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_write(struct tty_struct *tty, struct usb_serial_port *port, 136 const unsigned char *buf, int count) 137 { 138 struct usb_wwan_port_private *portdata; 139 struct usb_wwan_intf_private *intfdata; 140 int i; 141 int left, todo; 142 struct urb *this_urb = NULL; /* spurious */ 143 int err; 144 unsigned long flags; 145 146 portdata = usb_get_serial_port_data(port); 147 intfdata = usb_get_serial_data(port->serial); 148 149 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count); 150 151 left = count; 152 for (i = 0; left > 0 && i < N_OUT_URB; i++) { 153 todo = left; 154 if (todo > OUT_BUFLEN) 155 todo = OUT_BUFLEN; 156 157 this_urb = portdata->out_urbs[i]; 158 if (test_and_set_bit(i, &portdata->out_busy)) { 159 if (time_before(jiffies, 160 portdata->tx_start_time[i] + 10 * HZ)) 161 continue; 162 usb_unlink_urb(this_urb); 163 continue; 164 } 165 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__, 166 usb_pipeendpoint(this_urb->pipe), i); 167 168 err = usb_autopm_get_interface_async(port->serial->interface); 169 if (err < 0) { 170 clear_bit(i, &portdata->out_busy); 171 break; 172 } 173 174 /* send the data */ 175 memcpy(this_urb->transfer_buffer, buf, todo); 176 this_urb->transfer_buffer_length = todo; 177 178 spin_lock_irqsave(&intfdata->susp_lock, flags); 179 if (intfdata->suspended) { 180 usb_anchor_urb(this_urb, &portdata->delayed); 181 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 182 } else { 183 intfdata->in_flight++; 184 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 185 err = usb_submit_urb(this_urb, GFP_ATOMIC); 186 if (err) { 187 dev_err(&port->dev, 188 "%s: submit urb %d failed: %d\n", 189 __func__, i, err); 190 clear_bit(i, &portdata->out_busy); 191 spin_lock_irqsave(&intfdata->susp_lock, flags); 192 intfdata->in_flight--; 193 spin_unlock_irqrestore(&intfdata->susp_lock, 194 flags); 195 usb_autopm_put_interface_async(port->serial->interface); 196 break; 197 } 198 } 199 200 portdata->tx_start_time[i] = jiffies; 201 buf += todo; 202 left -= todo; 203 } 204 205 count -= left; 206 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count); 207 return count; 208 } 209 EXPORT_SYMBOL(usb_wwan_write); 210 211 static void usb_wwan_indat_callback(struct urb *urb) 212 { 213 int err; 214 int endpoint; 215 struct usb_serial_port *port; 216 struct device *dev; 217 unsigned char *data = urb->transfer_buffer; 218 int status = urb->status; 219 220 endpoint = usb_pipeendpoint(urb->pipe); 221 port = urb->context; 222 dev = &port->dev; 223 224 if (status) { 225 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n", 226 __func__, status, endpoint); 227 228 /* don't resubmit on fatal errors */ 229 if (status == -ESHUTDOWN || status == -ENOENT) 230 return; 231 } else { 232 if (urb->actual_length) { 233 tty_insert_flip_string(&port->port, data, 234 urb->actual_length); 235 tty_flip_buffer_push(&port->port); 236 } else 237 dev_dbg(dev, "%s: empty read urb received\n", __func__); 238 } 239 /* Resubmit urb so we continue receiving */ 240 err = usb_submit_urb(urb, GFP_ATOMIC); 241 if (err) { 242 if (err != -EPERM && err != -ENODEV) { 243 dev_err(dev, "%s: resubmit read urb failed. (%d)\n", 244 __func__, err); 245 /* busy also in error unless we are killed */ 246 usb_mark_last_busy(port->serial->dev); 247 } 248 } else { 249 usb_mark_last_busy(port->serial->dev); 250 } 251 } 252 253 static void usb_wwan_outdat_callback(struct urb *urb) 254 { 255 struct usb_serial_port *port; 