drivers/usb/serial/generic.c

   1 /*
   2  * USB Serial Converter Generic functions
   3  *
   4  * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License version
   8  *      2 as published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/slab.h>
  15 #include <linux/sysrq.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_flip.h>
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/usb.h>
  21 #include <linux/usb/serial.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/kfifo.h>
  24 #include <linux/serial.h>
  25
  26 static int debug;
  27
  28 #ifdef CONFIG_USB_SERIAL_GENERIC
  29
  30 static int generic_probe(struct usb_interface *interface,
  31                          const struct usb_device_id *id);
  32
  33 static __u16 vendor  = 0x05f9;
  34 static __u16 product = 0xffff;
  35
  36 module_param(vendor, ushort, 0);
  37 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
  38
  39 module_param(product, ushort, 0);
  40 MODULE_PARM_DESC(product, "User specified USB idProduct");
  41
  42 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
  43
  44 /* we want to look at all devices, as the vendor/product id can change
  45  * depending on the command line argument */
  46 static const struct usb_device_id generic_serial_ids[] = {
  47         {.driver_info = 42},
  48         {}
  49 };
  50
  51 static struct usb_driver generic_driver = {
  52         .name =         "usbserial_generic",
  53         .probe =        generic_probe,
  54         .disconnect =   usb_serial_disconnect,
  55         .id_table =     generic_serial_ids,
  56         .no_dynamic_id =        1,
  57 };
  58
  59 /* All of the device info needed for the Generic Serial Converter */
  60 struct usb_serial_driver usb_serial_generic_device = {
  61         .driver = {
  62                 .owner =        THIS_MODULE,
  63                 .name =         "generic",
  64         },
  65         .id_table =             generic_device_ids,
  66         .usb_driver =           &generic_driver,
  67         .num_ports =            1,
  68         .disconnect =           usb_serial_generic_disconnect,
  69         .release =              usb_serial_generic_release,
  70         .throttle =             usb_serial_generic_throttle,
  71         .unthrottle =           usb_serial_generic_unthrottle,
  72         .resume =               usb_serial_generic_resume,
  73 };
  74
  75 static int generic_probe(struct usb_interface *interface,
  76                                const struct usb_device_id *id)
  77 {
  78         const struct usb_device_id *id_pattern;
  79
  80         id_pattern = usb_match_id(interface, generic_device_ids);
  81         if (id_pattern != NULL)
  82                 return usb_serial_probe(interface, id);
  83         return -ENODEV;
  84 }
  85 #endif
  86
  87 int usb_serial_generic_register(int _debug)
  88 {
  89         int retval = 0;
  90
  91         debug = _debug;
  92 #ifdef CONFIG_USB_SERIAL_GENERIC
  93         generic_device_ids[0].idVendor = vendor;
  94         generic_device_ids[0].idProduct = product;
  95         generic_device_ids[0].match_flags =
  96                 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  97
  98         /* register our generic driver with ourselves */
  99         retval = usb_serial_register(&usb_serial_generic_device);
 100         if (retval)
 101                 goto exit;
 102         retval = usb_register(&generic_driver);
 103         if (retval)
 104                 usb_serial_deregister(&usb_serial_generic_device);
 105 exit:
 106 #endif
 107         return retval;
 108 }
 109
 110 void usb_serial_generic_deregister(void)
 111 {
 112 #ifdef CONFIG_USB_SERIAL_GENERIC
 113         /* remove our generic driver */
 114         usb_deregister(&generic_driver);
 115         usb_serial_deregister(&usb_serial_generic_device);
 116 #endif
 117 }
 118
 119 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
 120 {
 121         int result = 0;
 122         unsigned long flags;
 123
 124         dbg("%s - port %d", __func__, port->number);
 125
 126         /* clear the throttle flags */
 127         spin_lock_irqsave(&port->lock, flags);
 128         port->throttled = 0;
 129         port->throttle_req = 0;
 130         spin_unlock_irqrestore(&port->lock, flags);
 131
 132         /* if we have a bulk endpoint, start reading from it */
 133         if (port->bulk_in_size)
 134                 result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
