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                 unsigned long flags;
 294
 295                 spin_lock_irqsave(&dln2->event_cb_lock, flags);
 296                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 297                 spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 298         } else {
 299                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 300                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 301                         return;
 302         }
 303
 304 out:
 305         err = usb_submit_urb(urb, GFP_ATOMIC);
 306         if (err < 0)
 307                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 308 }
 309
 310 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 311                            int *obuf_len, gfp_t gfp)
 312 {
 313         int len;
 314         void *buf;
 315         struct dln2_header *hdr;
 316
 317         len = *obuf_len + sizeof(*hdr);
 318         buf = kmalloc(len, gfp);
 319         if (!buf)
 320                 return NULL;
 321
 322         hdr = (struct dln2_header *)buf;
 323         hdr->id = cpu_to_le16(cmd);
 324         hdr->size = cpu_to_le16(len);
 325         hdr->echo = cpu_to_le16(echo);
 326         hdr->handle = cpu_to_le16(handle);
 327
 328         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 329
 330         *obuf_len = len;
 331
 332         return buf;
 333 }
 334
 335 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 336                           const void *obuf, int obuf_len)
 337 {
 338         int ret = 0;
 339         int len = obuf_len;
 340         void *buf;
 341         int actual;
 342
 343         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 344         if (!buf)
 345                 return -ENOMEM;
 346
 347         ret = usb_bulk_msg(dln2->usb_dev,
 348                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 349                            buf, len, &actual, DLN2_USB_TIMEOUT);
 350
 351         kfree(buf);
 352
 353         return ret;
 354 }
 355
 356 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 357 {
 358         struct dln2_mod_rx_slots *rxs;
 359         unsigned long flags;
 360
 361         if (dln2->disconnect) {
 362                 *slot = -ENODEV;
 363                 return true;
 364         }
 365
 366         rxs = &dln2->mod_rx_slots[handle];
 367
 368         spin_lock_irqsave(&rxs->lock, flags);
 369
 370         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 371
 372         if (*slot < DLN2_MAX_RX_SLOTS) {
 373                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 374
 375                 set_bit(*slot, rxs->bmap);
 376                 rxc->in_use = true;
 377         }
 378
 379         spin_unlock_irqrestore(&rxs->lock, flags);
 380
 381         return *slot < DLN2_MAX_RX_SLOTS;
 382 }
 383
 384 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 385 {
 386         int ret;
 387         int slot;
 388
 389         /*
 390          * No need to timeout here, the wait is bounded by the timeout in
 391          * _dln2_transfer.
 392          */
 393         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 394                                        find_free_slot(dln2, handle, &slot));
 395         if (ret < 0)
 396                 return ret;
 397
 398         return slot;
 399 }
 400
 401 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 402 {
 403         struct dln2_mod_rx_slots *rxs;
 404         struct urb *urb = NULL;
 405         unsigned long flags;
 406         struct dln2_rx_context *rxc;
 407
 408         rxs = &dln2->mod_rx_slots[handle];
 409
 410         spin_lock_irqsave(&rxs->lock, flags);
 411
 412         clear_bit(slot, rxs->bmap);
 413
 414         rxc = &rxs->slots[slot];
 415         rxc->in_use = false;
 416         urb = rxc->urb;
 417         rxc->urb = NULL;
 418         reinit_completion(&rxc->done);
 419
 420         spin_unlock_irqrestore(&rxs->lock, flags);
 421
 422         if (urb) {
 423                 int err;
 424                 struct device *dev = &dln2->interface->dev;
 425
 426                 err = usb_submit_urb(urb, GFP_KERNEL);
 427                 if (err < 0)
 428                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 429         }
 430
 431         wake_up_interruptible(&rxs->wq);
 432 }
 433
 434 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 435                           const void *obuf, unsigned obuf_len,
