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/mutex.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/mfd/core.h>
  20 #include <linux/mfd/dln2.h>
  21 #include <linux/rculist.h>
  22
  23 struct dln2_header {
  24         __le16 size;
  25         __le16 id;
  26         __le16 echo;
  27         __le16 handle;
  28 };
  29
  30 struct dln2_response {
  31         struct dln2_header hdr;
  32         __le16 result;
  33 };
  34
  35 #define DLN2_GENERIC_MODULE_ID          0x00
  36 #define DLN2_GENERIC_CMD(cmd)           DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
  37 #define CMD_GET_DEVICE_VER              DLN2_GENERIC_CMD(0x30)
  38 #define CMD_GET_DEVICE_SN               DLN2_GENERIC_CMD(0x31)
  39
  40 #define DLN2_HW_ID                      0x200
  41 #define DLN2_USB_TIMEOUT                200     /* in ms */
  42 #define DLN2_MAX_RX_SLOTS               16
  43 #define DLN2_MAX_URBS                   16
  44 #define DLN2_RX_BUF_SIZE                512
  45
  46 enum dln2_handle {
  47         DLN2_HANDLE_EVENT = 0,          /* don't change, hardware defined */
  48         DLN2_HANDLE_CTRL,
  49         DLN2_HANDLE_GPIO,
  50         DLN2_HANDLE_I2C,
  51         DLN2_HANDLE_SPI,
  52         DLN2_HANDLE_ADC,
  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                 unsigned long flags;
 286
 287                 spin_lock_irqsave(&dln2->event_cb_lock, flags);
 288                 dln2_run_event_callbacks(dln2, id, echo, data, len);
 289                 spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
 290         } else {
 291                 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
 292                 if (dln2_transfer_complete(dln2, urb, handle, echo))
 293                         return;
 294         }
 295
 296 out:
 297         err = usb_submit_urb(urb, GFP_ATOMIC);
 298         if (err < 0)
 299                 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 300 }
 301
 302 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
 303                            int *obuf_len, gfp_t gfp)
 304 {
 305         int len;
 306         void *buf;
 307         struct dln2_header *hdr;
 308
 309         len = *obuf_len + sizeof(*hdr);
 310         buf = kmalloc(len, gfp);
 311         if (!buf)
 312                 return NULL;
 313
 314         hdr = (struct dln2_header *)buf;
 315         hdr->id = cpu_to_le16(cmd);
 316         hdr->size = cpu_to_le16(len);
 317         hdr->echo = cpu_to_le16(echo);
 318         hdr->handle = cpu_to_le16(handle);
 319
 320         memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
 321
 322         *obuf_len = len;
 323
 324         return buf;
 325 }
 326
 327 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
 328                           const void *obuf, int obuf_len)
 329 {
 330         int ret = 0;
 331         int len = obuf_len;
 332         void *buf;
 333         int actual;
 334
 335         buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
 336         if (!buf)
 337                 return -ENOMEM;
 338
 339         ret = usb_bulk_msg(dln2->usb_dev,
 340                            usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
 341                            buf, len, &actual, DLN2_USB_TIMEOUT);
 342
 343         kfree(buf);
 344
 345         return ret;
 346 }
 347
 348 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
 349 {
 350         struct dln2_mod_rx_slots *rxs;
 351         unsigned long flags;
 352
 353         if (dln2->disconnect) {
 354                 *slot = -ENODEV;
 355                 return true;
 356         }
 357
 358         rxs = &dln2->mod_rx_slots[handle];
 359
 360         spin_lock_irqsave(&rxs->lock, flags);
 361
 362         *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
 363
 364         if (*slot < DLN2_MAX_RX_SLOTS) {
 365                 struct dln2_rx_context *rxc = &rxs->slots[*slot];
 366
 367                 set_bit(*slot, rxs->bmap);
 368                 rxc->in_use = true;
 369         }
 370
 371         spin_unlock_irqrestore(&rxs->lock, flags);
 372
 373         return *slot < DLN2_MAX_RX_SLOTS;
 374 }
 375
 376 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
 377 {
 378         int ret;
 379         int slot;
 380
 381         /*
 382          * No need to timeout here, the wait is bounded by the timeout in
 383          * _dln2_transfer.
