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         .disconnect =           usb_serial_generic_disconnect,
  67         .release =              usb_serial_generic_release,
  68         .throttle =             usb_serial_generic_throttle,
  69         .unthrottle =           usb_serial_generic_unthrottle,
  70         .resume =               usb_serial_generic_resume,
  71 };
  72
  73 static int generic_probe(struct usb_interface *interface,
  74                                const struct usb_device_id *id)
  75 {
  76         const struct usb_device_id *id_pattern;
  77
  78         id_pattern = usb_match_id(interface, generic_device_ids);
  79         if (id_pattern != NULL)
  80                 return usb_serial_probe(interface, id);
  81         return -ENODEV;
  82 }
  83 #endif
  84
  85 int usb_serial_generic_register(int _debug)
  86 {
  87         int retval = 0;
  88
  89         debug = _debug;
  90 #ifdef CONFIG_USB_SERIAL_GENERIC
  91         generic_device_ids[0].idVendor = vendor;
  92         generic_device_ids[0].idProduct = product;
  93         generic_device_ids[0].match_flags =
  94                 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  95
  96         /* register our generic driver with ourselves */
  97         retval = usb_serial_register(&usb_serial_generic_device);
  98         if (retval)
  99                 goto exit;
 100         retval = usb_register(&generic_driver);
 101         if (retval)
 102                 usb_serial_deregister(&usb_serial_generic_device);
 103 exit:
 104 #endif
 105         return retval;
 106 }
 107
 108 void usb_serial_generic_deregister(void)
 109 {
 110 #ifdef CONFIG_USB_SERIAL_GENERIC
 111         /* remove our generic driver */
 112         usb_deregister(&generic_driver);
 113         usb_serial_deregister(&usb_serial_generic_device);
 114 #endif
 115 }
 116
 117 int usb_serial_generic_open(struct tty_struct *tty,
 118                         struct usb_serial_port *port, struct file *filp)
 119 {
 120         struct usb_serial *serial = port->serial;
 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 (serial->num_bulk_in) {
 134                 /* Start reading from the device */
 135                 usb_fill_bulk_urb(port->read_urb, serial->dev,
 136                                    usb_rcvbulkpipe(serial->dev,
 137                                                 port->bulk_in_endpointAddress),
 138                                    port->read_urb->transfer_buffer,
 139                                    port->read_urb->transfer_buffer_length,
 140                                    ((serial->type->read_bulk_callback) ?
 141                                      serial->type->read_bulk_callback :
 142                                      usb_serial_generic_read_bulk_callback),
 143                                    port);
 144                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 145                 if (result)
 146                         dev_err(&port->dev,
 147                             "%s - failed resubmitting read urb, error %d\n",
 148                                                         __func__, result);
 149         }
 150
 151         return result;
 152 }
 153 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 154
 155 static void generic_cleanup(struct usb_serial_port *port)
 156 {
 157         struct usb_serial *serial = port->serial;
 158
 159         dbg("%s - port %d", __func__, port->number);
 160
 161         if (serial->dev) {
 162                 /* shutdown any bulk reads that might be going on */
 163                 if (serial->num_bulk_out)
 164                         usb_kill_urb(port->write_urb);
 165                 if (serial->num_bulk_in)
 166                         usb_kill_urb(port->read_urb);
 167         }
 168 }
 169
 170 int usb_serial_generic_resume(struct usb_serial *serial)
 171 {
 172         struct usb_serial_port *port;
 173         int i, c = 0, r;
 174
 175         for (i = 0; i < serial->num_ports; i++) {
 176                 port = serial->port[i];
 177                 if (port->port.count && port->read_urb) {
 178                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 179                         if (r < 0)
 180                                 c++;
 181                 }
 182         }
 183
 184         return c ? -EIO : 0;
 185 }
 186 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
 187
 188 void usb_serial_generic_close(struct usb_serial_port *port)
 189 {
 190         dbg("%s - port %d", __func__, port->number);
 191         generic_cleanup(port);
 192 }
 193
 194 static int usb_serial_multi_urb_write(struct tty_struct *tty,
 195         struct usb_serial_port *port, const unsigned char *buf, int count)
 196 {
 197         unsigned long flags;
 198         struct urb *urb;
 199         unsigned char *buffer;
 200         int status;
 201         int towrite;
 202         int bwrite = 0;
 203
 204         dbg("%s - port %d", __func__, port->number);
 205
 206         if (count == 0)
 207                 dbg("%s - write request of 0 bytes", __func__);
 208
 209         while (count > 0) {
 210                 towrite = (count > port->bulk_out_size) ?