256 struct usb_wwan_port_private *portdata; 257 struct usb_wwan_intf_private *intfdata; 258 unsigned long flags; 259 int i; 260 261 port = urb->context; 262 intfdata = usb_get_serial_data(port->serial); 263 264 usb_serial_port_softint(port); 265 usb_autopm_put_interface_async(port->serial->interface); 266 portdata = usb_get_serial_port_data(port); 267 spin_lock_irqsave(&intfdata->susp_lock, flags); 268 intfdata->in_flight--; 269 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 270 271 for (i = 0; i < N_OUT_URB; ++i) { 272 if (portdata->out_urbs[i] == urb) { 273 smp_mb__before_atomic(); 274 clear_bit(i, &portdata->out_busy); 275 break; 276 } 277 } 278 } 279 280 unsigned int usb_wwan_write_room(struct tty_struct *tty) 281 { 282 struct usb_serial_port *port = tty->driver_data; 283 struct usb_wwan_port_private *portdata; 284 int i; 285 unsigned int data_len = 0; 286 struct urb *this_urb; 287 288 portdata = usb_get_serial_port_data(port); 289 290 for (i = 0; i < N_OUT_URB; i++) { 291 this_urb = portdata->out_urbs[i]; 292 if (this_urb && !test_bit(i, &portdata->out_busy)) 293 data_len += OUT_BUFLEN; 294 } 295 296 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len); 297 return data_len; 298 } 299 EXPORT_SYMBOL(usb_wwan_write_room); 300 301 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty) 302 { 303 struct usb_serial_port *port = tty->driver_data; 304 struct usb_wwan_port_private *portdata; 305 int i; 306 unsigned int data_len = 0; 307 struct urb *this_urb; 308 309 portdata = usb_get_serial_port_data(port); 310 311 for (i = 0; i < N_OUT_URB; i++) { 312 this_urb = portdata->out_urbs[i]; 313 /* FIXME: This locking is insufficient as this_urb may 314 go unused during the test */ 315 if (this_urb && test_bit(i, &portdata->out_busy)) 316 data_len += this_urb->transfer_buffer_length; 317 } 318 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len); 319 return data_len; 320 } 321 EXPORT_SYMBOL(usb_wwan_chars_in_buffer); 322 323 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port) 324 { 325 struct usb_wwan_port_private *portdata; 326 struct usb_wwan_intf_private *intfdata; 327 struct usb_serial *serial = port->serial; 328 int i, err; 329 struct urb *urb; 330 331 portdata = usb_get_serial_port_data(port); 332 intfdata = usb_get_serial_data(serial); 333 334 if (port->interrupt_in_urb) { 335 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 336 if (err) { 337 dev_err(&port->dev, "%s: submit int urb failed: %d\n", 338 __func__, err); 339 } 340 } 341 342 /* Start reading from the IN endpoint */ 343 for (i = 0; i < N_IN_URB; i++) { 344 urb = portdata->in_urbs[i]; 345 if (!urb) 346 continue; 347 err = usb_submit_urb(urb, GFP_KERNEL); 348 if (err) { 349 dev_err(&port->dev, 350 "%s: submit read urb %d failed: %d\n", 351 __func__, i, err); 352 } 353 } 354 355 spin_lock_irq(&intfdata->susp_lock); 356 if (++intfdata->open_ports == 1) 357 serial->interface->needs_remote_wakeup = 1; 358 spin_unlock_irq(&intfdata->susp_lock); 359 /* this balances a get in the generic USB serial code */ 360 usb_autopm_put_interface(serial->interface); 361 362 return 0; 363 } 364 EXPORT_SYMBOL(usb_wwan_open); 365 366 static void unbusy_queued_urb(struct urb *urb, 367 struct usb_wwan_port_private *portdata) 368 { 369 int i; 370 371 for (i = 0; i < N_OUT_URB; i++) { 372 if (urb == portdata->out_urbs[i]) { 373 clear_bit(i, &portdata->out_busy); 374 break; 375 } 376 } 377 } 378 379 void usb_wwan_close(struct usb_serial_port *port) 380 { 381 int i; 382 