SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/usb/serial/opticon.c

   1 /*
   2  * Opticon USB barcode to serial driver
   3  *
   4  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
   5  * Copyright (C) 2008 - 2009 Novell Inc.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License version
   9  *      2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/tty.h>
  15 #include <linux/tty_driver.h>
  16 #include <linux/tty_flip.h>
  17 #include <linux/serial.h>
  18 #include <linux/module.h>
  19 #include <linux/usb.h>
  20 #include <linux/usb/serial.h>
  21 #include <linux/uaccess.h>
  22
  23 static int debug;
  24
  25 static const struct usb_device_id id_table[] = {
  26         { USB_DEVICE(0x065a, 0x0009) },
  27         { },
  28 };
  29 MODULE_DEVICE_TABLE(usb, id_table);
  30
  31 /* This structure holds all of the individual device information */
  32 struct opticon_private {
  33         struct usb_device *udev;
  34         struct usb_serial *serial;
  35         struct usb_serial_port *port;
  36         unsigned char *bulk_in_buffer;
  37         struct urb *bulk_read_urb;
  38         int buffer_size;
  39         u8 bulk_address;
  40         spinlock_t lock;        /* protects the following flags */
  41         bool throttled;
  42         bool actually_throttled;
  43         bool rts;
  44         int outstanding_urbs;
  45 };
  46
  47 /* max number of write urbs in flight */
  48 #define URB_UPPER_LIMIT 4
  49
  50 static void opticon_bulk_callback(struct urb *urb)
  51 {
  52         struct opticon_private *priv = urb->context;
  53         unsigned char *data = urb->transfer_buffer;
  54         struct usb_serial_port *port = priv->port;
  55         int status = urb->status;
  56         struct tty_struct *tty;
  57         int result;
  58         int data_length;
  59
  60         dbg("%s - port %d", __func__, port->number);
  61
  62         switch (status) {
  63         case 0:
  64                 /* success */
  65                 break;
  66         case -ECONNRESET:
  67         case -ENOENT:
  68         case -ESHUTDOWN:
  69                 /* this urb is terminated, clean up */
  70                 dbg("%s - urb shutting down with status: %d",
  71                     __func__, status);
  72                 return;
  73         default:
  74                 dbg("%s - nonzero urb status received: %d",
  75                     __func__, status);
  76                 goto exit;
  77         }
  78
  79         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
  80                               data);
  81
  82         if (urb->actual_length > 2) {
  83                 data_length = urb->actual_length - 2;
  84
  85                 /*
  86                  * Data from the device comes with a 2 byte header:
  87                  *
  88                  * <0x00><0x00>data...
  89                  *      This is real data to be sent to the tty layer
  90                  * <0x00><0x01)level
  91                  *      This is a RTS level change, the third byte is the RTS
  92                  *      value (0 for low, 1 for high).
  93                  */
  94                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
  95                         /* real data, send it to the tty layer */
  96                         tty = tty_port_tty_get(&port->port);
  97                         if (tty) {
  98                                 tty_insert_flip_string(tty, data,
  99                                                                data_length);
 100                                 tty_flip_buffer_push(tty);
 101                                 tty_kref_put(tty);
 102                         }
 103                 } else {
 104                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 105                                 if (data[2] == 0x00)
 106                                         priv->rts = false;
 107                                 else
 108                                         priv->rts = true;
 109                         } else {
 110                         dev_dbg(&priv->udev->dev,
 111                                 "Unknown data packet received from the device:"
 112                                 " %2x %2x\n",
 113                                 data[0], data[1]);
 114                         }
 115                 }
 116         } else {
 117                 dev_dbg(&priv->udev->dev,
 118                         "Improper amount of data received from the device, "
 119                         "%d bytes", urb->actual_length);
 120         }
 121
 122 exit:
 123         spin_lock(&priv->lock);
 124
 125         /* Continue trying to always read if we should */
 126         if (!priv->throttled) {
 127                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 128                                   usb_rcvbulkpipe(priv->udev,
 129                                                   priv->bulk_address),
 130                                   priv->bulk_in_buffer, priv->buffer_size,
 131                                   opticon_bulk_callback, priv);
 132                 result = usb_submit_urb(port->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 opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 143 {
