Pileus Git - ~andy/linux/blob - drivers/staging/gdm724x/gdm_mux.c

   1 /*
   2  * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/usb.h>
  19 #include <linux/errno.h>
  20 #include <linux/init.h>
  21 #include <linux/tty.h>
  22 #include <linux/tty_driver.h>
  23 #include <linux/tty_flip.h>
  24 #include <linux/slab.h>
  25 #include <linux/usb/cdc.h>
  26
  27 #include "gdm_mux.h"
  28
  29 static struct workqueue_struct *mux_rx_wq;
  30
  31 static u16 packet_type[TTY_MAX_COUNT] = {0xF011, 0xF010};
  32
  33 #define USB_DEVICE_CDC_DATA(vid, pid) \
  34         .match_flags = \
  35                 USB_DEVICE_ID_MATCH_DEVICE |\
  36                 USB_DEVICE_ID_MATCH_INT_CLASS |\
  37                 USB_DEVICE_ID_MATCH_INT_SUBCLASS,\
  38         .idVendor = vid,\
  39         .idProduct = pid,\
  40         .bInterfaceClass = USB_CLASS_COMM,\
  41         .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM
  42
  43 static const struct usb_device_id id_table[] = {
  44         { USB_DEVICE_CDC_DATA(0x1076, 0x8000) }, /* GCT GDM7240 */
  45         { USB_DEVICE_CDC_DATA(0x1076, 0x8f00) }, /* GCT GDM7243 */
  46         { USB_DEVICE_CDC_DATA(0x1076, 0x9000) }, /* GCT GDM7243 */
  47         { USB_DEVICE_CDC_DATA(0x1d74, 0x2300) }, /* LGIT Phoenix */
  48         {}
  49 };
  50
  51
  52 MODULE_DEVICE_TABLE(usb, id_table);
  53
  54 static int packet_type_to_index(u16 packetType)
  55 {
  56         int i;
  57
  58         for (i = 0; i < TTY_MAX_COUNT; i++) {
  59                 if (packet_type[i] == packetType)
  60                         return i;
  61         }
  62
  63         return -1;
  64 }
  65
  66 static struct mux_tx *alloc_mux_tx(int len)
  67 {
  68         struct mux_tx *t = NULL;
  69
  70         t = kzalloc(sizeof(struct mux_tx), GFP_ATOMIC);
  71         if (!t)
  72                 return NULL;
  73
  74         t->urb = usb_alloc_urb(0, GFP_ATOMIC);
  75         t->buf = kmalloc(MUX_TX_MAX_SIZE, GFP_ATOMIC);
  76         if (!t->urb || !t->buf) {
  77                 usb_free_urb(t->urb);
  78                 kfree(t->buf);
  79                 kfree(t);
  80                 return NULL;
  81         }
  82
  83         return t;
  84 }
  85
  86 static void free_mux_tx(struct mux_tx *t)
  87 {
  88         if (t) {
  89                 usb_free_urb(t->urb);
  90                 kfree(t->buf);
  91                 kfree(t);
  92         }
  93 }
  94
  95 static struct mux_rx *alloc_mux_rx(void)
  96 {
  97         struct mux_rx *r = NULL;
  98
  99         r = kzalloc(sizeof(struct mux_rx), GFP_KERNEL);
 100         if (!r)
 101                 return NULL;
 102
 103         r->urb = usb_alloc_urb(0, GFP_KERNEL);
 104         r->buf = kmalloc(MUX_RX_MAX_SIZE, GFP_KERNEL);
 105         if (!r->urb || !r->buf) {
 106                 usb_free_urb(r->urb);
 107                 kfree(r->buf);
 108                 kfree(r);
 109                 return NULL;
 110         }
 111
 112         return r;
 113 }
 114
 115 static void free_mux_rx(struct mux_rx *r)
 116 {
 117         if (r) {
 118                 usb_free_urb(r->urb);
 119                 kfree(r->buf);
 120                 kfree(r);
 121         }
 122 }
 123
 124 static struct mux_rx *get_rx_struct(struct rx_cxt *rx)
 125 {
 126         struct mux_rx *r;
 127         unsigned long flags;
 128
 129         spin_lock_irqsave(&rx->free_list_lock, flags);
 130
 131         if (list_empty(&rx->rx_free_list)) {
 132                 spin_unlock_irqrestore(&rx->free_list_lock, flags);
 133                 return NULL;
 134         }
 135
 136         r = list_entry(rx->rx_free_list.prev, struct mux_rx, free_list);
 137         list_del(&r->free_list);
 138
 139         spin_unlock_irqrestore(&rx->free_list_lock, flags);
 140
 141         return r;
 142 }
 143