 211                         port->bulk_out_size : count;
 212                 spin_lock_irqsave(&port->lock, flags);
 213                 if (port->urbs_in_flight >
 214                     port->serial->type->max_in_flight_urbs) {
 215                         spin_unlock_irqrestore(&port->lock, flags);
 216                         dbg("%s - write limit hit\n", __func__);
 217                         return bwrite;
 218                 }
 219                 port->tx_bytes_flight += towrite;
 220                 port->urbs_in_flight++;
 221                 spin_unlock_irqrestore(&port->lock, flags);
 222
 223                 buffer = kmalloc(towrite, GFP_ATOMIC);
 224                 if (!buffer) {
 225                         dev_err(&port->dev,
 226                         "%s ran out of kernel memory for urb ...\n", __func__);
 227                         goto error_no_buffer;
 228                 }
 229
 230                 urb = usb_alloc_urb(0, GFP_ATOMIC);
 231                 if (!urb) {
 232                         dev_err(&port->dev, "%s - no more free urbs\n",
 233                                 __func__);
 234                         goto error_no_urb;
 235                 }
 236
 237                 /* Copy data */
 238                 memcpy(buffer, buf + bwrite, towrite);
 239                 usb_serial_debug_data(debug, &port->dev, __func__,
 240                                       towrite, buffer);
 241                 /* fill the buffer and send it */
 242                 usb_fill_bulk_urb(urb, port->serial->dev,
 243                         usb_sndbulkpipe(port->serial->dev,
 244                                         port->bulk_out_endpointAddress),
 245                         buffer, towrite,
 246                         usb_serial_generic_write_bulk_callback, port);
 247
 248                 status = usb_submit_urb(urb, GFP_ATOMIC);
 249                 if (status) {
 250                         dev_err(&port->dev,
 251                                 "%s - failed submitting write urb, error %d\n",
 252                                 __func__, status);
 253                         goto error;
 254                 }
 255
 256                 /* This urb is the responsibility of the host driver now */
 257                 usb_free_urb(urb);
 258                 dbg("%s write: %d", __func__, towrite);
 259                 count -= towrite;
 260                 bwrite += towrite;
 261         }
 262         return bwrite;
 263
 264 error:
 265         usb_free_urb(urb);
 266 error_no_urb:
 267         kfree(buffer);
 268 error_no_buffer:
 269         spin_lock_irqsave(&port->lock, flags);
 270         port->urbs_in_flight--;
 271         port->tx_bytes_flight -= towrite;
 272         spin_unlock_irqrestore(&port->lock, flags);
 273         return bwrite;
 274 }
 275
 276 int usb_serial_generic_write(struct tty_struct *tty,
 277         struct usb_serial_port *port, const unsigned char *buf, int count)
 278 {
 279         struct usb_serial *serial = port->serial;
 280         int result;
 281         unsigned char *data;
 282
 283         dbg("%s - port %d", __func__, port->number);
 284
 285         if (count == 0) {
 286                 dbg("%s - write request of 0 bytes", __func__);
 287                 return 0;
 288         }
 289
 290         /* only do something if we have a bulk out endpoint */
 291         if (serial->num_bulk_out) {
 292                 unsigned long flags;
 293
 294                 if (serial->type->max_in_flight_urbs)
 295                         return usb_serial_multi_urb_write(tty, port,
 296                                                           buf, count);
 297
 298                 spin_lock_irqsave(&port->lock, flags);
 299                 if (port->write_urb_busy) {
 300                         spin_unlock_irqrestore(&port->lock, flags);
 301                         dbg("%s - already writing", __func__);
 302                         return 0;
 303                 }
 304                 port->write_urb_busy = 1;
 305                 spin_unlock_irqrestore(&port->lock, flags);
 306
 307                 count = (count > port->bulk_out_size) ?
 308                                         port->bulk_out_size : count;
 309
 310                 memcpy(port->write_urb->transfer_buffer, buf, count);
 311                 data = port->write_urb->transfer_buffer;
 312                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 313
 314                 /* set up our urb */
 315                 usb_fill_bulk_urb(port->write_urb, serial->dev,
 316                                    usb_sndbulkpipe(serial->dev,
 317                                         port->bulk_out_endpointAddress),
 318                                    port->write_urb->transfer_buffer, count,
 319                                    ((serial->type->write_bulk_callback) ?