 144         struct opticon_private *priv = usb_get_serial_data(port->serial);
 145         unsigned long flags;
 146         int result = 0;
 147
 148         dbg("%s - port %d", __func__, port->number);
 149
 150         spin_lock_irqsave(&priv->lock, flags);
 151         priv->throttled = false;
 152         priv->actually_throttled = false;
 153         priv->port = port;
 154         spin_unlock_irqrestore(&priv->lock, flags);
 155
 156         /* Start reading from the device */
 157         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 158                           usb_rcvbulkpipe(priv->udev,
 159                                           priv->bulk_address),
 160                           priv->bulk_in_buffer, priv->buffer_size,
 161                           opticon_bulk_callback, priv);
 162         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 163         if (result)
 164                 dev_err(&port->dev,
 165                         "%s - failed resubmitting read urb, error %d\n",
 166                         __func__, result);
 167         return result;
 168 }
 169
 170 static void opticon_close(struct usb_serial_port *port)
 171 {
 172         struct opticon_private *priv = usb_get_serial_data(port->serial);
 173
 174         dbg("%s - port %d", __func__, port->number);
 175
 176         /* shutdown our urbs */
 177         usb_kill_urb(priv->bulk_read_urb);
 178 }
 179
 180 static void opticon_write_bulk_callback(struct urb *urb)
 181 {
 182         struct opticon_private *priv = urb->context;
 183         int status = urb->status;
 184         unsigned long flags;
 185
 186         /* free up the transfer buffer, as usb_free_urb() does not do this */
 187         kfree(urb->transfer_buffer);
 188
 189         if (status)
 190                 dbg("%s - nonzero write bulk status received: %d",
 191                     __func__, status);
 192
 193         spin_lock_irqsave(&priv->lock, flags);
 194         --priv->outstanding_urbs;
 195         spin_unlock_irqrestore(&priv->lock, flags);
 196
 197         usb_serial_port_softint(priv->port);
 198 }
 199
 200 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 201                          const unsigned char *buf, int count)
 202 {
 203         struct opticon_private *priv = usb_get_serial_data(port->serial);
 204         struct usb_serial *serial = port->serial;
 205         struct urb *urb;
 206         unsigned char *buffer;
 207         unsigned long flags;
 208         int status;
 209
 210         dbg("%s - port %d", __func__, port->number);
 211
 212         spin_lock_irqsave(&priv->lock, flags);
 213         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 214                 spin_unlock_irqrestore(&priv->lock, flags);
 215                 dbg("%s - write limit hit", __func__);
 216                 return 0;
 217         }
 218         priv->outstanding_urbs++;
 219         spin_unlock_irqrestore(&priv->lock, flags);
 220
 221         buffer = kmalloc(count, GFP_ATOMIC);
 222         if (!buffer) {
 223                 dev_err(&port->dev, "out of memory\n");
 224                 count = -ENOMEM;
 225                 goto error_no_buffer;
 226         }
 227
 228         urb = usb_alloc_urb(0, GFP_ATOMIC);
 229         if (!urb) {
 230                 dev_err(&port->dev, "no more free urbs\n");
 231                 count = -ENOMEM;
 232                 goto error_no_urb;
 233         }
 234
 235         memcpy(buffer, buf, count);
 236
 237         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 238
 239         usb_fill_bulk_urb(urb, serial->dev,
 240                           usb_sndbulkpipe(serial->dev,
 241                                           port->bulk_out_endpointAddress),
 242                           buffer, count, opticon_write_bulk_callback, priv);
 243
 244         /* send it down the pipe */
 245         status = usb_submit_urb(urb, GFP_ATOMIC);
 246         if (status) {
 247                 dev_err(&port->dev,
 248                    "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 249                                                         __func__, status);
 250                 count = status;
 251                 goto error;
 252         }
 253
 254         /* we are done with this urb, so let the host driver
 255          * really free it when it is finished with it */
 256         usb_free_urb(urb);
 257
 258         return count;
 259 error:
 260         usb_free_urb(urb);
 261 error_no_urb:
 262         kfree(buffer);
 263 error_no_buffer:
 264         spin_lock_irqsave(&priv->lock, flags);
 265         --priv->outstanding_urbs;
 266         spin_unlock_irqrestore(&priv->lock, flags);
 267         return count;
 268 }
 269
 270 static int opticon_write_room(struct tty_struct *tty)
 271 {
 272         struct usb_serial_port *port = tty->driver_data;
 273         struct opticon_private *priv = usb_get_serial_data(port->serial);
 274         unsigned long flags;
 275
 276         dbg("%s - port %d", __func__, port->number);
 277
 278         /*
 279          * We really can take almost anything the user throws at us
 280          * but let's pick a nice big number to tell the tty
 281          * layer that we have lots of free space, unless we don't.
