drivers/mfd/dln2.c

   1 /*
   2  * Driver for the Diolan DLN-2 USB adapter
   3  *
   4  * Copyright (c) 2014 Intel Corporation
   5  *
   6  * Derived from:
   7  *  i2c-diolan-u2c.c
   8  *  Copyright (c) 2010-2011 Ericsson AB
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation, version 2.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/slab.h>
  19 #include <linux/usb.h>
  20 #include <linux/i2c.h>
  21 #include <linux/mutex.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/mfd/core.h>
  24 #include <linux/mfd/dln2.h>
  25 #include <linux/rculist.h>
  26
  27 struct dln2_header {
  28         __le16 size;
  29         __le16 id;
  30         __le16 echo;
  31         __le16 handle;
  32 };
  33
  34 struct dln2_response {
  35         struct dln2_header hdr;
  36         __le16 result;
  37 };
  38
  39 #define DLN2_GENERIC_MODULE_ID          0x00
  40 #define DLN2_GENERIC_CMD(cmd)           DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
  41 #define CMD_GET_DEVICE_VER              DLN2_GENERIC_CMD(0x30)
  42 #define CMD_GET_DEVICE_SN               DLN2_GENERIC_CMD(0x31)
  43
  44 #define DLN2_HW_ID                      0x200
  45 #define DLN2_USB_TIMEOUT                200     /* in ms */
  46 #define DLN2_MAX_RX_SLOTS               16
  47 #define DLN2_MAX_URBS                   16
  48 #define DLN2_RX_BUF_SIZE                512
  49
  50 enum dln2_handle {
  51         DLN2_HANDLE_EVENT = 0,          /* don't change, hardware defined */
  52         DLN2_HANDLE_CTRL,
  53         DLN2_HANDLE_GPIO,
  54         DLN2_HANDLE_I2C,
  55         DLN2_HANDLE_SPI,
  56         DLN2_HANDLES
  57 };
  58
  59 /*
  60  * Receive context used between the receive demultiplexer and the transfer
  61  * routine. While sending a request the transfer routine will look for a free
  62  * receive context and use it to wait for a response and to receive the URB and
  63  * thus the response data.
  64  */
  65 struct dln2_rx_context {
  66         /* completion used to wait for a response */
  67         struct completion done;
  68
  69         /* if non-NULL the URB contains the response */
  70         struct urb *urb;
  71
  72         /* if true then this context is used to wait for a response */
  73         bool in_use;
  74 };
  75
  76 /*
  77  * Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We use the
  78  * handle header field to identify the module in dln2_dev.mod_rx_slots and then
  79  * the echo header field to index the slots field and find the receive context
  80  * for a particular request.
  81  */
  82 struct dln2_mod_rx_slots {
  83         /* RX slots bitmap */
  84         DECLARE_BITMAP(bmap, DLN2_MAX_RX_SLOTS);
  85
  86         /* used to wait for a free RX slot */
  87         wait_queue_head_t wq;
  88
  89         /* used to wait for an RX operation to complete */
  90         struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS];
  91
  92         /* avoid races between alloc/free_rx_slot and dln2_rx_transfer */
  93         spinlock_t lock;
  94 };
  95
  96 struct dln2_dev {
  97         struct usb_device *usb_dev;
  98         struct usb_interface *interface;
  99         u8 ep_in;
 100         u8 ep_out;
 101
 102         struct urb *rx_urb[DLN2_MAX_URBS];
 103         void *rx_buf[DLN2_MAX_URBS];
 104
 105         struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
 106
 107         struct list_head event_cb_list;
 108         spinlock_t event_cb_lock;
 109
 110         bool disconnect;
 111         int active_transfers;
 112         wait_queue_head_t disconnect_wq;
 113         spinlock_t disconnect_lock;
 114 };
 115
 116 struct dln2_event_cb_entry {
 117         struct list_head list;
 118         u16 id;
 119         struct platform_device *pdev;
 120         dln2_event_cb_t callback;
 121 };
 122
 123 int dln2_register_event_cb(struct platform_device *pdev, u16 id,
 124                            dln2_event_cb_t event_cb)
 125 {
 126         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 127         struct dln2_event_cb_entry *i, *entry;
 128         unsigned long flags;
 129         int ret = 0;
 130
