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 {
 149         struct opticon_private *priv = usb_get_serial_data(port->serial);
 150         unsigned long flags;
 151         int result = 0;
 152
 153         dbg("%s - port %d", __func__, port->number);
 154
 155         spin_lock_irqsave(&priv->lock, flags);
 156         priv->throttled = false;
 157         priv->actually_throttled = false;
 158         priv->port = port;
 159         spin_unlock_irqrestore(&priv->lock, flags);
 160
 161         /* Start reading from the device */
 162         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 163                           usb_rcvbulkpipe(priv->udev,
 164                                           priv->bulk_address),
 165                           priv->bulk_in_buffer, priv->buffer_size,
 166                           opticon_bulk_callback, priv);
 167         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 168         if (result)
 169                 dev_err(&port->dev,
 170                         "%s - failed resubmitting read urb, error %d\n",
 171                         __func__, result);
 172         return result;
 173 }
 174
 175 static void opticon_close(struct usb_serial_port *port)
 176 {
 177         struct opticon_private *priv = usb_get_serial_data(port->serial);
 178
 179         dbg("%s - port %d", __func__, port->number);
 180
 181         /* shutdown our urbs */
 182         usb_kill_urb(priv->bulk_read_urb);
 183 }
 184
 185 static void opticon_write_bulk_callback(struct urb *urb)
 186 {
 187         struct opticon_private *priv = urb->context;
 188         int status = urb->status;
 189         unsigned long flags;
 190
 191         /* free up the transfer buffer, as usb_free_urb() does not do this */
 192         kfree(urb->transfer_buffer);
 193
 194         if (status)
 195                 dbg("%s - nonzero write bulk status received: %d",
 196                     __func__, status);
 197
 198         spin_lock_irqsave(&priv->lock, flags);
 199         --priv->outstanding_urbs;
 200         spin_unlock_irqrestore(&priv->lock, flags);
 201
 202         usb_serial_port_softint(priv->port);
 203 }
 204
 205 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 206                          const unsigned char *buf, int count)
 207 {
 208         struct opticon_private *priv = usb_get_serial_data(port->serial);
 209         struct usb_serial *serial = port->serial;
 210         struct urb *urb;
 211         unsigned char *buffer;
 212         unsigned long flags;
 213         int status;
 214
 215         dbg("%s - port %d", __func__, port->number);
 216
 217         spin_lock_irqsave(&priv->lock, flags);
 218         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 219                 spin_unlock_irqrestore(&priv->lock, flags);
 220                 dbg("%s - write limit hit\n", __func__);
 221                 return 0;
 222         }
 223         priv->outstanding_urbs++;
 224         spin_unlock_irqrestore(&priv->lock, flags);
 225
 226         buffer = kmalloc(count, GFP_ATOMIC);
 227         if (!buffer) {
 228                 dev_err(&port->dev, "out of memory\n");
 229                 count = -ENOMEM;
 230                 goto error_no_buffer;
 231         }
 232
 233         urb = usb_alloc_urb(0, GFP_ATOMIC);
 234         if (!urb) {
 235                 dev_err(&port->dev, "no more free urbs\n");
 236                 count = -ENOMEM;
 237                 goto error_no_urb;
 238         }
 239
 240         memcpy(buffer, buf, count);
 241
 242         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 243
 244         usb_fill_bulk_urb(urb, serial->dev,
 245                           usb_sndbulkpipe(serial->dev,
 246                                           port->bulk_out_endpointAddress),
 247                           buffer, count, opticon_write_bulk_callback, priv);
 248
 249         /* send it down the pipe */
 250         status = usb_submit_urb(urb, GFP_ATOMIC);
 251         if (status) {
 252                 dev_err(&port->dev,
 253                    "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 254                                                         __func__, status);
 255                 count = status;
 256                 goto error;
 257         }
 258
 259         /* we are done with this urb, so let the host driver
 260          * really free it when it is finished with it */
 261         usb_free_urb(urb);
 262
 263         return count;
 264 error:
 265         usb_free_urb(urb);
 266 error_no_urb:
 267         kfree(buffer);
 268 error_no_buffer:
 269         spin_lock_irqsave(&priv->lock, flags);
 270         --priv->outstanding_urbs;
 271         spin_unlock_irqrestore(&priv->lock, flags);
 272         return count;
 273 }
 274
 275 static int opticon_write_room(struct tty_struct *tty)
 276 {
 277         struct usb_serial_port *port = tty->driver_data;
 278         struct opticon_private *priv = usb_get_serial_data(port->serial);
 279         unsigned long flags;
 280
 281         dbg("%s - port %d", __func__, port->number);
 282
 283         /*
 284          * We really can take almost anything the user throws at us
 285          * but let's pick a nice big number to tell the tty
 286          * layer that we have lots of free space, unless we don't.
