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