 131         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 132         if (!entry)
 133                 return -ENOMEM;
 134
 135         entry->id = id;
 136         entry->callback = event_cb;
 137         entry->pdev = pdev;
 138
 139         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 140
 141         list_for_each_entry(i, &dln2->event_cb_list, list) {
 142                 if (i->id == id) {
 143                         ret = -EBUSY;
 144                         break;
 145                 }
 146         }
 147
 148         if (!ret)
 149                 list_add_rcu(&entry->list, &dln2->event_cb_list);
 150
 151         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 152
 153         if (ret)
 154                 kfree(entry);
 155
 156         return ret;
 157 }
 158 EXPORT_SYMBOL(dln2_register_event_cb);
 159
 160 void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
 161 {
 162         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 163         struct dln2_event_cb_entry *i;
 164         unsigned long flags;
 165         bool found = false;
 166
 167         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 168
 169         list_for_each_entry(i, &dln2->event_cb_list, list) {
 170                 if (i->id == id) {
 171                         list_del_rcu(&i->list);
 172                         found = true;
 173                         break;
 174                 }
 175         }
 176
 177         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 178
 179         if (found) {
 180                 synchronize_rcu();
 181                 kfree(i);
 182         }
 183 }
 184 EXPORT_SYMBOL(dln2_unregister_event_cb);
 185
 186 /*
 187  * Returns true if a valid transfer slot is found. In this case the URB must not
 188  * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
 189  * is woke up. It will be resubmitted there.
 190  */
 191 static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
 192                                    u16 handle, u16 rx_slot)
 193 {
 194         struct device *dev = &dln2->interface->dev;
 195         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 196         struct dln2_rx_context *rxc;
 197         bool valid_slot = false;
 198
 199         if (rx_slot >= DLN2_MAX_RX_SLOTS)
 200                 goto out;
 201
 202         rxc = &rxs->slots[rx_slot];
 203
 204         /*
 205          * No need to disable interrupts as this lock is not taken in interrupt
 206          * context elsewhere in this driver. This function (or its callers) are
 207          * also not exported to other modules.
 208          */
 209         spin_lock(&rxs->lock);
 210         if (rxc->in_use && !rxc->urb) {
 211                 rxc->urb = urb;
 212                 complete(&rxc->done);
 213                 valid_slot = true;
 214         }
 215         spin_unlock(&rxs->lock);
 216
 217 out:
 218         if (!valid_slot)
 219                 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
 220
 221         return valid_slot;
 222 }
 223
 224 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
 225                                      void *data, int len)
 226 {
 227         struct dln2_event_cb_entry *i;
 228
 229         rcu_read_lock();
 230
 231         list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
 232                 if (i->id == id) {
 233                         i->callback(i->pdev, echo, data, len);
 234                         break;
 235                 }
 236         }
 237
 238         rcu_read_unlock();
 239 }
 240
 241 static void dln2_rx(struct urb *urb)
 242 {
 243         struct dln2_dev *dln2 = urb->context;
 244         struct dln2_header *hdr = urb->transfer_buffer;
 245         struct device *dev = &dln2->interface->dev;
 246         u16 id, echo, handle, size;
 247         u8 *data;
 248         int len;
 249         int err;
 250
 251         switch (urb->status) {
 252         case 0:
 253                 /* success */
 254                 break;
 255         case -ECONNRESET:
 256         case -ENOENT:
 257         case -ESHUTDOWN:
 258         case -EPIPE:
