drivers/staging/most/usb/usb.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * usb.c - Hardware dependent module for USB
   4  *
   5  * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9 #include <linux/module.h>
  10 #include <linux/fs.h>
  11 #include <linux/usb.h>
  12 #include <linux/slab.h>
  13 #include <linux/init.h>
  14 #include <linux/cdev.h>
  15 #include <linux/device.h>
  16 #include <linux/list.h>
  17 #include <linux/completion.h>
  18 #include <linux/mutex.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/sysfs.h>
  23 #include <linux/dma-mapping.h>
  24 #include <linux/etherdevice.h>
  25 #include <linux/uaccess.h>
  26
  27 #include "../most.h"
  28
  29 #define USB_MTU                 512
  30 #define NO_ISOCHRONOUS_URB      0
  31 #define AV_PACKETS_PER_XACT     2
  32 #define BUF_CHAIN_SIZE          0xFFFF
  33 #define MAX_NUM_ENDPOINTS       30
  34 #define MAX_SUFFIX_LEN          10
  35 #define MAX_STRING_LEN          80
  36 #define MAX_BUF_SIZE            0xFFFF
  37
  38 #define USB_VENDOR_ID_SMSC      0x0424  /* VID: SMSC */
  39 #define USB_DEV_ID_BRDG         0xC001  /* PID: USB Bridge */
  40 #define USB_DEV_ID_OS81118      0xCF18  /* PID: USB OS81118 */
  41 #define USB_DEV_ID_OS81119      0xCF19  /* PID: USB OS81119 */
  42 #define USB_DEV_ID_OS81210      0xCF30  /* PID: USB OS81210 */
  43 /* DRCI Addresses */
  44 #define DRCI_REG_NI_STATE       0x0100
  45 #define DRCI_REG_PACKET_BW      0x0101
  46 #define DRCI_REG_NODE_ADDR      0x0102
  47 #define DRCI_REG_NODE_POS       0x0103
  48 #define DRCI_REG_MEP_FILTER     0x0140
  49 #define DRCI_REG_HASH_TBL0      0x0141
  50 #define DRCI_REG_HASH_TBL1      0x0142
  51 #define DRCI_REG_HASH_TBL2      0x0143
  52 #define DRCI_REG_HASH_TBL3      0x0144
  53 #define DRCI_REG_HW_ADDR_HI     0x0145
  54 #define DRCI_REG_HW_ADDR_MI     0x0146
  55 #define DRCI_REG_HW_ADDR_LO     0x0147
  56 #define DRCI_REG_BASE           0x1100
  57 #define DRCI_COMMAND            0x02
  58 #define DRCI_READ_REQ           0xA0
  59 #define DRCI_WRITE_REQ          0xA1
  60
  61 /**
  62  * struct most_dci_obj - Direct Communication Interface
  63  * @kobj:position in sysfs
  64  * @usb_device: pointer to the usb device
  65  * @reg_addr: register address for arbitrary DCI access
  66  */
  67 struct most_dci_obj {
  68         struct device dev;
  69         struct usb_device *usb_device;
  70         u16 reg_addr;
  71 };
  72
  73 #define to_dci_obj(p) container_of(p, struct most_dci_obj, dev)
  74
  75 struct most_dev;
  76
  77 struct clear_hold_work {
  78         struct work_struct ws;
  79         struct most_dev *mdev;
  80         unsigned int channel;
  81         int pipe;
  82 };
  83
  84 #define to_clear_hold_work(w) container_of(w, struct clear_hold_work, ws)
  85
  86 /**
  87  * struct most_dev - holds all usb interface specific stuff
  88  * @usb_device: pointer to usb device
  89  * @iface: hardware interface
  90  * @cap: channel capabilities
  91  * @conf: channel configuration
  92  * @dci: direct communication interface of hardware
  93  * @ep_address: endpoint address table
  94  * @description: device description
  95  * @suffix: suffix for channel name
  96  * @channel_lock: synchronize channel access
  97  * @padding_active: indicates channel uses padding
  98  * @is_channel_healthy: health status table of each channel
  99  * @busy_urbs: list of anchored items
 100  * @io_mutex: synchronize I/O with disconnect
 101  * @link_stat_timer: timer for link status reports
 102  * @poll_work_obj: work for polling link status
 103  */
 104 struct most_dev {
 105         struct usb_device *usb_device;
 106         struct most_interface iface;
 107         struct most_channel_capability *cap;
 108         struct most_channel_config *conf;
 109         struct most_dci_obj *dci;
 110         u8 *ep_address;
 111         char description[MAX_STRING_LEN];
 112         char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
 113         spinlock_t channel_lock[MAX_NUM_ENDPOINTS]; /* sync channel access */
 114         bool padding_active[MAX_NUM_ENDPOINTS];
 115         bool is_channel_healthy[MAX_NUM_ENDPOINTS];
 116         struct clear_hold_work clear_work[MAX_NUM_ENDPOINTS];
 117         struct usb_anchor *busy_urbs;
 118         struct mutex io_mutex;
 119         struct timer_list link_stat_timer;
 120         struct work_struct poll_work_obj;
 121         void (*on_netinfo)(struct most_interface *most_iface,
 122                            unsigned char link_state, unsigned char *addrs);
 123 };
 124
 125 #define to_mdev(d) container_of(d, struct most_dev, iface)
 126 #define to_mdev_from_work(w) container_of(w, struct most_dev, poll_work_obj)
 127
 128 static void wq_clear_halt(struct work_struct *wq_obj);
 129 static void wq_netinfo(struct work_struct *wq_obj);
 130
 131 /**
 132  * drci_rd_reg - read a DCI register
 133  * @dev: usb device
 134  * @reg: register address
 135  * @buf: buffer to store data
 136  *
 137  * This is reads data from INIC's direct register communication interface
 138  */
 139 static inline int drci_rd_reg(struct usb_device *dev, u16 reg, u16 *buf)
 140 {
 141         int retval;
 142         __le16 *dma_buf = kzalloc(sizeof(*dma_buf), GFP_KERNEL);
 143         u8 req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
 144
 145         if (!dma_buf)
 146                 return -ENOMEM;
 147
 148         retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 149                                  DRCI_READ_REQ, req_type,
 150                                  0x0000,