 282          */
 283         spin_lock_irqsave(&priv->lock, flags);
 284         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 285                 spin_unlock_irqrestore(&priv->lock, flags);
 286                 dbg("%s - write limit hit", __func__);
 287                 return 0;
 288         }
 289         spin_unlock_irqrestore(&priv->lock, flags);
 290
 291         return 2048;
 292 }
 293
 294 static void opticon_throttle(struct tty_struct *tty)
 295 {
 296         struct usb_serial_port *port = tty->driver_data;
 297         struct opticon_private *priv = usb_get_serial_data(port->serial);
 298         unsigned long flags;
 299
 300         dbg("%s - port %d", __func__, port->number);
 301         spin_lock_irqsave(&priv->lock, flags);
 302         priv->throttled = true;
 303         spin_unlock_irqrestore(&priv->lock, flags);
 304 }
 305
 306
 307 static void opticon_unthrottle(struct tty_struct *tty)
 308 {
 309         struct usb_serial_port *port = tty->driver_data;
 310         struct opticon_private *priv = usb_get_serial_data(port->serial);
 311         unsigned long flags;
 312         int result, was_throttled;
 313
 314         dbg("%s - port %d", __func__, port->number);
 315
 316         spin_lock_irqsave(&priv->lock, flags);
 317         priv->throttled = false;
 318         was_throttled = priv->actually_throttled;
 319         priv->actually_throttled = false;
 320         spin_unlock_irqrestore(&priv->lock, flags);
 321
 322         priv->bulk_read_urb->dev = port->serial->dev;
 323         if (was_throttled) {
 324                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 325                 if (result)
 326                         dev_err(&port->dev,
 327                                 "%s - failed submitting read urb, error %d\n",
 328                                                         __func__, result);
 329         }
 330 }
 331
 332 static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
 333 {
 334         struct usb_serial_port *port = tty->driver_data;
 335         struct opticon_private *priv = usb_get_serial_data(port->serial);
 336         unsigned long flags;
 337         int result = 0;
 338
 339         dbg("%s - port %d", __func__, port->number);
 340
 341         spin_lock_irqsave(&priv->lock, flags);
 342         if (priv->rts)
 343                 result = TIOCM_RTS;
 344         spin_unlock_irqrestore(&priv->lock, flags);
 345
 346         dbg("%s - %x", __func__, result);
 347         return result;
 348 }
 349
 350 static int get_serial_info(struct opticon_private *priv,
 351                            struct serial_struct __user *serial)
 352 {
 353         struct serial_struct tmp;
 354
 355         if (!serial)
 356                 return -EFAULT;
 357
 358         memset(&tmp, 0x00, sizeof(tmp));
 359
 360         /* fake emulate a 16550 uart to make userspace code happy */
 361         tmp.type                = PORT_16550A;
 362         tmp.line                = priv->serial->minor;
 363         tmp.port                = 0;
 364         tmp.irq                 = 0;
 365         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 366         tmp.xmit_fifo_size      = 1024;
 367         tmp.baud_base           = 9600;
 368         tmp.close_delay         = 5*HZ;
 369         tmp.closing_wait        = 30*HZ;
 370
 371         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 372                 return -EFAULT;
 373         return 0;
 374 }
 375
 376 static int opticon_ioctl(struct tty_struct *tty, struct file *file,
 377                          unsigned int cmd, unsigned long arg)
 378 {
 379         struct usb_serial_port *port = tty->driver_data;
 380         struct opticon_private *priv = usb_get_serial_data(port->serial);
 381
 382         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 383
 384         switch (cmd) {
 385         case TIOCGSERIAL:
 386                 return get_serial_info(priv,
 387                                        (struct serial_struct __user *)arg);
 388         }
 389
 390         return -ENOIOCTLCMD;
 391 }
 392
 393 static int opticon_startup(struct usb_serial *serial)
 394 {
 395         struct opticon_private *priv;
 396         struct usb_host_interface *intf;
 397         int i;
 398         int retval = -ENOMEM;
 399         bool bulk_in_found = false;
 400
 401         /* create our private serial structure */
 402         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 403         if (priv == NULL) {
 404                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 405                 return -ENOMEM;
 406         }
 407         spin_lock_init(&priv->lock);
 408         priv->serial = serial;
 409         priv->port = serial->port[0];
 410         priv->udev = serial->dev;
 411
 412         /* find our bulk endpoint */
 413         intf = serial->interface->altsetting;
 414         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 415                 struct usb_endpoint_descriptor *endpoint;
 416
 417                 endpoint = &intf->endpoint[i].desc;
 418                 if (!usb_endpoint_is_bulk_in(endpoint))
 419                         continue;
 420