 144 static void put_rx_struct(struct rx_cxt *rx, struct mux_rx *r)
 145 {
 146         unsigned long flags;
 147
 148         spin_lock_irqsave(&rx->free_list_lock, flags);
 149         list_add_tail(&r->free_list, &rx->rx_free_list);
 150         spin_unlock_irqrestore(&rx->free_list_lock, flags);
 151 }
 152
 153
 154 static int up_to_host(struct mux_rx *r)
 155 {
 156         struct mux_dev *mux_dev = (struct mux_dev *)r->mux_dev;
 157         struct mux_pkt_header *mux_header;
 158         unsigned int start_flag;
 159         unsigned int payload_size;
 160         unsigned short packet_type;
 161         int dummy_cnt;
 162         u32 packet_size_sum = r->offset;
 163         int index;
 164         int ret = TO_HOST_INVALID_PACKET;
 165         int len = r->len;
 166
 167         while (1) {
 168                 mux_header = (struct mux_pkt_header *)(r->buf + packet_size_sum);
 169                 start_flag = __le32_to_cpu(mux_header->start_flag);
 170                 payload_size = __le32_to_cpu(mux_header->payload_size);
 171                 packet_type = __le16_to_cpu(mux_header->packet_type);
 172
 173                 if (start_flag != START_FLAG) {
 174                         pr_err("invalid START_FLAG %x\n", start_flag);
 175                         break;
 176                 }
 177
 178                 dummy_cnt = ALIGN(MUX_HEADER_SIZE + payload_size, 4);
 179
 180                 if (len - packet_size_sum <
 181                         MUX_HEADER_SIZE + payload_size + dummy_cnt) {
 182                         pr_err("invalid payload : %d %d %04x\n",
 183                                payload_size, len, packet_type);
 184                         break;
 185                 }
 186
 187                 index = packet_type_to_index(packet_type);
 188                 if (index < 0) {
 189                         pr_err("invalid index %d\n", index);
 190                         break;
 191                 }
 192
 193                 ret = r->callback(mux_header->data,
 194                                 payload_size,
 195                                 index,
 196                                 mux_dev->tty_dev,
 197                                 RECV_PACKET_PROCESS_CONTINUE
 198                                 );
 199                 if (ret == TO_HOST_BUFFER_REQUEST_FAIL) {
 200                         r->offset += packet_size_sum;
 201                         break;
 202                 }
 203
 204                 packet_size_sum += MUX_HEADER_SIZE + payload_size + dummy_cnt;
 205                 if (len - packet_size_sum <= MUX_HEADER_SIZE + 2) {
 206                         ret = r->callback(NULL,
 207                                         0,
 208                                         index,
 209                                         mux_dev->tty_dev,
 210                                         RECV_PACKET_PROCESS_COMPLETE
 211                                         );
 212                         break;
 213                 }
 214         }
 215
 216         return ret;
 217 }
 218
 219 static void do_rx(struct work_struct *work)
 220 {
 221         struct mux_dev *mux_dev =
 222                 container_of(work, struct mux_dev , work_rx.work);
 223         struct mux_rx *r;
 224         struct rx_cxt *rx = (struct rx_cxt *)&mux_dev->rx;
 225         unsigned long flags;
 226         int ret = 0;
 227
 228         while (1) {
 229                 spin_lock_irqsave(&rx->to_host_lock, flags);
 230                 if (list_empty(&rx->to_host_list)) {
 231                         spin_unlock_irqrestore(&rx->to_host_lock, flags);
 232                         break;
 233                 }
 234                 r = list_entry(rx->to_host_list.next, struct mux_rx, to_host_list);
 235                 list_del(&r->to_host_list);
