1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 USB Driver layer for GSM modems 4 5 Copyright (C) 2005 Matthias Urlichs <smurf@smurf.noris.de> 6 7 Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org> 8 9 History: see the git log. 10 11 Work sponsored by: Sigos GmbH, Germany <info@sigos.de> 12 13 This driver exists because the "normal" serial driver doesn't work too well 14 with GSM modems. Issues: 15 - data loss -- one single Receive URB is not nearly enough 16 - controlling the baud rate doesn't make sense 17 */ 18 19 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>" 20 #define DRIVER_DESC "USB Driver for GSM modems" 21 22 #include <linux/kernel.h> 23 #include <linux/jiffies.h> 24 #include <linux/errno.h> 25 #include <linux/slab.h> 26 #include <linux/tty.h> 27 #include <linux/tty_flip.h> 28 #include <linux/module.h> 29 #include <linux/bitops.h> 30 #include <linux/uaccess.h> 31 #include <linux/usb.h> 32 #include <linux/usb/serial.h> 33 #include <linux/serial.h> 34 #include "usb-wwan.h" 35 36 /* 37 * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request 38 * in CDC ACM. 39 */ 40 static int usb_wwan_send_setup(struct usb_serial_port *port) 41 { 42 struct usb_serial *serial = port->serial; 43 struct usb_wwan_port_private *portdata; 44 int val = 0; 45 int ifnum; 46 int res; 47 48 portdata = usb_get_serial_port_data(port); 49 50 if (portdata->dtr_state) 51 val |= 0x01; 52 if (portdata->rts_state) 53 val |= 0x02; 54 55 ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber; 56 57 res = usb_autopm_get_interface(serial->interface); 58 if (res) 59 return res; 60 61 res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 62 0x22, 0x21, val, ifnum, NULL, 0, 63 USB_CTRL_SET_TIMEOUT); 64 65 usb_autopm_put_interface(port->serial->interface); 66 67 return res; 68 } 69 70 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on) 71 { 72 struct usb_wwan_port_private *portdata; 73 struct usb_wwan_intf_private *intfdata; 74 75 intfdata = usb_get_serial_data(port->serial); 76 77 if (!intfdata->use_send_setup) 78 return; 79 80 portdata = usb_get_serial_port_data(port); 81 /* FIXME: locking */ 82 portdata->rts_state = on; 83 portdata->dtr_state = on; 84 85 usb_wwan_send_setup(port); 86 } 87 EXPORT_SYMBOL(usb_wwan_dtr_rts); 88 89 int usb_wwan_tiocmget(struct tty_struct *tty) 90 { 91 struct usb_serial_port *port = tty->driver_data; 92 unsigned int value; 93 struct usb_wwan_port_private *portdata; 94 95 portdata = usb_get_serial_port_data(port); 96 97 value = ((portdata->rts_state) ? TIOCM_RTS : 0) | 98 ((portdata->dtr_state) ? TIOCM_DTR : 0) | 99 ((portdata->cts_state) ? TIOCM_CTS : 0) | 100 ((portdata->dsr_state) ? TIOCM_DSR : 0) | 101 ((portdata->dcd_state) ? TIOCM_CAR : 0) | 102 ((portdata->ri_state) ? TIOCM_RNG : 0); 103 104 return value; 105 } 106 EXPORT_SYMBOL(usb_wwan_tiocmget); 107 108 int usb_wwan_tiocmset(struct tty_struct *tty, 109 unsigned int set, unsigned int clear) 110 { 111 struct usb_serial_port *port = tty->driver_data; 112 struct usb_wwan_port_private *portdata; 113 struct usb_wwan_intf_private *intfdata; 114 115 portdata = usb_get_serial_port_data(port); 116 intfdata = usb_get_serial_data(port->serial); 117 118 if (!intfdata->use_send_setup) 119 return -EINVAL; 120 121 /* FIXME: what locks portdata fields ? */ 122 if (set & TIOCM_RTS) 123 portdata->rts_state = 1; 124 if (set & TIOCM_DTR) 125 portdata->dtr_state = 1; 126 127 if (clear & TIOCM_RTS) 128 portdata->rts_state = 0; 129 if (clear & TIOCM_DTR) 130 portdata->dtr_state = 0; 131 return usb_wwan_send_setup(port); 132 } 133 EXPORT_SYMBOL(usb_wwan_tiocmset); 134 135 int usb_wwan_get_serial_info(struct tty_struct *tty, 136 struct serial_struct *ss) 137 { 138 struct usb_serial_port *port = tty->driver_data; 139 140 ss->line = port->minor; 141 ss->port = port->port_number; 142 ss->baud_base = tty_get_baud_rate(port->port.tty); 143 ss->close_delay = port->port.close_delay / 10; 144 ss->closing_wait = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? 