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   1 /*
   2  * USB Empeg empeg-car player driver
   3  *
   4  *      Copyright (C) 2000, 2001
   5  *          Gary Brubaker (xavyer@ix.netcom.com)
   6  *
   7  *      Copyright (C) 1999 - 2001
   8  *          Greg Kroah-Hartman (greg@kroah.com)
   9  *
  10  *      This program is free software; you can redistribute it and/or modify
  11  *      it under the terms of the GNU General Public License, as published by
  12  *      the Free Software Foundation, version 2.
  13  *
  14  * See Documentation/usb/usb-serial.txt for more information on using this driver
  15  *
  16  * (07/16/2001) gb
  17  *      remove unused code in empeg_close() (thanks to Oliver Neukum for pointing this
  18  *      out) and rewrote empeg_set_termios().
  19  *
  20  * (05/30/2001) gkh
  21  *      switched from using spinlock to a semaphore, which fixes lots of problems.
  22  *
  23  * (04/08/2001) gb
  24  *      Identify version on module load.
  25  *
  26  * (01/22/2001) gb
  27  *      Added write_room() and chars_in_buffer() support.
  28  *
  29  * (12/21/2000) gb
  30  *      Moved termio stuff inside the port->active check.
  31  *      Moved MOD_DEC_USE_COUNT to end of empeg_close().
  32  *
  33  * (12/03/2000) gb
  34  *      Added port->tty->ldisc.set_termios(port->tty, NULL) to empeg_open()
  35  *      This notifies the tty driver that the termios have changed.
  36  *
  37  * (11/13/2000) gb
  38  *      Moved tty->low_latency = 1 from empeg_read_bulk_callback() to empeg_open()
  39  *      (It only needs to be set once - Doh!)
  40  *
  41  * (11/11/2000) gb
  42  *      Updated to work with id_table structure.
  43  *
  44  * (11/04/2000) gb
  45  *      Forked this from visor.c, and hacked it up to work with an
  46  *      Empeg ltd. empeg-car player.  Constructive criticism welcomed.
  47  *      I would like to say, 'Thank You' to Greg Kroah-Hartman for the
  48  *      use of his code, and for his guidance, advice and patience. :)
  49  *      A 'Thank You' is in order for John Ripley of Empeg ltd for his
  50  *      advice, and patience too.
  51  *
  52  */
  53
  54 #include <linux/config.h>
  55 #include <linux/kernel.h>
  56 #include <linux/errno.h>
  57 #include <linux/init.h>
  58 #include <linux/slab.h>
  59 #include <linux/tty.h>
  60 #include <linux/tty_driver.h>
  61 #include <linux/tty_flip.h>
  62 #include <linux/module.h>
  63 #include <linux/spinlock.h>
  64 #include <asm/uaccess.h>
  65 #include <linux/usb.h>
  66 #include "usb-serial.h"
  67
  68 static int debug;
  69
  70 /*
  71  * Version Information
  72  */
  73 #define DRIVER_VERSION "v1.2"
  74 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Gary Brubaker <xavyer@ix.netcom.com>"
  75 #define DRIVER_DESC "USB Empeg Mark I/II Driver"
  76
  77 #define EMPEG_VENDOR_ID                 0x084f
  78 #define EMPEG_PRODUCT_ID                0x0001
  79
  80 /* function prototypes for an empeg-car player */
  81 static int  empeg_open                  (struct usb_serial_port *port, struct file *filp);
  82 static void empeg_close                 (struct usb_serial_port *port, struct file *filp);
  83 static int  empeg_write                 (struct usb_serial_port *port,
  84                                         const unsigned char *buf,
  85                                         int count);
  86 static int  empeg_write_room            (struct usb_serial_port *port);
  87 static int  empeg_chars_in_buffer       (struct usb_serial_port *port);
  88 static void empeg_throttle              (struct usb_serial_port *port);
  89 static void empeg_unthrottle            (struct usb_serial_port *port);
  90 static int  empeg_startup               (struct usb_serial *serial);
  91 static void empeg_shutdown              (struct usb_serial *serial);
  92 static int  empeg_ioctl                 (struct usb_serial_port *port,
  93                                         struct file * file,
  94                                         unsigned int cmd,
  95                                         unsigned long arg);
  96 static void empeg_set_termios           (struct usb_serial_port *port, struct termios *old_termios);
  97 static void empeg_write_bulk_callback   (struct urb *urb, struct pt_regs *regs);
  98 static void empeg_read_bulk_callback    (struct urb *urb, struct pt_regs *regs);
  99
 100 static struct usb_device_id id_table [] = {
 101         { USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
 102         { }                                     /* Terminating entry */
 103 };
 104
 105 MODULE_DEVICE_TABLE (usb, id_table);
