB_QUIRK_WHCI_CMD_EVT         0x01
  67
  68/**
  69 * Descriptor for an instance of the UWB Radio Control Driver that
  70 * attaches to the RCI interface of the Host Wired Adapter.
  71 *
  72 * Unless there is a lock specific to the 'data members', all access
  73 * is protected by uwb_rc->mutex.
  74 *
  75 * The NEEP (Notification/Event EndPoint) URB (@neep_urb) writes to
  76 * @rd_buffer. Note there is no locking because it is perfectly (heh!)
  77 * serialized--probe() submits an URB, callback is called, processes
  78 * the data (synchronously), submits another URB, and so on. There is
  79 * no concurrent access to the buffer.
  80 */
  81struct hwarc {
  82        struct usb_device *usb_dev;
  83        struct usb_interface *usb_iface;
  84        struct uwb_rc *uwb_rc;          /* UWB host controller */
  85        struct urb *neep_urb;           /* Notification endpoint handling */
  86        struct edc neep_edc;
  87        void *rd_buffer;                /* NEEP read buffer */
  88};
  89
  90
  91/* Beacon received notification (WUSB 1.0 [8.6.3.2]) */
  92struct uwb_rc_evt_beacon_WUSB_0100 {
  93        struct uwb_rceb rceb;
  94        u8      bChannelNumber;
  95        __le16  wBPSTOffset;
  96        u8      bLQI;
  97        u8      bRSSI;
  98        __le16  wBeaconInfoLength;
  99        u8      BeaconInfo[];
 100} __attribute__((packed));
 101
 102/**
 103 * Filter WUSB 1.0 BEACON RCV notification to be WHCI 0.95
 104 *
 105 * @header: the incoming event
 106 * @buf_size: size of buffer containing incoming event
 107 * @new_size: size of event after filtering completed
 108 *
 109 * The WHCI 0.95 spec has a "Beacon Type" field. This value is unknown at
 110 * the time we receive the beacon from WUSB so we just set it to
 111 * UWB_RC_BEACON_TYPE_NEIGHBOR as a default.
 112 * The solution below allocates memory upon receipt of every beacon from a
 113 * WUSB device. This will deteriorate performance. What is the right way to
 114 * do this?
 115 */
 116static
 117int hwarc_filter_evt_beacon_WUSB_0100(struct uwb_rc *rc,
 118                                      struct uwb_rceb **header,
 119                                      const size_t buf_size,
 120                                      size_t *new_size)
 121{
 122        struct uwb_rc_evt_beacon_WUSB_0100 *be;
 123        struct uwb_rc_evt_beacon *newbe;
 124        size_t bytes_left, ielength;
 125        struct device *dev = &rc->uwb_dev.dev;
 126
 127        be = container_of(*header, struct uwb_rc_evt_beacon_WUSB_0100, rceb);
 128        bytes_left = buf_size;
 129        if (bytes_left < sizeof(*be)) {
 130                dev_err(dev, "Beacon Received Notification: Not enough data "
 131                        "to decode for filtering (%zu vs %zu bytes needed)\n",
 132                        bytes_left, sizeof(*be));
 133                return -EINVAL;
 134        }
 135        bytes_left -= sizeof(*be);
 136        ielength = le16_to_cpu(be->wBeaconInfoLength);
 137        if (bytes_left < ielength) {
 138                dev_err(dev, "Beacon Received Notification: Not enough data "
 139                        "to decode IEs (%zu vs %zu bytes needed)\n",
 140                        bytes_left, ielength);
 141                return -EINVAL;
 142        }
 143        newbe = kzalloc(sizeof(*newbe) + ielength, GFP_ATOMIC);
 144        if (newbe == NULL)
 145                return -ENOMEM;
 146        newbe->rceb = be->rceb;
 147        newbe->bChannelNumber = be->bChannelNumber;
 148        newbe->bBeaconType = UWB_RC_BEACON_TYPE_NEIGHBOR;
 149        newbe->wBPSTOffset = be->wBPSTOffset;
 150        newbe->bLQI = be->bLQI;
 151        newbe->bRSSI = be->bRSSI;
 152        newbe->wBeaconInfoLength = be->wBeaconInfoLength;
 153        memcpy(newbe->BeaconInfo, be->BeaconInfo, ielength);
