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 enum dln2_endpoint {
  97         DLN2_EP_OUT     = 0,
  98         DLN2_EP_IN      = 1,
  99 };
 100
 101 struct dln2_dev {
 102         struct usb_device *usb_dev;
 103         struct usb_interface *interface;
 104         u8 ep_in;
 105         u8 ep_out;
 106
 107         struct urb *rx_urb[DLN2_MAX_URBS];
 108         void *rx_buf[DLN2_MAX_URBS];
 109
 110         struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
 111
 112         struct list_head event_cb_list;
 113         spinlock_t event_cb_lock;
 114
 115         bool disconnect;
 116         int active_transfers;
 117         wait_queue_head_t disconnect_wq;
 118         spinlock_t disconnect_lock;
 119 };
 120
 121 struct dln2_event_cb_entry {
 122         struct list_head list;
 123         u16 id;
 124         struct platform_device *pdev;
 125         dln2_event_cb_t callback;
 126 };
 127
 128 int dln2_register_event_cb(struct platform_device *pdev, u16 id,
 129                            dln2_event_cb_t event_cb)
 130 {
 131         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 132         struct dln2_event_cb_entry *i, *entry;
 133         unsigned long flags;
 134         int ret = 0;
 135
 136         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 137         if (!entry)
 138                 return -ENOMEM;
 139
 140         entry->id = id;
 141         entry->callback = event_cb;
 142         entry->pdev = pdev;
 143
 144         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 145
 146         list_for_each_entry(i, &dln2->event_cb_list, list) {
 147                 if (i->id == id) {
 148                         ret = -EBUSY;
 149                         break;
 150                 }
 151         }
 152
 153         if (!ret)
 154                 list_add_rcu(&entry->list, &dln2->event_cb_list);
 155
 156         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 157
 158         if (ret)
 159                 kfree(entry);
 160
 161         return ret;
 162 }
 163 EXPORT_SYMBOL(dln2_register_event_cb);
 164
 165 void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
 166 {
 167         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 168         struct dln2_event_cb_entry *i;
 169         unsigned long flags;
 170         bool found = false;
 171
 172         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 173
 174         list_for_each_entry(i, &dln2->event_cb_list, list) {
 175                 if (i->id == id) {
 176                         list_del_rcu(&i->list);
 177                         found = true;
 178                         break;
 179                 }
 180         }
 181
 182         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 183
 184         if (found) {
 185                 synchronize_rcu();
 186                 kfree(i);
 187         }
 188 }
 189 EXPORT_SYMBOL(dln2_unregister_event_cb);
 190
 191 /*
 192  * Returns true if a valid transfer slot is found. In this case the URB must not
 193  * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
 194  * is woke up. It will be resubmitted there.
 195  */
 196 static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
 197                                    u16 handle, u16 rx_slot)
 198 {
 199         struct device *dev = &dln2->interface->dev;
 200         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 201         struct dln2_rx_context *rxc;
 202         unsigned long flags;
 203         bool valid_slot = false;
 204
 205         if (rx_slot >= DLN2_MAX_RX_SLOTS)
 206                 goto out;
 207
 208         rxc = &rxs->slots[rx_slot];
 209
 210         spin_lock_irqsave(&rxs->lock, flags);
 211         if (rxc->in_use && !rxc->urb) {
 212                 rxc->urb = urb;
 213                 complete(&rxc->done);
 214                 valid_slot = true;
 215         }
 216         spin_unlock_irqrestore(&rxs->lock, flags);
 217
 218 out:
 219         if (!valid_slot)
 220                 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
 221
 222         return valid_slot;
 223 }
 224
 225 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
 226                                      void *data, int len)
 227 {
 228         struct dln2_event_cb_entry *i;
 229
 230         rcu_read_lock();
 231
 232         list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
 233                 if (i->id == id) {
 234                         i->callback(i->pdev, echo, data, len);
 235                         break;
 236                 }
 237         }
 238
 239         rcu_read_unlock();
 240 }
 241
 242 static void dln2_rx(struct urb *urb)
 243 {