 106
 107 static struct usb_driver empeg_driver = {
 108         .owner =        THIS_MODULE,
 109         .name =         "empeg",
 110         .probe =        usb_serial_probe,
 111         .disconnect =   usb_serial_disconnect,
 112         .id_table =     id_table,
 113 };
 114
 115 static struct usb_serial_driver empeg_device = {
 116         .driver = {
 117                 .owner =        THIS_MODULE,
 118                 .name =         "empeg",
 119         },
 120         .id_table =             id_table,
 121         .num_interrupt_in =     0,
 122         .num_bulk_in =          1,
 123         .num_bulk_out =         1,
 124         .num_ports =            1,
 125         .open =                 empeg_open,
 126         .close =                empeg_close,
 127         .throttle =             empeg_throttle,
 128         .unthrottle =           empeg_unthrottle,
 129         .attach =               empeg_startup,
 130         .shutdown =             empeg_shutdown,
 131         .ioctl =                empeg_ioctl,
 132         .set_termios =          empeg_set_termios,
 133         .write =                empeg_write,
 134         .write_room =           empeg_write_room,
 135         .chars_in_buffer =      empeg_chars_in_buffer,
 136         .write_bulk_callback =  empeg_write_bulk_callback,
 137         .read_bulk_callback =   empeg_read_bulk_callback,
 138 };
 139
 140 #define NUM_URBS                        16
 141 #define URB_TRANSFER_BUFFER_SIZE        4096
 142
 143 static struct urb       *write_urb_pool[NUM_URBS];
 144 static spinlock_t       write_urb_pool_lock;
 145 static int              bytes_in;
 146 static int              bytes_out;
 147
 148 /******************************************************************************
 149  * Empeg specific driver functions
 150  ******************************************************************************/
 151 static int empeg_open (struct usb_serial_port *port, struct file *filp)
 152 {
 153         struct usb_serial *serial = port->serial;
 154         int result = 0;
 155
 156         dbg("%s - port %d", __FUNCTION__, port->number);
 157
 158         /* Force default termio settings */
 159         empeg_set_termios (port, NULL) ;
 160
 161         bytes_in = 0;
 162         bytes_out = 0;
 163
 164         /* Start reading from the device */
 165         usb_fill_bulk_urb(
 166                 port->read_urb,
 167                 serial->dev,
 168                 usb_rcvbulkpipe(serial->dev,
 169                         port->bulk_in_endpointAddress),
 170                 port->read_urb->transfer_buffer,
 171                 port->read_urb->transfer_buffer_length,
 172                 empeg_read_bulk_callback,
 173                 port);
 174
 175         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 176
 177         if (result)
 178                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
 179
 180         return result;
 181 }
 182
 183
 184 static void empeg_close (struct usb_serial_port *port, struct file * filp)
 185 {
 186         dbg("%s - port %d", __FUNCTION__, port->number);
 187
 188         /* shutdown our bulk read */
 189         usb_kill_urb(port->read_urb);
 190         /* Uncomment the following line if you want to see some statistics in your syslog */
 191         /* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
 192 }
 193
 194
 195 static int empeg_write (struct usb_serial_port *port, const unsigned char *buf, int count)
 196 {
 197         struct usb_serial *serial = port->serial;
 198         struct urb *urb;
 199         const unsigned char *current_position = buf;
 200         unsigned long flags;
 201         int status;
 202         int i;
 203         int bytes_sent = 0;
 204         int transfer_size;
 205
 206         dbg("%s - port %d", __FUNCTION__, port->number);
 207
 208         while (count > 0) {
 209
 210                 /* try to find a free urb in our list of them */
 211                 urb = NULL;
 212
 213                 spin_lock_irqsave (&write_urb_pool_lock, flags);
 214
 215                 for (i = 0; i < NUM_URBS; ++i) {
 216                         if (write_urb_pool[i]->status != -EINPROGRESS) {
 217                                 urb = write_urb_pool[i];
 218                                 break;
 219                         }
 220                 }
 221
 222                 spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 223
 224                 if (urb == NULL) {
 225                         dbg("%s - no more free urbs", __FUNCTION__);
 226                         goto exit;
 227                 }
 228
