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 enum dln2_endpoint {
  94         DLN2_EP_OUT     = 0,
  95         DLN2_EP_IN      = 1,
  96 };
  97
  98 struct dln2_dev {
  99         struct usb_device *usb_dev;
 100         struct usb_interface *interface;
 101         u8 ep_in;
 102         u8 ep_out;
 103
 104         struct urb *rx_urb[DLN2_MAX_URBS];
 105         void *rx_buf[DLN2_MAX_URBS];
 106
 107         struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
 108
 109         struct list_head event_cb_list;
 110         spinlock_t event_cb_lock;
 111
 112         bool disconnect;
 113         int active_transfers;
 114         wait_queue_head_t disconnect_wq;
 115         spinlock_t disconnect_lock;
 116 };
 117
 118 struct dln2_event_cb_entry {
 119         struct list_head list;
 120         u16 id;
 121         struct platform_device *pdev;
 122         dln2_event_cb_t callback;
 123 };
 124
 125 int dln2_register_event_cb(struct platform_device *pdev, u16 id,
 126                            dln2_event_cb_t event_cb)
 127 {
 128         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 129         struct dln2_event_cb_entry *i, *entry;
 130         unsigned long flags;
 131         int ret = 0;
 132
 133         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 134         if (!entry)
 135                 return -ENOMEM;
 136
 137         entry->id = id;
 138         entry->callback = event_cb;
 139         entry->pdev = pdev;
 140
 141         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 142
 143         list_for_each_entry(i, &dln2->event_cb_list, list) {
 144                 if (i->id == id) {
 145                         ret = -EBUSY;
 146                         break;
 147                 }
 148         }
 149
 150         if (!ret)
 151                 list_add_rcu(&entry->list, &dln2->event_cb_list);
 152
 153         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 154
 155         if (ret)
 156                 kfree(entry);
 157
 158         return ret;
 159 }
 160 EXPORT_SYMBOL(dln2_register_event_cb);
 161
 162 void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
 163 {
 164         struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
 165         struct dln2_event_cb_entry *i;
 166         unsigned long flags;
 167         bool found = false;
 168
 169         spin_lock_irqsave(&dln2->event_cb_lock, flags);
 170
 171         list_for_each_entry(i, &dln2->event_cb_list, list) {
 172                 if (i->id == id) {
 173                         list_del_rcu(&i->list);
 174                         found = true;
 175                         break;
 176                 }
 177         }
 178
 179         spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 180
 181         if (found) {
 182                 synchronize_rcu();
 183                 kfree(i);
 184         }
 185 }
 186 EXPORT_SYMBOL(dln2_unregister_event_cb);
 187
 188 /*
 189  * Returns true if a valid transfer slot is found. In this case the URB must not
 190  * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
 191  * is woke up. It will be resubmitted there.
 192  */
 193 static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
 194                                    u16 handle, u16 rx_slot)
 195 {
 196         struct device *dev = &dln2->interface->dev;
 197         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 198         struct dln2_rx_context *rxc;
 199         unsigned long flags;
 200         bool valid_slot = false;
 201
 202         if (rx_slot >= DLN2_MAX_RX_SLOTS)
 203                 goto out;
 204
 205         rxc = &rxs->slots[rx_slot];
 206
 207         spin_lock_irqsave(&rxs->lock, flags);
 208         if (rxc->in_use && !rxc->urb) {
 209                 rxc->urb = urb;
 210                 complete(&rxc->done);
 211                 valid_slot = true;
 212         }
 213         spin_unlock_irqrestore(&rxs->lock, flags);
 214
 215 out:
 216         if (!valid_slot)
 217                 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
 218
 219         return valid_slot;
 220 }
 221
 222 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
 223                                      void *data, int len)
 224 {
 225         struct dln2_event_cb_entry *i;
 226
 227         rcu_read_lock();
 228
 229         list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
 230                 if (i->id == id) {
 231                         i->callback(i->pdev, echo, data, len);
 232                         break;
 233                 }
 234         }
 235
 236         rcu_read_unlock();
 237 }
 238
 239 static void dln2_rx(struct urb *urb)
 240 {
