cdc-acm.c 46.1 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722
/*
 * cdc-acm.c
 *
 * Copyright (c) 1999 Armin Fuerst	<fuerst@in.tum.de>
 * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
 * Copyright (c) 1999 Johannes Erdfelt	<johannes@erdfelt.com>
 * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
 * Copyright (c) 2004 Oliver Neukum	<oliver@neukum.name>
 * Copyright (c) 2005 David Kubicek	<dave@awk.cz>
 * Copyright (c) 2011 Johan Hovold	<jhovold@gmail.com>
 *
 * USB Abstract Control Model driver for USB modems and ISDN adapters
 *
 * Sponsored by SuSE
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#undef DEBUG
#undef VERBOSE_DEBUG

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/list.h>

#include "cdc-acm.h"


#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek, Johan Hovold"
#define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"

static struct usb_driver acm_driver;
static struct tty_driver *acm_tty_driver;
static struct acm *acm_table[ACM_TTY_MINORS];

static DEFINE_MUTEX(acm_table_lock);

/*
 * acm_table accessors
 */

/*
 * Look up an ACM structure by index. If found and not disconnected, increment
 * its refcount and return it with its mutex held.
 */
static struct acm *acm_get_by_index(unsigned index)
{
	struct acm *acm;

	mutex_lock(&acm_table_lock);
	acm = acm_table[index];
	if (acm) {
		mutex_lock(&acm->mutex);
		if (acm->disconnected) {
			mutex_unlock(&acm->mutex);
			acm = NULL;
		} else {
			tty_port_get(&acm->port);
			mutex_unlock(&acm->mutex);
		}
	}
	mutex_unlock(&acm_table_lock);
	return acm;
}

/*
 * Try to find an available minor number and if found, associate it with 'acm'.
 */
static int acm_alloc_minor(struct acm *acm)
{
	int minor;

	mutex_lock(&acm_table_lock);
	for (minor = 0; minor < ACM_TTY_MINORS; minor++) {
		if (!acm_table[minor]) {
			acm_table[minor] = acm;
			break;
		}
	}
	mutex_unlock(&acm_table_lock);

	return minor;
}

/* Release the minor number associated with 'acm'.  */
static void acm_release_minor(struct acm *acm)
{
	mutex_lock(&acm_table_lock);
	acm_table[acm->minor] = NULL;
	mutex_unlock(&acm_table_lock);
}

/*
 * Functions for ACM control messages.
 */

static int acm_ctrl_msg(struct acm *acm, int request, int value,
							void *buf, int len)
{
	int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
		request, USB_RT_ACM, value,
		acm->control->altsetting[0].desc.bInterfaceNumber,
		buf, len, 5000);
	dev_dbg(&acm->control->dev,
			"%s - rq 0x%02x, val %#x, len %#x, result %d\n",
			__func__, request, value, len, retval);
	return retval < 0 ? retval : 0;
}

/* devices aren't required to support these requests.
 * the cdc acm descriptor tells whether they do...
 */
#define acm_set_control(acm, control) \
	acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
#define acm_set_line(acm, line) \
	acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
#define acm_send_break(acm, ms) \
	acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)

/*
 * Write buffer management.
 * All of these assume proper locks taken by the caller.
 */

static int acm_wb_alloc(struct acm *acm)
{
	int i, wbn;
	struct acm_wb *wb;

	wbn = 0;
	i = 0;
	for (;;) {
		wb = &acm->wb[wbn];
		if (!wb->use) {
			wb->use = 1;
			return wbn;
		}
		wbn = (wbn + 1) % ACM_NW;
		if (++i >= ACM_NW)
			return -1;
	}
}

static int acm_wb_is_avail(struct acm *acm)
{
	int i, n;
	unsigned long flags;

	n = ACM_NW;
	spin_lock_irqsave(&acm->write_lock, flags);
	for (i = 0; i < ACM_NW; i++)
		n -= acm->wb[i].use;
	spin_unlock_irqrestore(&acm->write_lock, flags);
	return n;
}

/*
 * Finish write. Caller must hold acm->write_lock
 */
static void acm_write_done(struct acm *acm, struct acm_wb *wb)
{
	wb->use = 0;
	acm->transmitting--;
	usb_autopm_put_interface_async(acm->control);
}

/*
 * Poke write.
 *
 * the caller is responsible for locking
 */

static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
{
	int rc;

	acm->transmitting++;

	wb->urb->transfer_buffer = wb->buf;
	wb->urb->transfer_dma = wb->dmah;
	wb->urb->transfer_buffer_length = wb->len;
	wb->urb->dev = acm->dev;

	rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
	if (rc < 0) {
		dev_err(&acm->data->dev,
			"%s - usb_submit_urb(write bulk) failed: %d\n",
			__func__, rc);
		acm_write_done(acm, wb);
	}
	return rc;
}

static int acm_write_start(struct acm *acm, int wbn)
{
	unsigned long flags;
	struct acm_wb *wb = &acm->wb[wbn];
	int rc;

	spin_lock_irqsave(&acm->write_lock, flags);
	if (!acm->dev) {
		wb->use = 0;
		spin_unlock_irqrestore(&acm->write_lock, flags);
		return -ENODEV;
	}

	dev_vdbg(&acm->data->dev, "%s - susp_count %d\n", __func__,
							acm->susp_count);
	usb_autopm_get_interface_async(acm->control);
	if (acm->susp_count) {
		if (!acm->delayed_wb)
			acm->delayed_wb = wb;
		else
			usb_autopm_put_interface_async(acm->control);
		spin_unlock_irqrestore(&acm->write_lock, flags);
		return 0;	/* A white lie */
	}
	usb_mark_last_busy(acm->dev);

	rc = acm_start_wb(acm, wb);
	spin_unlock_irqrestore(&acm->write_lock, flags);

	return rc;

