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 static void empeg_close(struct usb_serial_port *port);
  84 static int  empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
  85                                                 const unsigned char *buf,
  86                                                 int count);
  87 static int  empeg_write_room(struct tty_struct *tty);
  88 static int  empeg_chars_in_buffer(struct tty_struct *tty);
  89 static void empeg_throttle(struct tty_struct *tty);
  90 static void empeg_unthrottle(struct tty_struct *tty);
  91 static int  empeg_startup(struct usb_serial *serial);
  92 static void empeg_init_termios(struct tty_struct *tty);
  93 static void empeg_write_bulk_callback(struct urb *urb);
  94 static void empeg_read_bulk_callback(struct urb *urb);
  95
  96 static struct usb_device_id id_table [] = {
  97         { USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
  98         { }                                     /* Terminating entry */
  99 };
 100
 101 MODULE_DEVICE_TABLE(usb, id_table);
 102
 103 static struct usb_driver empeg_driver = {
 104         .name =         "empeg",
 105         .probe =        usb_serial_probe,
 106         .disconnect =   usb_serial_disconnect,
 107         .id_table =     id_table,
 108         .no_dynamic_id =        1,
 109 };
 110
 111 static struct usb_serial_driver empeg_device = {
 112         .driver = {
 113                 .owner =        THIS_MODULE,
 114                 .name =         "empeg",
 115         },
 116         .id_table =             id_table,
 117         .usb_driver =           &empeg_driver,
 118         .num_ports =            1,
 119         .open =                 empeg_open,
 120         .close =                empeg_close,
 121         .throttle =             empeg_throttle,
 122         .unthrottle =           empeg_unthrottle,
 123         .attach =               empeg_startup,
 124         .init_termios =         empeg_init_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 {
 145         struct usb_serial *serial = port->serial;
 146         int result = 0;
 147
 148         dbg("%s - port %d", __func__, port->number);
 149
 150         bytes_in = 0;
 151         bytes_out = 0;
 152
 153         /* Start reading from the device */
 154         usb_fill_bulk_urb(
 155                 port->read_urb,
 156                 serial->dev,
 157                 usb_rcvbulkpipe(serial->dev,
 158                         port->bulk_in_endpointAddress),
 159                 port->read_urb->transfer_buffer,
 160                 port->read_urb->transfer_buffer_length,
 161                 empeg_read_bulk_callback,
 162                 port);
 163
 164         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 165
 166         if (result)
 167                 dev_err(&port->dev,
 168                         "%s - failed submitting read urb, error %d\n",
 169                                                         __func__, result);
 170
 171         return result;
 172 }
 173
 174
 175 static void empeg_close(struct usb_serial_port *port)
 176 {
 177         dbg("%s - port %d", __func__, port->number);
 178
 179         /* shutdown our bulk read */
 180         usb_kill_urb(port->read_urb);
 181         /* Uncomment the following line if you want to see some statistics in your syslog */
 182         /* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
 183 }
 184
 185
 186 static int empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
 187                                         const unsigned char *buf, int count)
 188 {
 189         struct usb_serial *serial = port->serial;
 190         struct urb *urb;
 191         const unsigned char *current_position = buf;
 192         unsigned long flags;
 193         int status;
 194         int i;
 195         int bytes_sent = 0;
 196         int transfer_size;
 197
 198         dbg("%s - port %d", __func__, port->number);
 199
 200         while (count > 0) {
 201                 /* try to find a free urb in our list of them */
 202                 urb = NULL;
 203
 204                 spin_lock_irqsave(&write_urb_pool_lock, flags);
 205
 206                 for (i = 0; i < NUM_URBS; ++i) {
 207                         if (write_urb_pool[i]->status != -EINPROGRESS) {
 208                                 urb = write_urb_pool[i];
 209                                 break;
 210                         }
 211                 }
 212
 213                 spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 214
 215                 if (urb == NULL) {
 216                         dbg("%s - no more free urbs", __func__);
 217                         goto exit;
 218                 }
 219
 220                 if (urb->transfer_buffer == NULL) {
 221                         urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
 222                         if (urb->transfer_buffer == NULL) {