 135
 136         return result;
 137 }
 138 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 139
 140 static void generic_cleanup(struct usb_serial_port *port)
 141 {
 142         struct usb_serial *serial = port->serial;
 143         unsigned long flags;
 144
 145         dbg("%s - port %d", __func__, port->number);
 146
 147         if (serial->dev) {
 148                 /* shutdown any bulk transfers that might be going on */
 149                 if (port->bulk_out_size) {
 150                         usb_kill_urb(port->write_urb);
 151
 152                         spin_lock_irqsave(&port->lock, flags);
 153                         kfifo_reset_out(&port->write_fifo);
 154                         spin_unlock_irqrestore(&port->lock, flags);
 155                 }
 156                 if (port->bulk_in_size)
 157                         usb_kill_urb(port->read_urb);
 158         }
 159 }
 160
 161 void usb_serial_generic_close(struct usb_serial_port *port)
 162 {
 163         dbg("%s - port %d", __func__, port->number);
 164         generic_cleanup(port);
 165 }
 166 EXPORT_SYMBOL_GPL(usb_serial_generic_close);
 167
 168 static int usb_serial_multi_urb_write(struct tty_struct *tty,
 169         struct usb_serial_port *port, const unsigned char *buf, int count)
 170 {
 171         unsigned long flags;
 172         struct urb *urb;
 173         unsigned char *buffer;
 174         int status;
 175         int towrite;
 176         int bwrite = 0;
 177
 178         dbg("%s - port %d", __func__, port->number);
 179
 180         if (count == 0)
 181                 dbg("%s - write request of 0 bytes", __func__);
 182
 183         while (count > 0) {
 184                 towrite = (count > port->bulk_out_size) ?
 185                         port->bulk_out_size : count;
 186                 spin_lock_irqsave(&port->lock, flags);
 187                 if (port->urbs_in_flight >
 188                     port->serial->type->max_in_flight_urbs) {
 189                         spin_unlock_irqrestore(&port->lock, flags);
 190                         dbg("%s - write limit hit", __func__);
 191                         return bwrite;
 192                 }
 193                 port->tx_bytes_flight += towrite;
 194                 port->urbs_in_flight++;
 195                 spin_unlock_irqrestore(&port->lock, flags);
 196
 197                 buffer = kmalloc(towrite, GFP_ATOMIC);
 198                 if (!buffer) {
 199                         dev_err(&port->dev,
 200                         "%s ran out of kernel memory for urb ...\n", __func__);
 201                         goto error_no_buffer;
 202                 }
 203
 204                 urb = usb_alloc_urb(0, GFP_ATOMIC);
 205                 if (!urb) {
 206                         dev_err(&port->dev, "%s - no more free urbs\n",
 207                                 __func__);
 208                         goto error_no_urb;
 209                 }
 210
 211                 /* Copy data */
 212                 memcpy(buffer, buf + bwrite, towrite);
 213                 usb_serial_debug_data(debug, &port->dev, __func__,
 214                                       towrite, buffer);
 215                 /* fill the buffer and send it */
 216                 usb_fill_bulk_urb(urb, port->serial->dev,
 217                         usb_sndbulkpipe(port->serial->dev,
 218                                         port->bulk_out_endpointAddress),
 219                         buffer, towrite,
 220                         usb_serial_generic_write_bulk_callback, port);
 221
 222                 status = usb_submit_urb(urb, GFP_ATOMIC);
 223                 if (status) {
 224                         dev_err(&port->dev, "%s - error submitting urb: %d\n",
 225                                 __func__, status);
 226                         goto error;
 227                 }
 228
 229                 /* This urb is the responsibility of the host driver now */
 230                 usb_free_urb(urb);
 231                 dbg("%s write: %d", __func__, towrite);
 232                 count -= towrite;
 233                 bwrite += towrite;
 234         }
 235         return bwrite;
 236
 237 error:
 238         usb_free_urb(urb);
 239 error_no_urb:
 240         kfree(buffer);
 241 error_no_buffer:
 242         spin_lock_irqsave(&port->lock, flags);
 243         port->urbs_in_flight--;
 244         port->tx_bytes_flight -= towrite;
 245         spin_unlock_irqrestore(&port->lock, flags);
