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