 241         struct dln2_dev *dln2 = urb->context;
 242         struct dln2_header *hdr = urb->transfer_buffer;
 243         struct device *dev = &dln2->interface->dev;
 244         u16 id, echo, handle, size;
 245         u8 *data;
 246         int len;
 247         int err;
 248
 249         switch (urb->status) {
 250         case 0:
 251                 /* success */
 252                 break;
 253         case -ECONNRESET:
 254         case -ENOENT:
 255         case -ESHUTDOWN:
 256         case -EPIPE:
 257                 /* this urb is terminated, clean up */
 258                 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
 259                 return;
 260         default:
 261                 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
 262                 goto out;
 263         }
 264
 265         if (urb->actual_length < sizeof(struct dln2_header)) {
 266                 dev_err(dev, "short response: %d\n", urb->actual_length);
 267                 goto out;
 268         }
 269
 270         handle = le16_to_cpu(hdr->handle);
 271         id = le16_to_cpu(hdr->id);
 272         echo = le16_to_cpu(hdr->echo);
 273         size = le16_to_cpu(hdr->size);
 274
 275         if (size != urb->actual_length) {
 276                 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
 277                         handle, id, echo, size, urb->actual_length);
 278                 goto out;
 279         }
 280
 281         if (handle >= DLN2_HANDLES) {
 282                 dev_warn(dev, "invalid handle %d\n", handle);
 283                 goto out;
 284         }
 285
 286         data = urb->transfer_buffer + sizeof(struct dln2_header);
 287         len = urb->actual_length - sizeof(struct dln2_header);
 288
 289         if (handle == DLN2_HANDLE_EVENT) {
 290                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 291         } else {
 292                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 293                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 294                         return;
 295         }
 296
 297 out:
 298         err = usb_submit_urb(urb, GFP_ATOMIC);
 299         if (err < 0)
 300                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 301 }
 302
 303 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 304                            int *obuf_len, gfp_t gfp)
 305 {
 306         int len;
 307         void *buf;
 308         struct dln2_header *hdr;
 309
 310         len = *obuf_len + sizeof(*hdr);
 311         buf = kmalloc(len, gfp);
 312         if (!buf)
 313                 return NULL;
 314
 315         hdr = (struct dln2_header *)buf;
 316         hdr->id = cpu_to_le16(cmd);
 317         hdr->size = cpu_to_le16(len);
 318         hdr->echo = cpu_to_le16(echo);
 319         hdr->handle = cpu_to_le16(handle);
 320
 321         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 322
 323         *obuf_len = len;
 324
 325         return buf;
 326 }
 327
 328 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 329                           const void *obuf, int obuf_len)
 330 {
 331         int ret = 0;
 332         int len = obuf_len;
 333         void *buf;
 334         int actual;
 335
 336         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 337         if (!buf)
 338                 return -ENOMEM;
 339
 340         ret = usb_bulk_msg(dln2->usb_dev,
 341                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 342                            buf, len, &actual, DLN2_USB_TIMEOUT);
 343
 344         kfree(buf);
 345
 346         return ret;
 347 }
 348
 349 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 350 {
 351         struct dln2_mod_rx_slots *rxs;
 352         unsigned long flags;
 353
 354         if (dln2->disconnect) {
 355                 *slot = -ENODEV;
 356                 return true;
 357         }
 358
 359         rxs = &dln2->mod_rx_slots[handle];
 360
 361         spin_lock_irqsave(&rxs->lock, flags);
 362
 363         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 364
 365         if (*slot < DLN2_MAX_RX_SLOTS) {
 366                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 367
 368                 set_bit(*slot, rxs->bmap);
 369                 rxc->in_use = true;
 370         }
 371
 372         spin_unlock_irqrestore(&rxs->lock, flags);
 373
 374         return *slot < DLN2_MAX_RX_SLOTS;
 375 }
 376
 377 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 378 {
 379         int ret;
 380         int slot;
 381
 382         /*
 383          * No need to timeout here, the wait is bounded by the timeout in
 384          * _dln2_transfer.
