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 device dev;
 106         struct usb_device *usb_device;
 107         struct most_interface iface;
 108         struct most_channel_capability *cap;
 109         struct most_channel_config *conf;
 110         struct most_dci_obj *dci;
 111         u8 *ep_address;
 112         char description[MAX_STRING_LEN];
 113         char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
 114         spinlock_t channel_lock[MAX_NUM_ENDPOINTS]; /* sync channel access */
 115         bool padding_active[MAX_NUM_ENDPOINTS];
 116         bool is_channel_healthy[MAX_NUM_ENDPOINTS];
 117         struct clear_hold_work clear_work[MAX_NUM_ENDPOINTS];
 118         struct usb_anchor *busy_urbs;
 119         struct mutex io_mutex;
 120         struct timer_list link_stat_timer;
 121         struct work_struct poll_work_obj;
 122         void (*on_netinfo)(struct most_interface *most_iface,
 123                            unsigned char link_state, unsigned char *addrs);
 124 };
 125
 126 #define to_mdev(d) container_of(d, struct most_dev, iface)
 127 #define to_mdev_from_dev(d) container_of(d, struct most_dev, dev)
 128 #define to_mdev_from_work(w) container_of(w, struct most_dev, poll_work_obj)
 129
 130 static void wq_clear_halt(struct work_struct *wq_obj);
 131 static void wq_netinfo(struct work_struct *wq_obj);
 132
 133 /**
 134  * drci_rd_reg - read a DCI register
 135  * @dev: usb device
 136  * @reg: register address
 137  * @buf: buffer to store data
 138  *
 139  * This is reads data from INIC's direct register communication interface
 140  */
 141 static inline int drci_rd_reg(struct usb_device *dev, u16 reg, u16 *buf)
 142 {
 143         int retval;
 144         __le16 *dma_buf = kzalloc(sizeof(*dma_buf), GFP_KERNEL);
 145         u8 req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
 146
 147         if (!dma_buf)
 148                 return -ENOMEM;
 149
 150         retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 151                                  DRCI_READ_REQ, req_type,
 152                                  0x0000,
 153                                  reg, dma_buf, sizeof(*dma_buf), 5 * HZ);
 154         *buf = le16_to_cpu(*dma_buf);
 155         kfree(dma_buf);
 156
 157         return retval;
 158 }
 159
 160 /**
 161  * drci_wr_reg - write a DCI register
 162  * @dev: usb device
 163  * @reg: register address
 164  * @data: data to write
 165  *
 166  * This is writes data to INIC's direct register communication interface
 167  */
 168 static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
 169 {
 170         return usb_control_msg(dev,
 171                                usb_sndctrlpipe(dev, 0),
 172                                DRCI_WRITE_REQ,
 173                                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 174                                data,
 175                                reg,
 176                                NULL,
 177                                0,
 178                                5 * HZ);
 179 }
 180
 181 static inline int start_sync_ep(struct usb_device *usb_dev, u16 ep)
 182 {
 183         return drci_wr_reg(usb_dev, DRCI_REG_BASE + DRCI_COMMAND + ep * 16, 1);
 184 }
 185
 186 /**
 187  * get_stream_frame_size - calculate frame size of current configuration
 188  * @cfg: channel configuration
 189  */
 190 static unsigned int get_stream_frame_size(struct most_channel_config *cfg)
 191 {
 192         unsigned int frame_size = 0;
 193         unsigned int sub_size = cfg->subbuffer_size;
 194
 195         if (!sub_size) {
 196                 pr_warn("Misconfig: Subbuffer size zero.\n");
 197                 return frame_size;
 198         }
 199         switch (cfg->data_type) {
 200         case MOST_CH_ISOC:
 201                 frame_size = AV_PACKETS_PER_XACT * sub_size;
 202                 break;
 203         case MOST_CH_SYNC:
 204                 if (cfg->packets_per_xact == 0) {
 205                         pr_warn("Misconfig: Packets per XACT zero\n");
 206                         frame_size = 0;
 207                 } else if (cfg->packets_per_xact == 0xFF) {
 208                         frame_size = (USB_MTU / sub_size) * sub_size;
 209                 } else {
 210                         frame_size = cfg->packets_per_xact * sub_size;
 211                 }
 212                 break;
 213         default:
 214                 pr_warn("Query frame size of non-streaming channel\n");
 215                 break;
 216         }
 217         return frame_size;
 218 }
 219
 220 /**
 221  * hdm_poison_channel - mark buffers of this channel as invalid
 222  * @iface: pointer to the interface
 223  * @channel: channel ID
 224  *
 225  * This unlinks all URBs submitted to the HCD,
 226  * calls the associated completion function of the core and removes
 227  * them from the list.
 228  *
 229  * Returns 0 on success or error code otherwise.