 154        *header = &newbe->rceb;
 155        *new_size = sizeof(*newbe) + ielength;
 156        return 1;  /* calling function will free memory */
 157}
 158
 159
 160/* DRP Availability change notification (WUSB 1.0 [8.6.3.8]) */
 161struct uwb_rc_evt_drp_avail_WUSB_0100 {
 162        struct uwb_rceb rceb;
 163        __le16 wIELength;
 164        u8 IEData[];
 165} __attribute__((packed));
 166
 167/**
 168 * Filter WUSB 1.0 DRP AVAILABILITY CHANGE notification to be WHCI 0.95
 169 *
 170 * @header: the incoming event
 171 * @buf_size: size of buffer containing incoming event
 172 * @new_size: size of event after filtering completed
 173 */
 174static
 175int hwarc_filter_evt_drp_avail_WUSB_0100(struct uwb_rc *rc,
 176                                         struct uwb_rceb **header,
 177                                         const size_t buf_size,
 178                                         size_t *new_size)
 179{
 180        struct uwb_rc_evt_drp_avail_WUSB_0100 *da;
 181        struct uwb_rc_evt_drp_avail *newda;
 182        struct uwb_ie_hdr *ie_hdr;
 183        size_t bytes_left, ielength;
 184        struct device *dev = &rc->uwb_dev.dev;
 185
 186
 187        da = container_of(*header, struct uwb_rc_evt_drp_avail_WUSB_0100, rceb);
 188        bytes_left = buf_size;
 189        if (bytes_left < sizeof(*da)) {
 190                dev_err(dev, "Not enough data to decode DRP Avail "
 191                        "Notification for filtering. Expected %zu, "
 192                        "received %zu.\n", (size_t)sizeof(*da), bytes_left);
 193                return -EINVAL;
 194        }
 195        bytes_left -= sizeof(*da);
 196        ielength = le16_to_cpu(da->wIELength);
 197        if (bytes_left < ielength) {
 198                dev_err(dev, "DRP Avail Notification filter: IE length "
 199                        "[%zu bytes] does not match actual length "
 200                        "[%zu bytes].\n", ielength, bytes_left);
 201                return -EINVAL;
 202        }
 203        if (ielength < sizeof(*ie_hdr)) {
 204                dev_err(dev, "DRP Avail Notification filter: Not enough "
 205                        "data to decode IE [%zu bytes, %zu needed]\n",
 206                        ielength, sizeof(*ie_hdr));
 207                return -EINVAL;
 208        }
 209        ie_hdr = (void *) da->IEData;
 210        if (ie_hdr->length > 32) {
 211                dev_err(dev, "DRP Availability Change event has unexpected "
 212                        "length for filtering. Expected < 32 bytes, "
 213                        "got %zu bytes.\n", (size_t)ie_hdr->length);
 214                return -EINVAL;
 215        }
 216        newda = kzalloc(sizeof(*newda), GFP_ATOMIC);
 217        if (newda == NULL)
 218                return -ENOMEM;
 219        newda->rceb = da->rceb;
 220        memcpy(newda->bmp, (u8 *) ie_hdr + sizeof(*ie_hdr), ie_hdr->length);
 221        *header = &newda->rceb;
 222        *new_size = sizeof(*newda);
 223        return 1; /* calling function will free memory */
 224}
 225
 226
 227/* DRP notification (WUSB 1.0 [8.6.3.9]) */
 228struct uwb_rc_evt_drp_WUSB_0100 {
 229        struct uwb_rceb rceb;
 230        struct uwb_dev_addr wSrcAddr;
 231        u8 bExplicit;
 232        __le16 wIELength;
 233        u8 IEData[];
 234} __attribute__((packed));
 235
 236/**
 237 * Filter WUSB 1.0 DRP Notification to be WHCI 0.95
 238 *
 239 * @header: the incoming event
 240 * @buf_size: size of buffer containing incoming event
 241 * @new_size: size of event after filtering completed
 242 *
 243 * It is hard to manage DRP reservations without having a Reason code.
 244 * Unfortunately there is none in the WUSB spec. We just set the default to
 245 * DRP IE RECEIVED.
 246 * We do not currently use the bBeaconSlotNumber value, so we set this to
 247 * zero for now.
