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