 436                           void *ibuf, unsigned *ibuf_len)
 437 {
 438         int ret = 0;
 439         int rx_slot;
 440         struct dln2_response *rsp;
 441         struct dln2_rx_context *rxc;
 442         struct device *dev = &dln2->interface->dev;
 443         const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
 444         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 445         int size;
 446
 447         spin_lock(&dln2->disconnect_lock);
 448         if (!dln2->disconnect)
 449                 dln2->active_transfers++;
 450         else
 451                 ret = -ENODEV;
 452         spin_unlock(&dln2->disconnect_lock);
 453
 454         if (ret)
 455                 return ret;
 456
 457         rx_slot = alloc_rx_slot(dln2, handle);
 458         if (rx_slot < 0) {
 459                 ret = rx_slot;
 460                 goto out_decr;
 461         }
 462
 463         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 464         if (ret < 0) {
 465                 dev_err(dev, "USB write failed: %d\n", ret);
 466                 goto out_free_rx_slot;
 467         }
 468
 469         rxc = &rxs->slots[rx_slot];
 470
 471         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 472         if (ret <= 0) {
 473                 if (!ret)
 474                         ret = -ETIMEDOUT;
 475                 goto out_free_rx_slot;
 476         } else {
 477                 ret = 0;
 478         }
 479
 480         if (dln2->disconnect) {
 481                 ret = -ENODEV;
 482                 goto out_free_rx_slot;
 483         }
 484
 485         /* if we got here we know that the response header has been checked */
 486         rsp = rxc->urb->transfer_buffer;
 487         size = le16_to_cpu(rsp->hdr.size);
 488
 489         if (size < sizeof(*rsp)) {
 490                 ret = -EPROTO;
 491                 goto out_free_rx_slot;
 492         }
 493
 494         if (le16_to_cpu(rsp->result) > 0x80) {
 495                 dev_dbg(dev, "%d received response with error %d\n",
 496                         handle, le16_to_cpu(rsp->result));
 497                 ret = -EREMOTEIO;
 498                 goto out_free_rx_slot;
 499         }
 500
 501         if (!ibuf)
 502                 goto out_free_rx_slot;
 503
 504         if (*ibuf_len > size - sizeof(*rsp))
 505                 *ibuf_len = size - sizeof(*rsp);
 506
 507         memcpy(ibuf, rsp + 1, *ibuf_len);
 508
 509 out_free_rx_slot:
 510         free_rx_slot(dln2, handle, rx_slot);
 511 out_decr:
 512         spin_lock(&dln2->disconnect_lock);
 513         dln2->active_transfers--;
 514         spin_unlock(&dln2->disconnect_lock);
 515         if (dln2->disconnect)
 516                 wake_up(&dln2->disconnect_wq);
 517
 518         return ret;
 519 }
 520
 521 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 522                   const void *obuf, unsigned obuf_len,
 523                   void *ibuf, unsigned *ibuf_len)
 524 {
 525         struct dln2_platform_data *dln2_pdata;
 526         struct dln2_dev *dln2;
 527         u16 handle;
 528
 529         dln2 = dev_get_drvdata(pdev->dev.parent);
 530         dln2_pdata = dev_get_platdata(&pdev->dev);
 531         handle = dln2_pdata->handle;
 532
 533         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 534                               ibuf_len);
 535 }
 536 EXPORT_SYMBOL(dln2_transfer);
 537
 538 static int dln2_check_hw(struct dln2_dev *dln2)
 539 {
 540         int ret;
 541         __le32 hw_type;
 542         int len = sizeof(hw_type);
 543
 544         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 545                              NULL, 0, &hw_type, &len);
 546         if (ret < 0)
 547                 return ret;
 548         if (len < sizeof(hw_type))
 549                 return -EREMOTEIO;
 550
 551         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 552                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 553                         le32_to_cpu(hw_type));
 554                 return -ENODEV;
 555         }
 556
 557         return 0;
 558 }
 559
 560 static int dln2_print_serialno(struct dln2_dev *dln2)
 561 {
 562         int ret;
 563         __le32 serial_no;
 564         int len = sizeof(serial_no);
 565         struct device *dev = &dln2->interface->dev;
 566
 567         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 568                              &serial_no, &len);
