drivers/usb/serial/empeg.c

   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                                         int from_user,
  85                                         const unsigned char *buf,
  86                                         int count);
  87 static int  empeg_write_room            (struct usb_serial_port *port);
  88 static int  empeg_chars_in_buffer       (struct usb_serial_port *port);
  89 static void empeg_throttle              (struct usb_serial_port *port);
  90 static void empeg_unthrottle            (struct usb_serial_port *port);
  91 static int  empeg_startup               (struct usb_serial *serial);
  92 static void empeg_shutdown              (struct usb_serial *serial);
  93 static int  empeg_ioctl                 (struct usb_serial_port *port,
  94                                         struct file * file,
  95                                         unsigned int cmd,
  96                                         unsigned long arg);
  97 static void empeg_set_termios           (struct usb_serial_port *port, struct termios *old_termios);
  98 static void empeg_write_bulk_callback   (struct urb *urb, struct pt_regs *regs);
  99 static void empeg_read_bulk_callback    (struct urb *urb, struct pt_regs *regs);
 100
 101 static struct usb_device_id id_table [] = {
 102         { USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
 103         { }                                     /* Terminating entry */
 104 };
 105
 106 MODULE_DEVICE_TABLE (usb, id_table);
 107
 108 static struct usb_driver empeg_driver = {
 109         .owner =        THIS_MODULE,
 110         .name =         "empeg",
 111         .probe =        usb_serial_probe,
 112         .disconnect =   usb_serial_disconnect,
 113         .id_table =     id_table,
 114 };
 115
 116 static struct usb_serial_device_type empeg_device = {
 117         .owner =                THIS_MODULE,
 118         .name =                 "Empeg",
 119         .id_table =             id_table,
 120         .num_interrupt_in =     0,
 121         .num_bulk_in =          1,
 122         .num_bulk_out =         1,
 123         .num_ports =            1,
 124         .open =                 empeg_open,
 125         .close =                empeg_close,
 126         .throttle =             empeg_throttle,
 127         .unthrottle =           empeg_unthrottle,
 128         .attach =               empeg_startup,
 129         .shutdown =             empeg_shutdown,
 130         .ioctl =                empeg_ioctl,
 131         .set_termios =          empeg_set_termios,
 132         .write =                empeg_write,
 133         .write_room =           empeg_write_room,
 134         .chars_in_buffer =      empeg_chars_in_buffer,
 135         .write_bulk_callback =  empeg_write_bulk_callback,
 136         .read_bulk_callback =   empeg_read_bulk_callback,
 137 };
 138
 139 #define NUM_URBS                        16
 140 #define URB_TRANSFER_BUFFER_SIZE        4096
 141
 142 static struct urb       *write_urb_pool[NUM_URBS];
 143 static spinlock_t       write_urb_pool_lock;
 144 static int              bytes_in;
 145 static int              bytes_out;
 146
 147 /******************************************************************************
 148  * Empeg specific driver functions
 149  ******************************************************************************/
 150 static int empeg_open (struct usb_serial_port *port, struct file *filp)
 151 {
 152         struct usb_serial *serial = port->serial;
 153         int result = 0;
 154
 155         dbg("%s - port %d", __FUNCTION__, port->number);
 156
 157         /* Force default termio settings */
 158         empeg_set_termios (port, NULL) ;
 159
 160         bytes_in = 0;
 161         bytes_out = 0;
 162
 163         /* Start reading from the device */
 164         usb_fill_bulk_urb(
 165                 port->read_urb,
 166                 serial->dev,
 167                 usb_rcvbulkpipe(serial->dev,
 168                         port->bulk_in_endpointAddress),
 169                 port->read_urb->transfer_buffer,
 170                 port->read_urb->transfer_buffer_length,
 171                 empeg_read_bulk_callback,
 172                 port);
 173
 174         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 175
 176         if (result)
 177                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
 178
 179         return result;
 180 }
 181
 182
 183 static void empeg_close (struct usb_serial_port *port, struct file * filp)
 184 {
 185         dbg("%s - port %d", __FUNCTION__, port->number);
 186
 187         /* shutdown our bulk read */
 188         usb_unlink_urb (port->read_urb);
 189         /* Uncomment the following line if you want to see some statistics in your syslog */
 190         /* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
 191 }
 192
 193
 194 static int empeg_write (struct usb_serial_port *port, int from_user, const unsigned char *buf, int count)
 195 {
 196         struct usb_serial *serial = port->serial;
 197         struct urb *urb;
 198         const unsigned char *current_position = buf;
 199         unsigned long flags;
 200         int status;
 201         int i;
 202         int bytes_sent = 0;
 203         int transfer_size;
 204
 205         dbg("%s - port %d", __FUNCTION__, port->number);
 206
 207         while (count > 0) {
 208
 209                 /* try to find a free urb in our list of them */
 210                 urb = NULL;
 211
 212                 spin_lock_irqsave (&write_urb_pool_lock, flags);