}
/*
 * attributes exported through sysfs
 */
static ssize_t show_caps
(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct acm *acm = usb_get_intfdata(intf);

	return sprintf(buf, "%d", acm->ctrl_caps);
}
static DEVICE_ATTR(bmCapabilities, S_IRUGO, show_caps, NULL);

static ssize_t show_country_codes
(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct acm *acm = usb_get_intfdata(intf);

	memcpy(buf, acm->country_codes, acm->country_code_size);
	return acm->country_code_size;
}

static DEVICE_ATTR(wCountryCodes, S_IRUGO, show_country_codes, NULL);

static ssize_t show_country_rel_date
(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct acm *acm = usb_get_intfdata(intf);

	return sprintf(buf, "%d", acm->country_rel_date);
}

static DEVICE_ATTR(iCountryCodeRelDate, S_IRUGO, show_country_rel_date, NULL);
/*
 * Interrupt handlers for various ACM device responses
 */

/* control interface reports status changes with "interrupt" transfers */
static void acm_ctrl_irq(struct urb *urb)
{
	struct acm *acm = urb->context;
	struct usb_cdc_notification *dr = urb->transfer_buffer;
	struct tty_struct *tty;
	unsigned char *data;
	int newctrl;
	int retval;
	int status = urb->status;

	switch (status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dev_dbg(&acm->control->dev,
				"%s - urb shutting down with status: %d\n",
				__func__, status);
		return;
	default:
		dev_dbg(&acm->control->dev,
				"%s - nonzero urb status received: %d\n",
				__func__, status);
		goto exit;
	}

	usb_mark_last_busy(acm->dev);

	data = (unsigned char *)(dr + 1);
	switch (dr->bNotificationType) {
	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
		dev_dbg(&acm->control->dev, "%s - network connection: %d\n",
							__func__, dr->wValue);
		break;

	case USB_CDC_NOTIFY_SERIAL_STATE:
		tty = tty_port_tty_get(&acm->port);
		newctrl = get_unaligned_le16(data);

		if (tty) {
			if (!acm->clocal &&
				(acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
				dev_dbg(&acm->control->dev,
					"%s - calling hangup\n", __func__);
				tty_hangup(tty);
			}
			tty_kref_put(tty);
		}

		acm->ctrlin = newctrl;

		dev_dbg(&acm->control->dev,
			"%s - input control lines: dcd%c dsr%c break%c "
			"ring%c framing%c parity%c overrun%c\n",
			__func__,
			acm->ctrlin & ACM_CTRL_DCD ? '+' : '-',
			acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
			acm->ctrlin & ACM_CTRL_BRK ? '+' : '-',
			acm->ctrlin & ACM_CTRL_RI  ? '+' : '-',
			acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',
			acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
			acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
			break;

	default:
		dev_dbg(&acm->control->dev,
			"%s - unknown notification %d received: index %d "
			"len %d data0 %d data1 %d\n",
			__func__,
			dr->bNotificationType, dr->wIndex,
			dr->wLength, data[0], data[1]);
		break;
	}
exit:
	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval)
		dev_err(&acm->control->dev, "%s - usb_submit_urb failed: %d\n",
							__func__, retval);
}

static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
{
	int res;

	if (!test_and_clear_bit(index, &acm->read_urbs_free))
		return 0;

	dev_vdbg(&acm->data->dev, "%s - urb %d\n", __func__, index);

	res = usb_submit_urb(acm->read_urbs[index], mem_flags);
	if (res) {
		if (res != -EPERM) {
			dev_err(&acm->data->dev,
					"%s - usb_submit_urb failed: %d\n",
					__func__, res);
		}
		set_bit(index, &acm->read_urbs_free);
		return res;
	}

	return 0;
}

static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
{
	int res;
	int i;

	for (i = 0; i < acm->rx_buflimit; ++i) {
		res = acm_submit_read_urb(acm, i, mem_flags);
		if (res)
			return res;
	}

	return 0;
}

static void acm_process_read_urb(struct acm *acm, struct urb *urb)
{
	struct tty_struct *tty;

	if (!urb->actual_length)
		return;

	tty = tty_port_tty_get(&acm->port);
	if (!tty)
		return;

	tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
	tty_flip_buffer_push(tty);

	tty_kref_put(tty);
}

static void acm_read_bulk_callback(struct urb *urb)
{
	struct acm_rb *rb = urb->context;
	struct acm *acm = rb->instance;
	unsigned long flags;

	dev_vdbg(&acm->data->dev, "%s - urb %d, len %d\n", __func__,
					rb->index, urb->actual_length);
	set_bit(rb->index, &acm->read_urbs_free);

	if (!acm->dev) {
		dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
		return;
	}
	usb_mark_last_busy(acm->dev);

	if (urb->status) {
		dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
							__func__, urb->status);
		return;
	}
	acm_process_read_urb(acm, urb);

	/* throttle device if requested by tty */
	spin_lock_irqsave(&acm->read_lock, flags);
	acm->throttled = acm->throttle_req;
	if (!acm->throttled && !acm->susp_count) {
		spin_unlock_irqrestore(&acm->read_lock, flags);
		acm_submit_read_urb(acm, rb->index, GFP_ATOMIC);
	} else {
		spin_unlock_irqrestore(&acm->read_lock, flags);
	}
}

/* data interface wrote those outgoing bytes */
static void acm_write_bulk(struct urb *urb)
{
	struct acm_wb *wb = urb->context;
	struct acm *acm = wb->instance;
	unsigned long flags;

	if (urb->status	|| (urb->actual_length != urb->transfer_buffer_length))
		dev_vdbg(&acm->data->dev, "%s - len %d/%d, status %d\n",
			__func__,
			urb->actual_length,
			urb->transfer_buffer_length,
			urb->status);

	spin_lock_irqsave(&acm->write_lock, flags);
	acm_write_done(acm, wb);
	spin_unlock_irqrestore(&acm->write_lock, flags);
	schedule_work(&acm->work);
}

static void acm_softint(struct work_struct *work)
{
	struct acm *acm = container_of(work, struct acm, work);
	struct tty_struct *tty;

	dev_vdbg(&acm->data->dev, "%s\n", __func__);

	tty = tty_port_tty_get(&acm->port);
	if (!tty)
		return;
	tty_wakeup(tty);
	tty_kref_put(tty);
}

/*
 * TTY handlers
 */

static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
{
	struct acm *acm;
	int retval;

	dev_dbg(tty->dev, "%s\n", __func__);

	acm = acm_get_by_index(tty->index);
	if (!acm)
		return -ENODEV;

	retval = tty_init_termios(tty);
	if (retval)
		goto error_init_termios;

	tty->driver_data = acm;