145 ASYNC_CLOSING_WAIT_NONE : 146 port->port.closing_wait / 10; 147 return 0; 148 } 149 EXPORT_SYMBOL(usb_wwan_get_serial_info); 150 151 int usb_wwan_set_serial_info(struct tty_struct *tty, 152 struct serial_struct *ss) 153 { 154 struct usb_serial_port *port = tty->driver_data; 155 unsigned int closing_wait, close_delay; 156 int retval = 0; 157 158 close_delay = ss->close_delay * 10; 159 closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 160 ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10; 161 162 mutex_lock(&port->port.mutex); 163 164 if (!capable(CAP_SYS_ADMIN)) { 165 if ((close_delay != port->port.close_delay) || 166 (closing_wait != port->port.closing_wait)) 167 retval = -EPERM; 168 else 169 retval = -EOPNOTSUPP; 170 } else { 171 port->port.close_delay = close_delay; 172 port->port.closing_wait = closing_wait; 173 } 174 175 mutex_unlock(&port->port.mutex); 176 return retval; 177 } 178 EXPORT_SYMBOL(usb_wwan_set_serial_info); 179 180 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port, 181 const unsigned char *buf, int count) 182 { 183 struct usb_wwan_port_private *portdata; 184 struct usb_wwan_intf_private *intfdata; 185 int i; 186 int left, todo; 187 struct urb *this_urb = NULL; /* spurious */ 188 int err; 189 unsigned long flags; 190 191 portdata = usb_get_serial_port_data(port); 192 intfdata = usb_get_serial_data(port->serial); 193 194 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count); 195 196 i = 0; 197 left = count; 198 for (i = 0; left > 0 && i < N_OUT_URB; i++) { 199 todo = left; 200 if (todo > OUT_BUFLEN) 201 todo = OUT_BUFLEN; 202 203 this_urb = portdata->out_urbs[i]; 204 if (test_and_set_bit(i, &portdata->out_busy)) { 205 if (time_before(jiffies, 206 portdata->tx_start_time[i] + 10 * HZ)) 207 continue; 208 usb_unlink_urb(this_urb); 209 continue; 210 } 211 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__, 212 usb_pipeendpoint(this_urb->pipe), i); 213 214 err = usb_autopm_get_interface_async(port->serial->interface); 215 if (err < 0) { 216 clear_bit(i, &portdata->out_busy); 217 break; 218 } 219 220 /* send the data */ 221 memcpy(this_urb->transfer_buffer, buf, todo); 222 this_urb->transfer_buffer_length = todo; 223 224 spin_lock_irqsave(&intfdata->susp_lock, flags); 225 if (intfdata->suspended) { 226 usb_anchor_urb(this_urb, &portdata->delayed); 227 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 228 } else { 229 intfdata->in_flight++; 230 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 231 err = usb_submit_urb(this_urb, GFP_ATOMIC); 232 if (err) { 233 dev_err(&port->dev, 234 "%s: submit urb %d failed: %d\n", 235 __func__, i, err); 236 clear_bit(i, &portdata->out_busy); 237 spin_lock_irqsave(&intfdata->susp_lock, flags); 238 intfdata->in_flight--; 239 spin_unlock_irqrestore(&intfdata->susp_lock, 240 flags); 241 usb_autopm_put_interface_async(port->serial->interface); 242 break; 243 } 244 } 245 246 portdata->tx_start_time[i] = jiffies; 247 buf += todo; 248 left -= todo; 249 } 250 251 count -= left; 252 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count); 253 return count; 254 } 255 EXPORT_SYMBOL(usb_wwan_write); 256 257 static void usb_wwan_indat_callback(struct urb *urb) 258 { 259 int err; 260 int endpoint; 261 struct usb_serial_port *port; 262 struct device *dev; 263 unsigned char *data = urb->transfer_buffer; 264 int status = urb->status; 265 266 endpoint = usb_pipeendpoint(urb->pipe); 267 port = urb->context; 