drivers/usb/serial/opticon.c

   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 usb_serial_port *port;
  44         unsigned char *bulk_in_buffer;
  45         struct urb *bulk_read_urb;
  46         int buffer_size;
  47         u8 bulk_address;
  48         spinlock_t lock;        /* protects the following flags */
  49         bool throttled;
  50         bool actually_throttled;
  51         bool rts;
  52         bool cts;
  53         int outstanding_urbs;
  54 };
  55
  56
  57
  58 static void opticon_read_bulk_callback(struct urb *urb)
  59 {
  60         struct opticon_private *priv = urb->context;
  61         unsigned char *data = urb->transfer_buffer;
  62         struct usb_serial_port *port = priv->port;
  63         int status = urb->status;
  64         struct tty_struct *tty;
  65         int result;
  66         int data_length;
  67         unsigned long flags;
  68
  69         switch (status) {
  70         case 0:
  71                 /* success */
  72                 break;
  73         case -ECONNRESET:
  74         case -ENOENT:
  75         case -ESHUTDOWN:
  76                 /* this urb is terminated, clean up */
  77                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  78                         __func__, status);
  79                 return;
  80         default:
  81                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  82                         __func__, status);
  83                 goto exit;
  84         }
  85
  86         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
  87
  88         if (urb->actual_length > 2) {
  89                 data_length = urb->actual_length - 2;
  90
  91                 /*
  92                  * Data from the device comes with a 2 byte header:
  93                  *
  94                  * <0x00><0x00>data...
  95                  *      This is real data to be sent to the tty layer
  96                  * <0x00><0x01)level
  97                  *      This is a CTS level change, the third byte is the CTS
  98                  *      value (0 for low, 1 for high).
  99                  */
 100                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
 101                         /* real data, send it to the tty layer */
 102                         tty = tty_port_tty_get(&port->port);
 103                         if (tty) {
 104                                 tty_insert_flip_string(tty, data + 2,
 105                                                        data_length);
 106                                 tty_flip_buffer_push(tty);
 107                                 tty_kref_put(tty);
 108                         }
 109                 } else {
 110                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 111                                 spin_lock_irqsave(&priv->lock, flags);
 112                                 /* CTS status information package */
 113                                 if (data[2] == 0x00)
 114                                         priv->cts = false;
 115                                 else
 116                                         priv->cts = true;
 117                                 spin_unlock_irqrestore(&priv->lock, flags);
 118                         } else {
 119                                 dev_dbg(&port->dev,
 120                                         "Unknown data packet received from the device:"
 121                                         " %2x %2x\n",
 122                                         data[0], data[1]);
 123                         }
 124                 }
 125         } else {
 126                 dev_dbg(&port->dev,
 127                         "Improper amount of data received from the device, "
 128                         "%d bytes", urb->actual_length);
 129         }
 130
 131 exit:
 132         spin_lock(&priv->lock);
 133
 134         /* Continue trying to always read if we should */
 135         if (!priv->throttled) {
 136                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 137                 if (result)
 138                         dev_err(&port->dev,
 139                             "%s - failed resubmitting read urb, error %d\n",
 140                                                         __func__, result);
 141         } else
 142                 priv->actually_throttled = true;
 143         spin_unlock(&priv->lock);
 144 }
 145
 146 static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 147                                 u8 val)
 148 {
 149         struct usb_serial *serial = port->serial;
 150         int retval;
 151         u8 *buffer;
 152
 153         buffer = kzalloc(1, GFP_KERNEL);
 154         if (!buffer)
 155                 return -ENOMEM;
 156
 157         buffer[0] = val;
 158         /* Send the message to the vendor control endpoint
 159          * of the connected device */
 160         retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 161                                 requesttype,
 162                                 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 163                                 0, 0, buffer, 1, 0);
 164         kfree(buffer);
 165
 166         return retval;
 167 }
 168
 169 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 170 {
 171         struct opticon_private *priv = usb_get_serial_data(port->serial);
 172         unsigned long flags;
 173         int result = 0;
 174
 175         spin_lock_irqsave(&priv->lock, flags);
 176         priv->throttled = false;
 177         priv->actually_throttled = false;
 178         priv->port = port;
