drivers/mfd/dln2.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for the Diolan DLN-2 USB adapter
   4  *
   5  * Copyright (c) 2014 Intel Corporation
   6  *
   7  * Derived from:
   8  *  i2c-diolan-u2c.c
   9  *  Copyright (c) 2010-2011 Ericsson AB
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/slab.h>
  16 #include <linux/usb.h>
  17 #include <linux/i2c.h>
  18 #include <linux/mutex.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/mfd/core.h>
  21 #include <linux/mfd/dln2.h>
  22 #include <linux/rculist.h>
  23
  24 struct dln2_header {
  25         __le16 size;
  26         __le16 id;
  27         __le16 echo;
  28         __le16 handle;
  29 };
  30
  31 struct dln2_response {
  32         struct dln2_header hdr;
  33         __le16 result;
  34 };
  35
  36 #define DLN2_GENERIC_MODULE_ID          0x00
  37 #define DLN2_GENERIC_CMD(cmd)           DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
  38 #define CMD_GET_DEVICE_VER              DLN2_GENERIC_CMD(0x30)
  39 #define CMD_GET_DEVICE_SN               DLN2_GENERIC_CMD(0x31)
  40
  41 #define DLN2_HW_ID                      0x200
  42 #define DLN2_USB_TIMEOUT                200     /* in ms */
  43 #define DLN2_MAX_RX_SLOTS               16
  44 #define DLN2_MAX_URBS                   16
  45 #define DLN2_RX_BUF_SIZE                512
  46
  47 enum dln2_handle {
  48         DLN2_HANDLE_EVENT = 0,          /* don't change, hardware defined */
  49         DLN2_HANDLE_CTRL,
  50         DLN2_HANDLE_GPIO,
  51         DLN2_HANDLE_I2C,
  52         DLN2_HANDLE_SPI,
  53         DLN2_HANDLES
  54 };
  55
  56 /*
  57  * Receive context used between the receive demultiplexer and the transfer
  58  * routine. While sending a request the transfer routine will look for a free
  59  * receive context and use it to wait for a response and to receive the URB and
  60  * thus the response data.
  61  */
  62 struct dln2_rx_context {
  63         /* completion used to wait for a response */
  64         struct completion done;
  65
  66         /* if non-NULL the URB contains the response */
  67         struct urb *urb;
  68
  69         /* if true then this context is used to wait for a response */
  70         bool in_use;
  71 };
  72
  73 /*
  74  * Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We use the
  75  * handle header field to identify the module in dln2_dev.mod_rx_slots and then
  76  * the echo header field to index the slots field and find the receive context
  77  * for a particular request.
  78  */
  79 struct dln2_mod_rx_slots {
  80         /* RX slots bitmap */
  81         DECLARE_BITMAP(bmap, DLN2_MAX_RX_SLOTS);
  82
  83         /* used to wait for a free RX slot */
  84         wait_queue_head_t wq;
  85
  86         /* used to wait for an RX operation to complete */
  87         struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS];
  88
  89         /* avoid races between alloc/free_rx_slot and dln2_rx_transfer */
  90         spinlock_t lock;
  91 };
  92
  93 struct dln2_dev {
  94         struct usb_device *usb_dev;
  95         struct usb_interface *interface;
  96         u8 ep_in;
  97         u8 ep_out;
  98
  99         struct urb *rx_urb[DLN2_MAX_URBS];
 100         void *rx_buf[DLN2_MAX_URBS];
 101
 102         struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
 103
 104         struct list_head event_cb_list;
 105         spinlock_t event_cb_lock;
 106
 107         bool disconnect;
 108         int active_transfers;
 109         wait_queue_head_t disconnect_wq;
 110         spinlock_t disconnect_lock;
 111 };
 112
 113 struct dln2_event_cb_entry {
 114         struct list_head list;
 115         u16 id;
 116         struct platform_device *pdev;
 117         dln2_event_cb_t callback;
 118 };
 119
 120 int dln2_register_event_cb(struct platform_device *pdev, u16 id,
 121                            dln2_event_cb_t event_cb)
 122 {
 123         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 124         struct dln2_event_cb_entry *i, *entry;
 125         unsigned long flags;