 151                                  reg, dma_buf, sizeof(*dma_buf), 5 * HZ);
 152         *buf = le16_to_cpu(*dma_buf);
 153         kfree(dma_buf);
 154
 155         return retval;
 156 }
 157
 158 /**
 159  * drci_wr_reg - write a DCI register
 160  * @dev: usb device
 161  * @reg: register address
 162  * @data: data to write
 163  *
 164  * This is writes data to INIC's direct register communication interface
 165  */
 166 static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
 167 {
 168         return usb_control_msg(dev,
 169                                usb_sndctrlpipe(dev, 0),
 170                                DRCI_WRITE_REQ,
 171                                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 172                                data,
 173                                reg,
 174                                NULL,
 175                                0,
 176                                5 * HZ);
 177 }
 178
 179 static inline int start_sync_ep(struct usb_device *usb_dev, u16 ep)
 180 {
 181         return drci_wr_reg(usb_dev, DRCI_REG_BASE + DRCI_COMMAND + ep * 16, 1);
 182 }
 183
 184 /**
 185  * get_stream_frame_size - calculate frame size of current configuration
 186  * @cfg: channel configuration
 187  */
 188 static unsigned int get_stream_frame_size(struct most_channel_config *cfg)
 189 {
 190         unsigned int frame_size = 0;
 191         unsigned int sub_size = cfg->subbuffer_size;
 192
 193         if (!sub_size) {
 194                 pr_warn("Misconfig: Subbuffer size zero.\n");
 195                 return frame_size;
 196         }
 197         switch (cfg->data_type) {
 198         case MOST_CH_ISOC:
 199                 frame_size = AV_PACKETS_PER_XACT * sub_size;
 200                 break;
 201         case MOST_CH_SYNC:
 202                 if (cfg->packets_per_xact == 0) {
 203                         pr_warn("Misconfig: Packets per XACT zero\n");
 204                         frame_size = 0;
 205                 } else if (cfg->packets_per_xact == 0xFF) {
 206                         frame_size = (USB_MTU / sub_size) * sub_size;
 207                 } else {
 208                         frame_size = cfg->packets_per_xact * sub_size;
 209                 }
 210                 break;
 211         default:
 212                 pr_warn("Query frame size of non-streaming channel\n");
 213                 break;
 214         }
 215         return frame_size;
 216 }
 217
 218 /**
 219  * hdm_poison_channel - mark buffers of this channel as invalid
 220  * @iface: pointer to the interface
 221  * @channel: channel ID
 222  *
 223  * This unlinks all URBs submitted to the HCD,
 224  * calls the associated completion function of the core and removes
 225  * them from the list.
 226  *
 227  * Returns 0 on success or error code otherwise.
 228  */
 229 static int hdm_poison_channel(struct most_interface *iface, int channel)
 230 {
 231         struct most_dev *mdev = to_mdev(iface);
 232         unsigned long flags;
 233         spinlock_t *lock; /* temp. lock */
 234
 235         if (unlikely(!iface)) {
 236                 dev_warn(&mdev->usb_device->dev, "Poison: Bad interface.\n");
 237                 return -EIO;
 238         }
 239         if (unlikely(channel < 0 || channel >= iface->num_channels)) {
 240                 dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
 241                 return -ECHRNG;
 242         }
 243
 244         lock = mdev->channel_lock + channel;
 245         spin_lock_irqsave(lock, flags);
 246         mdev->is_channel_healthy[channel] = false;
 247         spin_unlock_irqrestore(lock, flags);
 248
 249         cancel_work_sync(&mdev->clear_work[channel].ws);
 250
 251         mutex_lock(&mdev->io_mutex);
 252         usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
 253         if (mdev->padding_active[channel])
 254                 mdev->padding_active[channel] = false;
 255
 256         if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
 257                 del_timer_sync(&mdev->link_stat_timer);
 258                 cancel_work_sync(&mdev->poll_work_obj);
 259         }
 260         mutex_unlock(&mdev->io_mutex);
 261         return 0;
 262 }
 263
 264 /**
 265  * hdm_add_padding - add padding bytes
 266  * @mdev: most device
 267  * @channel: channel ID
 268  * @mbo: buffer object
 269  *
 270  * This inserts the INIC hardware specific padding bytes into a streaming
 271  * channel's buffer
 272  */
 273 static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
 274 {
 275         struct most_channel_config *conf = &mdev->conf[channel];
 276         unsigned int frame_size = get_stream_frame_size(conf);
 277         unsigned int j, num_frames;
 278
 279         if (!frame_size)
 280                 return -EIO;
 281         num_frames = mbo->buffer_length / frame_size;
 282
 283         if (num_frames < 1) {
 284                 dev_err(&mdev->usb_device->dev,
 285                         "Missed minimal transfer unit.\n");
 286                 return -EIO;
 287         }
 288
 289         for (j = num_frames - 1; j > 0; j--)
 290                 memmove(mbo->virt_address + j * USB_MTU,
 291                         mbo->virt_address + j * frame_size,
 292                         frame_size);
 293         mbo->buffer_length = num_frames * USB_MTU;
 294         return 0;
 295 }
 296
 297 /**
 298  * hdm_remove_padding - remove padding bytes
 299  * @mdev: most device
 300  * @channel: channel ID
 301  * @mbo: buffer object
 302  *
 303  * This takes the INIC hardware specific padding bytes off a streaming
 304  * channel's buffer.