 236                 spin_unlock_irqrestore(&rx->to_host_lock, flags);
 237
 238                 ret = up_to_host(r);
 239                 if (ret == TO_HOST_BUFFER_REQUEST_FAIL)
 240                         pr_err("failed to send mux data to host\n");
 241                 else
 242                         put_rx_struct(rx, r);
 243         }
 244 }
 245
 246 static void remove_rx_submit_list(struct mux_rx *r, struct rx_cxt *rx)
 247 {
 248         unsigned long flags;
 249         struct mux_rx   *r_remove, *r_remove_next;
 250
 251         spin_lock_irqsave(&rx->submit_list_lock, flags);
 252         list_for_each_entry_safe(r_remove, r_remove_next, &rx->rx_submit_list, rx_submit_list) {
 253                 if (r == r_remove)
 254                         list_del(&r->rx_submit_list);
 255         }
 256         spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 257 }
 258
 259 static void gdm_mux_rcv_complete(struct urb *urb)
 260 {
 261         struct mux_rx *r = urb->context;
 262         struct mux_dev *mux_dev = (struct mux_dev *)r->mux_dev;
 263         struct rx_cxt *rx = &mux_dev->rx;
 264         unsigned long flags;
 265
 266         remove_rx_submit_list(r, rx);
 267
 268         if (urb->status) {
 269                 if (mux_dev->usb_state == PM_NORMAL)
 270                         pr_err("%s: urb status error %d\n",
 271                                __func__, urb->status);
 272                 put_rx_struct(rx, r);
 273         } else {
 274                 r->len = r->urb->actual_length;
 275                 spin_lock_irqsave(&rx->to_host_lock, flags);
 276                 list_add_tail(&r->to_host_list, &rx->to_host_list);
 277                 queue_work(mux_rx_wq, &mux_dev->work_rx.work);
 278                 spin_unlock_irqrestore(&rx->to_host_lock, flags);
 279         }
 280 }
 281
 282 static int gdm_mux_recv(void *priv_dev,
 283                         int (*cb)(void *data, int len, int tty_index, struct tty_dev *tty_dev, int complete)
 284                         )
 285 {
 286         struct mux_dev *mux_dev = priv_dev;
 287         struct usb_device *usbdev = mux_dev->usbdev;
 288         struct mux_rx *r;
 289         struct rx_cxt *rx = &mux_dev->rx;
 290         unsigned long flags;
 291         int ret;
 292
 293         if (!usbdev) {
 294                 pr_err("device is disconnected\n");
 295                 return -ENODEV;
 296         }
 297
 298         r = get_rx_struct(rx);
 299         if (!r) {
 300                 pr_err("get_rx_struct fail\n");
 301                 return -ENOMEM;
 302         }
 303
 304         r->offset = 0;
 305         r->mux_dev = (void *)mux_dev;
 306         r->callback = cb;
 307         mux_dev->rx_cb = cb;
 308
 309         usb_fill_bulk_urb(r->urb,
 310                           usbdev,
 311                           usb_rcvbulkpipe(usbdev, 0x86),
 312                           r->buf,
 313                           MUX_RX_MAX_SIZE,
 314                           gdm_mux_rcv_complete,
 315                           r);
 316
 317         spin_lock_irqsave(&rx->submit_list_lock, flags);
 318         list_add_tail(&r->rx_submit_list, &rx->rx_submit_list);
 319         spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 320
 321         ret = usb_submit_urb(r->urb, GFP_KERNEL);
 322
 323         if (ret) {
 324                 spin_lock_irqsave(&rx->submit_list_lock, flags);
 325                 list_del(&r->rx_submit_list);
 326                 spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 327
 328                 put_rx_struct(rx, r);
 329
 330                 pr_err("usb_submit_urb ret=%d\n", ret);
 331         }
 332
 333         usb_mark_last_busy(usbdev);
 334
 335         return ret;
 336 }
 337
 338 static void gdm_mux_send_complete(struct urb *urb)
 339 {
 340         struct mux_tx *t = urb->context;