 126         int ret = 0;
 127
 128         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 129         if (!entry)
 130                 return -ENOMEM;
 131
 132         entry->id = id;
 133         entry->callback = event_cb;
 134         entry->pdev = pdev;
 135
 136         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 137
 138         list_for_each_entry(i, &dln2->event_cb_list, list) {
 139                 if (i->id == id) {
 140                         ret = -EBUSY;
 141                         break;
 142                 }
 143         }
 144
 145         if (!ret)
 146                 list_add_rcu(&entry->list, &dln2->event_cb_list);
 147
 148         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 149
 150         if (ret)
 151                 kfree(entry);
 152
 153         return ret;
 154 }
 155 EXPORT_SYMBOL(dln2_register_event_cb);
 156
 157 void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
 158 {
 159         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 160         struct dln2_event_cb_entry *i;
 161         unsigned long flags;
 162         bool found = false;
 163
 164         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 165
 166         list_for_each_entry(i, &dln2->event_cb_list, list) {
 167                 if (i->id == id) {
 168                         list_del_rcu(&i->list);
 169                         found = true;
 170                         break;
 171                 }
 172         }
 173
 174         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 175
 176         if (found) {
 177                 synchronize_rcu();
 178                 kfree(i);
 179         }
 180 }
 181 EXPORT_SYMBOL(dln2_unregister_event_cb);
 182
 183 /*
 184  * Returns true if a valid transfer slot is found. In this case the URB must not
 185  * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
 186  * is woke up. It will be resubmitted there.
 187  */
 188 static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
 189                                    u16 handle, u16 rx_slot)
 190 {
 191         struct device *dev = &dln2->interface->dev;
 192         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 193         struct dln2_rx_context *rxc;
 194         unsigned long flags;
 195         bool valid_slot = false;
 196
 197         if (rx_slot >= DLN2_MAX_RX_SLOTS)
 198                 goto out;
 199
 200         rxc = &rxs->slots[rx_slot];
 201
 202         spin_lock_irqsave(&rxs->lock, flags);
 203         if (rxc->in_use && !rxc->urb) {
 204                 rxc->urb = urb;
 205                 complete(&rxc->done);
 206                 valid_slot = true;
 207         }
 208         spin_unlock_irqrestore(&rxs->lock, flags);
 209
 210 out:
 211         if (!valid_slot)
 212                 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
 213
 214         return valid_slot;
 215 }
 216
 217 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
 218                                      void *data, int len)
 219 {
 220         struct dln2_event_cb_entry *i;
 221
 222         rcu_read_lock();
 223
 224         list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
 225                 if (i->id == id) {
 226                         i->callback(i->pdev, echo, data, len);
 227                         break;
 228                 }
 229         }
 230
 231         rcu_read_unlock();
 232 }
 233
 234 static void dln2_rx(struct urb *urb)
 235 {
 236         struct dln2_dev *dln2 = urb->context;
 237         struct dln2_header *hdr = urb->transfer_buffer;
 238         struct device *dev = &dln2->interface->dev;
 239         u16 id, echo, handle, size;
 240         u8 *data;
 241         int len;
 242         int err;
 243
 244         switch (urb->status) {
 245         case 0:
 246                 /* success */
 247                 break;
 248         case -ECONNRESET:
 249         case -ENOENT:
 250         case -ESHUTDOWN:
 251         case -EPIPE:
 252                 /* this urb is terminated, clean up */