 305  */
 306 static int hdm_remove_padding(struct most_dev *mdev, int channel,
 307                               struct mbo *mbo)
 308 {
 309         struct most_channel_config *const conf = &mdev->conf[channel];
 310         unsigned int frame_size = get_stream_frame_size(conf);
 311         unsigned int j, num_frames;
 312
 313         if (!frame_size)
 314                 return -EIO;
 315         num_frames = mbo->processed_length / USB_MTU;
 316
 317         for (j = 1; j < num_frames; j++)
 318                 memmove(mbo->virt_address + frame_size * j,
 319                         mbo->virt_address + USB_MTU * j,
 320                         frame_size);
 321
 322         mbo->processed_length = frame_size * num_frames;
 323         return 0;
 324 }
 325
 326 /**
 327  * hdm_write_completion - completion function for submitted Tx URBs
 328  * @urb: the URB that has been completed
 329  *
 330  * This checks the status of the completed URB. In case the URB has been
 331  * unlinked before, it is immediately freed. On any other error the MBO
 332  * transfer flag is set. On success it frees allocated resources and calls
 333  * the completion function.
 334  *
 335  * Context: interrupt!
 336  */
 337 static void hdm_write_completion(struct urb *urb)
 338 {
 339         struct mbo *mbo = urb->context;
 340         struct most_dev *mdev = to_mdev(mbo->ifp);
 341         unsigned int channel = mbo->hdm_channel_id;
 342         spinlock_t *lock = mdev->channel_lock + channel;
 343         unsigned long flags;
 344
 345         spin_lock_irqsave(lock, flags);
 346
 347         mbo->processed_length = 0;
 348         mbo->status = MBO_E_INVAL;
 349         if (likely(mdev->is_channel_healthy[channel])) {
 350                 switch (urb->status) {
 351                 case 0:
 352                 case -ESHUTDOWN:
 353                         mbo->processed_length = urb->actual_length;
 354                         mbo->status = MBO_SUCCESS;
 355                         break;
 356                 case -EPIPE:
 357                         dev_warn(&mdev->usb_device->dev,
 358                                  "Broken pipe on ep%02x\n",
 359                                  mdev->ep_address[channel]);
 360                         mdev->is_channel_healthy[channel] = false;
 361                         mdev->clear_work[channel].pipe = urb->pipe;
 362                         schedule_work(&mdev->clear_work[channel].ws);
 363                         break;
 364                 case -ENODEV:
 365                 case -EPROTO:
 366                         mbo->status = MBO_E_CLOSE;
 367                         break;
 368                 }
 369         }
 370
 371         spin_unlock_irqrestore(lock, flags);
 372
 373         if (likely(mbo->complete))
 374                 mbo->complete(mbo);
 375         usb_free_urb(urb);
 376 }
 377
 378 /**
 379  * hdm_read_completion - completion function for submitted Rx URBs
 380  * @urb: the URB that has been completed
 381  *
 382  * This checks the status of the completed URB. In case the URB has been
 383  * unlinked before it is immediately freed. On any other error the MBO transfer
 384  * flag is set. On success it frees allocated resources, removes
 385  * padding bytes -if necessary- and calls the completion function.
 386  *
 387  * Context: interrupt!
 388  *
 389  * **************************************************************************
 390  *                   Error codes returned by in urb->status
 391  *                   or in iso_frame_desc[n].status (for ISO)
 392  * *************************************************************************
 393  *
 394  * USB device drivers may only test urb status values in completion handlers.
 395  * This is because otherwise there would be a race between HCDs updating
 396  * these values on one CPU, and device drivers testing them on another CPU.
 397  *
 398  * A transfer's actual_length may be positive even when an error has been
 399  * reported.  That's because transfers often involve several packets, so that
 400  * one or more packets could finish before an error stops further endpoint I/O.
 401  *
 402  * For isochronous URBs, the urb status value is non-zero only if the URB is
 403  * unlinked, the device is removed, the host controller is disabled or the total
 404  * transferred length is less than the requested length and the URB_SHORT_NOT_OK
 405  * flag is set.  Completion handlers for isochronous URBs should only see
 406  * urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
 407  * Individual frame descriptor status fields may report more status codes.
 408  *
 409  *
 410  * 0                    Transfer completed successfully
 411  *
 412  * -ENOENT              URB was synchronously unlinked by usb_unlink_urb
 413  *
 414  * -EINPROGRESS         URB still pending, no results yet
 415  *                      (That is, if drivers see this it's a bug.)
 416  *
 417  * -EPROTO (*, **)      a) bitstuff error
 418  *                      b) no response packet received within the
 419  *                         prescribed bus turn-around time
 420  *                      c) unknown USB error
 421  *
 422  * -EILSEQ (*, **)      a) CRC mismatch
 423  *                      b) no response packet received within the
 424  *                         prescribed bus turn-around time
 425  *                      c) unknown USB error
 426  *
 427  *                      Note that often the controller hardware does not
 428  *                      distinguish among cases a), b), and c), so a
 429  *                      driver cannot tell whether there was a protocol
 430  *                      error, a failure to respond (often caused by
 431  *                      device disconnect), or some other fault.
 432  *
 433  * -ETIME (**)          No response packet received within the prescribed
 434  *                      bus turn-around time.  This error may instead be
 435  *                      reported as -EPROTO or -EILSEQ.
 436  *
 437  * -ETIMEDOUT           Synchronous USB message functions use this code
 438  *                      to indicate timeout expired before the transfer
 439  *                      completed, and no other error was reported by HC.
 440  *
 441  * -EPIPE (**)          Endpoint stalled.  For non-control endpoints,
 442  *                      reset this status with usb_clear_halt().
 443  *
 444  * -ECOMM               During an IN transfer, the host controller
 445  *                      received data from an endpoint faster than it
 446  *                      could be written to system memory
 447  *
 448  * -ENOSR               During an OUT transfer, the host controller
 449  *                      could not retrieve data from system memory fast
 450  *                      enough to keep up with the USB data rate
 451  *
 452  * -EOVERFLOW (*)       The amount of data returned by the endpoint was
 453  *                      greater than either the max packet size of the
 454  *                      endpoint or the remaining buffer size.  "Babble".
 455  *
 456  * -EREMOTEIO           The data read from the endpoint did not fill the
 457  *                      specified buffer, and URB_SHORT_NOT_OK was set in
 458  *                      urb->transfer_flags.
 459  *
 460  * -ENODEV              Device was removed.  Often preceded by a burst of
 461  *                      other errors, since the hub driver doesn't detect
 462  *                      device removal events immediately.