	/* Final install (we use the default method) */
	tty_driver_kref_get(driver);
	tty->count++;
	driver->ttys[tty->index] = tty;

	return 0;

error_init_termios:
	tty_port_put(&acm->port);
	return retval;
}

static int acm_tty_open(struct tty_struct *tty, struct file *filp)
{
	struct acm *acm = tty->driver_data;

	dev_dbg(tty->dev, "%s\n", __func__);

	return tty_port_open(&acm->port, tty, filp);
}

static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
{
	struct acm *acm = container_of(port, struct acm, port);
	int retval = -ENODEV;

	dev_dbg(&acm->control->dev, "%s\n", __func__);

	mutex_lock(&acm->mutex);
	if (acm->disconnected)
		goto disconnected;

	retval = usb_autopm_get_interface(acm->control);
	if (retval)
		goto error_get_interface;

	/*
	 * FIXME: Why do we need this? Allocating 64K of physically contiguous
	 * memory is really nasty...
	 */
	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
	acm->control->needs_remote_wakeup = 1;

	acm->ctrlurb->dev = acm->dev;
	if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
		dev_err(&acm->control->dev,
			"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
		goto error_submit_urb;
	}

	acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
	if (acm_set_control(acm, acm->ctrlout) < 0 &&
	    (acm->ctrl_caps & USB_CDC_CAP_LINE))
		goto error_set_control;

	usb_autopm_put_interface(acm->control);

	if (acm_submit_read_urbs(acm, GFP_KERNEL))
		goto error_submit_read_urbs;

	mutex_unlock(&acm->mutex);

	return 0;

error_submit_read_urbs:
	acm->ctrlout = 0;
	acm_set_control(acm, acm->ctrlout);
error_set_control:
	usb_kill_urb(acm->ctrlurb);
error_submit_urb:
	usb_autopm_put_interface(acm->control);
error_get_interface:
disconnected:
	mutex_unlock(&acm->mutex);
	return retval;
}

static void acm_port_destruct(struct tty_port *port)
{
	struct acm *acm = container_of(port, struct acm, port);

	dev_dbg(&acm->control->dev, "%s\n", __func__);

	tty_unregister_device(acm_tty_driver, acm->minor);
	acm_release_minor(acm);
	usb_put_intf(acm->control);
	kfree(acm->country_codes);
	kfree(acm);
}

static void acm_port_shutdown(struct tty_port *port)
{
	struct acm *acm = container_of(port, struct acm, port);
	int i;

	dev_dbg(&acm->control->dev, "%s\n", __func__);

	mutex_lock(&acm->mutex);
	if (!acm->disconnected) {
		usb_autopm_get_interface(acm->control);
		acm_set_control(acm, acm->ctrlout = 0);
		usb_kill_urb(acm->ctrlurb);
		for (i = 0; i < ACM_NW; i++)
			usb_kill_urb(acm->wb[i].urb);
		for (i = 0; i < acm->rx_buflimit; i++)
			usb_kill_urb(acm->read_urbs[i]);
		acm->control->needs_remote_wakeup = 0;
		usb_autopm_put_interface(acm->control);
	}
	mutex_unlock(&acm->mutex);
}

static void acm_tty_cleanup(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	dev_dbg(&acm->control->dev, "%s\n", __func__);
	tty_port_put(&acm->port);
}

static void acm_tty_hangup(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	dev_dbg(&acm->control->dev, "%s\n", __func__);
	tty_port_hangup(&acm->port);
}

static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
	struct acm *acm = tty->driver_data;
	dev_dbg(&acm->control->dev, "%s\n", __func__);
	tty_port_close(&acm->port, tty, filp);
}

static int acm_tty_write(struct tty_struct *tty,
					const unsigned char *buf, int count)
{
	struct acm *acm = tty->driver_data;
	int stat;
	unsigned long flags;
	int wbn;
	struct acm_wb *wb;

	if (!count)
		return 0;

	dev_vdbg(&acm->data->dev, "%s - count %d\n", __func__, count);

	spin_lock_irqsave(&acm->write_lock, flags);
	wbn = acm_wb_alloc(acm);
	if (wbn < 0) {
		spin_unlock_irqrestore(&acm->write_lock, flags);
		return 0;
	}
	wb = &acm->wb[wbn];

	count = (count > acm->writesize) ? acm->writesize : count;
	dev_vdbg(&acm->data->dev, "%s - write %d\n", __func__, count);
	memcpy(wb->buf, buf, count);
	wb->len = count;
	spin_unlock_irqrestore(&acm->write_lock, flags);

	stat = acm_write_start(acm, wbn);
	if (stat < 0)
		return stat;
	return count;
}

static int acm_tty_write_room(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	/*
	 * Do not let the line discipline to know that we have a reserve,
	 * or it might get too enthusiastic.
	 */
	return acm_wb_is_avail(acm) ? acm->writesize : 0;
}

static int acm_tty_chars_in_buffer(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	/*
	 * if the device was unplugged then any remaining characters fell out
	 * of the connector ;)
	 */
	if (acm->disconnected)
		return 0;
	/*
	 * This is inaccurate (overcounts), but it works.
	 */
	return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
}

static void acm_tty_throttle(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;

	spin_lock_irq(&acm->read_lock);
	acm->throttle_req = 1;
	spin_unlock_irq(&acm->read_lock);
}

static void acm_tty_unthrottle(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;
	unsigned int was_throttled;

	spin_lock_irq(&acm->read_lock);
	was_throttled = acm->throttled;
	acm->throttled = 0;
	acm->throttle_req = 0;
	spin_unlock_irq(&acm->read_lock);

	if (was_throttled)
		acm_submit_read_urbs(acm, GFP_KERNEL);
}

static int acm_tty_break_ctl(struct tty_struct *tty, int state)
{
	struct acm *acm = tty->driver_data;
	int retval;

	retval = acm_send_break(acm, state ? 0xffff : 0);
	if (retval < 0)
		dev_dbg(&acm->control->dev, "%s - send break failed\n",
								__func__);
	return retval;
}

static int acm_tty_tiocmget(struct tty_struct *tty)
{
	struct acm *acm = tty->driver_data;

	return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
	       (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
	       (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
	       (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
	       (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
	       TIOCM_CTS;
}