 253                 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
 254                 return;
 255         default:
 256                 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
 257                 goto out;
 258         }
 259
 260         if (urb->actual_length < sizeof(struct dln2_header)) {
 261                 dev_err(dev, "short response: %d\n", urb->actual_length);
 262                 goto out;
 263         }
 264
 265         handle = le16_to_cpu(hdr->handle);
 266         id = le16_to_cpu(hdr->id);
 267         echo = le16_to_cpu(hdr->echo);
 268         size = le16_to_cpu(hdr->size);
 269
 270         if (size != urb->actual_length) {
 271                 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
 272                         handle, id, echo, size, urb->actual_length);
 273                 goto out;
 274         }
 275
 276         if (handle >= DLN2_HANDLES) {
 277                 dev_warn(dev, "invalid handle %d\n", handle);
 278                 goto out;
 279         }
 280
 281         data = urb->transfer_buffer + sizeof(struct dln2_header);
 282         len = urb->actual_length - sizeof(struct dln2_header);
 283
 284         if (handle == DLN2_HANDLE_EVENT) {
 285                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 286         } else {
 287                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 288                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 289                         return;
 290         }
 291
 292 out:
 293         err = usb_submit_urb(urb, GFP_ATOMIC);
 294         if (err < 0)
 295                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 296 }
 297
 298 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 299                            int *obuf_len, gfp_t gfp)
 300 {
 301         int len;
 302         void *buf;
 303         struct dln2_header *hdr;
 304
 305         len = *obuf_len + sizeof(*hdr);
 306         buf = kmalloc(len, gfp);
 307         if (!buf)
 308                 return NULL;
 309
 310         hdr = (struct dln2_header *)buf;
 311         hdr->id = cpu_to_le16(cmd);
 312         hdr->size = cpu_to_le16(len);
 313         hdr->echo = cpu_to_le16(echo);
 314         hdr->handle = cpu_to_le16(handle);
 315
 316         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 317
 318         *obuf_len = len;
 319
 320         return buf;
 321 }
 322
 323 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 324                           const void *obuf, int obuf_len)
 325 {
 326         int ret = 0;
 327         int len = obuf_len;
 328         void *buf;
 329         int actual;
 330
 331         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 332         if (!buf)
 333                 return -ENOMEM;
 334
 335         ret = usb_bulk_msg(dln2->usb_dev,
 336                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 337                            buf, len, &actual, DLN2_USB_TIMEOUT);
 338
 339         kfree(buf);
 340
 341         return ret;
 342 }
 343
 344 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 345 {
 346         struct dln2_mod_rx_slots *rxs;
 347         unsigned long flags;
 348
 349         if (dln2->disconnect) {
 350                 *slot = -ENODEV;
 351                 return true;
 352         }
 353
 354         rxs = &dln2->mod_rx_slots[handle];
 355
 356         spin_lock_irqsave(&rxs->lock, flags);
 357
 358         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 359
 360         if (*slot < DLN2_MAX_RX_SLOTS) {
 361                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 362
 363                 set_bit(*slot, rxs->bmap);
 364                 rxc->in_use = true;
 365         }
 366
 367         spin_unlock_irqrestore(&rxs->lock, flags);
 368
 369         return *slot < DLN2_MAX_RX_SLOTS;
 370 }
 371
 372 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 373 {
 374         int ret;
 375         int slot;
 376
 377         /*
 378          * No need to timeout here, the wait is bounded by the timeout in
 379          * _dln2_transfer.