 287          */
 288         spin_lock_irqsave(&priv->lock, flags);
 289         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 290                 spin_unlock_irqrestore(&priv->lock, flags);
 291                 dbg("%s - write limit hit\n", __func__);
 292                 return 0;
 293         }
 294         spin_unlock_irqrestore(&priv->lock, flags);
 295
 296         return 2048;
 297 }
 298
 299 static void opticon_throttle(struct tty_struct *tty)
 300 {
 301         struct usb_serial_port *port = tty->driver_data;
 302         struct opticon_private *priv = usb_get_serial_data(port->serial);
 303         unsigned long flags;
 304
 305         dbg("%s - port %d", __func__, port->number);
 306         spin_lock_irqsave(&priv->lock, flags);
 307         priv->throttled = true;
 308         spin_unlock_irqrestore(&priv->lock, flags);
 309 }
 310
 311
 312 static void opticon_unthrottle(struct tty_struct *tty)
 313 {
 314         struct usb_serial_port *port = tty->driver_data;
 315         struct opticon_private *priv = usb_get_serial_data(port->serial);
 316         unsigned long flags;
 317         int result;
 318
 319         dbg("%s - port %d", __func__, port->number);
 320
 321         spin_lock_irqsave(&priv->lock, flags);
 322         priv->throttled = false;
 323         priv->actually_throttled = false;
 324         spin_unlock_irqrestore(&priv->lock, flags);
 325
 326         priv->bulk_read_urb->dev = port->serial->dev;
 327         result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 328         if (result)
 329                 dev_err(&port->dev,
 330                         "%s - failed submitting read urb, error %d\n",
 331                                                         __func__, result);
 332 }
 333
 334 static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
 335 {
 336         struct usb_serial_port *port = tty->driver_data;
 337         struct opticon_private *priv = usb_get_serial_data(port->serial);
 338         unsigned long flags;
 339         int result = 0;
 340
 341         dbg("%s - port %d", __func__, port->number);
 342
 343         spin_lock_irqsave(&priv->lock, flags);
 344         if (priv->rts)
 345                 result = TIOCM_RTS;
 346         spin_unlock_irqrestore(&priv->lock, flags);
 347
 348         dbg("%s - %x", __func__, result);
 349         return result;
 350 }
 351
 352 static int get_serial_info(struct opticon_private *priv,
 353                            struct serial_struct __user *serial)
 354 {
 355         struct serial_struct tmp;
 356
 357         if (!serial)
 358                 return -EFAULT;
 359
 360         memset(&tmp, 0x00, sizeof(tmp));
 361
 362         /* fake emulate a 16550 uart to make userspace code happy */
 363         tmp.type                = PORT_16550A;
 364         tmp.line                = priv->serial->minor;
 365         tmp.port                = 0;
 366         tmp.irq                 = 0;
 367         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 368         tmp.xmit_fifo_size      = 1024;
 369         tmp.baud_base           = 9600;
 370         tmp.close_delay         = 5*HZ;
 371         tmp.closing_wait        = 30*HZ;
 372
 373         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 374                 return -EFAULT;
 375         return 0;
 376 }
 377
 378 static int opticon_ioctl(struct tty_struct *tty, struct file *file,
 379                          unsigned int cmd, unsigned long arg)
 380 {
 381         struct usb_serial_port *port = tty->driver_data;
 382         struct opticon_private *priv = usb_get_serial_data(port->serial);
 383
 384         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 385
 386         switch (cmd) {
 387         case TIOCGSERIAL:
 388                 return get_serial_info(priv,
 389                                        (struct serial_struct __user *)arg);
 390         }
 391
 392         return -ENOIOCTLCMD;
 393 }
 394
 395 static int opticon_startup(struct usb_serial *serial)
 396 {
 397         struct opticon_private *priv;
 398         struct usb_host_interface *intf;
 399         int i;
 400         int retval = -ENOMEM;
 401         bool bulk_in_found = false;
 402
 403         /* create our private serial structure */
 404         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 405         if (priv == NULL) {
 406                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 407                 return -ENOMEM;
 408         }
 409         spin_lock_init(&priv->lock);
 410         priv->serial = serial;
 411         priv->port = serial->port[0];
 412         priv->udev = serial->dev;
 413
 414         /* find our bulk endpoint */
 415         intf = serial->interface->altsetting;
 416         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 417                 struct usb_endpoint_descriptor *endpoint;
 418
 419                 endpoint = &intf->endpoint[i].desc;
 420                 if (!usb_endpoint_is_bulk_in(endpoint))
 421                         continue;
 422