 259                 /* this urb is terminated, clean up */
 260                 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
 261                 return;
 262         default:
 263                 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
 264                 goto out;
 265         }
 266
 267         if (urb->actual_length < sizeof(struct dln2_header)) {
 268                 dev_err(dev, "short response: %d\n", urb->actual_length);
 269                 goto out;
 270         }
 271
 272         handle = le16_to_cpu(hdr->handle);
 273         id = le16_to_cpu(hdr->id);
 274         echo = le16_to_cpu(hdr->echo);
 275         size = le16_to_cpu(hdr->size);
 276
 277         if (size != urb->actual_length) {
 278                 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
 279                         handle, id, echo, size, urb->actual_length);
 280                 goto out;
 281         }
 282
 283         if (handle >= DLN2_HANDLES) {
 284                 dev_warn(dev, "invalid handle %d\n", handle);
 285                 goto out;
 286         }
 287
 288         data = urb->transfer_buffer + sizeof(struct dln2_header);
 289         len = urb->actual_length - sizeof(struct dln2_header);
 290
 291         if (handle == DLN2_HANDLE_EVENT) {
 292                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 293         } else {
 294                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 295                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 296                         return;
 297         }
 298
 299 out:
 300         err = usb_submit_urb(urb, GFP_ATOMIC);
 301         if (err < 0)
 302                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 303 }
 304
 305 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 306                            int *obuf_len, gfp_t gfp)
 307 {
 308         int len;
 309         void *buf;
 310         struct dln2_header *hdr;
 311
 312         len = *obuf_len + sizeof(*hdr);
 313         buf = kmalloc(len, gfp);
 314         if (!buf)
 315                 return NULL;
 316
 317         hdr = (struct dln2_header *)buf;
 318         hdr->id = cpu_to_le16(cmd);
 319         hdr->size = cpu_to_le16(len);
 320         hdr->echo = cpu_to_le16(echo);
 321         hdr->handle = cpu_to_le16(handle);
 322
 323         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 324
 325         *obuf_len = len;
 326
 327         return buf;
 328 }
 329
 330 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 331                           const void *obuf, int obuf_len)
 332 {
 333         int ret = 0;
 334         int len = obuf_len;
 335         void *buf;
 336         int actual;
 337
 338         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 339         if (!buf)
 340                 return -ENOMEM;
 341
 342         ret = usb_bulk_msg(dln2->usb_dev,
 343                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 344                            buf, len, &actual, DLN2_USB_TIMEOUT);
 345
 346         kfree(buf);
 347
 348         return ret;
 349 }
 350
 351 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 352 {
 353         struct dln2_mod_rx_slots *rxs;
 354         unsigned long flags;
 355
 356         if (dln2->disconnect) {
 357                 *slot = -ENODEV;
 358                 return true;
 359         }
 360
 361         rxs = &dln2->mod_rx_slots[handle];
 362
 363         spin_lock_irqsave(&rxs->lock, flags);
 364
 365         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 366
 367         if (*slot < DLN2_MAX_RX_SLOTS) {
 368                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 369
 370                 set_bit(*slot, rxs->bmap);
 371                 rxc->in_use = true;
 372         }
 373
 374         spin_unlock_irqrestore(&rxs->lock, flags);
 375
 376         return *slot < DLN2_MAX_RX_SLOTS;
 377 }
 378
 379 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 380 {
 381         int ret;
 382         int slot;
 383
 384         /*
 385          * No need to timeout here, the wait is bounded by the timeout in
 386          * _dln2_transfer.
