1 /* 2 * Opticon USB barcode to serial driver 3 * 4 * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com> 5 * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de> 6 * Copyright (C) 2008 - 2009 Novell Inc. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License version 10 * 2 as published by the Free Software Foundation. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/init.h> 15 #include <linux/tty.h> 16 #include <linux/tty_driver.h> 17 #include <linux/slab.h> 18 #include <linux/tty_flip.h> 19 #include <linux/serial.h> 20 #include <linux/module.h> 21 #include <linux/usb.h> 22 #include <linux/usb/serial.h> 23 #include <linux/uaccess.h> 24 25 #define CONTROL_RTS 0x02 26 #define RESEND_CTS_STATE 0x03 27 28 /* max number of write urbs in flight */ 29 #define URB_UPPER_LIMIT 8 30 31 /* This driver works for the Opticon 1D barcode reader 32 * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */ 33 #define DRIVER_DESC "Opticon USB barcode to serial driver (1D)" 34 35 static bool debug; 36 37 static const struct usb_device_id id_table[] = { 38 { USB_DEVICE(0x065a, 0x0009) }, 39 { }, 40 }; 41 MODULE_DEVICE_TABLE(usb, id_table); 42 43 /* This structure holds all of the individual device information */ 44 struct opticon_private { 45 struct usb_device *udev; 46 struct usb_serial *serial; 47 struct usb_serial_port *port; 48 unsigned char *bulk_in_buffer; 49 struct urb *bulk_read_urb; 50 int buffer_size; 51 u8 bulk_address; 52 spinlock_t lock; /* protects the following flags */ 53 bool throttled; 54 bool actually_throttled; 55 bool rts; 56 bool cts; 57 int outstanding_urbs; 58 }; 59 60 61 62 static void opticon_read_bulk_callback(struct urb *urb) 63 { 64 struct opticon_private *priv = urb->context; 65 unsigned char *data = urb->transfer_buffer; 66 struct usb_serial_port *port = priv->port; 67 int status = urb->status; 68 struct tty_struct *tty; 69 int result; 70 int data_length; 71 unsigned long flags; 72 73 switch (status) { 74 case 0: 75 /* success */ 76 break; 77 case -ECONNRESET: 78 case -ENOENT: 79 case -ESHUTDOWN: 80 /* this urb is terminated, clean up */ 81 dbg("%s - urb shutting down with status: %d", 82 __func__, status); 83 return; 84 default: 85 dbg("%s - nonzero urb status received: %d", 86 __func__, status); 87 goto exit; 88 } 89 90 usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, 91 data); 92 93 if (urb->actual_length > 2) { 94 data_length = urb->actual_length - 2; 95 96 /* 97 * Data from the device comes with a 2 byte header: 98 * 99 * <0x00><0x00>data... 100 * This is real data to be sent to the tty layer 101 * <0x00><0x01)level 102 * This is a CTS level change, the third byte is the CTS 103 * value (0 for low, 1 for high). 104 */ 105 if ((data[0] == 0x00) && (data[1] == 0x00)) { 106 /* real data, send it to the tty layer */ 107 tty = tty_port_tty_get(&port->port); 108 if (tty) { 109 tty_insert_flip_string(tty, data + 2, 110 data_length); 111 tty_flip_buffer_push(tty); 112 tty_kref_put(tty); 113 } 114 } else { 115 if ((data[0] == 0x00) && (data[1] == 0x01)) { 116 spin_lock_irqsave(&priv->lock, flags); 117 /* CTS status information package */ 118 if (data[2] == 0x00) 119 priv->cts = false; 120 else 121 priv->cts = true; 122 spin_unlock_irqrestore(&priv->lock, flags); 123 } else { 124 dev_dbg(&priv->udev->dev, 125 "Unknown data packet received from the device:" 126 " %2x %2x\n", 127 data[0], data[1]); 128 } 129 } 130 } else { 131 dev_dbg(&priv->udev->dev, 132 "Improper amount of data received