 341
 342         if (urb->status == -ECONNRESET) {
 343                 pr_info("CONNRESET\n");
 344                 free_mux_tx(t);
 345                 return;
 346         }
 347
 348         if (t->callback)
 349                 t->callback(t->cb_data);
 350
 351         free_mux_tx(t);
 352 }
 353
 354 static int gdm_mux_send(void *priv_dev, void *data, int len, int tty_index,
 355                         void (*cb)(void *data), void *cb_data)
 356 {
 357         struct mux_dev *mux_dev = priv_dev;
 358         struct usb_device *usbdev = mux_dev->usbdev;
 359         struct mux_pkt_header *mux_header;
 360         struct mux_tx *t = NULL;
 361         static u32 seq_num = 1;
 362         int dummy_cnt;
 363         int total_len;
 364         int ret;
 365         unsigned long flags;
 366
 367         if (mux_dev->usb_state == PM_SUSPEND) {
 368                 ret = usb_autopm_get_interface(mux_dev->intf);
 369                 if (!ret)
 370                         usb_autopm_put_interface(mux_dev->intf);
 371         }
 372
 373         spin_lock_irqsave(&mux_dev->write_lock, flags);
 374
 375         dummy_cnt = ALIGN(MUX_HEADER_SIZE + len, 4);
 376
 377         total_len = len + MUX_HEADER_SIZE + dummy_cnt;
 378
 379         t = alloc_mux_tx(total_len);
 380         if (!t) {
 381                 pr_err("alloc_mux_tx fail\n");
 382                 spin_unlock_irqrestore(&mux_dev->write_lock, flags);
 383                 return -ENOMEM;
 384         }
 385
 386         mux_header = (struct mux_pkt_header *)t->buf;
 387         mux_header->start_flag = __cpu_to_le32(START_FLAG);
 388         mux_header->seq_num = __cpu_to_le32(seq_num++);
 389         mux_header->payload_size = __cpu_to_le32((u32)len);
 390         mux_header->packet_type = __cpu_to_le16(packet_type[tty_index]);
 391
 392         memcpy(t->buf+MUX_HEADER_SIZE, data, len);
 393         memset(t->buf+MUX_HEADER_SIZE+len, 0, dummy_cnt);
 394
 395         t->len = total_len;
 396         t->callback = cb;
 397         t->cb_data = cb_data;
 398
 399         usb_fill_bulk_urb(t->urb,
 400                           usbdev,
 401                           usb_sndbulkpipe(usbdev, 5),
 402                           t->buf,
 403                           total_len,
 404                           gdm_mux_send_complete,
 405                           t);
 406
 407         ret = usb_submit_urb(t->urb, GFP_ATOMIC);
 408
 409         spin_unlock_irqrestore(&mux_dev->write_lock, flags);
 410
 411         if (ret)
 412                 pr_err("usb_submit_urb Error: %d\n", ret);
 413
 414         usb_mark_last_busy(usbdev);
 415
 416         return ret;
 417 }
 418
 419 static int gdm_mux_send_control(void *priv_dev, int request, int value, void *buf, int len)
 420 {
 421         struct mux_dev *mux_dev = priv_dev;
 422         struct usb_device *usbdev = mux_dev->usbdev;
 423         int ret;
 424
 425         ret = usb_control_msg(usbdev,
 426                               usb_sndctrlpipe(usbdev, 0),
 427                               request,
 428                               USB_RT_ACM,
 429                               value,
 430                               2,
 431                               buf,
 432                               len,
 433                               5000
 434                              );
 435
 436         if (ret < 0)
 437                 pr_err("usb_control_msg error: %d\n", ret);
 438
 439         return ret < 0 ? ret : 0;
 440 }
 441
 442 static void release_usb(struct mux_dev *mux_dev)
 443 {
 444         struct rx_cxt           *rx = &mux_dev->rx;
 445         struct mux_rx           *r, *r_next;
 446         unsigned long           flags;
 447
 448         cancel_delayed_work(&mux_dev->work_rx);
 449
 450         spin_lock_irqsave(&rx->submit_list_lock, flags);