 569         if (ret < 0)
 570                 return ret;
 571         if (len < sizeof(serial_no))
 572                 return -EREMOTEIO;
 573
 574         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 575
 576         return 0;
 577 }
 578
 579 static int dln2_hw_init(struct dln2_dev *dln2)
 580 {
 581         int ret;
 582
 583         ret = dln2_check_hw(dln2);
 584         if (ret < 0)
 585                 return ret;
 586
 587         return dln2_print_serialno(dln2);
 588 }
 589
 590 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 591 {
 592         int i;
 593
 594         for (i = 0; i < DLN2_MAX_URBS; i++) {
 595                 usb_free_urb(dln2->rx_urb[i]);
 596                 kfree(dln2->rx_buf[i]);
 597         }
 598 }
 599
 600 static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
 601 {
 602         int i;
 603
 604         for (i = 0; i < DLN2_MAX_URBS; i++)
 605                 usb_kill_urb(dln2->rx_urb[i]);
 606 }
 607
 608 static void dln2_free(struct dln2_dev *dln2)
 609 {
 610         dln2_free_rx_urbs(dln2);
 611         usb_put_dev(dln2->usb_dev);
 612         kfree(dln2);
 613 }
 614
 615 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
 616                               struct usb_host_interface *hostif)
 617 {
 618         int i;
 619         const int rx_max_size = DLN2_RX_BUF_SIZE;
 620
 621         for (i = 0; i < DLN2_MAX_URBS; i++) {
 622                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 623                 if (!dln2->rx_buf[i])
 624                         return -ENOMEM;
 625
 626                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 627                 if (!dln2->rx_urb[i])
 628                         return -ENOMEM;
 629
 630                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 631                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 632                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 633         }
 634
 635         return 0;
 636 }
 637
 638 static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
 639 {
 640         struct device *dev = &dln2->interface->dev;
 641         int ret;
 642         int i;
 643
 644         for (i = 0; i < DLN2_MAX_URBS; i++) {
 645                 ret = usb_submit_urb(dln2->rx_urb[i], gfp);
 646                 if (ret < 0) {
 647                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 648                         return ret;
 649                 }
 650         }
 651
 652         return 0;
 653 }
 654
 655 static struct dln2_platform_data dln2_pdata_gpio = {
 656         .handle = DLN2_HANDLE_GPIO,
 657 };
 658
 659 /* Only one I2C port seems to be supported on current hardware */
 660 static struct dln2_platform_data dln2_pdata_i2c = {
 661         .handle = DLN2_HANDLE_I2C,
 662         .port = 0,
 663 };
 664
 665 /* Only one SPI port supported */
 666 static struct dln2_platform_data dln2_pdata_spi = {
 667         .handle = DLN2_HANDLE_SPI,
 668         .port = 0,
 669 };
 670
 671 static const struct mfd_cell dln2_devs[] = {
 672         {
 673                 .name = "dln2-gpio",
 674                 .platform_data = &dln2_pdata_gpio,
 675                 .pdata_size = sizeof(struct dln2_platform_data),
 676         },
 677         {
 678                 .name = "dln2-i2c",
 679                 .platform_data = &dln2_pdata_i2c,
 680                 .pdata_size = sizeof(struct dln2_platform_data),
 681         },
 682         {
 683                 .name = "dln2-spi",
 684                 .platform_data = &dln2_pdata_spi,
 685                 .pdata_size = sizeof(struct dln2_platform_data),
 686         },
 687 };
 688
 689 static void dln2_stop(struct dln2_dev *dln2)
 690 {
 691         int i, j;
 692
 693         /* don't allow starting new transfers */
 694         spin_lock(&dln2->disconnect_lock);
 695         dln2->disconnect = true;
 696         spin_unlock(&dln2->disconnect_lock);
 697
 698         /* cancel in progress transfers */
 699         for (i = 0; i < DLN2_HANDLES; i++) {
 700                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 701                 unsigned long flags;
 702
 703                 spin_lock_irqsave(&rxs->lock, flags);
 704
 705                 /* cancel all response waiters */
 706                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 707                         struct dln2_rx_context *rxc = &rxs->slots[j];