 248 */
 249static
 250int hwarc_filter_evt_drp_WUSB_0100(struct uwb_rc *rc,
 251                                   struct uwb_rceb **header,
 252                                   const size_t buf_size,
 253                                   size_t *new_size)
 254{
 255        struct uwb_rc_evt_drp_WUSB_0100 *drpev;
 256        struct uwb_rc_evt_drp *newdrpev;
 257        size_t bytes_left, ielength;
 258        struct device *dev = &rc->uwb_dev.dev;
 259
 260        drpev = container_of(*header, struct uwb_rc_evt_drp_WUSB_0100, rceb);
 261        bytes_left = buf_size;
 262        if (bytes_left < sizeof(*drpev)) {
 263                dev_err(dev, "Not enough data to decode DRP Notification "
 264                        "for filtering. Expected %zu, received %zu.\n",
 265                        (size_t)sizeof(*drpev), bytes_left);
 266                return -EINVAL;
 267        }
 268        ielength = le16_to_cpu(drpev->wIELength);
 269        bytes_left -= sizeof(*drpev);
 270        if (bytes_left < ielength) {
 271                dev_err(dev, "DRP Notification filter: header length [%zu "
 272                        "bytes] does not match actual length [%zu "
 273                        "bytes].\n", ielength, bytes_left);
 274                return -EINVAL;
 275        }
 276        newdrpev = kzalloc(sizeof(*newdrpev) + ielength, GFP_ATOMIC);
 277        if (newdrpev == NULL)
 278                return -ENOMEM;
 279        newdrpev->rceb = drpev->rceb;
 280        newdrpev->src_addr = drpev->wSrcAddr;
 281        newdrpev->reason = UWB_DRP_NOTIF_DRP_IE_RCVD;
 282        newdrpev->beacon_slot_number = 0;
 283        newdrpev->ie_length = drpev->wIELength;
 284        memcpy(newdrpev->ie_data, drpev->IEData, ielength);
 285        *header = &newdrpev->rceb;
 286        *new_size = sizeof(*newdrpev) + ielength;
 287        return 1; /* calling function will free memory */
 288}
 289
 290
 291/* Scan Command (WUSB 1.0 [8.6.2.5]) */
 292struct uwb_rc_cmd_scan_WUSB_0100 {
 293        struct uwb_rccb rccb;
 294        u8 bChannelNumber;
 295        u8 bScanState;
 296} __attribute__((packed));
 297
 298/**
 299 * Filter WHCI 0.95 SCAN command to be WUSB 1.0 SCAN command
 300 *
 301 * @header:   command sent to device (compliant to WHCI 0.95)
 302 * @size:     size of command sent to device
 303 *
 304 * We only reduce the size by two bytes because the WUSB 1.0 scan command
 305 * does not have the last field (wStarttime). Also, make sure we don't send
 306 * the device an unexpected scan type.
 307 */
 308static
 309int hwarc_filter_cmd_scan_WUSB_0100(struct uwb_rc *rc,
 310                                    struct uwb_rccb **header,
 311                                    size_t *size)
 312{
 313        struct uwb_rc_cmd_scan *sc;
 314
 315        sc = container_of(*header, struct uwb_rc_cmd_scan, rccb);
 316
 317        if (sc->bScanState == UWB_SCAN_ONLY_STARTTIME)
 318                sc->bScanState = UWB_SCAN_ONLY;
 319        /* Don't send the last two bytes. */
 320        *size -= 2;
 321        return 0;
 322}
 323
 324
 325/* SET DRP IE command (WUSB 1.0 [8.6.2.7]) */
 326struct uwb_rc_cmd_set_drp_ie_WUSB_0100 {
 327        struct uwb_rccb rccb;
 328        u8 bExplicit;
 329        __le16 wIELength;
 330        struct uwb_ie_drp IEData[];
 331} __attribute__((packed));
 332
 333/**
 334 * Filter WHCI 0.95 SET DRP IE command to be WUSB 1.0 SET DRP IE command
 335 *
 336 * @header:   command sent to device (compliant to WHCI 0.95)
 337 * @size:     size of command sent to device
 338 *
 339 * WUSB has an extra bExplicit field - we assume always explicit
 340 * negotiation so this field is set. The command expected by the device is
 341 * thus larger than the one prepared by the driver so we need to
 342 * reallocate memory to accommodate this.
 343 * We trust the driver to send us the correct data so no checking is done
 344 * on incoming data - evn though it is variable length.
 345 */
 346static
 347int hwarc_filter_cmd_set_drp_ie_WUSB_0100(struct uwb_rc *rc,
 348                                          struct uwb_rccb **header,
 349                                          size_t *size)
 350{
 351        struct uwb_rc_cmd_set_drp_ie *orgcmd;
 352        struct uwb_rc_cmd_set_drp_ie_WUSB_0100 *cmd;
 353        size_t ielength;
 354
 355        orgcmd = container_of(*header, struct uwb_rc_cmd_set_drp_ie, rccb);
 356        ielength = le16_to_cpu(orgcmd->wIELength);
 357        cmd = kzalloc(sizeof(*cmd) + ielength, GFP_KERNEL);
 358        if (cmd == NULL)
 359                return -ENOMEM;
 360        cmd->rccb = orgcmd->rccb;
 361        cmd->bExplicit = 0;
 362        cmd->wIELength = orgcmd->wIELength;
 363        memcpy(cmd->IEData, orgcmd->IEData, ielength);
 364        *header = &cmd->rccb;
 365        *size = sizeof(*cmd) + ielength;
 366        return 1; /* calling function will free memory */
 367}
 368
 369
 370/**
 371 * Filter data from WHCI driver to WUSB device
 372 *
 373 * @header: WHCI 0.95 compliant command from driver
 374 * @size:   length of command
 375 *
 376 * The routine managing commands to the device (uwb_rc_cmd()) will call the
 377 * filtering function pointer (if it exists) before it passes any data to
 378 * the device. At this time the command has been formatted according to
 379 * WHCI 0.95 and is ready to be sent to the device.