 387          */
 388         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 389                                        find_free_slot(dln2, handle, &slot));
 390         if (ret < 0)
 391                 return ret;
 392
 393         return slot;
 394 }
 395
 396 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 397 {
 398         struct dln2_mod_rx_slots *rxs;
 399         struct urb *urb = NULL;
 400         unsigned long flags;
 401         struct dln2_rx_context *rxc;
 402
 403         rxs = &dln2->mod_rx_slots[handle];
 404
 405         spin_lock_irqsave(&rxs->lock, flags);
 406
 407         clear_bit(slot, rxs->bmap);
 408
 409         rxc = &rxs->slots[slot];
 410         rxc->in_use = false;
 411         urb = rxc->urb;
 412         rxc->urb = NULL;
 413         reinit_completion(&rxc->done);
 414
 415         spin_unlock_irqrestore(&rxs->lock, flags);
 416
 417         if (urb) {
 418                 int err;
 419                 struct device *dev = &dln2->interface->dev;
 420
 421                 err = usb_submit_urb(urb, GFP_KERNEL);
 422                 if (err < 0)
 423                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 424         }
 425
 426         wake_up_interruptible(&rxs->wq);
 427 }
 428
 429 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 430                           const void *obuf, unsigned obuf_len,
 431                           void *ibuf, unsigned *ibuf_len)
 432 {
 433         int ret = 0;
 434         int rx_slot;
 435         struct dln2_response *rsp;
 436         struct dln2_rx_context *rxc;
 437         struct device *dev = &dln2->interface->dev;
 438         const unsigned long timeout = DLN2_USB_TIMEOUT * HZ / 1000;
 439         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 440         int size;
 441
 442         spin_lock(&dln2->disconnect_lock);
 443         if (!dln2->disconnect)
 444                 dln2->active_transfers++;
 445         else
 446                 ret = -ENODEV;
 447         spin_unlock(&dln2->disconnect_lock);
 448
 449         if (ret)
 450                 return ret;
 451
 452         rx_slot = alloc_rx_slot(dln2, handle);
 453         if (rx_slot < 0) {
 454                 ret = rx_slot;
 455                 goto out_decr;
 456         }
 457
 458         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 459         if (ret < 0) {
 460                 dev_err(dev, "USB write failed: %d\n", ret);
 461                 goto out_free_rx_slot;
 462         }
 463
 464         rxc = &rxs->slots[rx_slot];
 465
 466         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 467         if (ret <= 0) {
 468                 if (!ret)
 469                         ret = -ETIMEDOUT;
 470                 goto out_free_rx_slot;
 471         } else {
 472                 ret = 0;
 473         }
 474
 475         if (dln2->disconnect) {
 476                 ret = -ENODEV;
 477                 goto out_free_rx_slot;
 478         }
 479
 480         /* if we got here we know that the response header has been checked */
 481         rsp = rxc->urb->transfer_buffer;
 482         size = le16_to_cpu(rsp->hdr.size);
 483
 484         if (size < sizeof(*rsp)) {
 485                 ret = -EPROTO;
 486                 goto out_free_rx_slot;
 487         }
 488
 489         if (le16_to_cpu(rsp->result) > 0x80) {
 490                 dev_dbg(dev, "%d received response with error %d\n",
 491                         handle, le16_to_cpu(rsp->result));
 492                 ret = -EREMOTEIO;
 493                 goto out_free_rx_slot;
 494         }
 495
 496         if (!ibuf)
 497                 goto out_free_rx_slot;
 498
 499         if (*ibuf_len > size - sizeof(*rsp))
 500                 *ibuf_len = size - sizeof(*rsp);
 501
 502         memcpy(ibuf, rsp + 1, *ibuf_len);
 503
 504 out_free_rx_slot:
 505         free_rx_slot(dln2, handle, rx_slot);
 506 out_decr:
 507         spin_lock(&dln2->disconnect_lock);
 508         dln2->active_transfers--;
 509         spin_unlock(&dln2->disconnect_lock);
 510         if (dln2->disconnect)
 511                 wake_up(&dln2->disconnect_wq);
 512
 513         return ret;
 514 }
 515
 516 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 517                   const void *obuf, unsigned obuf_len,
 518                   void *ibuf, unsigned *ibuf_len)
 519 {
 520         struct dln2_platform_data *dln2_pdata;
