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 i = 0; 152 left = count; 153 for (i = 0; left > 0 && i < N_OUT_URB; i++) { 154 todo = left; 155 if (todo > OUT_BUFLEN) 156 todo = OUT_BUFLEN; 157 158 this_urb = portdata->out_urbs[i]; 159 if (test_and_set_bit(i, &portdata->out_busy)) { 160 if (time_before(jiffies, 161 portdata->tx_start_time[i] + 10 * HZ)) 162 continue; 163 usb_unlink_urb(this_urb); 164 continue; 165 } 166 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__, 167 usb_pipeendpoint(this_urb->pipe), i); 168 169 err = usb_autopm_get_interface_async(port->serial->interface); 170 if (err < 0) { 171 clear_bit(i, &portdata->out_busy); 172 break; 173 } 174 175 /* send the data */ 176 memcpy(this_urb->transfer_buffer, buf, todo); 177 this_urb->transfer_buffer_length = todo; 178 179 spin_lock_irqsave(&intfdata->susp_lock, flags); 180 if (intfdata->suspended) { 181 usb_anchor_urb(this_urb, &portdata->delayed); 182 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 183 } else { 184 intfdata->in_flight++; 185 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 186 err = usb_submit_urb(this_urb, GFP_ATOMIC); 187 if (err) { 188 dev_err(&port->dev, 189 "%s: submit urb %d failed: %d\n", 190 __func__, i, err); 191 clear_bit(i, &portdata->out_busy); 192 spin_lock_irqsave(&intfdata->susp_lock, flags); 193 intfdata->in_flight--; 194 spin_unlock_irqrestore(&intfdata->susp_lock, 195 flags); 196 usb_autopm_put_interface_async(port->serial->interface); 197 break; 198 } 199 } 200 201 portdata->tx_start_time[i] = jiffies; 202 buf += todo; 203 left -= todo; 204 } 205 206 count -= left; 207 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count); 208 return count; 209 } 210 EXPORT_SYMBOL(usb_wwan_write); 211 212 static void usb_wwan_indat_callback(struct urb *urb) 213 { 214 int err; 215 int endpoint; 216 struct usb_serial_port *port; 217 struct device *dev; 218 unsigned char *data = urb->transfer_buffer; 219 int status = urb->status; 220 221 endpoint = usb_pipeendpoint(urb->pipe); 222 port = urb->context; 223 dev = &port->dev; 224 225 if (status) { 226 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n", 227 __func__, status, endpoint); 228 229 /* don't resubmit on fatal errors */ 230 if (status == -ESHUTDOWN || status == -ENOENT) 231 return; 232 } else { 233 if (urb->actual_length) { 234 tty_insert_flip_string(&port->port, data, 235 urb->actual_length); 236 tty_flip_buffer_push(&port->port); 237 } else 238 dev_dbg(dev, "%s: empty read urb received\n", __func__); 239 } 240 /* Resubmit urb so we continue receiving */ 241 err = usb_submit_urb(urb, GFP_ATOMIC); 242 if (err) { 243 if (err != -EPERM && err != -ENODEV) { 244 dev_err(dev, "%s: resubmit read urb failed. (%d)\n", 245 __func__, err); 246 /* busy also in error unless we are killed */ 247 usb_mark_last_busy(port->serial->dev); 248 } 249 } else { 250 usb_mark_last_busy(port->serial->dev); 251 } 252 } 253 254 static void usb_wwan_outdat_callback(struct urb *urb) 255 { 256 struct usb_serial_port *port; 257 struct usb_wwan_port_private *portdata; 258 struct usb_wwan_intf_private *intfdata; 259 unsigned long flags; 260 int i; 261 262 port = urb->context; 263 intfdata = usb_get_serial_data(port->serial); 264 265 usb_serial_port_softint(port); 266 usb_autopm_put_interface_async(port->serial->interface); 267 portdata = usb_get_serial_port_data(port); 268 