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