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