 385          */
 386         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 387                                        find_free_slot(dln2, handle, &slot));
 388         if (ret < 0)
 389                 return ret;
 390
 391         return slot;
 392 }
 393
 394 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 395 {
 396         struct dln2_mod_rx_slots *rxs;
 397         struct urb *urb = NULL;
 398         unsigned long flags;
 399         struct dln2_rx_context *rxc;
 400
 401         rxs = &dln2->mod_rx_slots[handle];
 402
 403         spin_lock_irqsave(&rxs->lock, flags);
 404
 405         clear_bit(slot, rxs->bmap);
 406
 407         rxc = &rxs->slots[slot];
 408         rxc->in_use = false;
 409         urb = rxc->urb;
 410         rxc->urb = NULL;
 411         reinit_completion(&rxc->done);
 412
 413         spin_unlock_irqrestore(&rxs->lock, flags);
 414
 415         if (urb) {
 416                 int err;
 417                 struct device *dev = &dln2->interface->dev;
 418
 419                 err = usb_submit_urb(urb, GFP_KERNEL);
 420                 if (err < 0)
 421                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 422         }
 423
 424         wake_up_interruptible(&rxs->wq);
 425 }
 426
 427 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 428                           const void *obuf, unsigned obuf_len,
 429                           void *ibuf, unsigned *ibuf_len)
 430 {
 431         int ret = 0;
 432         int rx_slot;
 433         struct dln2_response *rsp;
 434         struct dln2_rx_context *rxc;
 435         struct device *dev = &dln2->interface->dev;
 436         const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
 437         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 438         int size;
 439
 440         spin_lock(&dln2->disconnect_lock);
 441         if (!dln2->disconnect)
 442                 dln2->active_transfers++;
 443         else
 444                 ret = -ENODEV;
 445         spin_unlock(&dln2->disconnect_lock);
 446
 447         if (ret)
 448                 return ret;
 449
 450         rx_slot = alloc_rx_slot(dln2, handle);
 451         if (rx_slot < 0) {
 452                 ret = rx_slot;
 453                 goto out_decr;
 454         }
 455
 456         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 457         if (ret < 0) {
 458                 dev_err(dev, "USB write failed: %d\n", ret);
 459                 goto out_free_rx_slot;
 460         }
 461
 462         rxc = &rxs->slots[rx_slot];
 463
 464         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 465         if (ret <= 0) {
 466                 if (!ret)
 467                         ret = -ETIMEDOUT;
 468                 goto out_free_rx_slot;
 469         } else {
 470                 ret = 0;
 471         }
 472
 473         if (dln2->disconnect) {
 474                 ret = -ENODEV;
 475                 goto out_free_rx_slot;
 476         }
 477
 478         /* if we got here we know that the response header has been checked */
 479         rsp = rxc->urb->transfer_buffer;
 480         size = le16_to_cpu(rsp->hdr.size);
 481
 482         if (size < sizeof(*rsp)) {
 483                 ret = -EPROTO;
 484                 goto out_free_rx_slot;
 485         }
 486
 487         if (le16_to_cpu(rsp->result) > 0x80) {
 488                 dev_dbg(dev, "%d received response with error %d\n",
 489                         handle, le16_to_cpu(rsp->result));
 490                 ret = -EREMOTEIO;
 491                 goto out_free_rx_slot;
 492         }
 493
 494         if (!ibuf)
 495                 goto out_free_rx_slot;
 496
 497         if (*ibuf_len > size - sizeof(*rsp))
 498                 *ibuf_len = size - sizeof(*rsp);
 499
 500         memcpy(ibuf, rsp + 1, *ibuf_len);
 501
 502 out_free_rx_slot:
 503         free_rx_slot(dln2, handle, rx_slot);
 504 out_decr:
 505         spin_lock(&dln2->disconnect_lock);
 506         dln2->active_transfers--;
 507         spin_unlock(&dln2->disconnect_lock);
 508         if (dln2->disconnect)
 509                 wake_up(&dln2->disconnect_wq);
 510
 511         return ret;
 512 }
 513
 514 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 515                   const void *obuf, unsigned obuf_len,
 516                   void *ibuf, unsigned *ibuf_len)
 517 {
 518         struct dln2_platform_data *dln2_pdata;
 519         struct dln2_dev *dln2;
 520         u16 handle;
 521
 522         dln2 = dev_get_drvdata(pdev->dev.parent);
 523         dln2_pdata = dev_get_platdata(&pdev->dev);
 524         handle = dln2_pdata->handle;
 525
 526         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 527                               ibuf_len);
 528 }
 529 EXPORT_SYMBOL(dln2_transfer);
 530
 531 static int dln2_check_hw(struct dln2_dev *dln2)
 532 {
 533         int ret;
 534         __le32 hw_type;
 535         int len = sizeof(hw_type);
 536
 537         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 538                              NULL, 0, &hw_type, &len);
 539         if (ret < 0)
 540                 return ret;
