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