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 tty->ldisc.set_termios(port, tty, NULL) to empeg_open().
  37  *      This notifies the tty driver that the termios have changed.
  38  *
  39  * (11/13/2000) gb
  40  *      Moved tty->low_latency = 1 from empeg_read_bulk_callback() to
  41  *      empeg_open() (It only needs to be set once - Doh!)
  42  *
  43  * (11/11/2000) gb
  44  *      Updated to work with id_table structure.
  45  *
  46  * (11/04/2000) gb
  47  *      Forked this from visor.c, and hacked it up to work with an
  48  *      Empeg ltd. empeg-car player.  Constructive criticism welcomed.
  49  *      I would like to say, 'Thank You' to Greg Kroah-Hartman for the
  50  *      use of his code, and for his guidance, advice and patience. :)
  51  *      A 'Thank You' is in order for John Ripley of Empeg ltd for his
  52  *      advice, and patience too.
  53  *
  54  */
  55
  56 #include <linux/kernel.h>
  57 #include <linux/errno.h>
  58 #include <linux/init.h>
  59 #include <linux/slab.h>
  60 #include <linux/tty.h>
  61 #include <linux/tty_driver.h>
  62 #include <linux/tty_flip.h>
  63 #include <linux/module.h>
  64 #include <linux/spinlock.h>
  65 #include <linux/uaccess.h>
  66 #include <linux/usb.h>
  67 #include <linux/usb/serial.h>
  68
  69 static int debug;
  70
  71 /*
  72  * Version Information
  73  */
  74 #define DRIVER_VERSION "v1.2"
  75 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Gary Brubaker <xavyer@ix.netcom.com>"
  76 #define DRIVER_DESC "USB Empeg Mark I/II Driver"
  77
  78 #define EMPEG_VENDOR_ID                 0x084f
  79 #define EMPEG_PRODUCT_ID                0x0001
  80
  81 /* function prototypes for an empeg-car player */
  82 static int  empeg_open(struct tty_struct *tty, struct usb_serial_port *port,
  83                                                 struct file *filp);
  84 static void empeg_close(struct tty_struct *tty, struct usb_serial_port *port,
  85                                                 struct file *filp);
  86 static int  empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
  87                                                 const unsigned char *buf,
  88                                                 int count);
  89 static int  empeg_write_room(struct tty_struct *tty);
  90 static int  empeg_chars_in_buffer(struct tty_struct *tty);
  91 static void empeg_throttle(struct tty_struct *tty);
  92 static void empeg_unthrottle(struct tty_struct *tty);
  93 static int  empeg_startup(struct usb_serial *serial);
  94 static void empeg_shutdown(struct usb_serial *serial);
  95 static void empeg_set_termios(struct tty_struct *tty,
  96                 struct usb_serial_port *port, struct ktermios *old_termios);
  97 static void empeg_write_bulk_callback(struct urb *urb);
  98 static void empeg_read_bulk_callback(struct urb *urb);
  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         .name =         "empeg",
 109         .probe =        usb_serial_probe,
 110         .disconnect =   usb_serial_disconnect,
 111         .id_table =     id_table,
 112         .no_dynamic_id =        1,
 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         .usb_driver =           &empeg_driver,
 122         .num_ports =            1,
 123         .open =                 empeg_open,
 124         .close =                empeg_close,
 125         .throttle =             empeg_throttle,
 126         .unthrottle =           empeg_unthrottle,
 127         .attach =               empeg_startup,
 128         .shutdown =             empeg_shutdown,
 129         .set_termios =          empeg_set_termios,
 130         .write =                empeg_write,
 131         .write_room =           empeg_write_room,
 132         .chars_in_buffer =      empeg_chars_in_buffer,
 133         .write_bulk_callback =  empeg_write_bulk_callback,
 134         .read_bulk_callback =   empeg_read_bulk_callback,
 135 };
 136
 137 #define NUM_URBS                        16
 138 #define URB_TRANSFER_BUFFER_SIZE        4096
 139
 140 static struct urb       *write_urb_pool[NUM_URBS];
 141 static spinlock_t       write_urb_pool_lock;
 142 static int              bytes_in;
 143 static int              bytes_out;
 144
 145 /******************************************************************************
 146  * Empeg specific driver functions
 147  ******************************************************************************/
 148 static int empeg_open(struct tty_struct *tty, struct usb_serial_port *port,
 149                                 struct file *filp)
 150 {
 151         struct usb_serial *serial = port->serial;
 152         int result = 0;
 153
 154         dbg("%s - port %d", __func__, port->number);
 155
 156         /* Force default termio settings */
 157         empeg_set_termios(tty, port, NULL) ;
 158
 159         bytes_in = 0;
 160         bytes_out = 0;
 161
 162         /* Start reading from the device */
 163         usb_fill_bulk_urb(
 164                 port->read_urb,
 165                 serial->dev,
 166                 usb_rcvbulkpipe(serial->dev,
 167                         port->bulk_in_endpointAddress),
 168                 port->read_urb->transfer_buffer,
 169                 port->read_urb->transfer_buffer_length,