268 dev = &port->dev; 269 270 if (status) { 271 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n", 272 __func__, status, endpoint); 273 } else { 274 if (urb->actual_length) { 275 tty_insert_flip_string(&port->port, data, 276 urb->actual_length); 277 tty_flip_buffer_push(&port->port); 278 } else 279 dev_dbg(dev, "%s: empty read urb received\n", __func__); 280 } 281 /* Resubmit urb so we continue receiving */ 282 err = usb_submit_urb(urb, GFP_ATOMIC); 283 if (err) { 284 if (err != -EPERM && err != -ENODEV) { 285 dev_err(dev, "%s: resubmit read urb failed. (%d)\n", 286 __func__, err); 287 /* busy also in error unless we are killed */ 288 usb_mark_last_busy(port->serial->dev); 289 } 290 } else { 291 usb_mark_last_busy(port->serial->dev); 292 } 293 } 294 295 static void usb_wwan_outdat_callback(struct urb *urb) 296 { 297 struct usb_serial_port *port; 298 struct usb_wwan_port_private *portdata; 299 struct usb_wwan_intf_private *intfdata; 300 unsigned long flags; 301 int i; 302 303 port = urb->context; 304 intfdata = usb_get_serial_data(port->serial); 305 306 usb_serial_port_softint(port); 307 usb_autopm_put_interface_async(port->serial->interface); 308 portdata = usb_get_serial_port_data(port); 309 spin_lock_irqsave(&intfdata->susp_lock, flags); 310 intfdata->in_flight--; 311 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 312 313 for (i = 0; i < N_OUT_URB; ++i) { 314 if (portdata->out_urbs[i] == urb) { 315 smp_mb__before_atomic(); 316 clear_bit(i, &portdata->out_busy); 317 break; 318 } 319 } 320 } 321 322 int usb_wwan_write_room(struct tty_struct *tty) 323 { 324 struct usb_serial_port *port = tty->driver_data; 325 struct usb_wwan_port_private *portdata; 326 int i; 327 int data_len = 0; 328 struct urb *this_urb; 329 330 portdata = usb_get_serial_port_data(port); 331 332 for (i = 0; i < N_OUT_URB; i++) { 333 this_urb = portdata->out_urbs[i]; 334 if (this_urb && !test_bit(i, &portdata->out_busy)) 335 data_len += OUT_BUFLEN; 336 } 337 338 dev_dbg(&port->dev, "%s: %d\n", __func__, data_len); 339 return data_len; 340 } 341 EXPORT_SYMBOL(usb_wwan_write_room); 342 343 int usb_wwan_chars_in_buffer(struct tty_struct *tty) 344 { 345 struct usb_serial_port *port = tty->driver_data; 346 struct usb_wwan_port_private *portdata; 347 int i; 348 int data_len = 0; 349 struct urb *this_urb; 350 351 portdata = usb_get_serial_port_data(port); 352 353 for (i = 0; i < N_OUT_URB; i++) { 354 this_urb = portdata->out_urbs[i]; 355 /* FIXME: This locking is insufficient as this_urb may 356 go unused during the test */ 357 if (this_urb && test_bit(i, &portdata->out_busy)) 358 data_len += this_urb->transfer_buffer_length; 359 } 360 dev_dbg(&port->dev, "%s: %d\n", __func__, data_len); 361 return data_len; 362 } 363 EXPORT_SYMBOL(usb_wwan_chars_in_buffer); 364 365 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port) 366 { 367 struct usb_wwan_port_private *portdata; 368 struct usb_wwan_intf_private *intfdata; 369 struct usb_serial *serial = port->serial; 370 int i, err; 371 struct urb *urb; 372 373 portdata = usb_get_serial_port_data(port); 374 intfdata = usb_get_serial_data(serial); 375 376 if (port->interrupt_in_urb) { 377 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 378 if (err) { 379 dev_err(&port->dev, "%s: submit int urb failed: %d\n", 380 __func__, err); 381 } 382 } 383 384 /* Start reading from the IN endpoint */ 385 for (i = 0; i < N_IN_URB; i++) { 386 urb = portdata->in_urbs[i]; 387 if (!urb) 388 continue; 389 err = usb_submit_urb(urb, GFP_KERNEL); 390 if (err) { 391 dev_err(&port->dev, 392 "%s: submit read urb %d failed: %d\n", 393 __func__, i, err); 394 } 395 } 396 397 spin_lock_irq(&intfdata->susp_lock); 398 if (++intfdata->open_ports == 1) 399 