 230  */
 231 static int hdm_poison_channel(struct most_interface *iface, int channel)
 232 {
 233         struct most_dev *mdev = to_mdev(iface);
 234         unsigned long flags;
 235         spinlock_t *lock; /* temp. lock */
 236
 237         if (unlikely(!iface)) {
 238                 dev_warn(&mdev->usb_device->dev, "Poison: Bad interface.\n");
 239                 return -EIO;
 240         }
 241         if (unlikely(channel < 0 || channel >= iface->num_channels)) {
 242                 dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
 243                 return -ECHRNG;
 244         }
 245
 246         lock = mdev->channel_lock + channel;
 247         spin_lock_irqsave(lock, flags);
 248         mdev->is_channel_healthy[channel] = false;
 249         spin_unlock_irqrestore(lock, flags);
 250
 251         cancel_work_sync(&mdev->clear_work[channel].ws);
 252
 253         mutex_lock(&mdev->io_mutex);
 254         usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
 255         if (mdev->padding_active[channel])
 256                 mdev->padding_active[channel] = false;
 257
 258         if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
 259                 del_timer_sync(&mdev->link_stat_timer);
 260                 cancel_work_sync(&mdev->poll_work_obj);
 261         }
 262         mutex_unlock(&mdev->io_mutex);
 263         return 0;
 264 }
 265
 266 /**
 267  * hdm_add_padding - add padding bytes
 268  * @mdev: most device
 269  * @channel: channel ID
 270  * @mbo: buffer object
 271  *
 272  * This inserts the INIC hardware specific padding bytes into a streaming
 273  * channel's buffer
 274  */
 275 static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
 276 {
 277         struct most_channel_config *conf = &mdev->conf[channel];
 278         unsigned int frame_size = get_stream_frame_size(conf);
 279         unsigned int j, num_frames;
 280
 281         if (!frame_size)
 282                 return -EIO;
 283         num_frames = mbo->buffer_length / frame_size;
 284
 285         if (num_frames < 1) {
 286                 dev_err(&mdev->usb_device->dev,
 287                         "Missed minimal transfer unit.\n");
 288                 return -EIO;
 289         }
 290
 291         for (j = num_frames - 1; j > 0; j--)
 292                 memmove(mbo->virt_address + j * USB_MTU,
 293                         mbo->virt_address + j * frame_size,
 294                         frame_size);
 295         mbo->buffer_length = num_frames * USB_MTU;
 296         return 0;
 297 }
 298
 299 /**
 300  * hdm_remove_padding - remove padding bytes
 301  * @mdev: most device
 302  * @channel: channel ID
 303  * @mbo: buffer object
 304  *
 305  * This takes the INIC hardware specific padding bytes off a streaming
 306  * channel's buffer.
 307  */
 308 static int hdm_remove_padding(struct most_dev *mdev, int channel,
 309                               struct mbo *mbo)
 310 {
 311         struct most_channel_config *const conf = &mdev->conf[channel];
 312         unsigned int frame_size = get_stream_frame_size(conf);
 313         unsigned int j, num_frames;
 314
 315         if (!frame_size)
 316                 return -EIO;
 317         num_frames = mbo->processed_length / USB_MTU;
 318
 319         for (j = 1; j < num_frames; j++)
 320                 memmove(mbo->virt_address + frame_size * j,
 321                         mbo->virt_address + USB_MTU * j,
 322                         frame_size);
 323
 324         mbo->processed_length = frame_size * num_frames;
 325         return 0;
 326 }
 327
 328 /**
 329  * hdm_write_completion - completion function for submitted Tx URBs
 330  * @urb: the URB that has been completed
 331  *
 332  * This checks the status of the completed URB. In case the URB has been
 333  * unlinked before, it is immediately freed. On any other error the MBO
 334  * transfer flag is set. On success it frees allocated resources and calls
 335  * the completion function.
 336  *
 337  * Context: interrupt!
 338  */
 339 static void hdm_write_completion(struct urb *urb)
 340 {
 341         struct mbo *mbo = urb->context;
 342         struct most_dev *mdev = to_mdev(mbo->ifp);
 343         unsigned int channel = mbo->hdm_channel_id;
 344         spinlock_t *lock = mdev->channel_lock + channel;
 345         unsigned long flags;
 346
 347         spin_lock_irqsave(lock, flags);
 348
 349         mbo->processed_length = 0;
 350         mbo->status = MBO_E_INVAL;
 351         if (likely(mdev->is_channel_healthy[channel])) {
 352                 switch (urb->status) {
 353                 case 0:
 354                 case -ESHUTDOWN:
 355                         mbo->processed_length = urb->actual_length;
 356                         mbo->status = MBO_SUCCESS;
 357                         break;
 358                 case -EPIPE:
 359                         dev_warn(&mdev->usb_device->dev,
 360                                  "Broken pipe on ep%02x\n",
 361                                  mdev->ep_address[channel]);
 362                         mdev->is_channel_healthy[channel] = false;
 363                         mdev->clear_work[channel].pipe = urb->pipe;
 364                         schedule_work(&mdev->clear_work[channel].ws);
 365                         break;
 366                 case -ENODEV:
 367                 case -EPROTO:
 368                         mbo->status = MBO_E_CLOSE;
 369                         break;
 370                 }
 371         }
 372
 373         spin_unlock_irqrestore(lock, flags);
 374
 375         if (likely(mbo->complete))
 376                 mbo->complete(mbo);
 377         usb_free_urb(urb);
 378 }
 379
 380 /**
 381  * hdm_read_completion - completion function for submitted Rx URBs
 382  * @urb: the URB that has been completed
 383  *
 384  * This checks the status of the completed URB. In case the URB has been
 385  * unlinked before it is immediately freed. On any other error the MBO transfer
 386  * flag is set. On success it frees allocated resources, removes
 387  * padding bytes -if necessary- and calls the completion function.
 388  *
 389  * Context: interrupt!
 390  *
 391  * **************************************************************************
 392  *                   Error codes returned by in urb->status
 393  *                   or in iso_frame_desc[n].status (for ISO)
 394  * *************************************************************************
 395  *
 396  * USB device drivers may only test urb status values in completion handlers.
 397  * This is because otherwise there would be a race between HCDs updating
 398  * these values on one CPU, and device drivers testing them on another CPU.
 399  *
 400  * A transfer's actual_length may be positive even when an error has been
 401  * reported.  That's because transfers often involve several packets, so that
 402  * one or more packets could finish before an error stops further endpoint I/O.
