SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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,
 225                                 "%s - failed submitting write urb, error %d\n",
 226                                 __func__, status);
 227                         goto error;
 228                 }
 229
 230                 /* This urb is the responsibility of the host driver now */
 231                 usb_free_urb(urb);
 232                 dbg("%s write: %d", __func__, towrite);
 233                 count -= towrite;
 234                 bwrite += towrite;
 235         }
 236         return bwrite;
 237
 238 error:
 239         usb_free_urb(urb);
 240 error_no_urb:
 241         kfree(buffer);
 242 error_no_buffer:
 243         spin_lock_irqsave(&port->lock, flags);
 244         port->urbs_in_flight--;
 245         port->tx_bytes_flight -= towrite;
 246         spin_unlock_irqrestore(&port->lock, flags);
 247         return bwrite;
 248 }
 249
 250 /**
 251  * usb_serial_generic_write_start - kick off an URB write
 252  * @port:       Pointer to the &struct usb_serial_port data
 253  *
 254  * Returns the number of bytes queued on success. This will be zero if there
 255  * was nothing to send. Otherwise, it returns a negative errno value
 256  */
 257 static int usb_serial_generic_write_start(struct usb_serial_port *port)
 258 {
 259         struct usb_serial *serial = port->serial;
 260         unsigned char *data;
 261         int result;
 262         int count;
 263         unsigned long flags;
 264         bool start_io;
 265
 266         /* Atomically determine whether we can and need to start a USB
 267          * operation. */
 268         spin_lock_irqsave(&port->lock, flags);
 269         if (port->write_urb_busy)
 270                 start_io = false;
 271         else {
 272                 start_io = (kfifo_len(&port->write_fifo) != 0);
 273                 port->write_urb_busy = start_io;
 274         }
 275         spin_unlock_irqrestore(&port->lock, flags);
 276
 277         if (!start_io)
 278                 return 0;
 279
 280         data = port->write_urb->transfer_buffer;
 281         count = kfifo_out_locked(&port->write_fifo, data, port->bulk_out_size, &port->lock);
 282         usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 283
 284         /* set up our urb */
 285         usb_fill_bulk_urb(port->write_urb, serial->dev,
 286                            usb_sndbulkpipe(serial->dev,
 287                                 port->bulk_out_endpointAddress),
 288                            port->write_urb->transfer_buffer, count,
 289                            ((serial->type->write_bulk_callback) ?
 290                              serial->type->write_bulk_callback :
 291                              usb_serial_generic_write_bulk_callback),
 292                            port);
 293
 294         /* send the data out the bulk port */
 295         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 296         if (result) {
 297                 dev_err(&port->dev,
 298                         "%s - failed submitting write urb, error %d\n",
 299                                                 __func__, result);
 300                 /* don't have to grab the lock here, as we will
 301                    retry if != 0 */
 302                 port->write_urb_busy = 0;
 303                 return result;
 304         }
 305
 306         spin_lock_irqsave(&port->lock, flags);
 307         port->tx_bytes_flight += count;
 308         spin_unlock_irqrestore(&port->lock, flags);
 309
 310         return count;
 311 }
 312
 313 /**
 314  * usb_serial_generic_write - generic write function for serial USB devices
 315  * @tty:        Pointer to &struct tty_struct for the device
 316  * @port:       Pointer to the &usb_serial_port structure for the device
 317  * @buf:        Pointer to the data to write
 318  * @count:      Number of bytes to write
 319  *
 320  * Returns the number of characters actually written, which may be anything
 321  * from zero to @count. If an error occurs, it returns the negative errno
 322  * value.