 380 *
 381 * The filter function will be provided with the current command and its
 382 * length. The function will manipulate the command if necessary and
 383 * potentially reallocate memory for a command that needed more memory that
 384 * the given command. If new memory was created the function will return 1
 385 * to indicate to the calling function that the memory need to be freed
 386 * when not needed any more. The size will contain the new length of the
 387 * command.
 388 * If memory has not been allocated we rely on the original mechanisms to
 389 * free the memory of the command - even when we reduce the value of size.
 390 */
 391static
 392int hwarc_filter_cmd_WUSB_0100(struct uwb_rc *rc, struct uwb_rccb **header,
 393                               size_t *size)
 394{
 395        int result;
 396        struct uwb_rccb *rccb = *header;
 397        int cmd = le16_to_cpu(rccb->wCommand);
 398        switch (cmd) {
 399        case UWB_RC_CMD_SCAN:
 400                result = hwarc_filter_cmd_scan_WUSB_0100(rc, header, size);
 401                break;
 402        case UWB_RC_CMD_SET_DRP_IE:
 403                result = hwarc_filter_cmd_set_drp_ie_WUSB_0100(rc, header, size);
 404                break;
 405        default:
 406                result = -ENOANO;
 407                break;
 408        }
 409        return result;
 410}
 411
 412
 413/**
 414 * Filter data from WHCI driver to WUSB device
 415 *
 416 * @header: WHCI 0.95 compliant command from driver
 417 * @size:   length of command
 418 *
 419 * Filter commands based on which protocol the device supports. The WUSB
 420 * errata should be the same as WHCI 0.95 so we do not filter that here -
 421 * only WUSB 1.0.
 422 */
 423static
 424int hwarc_filter_cmd(struct uwb_rc *rc, struct uwb_rccb **header,
 425                     size_t *size)
 426{
 427        int result = -ENOANO;
 428        if (rc->version == 0x0100)
 429                result = hwarc_filter_cmd_WUSB_0100(rc, header, size);
 430        return result;
 431}
 432
 433
 434/**
 435 * Compute return value as sum of incoming value and value at given offset
 436 *
 437 * @rceb:      event for which we compute the size, it contains a variable
 438 *             length field.
 439 * @core_size: size of the "non variable" part of the event
 440 * @offset:    place in event where the length of the variable part is stored
 441 * @buf_size: total length of buffer in which event arrived - we need to make
 442 *             sure we read the offset in memory that is still part of the event
 443 */
 444static
 445ssize_t hwarc_get_event_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
 446                             size_t core_size, size_t offset,
 447                             const size_t buf_size)
 448{
 449        ssize_t size = -ENOSPC;
 450        const void *ptr = rceb;
 451        size_t type_size = sizeof(__le16);
 452        struct device *dev = &rc->uwb_dev.dev;
 453
 454        if (offset + type_size >= buf_size) {
 455                dev_err(dev, "Not enough data to read extra size of event "
 456                        "0x%02x/%04x/%02x, only got %zu bytes.\n",
 457                        rceb->bEventType, le16_to_cpu(rceb->wEvent),
 458                        rceb->bEventContext, buf_size);
 459                goto out;
 460        }
 461        ptr += offset;
 462        size = core_size + le16_to_cpu(*(__le16 *)ptr);
 463out:
 464        return size;
 465}
 466
 467
 468/* Beacon slot change notification (WUSB 1.0 [8.6.3.5]) */
 469struct uwb_rc_evt_bp_slot_change_WUSB_0100 {
 470        struct uwb_rceb rceb;
 471        u8 bSlotNumber;
 472} __attribute__((packed));
 473
 474
 475/**
 476 * Filter data from WUSB device to WHCI driver
 477 *
 478 * @header:      incoming event
 479 * @buf_size:    size of buffer in which event arrived
 480 * @_event_size: actual size of event in the buffer
 481 * @new_size:    size of event after filtered
 482 *
 483 * We don't know how the buffer is constructed - there may be more than one
 484 * event in it so buffer length does not determine event length. We first
 485 * determine the expected size of the incoming event. This value is passed
 486 * back only if the actual filtering succeeded (so we know the computed
 487 * expected size is correct). This value will be zero if
 488 * the event did not need any filtering.
 489 *
 490 * WHCI interprets the BP Slot Change event's data differently than
 491 * WUSB. The event sizes are exactly the same. The data field
 492 * indicates the new beacon slot in which a RC is transmitting its
 493 * beacon. The maximum value of this is 96 (wMacBPLength ECMA-368
 494 * 17.16 (Table 117)). We thus know that the WUSB value will not set
 495 * the bit bNoSlot, so we don't really do anything (placeholder).