 451         list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list) {
 452                 spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 453                 usb_kill_urb(r->urb);
 454                 spin_lock_irqsave(&rx->submit_list_lock, flags);
 455         }
 456         spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 457
 458         spin_lock_irqsave(&rx->free_list_lock, flags);
 459         list_for_each_entry_safe(r, r_next, &rx->rx_free_list, free_list) {
 460                 list_del(&r->free_list);
 461                 free_mux_rx(r);
 462         }
 463         spin_unlock_irqrestore(&rx->free_list_lock, flags);
 464
 465         spin_lock_irqsave(&rx->to_host_lock, flags);
 466         list_for_each_entry_safe(r, r_next, &rx->to_host_list, to_host_list) {
 467                 if (r->mux_dev == (void *)mux_dev) {
 468                         list_del(&r->to_host_list);
 469                         free_mux_rx(r);
 470                 }
 471         }
 472         spin_unlock_irqrestore(&rx->to_host_lock, flags);
 473 }
 474
 475
 476 static int init_usb(struct mux_dev *mux_dev)
 477 {
 478         struct mux_rx *r;
 479         struct rx_cxt *rx = &mux_dev->rx;
 480         int ret = 0;
 481         int i;
 482
 483         spin_lock_init(&mux_dev->write_lock);
 484         INIT_LIST_HEAD(&rx->to_host_list);
 485         INIT_LIST_HEAD(&rx->rx_submit_list);
 486         INIT_LIST_HEAD(&rx->rx_free_list);
 487         spin_lock_init(&rx->to_host_lock);
 488         spin_lock_init(&rx->submit_list_lock);
 489         spin_lock_init(&rx->free_list_lock);
 490
 491         for (i = 0; i < MAX_ISSUE_NUM * 2; i++) {
 492                 r = alloc_mux_rx();
 493                 if (r == NULL) {
 494                         ret = -ENOMEM;
 495                         break;
 496                 }
 497
 498                 list_add(&r->free_list, &rx->rx_free_list);
 499         }
 500
 501         INIT_DELAYED_WORK(&mux_dev->work_rx, do_rx);
 502
 503         return ret;
 504 }
 505
 506 static int gdm_mux_probe(struct usb_interface *intf, const struct usb_device_id *id)
 507 {
 508         struct mux_dev *mux_dev;
 509         struct tty_dev *tty_dev;
 510         u16 idVendor, idProduct;
 511         int bInterfaceNumber;
 512         int ret;
 513         int i;
 514         struct usb_device *usbdev = interface_to_usbdev(intf);
 515         bInterfaceNumber = intf->cur_altsetting->desc.bInterfaceNumber;
 516
 517         idVendor = __le16_to_cpu(usbdev->descriptor.idVendor);
 518         idProduct = __le16_to_cpu(usbdev->descriptor.idProduct);
 519
 520         pr_info("mux vid = 0x%04x pid = 0x%04x\n", idVendor, idProduct);
 521
 522         if (bInterfaceNumber != 2)
 523                 return -ENODEV;
 524
 525         mux_dev = kzalloc(sizeof(struct mux_dev), GFP_KERNEL);
 526         if (!mux_dev)
 527                 return -ENOMEM;
 528
 529         tty_dev = kzalloc(sizeof(struct tty_dev), GFP_KERNEL);
 530         if (!tty_dev) {
 531                 ret = -ENOMEM;
 532                 goto err_free_mux;
 533         }
 534
 535         mux_dev->usbdev = usbdev;
 536         mux_dev->control_intf = intf;
 537
 538         ret = init_usb(mux_dev);
 539         if (ret)
 540                 goto err_free_usb;
 541
 542         tty_dev->priv_dev = (void *)mux_dev;
 543         tty_dev->send_func = gdm_mux_send;
 544         tty_dev->recv_func = gdm_mux_recv;
 545         tty_dev->send_control = gdm_mux_send_control;
 546
 547         ret = register_lte_tty_device(tty_dev, &intf->dev);
 548         if (ret)
 549                 goto err_unregister_tty;
 550
 551         for (i = 0; i < TTY_MAX_COUNT; i++)
 552                 mux_dev->tty_dev = tty_dev;
 553
 554         mux_dev->intf = intf;