 170                 empeg_read_bulk_callback,
 171                 port);
 172
 173         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 174
 175         if (result)
 176                 dev_err(&port->dev,
 177                         "%s - failed submitting read urb, error %d\n",
 178                                                         __func__, result);
 179
 180         return result;
 181 }
 182
 183
 184 static void empeg_close(struct tty_struct *tty, struct usb_serial_port *port,
 185                                 struct file *filp)
 186 {
 187         dbg("%s - port %d", __func__, port->number);
 188
 189         /* shutdown our bulk read */
 190         usb_kill_urb(port->read_urb);
 191         /* Uncomment the following line if you want to see some statistics in your syslog */
 192         /* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
 193 }
 194
 195
 196 static int empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
 197                                         const unsigned char *buf, int count)
 198 {
 199         struct usb_serial *serial = port->serial;
 200         struct urb *urb;
 201         const unsigned char *current_position = buf;
 202         unsigned long flags;
 203         int status;
 204         int i;
 205         int bytes_sent = 0;
 206         int transfer_size;
 207
 208         dbg("%s - port %d", __func__, port->number);
 209
 210         while (count > 0) {
 211                 /* try to find a free urb in our list of them */
 212                 urb = NULL;
 213
 214                 spin_lock_irqsave(&write_urb_pool_lock, flags);
 215
 216                 for (i = 0; i < NUM_URBS; ++i) {
 217                         if (write_urb_pool[i]->status != -EINPROGRESS) {
 218                                 urb = write_urb_pool[i];
 219                                 break;
 220                         }
 221                 }
 222
 223                 spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 224
 225                 if (urb == NULL) {
 226                         dbg("%s - no more free urbs", __func__);
 227                         goto exit;
 228                 }
 229
 230                 if (urb->transfer_buffer == NULL) {
 231                         urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
 232                         if (urb->transfer_buffer == NULL) {
 233                                 dev_err(&port->dev,
 234                                         "%s no more kernel memory...\n",
 235                                                                 __func__);
 236                                 goto exit;
 237                         }
 238                 }
 239
 240                 transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
 241
 242                 memcpy(urb->transfer_buffer, current_position, transfer_size);
 243
 244                 usb_serial_debug_data(debug, &port->dev, __func__, transfer_size, urb->transfer_buffer);
 245
 246                 /* build up our urb */
 247                 usb_fill_bulk_urb(
 248                         urb,
 249                         serial->dev,
 250                         usb_sndbulkpipe(serial->dev,
 251                                         port->bulk_out_endpointAddress),
 252                         urb->transfer_buffer,
 253                         transfer_size,
 254                         empeg_write_bulk_callback,
 255                         port);
 256
 257                 /* send it down the pipe */
 258                 status = usb_submit_urb(urb, GFP_ATOMIC);
 259                 if (status) {
 260                         dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __func__, status);
 261                         bytes_sent = status;
 262                         break;
 263                 }
 264
 265                 current_position += transfer_size;
 266                 bytes_sent += transfer_size;
 267                 count -= transfer_size;
 268                 bytes_out += transfer_size;
 269
 270         }
 271 exit:
 272         return bytes_sent;
 273 }
 274
 275
 276 static int empeg_write_room(struct tty_struct *tty)
 277 {
 278         struct usb_serial_port *port = tty->driver_data;
 279         unsigned long flags;
 280         int i;
 281         int room = 0;
 282
 283         dbg("%s - port %d", __func__, port->number);
 284
 285         spin_lock_irqsave(&write_urb_pool_lock, flags);
 286         /* tally up the number of bytes available */
 287         for (i = 0; i < NUM_URBS; ++i) {
 288                 if (write_urb_pool[i]->status != -EINPROGRESS)
 289                         room += URB_TRANSFER_BUFFER_SIZE;
 290         }
 291         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 292         dbg("%s - returns %d", __func__, room);
 293         return room;
 294
 295 }
 296
 297
 298 static int empeg_chars_in_buffer(struct tty_struct *tty)
 299 {
 300         struct usb_serial_port *port = tty->driver_data;
 301         unsigned long flags;
 302         int i;
 303         int chars = 0;
 304
 305         dbg("%s - port %d", __func__, port->number);
 306
 307         spin_lock_irqsave(&write_urb_pool_lock, flags);
 308