 246         return bwrite;
 247 }
 248
 249 /**
 250  * usb_serial_generic_write_start - kick off an URB write
 251  * @port:       Pointer to the &struct usb_serial_port data
 252  *
 253  * Returns the number of bytes queued on success. This will be zero if there
 254  * was nothing to send. Otherwise, it returns a negative errno value
 255  */
 256 static int usb_serial_generic_write_start(struct usb_serial_port *port)
 257 {
 258         unsigned char *data;
 259         int result;
 260         int count;
 261         unsigned long flags;
 262
 263         spin_lock_irqsave(&port->lock, flags);
 264         if (port->write_urb_busy || !kfifo_len(&port->write_fifo)) {
 265                 spin_unlock_irqrestore(&port->lock, flags);
 266                 return 0;
 267         }
 268         port->write_urb_busy = 1;
 269         spin_unlock_irqrestore(&port->lock, flags);
 270
 271         data = port->write_urb->transfer_buffer;
 272         count = kfifo_out_locked(&port->write_fifo, data, port->bulk_out_size, &port->lock);
 273         usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 274
 275         port->write_urb->transfer_buffer_length = count;
 276
 277         /* send the data out the bulk port */
 278         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 279         if (result) {
 280                 dev_err(&port->dev, "%s - error submitting urb: %d\n",
 281                                                 __func__, result);
 282                 /* don't have to grab the lock here, as we will
 283                    retry if != 0 */
 284                 port->write_urb_busy = 0;
 285                 return result;
 286         }
 287
 288         spin_lock_irqsave(&port->lock, flags);
 289         port->tx_bytes_flight += count;
 290         spin_unlock_irqrestore(&port->lock, flags);
 291
 292         return count;
 293 }
 294
 295 /**
 296  * usb_serial_generic_write - generic write function for serial USB devices
 297  * @tty:        Pointer to &struct tty_struct for the device
 298  * @port:       Pointer to the &usb_serial_port structure for the device
 299  * @buf:        Pointer to the data to write
 300  * @count:      Number of bytes to write
 301  *
 302  * Returns the number of characters actually written, which may be anything
 303  * from zero to @count. If an error occurs, it returns the negative errno
 304  * value.
 305  */
 306 int usb_serial_generic_write(struct tty_struct *tty,
 307         struct usb_serial_port *port, const unsigned char *buf, int count)
 308 {
 309         struct usb_serial *serial = port->serial;
 310         int result;
 311
 312         dbg("%s - port %d", __func__, port->number);
 313
 314         /* only do something if we have a bulk out endpoint */
 315         if (!port->bulk_out_size)
 316                 return -ENODEV;
 317
 318         if (!count)
 319                 return 0;
 320
 321         if (serial->type->max_in_flight_urbs)
 322                 return usb_serial_multi_urb_write(tty, port,
 323                                                   buf, count);
 324
 325         count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
 326         result = usb_serial_generic_write_start(port);
 327
 328         if (result >= 0)
 329                 result = count;
 330
 331         return result;
 332 }
 333 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
 334
 335 int usb_serial_generic_write_room(struct tty_struct *tty)
 336 {
 337         struct usb_serial_port *port = tty->driver_data;
 338         struct usb_serial *serial = port->serial;
 339         unsigned long flags;
 340         int room = 0;
 341
 342         dbg("%s - port %d", __func__, port->number);
 343
 344         if (!port->bulk_out_size)
 345                 return 0;
 346
 347         spin_lock_irqsave(&port->lock, flags);
 348         if (serial->type->max_in_flight_urbs) {
 349                 if (port->urbs_in_flight < serial->type->max_in_flight_urbs)
 350                         room = port->bulk_out_size *
 351                                 (serial->type->max_in_flight_urbs -
 352                                  port->urbs_in_flight);
 353         } else {
 354                 room = kfifo_avail(&port->write_fifo);
 355         }
 356         spin_unlock_irqrestore(&port->lock, flags);
 357
 358         dbg("%s - returns %d", __func__, room);
 359         return room;
 360 }
 361