 496 */
 497static
 498int hwarc_filter_event_WUSB_0100(struct uwb_rc *rc, struct uwb_rceb **header,
 499                                 const size_t buf_size, size_t *_real_size,
 500                                 size_t *_new_size)
 501{
 502        int result = -ENOANO;
 503        struct uwb_rceb *rceb = *header;
 504        int event = le16_to_cpu(rceb->wEvent);
 505        ssize_t event_size;
 506        size_t core_size, offset;
 507
 508        if (rceb->bEventType != UWB_RC_CET_GENERAL)
 509                goto out;
 510        switch (event) {
 511        case UWB_RC_EVT_BEACON:
 512                core_size = sizeof(struct uwb_rc_evt_beacon_WUSB_0100);
 513                offset = offsetof(struct uwb_rc_evt_beacon_WUSB_0100,
 514                                  wBeaconInfoLength);
 515                event_size = hwarc_get_event_size(rc, rceb, core_size,
 516                                                  offset, buf_size);
 517                if (event_size < 0)
 518                        goto out;
 519                *_real_size = event_size;
 520                result = hwarc_filter_evt_beacon_WUSB_0100(rc, header,
 521                                                           buf_size, _new_size);
 522                break;
 523        case UWB_RC_EVT_BP_SLOT_CHANGE:
 524                *_new_size = *_real_size =
 525                        sizeof(struct uwb_rc_evt_bp_slot_change_WUSB_0100);
 526                result = 0;
 527                break;
 528
 529        case UWB_RC_EVT_DRP_AVAIL:
 530                core_size = sizeof(struct uwb_rc_evt_drp_avail_WUSB_0100);
 531                offset = offsetof(struct uwb_rc_evt_drp_avail_WUSB_0100,
 532                                  wIELength);
 533                event_size = hwarc_get_event_size(rc, rceb, core_size,
 534                                                  offset, buf_size);
 535                if (event_size < 0)
 536                        goto out;
 537                *_real_size = event_size;
 538                result = hwarc_filter_evt_drp_avail_WUSB_0100(
 539                        rc, header, buf_size, _new_size);
 540                break;
 541
 542        case UWB_RC_EVT_DRP:
 543                core_size = sizeof(struct uwb_rc_evt_drp_WUSB_0100);
 544                offset = offsetof(struct uwb_rc_evt_drp_WUSB_0100, wIELength);
 545                event_size = hwarc_get_event_size(rc, rceb, core_size,
 546                                                  offset, buf_size);
 547                if (event_size < 0)
 548                        goto out;
 549                *_real_size = event_size;
 550                result = hwarc_filter_evt_drp_WUSB_0100(rc, header,
 551                                                        buf_size, _new_size);
 552                break;
 553
 554        default:
 555                break;
 556        }
 557out:
 558        return result;
 559}
 560
 561/**
 562 * Filter data from WUSB device to WHCI driver
 563 *
 564 * @header:      incoming event
 565 * @buf_size:    size of buffer in which event arrived
 566 * @_event_size: actual size of event in the buffer
 567 * @_new_size:   size of event after filtered
 568 *
 569 * Filter events based on which protocol the device supports. The WUSB
 570 * errata should be the same as WHCI 0.95 so we do not filter that here -
 571 * only WUSB 1.0.
 572 *
 573 * If we don't handle it, we return -ENOANO (why the weird error code?
 574 * well, so if I get it, I can pinpoint in the code that raised
 575 * it...after all, not too many places use the higher error codes).
 576 */
 577static
 578int hwarc_filter_event(struct uwb_rc *rc, struct uwb_rceb **header,
 579                       const size_t buf_size, size_t *_real_size,
 580                       size_t *_new_size)
 581{
 582        int result = -ENOANO;
 583        if (rc->version == 0x0100)
 584                result =  hwarc_filter_event_WUSB_0100(
 585                        rc, header, buf_size, _real_size, _new_size);
 586        return result;
 587}
 588
 589
 590/**
 591 * Execute an UWB RC command on HWA
 592 *
 593 * @rc:       Instance of a Radio Controller that is a HWA
 594 * @cmd:      Buffer containing the RCCB and payload to execute
 595 * @cmd_size: Size of the command buffer.
