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