struct usb_serial *serial = port->serial; 383 struct usb_wwan_port_private *portdata; 384 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 385 struct urb *urb; 386 387 portdata = usb_get_serial_port_data(port); 388 389 /* 390 * Need to take susp_lock to make sure port is not already being 391 * resumed, but no need to hold it due to initialized 392 */ 393 spin_lock_irq(&intfdata->susp_lock); 394 if (--intfdata->open_ports == 0) 395 serial->interface->needs_remote_wakeup = 0; 396 spin_unlock_irq(&intfdata->susp_lock); 397 398 for (;;) { 399 urb = usb_get_from_anchor(&portdata->delayed); 400 if (!urb) 401 break; 402 unbusy_queued_urb(urb, portdata); 403 usb_autopm_put_interface_async(serial->interface); 404 } 405 406 for (i = 0; i < N_IN_URB; i++) 407 usb_kill_urb(portdata->in_urbs[i]); 408 for (i = 0; i < N_OUT_URB; i++) 409 usb_kill_urb(portdata->out_urbs[i]); 410 usb_kill_urb(port->interrupt_in_urb); 411 412 usb_autopm_get_interface_no_resume(serial->interface); 413 } 414 EXPORT_SYMBOL(usb_wwan_close); 415 416 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port, 417 int endpoint, 418 int dir, void *ctx, char *buf, int len, 419 void (*callback) (struct urb *)) 420 { 421 struct usb_serial *serial = port->serial; 422 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 423 struct urb *urb; 424 425 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */ 426 if (!urb) 427 return NULL; 428 429 usb_fill_bulk_urb(urb, serial->dev, 430 usb_sndbulkpipe(serial->dev, endpoint) | dir, 431 buf, len, callback, ctx); 432 433 if (intfdata->use_zlp && dir == USB_DIR_OUT) 434 urb->transfer_flags |= URB_ZERO_PACKET; 435 436 return urb; 437 } 438 439 int usb_wwan_port_probe(struct usb_serial_port *port) 440 { 441 struct usb_wwan_port_private *portdata; 442 struct urb *urb; 443 u8 *buffer; 444 int i; 445 446 if (!port->bulk_in_size || !port->bulk_out_size) 447 return -ENODEV; 448 449 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL); 450 if (!portdata) 451 return -ENOMEM; 452 453 init_usb_anchor(&portdata->delayed); 454 455 for (i = 0; i < N_IN_URB; i++) { 456 buffer = (u8 *)__get_free_page(GFP_KERNEL); 457 if (!buffer) 458 goto bail_out_error; 459 portdata->in_buffer[i] = buffer; 460 461 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress, 462 USB_DIR_IN, port, 463 buffer, IN_BUFLEN, 464 usb_wwan_indat_callback); 465 portdata->in_urbs[i] = urb; 466 } 467 468 for (i = 0; i < N_OUT_URB; i++) { 469 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL); 470 if (!buffer) 471 goto bail_out_error2; 472 portdata->out_buffer[i] = buffer; 473 474 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress, 475 USB_DIR_OUT, port, 476 buffer, OUT_BUFLEN, 477 usb_wwan_outdat_callback); 478 portdata->out_urbs[i] = urb; 479 } 480 481 usb_set_serial_port_data(port, portdata); 482 483 return 0; 484 485 bail_out_error2: 486 for (i = 0; i < N_OUT_URB; i++) { 487 usb_free_urb(portdata->out_urbs[i]); 488 kfree(portdata->out_buffer[i]); 489 } 490 bail_out_error: 491 for (i = 0; i < N_IN_URB; i++) { 492 usb_free_urb(portdata->in_urbs[i]); 493 free_page((unsigned long)portdata->in_buffer[i]); 494 } 495 kfree(portdata); 496 497 return -ENOMEM; 498 } 499 EXPORT_SYMBOL_GPL(usb_wwan_port_probe); 500 501 void usb_wwan_port_remove(struct usb_serial_port *port) 502 { 503 int i; 504 struct usb_wwan_port_private *portdata; 505 506 portdata = usb_get_serial_port_data(port); 507 usb_set_serial_port_data(port, NULL); 508 509 for (i = 0; i < N_IN_URB; i++) { 510 