 384          */
 385         ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
 386                                        find_free_slot(dln2, handle, &slot));
 387         if (ret < 0)
 388                 return ret;
 389
 390         return slot;
 391 }
 392
 393 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
 394 {
 395         struct dln2_mod_rx_slots *rxs;
 396         struct urb *urb = NULL;
 397         unsigned long flags;
 398         struct dln2_rx_context *rxc;
 399
 400         rxs = &dln2->mod_rx_slots[handle];
 401
 402         spin_lock_irqsave(&rxs->lock, flags);
 403
 404         clear_bit(slot, rxs->bmap);
 405
 406         rxc = &rxs->slots[slot];
 407         rxc->in_use = false;
 408         urb = rxc->urb;
 409         rxc->urb = NULL;
 410         reinit_completion(&rxc->done);
 411
 412         spin_unlock_irqrestore(&rxs->lock, flags);
 413
 414         if (urb) {
 415                 int err;
 416                 struct device *dev = &dln2->interface->dev;
 417
 418                 err = usb_submit_urb(urb, GFP_KERNEL);
 419                 if (err < 0)
 420                         dev_err(dev, "failed to resubmit RX URB: %d\n", err);
 421         }
 422
 423         wake_up_interruptible(&rxs->wq);
 424 }
 425
 426 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
 427                           const void *obuf, unsigned obuf_len,
 428                           void *ibuf, unsigned *ibuf_len)
 429 {
 430         int ret = 0;
 431         int rx_slot;
 432         struct dln2_response *rsp;
 433         struct dln2_rx_context *rxc;
 434         struct device *dev = &dln2->interface->dev;
 435         const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
 436         struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
 437         int size;
 438
 439         spin_lock(&dln2->disconnect_lock);
 440         if (!dln2->disconnect)
 441                 dln2->active_transfers++;
 442         else
 443                 ret = -ENODEV;
 444         spin_unlock(&dln2->disconnect_lock);
 445
 446         if (ret)
 447                 return ret;
 448
 449         rx_slot = alloc_rx_slot(dln2, handle);
 450         if (rx_slot < 0) {
 451                 ret = rx_slot;
 452                 goto out_decr;
 453         }
 454
 455         ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
 456         if (ret < 0) {
 457                 dev_err(dev, "USB write failed: %d\n", ret);
 458                 goto out_free_rx_slot;
 459         }
 460
 461         rxc = &rxs->slots[rx_slot];
 462
 463         ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
 464         if (ret <= 0) {
 465                 if (!ret)
 466                         ret = -ETIMEDOUT;
 467                 goto out_free_rx_slot;
 468         } else {
 469                 ret = 0;
 470         }
 471
 472         if (dln2->disconnect) {
 473                 ret = -ENODEV;
 474                 goto out_free_rx_slot;
 475         }
 476
 477         /* if we got here we know that the response header has been checked */
 478         rsp = rxc->urb->transfer_buffer;
 479         size = le16_to_cpu(rsp->hdr.size);
 480
 481         if (size < sizeof(*rsp)) {
 482                 ret = -EPROTO;
 483                 goto out_free_rx_slot;
 484         }
 485
 486         if (le16_to_cpu(rsp->result) > 0x80) {
 487                 dev_dbg(dev, "%d received response with error %d\n",
 488                         handle, le16_to_cpu(rsp->result));
 489                 ret = -EREMOTEIO;
 490                 goto out_free_rx_slot;
 491         }
 492
 493         if (!ibuf)
 494                 goto out_free_rx_slot;
 495
 496         if (*ibuf_len > size - sizeof(*rsp))
 497                 *ibuf_len = size - sizeof(*rsp);
 498
 499         memcpy(ibuf, rsp + 1, *ibuf_len);
 500
 501 out_free_rx_slot:
 502         free_rx_slot(dln2, handle, rx_slot);
 503 out_decr:
 504         spin_lock(&dln2->disconnect_lock);
 505         dln2->active_transfers--;
 506         spin_unlock(&dln2->disconnect_lock);
 507         if (dln2->disconnect)
 508                 wake_up(&dln2->disconnect_wq);
 509
 510         return ret;
 511 }
 512
 513 int dln2_transfer(struct platform_device *pdev, u16 cmd,
 514                   const void *obuf, unsigned obuf_len,
 515                   void *ibuf, unsigned *ibuf_len)
 516 {
 517         struct dln2_platform_data *dln2_pdata;
 518         struct dln2_dev *dln2;
 519         u16 handle;
 520
 521         dln2 = dev_get_drvdata(pdev->dev.parent);
 522         dln2_pdata = dev_get_platdata(&pdev->dev);
 523         handle = dln2_pdata->handle;
 524
 525         return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
 526                               ibuf_len);
 527 }
 528 EXPORT_SYMBOL(dln2_transfer);
 529
 530 static int dln2_check_hw(struct dln2_dev *dln2)
 531 {
 532         int ret;
 533         __le32 hw_type;
 534         int len = sizeof(hw_type);
 535
 536         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