 463  *
 464  * -EXDEV               ISO transfer only partially completed
 465  *                      (only set in iso_frame_desc[n].status, not urb->status)
 466  *
 467  * -EINVAL              ISO madness, if this happens: Log off and go home
 468  *
 469  * -ECONNRESET          URB was asynchronously unlinked by usb_unlink_urb
 470  *
 471  * -ESHUTDOWN           The device or host controller has been disabled due
 472  *                      to some problem that could not be worked around,
 473  *                      such as a physical disconnect.
 474  *
 475  *
 476  * (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
 477  * hardware problems such as bad devices (including firmware) or cables.
 478  *
 479  * (**) This is also one of several codes that different kinds of host
 480  * controller use to indicate a transfer has failed because of device
 481  * disconnect.  In the interval before the hub driver starts disconnect
 482  * processing, devices may receive such fault reports for every request.
 483  *
 484  * See <https://www.kernel.org/doc/Documentation/driver-api/usb/error-codes.rst>
 485  */
 486 static void hdm_read_completion(struct urb *urb)
 487 {
 488         struct mbo *mbo = urb->context;
 489         struct most_dev *mdev = to_mdev(mbo->ifp);
 490         unsigned int channel = mbo->hdm_channel_id;
 491         struct device *dev = &mdev->usb_device->dev;
 492         spinlock_t *lock = mdev->channel_lock + channel;
 493         unsigned long flags;
 494
 495         spin_lock_irqsave(lock, flags);
 496
 497         mbo->processed_length = 0;
 498         mbo->status = MBO_E_INVAL;
 499         if (likely(mdev->is_channel_healthy[channel])) {
 500                 switch (urb->status) {
 501                 case 0:
 502                 case -ESHUTDOWN:
 503                         mbo->processed_length = urb->actual_length;
 504                         mbo->status = MBO_SUCCESS;
 505                         if (mdev->padding_active[channel] &&
 506                             hdm_remove_padding(mdev, channel, mbo)) {
 507                                 mbo->processed_length = 0;
 508                                 mbo->status = MBO_E_INVAL;
 509                         }
 510                         break;
 511                 case -EPIPE:
 512                         dev_warn(dev, "Broken pipe on ep%02x\n",
 513                                  mdev->ep_address[channel]);
 514                         mdev->is_channel_healthy[channel] = false;
 515                         mdev->clear_work[channel].pipe = urb->pipe;
 516                         schedule_work(&mdev->clear_work[channel].ws);
 517                         break;
 518                 case -ENODEV:
 519                 case -EPROTO:
 520                         mbo->status = MBO_E_CLOSE;
 521                         break;
 522                 case -EOVERFLOW:
 523                         dev_warn(dev, "Babble on ep%02x\n",
 524                                  mdev->ep_address[channel]);
 525                         break;
 526                 }
 527         }
 528
 529         spin_unlock_irqrestore(lock, flags);
 530
 531         if (likely(mbo->complete))
 532                 mbo->complete(mbo);
 533         usb_free_urb(urb);
 534 }
 535
 536 /**
 537  * hdm_enqueue - receive a buffer to be used for data transfer
 538  * @iface: interface to enqueue to
 539  * @channel: ID of the channel
 540  * @mbo: pointer to the buffer object
 541  *
 542  * This allocates a new URB and fills it according to the channel
 543  * that is being used for transmission of data. Before the URB is
 544  * submitted it is stored in the private anchor list.
 545  *
 546  * Returns 0 on success. On any error the URB is freed and a error code
 547  * is returned.
 548  *
 549  * Context: Could in _some_ cases be interrupt!
 550  */
 551 static int hdm_enqueue(struct most_interface *iface, int channel,
 552                        struct mbo *mbo)
 553 {
 554         struct most_dev *mdev;
 555         struct most_channel_config *conf;
 556         int retval = 0;
 557         struct urb *urb;
 558         unsigned long length;
 559         void *virt_address;
 560
 561         if (unlikely(!iface || !mbo))
 562                 return -EIO;
 563         if (unlikely(iface->num_channels <= channel || channel < 0))
 564                 return -ECHRNG;
 565
 566         mdev = to_mdev(iface);
 567         conf = &mdev->conf[channel];
 568
 569         mutex_lock(&mdev->io_mutex);
 570         if (!mdev->usb_device) {
 571                 retval = -ENODEV;
 572                 goto unlock_io_mutex;
 573         }
 574
 575         urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_ATOMIC);
 576         if (!urb) {
 577                 retval = -ENOMEM;
 578                 goto unlock_io_mutex;
 579         }
 580
 581         if ((conf->direction & MOST_CH_TX) && mdev->padding_active[channel] &&
 582             hdm_add_padding(mdev, channel, mbo)) {
 583                 retval = -EIO;
 584                 goto err_free_urb;
 585         }
 586
 587         urb->transfer_dma = mbo->bus_address;
 588         virt_address = mbo->virt_address;
 589         length = mbo->buffer_length;
 590
 591         if (conf->direction & MOST_CH_TX) {
 592                 usb_fill_bulk_urb(urb, mdev->usb_device,
 593                                   usb_sndbulkpipe(mdev->usb_device,
 594                                                   mdev->ep_address[channel]),
 595                                   virt_address,
 596                                   length,
 597                                   hdm_write_completion,
 598                                   mbo);
 599                 if (conf->data_type != MOST_CH_ISOC &&
 600                     conf->data_type != MOST_CH_SYNC)
 601                         urb->transfer_flags |= URB_ZERO_PACKET;
 602         } else {
 603                 usb_fill_bulk_urb(urb, mdev->usb_device,
 604                                   usb_rcvbulkpipe(mdev->usb_device,
 605                                                   mdev->ep_address[channel]),
 606                                   virt_address,
 607                                   length + conf->extra_len,
 608                                   hdm_read_completion,
 609                                   mbo);
 610         }
 611         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 612
 613         usb_anchor_urb(urb, &mdev->busy_urbs[channel]);
 614
 615         retval = usb_submit_urb(urb, GFP_KERNEL);
 616         if (retval) {
 617                 dev_err(&mdev->usb_device->dev,
 618                         "URB submit failed with error %d.\n", retval);
 619                 goto err_unanchor_urb;
 620         }
 621         goto unlock_io_mutex;
 622
 623 err_unanchor_urb:
 624         usb_unanchor_urb(urb);
 625 err_free_urb:
 626         usb_free_urb(urb);
 627 unlock_io_mutex:
 628         mutex_unlock(&mdev->io_mutex);
 629         return retval;
 630 }
 631
 632 static void *hdm_dma_alloc(struct mbo *mbo, u32 size)
 633 {
 634         struct most_dev *mdev = to_mdev(mbo->ifp);
 635
 636         return usb_alloc_coherent(mdev->usb_device, size, GFP_KERNEL,
 637                                   &mbo->bus_address);
 638 }
 639
 640 static void hdm_dma_free(struct mbo *mbo, u32 size)
 641 {
 642         struct most_dev *mdev = to_mdev(mbo->ifp);
 643
 644         usb_free_coherent(mdev->usb_device, size, mbo->virt_address,
 645                           mbo->bus_address);
 646 }
 647
 648 /**
 649  * hdm_configure_channel - receive channel configuration from core
 650  * @iface: interface
 651  * @channel: channel ID
 652  * @conf: structure that holds the configuration information
 653  *
 654  * The attached network interface controller (NIC) supports a padding mode
 655  * to avoid short packets on USB, hence increasing the performance due to a
 656  * lower interrupt load. This mode is default for synchronous data and can
 657  * be switched on for isochronous data. In case padding is active the
 658  * driver needs to know the frame size of the payload in order to calculate
 659  * the number of bytes it needs to pad when transmitting or to cut off when
 660  * receiving data.