 596 *
 597 * NOTE: rc's mutex has to be locked
 598 */
 599static
 600int hwarc_cmd(struct uwb_rc *uwb_rc, const struct uwb_rccb *cmd, size_t cmd_size)
 601{
 602        struct hwarc *hwarc = uwb_rc->priv;
 603        return usb_control_msg(
 604                hwarc->usb_dev, usb_sndctrlpipe(hwarc->usb_dev, 0),
 605                WA_EXEC_RC_CMD, USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 606                0, hwarc->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 607                (void *) cmd, cmd_size, 100 /* FIXME: this is totally arbitrary */);
 608}
 609
 610static
 611int hwarc_reset(struct uwb_rc *uwb_rc)
 612{
 613        struct hwarc *hwarc = uwb_rc->priv;
 614        int result;
 615
 616        /* device lock must be held when calling usb_reset_device. */
 617        result = usb_lock_device_for_reset(hwarc->usb_dev, NULL);
 618        if (result >= 0) {
 619                result = usb_reset_device(hwarc->usb_dev);
 620                usb_unlock_device(hwarc->usb_dev);
 621        }
 622
 623        return result;
 624}
 625
 626/**
 627 * Callback for the notification and event endpoint
 628 *
 629 * Check's that everything is fine and then passes the read data to
 630 * the notification/event handling mechanism (neh).
 631 */
 632static
 633void hwarc_neep_cb(struct urb *urb)
 634{
 635        struct hwarc *hwarc = urb->context;
 636        struct usb_interface *usb_iface = hwarc->usb_iface;
 637        struct device *dev = &usb_iface->dev;
 638        int result;
 639
 640        switch (result = urb->status) {
 641        case 0:
 642                uwb_rc_neh_grok(hwarc->uwb_rc, urb->transfer_buffer,
 643                                urb->actual_length);
 644                break;
 645        case -ECONNRESET:       /* Not an error, but a controlled situation; */
 646        case -ENOENT:           /* (we killed the URB)...so, no broadcast */
 647                goto out;
 648        case -ESHUTDOWN:        /* going away! */
 649                goto out;
 650        default:                /* On general errors, retry unless it gets ugly */
 651                if (edc_inc(&hwarc->neep_edc, EDC_MAX_ERRORS,
 652                            EDC_ERROR_TIMEFRAME))
 653                        goto error_exceeded;
 654                dev_err(dev, "NEEP: URB error %d\n", urb->status);
 655        }
 656        result = usb_submit_urb(urb, GFP_ATOMIC);
 657        if (result < 0 && result != -ENODEV && result != -EPERM) {
 658                /* ignoring unrecoverable errors */
 659                dev_err(dev, "NEEP: Can't resubmit URB (%d) resetting device\n",
 660                        result);
 661                goto error;
 662        }
 663out:
 664        return;
 665
 666error_exceeded:
 667        dev_err(dev, "NEEP: URB max acceptable errors "
 668                "exceeded, resetting device\n");
 669error:
 670        uwb_rc_neh_error(hwarc->uwb_rc, result);
 671        uwb_rc_reset_all(hwarc->uwb_rc);
 672        return;
 673}
 674
 675static void hwarc_init(struct hwarc *hwarc)
 676{
 677        edc_init(&hwarc->neep_edc);
 678}
 679
 680/**
 681 * Initialize the notification/event endpoint stuff
 682 *
 683 * Note this is effectively a parallel thread; it knows that
 684 * hwarc->uwb_rc always exists because the existence of a 'hwarc'
 685 * means that there is a reverence on the hwarc->uwb_rc (see
 686 * _probe()), and thus _neep_cb() can execute safely.
 687 */
 688static int hwarc_neep_init(struct uwb_rc *rc)
 689{
 690        struct hwarc *hwarc = rc->priv;
 691        struct usb_interface *iface = hwarc->usb_iface;
 692        struct usb_device *usb_dev = interface_to_usbdev(iface);
 693        struct device *dev = &iface->dev;
 694        int result;
 695        struct usb_endpoint_descriptor *epd;
 696
 697        epd = &iface->cur_altsetting->endpoint[0].desc;
 698        hwarc->rd_buffer = (void *) __get_free_page(GFP_KERNEL);
 699        if (hwarc->rd_buffer == NULL) {
 700                dev_err(dev, "Unable to allocate notification's read buffer\n");
 701                goto error_rd_buffer;
 702        }
 703        hwarc->neep_urb = usb_alloc_urb(0, GFP_KERNEL);
 704        if (hwarc->neep_urb == NULL) {
 705                dev_err(dev, "Unable to allocate notification URB\n");
 706                goto error_urb_alloc;
 707        }
 708        usb_fill_int_urb(hwarc->neep_urb, usb_dev,
 709                         usb_rcvintpipe(usb_dev, epd->bEndpointAddress),
 710                         hwarc->rd_buffer, PAGE_SIZE,
 711                         hwarc_neep_cb, hwarc, epd->bInterval);
 712        result = usb_submit_urb(hwarc->neep_urb, GFP_ATOMIC);
 713        if (result < 0) {
 714                dev_err(dev, "Cannot submit notification URB: %d\n", result);
 715                goto error_neep_submit;
 716        }
 717        return 0;
 718
 719error_neep_submit:
 720        usb_free_urb(hwarc->neep_urb);
 721        hwarc->neep_urb = NULL;
 722error_urb_alloc:
 723        free_page((unsigned long)hwarc->rd_buffer);
 724        hwarc->rd_buffer = NULL;
 725error_rd_buffer:
 726        return -ENOMEM;
 727}
 728
 729
 730/** Clean up all the notification endpoint resources */
 731static void hwarc_neep_release(struct uwb_rc *rc)
 732{
 733        struct hwarc *hwarc = rc->priv;
 734
 735        usb_kill_urb(hwarc->neep_urb);
 736        usb_free_urb(hwarc->neep_urb);
 737        hwarc->neep_urb = NULL;
 738
 739        free_page((unsigned long)hwarc->rd_buffer);
 740        hwarc->rd_buffer = NULL;
 741}
 742
 743/**
 744 * Get the version from class-specific descriptor
 745 *
 746 * NOTE: this descriptor comes with the big bundled configuration
 747 *       descriptor that includes the interfaces' and endpoints', so
 748 *       we just look for it in the cached copy kept by the USB stack.