 320                                      serial->type->write_bulk_callback :
 321                                      usb_serial_generic_write_bulk_callback),
 322                                    port);
 323
 324                 /* send the data out the bulk port */
 325                 port->write_urb_busy = 1;
 326                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 327                 if (result) {
 328                         dev_err(&port->dev,
 329                                 "%s - failed submitting write urb, error %d\n",
 330                                                         __func__, result);
 331                         /* don't have to grab the lock here, as we will
 332                            retry if != 0 */
 333                         port->write_urb_busy = 0;
 334                 } else
 335                         result = count;
 336
 337                 return result;
 338         }
 339
 340         /* no bulk out, so return 0 bytes written */
 341         return 0;
 342 }
 343 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
 344
 345 int usb_serial_generic_write_room(struct tty_struct *tty)
 346 {
 347         struct usb_serial_port *port = tty->driver_data;
 348         struct usb_serial *serial = port->serial;
 349         unsigned long flags;
 350         int room = 0;
 351
 352         dbg("%s - port %d", __func__, port->number);
 353         spin_lock_irqsave(&port->lock, flags);
 354         if (serial->type->max_in_flight_urbs) {
 355                 if (port->urbs_in_flight < serial->type->max_in_flight_urbs)
 356                         room = port->bulk_out_size *
 357                                 (serial->type->max_in_flight_urbs -
 358                                  port->urbs_in_flight);
 359         } else if (serial->num_bulk_out && !(port->write_urb_busy)) {
 360                 room = port->bulk_out_size;
 361         }
 362         spin_unlock_irqrestore(&port->lock, flags);
 363
 364         dbg("%s - returns %d", __func__, room);
 365         return room;
 366 }
 367
 368 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 369 {
 370         struct usb_serial_port *port = tty->driver_data;
 371         struct usb_serial *serial = port->serial;
 372         int chars = 0;
 373         unsigned long flags;
 374
 375         dbg("%s - port %d", __func__, port->number);
 376
 377         if (serial->type->max_in_flight_urbs) {
 378                 spin_lock_irqsave(&port->lock, flags);
 379                 chars = port->tx_bytes_flight;
 380                 spin_unlock_irqrestore(&port->lock, flags);
 381         } else if (serial->num_bulk_out) {
 382                 /* FIXME: Locking */
 383                 if (port->write_urb_busy)
 384                         chars = port->write_urb->transfer_buffer_length;
 385         }
 386
 387         dbg("%s - returns %d", __func__, chars);
 388         return chars;
 389 }
 390
 391
 392 void usb_serial_generic_resubmit_read_urb(struct usb_serial_port *port,
 393                         gfp_t mem_flags)
 394 {
 395         struct urb *urb = port->read_urb;
 396         struct usb_serial *serial = port->serial;
 397         int result;
 398
 399         /* Continue reading from device */
 400         usb_fill_bulk_urb(urb, serial->dev,
 401                            usb_rcvbulkpipe(serial->dev,
 402                                         port->bulk_in_endpointAddress),
 403                            urb->transfer_buffer,
 404                            urb->transfer_buffer_length,
 405                            ((serial->type->read_bulk_callback) ?
 406                              serial->type->read_bulk_callback :
 407                              usb_serial_generic_read_bulk_callback), port);
 408         result = usb_submit_urb(urb, mem_flags);
 409         if (result)
 410                 dev_err(&port->dev,
 411                         "%s - failed resubmitting read urb, error %d\n",
 412                                                         __func__, result);
 413 }
 414 EXPORT_SYMBOL_GPL(usb_serial_generic_resubmit_read_urb);
 415
 416 /* Push data to tty layer and resubmit the bulk read URB */
 417 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 418 {
 419         struct urb *urb = port->read_urb;
 420         struct tty_struct *tty = tty_port_tty_get(&port->port);
 421         char *ch = (char *)urb->transfer_buffer;
 422         int i;
 423
 424         if (!tty)
 425                 goto done;
 426
 427         /* The per character mucking around with sysrq path it too slow for
 428            stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
 429            where the USB serial is not a console anyway */
 430         if (!port->console || !port->sysrq)
 431                 tty_insert_flip_string(tty, ch, urb->actual_length);
 432         else {
 433                 /* Push data to tty */
 434                 for (i = 0; i < urb->actual_length; i++, ch++) {
 435                         if (!usb_serial_handle_sysrq_char(tty, port, *ch))