 708
 709                         if (rxc->in_use)
 710                                 complete(&rxc->done);
 711                 }
 712
 713                 spin_unlock_irqrestore(&rxs->lock, flags);
 714         }
 715
 716         /* wait for transfers to end */
 717         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 718
 719         dln2_stop_rx_urbs(dln2);
 720 }
 721
 722 static void dln2_disconnect(struct usb_interface *interface)
 723 {
 724         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 725
 726         dln2_stop(dln2);
 727
 728         mfd_remove_devices(&interface->dev);
 729
 730         dln2_free(dln2);
 731 }
 732
 733 static int dln2_probe(struct usb_interface *interface,
 734                       const struct usb_device_id *usb_id)
 735 {
 736         struct usb_host_interface *hostif = interface->cur_altsetting;
 737         struct usb_endpoint_descriptor *epin;
 738         struct usb_endpoint_descriptor *epout;
 739         struct device *dev = &interface->dev;
 740         struct dln2_dev *dln2;
 741         int ret;
 742         int i, j;
 743
 744         if (hostif->desc.bInterfaceNumber != 0 ||
 745             hostif->desc.bNumEndpoints < 2)
 746                 return -ENODEV;
 747
 748         epout = &hostif->endpoint[DLN2_EP_OUT].desc;
 749         if (!usb_endpoint_is_bulk_out(epout))
 750                 return -ENODEV;
 751         epin = &hostif->endpoint[DLN2_EP_IN].desc;
 752         if (!usb_endpoint_is_bulk_in(epin))
 753                 return -ENODEV;
 754
 755         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 756         if (!dln2)
 757                 return -ENOMEM;
 758
 759         dln2->ep_out = epout->bEndpointAddress;
 760         dln2->ep_in = epin->bEndpointAddress;
 761         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 762         dln2->interface = interface;
 763         usb_set_intfdata(interface, dln2);
 764         init_waitqueue_head(&dln2->disconnect_wq);
 765
 766         for (i = 0; i < DLN2_HANDLES; i++) {
 767                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 768                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 769                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 770                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 771         }
 772
 773         spin_lock_init(&dln2->event_cb_lock);
 774         spin_lock_init(&dln2->disconnect_lock);
 775         INIT_LIST_HEAD(&dln2->event_cb_list);
 776
 777         ret = dln2_setup_rx_urbs(dln2, hostif);
 778         if (ret)
 779                 goto out_free;
 780
 781         ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
 782         if (ret)
 783                 goto out_stop_rx;
 784
 785         ret = dln2_hw_init(dln2);
 786         if (ret < 0) {
 787                 dev_err(dev, "failed to initialize hardware\n");
 788                 goto out_stop_rx;
 789         }
 790
 791         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 792         if (ret != 0) {
 793                 dev_err(dev, "failed to add mfd devices to core\n");
 794                 goto out_stop_rx;
 795         }
 796
 797         return 0;
 798
 799 out_stop_rx:
 800         dln2_stop_rx_urbs(dln2);
 801
 802 out_free:
 803         dln2_free(dln2);
 804
 805         return ret;
 806 }
 807
 808 static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
 809 {
 810         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 811
 812         dln2_stop(dln2);
 813
 814         return 0;
 815 }
 816
 817 static int dln2_resume(struct usb_interface *iface)
 818 {
 819         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 820
 821         dln2->disconnect = false;
 822
 823         return dln2_start_rx_urbs(dln2, GFP_NOIO);
 824 }
 825
 826 static const struct usb_device_id dln2_table[] = {
 827         { USB_DEVICE(0xa257, 0x2013) },
 828         { }
 829 };
 830
 831 MODULE_DEVICE_TABLE(usb, dln2_table);
 832
 833 static struct usb_driver dln2_driver = {
 834         .name = "dln2",
 835         .probe = dln2_probe,
 836         .disconnect = dln2_disconnect,
 837         .id_table = dln2_table,
 838         .suspend = dln2_suspend,
 839         .resume = dln2_resume,
 840 };
 841
 842 module_usb_driver(dln2_driver);
 843
 844 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 845 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 846 MODULE_LICENSE("GPL v2");