 362 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 363 {
 364         struct usb_serial_port *port = tty->driver_data;
 365         struct usb_serial *serial = port->serial;
 366         unsigned long flags;
 367         int chars;
 368
 369         dbg("%s - port %d", __func__, port->number);
 370
 371         if (!port->bulk_out_size)
 372                 return 0;
 373
 374         spin_lock_irqsave(&port->lock, flags);
 375         if (serial->type->max_in_flight_urbs)
 376                 chars = port->tx_bytes_flight;
 377         else
 378                 chars = kfifo_len(&port->write_fifo) + port->tx_bytes_flight;
 379         spin_unlock_irqrestore(&port->lock, flags);
 380
 381         dbg("%s - returns %d", __func__, chars);
 382         return chars;
 383 }
 384
 385 int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
 386                                         gfp_t mem_flags)
 387 {
 388         int result;
 389
 390         result = usb_submit_urb(port->read_urb, mem_flags);
 391         if (result && result != -EPERM) {
 392                 dev_err(&port->dev, "%s - error submitting urb: %d\n",
 393                                                         __func__, result);
 394         }
 395         return result;
 396 }
 397 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
 398
 399 void usb_serial_generic_process_read_urb(struct urb *urb)
 400 {
 401         struct usb_serial_port *port = urb->context;
 402         struct tty_struct *tty;
 403         char *ch = (char *)urb->transfer_buffer;
 404         int i;
 405
 406         tty = tty_port_tty_get(&port->port);
 407         if (!tty)
 408                 return;
 409
 410         /* The per character mucking around with sysrq path it too slow for
 411            stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
 412            where the USB serial is not a console anyway */
 413         if (!port->port.console || !port->sysrq)
 414                 tty_insert_flip_string(tty, ch, urb->actual_length);
 415         else {
 416                 for (i = 0; i < urb->actual_length; i++, ch++) {
 417                         if (!usb_serial_handle_sysrq_char(tty, port, *ch))
 418                                 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
 419                 }
 420         }
 421         tty_flip_buffer_push(tty);
 422         tty_kref_put(tty);
 423 }
 424 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
 425
 426 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 427 {
 428         struct usb_serial_port *port = urb->context;
 429         unsigned char *data = urb->transfer_buffer;
 430         int status = urb->status;
 431         unsigned long flags;
 432
 433         dbg("%s - port %d", __func__, port->number);
 434
 435         if (unlikely(status != 0)) {
 436                 dbg("%s - nonzero read bulk status received: %d",
 437                     __func__, status);
 438                 return;
 439         }
 440
 441         usb_serial_debug_data(debug, &port->dev, __func__,
 442                                                 urb->actual_length, data);
 443         port->serial->type->process_read_urb(urb);
 444
 445         /* Throttle the device if requested by tty */
 446         spin_lock_irqsave(&port->lock, flags);
 447         port->throttled = port->throttle_req;
 448         if (!port->throttled) {
 449                 spin_unlock_irqrestore(&port->lock, flags);
 450                 usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
 451         } else
 452                 spin_unlock_irqrestore(&port->lock, flags);
 453 }
 454 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 455
 456 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 457 {
 458         unsigned long flags;
 459         struct usb_serial_port *port = urb->context;
 460         int status = urb->status;
 461
 462         dbg("%s - port %d", __func__, port->number);
 463
 464         if (port->serial->type->max_in_flight_urbs) {
 465                 kfree(urb->transfer_buffer);
 466
 467                 spin_lock_irqsave(&port->lock, flags);
 468                 --port->urbs_in_flight;
 469                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 470                 if (port->urbs_in_flight < 0)
 471                         port->urbs_in_flight = 0;
 472                 spin_unlock_irqrestore(&port->lock, flags);
 473         } else {
 474                 spin_lock_irqsave(&port->lock, flags);