 749 *
 750 * NOTE2: We convert LE fields to CPU order.
 751 */
 752static int hwarc_get_version(struct uwb_rc *rc)
 753{
 754        int result;
 755
 756        struct hwarc *hwarc = rc->priv;
 757        struct uwb_rc_control_intf_class_desc *descr;
 758        struct device *dev = &rc->uwb_dev.dev;
 759        struct usb_device *usb_dev = hwarc->usb_dev;
 760        char *itr;
 761        struct usb_descriptor_header *hdr;
 762        size_t itr_size, actconfig_idx;
 763        u16 version;
 764
 765        actconfig_idx = (usb_dev->actconfig - usb_dev->config) /
 766                sizeof(usb_dev->config[0]);
 767        itr = usb_dev->rawdescriptors[actconfig_idx];
 768        itr_size = le16_to_cpu(usb_dev->actconfig->desc.wTotalLength);
 769        while (itr_size >= sizeof(*hdr)) {
 770                hdr = (struct usb_descriptor_header *) itr;
 771                dev_dbg(dev, "Extra device descriptor: "
 772                        "type %02x/%u bytes @ %zu (%zu left)\n",
 773                        hdr->bDescriptorType, hdr->bLength,
 774                        (itr - usb_dev->rawdescriptors[actconfig_idx]),
 775                        itr_size);
 776                if (hdr->bDescriptorType == USB_DT_CS_RADIO_CONTROL)
 777                        goto found;
 778                itr += hdr->bLength;
 779                itr_size -= hdr->bLength;
 780        }
 781        dev_err(dev, "cannot find Radio Control Interface Class descriptor\n");
 782        return -ENODEV;
 783
 784found:
 785        result = -EINVAL;
 786        if (hdr->bLength > itr_size) {  /* is it available? */
 787                dev_err(dev, "incomplete Radio Control Interface Class "
 788                        "descriptor (%zu bytes left, %u needed)\n",
 789                        itr_size, hdr->bLength);
 790                goto error;
 791        }
 792        if (hdr->bLength < sizeof(*descr)) {
 793                dev_err(dev, "short Radio Control Interface Class "
 794                        "descriptor\n");
 795                goto error;
 796        }
 797        descr = (struct uwb_rc_control_intf_class_desc *) hdr;
 798        /* Make LE fields CPU order */
 799        version = __le16_to_cpu(descr->bcdRCIVersion);
 800        if (version != 0x0100) {
 801                dev_err(dev, "Device reports protocol version 0x%04x. We "
 802                        "do not support that. \n", version);
 803                result = -EINVAL;
 804                goto error;
 805        }
 806        rc->version = version;
 807        dev_dbg(dev, "Device supports WUSB protocol version 0x%04x \n", rc->version);
 808        result = 0;
 809error:
 810        return result;
 811}
 812
 813/*
 814 * By creating a 'uwb_rc', we have a reference on it -- that reference
 815 * is the one we drop when we disconnect.
 816 *
 817 * No need to switch altsettings; according to WUSB1.0[8.6.1.1], there
 818 * is only one altsetting allowed.