from the device, " 133 "%d bytes", urb->actual_length); 134 } 135 136 exit: 137 spin_lock(&priv->lock); 138 139 /* Continue trying to always read if we should */ 140 if (!priv->throttled) { 141 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev, 142 usb_rcvbulkpipe(priv->udev, 143 priv->bulk_address), 144 priv->bulk_in_buffer, priv->buffer_size, 145 opticon_read_bulk_callback, priv); 146 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC); 147 if (result) 148 dev_err(&port->dev, 149 "%s - failed resubmitting read urb, error %d\n", 150 __func__, result); 151 } else 152 priv->actually_throttled = true; 153 spin_unlock(&priv->lock); 154 } 155 156 static int send_control_msg(struct usb_serial_port *port, u8 requesttype, 157 u8 val) 158 { 159 struct usb_serial *serial = port->serial; 160 int retval; 161 u8 buffer[2]; 162 163 buffer[0] = val; 164 /* Send the message to the vendor control endpoint 165 * of the connected device */ 166 retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 167 requesttype, 168 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE, 169 0, 0, buffer, 1, 0); 170 171 return retval; 172 } 173 174 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port) 175 { 176 struct opticon_private *priv = usb_get_serial_data(port->serial); 177 unsigned long flags; 178 int result = 0; 179 180 spin_lock_irqsave(&priv->lock, flags); 181 priv->throttled = false; 182 priv->actually_throttled = false; 183 priv->port = port; 184 priv->rts = false; 185 spin_unlock_irqrestore(&priv->lock, flags); 186 187 /* Clear RTS line */ 188 send_control_msg(port, CONTROL_RTS, 0); 189 190 /* Setup the read URB and start reading from the device */ 191 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev, 192 usb_rcvbulkpipe(priv->udev, 193 priv->bulk_address), 194 priv->bulk_in_buffer, priv->buffer_size, 195 opticon_read_bulk_callback, priv); 196 197 /* clear the halt status of the enpoint */ 198 usb_clear_halt(priv->udev, priv->bulk_read_urb->pipe); 199 200 result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL); 201 if (result) 202 dev_err(&port->dev, 203 "%s - failed resubmitting read urb, error %d\n", 204 __func__, result); 205 /* Request CTS line state, sometimes during opening the current 206 * CTS state can be missed. */ 207 send_control_msg(port, RESEND_CTS_STATE, 1); 208 return result; 209 } 210 211 static void opticon_close(struct usb_serial_port *port) 212 { 213 struct opticon_private *priv = usb_get_serial_data(port->serial); 214 215 /* shutdown our urbs */ 216 usb_kill_urb(priv->bulk_read_urb); 217 } 218 219 static void opticon_write_control_callback(struct urb *urb) 220 { 221 struct opticon_private *priv = urb->context; 222 int status = urb->status; 223 unsigned long flags; 224 225 /* free up the transfer buffer, as usb_free_urb() does not do this */ 226 kfree(urb->transfer_buffer); 227 228 /* setup packet may be set if we're using it for writing */ 229 kfree(urb->setup_packet); 230 231 if (status) 232 dbg("%s - nonzero write bulk status received: %d", 233 __func__, status); 234 235 spin_lock_irqsave(&priv->lock, flags); 236 --priv->outstanding_urbs; 237 spin_unlock_irqrestore(&priv->lock, flags); 238 239 usb_serial_port_softint(priv->port); 240 } 241 242 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, 243 const unsigned char *buf, int count) 244 { 245 struct opticon_private *priv = usb_get_serial_data(port->serial); 246 struct usb_serial *serial = port->serial; 247 struct urb *urb; 248 unsigned