 323  */
 324 int usb_serial_generic_write(struct tty_struct *tty,
 325         struct usb_serial_port *port, const unsigned char *buf, int count)
 326 {
 327         struct usb_serial *serial = port->serial;
 328         int result;
 329
 330         dbg("%s - port %d", __func__, port->number);
 331
 332         /* only do something if we have a bulk out endpoint */
 333         if (!port->bulk_out_size)
 334                 return -ENODEV;
 335
 336         if (count == 0) {
 337                 dbg("%s - write request of 0 bytes", __func__);
 338                 return 0;
 339         }
 340
 341         if (serial->type->max_in_flight_urbs)
 342                 return usb_serial_multi_urb_write(tty, port,
 343                                                   buf, count);
 344
 345         count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
 346         result = usb_serial_generic_write_start(port);
 347
 348         if (result >= 0)
 349                 result = count;
 350
 351         return result;
 352 }
 353 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
 354
 355 int usb_serial_generic_write_room(struct tty_struct *tty)
 356 {
 357         struct usb_serial_port *port = tty->driver_data;
 358         struct usb_serial *serial = port->serial;
 359         unsigned long flags;
 360         int room = 0;
 361
 362         dbg("%s - port %d", __func__, port->number);
 363
 364         if (!port->bulk_out_size)
 365                 return 0;
 366
 367         spin_lock_irqsave(&port->lock, flags);
 368         if (serial->type->max_in_flight_urbs) {
 369                 if (port->urbs_in_flight < serial->type->max_in_flight_urbs)
 370                         room = port->bulk_out_size *
 371                                 (serial->type->max_in_flight_urbs -
 372                                  port->urbs_in_flight);
 373         } else {
 374                 room = kfifo_avail(&port->write_fifo);
 375         }
 376         spin_unlock_irqrestore(&port->lock, flags);
 377
 378         dbg("%s - returns %d", __func__, room);
 379         return room;
 380 }
 381
 382 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 383 {
 384         struct usb_serial_port *port = tty->driver_data;
 385         struct usb_serial *serial = port->serial;
 386         unsigned long flags;
 387         int chars;
 388
 389         dbg("%s - port %d", __func__, port->number);
 390
 391         if (!port->bulk_out_size)
 392                 return 0;
 393
 394         spin_lock_irqsave(&port->lock, flags);
 395         if (serial->type->max_in_flight_urbs)
 396                 chars = port->tx_bytes_flight;
 397         else
 398                 chars = kfifo_len(&port->write_fifo) + port->tx_bytes_flight;
 399         spin_unlock_irqrestore(&port->lock, flags);
 400
 401         dbg("%s - returns %d", __func__, chars);
 402         return chars;
 403 }
 404
 405 int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
 406                                         gfp_t mem_flags)
 407 {
 408         struct urb *urb = port->read_urb;
 409         struct usb_serial *serial = port->serial;
 410         int result;
 411
 412         /* Continue reading from device */
 413         usb_fill_bulk_urb(urb, serial->dev,
 414                            usb_rcvbulkpipe(serial->dev,
 415                                         port->bulk_in_endpointAddress),
 416                            urb->transfer_buffer,
 417                            urb->transfer_buffer_length,
 418                            ((serial->type->read_bulk_callback) ?
 419                              serial->type->read_bulk_callback :
 420                              usb_serial_generic_read_bulk_callback), port);
 421
 422         result = usb_submit_urb(urb, mem_flags);
 423         if (result && result != -EPERM) {
 424                 dev_err(&port->dev,
 425                         "%s - failed submitting read urb, error %d\n",
 426                                                         __func__, result);
 427         }
 428         return result;
 429 }
 430 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
 431
 432 /* Push data to tty layer and resubmit the bulk read URB */
 433 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 434 {
 435         struct urb *urb = port->read_urb;
 436         struct tty_struct *tty = tty_port_tty_get(&port->port);
 437         char *ch = (char *)urb->transfer_buffer;
 438         int i;
 439
 440         if (!tty)
 441                 goto done;
 442
 443         /* The per character mucking around with sysrq path it too slow for
 444            stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
 445            where the USB serial is not a console anyway */
 446         if (!port->port.console || !port->sysrq)
 447                 tty_insert_flip_string(tty, ch, urb->actual_length);
 448         else {
 449                 /* Push data to tty */
 450                 for (i = 0; i < urb->actual_length; i++, ch++) {
 451                         if (!usb_serial_handle_sysrq_char(tty, port, *ch))
 452                                 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
 453                 }
 454         }
 455         tty_flip_buffer_push(tty);
 456         tty_kref_put(tty);
 457 done:
 458         usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
 459 }
 460
 461 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 462 {
 463         struct usb_serial_port *port = urb->context;
 464         unsigned char *data = urb->transfer_buffer;
 465         int status = urb->status;
 466         unsigned long flags;
 467
 468         dbg("%s - port %d", __func__, port->number);
 469
 470         if (unlikely(status != 0)) {
 471                 dbg("%s - nonzero read bulk status received: %d",
 472                     __func__, status);
 473                 return;
 474         }