 661  *
 662  */
 663 static int hdm_configure_channel(struct most_interface *iface, int channel,
 664                                  struct most_channel_config *conf)
 665 {
 666         unsigned int num_frames;
 667         unsigned int frame_size;
 668         struct most_dev *mdev = to_mdev(iface);
 669         struct device *dev = &mdev->usb_device->dev;
 670
 671         mdev->is_channel_healthy[channel] = true;
 672         mdev->clear_work[channel].channel = channel;
 673         mdev->clear_work[channel].mdev = mdev;
 674         INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
 675
 676         if (unlikely(!iface || !conf)) {
 677                 dev_err(dev, "Bad interface or config pointer.\n");
 678                 return -EINVAL;
 679         }
 680         if (unlikely(channel < 0 || channel >= iface->num_channels)) {
 681                 dev_err(dev, "Channel ID out of range.\n");
 682                 return -EINVAL;
 683         }
 684         if (!conf->num_buffers || !conf->buffer_size) {
 685                 dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
 686                 return -EINVAL;
 687         }
 688
 689         if (conf->data_type != MOST_CH_SYNC &&
 690             !(conf->data_type == MOST_CH_ISOC &&
 691               conf->packets_per_xact != 0xFF)) {
 692                 mdev->padding_active[channel] = false;
 693                 /*
 694                  * Since the NIC's padding mode is not going to be
 695                  * used, we can skip the frame size calculations and
 696                  * move directly on to exit.
 697                  */
 698                 goto exit;
 699         }
 700
 701         mdev->padding_active[channel] = true;
 702
 703         frame_size = get_stream_frame_size(conf);
 704         if (frame_size == 0 || frame_size > USB_MTU) {
 705                 dev_warn(dev, "Misconfig: frame size wrong\n");
 706                 return -EINVAL;
 707         }
 708
 709         num_frames = conf->buffer_size / frame_size;
 710
 711         if (conf->buffer_size % frame_size) {
 712                 u16 old_size = conf->buffer_size;
 713
 714                 conf->buffer_size = num_frames * frame_size;
 715                 dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
 716                          mdev->suffix[channel], old_size, conf->buffer_size);
 717         }
 718
 719         /* calculate extra length to comply w/ HW padding */
 720         conf->extra_len = num_frames * (USB_MTU - frame_size);
 721
 722 exit:
 723         mdev->conf[channel] = *conf;
 724         if (conf->data_type == MOST_CH_ASYNC) {
 725                 u16 ep = mdev->ep_address[channel];
 726
 727                 if (start_sync_ep(mdev->usb_device, ep) < 0)
 728                         dev_warn(dev, "sync for ep%02x failed", ep);
 729         }
 730         return 0;
 731 }
 732
 733 /**
 734  * hdm_request_netinfo - request network information
 735  * @iface: pointer to interface
 736  * @channel: channel ID
 737  *
 738  * This is used as trigger to set up the link status timer that
 739  * polls for the NI state of the INIC every 2 seconds.
 740  *
 741  */
 742 static void hdm_request_netinfo(struct most_interface *iface, int channel,
 743                                 void (*on_netinfo)(struct most_interface *,
 744                                                    unsigned char,
 745                                                    unsigned char *))
 746 {
 747         struct most_dev *mdev;
 748
 749         BUG_ON(!iface);
 750         mdev = to_mdev(iface);
 751         mdev->on_netinfo = on_netinfo;
 752         if (!on_netinfo)
 753                 return;
 754
 755         mdev->link_stat_timer.expires = jiffies + HZ;
 756         mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
 757 }
 758
 759 /**
 760  * link_stat_timer_handler - schedule work obtaining mac address and link status
 761  * @data: pointer to USB device instance
 762  *
 763  * The handler runs in interrupt context. That's why we need to defer the
 764  * tasks to a work queue.