 541         if (len < sizeof(hw_type))
 542                 return -EREMOTEIO;
 543
 544         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 545                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 546                         le32_to_cpu(hw_type));
 547                 return -ENODEV;
 548         }
 549
 550         return 0;
 551 }
 552
 553 static int dln2_print_serialno(struct dln2_dev *dln2)
 554 {
 555         int ret;
 556         __le32 serial_no;
 557         int len = sizeof(serial_no);
 558         struct device *dev = &dln2->interface->dev;
 559
 560         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 561                              &serial_no, &len);
 562         if (ret < 0)
 563                 return ret;
 564         if (len < sizeof(serial_no))
 565                 return -EREMOTEIO;
 566
 567         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 568
 569         return 0;
 570 }
 571
 572 static int dln2_hw_init(struct dln2_dev *dln2)
 573 {
 574         int ret;
 575
 576         ret = dln2_check_hw(dln2);
 577         if (ret < 0)
 578                 return ret;
 579
 580         return dln2_print_serialno(dln2);
 581 }
 582
 583 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 584 {
 585         int i;
 586
 587         for (i = 0; i < DLN2_MAX_URBS; i++) {
 588                 usb_free_urb(dln2->rx_urb[i]);
 589                 kfree(dln2->rx_buf[i]);
 590         }
 591 }
 592
 593 static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
 594 {
 595         int i;
 596
 597         for (i = 0; i < DLN2_MAX_URBS; i++)
 598                 usb_kill_urb(dln2->rx_urb[i]);
 599 }
 600
 601 static void dln2_free(struct dln2_dev *dln2)
 602 {
 603         dln2_free_rx_urbs(dln2);
 604         usb_put_dev(dln2->usb_dev);
 605         kfree(dln2);
 606 }
 607
 608 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
 609                               struct usb_host_interface *hostif)
 610 {
 611         int i;
 612         const int rx_max_size = DLN2_RX_BUF_SIZE;
 613
 614         for (i = 0; i < DLN2_MAX_URBS; i++) {
 615                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 616                 if (!dln2->rx_buf[i])
 617                         return -ENOMEM;
 618
 619                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 620                 if (!dln2->rx_urb[i])
 621                         return -ENOMEM;
 622
 623                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 624                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 625                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 626         }
 627
 628         return 0;
 629 }
 630
 631 static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
 632 {
 633         struct device *dev = &dln2->interface->dev;
 634         int ret;
 635         int i;
 636
 637         for (i = 0; i < DLN2_MAX_URBS; i++) {
 638                 ret = usb_submit_urb(dln2->rx_urb[i], gfp);
 639                 if (ret < 0) {
 640                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 641                         return ret;
 642                 }
 643         }
 644
 645         return 0;
 646 }
 647
 648 enum {
 649         DLN2_ACPI_MATCH_GPIO    = 0,
 650         DLN2_ACPI_MATCH_I2C     = 1,
 651         DLN2_ACPI_MATCH_SPI     = 2,
 652 };
 653
 654 static struct dln2_platform_data dln2_pdata_gpio = {
 655         .handle = DLN2_HANDLE_GPIO,
 656 };
 657
 658 static struct mfd_cell_acpi_match dln2_acpi_match_gpio = {
 659         .adr = DLN2_ACPI_MATCH_GPIO,
 660 };
 661
 662 /* Only one I2C port seems to be supported on current hardware */
 663 static struct dln2_platform_data dln2_pdata_i2c = {
 664         .handle = DLN2_HANDLE_I2C,
 665         .port = 0,
 666 };
 667
 668 static struct mfd_cell_acpi_match dln2_acpi_match_i2c = {
 669         .adr = DLN2_ACPI_MATCH_I2C,
 670 };
 671
 672 /* Only one SPI port supported */
 673 static struct dln2_platform_data dln2_pdata_spi = {
 674         .handle = DLN2_HANDLE_SPI,
 675         .port = 0,
 676 };
 677
 678 static struct mfd_cell_acpi_match dln2_acpi_match_spi = {
 679         .adr = DLN2_ACPI_MATCH_SPI,
 680 };
 681
 682 static const struct mfd_cell dln2_devs[] = {
 683         {
 684                 .name = "dln2-gpio",
 685                 .acpi_match = &dln2_acpi_match_gpio,
 686                 .platform_data = &dln2_pdata_gpio,
 687                 .pdata_size = sizeof(struct dln2_platform_data),
 688         },
 689         {
 690                 .name = "dln2-i2c",
 691                 .acpi_match = &dln2_acpi_match_i2c,
 692                 .platform_data = &dln2_pdata_i2c,
 693                 .pdata_size = sizeof(struct dln2_platform_data),
 694         },
 695         {
 696                 .name = "dln2-spi",
 697                 .acpi_match = &dln2_acpi_match_spi,
 698                 .platform_data = &dln2_pdata_spi,
 699                 .pdata_size = sizeof(struct dln2_platform_data),
 700         },
 701 };
 702
 703 static void dln2_stop(struct dln2_dev *dln2)
 704 {
 705         int i, j;
 706