 223                                 dev_err(&port->dev,
 224                                         "%s no more kernel memory...\n",
 225                                                                 __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         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 282         dbg("%s - returns %d", __func__, room);
 283         return room;
 284
 285 }
 286
 287
 288 static int empeg_chars_in_buffer(struct tty_struct *tty)
 289 {
 290         struct usb_serial_port *port = tty->driver_data;
 291         unsigned long flags;
 292         int i;
 293         int chars = 0;
 294
 295         dbg("%s - port %d", __func__, port->number);
 296
 297         spin_lock_irqsave(&write_urb_pool_lock, flags);
 298
 299         /* tally up the number of bytes waiting */
 300         for (i = 0; i < NUM_URBS; ++i) {
 301                 if (write_urb_pool[i]->status == -EINPROGRESS)
 302                         chars += URB_TRANSFER_BUFFER_SIZE;
 303         }
 304
 305         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 306         dbg("%s - returns %d", __func__, chars);
 307         return chars;
 308 }
 309
 310
 311 static void empeg_write_bulk_callback(struct urb *urb)
 312 {
 313         struct usb_serial_port *port = urb->context;
 314         int status = urb->status;
 315
 316         dbg("%s - port %d", __func__, port->number);
 317
 318         if (status) {
 319                 dbg("%s - nonzero write bulk status received: %d",
 320                     __func__, status);
 321                 return;
 322         }
 323
 324         usb_serial_port_softint(port);
 325 }
 326
 327
 328 static void empeg_read_bulk_callback(struct urb *urb)
 329 {
 330         struct usb_serial_port *port = urb->context;
 331         struct tty_struct *tty;
 332         unsigned char *data = urb->transfer_buffer;
 333         int result;
 334         int status = urb->status;
 335
 336         dbg("%s - port %d", __func__, port->number);
 337
 338         if (status) {
 339                 dbg("%s - nonzero read bulk status received: %d",
 340                     __func__, status);
 341                 return;
 342         }
 343
 344         usb_serial_debug_data(debug, &port->dev, __func__,
 345                                                 urb->actual_length, data);
 346         tty = tty_port_tty_get(&port->port);
 347
 348         if (urb->actual_length) {
 349                 tty_buffer_request_room(tty, urb->actual_length);
 350                 tty_insert_flip_string(tty, data, urb->actual_length);
 351                 tty_flip_buffer_push(tty);
 352                 bytes_in += urb->actual_length;
 353         }
 354         tty_kref_put(tty);
 355
 356         /* Continue trying to always read  */
 357         usb_fill_bulk_urb(
 358                 port->read_urb,
 359                 port->serial->dev,
 360                 usb_rcvbulkpipe(port->serial->dev,
 361                         port->bulk_in_endpointAddress),
 362                 port->read_urb->transfer_buffer,
 363                 port->read_urb->transfer_buffer_length,
 364                 empeg_read_bulk_callback,
 365                 port);
 366
 367         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 368
 369         if (result)
 370                 dev_err(&urb->dev->dev,
 371                         "%s - failed resubmitting read urb, error %d\n",
 372                                                         __func__, result);
 373
 374         return;
 375
 376 }
 377
 378
 379 static void empeg_throttle(struct tty_struct *tty)
 380 {
 381         struct usb_serial_port *port = tty->driver_data;
 382         dbg("%s - port %d", __func__, port->number);
 383         usb_kill_urb(port->read_urb);
 384 }
 385
 386
 387 static void empeg_unthrottle(struct tty_struct *tty)
 388 {
 389         struct usb_serial_port *port = tty->driver_data;
 390         int result;
 391         dbg("%s - port %d", __func__, port->number);
 392
 393         port->read_urb->dev = port->serial->dev;
 394         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 395         if (result)
 396                 dev_err(&port->dev,
 397                         "%s - failed submitting read urb, error %d\n",
 398                                                         __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                 dev_err(&serial->dev->dev, "active config #%d != 1 ??\n",
 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_init_termios(struct tty_struct *tty)
 423 {
 424         struct ktermios *termios = tty->termios;
 425
 426         /*
 427          * The empeg-car player wants these particular tty settings.
 428          * You could, for example, change the baud rate, however the
 429          * player only supports 115200 (currently), so there is really
 430          * no point in support for changes to the tty settings.