 537                              NULL, 0, &hw_type, &len);
 538         if (ret < 0)
 539                 return ret;
 540         if (len < sizeof(hw_type))
 541                 return -EREMOTEIO;
 542
 543         if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
 544                 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
 545                         le32_to_cpu(hw_type));
 546                 return -ENODEV;
 547         }
 548
 549         return 0;
 550 }
 551
 552 static int dln2_print_serialno(struct dln2_dev *dln2)
 553 {
 554         int ret;
 555         __le32 serial_no;
 556         int len = sizeof(serial_no);
 557         struct device *dev = &dln2->interface->dev;
 558
 559         ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
 560                              &serial_no, &len);
 561         if (ret < 0)
 562                 return ret;
 563         if (len < sizeof(serial_no))
 564                 return -EREMOTEIO;
 565
 566         dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
 567
 568         return 0;
 569 }
 570
 571 static int dln2_hw_init(struct dln2_dev *dln2)
 572 {
 573         int ret;
 574
 575         ret = dln2_check_hw(dln2);
 576         if (ret < 0)
 577                 return ret;
 578
 579         return dln2_print_serialno(dln2);
 580 }
 581
 582 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
 583 {
 584         int i;
 585
 586         for (i = 0; i < DLN2_MAX_URBS; i++) {
 587                 usb_free_urb(dln2->rx_urb[i]);
 588                 kfree(dln2->rx_buf[i]);
 589         }
 590 }
 591
 592 static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
 593 {
 594         int i;
 595
 596         for (i = 0; i < DLN2_MAX_URBS; i++)
 597                 usb_kill_urb(dln2->rx_urb[i]);
 598 }
 599
 600 static void dln2_free(struct dln2_dev *dln2)
 601 {
 602         dln2_free_rx_urbs(dln2);
 603         usb_put_dev(dln2->usb_dev);
 604         kfree(dln2);
 605 }
 606
 607 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
 608                               struct usb_host_interface *hostif)
 609 {
 610         int i;
 611         const int rx_max_size = DLN2_RX_BUF_SIZE;
 612
 613         for (i = 0; i < DLN2_MAX_URBS; i++) {
 614                 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
 615                 if (!dln2->rx_buf[i])
 616                         return -ENOMEM;
 617
 618                 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 619                 if (!dln2->rx_urb[i])
 620                         return -ENOMEM;
 621
 622                 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
 623                                   usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
 624                                   dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
 625         }
 626
 627         return 0;
 628 }
 629
 630 static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
 631 {
 632         struct device *dev = &dln2->interface->dev;
 633         int ret;
 634         int i;
 635
 636         for (i = 0; i < DLN2_MAX_URBS; i++) {
 637                 ret = usb_submit_urb(dln2->rx_urb[i], gfp);
 638                 if (ret < 0) {
 639                         dev_err(dev, "failed to submit RX URB: %d\n", ret);
 640                         return ret;
 641                 }
 642         }
 643
 644         return 0;
 645 }
 646
 647 enum {
 648         DLN2_ACPI_MATCH_GPIO    = 0,
 649         DLN2_ACPI_MATCH_I2C     = 1,
 650         DLN2_ACPI_MATCH_SPI     = 2,
 651         DLN2_ACPI_MATCH_ADC     = 3,
 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 /* Only one ADC port supported */
 683 static struct dln2_platform_data dln2_pdata_adc = {
 684         .handle = DLN2_HANDLE_ADC,
 685         .port = 0,
 686 };
 687
 688 static struct mfd_cell_acpi_match dln2_acpi_match_adc = {
 689         .adr = DLN2_ACPI_MATCH_ADC,
 690 };
 691
 692 static const struct mfd_cell dln2_devs[] = {
 693         {
 694                 .name = "dln2-gpio",
 695                 .acpi_match = &dln2_acpi_match_gpio,
 696                 .platform_data = &dln2_pdata_gpio,
 697                 .pdata_size = sizeof(struct dln2_platform_data),
 698         },
 699         {
 700                 .name = "dln2-i2c",
 701                 .acpi_match = &dln2_acpi_match_i2c,
 702                 .platform_data = &dln2_pdata_i2c,
 703                 .pdata_size = sizeof(struct dln2_platform_data),
 704         },
 705         {
 706                 .name = "dln2-spi",
 707                 .acpi_match = &dln2_acpi_match_spi,
 708                 .platform_data = &dln2_pdata_spi,
 709                 .pdata_size = sizeof(struct dln2_platform_data),
 710         },
 711         {
 712                 .name = "dln2-adc",
 713                 .acpi_match = &dln2_acpi_match_adc,
 714                 .platform_data = &dln2_pdata_adc,
 715                 .pdata_size = sizeof(struct dln2_platform_data),
 716         },
 717 };
 718
 719 static void dln2_stop(struct dln2_dev *dln2)