 403  *
 404  * For isochronous URBs, the urb status value is non-zero only if the URB is
 405  * unlinked, the device is removed, the host controller is disabled or the total
 406  * transferred length is less than the requested length and the URB_SHORT_NOT_OK
 407  * flag is set.  Completion handlers for isochronous URBs should only see
 408  * urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
 409  * Individual frame descriptor status fields may report more status codes.
 410  *
 411  *
 412  * 0                    Transfer completed successfully
 413  *
 414  * -ENOENT              URB was synchronously unlinked by usb_unlink_urb
 415  *
 416  * -EINPROGRESS         URB still pending, no results yet
 417  *                      (That is, if drivers see this it's a bug.)
 418  *
 419  * -EPROTO (*, **)      a) bitstuff error
 420  *                      b) no response packet received within the
 421  *                         prescribed bus turn-around time
 422  *                      c) unknown USB error
 423  *
 424  * -EILSEQ (*, **)      a) CRC mismatch
 425  *                      b) no response packet received within the
 426  *                         prescribed bus turn-around time
 427  *                      c) unknown USB error
 428  *
 429  *                      Note that often the controller hardware does not
 430  *                      distinguish among cases a), b), and c), so a
 431  *                      driver cannot tell whether there was a protocol
 432  *                      error, a failure to respond (often caused by
 433  *                      device disconnect), or some other fault.
 434  *
 435  * -ETIME (**)          No response packet received within the prescribed
 436  *                      bus turn-around time.  This error may instead be
 437  *                      reported as -EPROTO or -EILSEQ.
 438  *
 439  * -ETIMEDOUT           Synchronous USB message functions use this code
 440  *                      to indicate timeout expired before the transfer
 441  *                      completed, and no other error was reported by HC.
 442  *
 443  * -EPIPE (**)          Endpoint stalled.  For non-control endpoints,
 444  *                      reset this status with usb_clear_halt().
 445  *
 446  * -ECOMM               During an IN transfer, the host controller
 447  *                      received data from an endpoint faster than it
 448  *                      could be written to system memory
 449  *
 450  * -ENOSR               During an OUT transfer, the host controller
 451  *                      could not retrieve data from system memory fast
 452  *                      enough to keep up with the USB data rate
 453  *
 454  * -EOVERFLOW (*)       The amount of data returned by the endpoint was
 455  *                      greater than either the max packet size of the
 456  *                      endpoint or the remaining buffer size.  "Babble".
 457  *
 458  * -EREMOTEIO           The data read from the endpoint did not fill the
 459  *                      specified buffer, and URB_SHORT_NOT_OK was set in
 460  *                      urb->transfer_flags.
 461  *
 462  * -ENODEV              Device was removed.  Often preceded by a burst of
 463  *                      other errors, since the hub driver doesn't detect
 464  *                      device removal events immediately.
 465  *
 466  * -EXDEV               ISO transfer only partially completed
 467  *                      (only set in iso_frame_desc[n].status, not urb->status)
 468  *
 469  * -EINVAL              ISO madness, if this happens: Log off and go home
 470  *
 471  * -ECONNRESET          URB was asynchronously unlinked by usb_unlink_urb
 472  *
 473  * -ESHUTDOWN           The device or host controller has been disabled due
 474  *                      to some problem that could not be worked around,
 475  *                      such as a physical disconnect.
 476  *
 477  *
 478  * (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
 479  * hardware problems such as bad devices (including firmware) or cables.
 480  *
 481  * (**) This is also one of several codes that different kinds of host
 482  * controller use to indicate a transfer has failed because of device
 483  * disconnect.  In the interval before the hub driver starts disconnect
 484  * processing, devices may receive such fault reports for every request.
 485  *
 486  * See <https://www.kernel.org/doc/Documentation/driver-api/usb/error-codes.rst>
 487  */
 488 static void hdm_read_completion(struct urb *urb)
 489 {
 490         struct mbo *mbo = urb->context;
 491         struct most_dev *mdev = to_mdev(mbo->ifp);
 492         unsigned int channel = mbo->hdm_channel_id;
 493         struct device *dev = &mdev->usb_device->dev;
 494         spinlock_t *lock = mdev->channel_lock + channel;
 495         unsigned long flags;
 496
 497         spin_lock_irqsave(lock, flags);
 498
 499         mbo->processed_length = 0;
 500         mbo->status = MBO_E_INVAL;
 501         if (likely(mdev->is_channel_healthy[channel])) {
 502                 switch (urb->status) {
 503                 case 0:
 504                 case -ESHUTDOWN:
 505                         mbo->processed_length = urb->actual_length;
 506                         mbo->status = MBO_SUCCESS;
 507                         if (mdev->padding_active[channel] &&
 508                             hdm_remove_padding(mdev, channel, mbo)) {
 509                                 mbo->processed_length = 0;
 510                                 mbo->status = MBO_E_INVAL;
 511                         }
 512                         break;
 513                 case -EPIPE:
 514                         dev_warn(dev, "Broken pipe on ep%02x\n",
 515                                  mdev->ep_address[channel]);
 516                         mdev->is_channel_healthy[channel] = false;
 517                         mdev->clear_work[channel].pipe = urb->pipe;
 518                         schedule_work(&mdev->clear_work[channel].ws);
 519                         break;
 520                 case -ENODEV:
 521                 case -EPROTO:
 522                         mbo->status = MBO_E_CLOSE;
 523                         break;
 524                 case -EOVERFLOW:
 525                         dev_warn(dev, "Babble on ep%02x\n",
 526                                  mdev->ep_address[channel]);
 527                         break;
 528                 }
 529         }
 530
 531         spin_unlock_irqrestore(lock, flags);
 532
 533         if (likely(mbo->complete))
 534                 mbo->complete(mbo);
 535         usb_free_urb(urb);
 536 }
 537
 538 /**
 539  * hdm_enqueue - receive a buffer to be used for data transfer
 540  * @iface: interface to enqueue to
 541  * @channel: ID of the channel
 542  * @mbo: pointer to the buffer object
 543  *
 544  * This allocates a new URB and fills it according to the channel
 545  * that is being used for transmission of data. Before the URB is
 546  * submitted it is stored in the private anchor list.
