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