 213
 214                 for (i = 0; i < NUM_URBS; ++i) {
 215                         if (write_urb_pool[i]->status != -EINPROGRESS) {
 216                                 urb = write_urb_pool[i];
 217                                 break;
 218                         }
 219                 }
 220
 221                 spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 222
 223                 if (urb == NULL) {
 224                         dbg("%s - no more free urbs", __FUNCTION__);
 225                         goto exit;
 226                 }
 227
 228                 if (urb->transfer_buffer == NULL) {
 229                         urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
 230                         if (urb->transfer_buffer == NULL) {
 231                                 dev_err(&port->dev, "%s no more kernel memory...\n", __FUNCTION__);
 232                                 goto exit;
 233                         }
 234                 }
 235
 236                 transfer_size = min (count, URB_TRANSFER_BUFFER_SIZE);
 237
 238                 if (from_user) {
 239                         if (copy_from_user (urb->transfer_buffer, current_position, transfer_size)) {
 240                                 bytes_sent = -EFAULT;
 241                                 break;
 242                         }
 243                 } else {
 244                         memcpy (urb->transfer_buffer, current_position, transfer_size);
 245                 }
 246
 247                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size, urb->transfer_buffer);
 248
 249                 /* build up our urb */
 250                 usb_fill_bulk_urb (
 251                         urb,
 252                         serial->dev,
 253                         usb_sndbulkpipe(serial->dev,
 254                                 port->bulk_out_endpointAddress),
 255                         urb->transfer_buffer,
 256                         transfer_size,
 257                         empeg_write_bulk_callback,
 258                         port);
 259
 260                 /* send it down the pipe */
 261                 status = usb_submit_urb(urb, GFP_ATOMIC);
 262                 if (status) {
 263                         dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __FUNCTION__, status);
 264                         bytes_sent = status;
 265                         break;
 266                 }
 267
 268                 current_position += transfer_size;
 269                 bytes_sent += transfer_size;
 270                 count -= transfer_size;
 271                 bytes_out += transfer_size;
 272
 273         }
 274
 275 exit:
 276         return bytes_sent;
 277
 278 }
 279
 280
 281 static int empeg_write_room (struct usb_serial_port *port)
 282 {
 283         unsigned long flags;
 284         int i;
 285         int room = 0;
 286
 287         dbg("%s - port %d", __FUNCTION__, port->number);
 288
 289         spin_lock_irqsave (&write_urb_pool_lock, flags);
 290
 291         /* tally up the number of bytes available */
 292         for (i = 0; i < NUM_URBS; ++i) {
 293                 if (write_urb_pool[i]->status != -EINPROGRESS) {
 294                         room += URB_TRANSFER_BUFFER_SIZE;
 295                 }
 296         }
 297
 298         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 299
 300         dbg("%s - returns %d", __FUNCTION__, room);
 301
 302         return (room);
 303
 304 }
 305
 306
 307 static int empeg_chars_in_buffer (struct usb_serial_port *port)
 308 {
 309         unsigned long flags;
 310         int i;
 311         int chars = 0;
 312
 313         dbg("%s - port %d", __FUNCTION__, port->number);
 314
 315         spin_lock_irqsave (&write_urb_pool_lock, flags);
 316
 317         /* tally up the number of bytes waiting */
 318         for (i = 0; i < NUM_URBS; ++i) {
 319                 if (write_urb_pool[i]->status == -EINPROGRESS) {
 320                         chars += URB_TRANSFER_BUFFER_SIZE;
 321                 }
 322         }
 323
 324         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 325
 326         dbg("%s - returns %d", __FUNCTION__, chars);
 327
 328         return (chars);
 329
 330 }
 331
 332
 333 static void empeg_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
 334 {
 335         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 336
 337         dbg("%s - port %d", __FUNCTION__, port->number);
 338
 339         if (urb->status) {
 340                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 341                 return;
 342         }
 343
 344         schedule_work(&port->work);
 345 }
 346
 347
 348 static void empeg_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
 349 {
 350         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 351         struct tty_struct *tty;
 352         unsigned char *data = urb->transfer_buffer;
 353         int i;
 354         int result;
 355
 356         dbg("%s - port %d", __FUNCTION__, port->number);
 357
 358         if (urb->status) {
 359                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
 360                 return;
 361         }
 362
 363         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 364
 365         tty = port->tty;
 366
 367         if (urb->actual_length) {
 368                 for (i = 0; i < urb->actual_length ; ++i) {
 369                         /* gb - 2000/11/13
 370                          * If we insert too many characters we'll overflow the buffer.