 765  */
 766 static void link_stat_timer_handler(struct timer_list *t)
 767 {
 768         struct most_dev *mdev = from_timer(mdev, t, link_stat_timer);
 769
 770         schedule_work(&mdev->poll_work_obj);
 771         mdev->link_stat_timer.expires = jiffies + (2 * HZ);
 772         add_timer(&mdev->link_stat_timer);
 773 }
 774
 775 /**
 776  * wq_netinfo - work queue function to deliver latest networking information
 777  * @wq_obj: object that holds data for our deferred work to do
 778  *
 779  * This retrieves the network interface status of the USB INIC
 780  */
 781 static void wq_netinfo(struct work_struct *wq_obj)
 782 {
 783         struct most_dev *mdev = to_mdev_from_work(wq_obj);
 784         struct usb_device *usb_device = mdev->usb_device;
 785         struct device *dev = &usb_device->dev;
 786         u16 hi, mi, lo, link;
 787         u8 hw_addr[6];
 788
 789         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi) < 0) {
 790                 dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
 791                 return;
 792         }
 793
 794         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi) < 0) {
 795                 dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
 796                 return;
 797         }
 798
 799         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo) < 0) {
 800                 dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
 801                 return;
 802         }
 803
 804         if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link) < 0) {
 805                 dev_err(dev, "Vendor request 'link status' failed\n");
 806                 return;
 807         }
 808
 809         hw_addr[0] = hi >> 8;
 810         hw_addr[1] = hi;
 811         hw_addr[2] = mi >> 8;
 812         hw_addr[3] = mi;
 813         hw_addr[4] = lo >> 8;
 814         hw_addr[5] = lo;
 815
 816         if (mdev->on_netinfo)
 817                 mdev->on_netinfo(&mdev->iface, link, hw_addr);
 818 }
 819
 820 /**
 821  * wq_clear_halt - work queue function
 822  * @wq_obj: work_struct object to execute
 823  *
 824  * This sends a clear_halt to the given USB pipe.
 825  */
 826 static void wq_clear_halt(struct work_struct *wq_obj)
 827 {
 828         struct clear_hold_work *clear_work = to_clear_hold_work(wq_obj);
 829         struct most_dev *mdev = clear_work->mdev;
 830         unsigned int channel = clear_work->channel;
 831         int pipe = clear_work->pipe;
 832
 833         mutex_lock(&mdev->io_mutex);
 834         most_stop_enqueue(&mdev->iface, channel);
 835         usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
 836         if (usb_clear_halt(mdev->usb_device, pipe))
 837                 dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");
 838
 839         /* If the functional Stall condition has been set on an
 840          * asynchronous rx channel, we need to clear the tx channel
 841          * too, since the hardware runs its clean-up sequence on both
 842          * channels, as they are physically one on the network.
 843          *
 844          * The USB interface that exposes the asynchronous channels
 845          * contains always two endpoints, and two only.
 846          */
 847         if (mdev->conf[channel].data_type == MOST_CH_ASYNC &&
 848             mdev->conf[channel].direction == MOST_CH_RX) {
 849                 int peer = 1 - channel;
 850                 int snd_pipe = usb_sndbulkpipe(mdev->usb_device,
 851                                                mdev->ep_address[peer]);
 852                 usb_clear_halt(mdev->usb_device, snd_pipe);
 853         }
 854         mdev->is_channel_healthy[channel] = true;
 855         most_resume_enqueue(&mdev->iface, channel);
 856         mutex_unlock(&mdev->io_mutex);
 857 }
 858
 859 /**
 860  * hdm_usb_fops - file operation table for USB driver
 861  */
 862 static const struct file_operations hdm_usb_fops = {
 863         .owner = THIS_MODULE,
 864 };
 865
 866 /**
 867  * usb_device_id - ID table for HCD device probing
 868  */
 869 static const struct usb_device_id usbid[] = {
 870         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
 871         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81118), },
 872         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81119), },
 873         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81210), },
 874         { } /* Terminating entry */
 875 };
 876
 877 struct regs {
 878         const char *name;
 879         u16 reg;
 880 };
 881
 882 static const struct regs ro_regs[] = {
 883         { "ni_state", DRCI_REG_NI_STATE },
 884         { "packet_bandwidth", DRCI_REG_PACKET_BW },
 885         { "node_address", DRCI_REG_NODE_ADDR },
 886         { "node_position", DRCI_REG_NODE_POS },
 887 };
 888
 889 static const struct regs rw_regs[] = {
 890         { "mep_filter", DRCI_REG_MEP_FILTER },
 891         { "mep_hash0", DRCI_REG_HASH_TBL0 },
 892         { "mep_hash1", DRCI_REG_HASH_TBL1 },
 893         { "mep_hash2", DRCI_REG_HASH_TBL2 },
 894         { "mep_hash3", DRCI_REG_HASH_TBL3 },
 895         { "mep_eui48_hi", DRCI_REG_HW_ADDR_HI },
 896         { "mep_eui48_mi", DRCI_REG_HW_ADDR_MI },
 897         { "mep_eui48_lo", DRCI_REG_HW_ADDR_LO },