 475                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 476                 port->write_urb_busy = 0;
 477                 spin_unlock_irqrestore(&port->lock, flags);
 478
 479                 if (status) {
 480                         spin_lock_irqsave(&port->lock, flags);
 481                         kfifo_reset_out(&port->write_fifo);
 482                         spin_unlock_irqrestore(&port->lock, flags);
 483                 } else {
 484                         usb_serial_generic_write_start(port);
 485                 }
 486         }
 487
 488         if (status)
 489                 dbg("%s - non-zero urb status: %d", __func__, status);
 490
 491         usb_serial_port_softint(port);
 492 }
 493 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 494
 495 void usb_serial_generic_throttle(struct tty_struct *tty)
 496 {
 497         struct usb_serial_port *port = tty->driver_data;
 498         unsigned long flags;
 499
 500         dbg("%s - port %d", __func__, port->number);
 501
 502         /* Set the throttle request flag. It will be picked up
 503          * by usb_serial_generic_read_bulk_callback(). */
 504         spin_lock_irqsave(&port->lock, flags);
 505         port->throttle_req = 1;
 506         spin_unlock_irqrestore(&port->lock, flags);
 507 }
 508 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
 509
 510 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 511 {
 512         struct usb_serial_port *port = tty->driver_data;
 513         int was_throttled;
 514
 515         dbg("%s - port %d", __func__, port->number);
 516
 517         /* Clear the throttle flags */
 518         spin_lock_irq(&port->lock);
 519         was_throttled = port->throttled;
 520         port->throttled = port->throttle_req = 0;
 521         spin_unlock_irq(&port->lock);
 522
 523         if (was_throttled)
 524                 usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
 525 }
 526 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
 527
 528 #ifdef CONFIG_MAGIC_SYSRQ
 529 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
 530                         struct usb_serial_port *port, unsigned int ch)
 531 {
 532         if (port->sysrq && port->port.console) {
 533                 if (ch && time_before(jiffies, port->sysrq)) {
 534                         handle_sysrq(ch, tty);
 535                         port->sysrq = 0;
 536                         return 1;
 537                 }
 538                 port->sysrq = 0;
 539         }
 540         return 0;
 541 }
 542 #else
 543 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
 544                         struct usb_serial_port *port, unsigned int ch)
 545 {
 546         return 0;
 547 }
 548 #endif
 549 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
 550
 551 int usb_serial_handle_break(struct usb_serial_port *port)
 552 {
 553         if (!port->sysrq) {
 554                 port->sysrq = jiffies + HZ*5;
 555                 return 1;
 556         }
 557         port->sysrq = 0;
 558         return 0;
 559 }
 560 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
 561
 562 int usb_serial_generic_resume(struct usb_serial *serial)
 563 {
 564         struct usb_serial_port *port;
 565         int i, c = 0, r;
 566
 567         for (i = 0; i < serial->num_ports; i++) {
 568                 port = serial->port[i];
 569                 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 570                         continue;
 571
 572                 if (port->read_urb) {
 573                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 574                         if (r < 0)
 575                                 c++;
 576                 }
 577
 578                 if (port->write_urb) {
 579                         r = usb_serial_generic_write_start(port);
 580                         if (r < 0)
 581                                 c++;
 582                 }
 583         }
 584
 585         return c ? -EIO : 0;
 586 }
 587 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
 588
 589 void usb_serial_generic_disconnect(struct usb_serial *serial)
 590 {
 591         int i;
 592
 593         dbg("%s", __func__);
 594
 595         /* stop reads and writes on all ports */
 596         for (i = 0; i < serial->num_ports; ++i)
 597                 generic_cleanup(serial->port[i]);
 598 }
 599
 600 void usb_serial_generic_release(struct usb_serial *serial)
 601 {
 602         dbg("%s", __func__);
 603 }