static int acm_tty_tiocmset(struct tty_struct *tty,
			    unsigned int set, unsigned int clear)
{
	struct acm *acm = tty->driver_data;
	unsigned int newctrl;

	newctrl = acm->ctrlout;
	set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
					(set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
	clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
					(clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);

	newctrl = (newctrl & ~clear) | set;

	if (acm->ctrlout == newctrl)
		return 0;
	return acm_set_control(acm, acm->ctrlout = newctrl);
}

static int acm_tty_ioctl(struct tty_struct *tty,
					unsigned int cmd, unsigned long arg)
{
	return -ENOIOCTLCMD;
}

static const __u32 acm_tty_speed[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600,
	1200, 1800, 2400, 4800, 9600, 19200, 38400,
	57600, 115200, 230400, 460800, 500000, 576000,
	921600, 1000000, 1152000, 1500000, 2000000,
	2500000, 3000000, 3500000, 4000000
};

static const __u8 acm_tty_size[] = {
	5, 6, 7, 8
};

static void acm_tty_set_termios(struct tty_struct *tty,
						struct ktermios *termios_old)
{
	struct acm *acm = tty->driver_data;
	struct ktermios *termios = tty->termios;
	struct usb_cdc_line_coding newline;
	int newctrl = acm->ctrlout;

	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
	newline.bParityType = termios->c_cflag & PARENB ?
				(termios->c_cflag & PARODD ? 1 : 2) +
				(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
	newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
	/* FIXME: Needs to clear unsupported bits in the termios */
	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);

	if (!newline.dwDTERate) {
		newline.dwDTERate = acm->line.dwDTERate;
		newctrl &= ~ACM_CTRL_DTR;
	} else
		newctrl |=  ACM_CTRL_DTR;

	if (newctrl != acm->ctrlout)
		acm_set_control(acm, acm->ctrlout = newctrl);

	if (memcmp(&acm->line, &newline, sizeof newline)) {
		memcpy(&acm->line, &newline, sizeof newline);
		dev_dbg(&acm->control->dev, "%s - set line: %d %d %d %d\n",
			__func__,
			le32_to_cpu(newline.dwDTERate),
			newline.bCharFormat, newline.bParityType,
			newline.bDataBits);
		acm_set_line(acm, &acm->line);
	}
}

static const struct tty_port_operations acm_port_ops = {
	.shutdown = acm_port_shutdown,
	.activate = acm_port_activate,
	.destruct = acm_port_destruct,
};

/*
 * USB probe and disconnect routines.
 */

/* Little helpers: write/read buffers free */
static void acm_write_buffers_free(struct acm *acm)
{
	int i;
	struct acm_wb *wb;
	struct usb_device *usb_dev = interface_to_usbdev(acm->control);

	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++)
		usb_free_coherent(usb_dev, acm->writesize, wb->buf, wb->dmah);
}

static void acm_read_buffers_free(struct acm *acm)
{
	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
	int i;

	for (i = 0; i < acm->rx_buflimit; i++)
		usb_free_coherent(usb_dev, acm->readsize,
			  acm->read_buffers[i].base, acm->read_buffers[i].dma);
}

/* Little helper: write buffers allocate */
static int acm_write_buffers_alloc(struct acm *acm)
{
	int i;
	struct acm_wb *wb;

	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
		wb->buf = usb_alloc_coherent(acm->dev, acm->writesize, GFP_KERNEL,
		    &wb->dmah);
		if (!wb->buf) {
			while (i != 0) {
				--i;
				--wb;
				usb_free_coherent(acm->dev, acm->writesize,
				    wb->buf, wb->dmah);
			}
			return -ENOMEM;
		}
	}
	return 0;
}

static int acm_probe(struct usb_interface *intf,
		     const struct usb_device_id *id)
{
	struct usb_cdc_union_desc *union_header = NULL;
	struct usb_cdc_country_functional_desc *cfd = NULL;
	unsigned char *buffer = intf->altsetting->extra;
	int buflen = intf->altsetting->extralen;
	struct usb_interface *control_interface;
	struct usb_interface *data_interface;
	struct usb_endpoint_descriptor *epctrl = NULL;
	struct usb_endpoint_descriptor *epread = NULL;
	struct usb_endpoint_descriptor *epwrite = NULL;
	struct usb_device *usb_dev = interface_to_usbdev(intf);
	struct acm *acm;
	int minor;
	int ctrlsize, readsize;
	u8 *buf;
	u8 ac_management_function = 0;
	u8 call_management_function = 0;
	int call_interface_num = -1;
	int data_interface_num = -1;
	unsigned long quirks;
	int num_rx_buf;
	int i;
	int combined_interfaces = 0;

	/* normal quirks */
	quirks = (unsigned long)id->driver_info;
	num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;

	/* handle quirks deadly to normal probing*/
	if (quirks == NO_UNION_NORMAL) {
		data_interface = usb_ifnum_to_if(usb_dev, 1);
		control_interface = usb_ifnum_to_if(usb_dev, 0);
		goto skip_normal_probe;
	}

	/* normal probing*/
	if (!buffer) {
		dev_err(&intf->dev, "Weird descriptor references\n");
		return -EINVAL;
	}

	if (!buflen) {
		if (intf->cur_altsetting->endpoint &&
				intf->cur_altsetting->endpoint->extralen &&
				intf->cur_altsetting->endpoint->extra) {
			dev_dbg(&intf->dev,
				"Seeking extra descriptors on endpoint\n");
			buflen = intf->cur_altsetting->endpoint->extralen;
			buffer = intf->cur_altsetting->endpoint->extra;
		} else {
			dev_err(&intf->dev,
				"Zero length descriptor references\n");
			return -EINVAL;
		}
	}

	while (buflen > 0) {
		if (buffer[1] != USB_DT_CS_INTERFACE) {
			dev_err(&intf->dev, "skipping garbage\n");
			goto next_desc;
		}