 720 {
 721         int i, j;
 722
 723         /* don't allow starting new transfers */
 724         spin_lock(&dln2->disconnect_lock);
 725         dln2->disconnect = true;
 726         spin_unlock(&dln2->disconnect_lock);
 727
 728         /* cancel in progress transfers */
 729         for (i = 0; i < DLN2_HANDLES; i++) {
 730                 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
 731                 unsigned long flags;
 732
 733                 spin_lock_irqsave(&rxs->lock, flags);
 734
 735                 /* cancel all response waiters */
 736                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
 737                         struct dln2_rx_context *rxc = &rxs->slots[j];
 738
 739                         if (rxc->in_use)
 740                                 complete(&rxc->done);
 741                 }
 742
 743                 spin_unlock_irqrestore(&rxs->lock, flags);
 744         }
 745
 746         /* wait for transfers to end */
 747         wait_event(dln2->disconnect_wq, !dln2->active_transfers);
 748
 749         dln2_stop_rx_urbs(dln2);
 750 }
 751
 752 static void dln2_disconnect(struct usb_interface *interface)
 753 {
 754         struct dln2_dev *dln2 = usb_get_intfdata(interface);
 755
 756         dln2_stop(dln2);
 757
 758         mfd_remove_devices(&interface->dev);
 759
 760         dln2_free(dln2);
 761 }
 762
 763 static int dln2_probe(struct usb_interface *interface,
 764                       const struct usb_device_id *usb_id)
 765 {
 766         struct usb_host_interface *hostif = interface->cur_altsetting;
 767         struct usb_endpoint_descriptor *epin;
 768         struct usb_endpoint_descriptor *epout;
 769         struct device *dev = &interface->dev;
 770         struct dln2_dev *dln2;
 771         int ret;
 772         int i, j;
 773
 774         if (hostif->desc.bInterfaceNumber != 0)
 775                 return -ENODEV;
 776
 777         ret = usb_find_common_endpoints(hostif, &epin, &epout, NULL, NULL);
 778         if (ret)
 779                 return ret;
 780
 781         dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
 782         if (!dln2)
 783                 return -ENOMEM;
 784
 785         dln2->ep_out = epout->bEndpointAddress;
 786         dln2->ep_in = epin->bEndpointAddress;
 787         dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
 788         dln2->interface = interface;
 789         usb_set_intfdata(interface, dln2);
 790         init_waitqueue_head(&dln2->disconnect_wq);
 791
 792         for (i = 0; i < DLN2_HANDLES; i++) {
 793                 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
 794                 spin_lock_init(&dln2->mod_rx_slots[i].lock);
 795                 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
 796                         init_completion(&dln2->mod_rx_slots[i].slots[j].done);
 797         }
 798
 799         spin_lock_init(&dln2->event_cb_lock);
 800         spin_lock_init(&dln2->disconnect_lock);
 801         INIT_LIST_HEAD(&dln2->event_cb_list);
 802
 803         ret = dln2_setup_rx_urbs(dln2, hostif);
 804         if (ret)
 805                 goto out_free;
 806
 807         ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
 808         if (ret)
 809                 goto out_stop_rx;
 810
 811         ret = dln2_hw_init(dln2);
 812         if (ret < 0) {
 813                 dev_err(dev, "failed to initialize hardware\n");
 814                 goto out_stop_rx;
 815         }
 816
 817         ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
 818         if (ret != 0) {
 819                 dev_err(dev, "failed to add mfd devices to core\n");
 820                 goto out_stop_rx;
 821         }
 822
 823         return 0;
 824
 825 out_stop_rx:
 826         dln2_stop_rx_urbs(dln2);
 827
 828 out_free:
 829         usb_put_dev(dln2->usb_dev);
 830         dln2_free(dln2);
 831
 832         return ret;
 833 }
 834
 835 static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
 836 {
 837         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 838
 839         dln2_stop(dln2);
 840
 841         return 0;
 842 }
 843
 844 static int dln2_resume(struct usb_interface *iface)
 845 {
 846         struct dln2_dev *dln2 = usb_get_intfdata(iface);
 847
 848         dln2->disconnect = false;
 849
 850         return dln2_start_rx_urbs(dln2, GFP_NOIO);
 851 }
 852
 853 static const struct usb_device_id dln2_table[] = {
 854         { USB_DEVICE(0xa257, 0x2013) },
 855         { }
 856 };
 857
 858 MODULE_DEVICE_TABLE(usb, dln2_table);
 859
 860 static struct usb_driver dln2_driver = {
 861         .name = "dln2",
 862         .probe = dln2_probe,
 863         .disconnect = dln2_disconnect,
 864         .id_table = dln2_table,
 865         .suspend = dln2_suspend,
 866         .resume = dln2_resume,
 867 };
 868
 869 module_usb_driver(dln2_driver);
 870
 871 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
 872 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
 873 MODULE_LICENSE("GPL v2");