 547  *
 548  * Returns 0 on success. On any error the URB is freed and a error code
 549  * is returned.
 550  *
 551  * Context: Could in _some_ cases be interrupt!
 552  */
 553 static int hdm_enqueue(struct most_interface *iface, int channel,
 554                        struct mbo *mbo)
 555 {
 556         struct most_dev *mdev;
 557         struct most_channel_config *conf;
 558         int retval = 0;
 559         struct urb *urb;
 560         unsigned long length;
 561         void *virt_address;
 562
 563         if (unlikely(!iface || !mbo))
 564                 return -EIO;
 565         if (unlikely(iface->num_channels <= channel || channel < 0))
 566                 return -ECHRNG;
 567
 568         mdev = to_mdev(iface);
 569         conf = &mdev->conf[channel];
 570
 571         mutex_lock(&mdev->io_mutex);
 572         if (!mdev->usb_device) {
 573                 retval = -ENODEV;
 574                 goto unlock_io_mutex;
 575         }
 576
 577         urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_ATOMIC);
 578         if (!urb) {
 579                 retval = -ENOMEM;
 580                 goto unlock_io_mutex;
 581         }
 582
 583         if ((conf->direction & MOST_CH_TX) && mdev->padding_active[channel] &&
 584             hdm_add_padding(mdev, channel, mbo)) {
 585                 retval = -EIO;
 586                 goto err_free_urb;
 587         }
 588
 589         urb->transfer_dma = mbo->bus_address;
 590         virt_address = mbo->virt_address;
 591         length = mbo->buffer_length;
 592
 593         if (conf->direction & MOST_CH_TX) {
 594                 usb_fill_bulk_urb(urb, mdev->usb_device,
 595                                   usb_sndbulkpipe(mdev->usb_device,
 596                                                   mdev->ep_address[channel]),
 597                                   virt_address,
 598                                   length,
 599                                   hdm_write_completion,
 600                                   mbo);
 601                 if (conf->data_type != MOST_CH_ISOC &&
 602                     conf->data_type != MOST_CH_SYNC)
 603                         urb->transfer_flags |= URB_ZERO_PACKET;
 604         } else {
 605                 usb_fill_bulk_urb(urb, mdev->usb_device,
 606                                   usb_rcvbulkpipe(mdev->usb_device,
 607                                                   mdev->ep_address[channel]),
 608                                   virt_address,
 609                                   length + conf->extra_len,
 610                                   hdm_read_completion,
 611                                   mbo);
 612         }
 613         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 614
 615         usb_anchor_urb(urb, &mdev->busy_urbs[channel]);
 616
 617         retval = usb_submit_urb(urb, GFP_KERNEL);
 618         if (retval) {
 619                 dev_err(&mdev->usb_device->dev,
 620                         "URB submit failed with error %d.\n", retval);
 621                 goto err_unanchor_urb;
 622         }
 623         goto unlock_io_mutex;
 624
 625 err_unanchor_urb:
 626         usb_unanchor_urb(urb);
 627 err_free_urb:
 628         usb_free_urb(urb);
 629 unlock_io_mutex:
 630         mutex_unlock(&mdev->io_mutex);
 631         return retval;
 632 }
 633
 634 static void *hdm_dma_alloc(struct mbo *mbo, u32 size)
 635 {
 636         struct most_dev *mdev = to_mdev(mbo->ifp);
 637
 638         return usb_alloc_coherent(mdev->usb_device, size, GFP_KERNEL,
 639                                   &mbo->bus_address);
 640 }
 641
 642 static void hdm_dma_free(struct mbo *mbo, u32 size)
 643 {
 644         struct most_dev *mdev = to_mdev(mbo->ifp);
 645
 646         usb_free_coherent(mdev->usb_device, size, mbo->virt_address,
 647                           mbo->bus_address);
 648 }
 649
 650 /**
 651  * hdm_configure_channel - receive channel configuration from core
 652  * @iface: interface
 653  * @channel: channel ID
 654  * @conf: structure that holds the configuration information
 655  *
 656  * The attached network interface controller (NIC) supports a padding mode
 657  * to avoid short packets on USB, hence increasing the performance due to a
 658  * lower interrupt load. This mode is default for synchronous data and can
 659  * be switched on for isochronous data. In case padding is active the
 660  * driver needs to know the frame size of the payload in order to calculate
 661  * the number of bytes it needs to pad when transmitting or to cut off when
 662  * receiving data.