char *buffer; 249 unsigned long flags; 250 int status; 251 struct usb_ctrlrequest *dr; 252 253 spin_lock_irqsave(&priv->lock, flags); 254 if (priv->outstanding_urbs > URB_UPPER_LIMIT) { 255 spin_unlock_irqrestore(&priv->lock, flags); 256 dbg("%s - write limit hit", __func__); 257 return 0; 258 } 259 priv->outstanding_urbs++; 260 spin_unlock_irqrestore(&priv->lock, flags); 261 262 buffer = kmalloc(count, GFP_ATOMIC); 263 if (!buffer) { 264 dev_err(&port->dev, "out of memory\n"); 265 count = -ENOMEM; 266 267 goto error_no_buffer; 268 } 269 270 urb = usb_alloc_urb(0, GFP_ATOMIC); 271 if (!urb) { 272 dev_err(&port->dev, "no more free urbs\n"); 273 count = -ENOMEM; 274 goto error_no_urb; 275 } 276 277 memcpy(buffer, buf, count); 278 279 usb_serial_debug_data(debug, &port->dev, __func__, count, buffer); 280 281 /* The conncected devices do not have a bulk write endpoint, 282 * to transmit data to de barcode device the control endpoint is used */ 283 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO); 284 if (!dr) { 285 dev_err(&port->dev, "out of memory\n"); 286 count = -ENOMEM; 287 goto error; 288 } 289 290 dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; 291 dr->bRequest = 0x01; 292 dr->wValue = 0; 293 dr->wIndex = 0; 294 dr->wLength = cpu_to_le16(count); 295 296 usb_fill_control_urb(urb, serial->dev, 297 usb_sndctrlpipe(serial->dev, 0), 298 (unsigned char *)dr, buffer, count, 299 opticon_write_control_callback, priv); 300 301 /* send it down the pipe */ 302 status = usb_submit_urb(urb, GFP_ATOMIC); 303 if (status) { 304 dev_err(&port->dev, 305 "%s - usb_submit_urb(write endpoint) failed status = %d\n", 306 __func__, status); 307 count = status; 308 goto error; 309 } 310 311 /* we are done with this urb, so let the host driver 312 * really free it when it is finished with it */ 313 usb_free_urb(urb); 314 315 return count; 316 error: 317 usb_free_urb(urb); 318 error_no_urb: 319 kfree(buffer); 320 error_no_buffer: 321 spin_lock_irqsave(&priv->lock, flags); 322 --priv->outstanding_urbs; 323 spin_unlock_irqrestore(&priv->lock, flags); 324 return count; 325 } 326 327 static int opticon_write_room(struct tty_struct *tty) 328 { 329 struct usb_serial_port *port = tty->driver_data; 330 struct opticon_private *priv = usb_get_serial_data(port->serial); 331 unsigned long flags; 332 333 /* 334 * We really can take almost anything the user throws at us 335 * but let's pick a nice big number to tell the tty 336 * layer that we have lots of free space, unless we don't. 337 */ 338 spin_lock_irqsave(&priv->lock, flags); 339 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { 340 spin_unlock_irqrestore(&priv->lock, flags); 341 dbg("%s - write limit hit", __func__); 342 return 0; 343 } 344 spin_unlock_irqrestore(&priv->lock, flags); 345 346 return 2048; 347 } 348 349 static void opticon_throttle(struct tty_struct *tty) 350 { 351 struct usb_serial_port *port = tty->driver_data; 352 struct opticon_private *priv = usb_get_serial_data(port->serial); 353 unsigned long flags; 354 355 spin_lock_irqsave(&priv->lock, flags); 356 priv->throttled = true; 357 spin_unlock_irqrestore(&priv->lock, flags); 358 } 359 360 361 static void opticon_unthrottle(struct tty_struct *tty) 362 { 363 struct usb_serial_port *port = tty->driver_data; 364 struct opticon_private *priv = usb_get_serial_data(port->serial); 365 unsigned long flags; 366 int result, was_throttled; 367 368 spin_lock_irqsave(&priv->lock, flags); 369 priv->throttled = false; 370 