 555         mux_dev->usb_state = PM_NORMAL;
 556
 557         usb_get_dev(usbdev);
 558         usb_set_intfdata(intf, tty_dev);
 559
 560         return 0;
 561
 562 err_unregister_tty:
 563         unregister_lte_tty_device(tty_dev);
 564 err_free_usb:
 565         release_usb(mux_dev);
 566         kfree(tty_dev);
 567 err_free_mux:
 568         kfree(mux_dev);
 569
 570         return ret;
 571 }
 572
 573 static void gdm_mux_disconnect(struct usb_interface *intf)
 574 {
 575         struct tty_dev *tty_dev;
 576         struct mux_dev *mux_dev;
 577         struct usb_device *usbdev = interface_to_usbdev(intf);
 578
 579         tty_dev = usb_get_intfdata(intf);
 580
 581         mux_dev = tty_dev->priv_dev;
 582
 583         release_usb(mux_dev);
 584         unregister_lte_tty_device(tty_dev);
 585
 586         kfree(mux_dev);
 587         kfree(tty_dev);
 588
 589         usb_put_dev(usbdev);
 590 }
 591
 592 static int gdm_mux_suspend(struct usb_interface *intf, pm_message_t pm_msg)
 593 {
 594         struct tty_dev *tty_dev;
 595         struct mux_dev *mux_dev;
 596         struct rx_cxt *rx;
 597         struct mux_rx *r, *r_next;
 598         unsigned long flags;
 599
 600         tty_dev = usb_get_intfdata(intf);
 601         mux_dev = tty_dev->priv_dev;
 602         rx = &mux_dev->rx;
 603
 604         if (mux_dev->usb_state != PM_NORMAL) {
 605                 pr_err("usb suspend - invalid state\n");
 606                 return -1;
 607         }
 608
 609         mux_dev->usb_state = PM_SUSPEND;
 610
 611
 612         spin_lock_irqsave(&rx->submit_list_lock, flags);
 613         list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list) {
 614                 spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 615                 usb_kill_urb(r->urb);
 616                 spin_lock_irqsave(&rx->submit_list_lock, flags);
 617         }
 618         spin_unlock_irqrestore(&rx->submit_list_lock, flags);
 619
 620         return 0;
 621 }
 622
 623 static int gdm_mux_resume(struct usb_interface *intf)
 624 {
 625         struct tty_dev *tty_dev;
 626         struct mux_dev *mux_dev;
 627         u8 i;
 628
 629         tty_dev = usb_get_intfdata(intf);
 630         mux_dev = tty_dev->priv_dev;
 631
 632         if (mux_dev->usb_state != PM_SUSPEND) {
 633                 pr_err("usb resume - invalid state\n");
 634                 return -1;
 635         }
 636
 637         mux_dev->usb_state = PM_NORMAL;
 638
 639         for (i = 0; i < MAX_ISSUE_NUM; i++)
 640                 gdm_mux_recv(mux_dev, mux_dev->rx_cb);
 641
 642         return 0;
 643 }
 644
 645 static struct usb_driver gdm_mux_driver = {
 646         .name = "gdm_mux",
 647         .probe = gdm_mux_probe,
 648         .disconnect = gdm_mux_disconnect,
 649         .id_table = id_table,
 650         .supports_autosuspend = 1,
 651         .suspend = gdm_mux_suspend,
 652         .resume = gdm_mux_resume,
 653         .reset_resume = gdm_mux_resume,
 654 };
 655
 656 static int __init gdm_usb_mux_init(void)
 657 {
 658
 659         mux_rx_wq = create_workqueue("mux_rx_wq");
 660         if (mux_rx_wq == NULL) {
 661                 pr_err("work queue create fail\n");
 662                 return -1;
 663         }
 664
 665         register_lte_tty_driver();
 666
 667         return usb_register(&gdm_mux_driver);
 668 }
 669
 670 static void __exit gdm_usb_mux_exit(void)
 671 {
 672         unregister_lte_tty_driver();
 673
 674         if (mux_rx_wq) {
 675                 flush_workqueue(mux_rx_wq);
 676                 destroy_workqueue(mux_rx_wq);
 677         }
 678
 679         usb_deregister(&gdm_mux_driver);
 680 }
 681
 682 module_init(gdm_usb_mux_init);
 683 module_exit(gdm_usb_mux_exit);
 684
 685 MODULE_DESCRIPTION("GCT LTE TTY Device Driver");
 686 MODULE_LICENSE("GPL");