spin_lock_irqsave(&intfdata->susp_lock, flags); 269 intfdata->in_flight--; 270 spin_unlock_irqrestore(&intfdata->susp_lock, flags); 271 272 for (i = 0; i < N_OUT_URB; ++i) { 273 if (portdata->out_urbs[i] == urb) { 274 smp_mb__before_atomic(); 275 clear_bit(i, &portdata->out_busy); 276 break; 277 } 278 } 279 } 280 281 unsigned int usb_wwan_write_room(struct tty_struct *tty) 282 { 283 struct usb_serial_port *port = tty->driver_data; 284 struct usb_wwan_port_private *portdata; 285 int i; 286 unsigned int data_len = 0; 287 struct urb *this_urb; 288 289 portdata = usb_get_serial_port_data(port); 290 291 for (i = 0; i < N_OUT_URB; i++) { 292 this_urb = portdata->out_urbs[i]; 293 if (this_urb && !test_bit(i, &portdata->out_busy)) 294 data_len += OUT_BUFLEN; 295 } 296 297 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len); 298 return data_len; 299 } 300 EXPORT_SYMBOL(usb_wwan_write_room); 301 302 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty) 303 { 304 struct usb_serial_port *port = tty->driver_data; 305 struct usb_wwan_port_private *portdata; 306 int i; 307 unsigned int data_len = 0; 308 struct urb *this_urb; 309 310 portdata = usb_get_serial_port_data(port); 311 312 for (i = 0; i < N_OUT_URB; i++) { 313 this_urb = portdata->out_urbs[i]; 314 /* FIXME: This locking is insufficient as this_urb may 315 go unused during the test */ 316 if (this_urb && test_bit(i, &portdata->out_busy)) 317 data_len += this_urb->transfer_buffer_length; 318 } 319 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len); 320 return data_len; 321 } 322 EXPORT_SYMBOL(usb_wwan_chars_in_buffer); 323 324 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port) 325 { 326 struct usb_wwan_port_private *portdata; 327 struct usb_wwan_intf_private *intfdata; 328 struct usb_serial *serial = port->serial; 329 int i, err; 330 struct urb *urb; 331 332 portdata = usb_get_serial_port_data(port); 333 intfdata = usb_get_serial_data(serial); 334 335 if (port->interrupt_in_urb) { 336 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 337 if (err) { 338 dev_err(&port->dev, "%s: submit int urb failed: %d\n", 339 __func__, err); 340 } 341 } 342 343 /* Start reading from the IN endpoint */ 344 for (i = 0; i < N_IN_URB; i++) { 345 urb = portdata->in_urbs[i]; 346 if (!urb) 347 continue; 348 err = usb_submit_urb(urb, GFP_KERNEL); 349 if (err) { 350 dev_err(&port->dev, 351 "%s: submit read urb %d failed: %d\n", 352 __func__, i, err); 353 } 354 } 355 356 spin_lock_irq(&intfdata->susp_lock); 357 if (++intfdata->open_ports == 1) 358 serial->interface->needs_remote_wakeup = 1; 359 spin_unlock_irq(&intfdata->susp_lock); 360 /* this balances a get in the generic USB serial code */ 361 usb_autopm_put_interface(serial->interface); 362 363 return 0; 364 } 365 EXPORT_SYMBOL(usb_wwan_open); 366 367 static void unbusy_queued_urb(struct urb *urb, 368 struct usb_wwan_port_private *portdata) 369 { 370 int i; 371 372 for (i = 0; i < N_OUT_URB; i++) { 373 if (urb == portdata->out_urbs[i]) { 374 clear_bit(i, &portdata->out_busy); 375 break; 376 } 377 } 378 } 379 380 void usb_wwan_close(struct usb_serial_port *port) 381 { 382 int i; 383 struct usb_serial *serial = port->serial; 384 struct usb_wwan_port_private *portdata; 385 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 386 struct urb *urb; 387 388 portdata = usb_get_serial_port_data(port); 389 390 /* 391 * Need to