 371                          * This means we'll lose bytes - Decidedly bad.
 372                          */
 373                         if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
 374                                 tty_flip_buffer_push(tty);
 375                                 }
 376                         tty_insert_flip_char(tty, data[i], 0);
 377                 }
 378                 /* gb - 2000/11/13
 379                  * Goes straight through instead of scheduling - if tty->low_latency is set.
 380                  */
 381                 tty_flip_buffer_push(tty);
 382                 bytes_in += urb->actual_length;
 383         }
 384
 385         /* Continue trying to always read  */
 386         usb_fill_bulk_urb(
 387                 port->read_urb,
 388                 port->serial->dev,
 389                 usb_rcvbulkpipe(port->serial->dev,
 390                         port->bulk_in_endpointAddress),
 391                 port->read_urb->transfer_buffer,
 392                 port->read_urb->transfer_buffer_length,
 393                 empeg_read_bulk_callback,
 394                 port);
 395
 396         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 397
 398         if (result)
 399                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 400
 401         return;
 402
 403 }
 404
 405
 406 static void empeg_throttle (struct usb_serial_port *port)
 407 {
 408         dbg("%s - port %d", __FUNCTION__, port->number);
 409         usb_unlink_urb (port->read_urb);
 410 }
 411
 412
 413 static void empeg_unthrottle (struct usb_serial_port *port)
 414 {
 415         int result;
 416
 417         dbg("%s - port %d", __FUNCTION__, port->number);
 418
 419         port->read_urb->dev = port->serial->dev;
 420
 421         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 422
 423         if (result)
 424                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
 425
 426         return;
 427 }
 428
 429
 430 static int  empeg_startup (struct usb_serial *serial)
 431 {
 432         int r;
 433
 434         dbg("%s", __FUNCTION__);
 435
 436         if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
 437                 err("active config #%d != 1 ??",
 438                         serial->dev->actconfig->desc.bConfigurationValue);
 439                 return -ENODEV;
 440         }
 441         dbg("%s - reset config", __FUNCTION__);
 442         r = usb_reset_configuration (serial->dev);
 443
 444         /* continue on with initialization */
 445         return r;
 446
 447 }
 448
 449
 450 static void empeg_shutdown (struct usb_serial *serial)
 451 {
 452         dbg ("%s", __FUNCTION__);
 453 }
 454
 455
 456 static int empeg_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
 457 {
 458         dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
 459
 460         return -ENOIOCTLCMD;
 461 }
 462
 463
 464 static void empeg_set_termios (struct usb_serial_port *port, struct termios *old_termios)
 465 {
 466
 467         dbg("%s - port %d", __FUNCTION__, port->number);
 468
 469         if ((!port->tty) || (!port->tty->termios)) {
 470                 dbg("%s - no tty structures", __FUNCTION__);
 471                 return;
 472         }
 473
 474         /*
 475          * The empeg-car player wants these particular tty settings.
 476          * You could, for example, change the baud rate, however the
 477          * player only supports 115200 (currently), so there is really
 478          * no point in support for changes to the tty settings.