 421                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 422                 if (!priv->bulk_read_urb) {
 423                         dev_err(&priv->udev->dev, "out of memory\n");
 424                         goto error;
 425                 }
 426
 427                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 428                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 429                 if (!priv->bulk_in_buffer) {
 430                         dev_err(&priv->udev->dev, "out of memory\n");
 431                         goto error;
 432                 }
 433
 434                 priv->bulk_address = endpoint->bEndpointAddress;
 435
 436                 /* set up our bulk urb */
 437                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 438                                   usb_rcvbulkpipe(priv->udev,
 439                                                   endpoint->bEndpointAddress),
 440                                   priv->bulk_in_buffer, priv->buffer_size,
 441                                   opticon_bulk_callback, priv);
 442
 443                 bulk_in_found = true;
 444                 break;
 445                 }
 446
 447         if (!bulk_in_found) {
 448                 dev_err(&priv->udev->dev,
 449                         "Error - the proper endpoints were not found!\n");
 450                 goto error;
 451         }
 452
 453         usb_set_serial_data(serial, priv);
 454         return 0;
 455
 456 error:
 457         usb_free_urb(priv->bulk_read_urb);
 458         kfree(priv->bulk_in_buffer);
 459         kfree(priv);
 460         return retval;
 461 }
 462
 463 static void opticon_disconnect(struct usb_serial *serial)
 464 {
 465         struct opticon_private *priv = usb_get_serial_data(serial);
 466
 467         dbg("%s", __func__);
 468
 469         usb_kill_urb(priv->bulk_read_urb);
 470         usb_free_urb(priv->bulk_read_urb);
 471 }
 472
 473 static void opticon_release(struct usb_serial *serial)
 474 {
 475         struct opticon_private *priv = usb_get_serial_data(serial);
 476
 477         dbg("%s", __func__);
 478
 479         kfree(priv->bulk_in_buffer);
 480         kfree(priv);
 481 }
 482
 483 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 484 {
 485         struct usb_serial *serial = usb_get_intfdata(intf);
 486         struct opticon_private *priv = usb_get_serial_data(serial);
 487
 488         usb_kill_urb(priv->bulk_read_urb);
 489         return 0;
 490 }
 491
 492 static int opticon_resume(struct usb_interface *intf)
 493 {
 494         struct usb_serial *serial = usb_get_intfdata(intf);
 495         struct opticon_private *priv = usb_get_serial_data(serial);
 496         struct usb_serial_port *port = serial->port[0];
 497         int result;
 498
 499         mutex_lock(&port->port.mutex);
 500         /* This is protected by the port mutex against close/open */
 501         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 502                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 503         else
 504                 result = 0;
 505         mutex_unlock(&port->port.mutex);
 506         return result;
 507 }
 508
 509 static struct usb_driver opticon_driver = {
 510         .name =         "opticon",
 511         .probe =        usb_serial_probe,
 512         .disconnect =   usb_serial_disconnect,
 513         .suspend =      opticon_suspend,
 514         .resume =       opticon_resume,
 515         .id_table =     id_table,
 516         .no_dynamic_id =        1,
 517 };
 518
 519 static struct usb_serial_driver opticon_device = {
 520         .driver = {
 521                 .owner =        THIS_MODULE,
 522                 .name =         "opticon",
 523         },
 524         .id_table =             id_table,
 525         .usb_driver =           &opticon_driver,
 526         .num_ports =            1,
 527         .attach =               opticon_startup,
 528         .open =                 opticon_open,
 529         .close =                opticon_close,
 530         .write =                opticon_write,
 531         .write_room =           opticon_write_room,
 532         .disconnect =           opticon_disconnect,
 533         .release =              opticon_release,
 534         .throttle =             opticon_throttle,
 535         .unthrottle =           opticon_unthrottle,
 536         .ioctl =                opticon_ioctl,
 537         .tiocmget =             opticon_tiocmget,
 538 };
 539
 540 static int __init opticon_init(void)
 541 {
 542         int retval;
 543
 544         retval = usb_serial_register(&opticon_device);
 545         if (retval)
 546                 return retval;
 547         retval = usb_register(&opticon_driver);
 548         if (retval)
 549                 usb_serial_deregister(&opticon_device);
 550         return retval;
 551 }
 552
 553 static void __exit opticon_exit(void)
 554 {
 555         usb_deregister(&opticon_driver);
 556         usb_serial_deregister(&opticon_device);
 557 }
 558
 559 module_init(opticon_init);
 560 module_exit(opticon_exit);
 561 MODULE_LICENSE("GPL");
 562
 563 module_param(debug, bool, S_IRUGO | S_IWUSR);
 564 MODULE_PARM_DESC(debug, "Debug enabled or not");