take susp_lock to make sure port is not already being 392 * resumed, but no need to hold it due to initialized 393 */ 394 spin_lock_irq(&intfdata->susp_lock); 395 if (--intfdata->open_ports == 0) 396 serial->interface->needs_remote_wakeup = 0; 397 spin_unlock_irq(&intfdata->susp_lock); 398 399 for (;;) { 400 urb = usb_get_from_anchor(&portdata->delayed); 401 if (!urb) 402 break; 403 unbusy_queued_urb(urb, portdata); 404 usb_autopm_put_interface_async(serial->interface); 405 } 406 407 for (i = 0; i < N_IN_URB; i++) 408 usb_kill_urb(portdata->in_urbs[i]); 409 for (i = 0; i < N_OUT_URB; i++) 410 usb_kill_urb(portdata->out_urbs[i]); 411 usb_kill_urb(port->interrupt_in_urb); 412 413 usb_autopm_get_interface_no_resume(serial->interface); 414 } 415 EXPORT_SYMBOL(usb_wwan_close); 416 417 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port, 418 int endpoint, 419 int dir, void *ctx, char *buf, int len, 420 void (*callback) (struct urb *)) 421 { 422 struct usb_serial *serial = port->serial; 423 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 424 struct urb *urb; 425 426 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */ 427 if (!urb) 428 return NULL; 429 430 usb_fill_bulk_urb(urb, serial->dev, 431 usb_sndbulkpipe(serial->dev, endpoint) | dir, 432 buf, len, callback, ctx); 433 434 if (intfdata->use_zlp && dir == USB_DIR_OUT) 435 urb->transfer_flags |= URB_ZERO_PACKET; 436 437 return urb; 438 } 439 440 int usb_wwan_port_probe(struct usb_serial_port *port) 441 { 442 struct usb_wwan_port_private *portdata; 443 struct urb *urb; 444 u8 *buffer; 445 int i; 446 447 if (!port->bulk_in_size || !port->bulk_out_size) 448 return -ENODEV; 449 450 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL); 451 if (!portdata) 452 return -ENOMEM; 453 454 init_usb_anchor(&portdata->delayed); 455 456 for (i = 0; i < N_IN_URB; i++) { 457 buffer = (u8 *)__get_free_page(GFP_KERNEL); 458 if (!buffer) 459 goto bail_out_error; 460 portdata->in_buffer[i] = buffer; 461 462 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress, 463 USB_DIR_IN, port, 464 buffer, IN_BUFLEN, 465 usb_wwan_indat_callback); 466 portdata->in_urbs[i] = urb; 467 } 468 469 for (i = 0; i < N_OUT_URB; i++) { 470 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL); 471 if (!buffer) 472 goto bail_out_error2; 473 portdata->out_buffer[i] = buffer; 474 475 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress, 476 USB_DIR_OUT, port, 477 buffer, OUT_BUFLEN, 478 usb_wwan_outdat_callback); 479 portdata->out_urbs[i] = urb; 480 } 481 482 usb_set_serial_port_data(port, portdata); 483 484 return 0; 485 486 bail_out_error2: 487 for (i = 0; i < N_OUT_URB; i++) { 488 usb_free_urb(portdata->out_urbs[i]); 489 kfree(portdata->out_buffer[i]); 490 } 491 bail_out_error: 492 for (i = 0; i < N_IN_URB; i++) { 493 usb_free_urb(portdata->in_urbs[i]); 494 free_page((unsigned long)portdata->in_buffer[i]); 495 } 496 kfree(portdata); 497 498 return -ENOMEM; 499 } 500 EXPORT_SYMBOL_GPL(usb_wwan_port_probe); 501 502 void usb_wwan_port_remove(struct usb_serial_port *port) 503 { 504 int i; 505 struct usb_wwan_port_private *portdata; 506 507 portdata = usb_get_serial_port_data(port); 508 usb_set_serial_port_data(port, NULL); 509 510 for (i = 0; i < N_IN_URB; i++) { 511 usb_free_urb(portdata->in_urbs[i]); 512 free_page((unsigned long)portdata->in_buffer[i]); 513 } 514 for (i = 0; i < N_OUT_URB; i++) { 515 usb_free_urb(portdata->out_urbs[i]); 516 kfree(portdata->out_buffer[i]); 517 } 518 519 kfree(portdata); 520 } 521 EXPORT_SYMBOL(usb_wwan_port_remove); 522 523 #ifdef CONFIG_PM 524 static void stop_urbs(struct usb_serial *serial) 525 { 526 int i, j; 527 struct usb_serial_port *port; 528 struct usb_wwan_port_private *portdata; 529 530 for (i = 0; i < serial->num_ports; ++i) { 531 port = serial->port[i]; 532 portdata = usb_get_serial_port_data(port); 533 if (!portdata) 534 continue; 535 for (j = 0; j < N_IN_URB; j++) 536 usb_kill_urb(portdata->in_urbs[j]); 537 for (j = 0; j < N_OUT_URB; j++) 538 usb_kill_urb(portdata->out_urbs[j]); 539 usb_kill_urb(port->interrupt_in_urb); 540 } 541 } 542 543 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) 544 { 545 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 546 547 spin_lock_irq(&intfdata->susp_lock); 548 if (PMSG_IS_AUTO(message)) { 549 if (intfdata->in_flight) { 550 spin_unlock_irq(&intfdata->susp_lock); 551 return -EBUSY; 552 } 553 } 554 intfdata->suspended = 1; 555 spin_unlock_irq(&intfdata->susp_lock); 556 557 stop_urbs(serial); 558 559 return 0; 560 } 561 EXPORT_SYMBOL(usb_wwan_suspend); 562 563 /* Caller must hold susp_lock. */ 564 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port) 565 { 566 struct usb_serial *serial = port->serial; 567 struct usb_wwan_intf_private *data = usb_get_serial_data(serial); 568 struct usb_wwan_port_private *portdata; 569 struct urb *urb; 570 int err_count = 0; 571 int err; 572 573 portdata = usb_get_serial_port_data(port); 574 575 for (;;) { 576 urb = usb_get_from_anchor(&portdata->delayed); 577 if (!urb) 578 break; 579 580 err = usb_submit_urb(urb, GFP_ATOMIC); 581 if (err) { 582 dev_err(&port->dev, "%s: submit urb failed: %d\n", 583 __func__, err); 584 err_count++; 585 unbusy_queued_urb(urb, portdata); 586 usb_autopm_put_interface_async(serial->interface); 587 continue; 588 } 589 data->in_flight++; 590 } 591 592 if (err_count) 593 return -EIO; 594 595 return 0; 596 } 597 598 int usb_wwan_resume(struct usb_serial *serial) 599 { 600 int i, j; 601 struct usb_serial_port *port; 602 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); 603 struct usb_wwan_port_private *portdata; 604 struct urb *urb; 605 int err; 606 int err_count = 0; 607 608 spin_lock_irq(&intfdata->susp_lock); 609 for (i = 0; i < serial->num_ports; i++) { 610 port = serial->port[i]; 611 612 if (!tty_port_initialized(&port->port)) 613 continue; 614 615 portdata = usb_get_serial_port_data(port); 616 617 if (port->interrupt_in_urb) { 618 err = usb_submit_urb(port->interrupt_in_urb, 619 GFP_ATOMIC); 620 if (err) { 621 dev_err(&port->dev, 622 "%s: submit int urb failed: %d\n", 623 __func__, err); 624 err_count++; 625 } 626 } 627 628 err = usb_wwan_submit_delayed_urbs(port); 629 if (err) 630 err_count++; 631 632 for (j = 0; j < N_IN_URB; j++) { 633 urb = portdata->in_urbs[j]; 634 err = usb_submit_urb(urb, GFP_ATOMIC); 635 if (err < 0) { 636 dev_err(&port->dev, 637 "%s: submit read urb %d failed: %d\n", 638 __func__, i, err); 639 err_count++; 640 } 641 } 642 } 643 intfdata->suspended = 0; 644 spin_unlock_irq(&intfdata->susp_lock); 645 646 if (err_count) 647 return -EIO; 648 649 return 0; 650 } 651 EXPORT_SYMBOL(usb_wwan_resume); 652 #endif 653 654 MODULE_AUTHOR(DRIVER_AUTHOR); 655 MODULE_DESCRIPTION(DRIVER_DESC); 656 MODULE_LICENSE("GPL v2"); 657