 475
 476         usb_serial_debug_data(debug, &port->dev, __func__,
 477                                                 urb->actual_length, data);
 478
 479         /* Throttle the device if requested by tty */
 480         spin_lock_irqsave(&port->lock, flags);
 481         port->throttled = port->throttle_req;
 482         if (!port->throttled) {
 483                 spin_unlock_irqrestore(&port->lock, flags);
 484                 flush_and_resubmit_read_urb(port);
 485         } else
 486                 spin_unlock_irqrestore(&port->lock, flags);
 487 }
 488 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 489
 490 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 491 {
 492         unsigned long flags;
 493         struct usb_serial_port *port = urb->context;
 494         int status = urb->status;
 495
 496         dbg("%s - port %d", __func__, port->number);
 497
 498         if (port->serial->type->max_in_flight_urbs) {
 499                 kfree(urb->transfer_buffer);
 500
 501                 spin_lock_irqsave(&port->lock, flags);
 502                 --port->urbs_in_flight;
 503                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 504                 if (port->urbs_in_flight < 0)
 505                         port->urbs_in_flight = 0;
 506                 spin_unlock_irqrestore(&port->lock, flags);
 507         } else {
 508                 spin_lock_irqsave(&port->lock, flags);
 509                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 510                 port->write_urb_busy = 0;
 511                 spin_unlock_irqrestore(&port->lock, flags);
 512
 513                 if (status) {
 514                         spin_lock_irqsave(&port->lock, flags);
 515                         kfifo_reset_out(&port->write_fifo);
 516                         spin_unlock_irqrestore(&port->lock, flags);
 517                 } else {
 518                         usb_serial_generic_write_start(port);
 519                 }
 520         }
 521
 522         if (status)
 523                 dbg("%s - non-zero urb status: %d", __func__, status);
 524
 525         usb_serial_port_softint(port);
 526 }
 527 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 528
 529 void usb_serial_generic_throttle(struct tty_struct *tty)
 530 {
 531         struct usb_serial_port *port = tty->driver_data;
 532         unsigned long flags;
 533
 534         dbg("%s - port %d", __func__, port->number);
 535
 536         /* Set the throttle request flag. It will be picked up
 537          * by usb_serial_generic_read_bulk_callback(). */
 538         spin_lock_irqsave(&port->lock, flags);
 539         port->throttle_req = 1;
 540         spin_unlock_irqrestore(&port->lock, flags);
 541 }
 542
 543 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 544 {
 545         struct usb_serial_port *port = tty->driver_data;
 546         int was_throttled;
 547         unsigned long flags;
 548
 549         dbg("%s - port %d", __func__, port->number);
 550
 551         /* Clear the throttle flags */
 552         spin_lock_irqsave(&port->lock, flags);
 553         was_throttled = port->throttled;
 554         port->throttled = port->throttle_req = 0;
 555         spin_unlock_irqrestore(&port->lock, flags);
 556
 557         if (was_throttled) {
 558                 /* Resume reading from device */
 559                 flush_and_resubmit_read_urb(port);
 560         }
 561 }
 562
 563 #ifdef CONFIG_MAGIC_SYSRQ
 564 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
 565                         struct usb_serial_port *port, unsigned int ch)
 566 {
 567         if (port->sysrq && port->port.console) {
 568                 if (ch && time_before(jiffies, port->sysrq)) {
 569                         handle_sysrq(ch, tty);
 570                         port->sysrq = 0;
 571                         return 1;
 572                 }
 573                 port->sysrq = 0;
 574         }
 575         return 0;
 576 }
 577 #else
 578 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
 579                         struct usb_serial_port *port, unsigned int ch)
 580 {
 581         return 0;
 582 }
 583 #endif
 584 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
 585
 586 int usb_serial_handle_break(struct usb_serial_port *port)
 587 {
 588         if (!port->sysrq) {
 589                 port->sysrq = jiffies + HZ*5;
 590                 return 1;
 591         }
 592         port->sysrq = 0;
 593         return 0;
 594 }
 595 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
 596
 597 int usb_serial_generic_resume(struct usb_serial *serial)
 598 {
 599         struct usb_serial_port *port;
 600         int i, c = 0, r;
 601
 602         for (i = 0; i < serial->num_ports; i++) {
 603                 port = serial->port[i];
 604                 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 605                         continue;
 606
 607                 if (port->read_urb) {
 608                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 609                         if (r < 0)
 610                                 c++;
 611                 }
 612
 613                 if (port->write_urb) {
 614                         r = usb_serial_generic_write_start(port);
 615                         if (r < 0)
 616                                 c++;
 617                 }
 618         }
 619
 620         return c ? -EIO : 0;
 621 }
 622 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
 623
 624 void usb_serial_generic_disconnect(struct usb_serial *serial)
 625 {
 626         int i;
 627
 628         dbg("%s", __func__);
 629
 630         /* stop reads and writes on all ports */
 631         for (i = 0; i < serial->num_ports; ++i)
 632                 generic_cleanup(serial->port[i]);
 633 }
 634
 635 void usb_serial_generic_release(struct usb_serial *serial)
 636 {
 637         dbg("%s", __func__);
 638 }