 380          */
 381         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 382                                        find_free_slot(dln2, handle, &slot));
 383         if (ret < 0)
 384                 return ret;
 385
 386         return slot;
 387 }
 388
 389 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 390 {
 391         struct dln2_mod_rx_slots *rxs;
 392         struct urb *urb = NULL;
 393         unsigned long flags;
 394         struct dln2_rx_context *rxc;
 395
 396         rxs = &dln2->mod_rx_slots[handle];
 397
 398         spin_lock_irqsave(&rxs->lock, flags);
 399
 400         clear_bit(slot, rxs->bmap);
 401
 402         rxc = &rxs->slots[slot];
 403         rxc->in_use = false;
 404         urb = rxc->urb;
 405         rxc->urb = NULL;
 406         reinit_completion(&rxc->done);
 407
 408         spin_unlock_irqrestore(&rxs->lock, flags);
 409
 410         if (urb) {
 411                 int err;
 412                 struct device *dev = &dln2->interface->dev;
 413
 414                 err = usb_submit_urb(urb, GFP_KERNEL);
 415                 if (err < 0)
 416                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 417         }
 418
 419         wake_up_interruptible(&rxs->wq);
 420 }
 421
 422 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 423                           const void *obuf, unsigned obuf_len,
 424                           void *ibuf, unsigned *ibuf_len)
 425 {
 426         int ret = 0;
 427         int rx_slot;
 428         struct dln2_response *rsp;
 429         struct dln2_rx_context *rxc;
 430         struct device *dev = &dln2->interface->dev;
 431         const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
 432         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 433         int size;
 434
 435         spin_lock(&dln2->disconnect_lock);
 436         if (!dln2->disconnect)
 437                 dln2->active_transfers++;
 438         else
 439                 ret = -ENODEV;
 440         spin_unlock(&dln2->disconnect_lock);
 441
 442         if (ret)
 443                 return ret;
 444
 445         rx_slot = alloc_rx_slot(dln2, handle);
 446         if (rx_slot < 0) {
 447                 ret = rx_slot;
 448                 goto out_decr;
 449         }
 450
 451         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 452         if (ret < 0) {
 453                 dev_err(dev, "USB write failed: %d\n", ret);
 454                 goto out_free_rx_slot;
 455         }
 456
 457         rxc = &rxs->slots[rx_slot];
 458
 459         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 460         if (ret <= 0) {
 461                 if (!ret)
 462                         ret = -ETIMEDOUT;
 463                 goto out_free_rx_slot;
 464         } else {
 465                 ret = 0;
 466         }
 467
 468         if (dln2->disconnect) {
 469                 ret = -ENODEV;
 470                 goto out_free_rx_slot;
 471         }
 472
 473         /* if we got here we know that the response header has been checked */
 474         rsp = rxc->urb->transfer_buffer;
 475         size = le16_to_cpu(rsp->hdr.size);
 476
 477         if (size < sizeof(*rsp)) {
 478                 ret = -EPROTO;
 479                 goto out_free_rx_slot;
 480         }
 481
 482         if (le16_to_cpu(rsp->result) > 0x80) {
 483                 dev_dbg(dev, "%d received response with error %d\n",
 484                         handle, le16_to_cpu(rsp->result));
 485                 ret = -EREMOTEIO;
 486                 goto out_free_rx_slot;
 487         }
 488
 489         if (!ibuf)
 490                 goto out_free_rx_slot;
 491
 492         if (*ibuf_len > size - sizeof(*rsp))
 493                 *ibuf_len = size - sizeof(*rsp);
 494
 495         memcpy(ibuf, rsp + 1, *ibuf_len);
 496
 497 out_free_rx_slot:
 498         free_rx_slot(dln2, handle, rx_slot);
 499 out_decr:
 500         spin_lock(&dln2->disconnect_lock);
 501         dln2->active_transfers--;
 502         spin_unlock(&dln2->disconnect_lock);
 503         if (dln2->disconnect)
 504                 wake_up(&dln2->disconnect_wq);
 505
 506         return ret;
 507 }
 508
 509 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 510                   const void *obuf, unsigned obuf_len,
 511                   void *ibuf, unsigned *ibuf_len)
 512 {
 513         struct dln2_platform_data *dln2_pdata;
 514         struct dln2_dev *dln2;
 515         u16 handle;
 516
 517         dln2 = dev_get_drvdata(pdev->dev.parent);
 518         dln2_pdata = dev_get_platdata(&pdev->dev);
 519         handle = dln2_pdata->handle;
 520
 521         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 522                               ibuf_len);