		switch (buffer[2]) {
		case USB_CDC_UNION_TYPE: /* we've found it */
			if (union_header) {
				dev_err(&intf->dev, "More than one "
					"union descriptor, skipping ...\n");
				goto next_desc;
			}
			union_header = (struct usb_cdc_union_desc *)buffer;
			break;
		case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
			cfd = (struct usb_cdc_country_functional_desc *)buffer;
			break;
		case USB_CDC_HEADER_TYPE: /* maybe check version */
			break; /* for now we ignore it */
		case USB_CDC_ACM_TYPE:
			ac_management_function = buffer[3];
			break;
		case USB_CDC_CALL_MANAGEMENT_TYPE:
			call_management_function = buffer[3];
			call_interface_num = buffer[4];
			if ( (quirks & NOT_A_MODEM) == 0 && (call_management_function & 3) != 3)
				dev_err(&intf->dev, "This device cannot do calls on its own. It is not a modem.\n");
			break;
		default:
			/* there are LOTS more CDC descriptors that
			 * could legitimately be found here.
			 */
			dev_dbg(&intf->dev, "Ignoring descriptor: "
					"type %02x, length %d\n",
					buffer[2], buffer[0]);
			break;
		}
next_desc:
		buflen -= buffer[0];
		buffer += buffer[0];
	}

	if (!union_header) {
		if (call_interface_num > 0) {
			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
			/* quirks for Droids MuIn LCD */
			if (quirks & NO_DATA_INTERFACE)
				data_interface = usb_ifnum_to_if(usb_dev, 0);
			else
				data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
			control_interface = intf;
		} else {
			if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
				dev_dbg(&intf->dev,"No union descriptor, giving up\n");
				return -ENODEV;
			} else {
				dev_warn(&intf->dev,"No union descriptor, testing for castrated device\n");
				combined_interfaces = 1;
				control_interface = data_interface = intf;
				goto look_for_collapsed_interface;
			}
		}
	} else {
		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
		data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
		if (!control_interface || !data_interface) {
			dev_dbg(&intf->dev, "no interfaces\n");
			return -ENODEV;
		}
	}

	if (data_interface_num != call_interface_num)
		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");

	if (control_interface == data_interface) {
		/* some broken devices designed for windows work this way */
		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");
		combined_interfaces = 1;
		/* a popular other OS doesn't use it */
		quirks |= NO_CAP_LINE;
		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {
			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");
			return -EINVAL;
		}
look_for_collapsed_interface:
		for (i = 0; i < 3; i++) {
			struct usb_endpoint_descriptor *ep;
			ep = &data_interface->cur_altsetting->endpoint[i].desc;

			if (usb_endpoint_is_int_in(ep))
				epctrl = ep;
			else if (usb_endpoint_is_bulk_out(ep))
				epwrite = ep;
			else if (usb_endpoint_is_bulk_in(ep))
				epread = ep;
			else
				return -EINVAL;
		}
		if (!epctrl || !epread || !epwrite)
			return -ENODEV;
		else
			goto made_compressed_probe;
	}

skip_normal_probe:

	/*workaround for switched interfaces */
	if (data_interface->cur_altsetting->desc.bInterfaceClass
						!= CDC_DATA_INTERFACE_TYPE) {
		if (control_interface->cur_altsetting->desc.bInterfaceClass
						== CDC_DATA_INTERFACE_TYPE) {
			struct usb_interface *t;
			dev_dbg(&intf->dev,
				"Your device has switched interfaces.\n");
			t = control_interface;
			control_interface = data_interface;
			data_interface = t;
		} else {
			return -EINVAL;
		}
	}

	/* Accept probe requests only for the control interface */
	if (!combined_interfaces && intf != control_interface)
		return -ENODEV;

	if (!combined_interfaces && usb_interface_claimed(data_interface)) {
		/* valid in this context */
		dev_dbg(&intf->dev, "The data interface isn't available\n");
		return -EBUSY;
	}


	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
		return -EINVAL;

	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
	epread = &data_interface->cur_altsetting->endpoint[0].desc;
	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;


	/* workaround for switched endpoints */
	if (!usb_endpoint_dir_in(epread)) {
		/* descriptors are swapped */
		struct usb_endpoint_descriptor *t;
		dev_dbg(&intf->dev,
			"The data interface has switched endpoints\n");
		t = epread;
		epread = epwrite;
		epwrite = t;
	}
made_compressed_probe:
	dev_dbg(&intf->dev, "interfaces are valid\n");

	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
	if (acm == NULL) {
		dev_err(&intf->dev, "out of memory (acm kzalloc)\n");
		goto alloc_fail;
	}

	minor = acm_alloc_minor(acm);
	if (minor == ACM_TTY_MINORS) {
		dev_err(&intf->dev, "no more free acm devices\n");
		kfree(acm);
		return -ENODEV;
	}

	ctrlsize = usb_endpoint_maxp(epctrl);
	readsize = usb_endpoint_maxp(epread) *
				(quirks == SINGLE_RX_URB ? 1 : 2);
	acm->combined_interfaces = combined_interfaces;
	acm->writesize = usb_endpoint_maxp(epwrite) * 20;
	acm->control = control_interface;
	acm->data = data_interface;
	acm->minor = minor;
	acm->dev = usb_dev;
	acm->ctrl_caps = ac_management_function;
	if (quirks & NO_CAP_LINE)
		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
	acm->ctrlsize = ctrlsize;
	acm->readsize = readsize;
	acm->rx_buflimit = num_rx_buf;
	INIT_WORK(&acm->work, acm_softint);
	spin_lock_init(&acm->write_lock);
	spin_lock_init(&acm->read_lock);
	mutex_init(&acm->mutex);
	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
	acm->is_int_ep = usb_endpoint_xfer_int(epread);
	if (acm->is_int_ep)
		acm->bInterval = epread->bInterval;
	tty_port_init(&acm->port);
	acm->port.ops = &acm_port_ops;

	buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
	if (!buf) {
		dev_err(&intf->dev, "out of memory (ctrl buffer alloc)\n");
		goto alloc_fail2;
	}
	acm->ctrl_buffer = buf;

	if (acm_write_buffers_alloc(acm) < 0) {
		dev_err(&intf->dev, "out of memory (write buffer alloc)\n");
		goto alloc_fail4;
	}