serial->interface->needs_remote_wakeup = 1; 400 spin_unlock_irq(&intfdata->susp_lock); 401 /* this balances a get in the generic USB serial code */ 402 usb_autopm_put_interface(serial->interface); 403 404 return 0; 405 } 406 EXPORT_SYMBOL(usb_wwan_open); 407 408 static void unbusy_queued_urb(struct urb *urb, 409 struct usb_wwan_port_private *portdata) 410 { 411 int i; 412 413 for (i = 0; i < N_OUT_URB; i++) { 414 if (urb == portdata->out_urbs[i]) { 415 clear_bit(i, &portdata->out_busy); 416 break; 417 } 418 } 419 } 420 421 void usb_wwan_close(struct usb_serial_port *port) 422 { 423 int i; 424 struct usb_serial *serial = port->serial; 425 struct usb_wwan_port_private *portdata; 426 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 427 struct urb *urb; 428 429 portdata = usb_get_serial_port_data(port); 430 431 /* 432 * Need to take susp_lock to make sure port is not already being 433 * resumed, but no need to hold it due to initialized 434 */ 435 spin_lock_irq(&intfdata->susp_lock); 436 if (--intfdata->open_ports == 0) 437 serial->interface->needs_remote_wakeup = 0; 438 spin_unlock_irq(&intfdata->susp_lock); 439 440 for (;;) { 441 urb = usb_get_from_anchor(&portdata->delayed); 442 if (!urb) 443 break; 444 unbusy_queued_urb(urb, portdata); 445 usb_autopm_put_interface_async(serial->interface); 446 } 447 448 for (i = 0; i < N_IN_URB; i++) 449 usb_kill_urb(portdata->in_urbs[i]); 450 for (i = 0; i < N_OUT_URB; i++) 451 usb_kill_urb(portdata->out_urbs[i]); 452 usb_kill_urb(port->interrupt_in_urb); 453 454 usb_autopm_get_interface_no_resume(serial->interface); 455 } 456 EXPORT_SYMBOL(usb_wwan_close); 457 458 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port, 459 int endpoint, 460 int dir, void *ctx, char *buf, int len, 461 void (*callback) (struct urb *)) 462 { 463 struct usb_serial *serial = port->serial; 464 struct urb *urb; 465 466 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */ 467 if (!urb) 468 return NULL; 469 470 usb_fill_bulk_urb(urb, serial->dev, 471 usb_sndbulkpipe(serial->dev, endpoint) | dir, 472 buf, len, callback, ctx); 473 474 return urb; 475 } 476 477 int usb_wwan_port_probe(struct usb_serial_port *port) 478 { 479 struct usb_wwan_port_private *portdata; 480 struct urb *urb; 481 u8 *buffer; 482 int i; 483 484 if (!port->bulk_in_size || !port->bulk_out_size) 485 return -ENODEV; 486 487 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL); 488 if (!portdata) 489 return -ENOMEM; 490 491 init_usb_anchor(&portdata->delayed); 492 493 for (i = 0; i < N_IN_URB; i++) { 494 buffer = (u8 *)__get_free_page(GFP_KERNEL); 495 if (!buffer) 496 goto bail_out_error; 497 portdata->in_buffer[i] = buffer; 498 499 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress, 500 USB_DIR_IN, port, 501 buffer, IN_BUFLEN, 502 usb_wwan_indat_callback); 503 portdata->in_urbs[i] = urb; 504 } 505 506 for (i = 0; i < N_OUT_URB; i++) { 507 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL); 508 if (!buffer) 509 goto bail_out_error2; 510 portdata->out_buffer[i] = buffer; 511 512 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress, 513 USB_DIR_OUT, port, 514 buffer, OUT_BUFLEN, 515 usb_wwan_outdat_callback); 516 portdata->out_urbs[i] = urb; 517 } 518 519 usb_set_serial_port_data(port, portdata); 520 521 return 0; 522 523 bail_out_error2: 524 for (i = 0; i < N_OUT_URB; i++) { 525 usb_free_urb(portdata->out_urbs[i]); 526 kfree(portdata->out_buffer[i]); 527 } 528 bail_out_error: 529 for (i = 0; i < N_IN_URB; i++) { 530 usb_free_urb(portdata->in_urbs[i]); 531 free_page((unsigned long)portdata->in_buffer[i]); 532 } 533 kfree(portdata); 534 535 return -ENOMEM; 536 } 537 EXPORT_SYMBOL_GPL(usb_wwan_port_probe); 538 539 int usb_wwan_port_remove(struct usb_serial_port *port) 540 { 541 int i; 542 struct usb_wwan_port_private *portdata; 543 544 portdata = usb_get_serial_port_data(port); 545 usb_set_serial_port_data(port, NULL); 546 547 for (i = 0; i < N_IN_URB; i++) { 548 usb_free_urb(portdata->in_urbs[i]); 549 free_page((unsigned long)portdata->in_buffer[i]); 550 } 551 for (i = 0; i < N_OUT_URB; i++) { 552 usb_free_urb(portdata->out_urbs[i]); 553 kfree(portdata->out_buffer[i]); 554 } 555 556 kfree(portdata); 557 558 return 0; 559 } 560 EXPORT_SYMBOL(usb_wwan_port_remove); 561 562 #ifdef CONFIG_PM 563 static void stop_urbs(struct usb_serial *serial) 564 { 565 int i, j; 566 struct usb_serial_port *port; 567 struct usb_wwan_port_private *portdata; 568 569 for (i = 0; i < serial->num_ports; ++i) { 570 port = serial->port[i]; 571 portdata = usb_get_serial_port_data(port); 572 if (!portdata) 573 continue; 574 for (j = 0; j < N_IN_URB; j++) 575 usb_kill_urb(portdata->in_urbs[j]); 576 for (j = 0; j < N_OUT_URB; j++) 577 usb_kill_urb(portdata->out_urbs[j]); 578 usb_kill_urb(port->interrupt_in_urb); 579 } 580 } 581 582 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) 583 { 584 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 585 586 spin_lock_irq(&intfdata->susp_lock); 587 if (PMSG_IS_AUTO(message)) { 588 if (intfdata->in_flight) { 589 spin_unlock_irq(&intfdata->susp_lock); 590 return -EBUSY; 591 } 592 } 593 intfdata->suspended = 1; 594 spin_unlock_irq(&intfdata->susp_lock); 595 596 stop_urbs(serial); 597 598 return 0; 599 } 600 EXPORT_SYMBOL(usb_wwan_suspend); 601 602 /* Caller must hold susp_lock. */ 603 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port) 604 { 605 struct usb_serial *serial = port->serial; 606 struct usb_wwan_intf_private *data = usb_get_serial_data(serial); 607 struct usb_wwan_port_private *portdata; 608 struct urb *urb; 609 int err_count = 0; 610 int err; 611 612 portdata = usb_get_serial_port_data(port); 613 614 for (;;) { 615 urb = usb_get_from_anchor(&portdata->delayed); 616 if (!urb) 617 break; 618 619 err = usb_submit_urb(urb, GFP_ATOMIC); 620 if (err) { 621 dev_err(&port->dev, "%s: submit urb failed: %d\n", 622 __func__, err); 623 err_count++; 624 unbusy_queued_urb(urb, portdata); 625 usb_autopm_put_interface_async(serial->interface); 626 continue; 627 } 628 data->in_flight++; 629 } 630 631 if (err_count) 632 return -EIO; 633 634 return 0; 635 } 636 637 int usb_wwan_resume(struct usb_serial *serial) 638 { 639 int i, j; 640 struct usb_serial_port *port; 641 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 642 struct usb_wwan_port_private *portdata; 643 struct urb *urb; 644 int err; 645 int err_count = 0; 646 647 spin_lock_irq(&intfdata->susp_lock); 648 for (i = 0; i < serial->num_ports; i++) { 649 port = serial->port[i]; 650 651 if (!tty_port_initialized(&port->port)) 652 continue; 653 654 portdata = usb_get_serial_port_data(port); 655 656 if (port->interrupt_in_urb) { 657 err = usb_submit_urb(port->interrupt_in_urb, 658 GFP_ATOMIC); 659 if (err) { 660 dev_err(&port->dev, 661 "%s: submit int urb failed: %d\n", 662 __func__, err); 663 err_count++; 664 } 665 } 666 667 err = usb_wwan_submit_delayed_urbs(port); 668 if (err) 669 err_count++; 670 671 for (j = 0; j < N_IN_URB; j++) { 672 urb = portdata->in_urbs[j]; 673 err = usb_submit_urb(urb, GFP_ATOMIC); 674 if (err < 0) { 675 dev_err(&port->dev, 676 "%s: submit read urb %d failed: %d\n", 677 __func__, i, err); 678 err_count++; 679 } 680 } 681 } 682 intfdata->suspended = 0; 683 spin_unlock_irq(&intfdata->susp_lock); 684 685 if (err_count) 686 return -EIO; 687 688 return 0; 689 } 690 EXPORT_SYMBOL(usb_wwan_resume); 691 #endif 692 693 MODULE_AUTHOR(DRIVER_AUTHOR); 694 MODULE_DESCRIPTION(DRIVER_DESC); 695 MODULE_LICENSE("GPL v2"); 696