 521         struct dln2_dev *dln2;
 522         u16 handle;
 523
 524         dln2 = dev_get_drvdata(pdev->dev.parent);
 525         dln2_pdata = dev_get_platdata(&pdev->dev);
 526         handle = dln2_pdata->handle;
 527
 528         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 529                               ibuf_len);
 530 }
 531 EXPORT_SYMBOL(dln2_transfer);
 532
 533 static int dln2_check_hw(struct dln2_dev *dln2)
 534 {
 535         int ret;
 536         __le32 hw_type;
 537         int len = sizeof(hw_type);
 538
 539         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 540                              NULL, 0, &hw_type, &len);
 541         if (ret < 0)
 542                 return ret;
 543         if (len < sizeof(hw_type))
 544                 return -EREMOTEIO;
 545
 546         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 547                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 548                         le32_to_cpu(hw_type));
 549                 return -ENODEV;
 550         }
 551
 552         return 0;
 553 }
 554
 555 static int dln2_print_serialno(struct dln2_dev *dln2)
 556 {
 557         int ret;
 558         __le32 serial_no;
 559         int len = sizeof(serial_no);
 560         struct device *dev = &dln2->interface->dev;
 561
 562         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 563                              &serial_no, &len);
 564         if (ret < 0)
 565                 return ret;
 566         if (len < sizeof(serial_no))
 567                 return -EREMOTEIO;
 568
 569         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 570
 571         return 0;
 572 }
 573
 574 static int dln2_hw_init(struct dln2_dev *dln2)
 575 {
 576         int ret;
 577
 578         ret = dln2_check_hw(dln2);
 579         if (ret < 0)
 580                 return ret;
 581
 582         return dln2_print_serialno(dln2);
 583 }
 584
 585 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 586 {
 587         int i;
 588
 589         for (i = 0; i < DLN2_MAX_URBS; i++) {
 590                 usb_kill_urb(dln2->rx_urb[i]);
 591                 usb_free_urb(dln2->rx_urb[i]);
 592                 kfree(dln2->rx_buf[i]);
 593         }
 594 }
 595
 596 static void dln2_free(struct dln2_dev *dln2)
 597 {
 598         dln2_free_rx_urbs(dln2);
 599         usb_put_dev(dln2->usb_dev);
 600         kfree(dln2);
 601 }
 602
 603 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
 604                               struct usb_host_interface *hostif)
 605 {
 606         int i;
 607         int ret;
 608         const int rx_max_size = DLN2_RX_BUF_SIZE;
 609         struct device *dev = &dln2->interface->dev;
 610
 611         for (i = 0; i < DLN2_MAX_URBS; i++) {
 612                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 613                 if (!dln2->rx_buf[i])
 614                         return -ENOMEM;
 615
 616                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 617                 if (!dln2->rx_urb[i])
 618                         return -ENOMEM;
 619
 620                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 621                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 622                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 623
 624                 ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL);
 625                 if (ret < 0) {
 626                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 627                         return ret;
 628                 }
 629         }
 630
 631         return 0;
 632 }
 633
 634 static struct dln2_platform_data dln2_pdata_gpio = {
 635         .handle = DLN2_HANDLE_GPIO,
 636 };
 637
 638 /* Only one I2C port seems to be supported on current hardware */
 639 static struct dln2_platform_data dln2_pdata_i2c = {
 640         .handle = DLN2_HANDLE_I2C,
 641         .port = 0,
 642 };
 643
 644 /* Only one SPI port supported */
 645 static struct dln2_platform_data dln2_pdata_spi = {
 646         .handle = DLN2_HANDLE_SPI,
 647         .port = 0,
 648 };
 649
 650 static const struct mfd_cell dln2_devs[] = {
 651         {
 652                 .name = "dln2-gpio",
 653                 .platform_data = &dln2_pdata_gpio,
 654                 .pdata_size = sizeof(struct dln2_platform_data),
 655         },
 656         {