	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
	if (!acm->ctrlurb) {
		dev_err(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
		goto alloc_fail5;
	}
	for (i = 0; i < num_rx_buf; i++) {
		struct acm_rb *rb = &(acm->read_buffers[i]);
		struct urb *urb;

		rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
								&rb->dma);
		if (!rb->base) {
			dev_err(&intf->dev, "out of memory "
					"(read bufs usb_alloc_coherent)\n");
			goto alloc_fail6;
		}
		rb->index = i;
		rb->instance = acm;

		urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!urb) {
			dev_err(&intf->dev,
				"out of memory (read urbs usb_alloc_urb)\n");
			goto alloc_fail6;
		}
		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		urb->transfer_dma = rb->dma;
		if (acm->is_int_ep) {
			usb_fill_int_urb(urb, acm->dev,
					 acm->rx_endpoint,
					 rb->base,
					 acm->readsize,
					 acm_read_bulk_callback, rb,
					 acm->bInterval);
		} else {
			usb_fill_bulk_urb(urb, acm->dev,
					  acm->rx_endpoint,
					  rb->base,
					  acm->readsize,
					  acm_read_bulk_callback, rb);
		}

		acm->read_urbs[i] = urb;
		__set_bit(i, &acm->read_urbs_free);
	}
	for (i = 0; i < ACM_NW; i++) {
		struct acm_wb *snd = &(acm->wb[i]);

		snd->urb = usb_alloc_urb(0, GFP_KERNEL);
		if (snd->urb == NULL) {
			dev_err(&intf->dev,
				"out of memory (write urbs usb_alloc_urb)\n");
			goto alloc_fail7;
		}

		if (usb_endpoint_xfer_int(epwrite))
			usb_fill_int_urb(snd->urb, usb_dev,
				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
		else
			usb_fill_bulk_urb(snd->urb, usb_dev,
				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
				NULL, acm->writesize, acm_write_bulk, snd);
		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		snd->instance = acm;
	}

	usb_set_intfdata(intf, acm);

	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
	if (i < 0)
		goto alloc_fail7;

	if (cfd) { /* export the country data */
		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
		if (!acm->country_codes)
			goto skip_countries;
		acm->country_code_size = cfd->bLength - 4;
		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0,
							cfd->bLength - 4);
		acm->country_rel_date = cfd->iCountryCodeRelDate;

		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
		if (i < 0) {
			kfree(acm->country_codes);
			acm->country_codes = NULL;
			acm->country_code_size = 0;
			goto skip_countries;
		}

		i = device_create_file(&intf->dev,
						&dev_attr_iCountryCodeRelDate);
		if (i < 0) {
			device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
			kfree(acm->country_codes);
			acm->country_codes = NULL;
			acm->country_code_size = 0;
			goto skip_countries;
		}
	}

skip_countries:
	usb_fill_int_urb(acm->ctrlurb, usb_dev,
			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,
			 /* works around buggy devices */
			 epctrl->bInterval ? epctrl->bInterval : 0xff);
	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	acm->ctrlurb->transfer_dma = acm->ctrl_dma;

	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);

	acm_set_control(acm, acm->ctrlout);

	acm->line.dwDTERate = cpu_to_le32(9600);
	acm->line.bDataBits = 8;
	acm_set_line(acm, &acm->line);

	usb_driver_claim_interface(&acm_driver, data_interface, acm);
	usb_set_intfdata(data_interface, acm);

	usb_get_intf(control_interface);
	tty_register_device(acm_tty_driver, minor, &control_interface->dev);

	return 0;
alloc_fail7:
	for (i = 0; i < ACM_NW; i++)
		usb_free_urb(acm->wb[i].urb);
alloc_fail6:
	for (i = 0; i < num_rx_buf; i++)
		usb_free_urb(acm->read_urbs[i]);
	acm_read_buffers_free(acm);
	usb_free_urb(acm->ctrlurb);
alloc_fail5:
	acm_write_buffers_free(acm);
alloc_fail4:
	usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
alloc_fail2:
	acm_release_minor(acm);
	kfree(acm);
alloc_fail:
	return -ENOMEM;
}

static void stop_data_traffic(struct acm *acm)
{
	int i;

	dev_dbg(&acm->control->dev, "%s\n", __func__);

	usb_kill_urb(acm->ctrlurb);
	for (i = 0; i < ACM_NW; i++)
		usb_kill_urb(acm->wb[i].urb);
	for (i = 0; i < acm->rx_buflimit; i++)
		usb_kill_urb(acm->read_urbs[i]);

	cancel_work_sync(&acm->work);
}

static void acm_disconnect(struct usb_interface *intf)
{
	struct acm *acm = usb_get_intfdata(intf);
	struct usb_device *usb_dev = interface_to_usbdev(intf);
	struct tty_struct *tty;
	int i;

	dev_dbg(&intf->dev, "%s\n", __func__);

	/* sibling interface is already cleaning up */
	if (!acm)
		return;

	mutex_lock(&acm->mutex);
	acm->disconnected = true;
	if (acm->country_codes) {
		device_remove_file(&acm->control->dev,
				&dev_attr_wCountryCodes);
		device_remove_file(&acm->control->dev,
				&dev_attr_iCountryCodeRelDate);
	}
	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
	usb_set_intfdata(acm->control, NULL);
	usb_set_intfdata(acm->data, NULL);
	mutex_unlock(&acm->mutex);

	tty = tty_port_tty_get(&acm->port);
	if (tty) {
		tty_vhangup(tty);
		tty_kref_put(tty);
	}

	stop_data_traffic(acm);

	usb_free_urb(acm->ctrlurb);
	for (i = 0; i < ACM_NW; i++)
		usb_free_urb(acm->wb[i].urb);
	for (i = 0; i < acm->rx_buflimit; i++)
		usb_free_urb(acm->read_urbs[i]);
	acm_write_buffers_free(acm);
	usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
	acm_read_buffers_free(acm);

	if (!acm->combined_interfaces)
		usb_driver_release_interface(&acm_driver, intf == acm->control ?
					acm->data : acm->control);

	tty_port_put(&acm->port);
}

#ifdef CONFIG_PM
static int acm_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct acm *acm = usb_get_intfdata(intf);
	int cnt;

	if (PMSG_IS_AUTO(message)) {
		int b;

		spin_lock_irq(&acm->write_lock);
		b = acm->transmitting;
		spin_unlock_irq(&acm->write_lock);
		if (b)
			return -EBUSY;
	}

	spin_lock_irq(&acm->read_lock);
	spin_lock(&acm->write_lock);
	cnt = acm->susp_count++;
	spin_unlock(&acm->write_lock);
	spin_unlock_irq(&acm->read_lock);

	if (cnt)
		return 0;