 436                                 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
 437                 }
 438         }
 439         tty_flip_buffer_push(tty);
 440         tty_kref_put(tty);
 441 done:
 442         usb_serial_generic_resubmit_read_urb(port, GFP_ATOMIC);
 443 }
 444
 445 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 446 {
 447         struct usb_serial_port *port = urb->context;
 448         unsigned char *data = urb->transfer_buffer;
 449         int status = urb->status;
 450         unsigned long flags;
 451
 452         dbg("%s - port %d", __func__, port->number);
 453
 454         if (unlikely(status != 0)) {
 455                 dbg("%s - nonzero read bulk status received: %d",
 456                     __func__, status);
 457                 return;
 458         }
 459
 460         usb_serial_debug_data(debug, &port->dev, __func__,
 461                                                 urb->actual_length, data);
 462
 463         /* Throttle the device if requested by tty */
 464         spin_lock_irqsave(&port->lock, flags);
 465         port->throttled = port->throttle_req;
 466         if (!port->throttled) {
 467                 spin_unlock_irqrestore(&port->lock, flags);
 468                 flush_and_resubmit_read_urb(port);
 469         } else
 470                 spin_unlock_irqrestore(&port->lock, flags);
 471 }
 472 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 473
 474 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 475 {
 476         unsigned long flags;
 477         struct usb_serial_port *port = urb->context;
 478         int status = urb->status;
 479
 480         dbg("%s - port %d", __func__, port->number);
 481
 482         if (port->serial->type->max_in_flight_urbs) {
 483                 spin_lock_irqsave(&port->lock, flags);
 484                 --port->urbs_in_flight;
 485                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 486                 if (port->urbs_in_flight < 0)
 487                         port->urbs_in_flight = 0;
 488                 spin_unlock_irqrestore(&port->lock, flags);
 489         } else {
 490                 /* Handle the case for single urb mode */
 491                 port->write_urb_busy = 0;
 492         }
 493
 494         if (status) {
 495                 dbg("%s - nonzero write bulk status received: %d",
 496                     __func__, status);
 497                 return;
 498         }
 499         usb_serial_port_softint(port);
 500 }
 501 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 502
 503 void usb_serial_generic_throttle(struct tty_struct *tty)
 504 {
 505         struct usb_serial_port *port = tty->driver_data;
 506         unsigned long flags;
 507
 508         dbg("%s - port %d", __func__, port->number);
 509
 510         /* Set the throttle request flag. It will be picked up
 511          * by usb_serial_generic_read_bulk_callback(). */
 512         spin_lock_irqsave(&port->lock, flags);
 513         port->throttle_req = 1;
 514         spin_unlock_irqrestore(&port->lock, flags);
 515 }
 516
 517 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 518 {
 519         struct usb_serial_port *port = tty->driver_data;
 520         int was_throttled;
 521         unsigned long flags;
 522
 523         dbg("%s - port %d", __func__, port->number);
 524
 525         /* Clear the throttle flags */
 526         spin_lock_irqsave(&port->lock, flags);
 527         was_throttled = port->throttled;
 528         port->throttled = port->throttle_req = 0;
 529         spin_unlock_irqrestore(&port->lock, flags);
 530
 531         if (was_throttled) {
 532                 /* Resume reading from device */
 533                 usb_serial_generic_resubmit_read_urb(port, GFP_KERNEL);
 534         }
 535 }
 536
 537 int usb_serial_handle_sysrq_char(struct tty_struct *tty,
 538                         struct usb_serial_port *port, unsigned int ch)
 539 {
 540         if (port->sysrq && port->console) {
 541                 if (ch && time_before(jiffies, port->sysrq)) {
 542                         handle_sysrq(ch, tty);
 543                         port->sysrq = 0;
 544                         return 1;
 545                 }
 546                 port->sysrq = 0;
 547         }
 548         return 0;
 549 }
 550 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
 551
 552 int usb_serial_handle_break(struct usb_serial_port *port)
 553 {
 554         if (!port->sysrq) {
 555                 port->sysrq = jiffies + HZ*5;
 556                 return 1;
 557         }
 558         port->sysrq = 0;
 559         return 0;
 560 }
 561 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
 562
 563 void usb_serial_generic_disconnect(struct usb_serial *serial)
 564 {
 565         int i;
 566
 567         dbg("%s", __func__);
 568
 569         /* stop reads and writes on all ports */
 570         for (i = 0; i < serial->num_ports; ++i)
 571                 generic_cleanup(serial->port[i]);
 572 }
 573
 574 void usb_serial_generic_release(struct usb_serial *serial)
 575 {
 576         dbg("%s", __func__);
 577 }