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