 657                 .name = "dln2-i2c",
 658                 .platform_data = &dln2_pdata_i2c,
 659                 .pdata_size = sizeof(struct dln2_platform_data),
 660         },
 661         {
 662                 .name = "dln2-spi",
 663                 .platform_data = &dln2_pdata_spi,
 664                 .pdata_size = sizeof(struct dln2_platform_data),
 665         },
 666 };
 667
 668 static void dln2_disconnect(struct usb_interface *interface)
 669 {
 670         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 671         int i, j;
 672
 673         /* don't allow starting new transfers */
 674         spin_lock(&dln2->disconnect_lock);
 675         dln2->disconnect = true;
 676         spin_unlock(&dln2->disconnect_lock);
 677
 678         /* cancel in progress transfers */
 679         for (i = 0; i < DLN2_HANDLES; i++) {
 680                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 681                 unsigned long flags;
 682
 683                 spin_lock_irqsave(&rxs->lock, flags);
 684
 685                 /* cancel all response waiters */
 686                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 687                         struct dln2_rx_context *rxc = &rxs->slots[j];
 688
 689                         if (rxc->in_use)
 690                                 complete(&rxc->done);
 691                 }
 692
 693                 spin_unlock_irqrestore(&rxs->lock, flags);
 694         }
 695
 696         /* wait for transfers to end */
 697         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 698
 699         mfd_remove_devices(&interface->dev);
 700
 701         dln2_free(dln2);
 702 }
 703
 704 static int dln2_probe(struct usb_interface *interface,
 705                       const struct usb_device_id *usb_id)
 706 {
 707         struct usb_host_interface *hostif = interface->cur_altsetting;
 708         struct device *dev = &interface->dev;
 709         struct dln2_dev *dln2;
 710         int ret;
 711         int i, j;
 712
 713         if (hostif->desc.bInterfaceNumber != 0 ||
 714             hostif->desc.bNumEndpoints < 2)
 715                 return -ENODEV;
 716
 717         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 718         if (!dln2)
 719                 return -ENOMEM;
 720
 721         dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
 722         dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
 723         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 724         dln2->interface = interface;
 725         usb_set_intfdata(interface, dln2);
 726         init_waitqueue_head(&dln2->disconnect_wq);
 727
 728         for (i = 0; i < DLN2_HANDLES; i++) {
 729                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 730                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 731                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 732                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 733         }
 734
 735         spin_lock_init(&dln2->event_cb_lock);
 736         spin_lock_init(&dln2->disconnect_lock);
 737         INIT_LIST_HEAD(&dln2->event_cb_list);
 738
 739         ret = dln2_setup_rx_urbs(dln2, hostif);
 740         if (ret)
 741                 goto out_cleanup;
 742
 743         ret = dln2_hw_init(dln2);
 744         if (ret < 0) {
 745                 dev_err(dev, "failed to initialize hardware\n");
 746                 goto out_cleanup;
 747         }
 748
 749         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 750         if (ret != 0) {
 751                 dev_err(dev, "failed to add mfd devices to core\n");
 752                 goto out_cleanup;
 753         }
 754
 755         return 0;
 756
 757 out_cleanup:
 758         dln2_free(dln2);
 759
 760         return ret;
 761 }
 762
 763 static const struct usb_device_id dln2_table[] = {
 764         { USB_DEVICE(0xa257, 0x2013) },
 765         { }
 766 };
 767
 768 MODULE_DEVICE_TABLE(usb, dln2_table);
 769
 770 static struct usb_driver dln2_driver = {
 771         .name = "dln2",
 772         .probe = dln2_probe,
 773         .disconnect = dln2_disconnect,
 774         .id_table = dln2_table,
 775 };
 776
 777 module_usb_driver(dln2_driver);
 778
 779 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 780 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 781 MODULE_LICENSE("GPL v2");