 244         struct dln2_dev *dln2 = urb->context;
 245         struct dln2_header *hdr = urb->transfer_buffer;
 246         struct device *dev = &dln2->interface->dev;
 247         u16 id, echo, handle, size;
 248         u8 *data;
 249         int len;
 250         int err;
 251
 252         switch (urb->status) {
 253         case 0:
 254                 /* success */
 255                 break;
 256         case -ECONNRESET:
 257         case -ENOENT:
 258         case -ESHUTDOWN:
 259         case -EPIPE:
 260                 /* this urb is terminated, clean up */
 261                 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
 262                 return;
 263         default:
 264                 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
 265                 goto out;
 266         }
 267
 268         if (urb->actual_length < sizeof(struct dln2_header)) {
 269                 dev_err(dev, "short response: %d\n", urb->actual_length);
 270                 goto out;
 271         }
 272
 273         handle = le16_to_cpu(hdr->handle);
 274         id = le16_to_cpu(hdr->id);
 275         echo = le16_to_cpu(hdr->echo);
 276         size = le16_to_cpu(hdr->size);
 277
 278         if (size != urb->actual_length) {
 279                 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
 280                         handle, id, echo, size, urb->actual_length);
 281                 goto out;
 282         }
 283
 284         if (handle >= DLN2_HANDLES) {
 285                 dev_warn(dev, "invalid handle %d\n", handle);
 286                 goto out;
 287         }
 288
 289         data = urb->transfer_buffer + sizeof(struct dln2_header);
 290         len = urb->actual_length - sizeof(struct dln2_header);
 291
 292         if (handle == DLN2_HANDLE_EVENT) {
 293                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 294         } else {
 295                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 296                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 297                         return;
 298         }
 299
 300 out:
 301         err = usb_submit_urb(urb, GFP_ATOMIC);
 302         if (err < 0)
 303                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 304 }
 305
 306 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 307                            int *obuf_len, gfp_t gfp)
 308 {
 309         int len;
 310         void *buf;
 311         struct dln2_header *hdr;
 312
 313         len = *obuf_len + sizeof(*hdr);
 314         buf = kmalloc(len, gfp);
 315         if (!buf)
 316                 return NULL;
 317
 318         hdr = (struct dln2_header *)buf;
 319         hdr->id = cpu_to_le16(cmd);
 320         hdr->size = cpu_to_le16(len);
 321         hdr->echo = cpu_to_le16(echo);
 322         hdr->handle = cpu_to_le16(handle);
 323
 324         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 325
 326         *obuf_len = len;
 327
 328         return buf;
 329 }
 330
 331 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 332                           const void *obuf, int obuf_len)
 333 {
 334         int ret = 0;
 335         int len = obuf_len;
 336         void *buf;
 337         int actual;
 338
 339         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 340         if (!buf)
 341                 return -ENOMEM;
 342
 343         ret = usb_bulk_msg(dln2->usb_dev,
 344                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 345                            buf, len, &actual, DLN2_USB_TIMEOUT);
 346
 347         kfree(buf);
 348
 349         return ret;
 350 }
 351
 352 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 353 {
 354         struct dln2_mod_rx_slots *rxs;
 355         unsigned long flags;
 356
 357         if (dln2->disconnect) {
 358                 *slot = -ENODEV;
 359                 return true;
 360         }
 361
 362         rxs = &dln2->mod_rx_slots[handle];
 363
 364         spin_lock_irqsave(&rxs->lock, flags);
 365
 366         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 367
 368         if (*slot < DLN2_MAX_RX_SLOTS) {
 369                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 370
 371                 set_bit(*slot, rxs->bmap);
 372                 rxc->in_use = true;
 373         }
 374
 375         spin_unlock_irqrestore(&rxs->lock, flags);
 376
 377         return *slot < DLN2_MAX_RX_SLOTS;
 378 }
 379
 380 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 381 {
 382         int ret;
 383         int slot;
 384
 385         /*
 386          * No need to timeout here, the wait is bounded by the timeout in
 387          * _dln2_transfer.