 898 };
 899
 900 static int get_stat_reg_addr(const struct regs *regs, int size,
 901                              const char *name, u16 *reg_addr)
 902 {
 903         int i;
 904
 905         for (i = 0; i < size; i++) {
 906                 if (!strcmp(name, regs[i].name)) {
 907                         *reg_addr = regs[i].reg;
 908                         return 0;
 909                 }
 910         }
 911         return -EFAULT;
 912 }
 913
 914 #define get_static_reg_addr(regs, name, reg_addr) \
 915         get_stat_reg_addr(regs, ARRAY_SIZE(regs), name, reg_addr)
 916
 917 static ssize_t value_show(struct device *dev, struct device_attribute *attr,
 918                           char *buf)
 919 {
 920         const char *name = attr->attr.name;
 921         struct most_dci_obj *dci_obj = to_dci_obj(dev);
 922         u16 val;
 923         u16 reg_addr;
 924         int err;
 925
 926         if (!strcmp(name, "arb_address"))
 927                 return snprintf(buf, PAGE_SIZE, "%04x\n", dci_obj->reg_addr);
 928
 929         if (!strcmp(name, "arb_value"))
 930                 reg_addr = dci_obj->reg_addr;
 931         else if (get_static_reg_addr(ro_regs, name, &reg_addr) &&
 932                  get_static_reg_addr(rw_regs, name, &reg_addr))
 933                 return -EFAULT;
 934
 935         err = drci_rd_reg(dci_obj->usb_device, reg_addr, &val);
 936         if (err < 0)
 937                 return err;
 938
 939         return snprintf(buf, PAGE_SIZE, "%04x\n", val);
 940 }
 941
 942 static ssize_t value_store(struct device *dev, struct device_attribute *attr,
 943                            const char *buf, size_t count)
 944 {
 945         u16 val;
 946         u16 reg_addr;
 947         const char *name = attr->attr.name;
 948         struct most_dci_obj *dci_obj = to_dci_obj(dev);
 949         struct usb_device *usb_dev = dci_obj->usb_device;
 950         int err = kstrtou16(buf, 16, &val);
 951
 952         if (err)
 953                 return err;
 954
 955         if (!strcmp(name, "arb_address")) {
 956                 dci_obj->reg_addr = val;
 957                 return count;
 958         }
 959
 960         if (!strcmp(name, "arb_value"))
 961                 err = drci_wr_reg(usb_dev, dci_obj->reg_addr, val);
 962         else if (!strcmp(name, "sync_ep"))
 963                 err = start_sync_ep(usb_dev, val);
 964         else if (!get_static_reg_addr(rw_regs, name, &reg_addr))
 965                 err = drci_wr_reg(usb_dev, reg_addr, val);
 966         else
 967                 return -EFAULT;
 968
 969         if (err < 0)
 970                 return err;
 971
 972         return count;
 973 }
 974
 975 static DEVICE_ATTR(ni_state, 0444, value_show, NULL);
 976 static DEVICE_ATTR(packet_bandwidth, 0444, value_show, NULL);
 977 static DEVICE_ATTR(node_address, 0444, value_show, NULL);
 978 static DEVICE_ATTR(node_position, 0444, value_show, NULL);
 979 static DEVICE_ATTR(sync_ep, 0200, NULL, value_store);
 980 static DEVICE_ATTR(mep_filter, 0644, value_show, value_store);
 981 static DEVICE_ATTR(mep_hash0, 0644, value_show, value_store);
 982 static DEVICE_ATTR(mep_hash1, 0644, value_show, value_store);
 983 static DEVICE_ATTR(mep_hash2, 0644, value_show, value_store);
 984 static DEVICE_ATTR(mep_hash3, 0644, value_show, value_store);
 985 static DEVICE_ATTR(mep_eui48_hi, 0644, value_show, value_store);
 986 static DEVICE_ATTR(mep_eui48_mi, 0644, value_show, value_store);
 987 static DEVICE_ATTR(mep_eui48_lo, 0644, value_show, value_store);
 988 static DEVICE_ATTR(arb_address, 0644, value_show, value_store);
 989 static DEVICE_ATTR(arb_value, 0644, value_show, value_store);
 990
 991 static struct attribute *dci_attrs[] = {
 992         &dev_attr_ni_state.attr,
 993         &dev_attr_packet_bandwidth.attr,
 994         &dev_attr_node_address.attr,
 995         &dev_attr_node_position.attr,
 996         &dev_attr_sync_ep.attr,
 997         &dev_attr_mep_filter.attr,
 998         &dev_attr_mep_hash0.attr,
 999         &dev_attr_mep_hash1.attr,
1000         &dev_attr_mep_hash2.attr,
1001         &dev_attr_mep_hash3.attr,
1002         &dev_attr_mep_eui48_hi.attr,
1003         &dev_attr_mep_eui48_mi.attr,
1004         &dev_attr_mep_eui48_lo.attr,
1005         &dev_attr_arb_address.attr,
1006         &dev_attr_arb_value.attr,
1007         NULL,
1008 };
1009
1010 static struct attribute_group dci_attr_group = {
1011         .attrs = dci_attrs,
1012 };
1013
1014 static const struct attribute_group *dci_attr_groups[] = {
1015         &dci_attr_group,
1016         NULL,
1017 };
1018
1019 static void release_dci(struct device *dev)
1020 {
1021         struct most_dci_obj *dci = to_dci_obj(dev);
1022
1023         kfree(dci);
1024 }
1025
1026 /**
1027  * hdm_probe - probe function of USB device driver
1028  * @interface: Interface of the attached USB device
1029  * @id: Pointer to the USB ID table.
1030  *
1031  * This allocates and initializes the device instance, adds the new
1032  * entry to the internal list, scans the USB descriptors and registers
1033  * the interface with the core.
1034  * Additionally, the DCI objects are created and the hardware is sync'd.
1035  *
1036  * Return 0 on success. In case of an error a negative number is returned.