 663  *
 664  */
 665 static int hdm_configure_channel(struct most_interface *iface, int channel,
 666                                  struct most_channel_config *conf)
 667 {
 668         unsigned int num_frames;
 669         unsigned int frame_size;
 670         struct most_dev *mdev = to_mdev(iface);
 671         struct device *dev = &mdev->usb_device->dev;
 672
 673         mdev->is_channel_healthy[channel] = true;
 674         mdev->clear_work[channel].channel = channel;
 675         mdev->clear_work[channel].mdev = mdev;
 676         INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
 677
 678         if (unlikely(!iface || !conf)) {
 679                 dev_err(dev, "Bad interface or config pointer.\n");
 680                 return -EINVAL;
 681         }
 682         if (unlikely(channel < 0 || channel >= iface->num_channels)) {
 683                 dev_err(dev, "Channel ID out of range.\n");
 684                 return -EINVAL;
 685         }
 686         if (!conf->num_buffers || !conf->buffer_size) {
 687                 dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
 688                 return -EINVAL;
 689         }
 690
 691         if (conf->data_type != MOST_CH_SYNC &&
 692             !(conf->data_type == MOST_CH_ISOC &&
 693               conf->packets_per_xact != 0xFF)) {
 694                 mdev->padding_active[channel] = false;
 695                 /*
 696                  * Since the NIC's padding mode is not going to be
 697                  * used, we can skip the frame size calculations and
 698                  * move directly on to exit.
 699                  */
 700                 goto exit;
 701         }
 702
 703         mdev->padding_active[channel] = true;
 704
 705         frame_size = get_stream_frame_size(conf);
 706         if (frame_size == 0 || frame_size > USB_MTU) {
 707                 dev_warn(dev, "Misconfig: frame size wrong\n");
 708                 return -EINVAL;
 709         }
 710
 711         num_frames = conf->buffer_size / frame_size;
 712
 713         if (conf->buffer_size % frame_size) {
 714                 u16 old_size = conf->buffer_size;
 715
 716                 conf->buffer_size = num_frames * frame_size;
 717                 dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
 718                          mdev->suffix[channel], old_size, conf->buffer_size);
 719         }
 720
 721         /* calculate extra length to comply w/ HW padding */
 722         conf->extra_len = num_frames * (USB_MTU - frame_size);
 723
 724 exit:
 725         mdev->conf[channel] = *conf;
 726         if (conf->data_type == MOST_CH_ASYNC) {
 727                 u16 ep = mdev->ep_address[channel];
 728
 729                 if (start_sync_ep(mdev->usb_device, ep) < 0)
 730                         dev_warn(dev, "sync for ep%02x failed", ep);
 731         }
 732         return 0;
 733 }
 734
 735 /**
 736  * hdm_request_netinfo - request network information
 737  * @iface: pointer to interface
 738  * @channel: channel ID
 739  *
 740  * This is used as trigger to set up the link status timer that
 741  * polls for the NI state of the INIC every 2 seconds.
 742  *
 743  */
 744 static void hdm_request_netinfo(struct most_interface *iface, int channel,
 745                                 void (*on_netinfo)(struct most_interface *,
 746                                                    unsigned char,
 747                                                    unsigned char *))
 748 {
 749         struct most_dev *mdev;
 750
 751         BUG_ON(!iface);
 752         mdev = to_mdev(iface);
 753         mdev->on_netinfo = on_netinfo;
 754         if (!on_netinfo)
 755                 return;
 756
 757         mdev->link_stat_timer.expires = jiffies + HZ;
 758         mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
 759 }
 760
 761 /**
 762  * link_stat_timer_handler - schedule work obtaining mac address and link status
 763  * @data: pointer to USB device instance
 764  *
 765  * The handler runs in interrupt context. That's why we need to defer the
 766  * tasks to a work queue.
 767  */
 768 static void link_stat_timer_handler(struct timer_list *t)
 769 {
 770         struct most_dev *mdev = from_timer(mdev, t, link_stat_timer);
 771
 772         schedule_work(&mdev->poll_work_obj);
 773         mdev->link_stat_timer.expires = jiffies + (2 * HZ);
 774         add_timer(&mdev->link_stat_timer);
 775 }
 776
 777 /**
 778  * wq_netinfo - work queue function to deliver latest networking information
 779  * @wq_obj: object that holds data for our deferred work to do
 780  *
 781  * This retrieves the network interface status of the USB INIC
 782  */
 783 static void wq_netinfo(struct work_struct *wq_obj)
 784 {
 785         struct most_dev *mdev = to_mdev_from_work(wq_obj);
 786         struct usb_device *usb_device = mdev->usb_device;
 787         struct device *dev = &usb_device->dev;
 788         u16 hi, mi, lo, link;
 789         u8 hw_addr[6];
 790
 791         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi) < 0) {
 792                 dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
 793                 return;
 794         }
 795
 796         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi) < 0) {
 797                 dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
 798                 return;
 799         }
 800
 801         if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo) < 0) {
 802                 dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
 803                 return;
 804         }
 805
 806         if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link) < 0) {
 807                 dev_err(dev, "Vendor request 'link status' failed\n");
 808                 return;
 809         }
 810
 811         hw_addr[0] = hi >> 8;
 812         hw_addr[1] = hi;
 813         hw_addr[2] = mi >> 8;
 814         hw_addr[3] = mi;
 815         hw_addr[4] = lo >> 8;
 816         hw_addr[5] = lo;
 817
 818         if (mdev->on_netinfo)
 819                 mdev->on_netinfo(&mdev->iface, link, hw_addr);
 820 }
 821
 822 /**
 823  * wq_clear_halt - work queue function
 824  * @wq_obj: work_struct object to execute
 825  *
 826  * This sends a clear_halt to the given USB pipe.