 179         priv->rts = false;
 180         spin_unlock_irqrestore(&priv->lock, flags);
 181
 182         /* Clear RTS line */
 183         send_control_msg(port, CONTROL_RTS, 0);
 184
 185         /* clear the halt status of the enpoint */
 186         usb_clear_halt(port->serial->dev, priv->bulk_read_urb->pipe);
 187
 188         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 189         if (result)
 190                 dev_err(&port->dev,
 191                         "%s - failed resubmitting read urb, error %d\n",
 192                         __func__, result);
 193         /* Request CTS line state, sometimes during opening the current
 194          * CTS state can be missed. */
 195         send_control_msg(port, RESEND_CTS_STATE, 1);
 196         return result;
 197 }
 198
 199 static void opticon_close(struct usb_serial_port *port)
 200 {
 201         struct opticon_private *priv = usb_get_serial_data(port->serial);
 202
 203         /* shutdown our urbs */
 204         usb_kill_urb(priv->bulk_read_urb);
 205 }
 206
 207 static void opticon_write_control_callback(struct urb *urb)
 208 {
 209         struct opticon_private *priv = urb->context;
 210         int status = urb->status;
 211         unsigned long flags;
 212
 213         /* free up the transfer buffer, as usb_free_urb() does not do this */
 214         kfree(urb->transfer_buffer);
 215
 216         /* setup packet may be set if we're using it for writing */
 217         kfree(urb->setup_packet);
 218
 219         if (status)
 220                 dev_dbg(&priv->port->dev,
 221                         "%s - non-zero urb status received: %d\n",
 222                         __func__, status);
 223
 224         spin_lock_irqsave(&priv->lock, flags);
 225         --priv->outstanding_urbs;
 226         spin_unlock_irqrestore(&priv->lock, flags);
 227
 228         usb_serial_port_softint(priv->port);
 229 }
 230
 231 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 232                          const unsigned char *buf, int count)
 233 {
 234         struct opticon_private *priv = usb_get_serial_data(port->serial);
 235         struct usb_serial *serial = port->serial;
 236         struct urb *urb;
 237         unsigned char *buffer;
 238         unsigned long flags;
 239         int status;
 240         struct usb_ctrlrequest *dr;
 241
 242         spin_lock_irqsave(&priv->lock, flags);
 243         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 244                 spin_unlock_irqrestore(&priv->lock, flags);
 245                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 246                 return 0;
 247         }
 248         priv->outstanding_urbs++;
 249         spin_unlock_irqrestore(&priv->lock, flags);
 250
 251         buffer = kmalloc(count, GFP_ATOMIC);
 252         if (!buffer) {
 253                 dev_err(&port->dev, "out of memory\n");
 254                 count = -ENOMEM;
 255
 256                 goto error_no_buffer;
 257         }
 258
 259         urb = usb_alloc_urb(0, GFP_ATOMIC);
 260         if (!urb) {
 261                 dev_err(&port->dev, "no more free urbs\n");
 262                 count = -ENOMEM;
 263                 goto error_no_urb;
 264         }
 265
 266         memcpy(buffer, buf, count);
 267
 268         usb_serial_debug_data(&port->dev, __func__, count, buffer);
 269
 270         /* The conncected devices do not have a bulk write endpoint,
 271          * to transmit data to de barcode device the control endpoint is used */
 272         dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 273         if (!dr) {
 274                 dev_err(&port->dev, "out of memory\n");
 275                 count = -ENOMEM;
 276                 goto error_no_dr;
 277         }
 278
 279         dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 280         dr->bRequest = 0x01;
 281         dr->wValue = 0;
 282         dr->wIndex = 0;
 283         dr->wLength = cpu_to_le16(count);
 284
 285         usb_fill_control_urb(urb, serial->dev,
 286                 usb_sndctrlpipe(serial->dev, 0),
 287                 (unsigned char *)dr, buffer, count,
 288                 opticon_write_control_callback, priv);
 289
 290         /* send it down the pipe */
 291         status = usb_submit_urb(urb, GFP_ATOMIC);
 292         if (status) {
 293                 dev_err(&port->dev,
 294                 "%s - usb_submit_urb(write endpoint) failed status = %d\n",
 295                                                         __func__, status);
 296                 count = status;
 297                 goto error;
 298         }
 299
 300         /* we are done with this urb, so let the host driver
 301          * really free it when it is finished with it */
 302         usb_free_urb(urb);
 303
 304         return count;
 305 error:
 306         kfree(dr);
 307 error_no_dr:
 308         usb_free_urb(urb);
 309 error_no_urb:
 310         kfree(buffer);
 311 error_no_buffer:
 312         spin_lock_irqsave(&priv->lock, flags);
 313         --priv->outstanding_urbs;
 314         spin_unlock_irqrestore(&priv->lock, flags);
 315         return count;
 316 }
 317
 318 static int opticon_write_room(struct tty_struct *tty)
 319 {
 320         struct usb_serial_port *port = tty->driver_data;
 321         struct opticon_private *priv = usb_get_serial_data(port->serial);
 322         unsigned long flags;
 323
 324         /*
 325          * We really can take almost anything the user throws at us
 326          * but let's pick a nice big number to tell the tty
 327          * layer that we have lots of free space, unless we don't.