usb_free_urb(portdata->in_urbs[i]); 511 free_page((unsigned long)portdata->in_buffer[i]); 512 } 513 for (i = 0; i < N_OUT_URB; i++) { 514 usb_free_urb(portdata->out_urbs[i]); 515 kfree(portdata->out_buffer[i]); 516 } 517 518 kfree(portdata); 519 } 520 EXPORT_SYMBOL(usb_wwan_port_remove); 521 522 #ifdef CONFIG_PM 523 static void stop_urbs(struct usb_serial *serial) 524 { 525 int i, j; 526 struct usb_serial_port *port; 527 struct usb_wwan_port_private *portdata; 528 529 for (i = 0; i < serial->num_ports; ++i) { 530 port = serial->port[i]; 531 portdata = usb_get_serial_port_data(port); 532 if (!portdata) 533 continue; 534 for (j = 0; j < N_IN_URB; j++) 535 usb_kill_urb(portdata->in_urbs[j]); 536 for (j = 0; j < N_OUT_URB; j++) 537 usb_kill_urb(portdata->out_urbs[j]); 538 usb_kill_urb(port->interrupt_in_urb); 539 } 540 } 541 542 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) 543 { 544 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 545 546 spin_lock_irq(&intfdata->susp_lock); 547 if (PMSG_IS_AUTO(message)) { 548 if (intfdata->in_flight) { 549 spin_unlock_irq(&intfdata->susp_lock); 550 return -EBUSY; 551 } 552 } 553 intfdata->suspended = 1; 554 spin_unlock_irq(&intfdata->susp_lock); 555 556 stop_urbs(serial); 557 558 return 0; 559 } 560 EXPORT_SYMBOL(usb_wwan_suspend); 561 562 /* Caller must hold susp_lock. */ 563 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port) 564 { 565 struct usb_serial *serial = port->serial; 566 struct usb_wwan_intf_private *data = usb_get_serial_data(serial); 567 struct usb_wwan_port_private *portdata; 568 struct urb *urb; 569 int err_count = 0; 570 int err; 571 572 portdata = usb_get_serial_port_data(port); 573 574 for (;;) { 575 urb = usb_get_from_anchor(&portdata->delayed); 576 if (!urb) 577 break; 578 579 err = usb_submit_urb(urb, GFP_ATOMIC); 580 if (err) { 581 dev_err(&port->dev, "%s: submit urb failed: %d\n", 582 __func__, err); 583 err_count++; 584 unbusy_queued_urb(urb, portdata); 585 usb_autopm_put_interface_async(serial->interface); 586 continue; 587 } 588 data->in_flight++; 589 } 590 591 if (err_count) 592 return -EIO; 593 594 return 0; 595 } 596 597 int usb_wwan_resume(struct usb_serial *serial) 598 { 599 int i, j; 600 struct usb_serial_port *port; 601 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 602 struct usb_wwan_port_private *portdata; 603 struct urb *urb; 604 int err; 605 int err_count = 0; 606 607 spin_lock_irq(&intfdata->susp_lock); 608 for (i = 0; i < serial->num_ports; i++) { 609 port = serial->port[i]; 610 611 if (!tty_port_initialized(&port->port)) 612 continue; 613 614 portdata = usb_get_serial_port_data(port); 615 616 if (port->interrupt_in_urb) { 617 err = usb_submit_urb(port->interrupt_in_urb, 618 GFP_ATOMIC); 619 if (err) { 620 dev_err(&port->dev, 621 "%s: submit int urb failed: %d\n", 622 __func__, err); 623 err_count++; 624 } 625 } 626 627 err = usb_wwan_submit_delayed_urbs(port); 628 if (err) 629 err_count++; 630 631 for (j = 0; j < N_IN_URB; j++) { 632 urb = portdata->in_urbs[j]; 633 err = usb_submit_urb(urb, GFP_ATOMIC); 634 if (err < 0) { 635 dev_err(&port->dev, 636 "%s: submit read urb %d failed: %d\n", 637 __func__, i, err); 638 err_count++; 639 } 640 } 641 } 642 intfdata->suspended = 0; 643 spin_unlock_irq(&intfdata->susp_lock); 644 645 if (err_count) 646 return -EIO; 647 648 return 0; 649 } 650 EXPORT_SYMBOL(usb_wwan_resume); 651 #endif 652 653 MODULE_AUTHOR(DRIVER_AUTHOR); 654 MODULE_DESCRIPTION(DRIVER_DESC); 655 MODULE_LICENSE("GPL v2"); 656