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