 328          */
 329         spin_lock_irqsave(&priv->lock, flags);
 330         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 331                 spin_unlock_irqrestore(&priv->lock, flags);
 332                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 333                 return 0;
 334         }
 335         spin_unlock_irqrestore(&priv->lock, flags);
 336
 337         return 2048;
 338 }
 339
 340 static void opticon_throttle(struct tty_struct *tty)
 341 {
 342         struct usb_serial_port *port = tty->driver_data;
 343         struct opticon_private *priv = usb_get_serial_data(port->serial);
 344         unsigned long flags;
 345
 346         spin_lock_irqsave(&priv->lock, flags);
 347         priv->throttled = true;
 348         spin_unlock_irqrestore(&priv->lock, flags);
 349 }
 350
 351
 352 static void opticon_unthrottle(struct tty_struct *tty)
 353 {
 354         struct usb_serial_port *port = tty->driver_data;
 355         struct opticon_private *priv = usb_get_serial_data(port->serial);
 356         unsigned long flags;
 357         int result, was_throttled;
 358
 359         spin_lock_irqsave(&priv->lock, flags);
 360         priv->throttled = false;
 361         was_throttled = priv->actually_throttled;
 362         priv->actually_throttled = false;
 363         spin_unlock_irqrestore(&priv->lock, flags);
 364
 365         if (was_throttled) {
 366                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 367                 if (result)
 368                         dev_err(&port->dev,
 369                                 "%s - failed submitting read urb, error %d\n",
 370                                                         __func__, result);
 371         }
 372 }
 373
 374 static int opticon_tiocmget(struct tty_struct *tty)
 375 {
 376         struct usb_serial_port *port = tty->driver_data;
 377         struct opticon_private *priv = usb_get_serial_data(port->serial);
 378         unsigned long flags;
 379         int result = 0;
 380
 381         spin_lock_irqsave(&priv->lock, flags);
 382         if (priv->rts)
 383                 result |= TIOCM_RTS;
 384         if (priv->cts)
 385                 result |= TIOCM_CTS;
 386         spin_unlock_irqrestore(&priv->lock, flags);
 387
 388         dev_dbg(&port->dev, "%s - %x\n", __func__, result);
 389         return result;
 390 }
 391
 392 static int opticon_tiocmset(struct tty_struct *tty,
 393                            unsigned int set, unsigned int clear)
 394 {
 395         struct usb_serial_port *port = tty->driver_data;
 396         struct usb_serial *serial = port->serial;
 397         struct opticon_private *priv = usb_get_serial_data(port->serial);
 398         unsigned long flags;
 399         bool rts;
 400         bool changed = false;
 401         int ret;
 402
 403         /* We only support RTS so we only handle that */
 404         spin_lock_irqsave(&priv->lock, flags);
 405
 406         rts = priv->rts;
 407         if (set & TIOCM_RTS)
 408                 priv->rts = true;
 409         if (clear & TIOCM_RTS)
 410                 priv->rts = false;
 411         changed = rts ^ priv->rts;
 412         spin_unlock_irqrestore(&priv->lock, flags);
 413
 414         if (!changed)
 415                 return 0;
 416
 417         /* Send the new RTS state to the connected device */
 418         mutex_lock(&serial->disc_mutex);
 419         if (!serial->disconnected)
 420                 ret = send_control_msg(port, CONTROL_RTS, !rts);
 421         else
 422                 ret = -ENODEV;
 423         mutex_unlock(&serial->disc_mutex);
 424
 425         return ret;
 426 }
 427
 428 static int get_serial_info(struct opticon_private *priv,
 429                            struct serial_struct __user *serial)
 430 {
 431         struct serial_struct tmp;
 432
 433         if (!serial)
 434                 return -EFAULT;
 435
 436         memset(&tmp, 0x00, sizeof(tmp));
 437
 438         /* fake emulate a 16550 uart to make userspace code happy */
 439         tmp.type                = PORT_16550A;
 440         tmp.line                = priv->port->serial->minor;
 441         tmp.port                = 0;
 442         tmp.irq                 = 0;
 443         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 444         tmp.xmit_fifo_size      = 1024;
 445         tmp.baud_base           = 9600;
 446         tmp.close_delay         = 5*HZ;
 447         tmp.closing_wait        = 30*HZ;
 448
 449         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 450                 return -EFAULT;
 451         return 0;
 452 }
 453
 454 static int opticon_ioctl(struct tty_struct *tty,
 455                          unsigned int cmd, unsigned long arg)
 456 {
 457         struct usb_serial_port *port = tty->driver_data;
 458         struct opticon_private *priv = usb_get_serial_data(port->serial);