 523 }
 524 EXPORT_SYMBOL(dln2_transfer);
 525
 526 static int dln2_check_hw(struct dln2_dev *dln2)
 527 {
 528         int ret;
 529         __le32 hw_type;
 530         int len = sizeof(hw_type);
 531
 532         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 533                              NULL, 0, &hw_type, &len);
 534         if (ret < 0)
 535                 return ret;
 536         if (len < sizeof(hw_type))
 537                 return -EREMOTEIO;
 538
 539         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 540                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 541                         le32_to_cpu(hw_type));
 542                 return -ENODEV;
 543         }
 544
 545         return 0;
 546 }
 547
 548 static int dln2_print_serialno(struct dln2_dev *dln2)
 549 {
 550         int ret;
 551         __le32 serial_no;
 552         int len = sizeof(serial_no);
 553         struct device *dev = &dln2->interface->dev;
 554
 555         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 556                              &serial_no, &len);
 557         if (ret < 0)
 558                 return ret;
 559         if (len < sizeof(serial_no))
 560                 return -EREMOTEIO;
 561
 562         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 563
 564         return 0;
 565 }
 566
 567 static int dln2_hw_init(struct dln2_dev *dln2)
 568 {
 569         int ret;
 570
 571         ret = dln2_check_hw(dln2);
 572         if (ret < 0)
 573                 return ret;
 574
 575         return dln2_print_serialno(dln2);
 576 }
 577
 578 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 579 {
 580         int i;
 581
 582         for (i = 0; i < DLN2_MAX_URBS; i++) {
 583                 usb_free_urb(dln2->rx_urb[i]);
 584                 kfree(dln2->rx_buf[i]);
 585         }
 586 }
 587
 588 static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
 589 {
 590         int i;
 591
 592         for (i = 0; i < DLN2_MAX_URBS; i++)
 593                 usb_kill_urb(dln2->rx_urb[i]);
 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         const int rx_max_size = DLN2_RX_BUF_SIZE;
 608
 609         for (i = 0; i < DLN2_MAX_URBS; i++) {
 610                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 611                 if (!dln2->rx_buf[i])
 612                         return -ENOMEM;
 613
 614                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 615                 if (!dln2->rx_urb[i])
 616                         return -ENOMEM;
 617
 618                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 619                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 620                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 621         }
 622
 623         return 0;
 624 }
 625
 626 static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
 627 {
 628         struct device *dev = &dln2->interface->dev;
 629         int ret;
 630         int i;
 631
 632         for (i = 0; i < DLN2_MAX_URBS; i++) {
 633                 ret = usb_submit_urb(dln2->rx_urb[i], gfp);
 634                 if (ret < 0) {
 635                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 636                         return ret;
 637                 }
 638         }
 639
 640         return 0;
 641 }
 642
 643 static struct dln2_platform_data dln2_pdata_gpio = {
 644         .handle = DLN2_HANDLE_GPIO,
 645 };
 646
 647 /* Only one I2C port seems to be supported on current hardware */
 648 static struct dln2_platform_data dln2_pdata_i2c = {
 649         .handle = DLN2_HANDLE_I2C,
 650         .port = 0,
 651 };
 652
 653 /* Only one SPI port supported */
 654 static struct dln2_platform_data dln2_pdata_spi = {
 655         .handle = DLN2_HANDLE_SPI,
 656         .port = 0,
 657 };
 658
 659 static const struct mfd_cell dln2_devs[] = {
 660         {
 661                 .name = "dln2-gpio",
 662                 .platform_data = &dln2_pdata_gpio,
 663                 .pdata_size = sizeof(struct dln2_platform_data),
 664         },
 665         {
 666                 .name = "dln2-i2c",
 667                 .platform_data = &dln2_pdata_i2c,
 668                 .pdata_size = sizeof(struct dln2_platform_data),
 669         },
 670         {
 671                 .name = "dln2-spi",
 672                 .platform_data = &dln2_pdata_spi,
 673                 .pdata_size = sizeof(struct dln2_platform_data),
 674         },
 675 };
 676
 677 static void dln2_stop(struct dln2_dev *dln2)
 678 {
 679         int i, j;
 680
 681         /* don't allow starting new transfers */
 682         spin_lock(&dln2->disconnect_lock);