 431          * (at least for now)
 432          *
 433          * The default requirements for this device are:
 434          */
 435         termios->c_iflag
 436                 &= ~(IGNBRK     /* disable ignore break */
 437                 | BRKINT        /* disable break causes interrupt */
 438                 | PARMRK        /* disable mark parity errors */
 439                 | ISTRIP        /* disable clear high bit of input characters */
 440                 | INLCR         /* disable translate NL to CR */
 441                 | IGNCR         /* disable ignore CR */
 442                 | ICRNL         /* disable translate CR to NL */
 443                 | IXON);        /* disable enable XON/XOFF flow control */
 444
 445         termios->c_oflag
 446                 &= ~OPOST;      /* disable postprocess output characters */
 447
 448         termios->c_lflag
 449                 &= ~(ECHO       /* disable echo input characters */
 450                 | ECHONL        /* disable echo new line */
 451                 | ICANON        /* disable erase, kill, werase, and rprnt special characters */
 452                 | ISIG          /* disable interrupt, quit, and suspend special characters */
 453                 | IEXTEN);      /* disable non-POSIX special characters */
 454
 455         termios->c_cflag
 456                 &= ~(CSIZE      /* no size */
 457                 | PARENB        /* disable parity bit */
 458                 | CBAUD);       /* clear current baud rate */
 459
 460         termios->c_cflag
 461                 |= CS8;         /* character size 8 bits */
 462
 463         tty_encode_baud_rate(tty, 115200, 115200);
 464 }
 465
 466
 467 static int __init empeg_init(void)
 468 {
 469         struct urb *urb;
 470         int i, retval;
 471
 472         /* create our write urb pool and transfer buffers */
 473         spin_lock_init(&write_urb_pool_lock);
 474         for (i = 0; i < NUM_URBS; ++i) {
 475                 urb = usb_alloc_urb(0, GFP_KERNEL);
 476                 write_urb_pool[i] = urb;
 477                 if (urb == NULL) {
 478                         printk(KERN_ERR "empeg: No more urbs???\n");
 479                         continue;
 480                 }
 481
 482                 urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
 483                                                                 GFP_KERNEL);
 484                 if (!urb->transfer_buffer) {
 485                         printk(KERN_ERR "empeg: %s - out of memory for urb "
 486                                "buffers.", __func__);
 487                         continue;
 488                 }
 489         }
 490
 491         retval = usb_serial_register(&empeg_device);
 492         if (retval)
 493                 goto failed_usb_serial_register;
 494         retval = usb_register(&empeg_driver);
 495         if (retval)
 496                 goto failed_usb_register;
 497
 498         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
 499                DRIVER_DESC "\n");
 500
 501         return 0;
 502 failed_usb_register:
 503         usb_serial_deregister(&empeg_device);
 504 failed_usb_serial_register:
 505         for (i = 0; i < NUM_URBS; ++i) {
 506                 if (write_urb_pool[i]) {
 507                         kfree(write_urb_pool[i]->transfer_buffer);
 508                         usb_free_urb(write_urb_pool[i]);
 509                 }
 510         }
 511         return retval;
 512 }
 513
 514
 515 static void __exit empeg_exit(void)
 516 {
 517         int i;
 518         unsigned long flags;
 519
 520         usb_deregister(&empeg_driver);
 521         usb_serial_deregister(&empeg_device);
 522
 523         spin_lock_irqsave(&write_urb_pool_lock, flags);
 524
 525         for (i = 0; i < NUM_URBS; ++i) {
 526                 if (write_urb_pool[i]) {
 527                         /* FIXME - uncomment the following usb_kill_urb call
 528                          * when the host controllers get fixed to set urb->dev
 529                          * = NULL after the urb is finished.  Otherwise this
 530                          * call oopses. */
 531                         /* usb_kill_urb(write_urb_pool[i]); */
 532                         kfree(write_urb_pool[i]->transfer_buffer);
 533                         usb_free_urb(write_urb_pool[i]);
 534                 }
 535         }
 536         spin_unlock_irqrestore(&write_urb_pool_lock, flags);
 537 }
 538
 539
 540 module_init(empeg_init);
 541 module_exit(empeg_exit);
 542
 543 MODULE_AUTHOR(DRIVER_AUTHOR);
 544 MODULE_DESCRIPTION(DRIVER_DESC);
 545 MODULE_LICENSE("GPL");
 546
 547 module_param(debug, bool, S_IRUGO | S_IWUSR);
 548 MODULE_PARM_DESC(debug, "Debug enabled or not");