 459
 460         dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
 461
 462         switch (cmd) {
 463         case TIOCGSERIAL:
 464                 return get_serial_info(priv,
 465                                        (struct serial_struct __user *)arg);
 466         }
 467
 468         return -ENOIOCTLCMD;
 469 }
 470
 471 static int opticon_startup(struct usb_serial *serial)
 472 {
 473         struct opticon_private *priv;
 474         int retval = -ENOMEM;
 475
 476         if (!serial->num_bulk_in) {
 477                 dev_err(&serial->dev->dev, "no bulk in endpoint\n");
 478                 return -ENODEV;
 479         }
 480
 481         /* create our private serial structure */
 482         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 483         if (priv == NULL) {
 484                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 485                 return -ENOMEM;
 486         }
 487         spin_lock_init(&priv->lock);
 488         priv->port = serial->port[0];
 489
 490         priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 491         if (!priv->bulk_read_urb) {
 492                 dev_err(&serial->dev->dev, "out of memory\n");
 493                 goto error;
 494         }
 495
 496         priv->buffer_size = 2 * priv->port->bulk_in_size;
 497         priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 498         if (!priv->bulk_in_buffer) {
 499                 dev_err(&serial->dev->dev, "out of memory\n");
 500                 goto error;
 501         }
 502
 503         priv->bulk_address = priv->port->bulk_in_endpointAddress;
 504
 505         usb_fill_bulk_urb(priv->bulk_read_urb, serial->dev,
 506                                 usb_rcvbulkpipe(serial->dev,
 507                                                 priv->bulk_address),
 508                                 priv->bulk_in_buffer, priv->buffer_size,
 509                                 opticon_read_bulk_callback, priv);
 510
 511         usb_set_serial_data(serial, priv);
 512         return 0;
 513
 514 error:
 515         usb_free_urb(priv->bulk_read_urb);
 516         kfree(priv->bulk_in_buffer);
 517         kfree(priv);
 518         return retval;
 519 }
 520
 521 static void opticon_disconnect(struct usb_serial *serial)
 522 {
 523         struct opticon_private *priv = usb_get_serial_data(serial);
 524
 525         usb_kill_urb(priv->bulk_read_urb);
 526 }
 527
 528 static void opticon_release(struct usb_serial *serial)
 529 {
 530         struct opticon_private *priv = usb_get_serial_data(serial);
 531
 532         usb_free_urb(priv->bulk_read_urb);
 533         kfree(priv->bulk_in_buffer);
 534         kfree(priv);
 535 }
 536
 537 static int opticon_suspend(struct usb_serial *serial, pm_message_t message)
 538 {
 539         struct opticon_private *priv = usb_get_serial_data(serial);
 540
 541         usb_kill_urb(priv->bulk_read_urb);
 542         return 0;
 543 }
 544
 545 static int opticon_resume(struct usb_serial *serial)
 546 {
 547         struct opticon_private *priv = usb_get_serial_data(serial);
 548         struct usb_serial_port *port = serial->port[0];
 549         int result;
 550
 551         mutex_lock(&port->port.mutex);
 552         /* This is protected by the port mutex against close/open */
 553         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 554                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 555         else
 556                 result = 0;
 557         mutex_unlock(&port->port.mutex);
 558         return result;
 559 }
 560
 561 static struct usb_serial_driver opticon_device = {
 562         .driver = {
 563                 .owner =        THIS_MODULE,
 564                 .name =         "opticon",
 565         },
 566         .id_table =             id_table,
 567         .num_ports =            1,
 568         .attach =               opticon_startup,
 569         .open =                 opticon_open,
 570         .close =                opticon_close,
 571         .write =                opticon_write,
 572         .write_room =           opticon_write_room,
 573         .disconnect =           opticon_disconnect,
 574         .release =              opticon_release,
 575         .throttle =             opticon_throttle,
 576         .unthrottle =           opticon_unthrottle,
 577         .ioctl =                opticon_ioctl,
 578         .tiocmget =             opticon_tiocmget,
 579         .tiocmset =             opticon_tiocmset,
 580         .suspend =              opticon_suspend,
 581         .resume =               opticon_resume,
 582 };
 583
 584 static struct usb_serial_driver * const serial_drivers[] = {
 585         &opticon_device, NULL
 586 };
 587
 588 module_usb_serial_driver(serial_drivers, id_table);
 589
 590 MODULE_DESCRIPTION(DRIVER_DESC);
 591 MODULE_LICENSE("GPL");