 707         /* don't allow starting new transfers */
 708         spin_lock(&dln2->disconnect_lock);
 709         dln2->disconnect = true;
 710         spin_unlock(&dln2->disconnect_lock);
 711
 712         /* cancel in progress transfers */
 713         for (i = 0; i < DLN2_HANDLES; i++) {
 714                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 715                 unsigned long flags;
 716
 717                 spin_lock_irqsave(&rxs->lock, flags);
 718
 719                 /* cancel all response waiters */
 720                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 721                         struct dln2_rx_context *rxc = &rxs->slots[j];
 722
 723                         if (rxc->in_use)
 724                                 complete(&rxc->done);
 725                 }
 726
 727                 spin_unlock_irqrestore(&rxs->lock, flags);
 728         }
 729
 730         /* wait for transfers to end */
 731         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 732
 733         dln2_stop_rx_urbs(dln2);
 734 }
 735
 736 static void dln2_disconnect(struct usb_interface *interface)
 737 {
 738         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 739
 740         dln2_stop(dln2);
 741
 742         mfd_remove_devices(&interface->dev);
 743
 744         dln2_free(dln2);
 745 }
 746
 747 static int dln2_probe(struct usb_interface *interface,
 748                       const struct usb_device_id *usb_id)
 749 {
 750         struct usb_host_interface *hostif = interface->cur_altsetting;
 751         struct usb_endpoint_descriptor *epin;
 752         struct usb_endpoint_descriptor *epout;
 753         struct device *dev = &interface->dev;
 754         struct dln2_dev *dln2;
 755         int ret;
 756         int i, j;
 757
 758         if (hostif->desc.bInterfaceNumber != 0 ||
 759             hostif->desc.bNumEndpoints < 2)
 760                 return -ENODEV;
 761
 762         epout = &hostif->endpoint[DLN2_EP_OUT].desc;
 763         if (!usb_endpoint_is_bulk_out(epout))
 764                 return -ENODEV;
 765         epin = &hostif->endpoint[DLN2_EP_IN].desc;
 766         if (!usb_endpoint_is_bulk_in(epin))
 767                 return -ENODEV;
 768
 769         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 770         if (!dln2)
 771                 return -ENOMEM;
 772
 773         dln2->ep_out = epout->bEndpointAddress;
 774         dln2->ep_in = epin->bEndpointAddress;
 775         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 776         dln2->interface = interface;
 777         usb_set_intfdata(interface, dln2);
 778         init_waitqueue_head(&dln2->disconnect_wq);
 779
 780         for (i = 0; i < DLN2_HANDLES; i++) {
 781                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 782                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 783                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 784                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 785         }
 786
 787         spin_lock_init(&dln2->event_cb_lock);
 788         spin_lock_init(&dln2->disconnect_lock);
 789         INIT_LIST_HEAD(&dln2->event_cb_list);
 790
 791         ret = dln2_setup_rx_urbs(dln2, hostif);
 792         if (ret)
 793                 goto out_free;
 794
 795         ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
 796         if (ret)
 797                 goto out_stop_rx;
 798
 799         ret = dln2_hw_init(dln2);
 800         if (ret < 0) {
 801                 dev_err(dev, "failed to initialize hardware\n");
 802                 goto out_stop_rx;
 803         }
 804
 805         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 806         if (ret != 0) {
 807                 dev_err(dev, "failed to add mfd devices to core\n");
 808                 goto out_stop_rx;
 809         }
 810
 811         return 0;
 812
 813 out_stop_rx:
 814         dln2_stop_rx_urbs(dln2);
 815
 816 out_free:
 817         dln2_free(dln2);
 818
 819         return ret;
 820 }
 821
 822 static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
 823 {
 824         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 825
 826         dln2_stop(dln2);
 827
 828         return 0;
 829 }
 830
 831 static int dln2_resume(struct usb_interface *iface)
 832 {
 833         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 834
 835         dln2->disconnect = false;
 836
 837         return dln2_start_rx_urbs(dln2, GFP_NOIO);
 838 }
 839
 840 static const struct usb_device_id dln2_table[] = {
 841         { USB_DEVICE(0xa257, 0x2013) },
 842         { }
 843 };
 844
 845 MODULE_DEVICE_TABLE(usb, dln2_table);
 846
 847 static struct usb_driver dln2_driver = {
 848         .name = "dln2",
 849         .probe = dln2_probe,
 850         .disconnect = dln2_disconnect,
 851         .id_table = dln2_table,
 852         .suspend = dln2_suspend,
 853         .resume = dln2_resume,
 854 };
 855
 856 module_usb_driver(dln2_driver);
 857
 858 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 859 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 860 MODULE_LICENSE("GPL v2");