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