	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
		stop_data_traffic(acm);

	return 0;
}

static int acm_resume(struct usb_interface *intf)
{
	struct acm *acm = usb_get_intfdata(intf);
	struct acm_wb *wb;
	int rv = 0;
	int cnt;

	spin_lock_irq(&acm->read_lock);
	acm->susp_count -= 1;
	cnt = acm->susp_count;
	spin_unlock_irq(&acm->read_lock);

	if (cnt)
		return 0;

	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);

		spin_lock_irq(&acm->write_lock);
		if (acm->delayed_wb) {
			wb = acm->delayed_wb;
			acm->delayed_wb = NULL;
			spin_unlock_irq(&acm->write_lock);
			acm_start_wb(acm, wb);
		} else {
			spin_unlock_irq(&acm->write_lock);
		}

		/*
		 * delayed error checking because we must
		 * do the write path at all cost
		 */
		if (rv < 0)
			goto err_out;

		rv = acm_submit_read_urbs(acm, GFP_NOIO);
	}

err_out:
	return rv;
}

static int acm_reset_resume(struct usb_interface *intf)
{
	struct acm *acm = usb_get_intfdata(intf);
	struct tty_struct *tty;

	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
		tty = tty_port_tty_get(&acm->port);
		if (tty) {
			tty_hangup(tty);
			tty_kref_put(tty);
		}
	}

	return acm_resume(intf);
}

#endif /* CONFIG_PM */

#define NOKIA_PCSUITE_ACM_INFO(x) \
		USB_DEVICE_AND_INTERFACE_INFO(0x0421, x, \
		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
		USB_CDC_ACM_PROTO_VENDOR)

#define SAMSUNG_PCSUITE_ACM_INFO(x) \
		USB_DEVICE_AND_INTERFACE_INFO(0x04e7, x, \
		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
		USB_CDC_ACM_PROTO_VENDOR)

/*
 * USB driver structure.
 */

static const struct usb_device_id acm_ids[] = {
	/* quirky and broken devices */
	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
	.driver_info = SINGLE_RX_URB,
	},
	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
	.driver_info = SINGLE_RX_URB, /* firmware bug */
	},
	{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
	.driver_info = SINGLE_RX_URB, /* firmware bug */
	},
	{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
	},
	{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
	},
	/* Motorola H24 HSPA module: */
	{ USB_DEVICE(0x22b8, 0x2d91) }, /* modem                                */
	{ USB_DEVICE(0x22b8, 0x2d92) }, /* modem           + diagnostics        */
	{ USB_DEVICE(0x22b8, 0x2d93) }, /* modem + AT port                      */
	{ USB_DEVICE(0x22b8, 0x2d95) }, /* modem + AT port + diagnostics        */
	{ USB_DEVICE(0x22b8, 0x2d96) }, /* modem                         + NMEA */
	{ USB_DEVICE(0x22b8, 0x2d97) }, /* modem           + diagnostics + NMEA */
	{ USB_DEVICE(0x22b8, 0x2d99) }, /* modem + AT port               + NMEA */
	{ USB_DEVICE(0x22b8, 0x2d9a) }, /* modem + AT port + diagnostics + NMEA */

	{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
	.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
					   data interface instead of
					   communications interface.
					   Maybe we should define a new
					   quirk for this. */
	},
	{ USB_DEVICE(0x1bbb, 0x0003), /* Alcatel OT-I650 */
	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
	},
	{ USB_DEVICE(0x1576, 0x03b1), /* Maretron USB100 */
	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
	},