1037  */
1038 static int
1039 hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
1040 {
1041         struct usb_host_interface *usb_iface_desc = interface->cur_altsetting;
1042         struct usb_device *usb_dev = interface_to_usbdev(interface);
1043         struct device *dev = &usb_dev->dev;
1044         struct most_dev *mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1045         unsigned int i;
1046         unsigned int num_endpoints;
1047         struct most_channel_capability *tmp_cap;
1048         struct usb_endpoint_descriptor *ep_desc;
1049         int ret = 0;
1050
1051         if (!mdev)
1052                 goto err_out_of_memory;
1053
1054         usb_set_intfdata(interface, mdev);
1055         num_endpoints = usb_iface_desc->desc.bNumEndpoints;
1056         mutex_init(&mdev->io_mutex);
1057         INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
1058         timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);
1059
1060         mdev->usb_device = usb_dev;
1061         mdev->link_stat_timer.expires = jiffies + (2 * HZ);
1062
1063         mdev->iface.mod = hdm_usb_fops.owner;
1064         mdev->iface.driver_dev = &interface->dev;
1065         mdev->iface.interface = ITYPE_USB;
1066         mdev->iface.configure = hdm_configure_channel;
1067         mdev->iface.request_netinfo = hdm_request_netinfo;
1068         mdev->iface.enqueue = hdm_enqueue;
1069         mdev->iface.poison_channel = hdm_poison_channel;
1070         mdev->iface.dma_alloc = hdm_dma_alloc;
1071         mdev->iface.dma_free = hdm_dma_free;
1072         mdev->iface.description = mdev->description;
1073         mdev->iface.num_channels = num_endpoints;
1074
1075         snprintf(mdev->description, sizeof(mdev->description),
1076                  "%d-%s:%d.%d",
1077                  usb_dev->bus->busnum,
1078                  usb_dev->devpath,
1079                  usb_dev->config->desc.bConfigurationValue,
1080                  usb_iface_desc->desc.bInterfaceNumber);
1081
1082         mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
1083         if (!mdev->conf)
1084                 goto err_free_mdev;
1085
1086         mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
1087         if (!mdev->cap)
1088                 goto err_free_conf;
1089
1090         mdev->iface.channel_vector = mdev->cap;
1091         mdev->ep_address =
1092                 kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
1093         if (!mdev->ep_address)
1094                 goto err_free_cap;
1095
1096         mdev->busy_urbs =
1097                 kcalloc(num_endpoints, sizeof(*mdev->busy_urbs), GFP_KERNEL);
1098         if (!mdev->busy_urbs)
1099                 goto err_free_ep_address;
1100
1101         tmp_cap = mdev->cap;
1102         for (i = 0; i < num_endpoints; i++) {
1103                 ep_desc = &usb_iface_desc->endpoint[i].desc;
1104                 mdev->ep_address[i] = ep_desc->bEndpointAddress;
1105                 mdev->padding_active[i] = false;
1106                 mdev->is_channel_healthy[i] = true;
1107
1108                 snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
1109                          mdev->ep_address[i]);
1110
1111                 tmp_cap->name_suffix = &mdev->suffix[i][0];
1112                 tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
1113                 tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
1114                 tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
1115                 tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
1116                 tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
1117                                      MOST_CH_ISOC | MOST_CH_SYNC;
1118                 if (usb_endpoint_dir_in(ep_desc))
1119                         tmp_cap->direction = MOST_CH_RX;
1120                 else
1121                         tmp_cap->direction = MOST_CH_TX;
1122                 tmp_cap++;
1123                 init_usb_anchor(&mdev->busy_urbs[i]);
1124                 spin_lock_init(&mdev->channel_lock[i]);
1125         }
1126         dev_notice(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
1127                    le16_to_cpu(usb_dev->descriptor.idVendor),
1128                    le16_to_cpu(usb_dev->descriptor.idProduct),
1129                    usb_dev->bus->busnum,
1130                    usb_dev->devnum);
1131
1132         dev_notice(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
1133                    usb_dev->bus->busnum,
1134                    usb_dev->devpath,
1135                    usb_dev->config->desc.bConfigurationValue,
1136                    usb_iface_desc->desc.bInterfaceNumber);
1137
1138         ret = most_register_interface(&mdev->iface);
1139         if (ret)
1140                 goto err_free_busy_urbs;
1141
1142         mutex_lock(&mdev->io_mutex);
1143         if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
1144             le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81119 ||
1145             le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81210) {
1146                 mdev->dci = kzalloc(sizeof(*mdev->dci), GFP_KERNEL);
1147                 if (!mdev->dci) {
1148                         mutex_unlock(&mdev->io_mutex);
1149                         most_deregister_interface(&mdev->iface);
1150                         ret = -ENOMEM;
1151                         goto err_free_busy_urbs;
1152                 }
1153
1154                 mdev->dci->dev.init_name = "dci";
1155                 mdev->dci->dev.parent = &mdev->iface.dev;
1156                 mdev->dci->dev.groups = dci_attr_groups;
1157                 mdev->dci->dev.release = release_dci;
1158                 if (device_register(&mdev->dci->dev)) {
1159                         mutex_unlock(&mdev->io_mutex);
1160                         most_deregister_interface(&mdev->iface);
1161                         ret = -ENOMEM;
1162                         goto err_free_dci;
1163                 }
1164                 mdev->dci->usb_device = mdev->usb_device;
1165         }
1166         mutex_unlock(&mdev->io_mutex);
1167         return 0;
1168 err_free_dci:
1169         kfree(mdev->dci);
1170 err_free_busy_urbs:
1171         kfree(mdev->busy_urbs);
1172 err_free_ep_address:
1173         kfree(mdev->ep_address);
1174 err_free_cap:
1175         kfree(mdev->cap);
1176 err_free_conf:
1177         kfree(mdev->conf);
1178 err_free_mdev:
1179         kfree(mdev);
1180 err_out_of_memory:
1181         if (ret == 0 || ret == -ENOMEM) {
1182                 ret = -ENOMEM;
1183                 dev_err(dev, "out of memory\n");
1184         }
1185         return ret;
1186 }
1187
1188 /**
1189  * hdm_disconnect - disconnect function of USB device driver
1190  * @interface: Interface of the attached USB device
1191  *
1192  * This deregisters the interface with the core, removes the kernel timer
1193  * and frees resources.
1194  *
1195  * Context: hub kernel thread
1196  */
1197 static void hdm_disconnect(struct usb_interface *interface)
1198 {
1199         struct most_dev *mdev = usb_get_intfdata(interface);
1200
1201         mutex_lock(&mdev->io_mutex);
1202         usb_set_intfdata(interface, NULL);
1203         mdev->usb_device = NULL;
1204         mutex_unlock(&mdev->io_mutex);
1205
1206         del_timer_sync(&mdev->link_stat_timer);
1207         cancel_work_sync(&mdev->poll_work_obj);
1208
1209         device_unregister(&mdev->dci->dev);
1210         most_deregister_interface(&mdev->iface);
1211
1212         kfree(mdev->busy_urbs);
1213         kfree(mdev->cap);
1214         kfree(mdev->conf);
1215         kfree(mdev->ep_address);
1216         kfree(mdev);
1217 }
1218
1219 static struct usb_driver hdm_usb = {
1220         .name = "hdm_usb",
1221         .id_table = usbid,
1222         .probe = hdm_probe,
1223         .disconnect = hdm_disconnect,
1224 };
1225
1226 module_usb_driver(hdm_usb);
1227 MODULE_LICENSE("GPL");
1228 MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
1229 MODULE_DESCRIPTION("HDM_4_USB");