 423                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 424                 if (!priv->bulk_read_urb) {
 425                         dev_err(&priv->udev->dev, "out of memory\n");
 426                         goto error;
 427                 }
 428
 429                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 430                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 431                 if (!priv->bulk_in_buffer) {
 432                         dev_err(&priv->udev->dev, "out of memory\n");
 433                         goto error;
 434                 }
 435
 436                 priv->bulk_address = endpoint->bEndpointAddress;
 437
 438                 /* set up our bulk urb */
 439                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 440                                   usb_rcvbulkpipe(priv->udev,
 441                                                   endpoint->bEndpointAddress),
 442                                   priv->bulk_in_buffer, priv->buffer_size,
 443                                   opticon_bulk_callback, priv);
 444
 445                 bulk_in_found = true;
 446                 break;
 447                 }
 448
 449         if (!bulk_in_found) {
 450                 dev_err(&priv->udev->dev,
 451                         "Error - the proper endpoints were not found!\n");
 452                 goto error;
 453         }
 454
 455         usb_set_serial_data(serial, priv);
 456         return 0;
 457
 458 error:
 459         usb_free_urb(priv->bulk_read_urb);
 460         kfree(priv->bulk_in_buffer);
 461         kfree(priv);
 462         return retval;
 463 }
 464
 465 static void opticon_disconnect(struct usb_serial *serial)
 466 {
 467         struct opticon_private *priv = usb_get_serial_data(serial);
 468
 469         dbg("%s", __func__);
 470
 471         usb_kill_urb(priv->bulk_read_urb);
 472         usb_free_urb(priv->bulk_read_urb);
 473 }
 474
 475 static void opticon_release(struct usb_serial *serial)
 476 {
 477         struct opticon_private *priv = usb_get_serial_data(serial);
 478
 479         dbg("%s", __func__);
 480
 481         kfree(priv->bulk_in_buffer);
 482         kfree(priv);
 483 }
 484
 485 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 486 {
 487         struct usb_serial *serial = usb_get_intfdata(intf);
 488         struct opticon_private *priv = usb_get_serial_data(serial);
 489
 490         usb_kill_urb(priv->bulk_read_urb);
 491         return 0;
 492 }
 493
 494 static int opticon_resume(struct usb_interface *intf)
 495 {
 496         struct usb_serial *serial = usb_get_intfdata(intf);
 497         struct opticon_private *priv = usb_get_serial_data(serial);
 498         struct usb_serial_port *port = serial->port[0];
 499         int result;
 500
 501         mutex_lock(&port->mutex);
 502         if (port->port.count)
 503                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 504         else
 505                 result = 0;
 506         mutex_unlock(&port->mutex);
 507         return result;
 508 }
 509
 510 static struct usb_driver opticon_driver = {
 511         .name =         "opticon",
 512         .probe =        usb_serial_probe,
 513         .disconnect =   usb_serial_disconnect,
 514         .suspend =      opticon_suspend,
 515         .resume =       opticon_resume,
 516         .id_table =     id_table,
 517         .no_dynamic_id =        1,
 518 };
 519
 520 static struct usb_serial_driver opticon_device = {
 521         .driver = {
 522                 .owner =        THIS_MODULE,
 523                 .name =         "opticon",
 524         },
 525         .id_table =             id_table,
 526         .usb_driver =           &opticon_driver,
 527         .num_ports =            1,
 528         .attach =               opticon_startup,
 529         .open =                 opticon_open,
 530         .close =                opticon_close,
 531         .write =                opticon_write,
 532         .write_room =           opticon_write_room,
 533         .disconnect =           opticon_disconnect,
 534         .release =              opticon_release,
 535         .throttle =             opticon_throttle,
 536         .unthrottle =           opticon_unthrottle,
 537         .ioctl =                opticon_ioctl,
 538         .tiocmget =             opticon_tiocmget,
 539 };
 540
 541 static int __init opticon_init(void)
 542 {
 543         int retval;
 544
 545         retval = usb_serial_register(&opticon_device);
 546         if (retval)
 547                 return retval;
 548         retval = usb_register(&opticon_driver);
 549         if (retval)
 550                 usb_serial_deregister(&opticon_device);
 551         return retval;
 552 }
 553
 554 static void __exit opticon_exit(void)
 555 {
 556         usb_deregister(&opticon_driver);
 557         usb_serial_deregister(&opticon_device);
 558 }
 559
 560 module_init(opticon_init);
 561 module_exit(opticon_exit);
 562 MODULE_LICENSE("GPL");
 563
 564 module_param(debug, bool, S_IRUGO | S_IWUSR);
 565 MODULE_PARM_DESC(debug, "Debug enabled or not");