 388          */
 389         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 390                                        find_free_slot(dln2, handle, &slot));
 391         if (ret < 0)
 392                 return ret;
 393
 394         return slot;
 395 }
 396
 397 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 398 {
 399         struct dln2_mod_rx_slots *rxs;
 400         struct urb *urb = NULL;
 401         unsigned long flags;
 402         struct dln2_rx_context *rxc;
 403
 404         rxs = &dln2->mod_rx_slots[handle];
 405
 406         spin_lock_irqsave(&rxs->lock, flags);
 407
 408         clear_bit(slot, rxs->bmap);
 409
 410         rxc = &rxs->slots[slot];
 411         rxc->in_use = false;
 412         urb = rxc->urb;
 413         rxc->urb = NULL;
 414         reinit_completion(&rxc->done);
 415
 416         spin_unlock_irqrestore(&rxs->lock, flags);
 417
 418         if (urb) {
 419                 int err;
 420                 struct device *dev = &dln2->interface->dev;
 421
 422                 err = usb_submit_urb(urb, GFP_KERNEL);
 423                 if (err < 0)
 424                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 425         }
 426
 427         wake_up_interruptible(&rxs->wq);
 428 }
 429
 430 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 431                           const void *obuf, unsigned obuf_len,
 432                           void *ibuf, unsigned *ibuf_len)
 433 {
 434         int ret = 0;
 435         int rx_slot;
 436         struct dln2_response *rsp;
 437         struct dln2_rx_context *rxc;
 438         struct device *dev = &dln2->interface->dev;
 439         const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
 440         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 441         int size;
 442
 443         spin_lock(&dln2->disconnect_lock);
 444         if (!dln2->disconnect)
 445                 dln2->active_transfers++;
 446         else
 447                 ret = -ENODEV;
 448         spin_unlock(&dln2->disconnect_lock);
 449
 450         if (ret)
 451                 return ret;
 452
 453         rx_slot = alloc_rx_slot(dln2, handle);
 454         if (rx_slot < 0) {
 455                 ret = rx_slot;
 456                 goto out_decr;
 457         }
 458
 459         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 460         if (ret < 0) {
 461                 dev_err(dev, "USB write failed: %d\n", ret);
 462                 goto out_free_rx_slot;
 463         }
 464
 465         rxc = &rxs->slots[rx_slot];
 466
 467         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 468         if (ret <= 0) {
 469                 if (!ret)
 470                         ret = -ETIMEDOUT;
 471                 goto out_free_rx_slot;
 472         } else {
 473                 ret = 0;
 474         }
 475
 476         if (dln2->disconnect) {
 477                 ret = -ENODEV;
 478                 goto out_free_rx_slot;
 479         }
 480
 481         /* if we got here we know that the response header has been checked */
 482         rsp = rxc->urb->transfer_buffer;
 483         size = le16_to_cpu(rsp->hdr.size);
 484
 485         if (size < sizeof(*rsp)) {
 486                 ret = -EPROTO;
 487                 goto out_free_rx_slot;
 488         }
 489
 490         if (le16_to_cpu(rsp->result) > 0x80) {
 491                 dev_dbg(dev, "%d received response with error %d\n",
 492                         handle, le16_to_cpu(rsp->result));
 493                 ret = -EREMOTEIO;
 494                 goto out_free_rx_slot;
 495         }
 496
 497         if (!ibuf)
 498                 goto out_free_rx_slot;
 499
 500         if (*ibuf_len > size - sizeof(*rsp))
 501                 *ibuf_len = size - sizeof(*rsp);
 502
 503         memcpy(ibuf, rsp + 1, *ibuf_len);
 504
 505 out_free_rx_slot:
 506         free_rx_slot(dln2, handle, rx_slot);
 507 out_decr:
 508         spin_lock(&dln2->disconnect_lock);
 509         dln2->active_transfers--;
 510         spin_unlock(&dln2->disconnect_lock);
 511         if (dln2->disconnect)
 512                 wake_up(&dln2->disconnect_wq);
 513
 514         return ret;
 515 }
 516
 517 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 518                   const void *obuf, unsigned obuf_len,
 519                   void *ibuf, unsigned *ibuf_len)
 520 {
 521         struct dln2_platform_data *dln2_pdata;
 522         struct dln2_dev *dln2;
 523         u16 handle;
 524
 525         dln2 = dev_get_drvdata(pdev->dev.parent);
 526         dln2_pdata = dev_get_platdata(&pdev->dev);
 527         handle = dln2_pdata->handle;
 528
 529         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 530                               ibuf_len);
 531 }
 532 EXPORT_SYMBOL(dln2_transfer);
 533
 534 static int dln2_check_hw(struct dln2_dev *dln2)
 535 {
 536         int ret;
 537         __le32 hw_type;