 229                 if (urb->transfer_buffer == NULL) {
 230                         urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
 231                         if (urb->transfer_buffer == NULL) {
 232                                 dev_err(&port->dev, "%s no more kernel memory...\n", __FUNCTION__);
 233                                 goto exit;
 234                         }
 235                 }
 236
 237                 transfer_size = min (count, URB_TRANSFER_BUFFER_SIZE);
 238
 239                 memcpy (urb->transfer_buffer, current_position, transfer_size);
 240
 241                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size, urb->transfer_buffer);
 242
 243                 /* build up our urb */
 244                 usb_fill_bulk_urb (
 245                         urb,
 246                         serial->dev,
 247                         usb_sndbulkpipe(serial->dev,
 248                                 port->bulk_out_endpointAddress),
 249                         urb->transfer_buffer,
 250                         transfer_size,
 251                         empeg_write_bulk_callback,
 252                         port);
 253
 254                 /* send it down the pipe */
 255                 status = usb_submit_urb(urb, GFP_ATOMIC);
 256                 if (status) {
 257                         dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __FUNCTION__, status);
 258                         bytes_sent = status;
 259                         break;
 260                 }
 261
 262                 current_position += transfer_size;
 263                 bytes_sent += transfer_size;
 264                 count -= transfer_size;
 265                 bytes_out += transfer_size;
 266
 267         }
 268
 269 exit:
 270         return bytes_sent;
 271
 272 }
 273
 274
 275 static int empeg_write_room (struct usb_serial_port *port)
 276 {
 277         unsigned long flags;
 278         int i;
 279         int room = 0;
 280
 281         dbg("%s - port %d", __FUNCTION__, port->number);
 282
 283         spin_lock_irqsave (&write_urb_pool_lock, flags);
 284
 285         /* tally up the number of bytes available */
 286         for (i = 0; i < NUM_URBS; ++i) {
 287                 if (write_urb_pool[i]->status != -EINPROGRESS) {
 288                         room += URB_TRANSFER_BUFFER_SIZE;
 289                 }
 290         }
 291
 292         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 293
 294         dbg("%s - returns %d", __FUNCTION__, room);
 295
 296         return (room);
 297
 298 }
 299
 300
 301 static int empeg_chars_in_buffer (struct usb_serial_port *port)
 302 {
 303         unsigned long flags;
 304         int i;
 305         int chars = 0;
 306
 307         dbg("%s - port %d", __FUNCTION__, port->number);
 308
 309         spin_lock_irqsave (&write_urb_pool_lock, flags);
 310
 311         /* tally up the number of bytes waiting */
 312         for (i = 0; i < NUM_URBS; ++i) {
 313                 if (write_urb_pool[i]->status == -EINPROGRESS) {
 314                         chars += URB_TRANSFER_BUFFER_SIZE;
 315                 }
 316         }
 317
 318         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 319
 320         dbg("%s - returns %d", __FUNCTION__, chars);
 321
 322         return (chars);
 323
 324 }
 325
 326
 327 static void empeg_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
 328 {
 329         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 330
 331         dbg("%s - port %d", __FUNCTION__, port->number);
 332
 333         if (urb->status) {
 334                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 335                 return;
 336         }
 337
 338         schedule_work(&port->work);
 339 }
 340
 341
 342 static void empeg_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
 343 {
 344         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 345         struct tty_struct *tty;
 346         unsigned char *data = urb->transfer_buffer;
 347         int i;
 348         int result;
 349
 350         dbg("%s - port %d", __FUNCTION__, port->number);
 351
 352         if (urb->status) {
 353                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
 354                 return;
 355         }
 356
 357         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 358
 359         tty = port->tty;
 360
 361         if (urb->actual_length) {
 362                 for (i = 0; i < urb->actual_length ; ++i) {
 363                         /* gb - 2000/11/13
 364                          * If we insert too many characters we'll overflow the buffer.