 827  */
 828 static void wq_clear_halt(struct work_struct *wq_obj)
 829 {
 830         struct clear_hold_work *clear_work = to_clear_hold_work(wq_obj);
 831         struct most_dev *mdev = clear_work->mdev;
 832         unsigned int channel = clear_work->channel;
 833         int pipe = clear_work->pipe;
 834
 835         mutex_lock(&mdev->io_mutex);
 836         most_stop_enqueue(&mdev->iface, channel);
 837         usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
 838         if (usb_clear_halt(mdev->usb_device, pipe))
 839                 dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");
 840
 841         /* If the functional Stall condition has been set on an
 842          * asynchronous rx channel, we need to clear the tx channel
 843          * too, since the hardware runs its clean-up sequence on both
 844          * channels, as they are physically one on the network.
 845          *
 846          * The USB interface that exposes the asynchronous channels
 847          * contains always two endpoints, and two only.
 848          */
 849         if (mdev->conf[channel].data_type == MOST_CH_ASYNC &&
 850             mdev->conf[channel].direction == MOST_CH_RX) {
 851                 int peer = 1 - channel;
 852                 int snd_pipe = usb_sndbulkpipe(mdev->usb_device,
 853                                                mdev->ep_address[peer]);
 854                 usb_clear_halt(mdev->usb_device, snd_pipe);
 855         }
 856         mdev->is_channel_healthy[channel] = true;
 857         most_resume_enqueue(&mdev->iface, channel);
 858         mutex_unlock(&mdev->io_mutex);
 859 }
 860
 861 /**
 862  * hdm_usb_fops - file operation table for USB driver
 863  */
 864 static const struct file_operations hdm_usb_fops = {
 865         .owner = THIS_MODULE,
 866 };
 867
 868 /**
 869  * usb_device_id - ID table for HCD device probing
 870  */
 871 static const struct usb_device_id usbid[] = {
 872         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
 873         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81118), },
 874         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81119), },
 875         { USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81210), },
 876         { } /* Terminating entry */
 877 };
 878
 879 struct regs {
 880         const char *name;
 881         u16 reg;
 882 };
 883
 884 static const struct regs ro_regs[] = {
 885         { "ni_state", DRCI_REG_NI_STATE },
 886         { "packet_bandwidth", DRCI_REG_PACKET_BW },
 887         { "node_address", DRCI_REG_NODE_ADDR },
 888         { "node_position", DRCI_REG_NODE_POS },
 889 };
 890
 891 static const struct regs rw_regs[] = {
 892         { "mep_filter", DRCI_REG_MEP_FILTER },
 893         { "mep_hash0", DRCI_REG_HASH_TBL0 },
 894         { "mep_hash1", DRCI_REG_HASH_TBL1 },
 895         { "mep_hash2", DRCI_REG_HASH_TBL2 },
 896         { "mep_hash3", DRCI_REG_HASH_TBL3 },
 897         { "mep_eui48_hi", DRCI_REG_HW_ADDR_HI },
 898         { "mep_eui48_mi", DRCI_REG_HW_ADDR_MI },
 899         { "mep_eui48_lo", DRCI_REG_HW_ADDR_LO },
 900 };
 901
 902 static int get_stat_reg_addr(const struct regs *regs, int size,
 903                              const char *name, u16 *reg_addr)
 904 {
 905         int i;
 906
 907         for (i = 0; i < size; i++) {
 908                 if (!strcmp(name, regs[i].name)) {
 909                         *reg_addr = regs[i].reg;
 910                         return 0;
 911                 }
 912         }
 913         return -EFAULT;
 914 }
 915
 916 #define get_static_reg_addr(regs, name, reg_addr) \
 917         get_stat_reg_addr(regs, ARRAY_SIZE(regs), name, reg_addr)
 918
 919 static ssize_t value_show(struct device *dev, struct device_attribute *attr,
 920                           char *buf)
 921 {
 922         const char *name = attr->attr.name;
 923         struct most_dci_obj *dci_obj = to_dci_obj(dev);
 924         u16 val;
 925         u16 reg_addr;
 926         int err;
 927
 928         if (!strcmp(name, "arb_address"))
 929                 return snprintf(buf, PAGE_SIZE, "%04x\n", dci_obj->reg_addr);
 930
 931         if (!strcmp(name, "arb_value"))
 932                 reg_addr = dci_obj->reg_addr;
 933         else if (get_static_reg_addr(ro_regs, name, &reg_addr) &&
 934                  get_static_reg_addr(rw_regs, name, &reg_addr))
 935                 return -EFAULT;
 936
 937         err = drci_rd_reg(dci_obj->usb_device, reg_addr, &val);
 938         if (err < 0)
 939                 return err;
 940
 941         return snprintf(buf, PAGE_SIZE, "%04x\n", val);
 942 }
 943
 944 static ssize_t value_store(struct device *dev, struct device_attribute *attr,
 945                            const char *buf, size_t count)
 946 {
 947         u16 val;
 948         u16 reg_addr;
 949         const char *name = attr->attr.name;
 950         struct most_dci_obj *dci_obj = to_dci_obj(dev);
 951         struct usb_device *usb_dev = dci_obj->usb_device;
 952         int err = kstrtou16(buf, 16, &val);
 953
 954         if (err)
 955                 return err;
 956
 957         if (!strcmp(name, "arb_address")) {
 958                 dci_obj->reg_addr = val;
 959                 return count;
 960         }
 961
 962         if (!strcmp(name, "arb_value"))
 963                 err = drci_wr_reg(usb_dev, dci_obj->reg_addr, val);
 964         else if (!strcmp(name, "sync_ep"))
 965                 err = start_sync_ep(usb_dev, val);
 966         else if (!get_static_reg_addr(rw_regs, name, &reg_addr))
 967                 err = drci_wr_reg(usb_dev, reg_addr, val);