 538         int len = sizeof(hw_type);
 539
 540         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 541                              NULL, 0, &hw_type, &len);
 542         if (ret < 0)
 543                 return ret;
 544         if (len < sizeof(hw_type))
 545                 return -EREMOTEIO;
 546
 547         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 548                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 549                         le32_to_cpu(hw_type));
 550                 return -ENODEV;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static int dln2_print_serialno(struct dln2_dev *dln2)
 557 {
 558         int ret;
 559         __le32 serial_no;
 560         int len = sizeof(serial_no);
 561         struct device *dev = &dln2->interface->dev;
 562
 563         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 564                              &serial_no, &len);
 565         if (ret < 0)
 566                 return ret;
 567         if (len < sizeof(serial_no))
 568                 return -EREMOTEIO;
 569
 570         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 571
 572         return 0;
 573 }
 574
 575 static int dln2_hw_init(struct dln2_dev *dln2)
 576 {
 577         int ret;
 578
 579         ret = dln2_check_hw(dln2);
 580         if (ret < 0)
 581                 return ret;
 582
 583         return dln2_print_serialno(dln2);
 584 }
 585
 586 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 587 {
 588         int i;
 589
 590         for (i = 0; i < DLN2_MAX_URBS; i++) {
 591                 usb_free_urb(dln2->rx_urb[i]);
 592                 kfree(dln2->rx_buf[i]);
 593         }
 594 }
 595
 596 static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
 597 {
 598         int i;
 599
 600         for (i = 0; i < DLN2_MAX_URBS; i++)
 601                 usb_kill_urb(dln2->rx_urb[i]);
 602 }
 603
 604 static void dln2_free(struct dln2_dev *dln2)
 605 {
 606         dln2_free_rx_urbs(dln2);
 607         usb_put_dev(dln2->usb_dev);
 608         kfree(dln2);
 609 }
 610
 611 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
 612                               struct usb_host_interface *hostif)
 613 {
 614         int i;
 615         const int rx_max_size = DLN2_RX_BUF_SIZE;
 616
 617         for (i = 0; i < DLN2_MAX_URBS; i++) {
 618                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 619                 if (!dln2->rx_buf[i])
 620                         return -ENOMEM;
 621
 622                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 623                 if (!dln2->rx_urb[i])
 624                         return -ENOMEM;
 625
 626                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 627                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 628                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 629         }
 630
 631         return 0;
 632 }
 633
 634 static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
 635 {
 636         struct device *dev = &dln2->interface->dev;
 637         int ret;
 638         int i;
 639
 640         for (i = 0; i < DLN2_MAX_URBS; i++) {
 641                 ret = usb_submit_urb(dln2->rx_urb[i], gfp);
 642                 if (ret < 0) {
 643                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 644                         return ret;
 645                 }
 646         }
 647
 648         return 0;
 649 }
 650
 651 static struct dln2_platform_data dln2_pdata_gpio = {
 652         .handle = DLN2_HANDLE_GPIO,
 653 };
 654
 655 /* Only one I2C port seems to be supported on current hardware */
 656 static struct dln2_platform_data dln2_pdata_i2c = {
 657         .handle = DLN2_HANDLE_I2C,
 658         .port = 0,
 659 };
 660
 661 /* Only one SPI port supported */
 662 static struct dln2_platform_data dln2_pdata_spi = {
 663         .handle = DLN2_HANDLE_SPI,
 664         .port = 0,
 665 };
 666
 667 static const struct mfd_cell dln2_devs[] = {
 668         {
 669                 .name = "dln2-gpio",
 670                 .platform_data = &dln2_pdata_gpio,
 671                 .pdata_size = sizeof(struct dln2_platform_data),
 672         },
 673         {
 674                 .name = "dln2-i2c",
 675                 .platform_data = &dln2_pdata_i2c,
 676                 .pdata_size = sizeof(struct dln2_platform_data),
 677         },
 678         {
 679                 .name = "dln2-spi",
 680                 .platform_data = &dln2_pdata_spi,
 681                 .pdata_size = sizeof(struct dln2_platform_data),
 682         },
 683 };
 684
 685 static void dln2_stop(struct dln2_dev *dln2)
 686 {
 687         int i, j;
 688
 689         /* don't allow starting new transfers */
 690         spin_lock(&dln2->disconnect_lock);
 691         dln2->disconnect = true;
 692         spin_unlock(&dln2->disconnect_lock);
 693
 694         /* cancel in progress transfers */