 683         dln2->disconnect = true;
 684         spin_unlock(&dln2->disconnect_lock);
 685
 686         /* cancel in progress transfers */
 687         for (i = 0; i < DLN2_HANDLES; i++) {
 688                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 689                 unsigned long flags;
 690
 691                 spin_lock_irqsave(&rxs->lock, flags);
 692
 693                 /* cancel all response waiters */
 694                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 695                         struct dln2_rx_context *rxc = &rxs->slots[j];
 696
 697                         if (rxc->in_use)
 698                                 complete(&rxc->done);
 699                 }
 700
 701                 spin_unlock_irqrestore(&rxs->lock, flags);
 702         }
 703
 704         /* wait for transfers to end */
 705         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 706
 707         dln2_stop_rx_urbs(dln2);
 708 }
 709
 710 static void dln2_disconnect(struct usb_interface *interface)
 711 {
 712         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 713
 714         dln2_stop(dln2);
 715
 716         mfd_remove_devices(&interface->dev);
 717
 718         dln2_free(dln2);
 719 }
 720
 721 static int dln2_probe(struct usb_interface *interface,
 722                       const struct usb_device_id *usb_id)
 723 {
 724         struct usb_host_interface *hostif = interface->cur_altsetting;
 725         struct device *dev = &interface->dev;
 726         struct dln2_dev *dln2;
 727         int ret;
 728         int i, j;
 729
 730         if (hostif->desc.bInterfaceNumber != 0 ||
 731             hostif->desc.bNumEndpoints < 2)
 732                 return -ENODEV;
 733
 734         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 735         if (!dln2)
 736                 return -ENOMEM;
 737
 738         dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
 739         dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
 740         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 741         dln2->interface = interface;
 742         usb_set_intfdata(interface, dln2);
 743         init_waitqueue_head(&dln2->disconnect_wq);
 744
 745         for (i = 0; i < DLN2_HANDLES; i++) {
 746                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 747                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 748                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 749                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 750         }
 751
 752         spin_lock_init(&dln2->event_cb_lock);
 753         spin_lock_init(&dln2->disconnect_lock);
 754         INIT_LIST_HEAD(&dln2->event_cb_list);
 755
 756         ret = dln2_setup_rx_urbs(dln2, hostif);
 757         if (ret)
 758                 goto out_free;
 759
 760         ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
 761         if (ret)
 762                 goto out_stop_rx;
 763
 764         ret = dln2_hw_init(dln2);
 765         if (ret < 0) {
 766                 dev_err(dev, "failed to initialize hardware\n");
 767                 goto out_stop_rx;
 768         }
 769
 770         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 771         if (ret != 0) {
 772                 dev_err(dev, "failed to add mfd devices to core\n");
 773                 goto out_stop_rx;
 774         }
 775
 776         return 0;
 777
 778 out_stop_rx:
 779         dln2_stop_rx_urbs(dln2);
 780
 781 out_free:
 782         dln2_free(dln2);
 783
 784         return ret;
 785 }
 786
 787 static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
 788 {
 789         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 790
 791         dln2_stop(dln2);
 792
 793         return 0;
 794 }
 795
 796 static int dln2_resume(struct usb_interface *iface)
 797 {
 798         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 799
 800         dln2->disconnect = false;
 801
 802         return dln2_start_rx_urbs(dln2, GFP_NOIO);
 803 }
 804
 805 static const struct usb_device_id dln2_table[] = {
 806         { USB_DEVICE(0xa257, 0x2013) },
 807         { }
 808 };
 809
 810 MODULE_DEVICE_TABLE(usb, dln2_table);
 811
 812 static struct usb_driver dln2_driver = {
 813         .name = "dln2",
 814         .probe = dln2_probe,
 815         .disconnect = dln2_disconnect,
 816         .id_table = dln2_table,
 817         .suspend = dln2_suspend,
 818         .resume = dln2_resume,
 819 };
 820
 821 module_usb_driver(dln2_driver);
 822
 823 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 824 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 825 MODULE_LICENSE("GPL v2");