 479          * (at least for now)
 480          *
 481          * The default requirements for this device are:
 482          */
 483         port->tty->termios->c_iflag
 484                 &= ~(IGNBRK     /* disable ignore break */
 485                 | BRKINT        /* disable break causes interrupt */
 486                 | PARMRK        /* disable mark parity errors */
 487                 | ISTRIP        /* disable clear high bit of input characters */
 488                 | INLCR         /* disable translate NL to CR */
 489                 | IGNCR         /* disable ignore CR */
 490                 | ICRNL         /* disable translate CR to NL */
 491                 | IXON);        /* disable enable XON/XOFF flow control */
 492
 493         port->tty->termios->c_oflag
 494                 &= ~OPOST;      /* disable postprocess output characters */
 495
 496         port->tty->termios->c_lflag
 497                 &= ~(ECHO       /* disable echo input characters */
 498                 | ECHONL        /* disable echo new line */
 499                 | ICANON        /* disable erase, kill, werase, and rprnt special characters */
 500                 | ISIG          /* disable interrupt, quit, and suspend special characters */
 501                 | IEXTEN);      /* disable non-POSIX special characters */
 502
 503         port->tty->termios->c_cflag
 504                 &= ~(CSIZE      /* no size */
 505                 | PARENB        /* disable parity bit */
 506                 | CBAUD);       /* clear current baud rate */
 507
 508         port->tty->termios->c_cflag
 509                 |= (CS8         /* character size 8 bits */
 510                 | B115200);     /* baud rate 115200 */
 511
 512         /*
 513          * Force low_latency on; otherwise the pushes are scheduled;
 514          * this is bad as it opens up the possibility of dropping bytes
 515          * on the floor.  We don't want to drop bytes on the floor. :)
 516          */
 517         port->tty->low_latency = 1;
 518
 519         /* Notify the tty driver that the termios have changed. */
 520         port->tty->ldisc.set_termios(port->tty, NULL);
 521
 522         return;
 523
 524 }
 525
 526
 527 static int __init empeg_init (void)
 528 {
 529         struct urb *urb;
 530         int i, retval;
 531
 532         /* create our write urb pool and transfer buffers */
 533         spin_lock_init (&write_urb_pool_lock);
 534         for (i = 0; i < NUM_URBS; ++i) {
 535                 urb = usb_alloc_urb(0, GFP_KERNEL);
 536                 write_urb_pool[i] = urb;
 537                 if (urb == NULL) {
 538                         err("No more urbs???");
 539                         continue;
 540                 }
 541
 542                 urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
 543                 if (!urb->transfer_buffer) {
 544                         err("%s - out of memory for urb buffers.",
 545                             __FUNCTION__);
 546                         continue;
 547                 }
 548         }
 549
 550         retval = usb_serial_register(&empeg_device);
 551         if (retval)
 552                 goto failed_usb_serial_register;
 553         retval = usb_register(&empeg_driver);
 554         if (retval)
 555                 goto failed_usb_register;
 556
 557         info(DRIVER_VERSION ":" DRIVER_DESC);
 558
 559         return 0;
 560 failed_usb_register:
 561         usb_serial_deregister(&empeg_device);
 562 failed_usb_serial_register:
 563         for (i = 0; i < NUM_URBS; ++i) {
 564                 if (write_urb_pool[i]) {
 565                         if (write_urb_pool[i]->transfer_buffer)
 566                                 kfree(write_urb_pool[i]->transfer_buffer);
 567                         usb_free_urb(write_urb_pool[i]);
 568                 }
 569         }
 570         return retval;
 571 }
 572
 573
 574 static void __exit empeg_exit (void)
 575 {
 576         int i;
 577         unsigned long flags;
 578
 579         usb_deregister(&empeg_driver);
 580         usb_serial_deregister (&empeg_device);
 581
 582         spin_lock_irqsave (&write_urb_pool_lock, flags);
 583
 584         for (i = 0; i < NUM_URBS; ++i) {
 585                 if (write_urb_pool[i]) {
 586                         /* FIXME - uncomment the following usb_unlink_urb call when
 587                          * the host controllers get fixed to set urb->dev = NULL after
 588                          * the urb is finished.  Otherwise this call oopses. */
 589                         /* usb_unlink_urb(write_urb_pool[i]); */
 590                         if (write_urb_pool[i]->transfer_buffer)
 591                                 kfree(write_urb_pool[i]->transfer_buffer);
 592                         usb_free_urb (write_urb_pool[i]);
 593                 }
 594         }
 595
 596         spin_unlock_irqrestore (&write_urb_pool_lock, flags);
 597 }
 598
 599
 600 module_init(empeg_init);
 601 module_exit(empeg_exit);
 602
 603 MODULE_AUTHOR( DRIVER_AUTHOR );
 604 MODULE_DESCRIPTION( DRIVER_DESC );
 605 MODULE_LICENSE("GPL");
 606
 607 module_param(debug, bool, S_IRUGO | S_IWUSR);
 608 MODULE_PARM_DESC(debug, "Debug enabled or not");