 365                          * This means we'll lose bytes - Decidedly bad.
 366                          */
 367                         if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
 368                                 tty_flip_buffer_push(tty);
 369                                 }
 370                         tty_insert_flip_char(tty, data[i], 0);
 371                 }
 372                 /* gb - 2000/11/13
 373                  * Goes straight through instead of scheduling - if tty->low_latency is set.
 374                  */
 375                 tty_flip_buffer_push(tty);
 376                 bytes_in += urb->actual_length;
 377         }
 378
 379         /* Continue trying to always read  */
 380         usb_fill_bulk_urb(
 381                 port->read_urb,
 382                 port->serial->dev,
 383                 usb_rcvbulkpipe(port->serial->dev,
 384                         port->bulk_in_endpointAddress),
 385                 port->read_urb->transfer_buffer,
 386                 port->read_urb->transfer_buffer_length,
 387                 empeg_read_bulk_callback,
 388                 port);
 389
 390         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 391
 392         if (result)
 393                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 394
 395         return;
 396
 397 }
 398
 399
 400 static void empeg_throttle (struct usb_serial_port *port)
 401 {
 402         dbg("%s - port %d", __FUNCTION__, port->number);
 403         usb_kill_urb(port->read_urb);
 404 }
 405
 406
 407 static void empeg_unthrottle (struct usb_serial_port *port)
 408 {
 409         int result;
 410
 411         dbg("%s - port %d", __FUNCTION__, port->number);
 412
 413         port->read_urb->dev = port->serial->dev;
 414
 415         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 416
 417         if (result)
 418                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
 419
 420         return;
 421 }
 422
 423
 424 static int  empeg_startup (struct usb_serial *serial)
 425 {
 426         int r;
 427
 428         dbg("%s", __FUNCTION__);
 429
 430         if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
 431                 err("active config #%d != 1 ??",
 432                         serial->dev->actconfig->desc.bConfigurationValue);
 433                 return -ENODEV;
 434         }
 435         dbg("%s - reset config", __FUNCTION__);
 436         r = usb_reset_configuration (serial->dev);
 437
 438         /* continue on with initialization */
 439         return r;
 440
 441 }
 442
 443
 444 static void empeg_shutdown (struct usb_serial *serial)
 445 {
 446         dbg ("%s", __FUNCTION__);
 447 }
 448
 449
 450 static int empeg_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
 451 {
 452         dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
 453
 454         return -ENOIOCTLCMD;
 455 }
 456
 457
 458 static void empeg_set_termios (struct usb_serial_port *port, struct termios *old_termios)
 459 {
 460
 461         dbg("%s - port %d", __FUNCTION__, port->number);
 462
 463         if ((!port->tty) || (!port->tty->termios)) {
 464                 dbg("%s - no tty structures", __FUNCTION__);
 465                 return;
 466         }
 467
 468         /*
 469          * The empeg-car player wants these particular tty settings.
 470          * You could, for example, change the baud rate, however the
 471          * player only supports 115200 (currently), so there is really
 472          * no point in support for changes to the tty settings.