 819 */
 820static int hwarc_probe(struct usb_interface *iface,
 821                       const struct usb_device_id *id)
 822{
 823        int result;
 824        struct uwb_rc *uwb_rc;
 825        struct hwarc *hwarc;
 826        struct device *dev = &iface->dev;
 827
 828        result = -ENOMEM;
 829        uwb_rc = uwb_rc_alloc();
 830        if (uwb_rc == NULL) {
 831                dev_err(dev, "unable to allocate RC instance\n");
 832                goto error_rc_alloc;
 833        }
 834        hwarc = kzalloc(sizeof(*hwarc), GFP_KERNEL);
 835        if (hwarc == NULL) {
 836                dev_err(dev, "unable to allocate HWA RC instance\n");
 837                goto error_alloc;
 838        }
 839        hwarc_init(hwarc);
 840        hwarc->usb_dev = usb_get_dev(interface_to_usbdev(iface));
 841        hwarc->usb_iface = usb_get_intf(iface);
 842        hwarc->uwb_rc = uwb_rc;
 843
 844        uwb_rc->owner = THIS_MODULE;
 845        uwb_rc->start = hwarc_neep_init;
 846        uwb_rc->stop  = hwarc_neep_release;
 847        uwb_rc->cmd   = hwarc_cmd;
 848        uwb_rc->reset = hwarc_reset;
 849        if (id->driver_info & WUSB_QUIRK_WHCI_CMD_EVT) {
 850                uwb_rc->filter_cmd   = NULL;
 851                uwb_rc->filter_event = NULL;
 852        } else {
 853                uwb_rc->filter_cmd   = hwarc_filter_cmd;
 854                uwb_rc->filter_event = hwarc_filter_event;
 855        }
 856
 857        result = uwb_rc_add(uwb_rc, dev, hwarc);
 858        if (result < 0)
 859                goto error_rc_add;
 860        result = hwarc_get_version(uwb_rc);
 861        if (result < 0) {
 862                dev_err(dev, "cannot retrieve version of RC \n");
 863                goto error_get_version;
 864        }
 865        usb_set_intfdata(iface, hwarc);
 866        return 0;
 867
 868error_get_version:
 869        uwb_rc_rm(uwb_rc);
 870error_rc_add:
 871        usb_put_intf(iface);
 872        usb_put_dev(hwarc->usb_dev);
 873error_alloc:
 874        uwb_rc_put(uwb_rc);
 875error_rc_alloc:
 876        return result;
 877}
 878
 879static void hwarc_disconnect(struct usb_interface *iface)
 880{
 881        struct hwarc *hwarc = usb_get_intfdata(iface);
 882        struct uwb_rc *uwb_rc = hwarc->uwb_rc;
 883
 884        usb_set_intfdata(hwarc->usb_iface, NULL);
 885        uwb_rc_rm(uwb_rc);
 886        usb_put_intf(hwarc->usb_iface);
 887        usb_put_dev(hwarc->usb_dev);
 888        kfree(hwarc);
 889        uwb_rc_put(uwb_rc);     /* when creating the device, refcount = 1 */
 890}
 891
 892static int hwarc_pre_reset(struct usb_interface *iface)
 893{
 894        struct hwarc *hwarc = usb_get_intfdata(iface);
 895        struct uwb_rc *uwb_rc = hwarc->uwb_rc;
 896
 897        uwb_rc_pre_reset(uwb_rc);
 898        return 0;
 899}
 900
 901static int hwarc_post_reset(struct usb_interface *iface)
 902{
 903        struct hwarc *hwarc = usb_get_intfdata(iface);
 904        struct uwb_rc *uwb_rc = hwarc->uwb_rc;
 905
 906        return uwb_rc_post_reset(uwb_rc);
 907}
 908
 909/** USB device ID's that we handle */
 910static const struct usb_device_id hwarc_id_table[] = {
 911        /* D-Link DUB-1210 */
 912        { USB_DEVICE_AND_INTERFACE_INFO(0x07d1, 0x3d02, 0xe0, 0x01, 0x02),
 913          .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
 914        /* Intel i1480 (using firmware 1.3PA2-20070828) */
 915        { USB_DEVICE_AND_INTERFACE_INFO(0x8086, 0x0c3b, 0xe0, 0x01, 0x02),
 916          .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
 917        /* Alereon 5310 */
 918        { USB_DEVICE_AND_INTERFACE_INFO(0x13dc, 0x5310, 0xe0, 0x01, 0x02),
 919          .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
 920        /* Alereon 5611 */
 921        { USB_DEVICE_AND_INTERFACE_INFO(0x13dc, 0x5611, 0xe0, 0x01, 0x02),
 922          .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
 923        /* Generic match for the Radio Control interface */
 924        { USB_INTERFACE_INFO(0xe0, 0x01, 0x02), },
 925        { },
 926};
 927MODULE_DEVICE_TABLE(usb, hwarc_id_table);
 928
 929static struct usb_driver hwarc_driver = {
 930        .name =         "hwa-rc",
 931        .id_table =     hwarc_id_table,
 932        .probe =        hwarc_probe,
 933        .disconnect =   hwarc_disconnect,
 934        .pre_reset =    hwarc_pre_reset,
 935        .post_reset =   hwarc_post_reset,
 936};
 937
 938module_usb_driver(hwarc_driver);
 939
 940MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 941MODULE_DESCRIPTION("Host Wireless Adapter Radio Control Driver");
 942MODULE_LICENSE("GPL");
 943
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