 968         else
 969                 return -EFAULT;
 970
 971         if (err < 0)
 972                 return err;
 973
 974         return count;
 975 }
 976
 977 static DEVICE_ATTR(ni_state, 0444, value_show, NULL);
 978 static DEVICE_ATTR(packet_bandwidth, 0444, value_show, NULL);
 979 static DEVICE_ATTR(node_address, 0444, value_show, NULL);
 980 static DEVICE_ATTR(node_position, 0444, value_show, NULL);
 981 static DEVICE_ATTR(sync_ep, 0200, NULL, value_store);
 982 static DEVICE_ATTR(mep_filter, 0644, value_show, value_store);
 983 static DEVICE_ATTR(mep_hash0, 0644, value_show, value_store);
 984 static DEVICE_ATTR(mep_hash1, 0644, value_show, value_store);
 985 static DEVICE_ATTR(mep_hash2, 0644, value_show, value_store);
 986 static DEVICE_ATTR(mep_hash3, 0644, value_show, value_store);
 987 static DEVICE_ATTR(mep_eui48_hi, 0644, value_show, value_store);
 988 static DEVICE_ATTR(mep_eui48_mi, 0644, value_show, value_store);
 989 static DEVICE_ATTR(mep_eui48_lo, 0644, value_show, value_store);
 990 static DEVICE_ATTR(arb_address, 0644, value_show, value_store);
 991 static DEVICE_ATTR(arb_value, 0644, value_show, value_store);
 992
 993 static struct attribute *dci_attrs[] = {
 994         &dev_attr_ni_state.attr,
 995         &dev_attr_packet_bandwidth.attr,
 996         &dev_attr_node_address.attr,
 997         &dev_attr_node_position.attr,
 998         &dev_attr_sync_ep.attr,
 999         &dev_attr_mep_filter.attr,
1000         &dev_attr_mep_hash0.attr,
1001         &dev_attr_mep_hash1.attr,
1002         &dev_attr_mep_hash2.attr,
1003         &dev_attr_mep_hash3.attr,
1004         &dev_attr_mep_eui48_hi.attr,
1005         &dev_attr_mep_eui48_mi.attr,
1006         &dev_attr_mep_eui48_lo.attr,
1007         &dev_attr_arb_address.attr,
1008         &dev_attr_arb_value.attr,
1009         NULL,
1010 };
1011
1012 static struct attribute_group dci_attr_group = {
1013         .attrs = dci_attrs,
1014 };
1015
1016 static const struct attribute_group *dci_attr_groups[] = {
1017         &dci_attr_group,
1018         NULL,
1019 };
1020
1021 static void release_dci(struct device *dev)
1022 {
1023         struct most_dci_obj *dci = to_dci_obj(dev);
1024
1025         kfree(dci);
1026 }
1027
1028 static void release_mdev(struct device *dev)
1029 {
1030         struct most_dev *mdev = to_mdev_from_dev(dev);
1031
1032         kfree(mdev);
1033 }
1034 /**
1035  * hdm_probe - probe function of USB device driver
1036  * @interface: Interface of the attached USB device
1037  * @id: Pointer to the USB ID table.
1038  *
1039  * This allocates and initializes the device instance, adds the new
1040  * entry to the internal list, scans the USB descriptors and registers
1041  * the interface with the core.
1042  * Additionally, the DCI objects are created and the hardware is sync'd.
1043  *
1044  * Return 0 on success. In case of an error a negative number is returned.
1045  */
1046 static int
1047 hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
1048 {
1049         struct usb_host_interface *usb_iface_desc = interface->cur_altsetting;
1050         struct usb_device *usb_dev = interface_to_usbdev(interface);
1051         struct device *dev = &usb_dev->dev;
1052         struct most_dev *mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1053         unsigned int i;
1054         unsigned int num_endpoints;
1055         struct most_channel_capability *tmp_cap;
1056         struct usb_endpoint_descriptor *ep_desc;
1057         int ret = 0;
1058
1059         if (!mdev)
1060                 goto err_out_of_memory;
1061
1062         usb_set_intfdata(interface, mdev);
1063         num_endpoints = usb_iface_desc->desc.bNumEndpoints;
1064         mutex_init(&mdev->io_mutex);
1065         INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
1066         timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);
1067
1068         mdev->usb_device = usb_dev;
1069         mdev->link_stat_timer.expires = jiffies + (2 * HZ);
1070
1071         mdev->iface.mod = hdm_usb_fops.owner;
1072         mdev->iface.dev = &mdev->dev;
1073         mdev->iface.driver_dev = &interface->dev;
1074         mdev->iface.interface = ITYPE_USB;
1075         mdev->iface.configure = hdm_configure_channel;
1076         mdev->iface.request_netinfo = hdm_request_netinfo;
1077         mdev->iface.enqueue = hdm_enqueue;
1078         mdev->iface.poison_channel = hdm_poison_channel;
1079         mdev->iface.dma_alloc = hdm_dma_alloc;
1080         mdev->iface.dma_free = hdm_dma_free;
1081         mdev->iface.description = mdev->description;
1082         mdev->iface.num_channels = num_endpoints;
1083
1084         snprintf(mdev->description, sizeof(mdev->description),
1085                  "%d-%s:%d.%d",
1086                  usb_dev->bus->busnum,
1087                  usb_dev->devpath,
1088                  usb_dev->config->desc.bConfigurationValue,
1089                  usb_iface_desc->desc.bInterfaceNumber);
1090
1091         mdev->dev.init_name = mdev->description;
1092         mdev->dev.parent = &interface->dev;
1093         mdev->dev.release = release_mdev;
1094         mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
1095         if (!mdev->conf)
1096                 goto err_free_mdev;
1097
1098         mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
1099         if (!mdev->cap)
1100                 goto err_free_conf;
1101
1102         mdev->iface.channel_vector = mdev->cap;
1103         mdev->ep_address =
1104                 kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
1105         if (!mdev->ep_address)
1106                 goto err_free_cap;