 473          * (at least for now)
 474          *
 475          * The default requirements for this device are:
 476          */
 477         port->tty->termios->c_iflag
 478                 &= ~(IGNBRK     /* disable ignore break */
 479                 | BRKINT        /* disable break causes interrupt */
 480                 | PARMRK        /* disable mark parity errors */
 481                 | ISTRIP        /* disable clear high bit of input characters */
 482                 | INLCR         /* disable translate NL to CR */
 483                 | IGNCR         /* disable ignore CR */
 484                 | ICRNL         /* disable translate CR to NL */
 485                 | IXON);        /* disable enable XON/XOFF flow control */
 486
 487         port->tty->termios->c_oflag
 488                 &= ~OPOST;      /* disable postprocess output characters */
 489
 490         port->tty->termios->c_lflag
 491                 &= ~(ECHO       /* disable echo input characters */
 492                 | ECHONL        /* disable echo new line */
 493                 | ICANON        /* disable erase, kill, werase, and rprnt special characters */
 494                 | ISIG          /* disable interrupt, quit, and suspend special characters */
 495                 | IEXTEN);      /* disable non-POSIX special characters */
 496
 497         port->tty->termios->c_cflag
 498                 &= ~(CSIZE      /* no size */
 499                 | PARENB        /* disable parity bit */
 500                 | CBAUD);       /* clear current baud rate */
 501
 502         port->tty->termios->c_cflag
 503                 |= (CS8         /* character size 8 bits */
 504                 | B115200);     /* baud rate 115200 */
 505
 506         /*
 507          * Force low_latency on; otherwise the pushes are scheduled;
 508          * this is bad as it opens up the possibility of dropping bytes
 509          * on the floor.  We don't want to drop bytes on the floor. :)
 510          */
 511         port->tty->low_latency = 1;
 512
 513         return;
 514 }
 515
 516
 517 static int __init empeg_init (void)
 518 {
 519         struct urb *urb;
 520         int i, retval;
 521
 522         /* create our write urb pool and transfer buffers */
 523         spin_lock_init (&write_urb_pool_lock);
 524         for (i = 0; i < NUM_URBS; ++i) {
 525                 urb = usb_alloc_urb(0, GFP_KERNEL);
 526                 write_urb_pool[i] = urb;
 527                 if (urb == NULL) {
 528                         err("No more urbs???");
 529                         continue;
 530                 }
 531
 532                 urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
 533                 if (!urb->transfer_buffer) {
 534                         err("%s - out of memory for urb buffers.",
 535                             __FUNCTION__);
 536                         continue;
 537                 }
 538         }
 539
 540         retval = usb_serial_register(&empeg_device);
 541         if (retval)
 542                 goto failed_usb_serial_register;
 543         retval = usb_register(&empeg_driver);
 544         if (retval)
 545                 goto failed_usb_register;
 546
 547         info(DRIVER_VERSION ":" DRIVER_DESC);
 548
 549         return 0;
 550 failed_usb_register:
 551         usb_serial_deregister(&empeg_device);
 552 failed_usb_serial_register:
 553         for (i = 0; i < NUM_URBS; ++i) {
 554                 if (write_urb_pool[i]) {
 555                         kfree(write_urb_pool[i]->transfer_buffer);
 556                         usb_free_urb(write_urb_pool[i]);
 557                 }
 558         }
 559         return retval;
 560 }
 561
 562
 563 static void __exit empeg_exit (void)
 564 {
 565         int i;
 566         unsigned long flags;
 567
 568         usb_deregister(&empeg_driver);
 569         usb_serial_deregister (&empeg_device);
 570
 571         spin_lock_irqsave (&write_urb_pool_lock, flags);
 572
 573         for (i = 0; i < NUM_URBS; ++i) {
 574                 if (write_urb_pool[i]) {
 575                         /* FIXME - uncomment the following usb_kill_urb call when
 576                          * the host controllers get fixed to set urb->dev = NULL after
 577                          * the urb is finished.  Otherwise this call oopses. */
 578                         /* usb_kill_urb(write_urb_pool[i]); */
 579                         kfree(write_urb_pool[i]->transfer_buffer);
 580                         usb_free_urb (write_urb_pool[i]);
 581                 }
 582         }
 583
 584         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 585 }
 586
 587
 588 module_init(empeg_init);
 589 module_exit(empeg_exit);
 590
 591 MODULE_AUTHOR( DRIVER_AUTHOR );
 592 MODULE_DESCRIPTION( DRIVER_DESC );
 593 MODULE_LICENSE("GPL");
 594
 595 module_param(debug, bool, S_IRUGO | S_IWUSR);
 596 MODULE_PARM_DESC(debug, "Debug enabled or not");