 309         /* tally up the number of bytes waiting */
 310         for (i = 0; i < NUM_URBS; ++i) {
 311                 if (write_urb_pool[i]->status == -EINPROGRESS)
 312                         chars += URB_TRANSFER_BUFFER_SIZE;
 313         }
 314
 315         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 316         dbg("%s - returns %d", __func__, chars);
 317         return chars;
 318 }
 319
 320
 321 static void empeg_write_bulk_callback(struct urb *urb)
 322 {
 323         struct usb_serial_port *port = urb->context;
 324         int status = urb->status;
 325
 326         dbg("%s - port %d", __func__, port->number);
 327
 328         if (status) {
 329                 dbg("%s - nonzero write bulk status received: %d",
 330                     __func__, status);
 331                 return;
 332         }
 333
 334         usb_serial_port_softint(port);
 335 }
 336
 337
 338 static void empeg_read_bulk_callback(struct urb *urb)
 339 {
 340         struct usb_serial_port *port = urb->context;
 341         struct tty_struct *tty;
 342         unsigned char *data = urb->transfer_buffer;
 343         int result;
 344         int status = urb->status;
 345
 346         dbg("%s - port %d", __func__, port->number);
 347
 348         if (status) {
 349                 dbg("%s - nonzero read bulk status received: %d",
 350                     __func__, status);
 351                 return;
 352         }
 353
 354         usb_serial_debug_data(debug, &port->dev, __func__,
 355                                                 urb->actual_length, data);
 356         tty = tty_port_tty_get(&port->port);
 357
 358         if (urb->actual_length) {
 359                 tty_buffer_request_room(tty, urb->actual_length);
 360                 tty_insert_flip_string(tty, data, urb->actual_length);
 361                 tty_flip_buffer_push(tty);
 362                 bytes_in += urb->actual_length;
 363         }
 364         tty_kref_put(tty);
 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                 dev_err(&serial->dev->dev, "active config #%d != 1 ??\n",
 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         tty_encode_baud_rate(tty, 115200, 115200);
 482 }
 483
 484
 485 static int __init empeg_init(void)
 486 {
 487         struct urb *urb;
 488         int i, retval;
 489
 490         /* create our write urb pool and transfer buffers */
 491         spin_lock_init(&write_urb_pool_lock);
 492         for (i = 0; i < NUM_URBS; ++i) {
 493                 urb = usb_alloc_urb(0, GFP_KERNEL);
 494                 write_urb_pool[i] = urb;
 495                 if (urb == NULL) {
 496                         printk(KERN_ERR "empeg: No more urbs???\n");
 497                         continue;
 498                 }
 499
 500                 urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
 501                                                                 GFP_KERNEL);
 502                 if (!urb->transfer_buffer) {
 503                         printk(KERN_ERR "empeg: %s - out of memory for urb "
 504                                "buffers.", __func__);
 505                         continue;
 506                 }
 507         }
 508
 509         retval = usb_serial_register(&empeg_device);
 510         if (retval)
 511                 goto failed_usb_serial_register;
 512         retval = usb_register(&empeg_driver);
 513         if (retval)
 514                 goto failed_usb_register;
 515
 516         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
 517                DRIVER_DESC "\n");
 518
 519         return 0;
 520 failed_usb_register:
 521         usb_serial_deregister(&empeg_device);
 522 failed_usb_serial_register:
 523         for (i = 0; i < NUM_URBS; ++i) {
 524                 if (write_urb_pool[i]) {
 525                         kfree(write_urb_pool[i]->transfer_buffer);
 526                         usb_free_urb(write_urb_pool[i]);
 527                 }
 528         }
 529         return retval;
 530 }
 531
 532
 533 static void __exit empeg_exit(void)
 534 {
 535         int i;
 536         unsigned long flags;
 537
 538         usb_deregister(&empeg_driver);
 539         usb_serial_deregister(&empeg_device);
 540
 541         spin_lock_irqsave(&write_urb_pool_lock, flags);
 542
 543         for (i = 0; i < NUM_URBS; ++i) {
 544                 if (write_urb_pool[i]) {
 545                         /* FIXME - uncomment the following usb_kill_urb call
 546                          * when the host controllers get fixed to set urb->dev
 547                          * = NULL after the urb is finished.  Otherwise this
 548                          * call oopses. */
 549                         /* usb_kill_urb(write_urb_pool[i]); */
 550                         kfree(write_urb_pool[i]->transfer_buffer);
 551                         usb_free_urb(write_urb_pool[i]);
 552                 }
 553         }
 554         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 555 }
 556
 557
 558 module_init(empeg_init);
 559 module_exit(empeg_exit);
 560
 561 MODULE_AUTHOR(DRIVER_AUTHOR);
 562 MODULE_DESCRIPTION(DRIVER_DESC);
 563 MODULE_LICENSE("GPL");
 564
 565 module_param(debug, bool, S_IRUGO | S_IWUSR);
 566 MODULE_PARM_DESC(debug, "Debug enabled or not");