1107
1108         mdev->busy_urbs =
1109                 kcalloc(num_endpoints, sizeof(*mdev->busy_urbs), GFP_KERNEL);
1110         if (!mdev->busy_urbs)
1111                 goto err_free_ep_address;
1112
1113         tmp_cap = mdev->cap;
1114         for (i = 0; i < num_endpoints; i++) {
1115                 ep_desc = &usb_iface_desc->endpoint[i].desc;
1116                 mdev->ep_address[i] = ep_desc->bEndpointAddress;
1117                 mdev->padding_active[i] = false;
1118                 mdev->is_channel_healthy[i] = true;
1119
1120                 snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
1121                          mdev->ep_address[i]);
1122
1123                 tmp_cap->name_suffix = &mdev->suffix[i][0];
1124                 tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
1125                 tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
1126                 tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
1127                 tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
1128                 tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
1129                                      MOST_CH_ISOC | MOST_CH_SYNC;
1130                 if (usb_endpoint_dir_in(ep_desc))
1131                         tmp_cap->direction = MOST_CH_RX;
1132                 else
1133                         tmp_cap->direction = MOST_CH_TX;
1134                 tmp_cap++;
1135                 init_usb_anchor(&mdev->busy_urbs[i]);
1136                 spin_lock_init(&mdev->channel_lock[i]);
1137         }
1138         dev_notice(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
1139                    le16_to_cpu(usb_dev->descriptor.idVendor),
1140                    le16_to_cpu(usb_dev->descriptor.idProduct),
1141                    usb_dev->bus->busnum,
1142                    usb_dev->devnum);
1143
1144         dev_notice(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
1145                    usb_dev->bus->busnum,
1146                    usb_dev->devpath,
1147                    usb_dev->config->desc.bConfigurationValue,
1148                    usb_iface_desc->desc.bInterfaceNumber);
1149
1150         ret = most_register_interface(&mdev->iface);
1151         if (ret)
1152                 goto err_free_busy_urbs;
1153
1154         mutex_lock(&mdev->io_mutex);
1155         if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
1156             le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81119 ||
1157             le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81210) {
1158                 mdev->dci = kzalloc(sizeof(*mdev->dci), GFP_KERNEL);
1159                 if (!mdev->dci) {
1160                         mutex_unlock(&mdev->io_mutex);
1161                         most_deregister_interface(&mdev->iface);
1162                         ret = -ENOMEM;
1163                         goto err_free_busy_urbs;
1164                 }
1165
1166                 mdev->dci->dev.init_name = "dci";
1167                 mdev->dci->dev.parent = get_device(mdev->iface.dev);
1168                 mdev->dci->dev.groups = dci_attr_groups;
1169                 mdev->dci->dev.release = release_dci;
1170                 if (device_register(&mdev->dci->dev)) {
1171                         mutex_unlock(&mdev->io_mutex);
1172                         most_deregister_interface(&mdev->iface);
1173                         ret = -ENOMEM;
1174                         goto err_free_dci;
1175                 }
1176                 mdev->dci->usb_device = mdev->usb_device;
1177         }
1178         mutex_unlock(&mdev->io_mutex);
1179         return 0;
1180 err_free_dci:
1181         put_device(&mdev->dci->dev);
1182 err_free_busy_urbs:
1183         kfree(mdev->busy_urbs);
1184 err_free_ep_address:
1185         kfree(mdev->ep_address);
1186 err_free_cap:
1187         kfree(mdev->cap);
1188 err_free_conf:
1189         kfree(mdev->conf);
1190 err_free_mdev:
1191         put_device(&mdev->dev);
1192 err_out_of_memory:
1193         if (ret == 0 || ret == -ENOMEM) {
1194                 ret = -ENOMEM;
1195                 dev_err(dev, "out of memory\n");
1196         }
1197         return ret;
1198 }
1199
1200 /**
1201  * hdm_disconnect - disconnect function of USB device driver
1202  * @interface: Interface of the attached USB device
1203  *
1204  * This deregisters the interface with the core, removes the kernel timer
1205  * and frees resources.
1206  *
1207  * Context: hub kernel thread
1208  */
1209 static void hdm_disconnect(struct usb_interface *interface)
1210 {
1211         struct most_dev *mdev = usb_get_intfdata(interface);
1212
1213         mutex_lock(&mdev->io_mutex);
1214         usb_set_intfdata(interface, NULL);
1215         mdev->usb_device = NULL;
1216         mutex_unlock(&mdev->io_mutex);
1217
1218         del_timer_sync(&mdev->link_stat_timer);
1219         cancel_work_sync(&mdev->poll_work_obj);
1220
1221         if (mdev->dci)
1222                 device_unregister(&mdev->dci->dev);
1223         most_deregister_interface(&mdev->iface);
1224
1225         kfree(mdev->busy_urbs);
1226         kfree(mdev->cap);
1227         kfree(mdev->conf);
1228         kfree(mdev->ep_address);
1229         put_device(&mdev->dev);
1230 }
1231
1232 static struct usb_driver hdm_usb = {
1233         .name = "hdm_usb",
1234         .id_table = usbid,
1235         .probe = hdm_probe,
1236         .disconnect = hdm_disconnect,
1237 };
1238
1239 module_usb_driver(hdm_usb);
1240 MODULE_LICENSE("GPL");
1241 MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
1242 MODULE_DESCRIPTION("HDM_4_USB");