was_throttled = priv->actually_throttled; 371 priv->actually_throttled = false; 372 spin_unlock_irqrestore(&priv->lock, flags); 373 374 if (was_throttled) { 375 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC); 376 if (result) 377 dev_err(&port->dev, 378 "%s - failed submitting read urb, error %d\n", 379 __func__, result); 380 } 381 } 382 383 static int opticon_tiocmget(struct tty_struct *tty) 384 { 385 struct usb_serial_port *port = tty->driver_data; 386 struct opticon_private *priv = usb_get_serial_data(port->serial); 387 unsigned long flags; 388 int result = 0; 389 390 spin_lock_irqsave(&priv->lock, flags); 391 if (priv->rts) 392 result |= TIOCM_RTS; 393 if (priv->cts) 394 result |= TIOCM_CTS; 395 spin_unlock_irqrestore(&priv->lock, flags); 396 397 dbg("%s - %x", __func__, result); 398 return result; 399 } 400 401 static int opticon_tiocmset(struct tty_struct *tty, 402 unsigned int set, unsigned int clear) 403 { 404 struct usb_serial_port *port = tty->driver_data; 405 struct usb_serial *serial = port->serial; 406 struct opticon_private *priv = usb_get_serial_data(port->serial); 407 unsigned long flags; 408 bool rts; 409 bool changed = false; 410 int ret; 411 412 /* We only support RTS so we only handle that */ 413 spin_lock_irqsave(&priv->lock, flags); 414 415 rts = priv->rts; 416 if (set & TIOCM_RTS) 417 priv->rts = true; 418 if (clear & TIOCM_RTS) 419 priv->rts = false; 420 changed = rts ^ priv->rts; 421 spin_unlock_irqrestore(&priv->lock, flags); 422 423 if (!changed) 424 return 0; 425 426 /* Send the new RTS state to the connected device */ 427 mutex_lock(&serial->disc_mutex); 428 if (!serial->disconnected) 429 ret = send_control_msg(port, CONTROL_RTS, !rts); 430 else 431 ret = -ENODEV; 432 mutex_unlock(&serial->disc_mutex); 433 434 return ret; 435 } 436 437 static int get_serial_info(struct opticon_private *priv, 438 struct serial_struct __user *serial) 439 { 440 struct serial_struct tmp; 441 442 if (!serial) 443 return -EFAULT; 444 445 memset(&tmp, 0x00, sizeof(tmp)); 446 447 /* fake emulate a 16550 uart to make userspace code happy */ 448 tmp.type = PORT_16550A; 449 tmp.line = priv->serial->minor; 450 tmp.port = 0; 451 tmp.irq = 0; 452 tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ; 453 tmp.xmit_fifo_size = 1024; 454 tmp.baud_base = 9600; 455 tmp.close_delay = 5*HZ; 456 tmp.closing_wait = 30*HZ; 457 458 if (copy_to_user(serial, &tmp, sizeof(*serial))) 459 return -EFAULT; 460 return 0; 461 } 462 463 static int opticon_ioctl(struct tty_struct *tty, 464 unsigned int cmd, unsigned long arg) 465 { 466 struct usb_serial_port *port = tty->driver_data; 467 struct opticon_private *priv = usb_get_serial_data(port->serial); 468 469 dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd); 470 471 switch (cmd) { 472 case TIOCGSERIAL: 473 return get_serial_info(priv, 474 (struct serial_struct __user *)arg); 475 } 476 477 return -ENOIOCTLCMD; 478 } 479 480 static int opticon_startup(struct usb_serial *serial) 481 { 482 struct opticon_private *priv; 483 struct usb_host_interface *intf; 484 int i; 485 int retval = -ENOMEM; 486 bool bulk_in_found = false; 487 488 /* create our private serial structure */ 489 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 490 if (priv == NULL) { 491 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__); 492 return -ENOMEM; 493 } 494 spin_lock_init(&priv->lock); 495 priv->serial = serial; 496 priv->port = serial->port[0]; 497 priv->udev = serial->dev; 498 priv->outstanding_urbs = 0; /* Init the outstanding urbs */ 499 500 /* find our bulk endpoint */ 501 intf = serial->interface->altsetting; 502 for (i = 0; i < intf->desc.bNumEndpoints; ++i) { 503 struct usb_endpoint_descriptor *endpoint; 504 505 endpoint = &intf->endpoint[i].desc; 506 if (!usb_endpoint_is_bulk_in(endpoint)) 507 continue; 508 509 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL); 510 if (!priv->bulk_read_urb) { 511 dev_err(&priv->udev->dev, "out of memory\n"); 512 goto error; 513 } 514 515 priv->buffer_size = usb_endpoint_maxp(endpoint) * 2; 516 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL); 517 if (!priv->bulk_in_buffer) { 518 dev_err(&priv->udev->dev, "out of memory\n"); 519 goto error; 520 } 521 522 priv->bulk_address = endpoint->bEndpointAddress; 523 524 bulk_in_found = true; 525 break; 526 } 527 528 if (!bulk_in_found) { 529 dev_err(&priv->udev->dev, 530 "Error - the proper endpoints were not found!\n"); 531 goto error; 532 } 533 534 usb_set_serial_data(serial, priv); 535 return 0; 536 537 error: 538 usb_free_urb(priv->bulk_read_urb); 539 kfree(priv->bulk_in_buffer); 540 kfree(priv); 541 return retval; 542 } 543 544 static void opticon_disconnect(struct usb_serial *serial) 545 { 546 struct opticon_private *priv = usb_get_serial_data(serial); 547 548 usb_kill_urb(priv->bulk_read_urb); 549 usb_free_urb(priv->bulk_read_urb); 550 } 551 552 static void opticon_release(struct usb_serial *serial) 553 { 554 struct opticon_private *priv = usb_get_serial_data(serial); 555 556 kfree(priv->bulk_in_buffer); 557 kfree(priv); 558 } 559 560 static int opticon_suspend(struct usb_interface *intf, pm_message_t message) 561 { 562 struct usb_serial *serial = usb_get_intfdata(intf); 563 struct opticon_private *priv = usb_get_serial_data(serial); 564 565 usb_kill_urb(priv->bulk_read_urb); 566 return 0; 567 } 568 569 static int opticon_resume(struct usb_interface *intf) 570 { 571 struct usb_serial *serial = usb_get_intfdata(intf); 572 struct opticon_private *priv = usb_get_serial_data(serial); 573 struct usb_serial_port *port = serial->port[0]; 574 int result; 575 576 mutex_lock(&port->port.mutex); 577 /* This is protected by the port mutex against close/open */ 578 if (test_bit(ASYNCB_INITIALIZED, &port->port.flags)) 579 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO); 580 else 581 result = 0; 582 mutex_unlock(&port->port.mutex); 583 return result; 584 } 585 586 static struct usb_driver opticon_driver = { 587 .name = "opticon", 588 .suspend = opticon_suspend, 589 .resume = opticon_resume, 590 .id_table = id_table, 591 }; 592 593 static struct usb_serial_driver opticon_device = { 594 .driver = { 595 .owner = THIS_MODULE, 596 .name = "opticon", 597 }, 598 .id_table = id_table, 599 .num_ports = 1, 600 .attach = opticon_startup, 601 .open = opticon_open, 602 .close = opticon_close, 603 .write = opticon_write, 604 .write_room = opticon_write_room, 605 .disconnect = opticon_disconnect, 606 .release = opticon_release, 607 .throttle = opticon_throttle, 608 .unthrottle = opticon_unthrottle, 609 .ioctl = opticon_ioctl, 610 .tiocmget = opticon_tiocmget, 611 .tiocmset = opticon_tiocmset, 612 }; 613 614 static struct usb_serial_driver * const serial_drivers[] = { 615 &opticon_device, NULL 616 }; 617 618 module_usb_serial_driver(serial_drivers, id_table); 619 620 MODULE_DESCRIPTION(DRIVER_DESC); 621 MODULE_LICENSE("GPL"); 622 623 module_param(debug, bool, S_IRUGO | S_IWUSR); 624 MODULE_PARM_DESC(debug, "Debug enabled or not"); 625