	/* Nokia S60 phones expose two ACM channels. The first is
	 * a modem and is picked up by the standard AT-command
	 * information below. The second is 'vendor-specific' but
	 * is treated as a serial device at the S60 end, so we want
	 * to expose it on Linux too. */
	{ NOKIA_PCSUITE_ACM_INFO(0x042D), }, /* Nokia 3250 */
	{ NOKIA_PCSUITE_ACM_INFO(0x04D8), }, /* Nokia 5500 Sport */
	{ NOKIA_PCSUITE_ACM_INFO(0x04C9), }, /* Nokia E50 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0419), }, /* Nokia E60 */
	{ NOKIA_PCSUITE_ACM_INFO(0x044D), }, /* Nokia E61 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0001), }, /* Nokia E61i */
	{ NOKIA_PCSUITE_ACM_INFO(0x0475), }, /* Nokia E62 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0508), }, /* Nokia E65 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0418), }, /* Nokia E70 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0425), }, /* Nokia N71 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0486), }, /* Nokia N73 */
	{ NOKIA_PCSUITE_ACM_INFO(0x04DF), }, /* Nokia N75 */
	{ NOKIA_PCSUITE_ACM_INFO(0x000e), }, /* Nokia N77 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0445), }, /* Nokia N80 */
	{ NOKIA_PCSUITE_ACM_INFO(0x042F), }, /* Nokia N91 & N91 8GB */
	{ NOKIA_PCSUITE_ACM_INFO(0x048E), }, /* Nokia N92 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0420), }, /* Nokia N93 */
	{ NOKIA_PCSUITE_ACM_INFO(0x04E6), }, /* Nokia N93i  */
	{ NOKIA_PCSUITE_ACM_INFO(0x04B2), }, /* Nokia 5700 XpressMusic */
	{ NOKIA_PCSUITE_ACM_INFO(0x0134), }, /* Nokia 6110 Navigator (China) */
	{ NOKIA_PCSUITE_ACM_INFO(0x046E), }, /* Nokia 6110 Navigator */
	{ NOKIA_PCSUITE_ACM_INFO(0x002f), }, /* Nokia 6120 classic &  */
	{ NOKIA_PCSUITE_ACM_INFO(0x0088), }, /* Nokia 6121 classic */
	{ NOKIA_PCSUITE_ACM_INFO(0x00fc), }, /* Nokia 6124 classic */
	{ NOKIA_PCSUITE_ACM_INFO(0x0042), }, /* Nokia E51 */
	{ NOKIA_PCSUITE_ACM_INFO(0x00b0), }, /* Nokia E66 */
	{ NOKIA_PCSUITE_ACM_INFO(0x00ab), }, /* Nokia E71 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0481), }, /* Nokia N76 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0007), }, /* Nokia N81 & N81 8GB */
	{ NOKIA_PCSUITE_ACM_INFO(0x0071), }, /* Nokia N82 */
	{ NOKIA_PCSUITE_ACM_INFO(0x04F0), }, /* Nokia N95 & N95-3 NAM */
	{ NOKIA_PCSUITE_ACM_INFO(0x0070), }, /* Nokia N95 8GB  */
	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
	{ NOKIA_PCSUITE_ACM_INFO(0x0099), }, /* Nokia 6210 Navigator, RM-367 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0128), }, /* Nokia 6210 Navigator, RM-419 */
	{ NOKIA_PCSUITE_ACM_INFO(0x008f), }, /* Nokia 6220 Classic */
	{ NOKIA_PCSUITE_ACM_INFO(0x00a0), }, /* Nokia 6650 */
	{ NOKIA_PCSUITE_ACM_INFO(0x007b), }, /* Nokia N78 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0094), }, /* Nokia N85 */
	{ NOKIA_PCSUITE_ACM_INFO(0x003a), }, /* Nokia N96 & N96-3  */
	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
	{ NOKIA_PCSUITE_ACM_INFO(0x0108), }, /* Nokia 5320 XpressMusic 2G */
	{ NOKIA_PCSUITE_ACM_INFO(0x01f5), }, /* Nokia N97, RM-505 */
	{ NOKIA_PCSUITE_ACM_INFO(0x02e3), }, /* Nokia 5230, RM-588 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0178), }, /* Nokia E63 */
	{ NOKIA_PCSUITE_ACM_INFO(0x010e), }, /* Nokia E75 */
	{ NOKIA_PCSUITE_ACM_INFO(0x02d9), }, /* Nokia 6760 Slide */
	{ NOKIA_PCSUITE_ACM_INFO(0x01d0), }, /* Nokia E52 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0223), }, /* Nokia E72 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0275), }, /* Nokia X6 */
	{ NOKIA_PCSUITE_ACM_INFO(0x026c), }, /* Nokia N97 Mini */
	{ NOKIA_PCSUITE_ACM_INFO(0x0154), }, /* Nokia 5800 XpressMusic */
	{ NOKIA_PCSUITE_ACM_INFO(0x04ce), }, /* Nokia E90 */
	{ NOKIA_PCSUITE_ACM_INFO(0x01d4), }, /* Nokia E55 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0302), }, /* Nokia N8 */
	{ NOKIA_PCSUITE_ACM_INFO(0x0335), }, /* Nokia E7 */
	{ NOKIA_PCSUITE_ACM_INFO(0x03cd), }, /* Nokia C7 */
	{ SAMSUNG_PCSUITE_ACM_INFO(0x6651), }, /* Samsung GTi8510 (INNOV8) */

	/* Support for Owen devices */
	{ USB_DEVICE(0x03eb, 0x0030), }, /* Owen SI30 */

	/* NOTE: non-Nokia COMM/ACM/0xff is likely MSFT RNDIS... NOT a modem! */

	/* Support Lego NXT using pbLua firmware */
	{ USB_DEVICE(0x0694, 0xff00),
	.driver_info = NOT_A_MODEM,
	},

	/* Support for Droids MuIn LCD */
	{ USB_DEVICE(0x04d8, 0x000b),
	.driver_info = NO_DATA_INTERFACE,
	},

	/* control interfaces without any protocol set */
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_PROTO_NONE) },

	/* control interfaces with various AT-command sets */
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_V25TER) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_PCCA101) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_GSM) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_3G) },
	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
		USB_CDC_ACM_PROTO_AT_CDMA) },

	{ }
};

MODULE_DEVICE_TABLE(usb, acm_ids);

static struct usb_driver acm_driver = {
	.name =		"cdc_acm",
	.probe =	acm_probe,
	.disconnect =	acm_disconnect,
#ifdef CONFIG_PM
	.suspend =	acm_suspend,
	.resume =	acm_resume,
	.reset_resume =	acm_reset_resume,
#endif
	.id_table =	acm_ids,
#ifdef CONFIG_PM
	.supports_autosuspend = 1,
#endif
};

/*
 * TTY driver structures.
 */

static const struct tty_operations acm_ops = {
	.install =		acm_tty_install,
	.open =			acm_tty_open,
	.close =		acm_tty_close,
	.cleanup =		acm_tty_cleanup,
	.hangup =		acm_tty_hangup,
	.write =		acm_tty_write,
	.write_room =		acm_tty_write_room,
	.ioctl =		acm_tty_ioctl,
	.throttle =		acm_tty_throttle,
	.unthrottle =		acm_tty_unthrottle,
	.chars_in_buffer =	acm_tty_chars_in_buffer,
	.break_ctl =		acm_tty_break_ctl,
	.set_termios =		acm_tty_set_termios,
	.tiocmget =		acm_tty_tiocmget,
	.tiocmset =		acm_tty_tiocmset,
};

/*
 * Init / exit.
 */

static int __init acm_init(void)
{
	int retval;
	acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
	if (!acm_tty_driver)
		return -ENOMEM;
	acm_tty_driver->owner = THIS_MODULE,
	acm_tty_driver->driver_name = "acm",
	acm_tty_driver->name = "ttyACM",
	acm_tty_driver->major = ACM_TTY_MAJOR,
	acm_tty_driver->minor_start = 0,
	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
	acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
	acm_tty_driver->init_termios = tty_std_termios;
	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD |
								HUPCL | CLOCAL;
	tty_set_operations(acm_tty_driver, &acm_ops);

	retval = tty_register_driver(acm_tty_driver);
	if (retval) {
		put_tty_driver(acm_tty_driver);
		return retval;
	}

	retval = usb_register(&acm_driver);
	if (retval) {
		tty_unregister_driver(acm_tty_driver);
		put_tty_driver(acm_tty_driver);
		return retval;
	}

	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");

	return 0;
}

static void __exit acm_exit(void)
{
	usb_deregister(&acm_driver);
	tty_unregister_driver(acm_tty_driver);
	put_tty_driver(acm_tty_driver);
}

module_init(acm_init);
module_exit(acm_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);