 695         for (i = 0; i < DLN2_HANDLES; i++) {
 696                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 697                 unsigned long flags;
 698
 699                 spin_lock_irqsave(&rxs->lock, flags);
 700
 701                 /* cancel all response waiters */
 702                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 703                         struct dln2_rx_context *rxc = &rxs->slots[j];
 704
 705                         if (rxc->in_use)
 706                                 complete(&rxc->done);
 707                 }
 708
 709                 spin_unlock_irqrestore(&rxs->lock, flags);
 710         }
 711
 712         /* wait for transfers to end */
 713         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 714
 715         dln2_stop_rx_urbs(dln2);
 716 }
 717
 718 static void dln2_disconnect(struct usb_interface *interface)
 719 {
 720         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 721
 722         dln2_stop(dln2);
 723
 724         mfd_remove_devices(&interface->dev);
 725
 726         dln2_free(dln2);
 727 }
 728
 729 static int dln2_probe(struct usb_interface *interface,
 730                       const struct usb_device_id *usb_id)
 731 {
 732         struct usb_host_interface *hostif = interface->cur_altsetting;
 733         struct usb_endpoint_descriptor *epin;
 734         struct usb_endpoint_descriptor *epout;
 735         struct device *dev = &interface->dev;
 736         struct dln2_dev *dln2;
 737         int ret;
 738         int i, j;
 739
 740         if (hostif->desc.bInterfaceNumber != 0 ||
 741             hostif->desc.bNumEndpoints < 2)
 742                 return -ENODEV;
 743
 744         epout = &hostif->endpoint[DLN2_EP_OUT].desc;
 745         if (!usb_endpoint_is_bulk_out(epout))
 746                 return -ENODEV;
 747         epin = &hostif->endpoint[DLN2_EP_IN].desc;
 748         if (!usb_endpoint_is_bulk_in(epin))
 749                 return -ENODEV;
 750
 751         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 752         if (!dln2)
 753                 return -ENOMEM;
 754
 755         dln2->ep_out = epout->bEndpointAddress;
 756         dln2->ep_in = epin->bEndpointAddress;
 757         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 758         dln2->interface = interface;
 759         usb_set_intfdata(interface, dln2);
 760         init_waitqueue_head(&dln2->disconnect_wq);
 761
 762         for (i = 0; i < DLN2_HANDLES; i++) {
 763                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 764                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 765                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 766                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 767         }
 768
 769         spin_lock_init(&dln2->event_cb_lock);
 770         spin_lock_init(&dln2->disconnect_lock);
 771         INIT_LIST_HEAD(&dln2->event_cb_list);
 772
 773         ret = dln2_setup_rx_urbs(dln2, hostif);
 774         if (ret)
 775                 goto out_free;
 776
 777         ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
 778         if (ret)
 779                 goto out_stop_rx;
 780
 781         ret = dln2_hw_init(dln2);
 782         if (ret < 0) {
 783                 dev_err(dev, "failed to initialize hardware\n");
 784                 goto out_stop_rx;
 785         }
 786
 787         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 788         if (ret != 0) {
 789                 dev_err(dev, "failed to add mfd devices to core\n");
 790                 goto out_stop_rx;
 791         }
 792
 793         return 0;
 794
 795 out_stop_rx:
 796         dln2_stop_rx_urbs(dln2);
 797
 798 out_free:
 799         dln2_free(dln2);
 800
 801         return ret;
 802 }
 803
 804 static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
 805 {
 806         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 807
 808         dln2_stop(dln2);
 809
 810         return 0;
 811 }
 812
 813 static int dln2_resume(struct usb_interface *iface)
 814 {
 815         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 816
 817         dln2->disconnect = false;
 818
 819         return dln2_start_rx_urbs(dln2, GFP_NOIO);
 820 }
 821
 822 static const struct usb_device_id dln2_table[] = {
 823         { USB_DEVICE(0xa257, 0x2013) },
 824         { }
 825 };
 826
 827 MODULE_DEVICE_TABLE(usb, dln2_table);
 828
 829 static struct usb_driver dln2_driver = {
 830         .name = "dln2",
 831         .probe = dln2_probe,
 832         .disconnect = dln2_disconnect,
 833         .id_table = dln2_table,
 834         .suspend = dln2_suspend,
 835         .resume = dln2_resume,
 836 };
 837
 838 module_usb_driver(dln2_driver);
 839
 840 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 841 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 842 MODULE_LICENSE("GPL v2");