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
 343 int usb_serial_generic_write_room(struct tty_struct *tty)
 344 {
 345         struct usb_serial_port *port = tty->driver_data;
 346         struct usb_serial *serial = port->serial;
 347         unsigned long flags;
 348         int room = 0;
 349
 350         dbg("%s - port %d", __func__, port->number);
 351         spin_lock_irqsave(&port->lock, flags);
 352         if (serial->type->max_in_flight_urbs) {
 353                 if (port->urbs_in_flight < serial->type->max_in_flight_urbs)
 354                         room = port->bulk_out_size;
 355         } else if (serial->num_bulk_out && !(port->write_urb_busy)) {
 356                 room = port->bulk_out_size;
 357         }
 358         spin_unlock_irqrestore(&port->lock, flags);
 359
 360         dbg("%s - returns %d", __func__, room);
 361         return room;
 362 }
 363
 364 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 365 {
 366         struct usb_serial_port *port = tty->driver_data;
 367         struct usb_serial *serial = port->serial;
 368         int chars = 0;
 369         unsigned long flags;
 370
 371         dbg("%s - port %d", __func__, port->number);
 372
 373         if (serial->type->max_in_flight_urbs) {
 374                 spin_lock_irqsave(&port->lock, flags);
 375                 chars = port->tx_bytes_flight;
 376                 spin_unlock_irqrestore(&port->lock, flags);
 377         } else if (serial->num_bulk_out) {
 378                 /* FIXME: Locking */
 379                 if (port->write_urb_busy)
 380                         chars = port->write_urb->transfer_buffer_length;
 381         }
 382
 383         dbg("%s - returns %d", __func__, chars);
 384         return chars;
 385 }
 386
 387
 388 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 389 {
 390         struct urb *urb = port->read_urb;
 391         struct usb_serial *serial = port->serial;
 392         int result;
 393
 394         /* Continue reading from device */
 395         usb_fill_bulk_urb(urb, serial->dev,
 396                            usb_rcvbulkpipe(serial->dev,
 397                                         port->bulk_in_endpointAddress),
 398                            urb->transfer_buffer,
 399                            urb->transfer_buffer_length,
 400                            ((serial->type->read_bulk_callback) ?
 401                              serial->type->read_bulk_callback :
 402                              usb_serial_generic_read_bulk_callback), port);
 403         result = usb_submit_urb(urb, mem_flags);
 404         if (result)
 405                 dev_err(&port->dev,
 406                         "%s - failed resubmitting read urb, error %d\n",
 407                                                         __func__, result);
 408 }
 409
 410 /* Push data to tty layer and resubmit the bulk read URB */
 411 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 412 {
 413         struct urb *urb = port->read_urb;
 414         struct tty_struct *tty = tty_port_tty_get(&port->port);
 415         int room;
 416
 417         /* Push data to tty */
 418         if (tty && urb->actual_length) {
 419                 room = tty_buffer_request_room(tty, urb->actual_length);
 420                 if (room) {
 421                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 422                         tty_flip_buffer_push(tty);
 423                 }
 424         }
 425         tty_kref_put(tty);
 426
 427         resubmit_read_urb(port, GFP_ATOMIC);
 428 }
 429
 430 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 431 {
 432         struct usb_serial_port *port = urb->context;
 433         unsigned char *data = urb->transfer_buffer;
 434         int status = urb->status;
 435         unsigned long flags;
 436
 437         dbg("%s - port %d", __func__, port->number);
 438
 439         if (unlikely(status != 0)) {
 440                 dbg("%s - nonzero read bulk status received: %d",
 441                     __func__, status);
 442                 return;
 443         }
 444
 445         usb_serial_debug_data(debug, &port->dev, __func__,
 446                                                 urb->actual_length, data);
 447
 448         /* Throttle the device if requested by tty */
 449         spin_lock_irqsave(&port->lock, flags);
 450         port->throttled = port->throttle_req;
 451         if (!port->throttled) {
 452                 spin_unlock_irqrestore(&port->lock, flags);
 453                 flush_and_resubmit_read_urb(port);
 454         } else
 455                 spin_unlock_irqrestore(&port->lock, flags);
 456 }
 457 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 458
 459 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 460 {
 461         unsigned long flags;
 462         struct usb_serial_port *port = urb->context;
 463         int status = urb->status;
 464
 465         dbg("%s - port %d", __func__, port->number);
 466
 467         if (port->serial->type->max_in_flight_urbs) {
 468                 spin_lock_irqsave(&port->lock, flags);
 469                 --port->urbs_in_flight;
 470                 port->tx_bytes_flight -= urb->transfer_buffer_length;
 471                 if (port->urbs_in_flight < 0)
 472                         port->urbs_in_flight = 0;
 473                 spin_unlock_irqrestore(&port->lock, flags);
 474         } else {
 475                 /* Handle the case for single urb mode */
 476                 port->write_urb_busy = 0;
 477         }
 478
 479         if (status) {
 480                 dbg("%s - nonzero write bulk status received: %d",
 481                     __func__, status);
 482                 return;
 483         }
 484         usb_serial_port_softint(port);
 485 }
 486 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 487
 488 void usb_serial_generic_throttle(struct tty_struct *tty)
 489 {
 490         struct usb_serial_port *port = tty->driver_data;
 491         unsigned long flags;
 492
 493         dbg("%s - port %d", __func__, port->number);
 494
 495         /* Set the throttle request flag. It will be picked up
 496          * by usb_serial_generic_read_bulk_callback(). */
 497         spin_lock_irqsave(&port->lock, flags);
 498         port->throttle_req = 1;
 499         spin_unlock_irqrestore(&port->lock, flags);
 500 }
 501
 502 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 503 {
 504         struct usb_serial_port *port = tty->driver_data;
 505         int was_throttled;
 506         unsigned long flags;
 507
 508         dbg("%s - port %d", __func__, port->number);
 509
 510         /* Clear the throttle flags */
 511         spin_lock_irqsave(&port->lock, flags);
 512         was_throttled = port->throttled;
 513         port->throttled = port->throttle_req = 0;
 514         spin_unlock_irqrestore(&port->lock, flags);
 515
 516         if (was_throttled) {
 517                 /* Resume reading from device */
 518                 resubmit_read_urb(port, GFP_KERNEL);
 519         }
 520 }
 521
 522 void usb_serial_generic_shutdown(struct usb_serial *serial)
 523 {
 524         int i;
 525
 526         dbg("%s", __func__);
 527
 528         /* stop reads and writes on all ports */
 529         for (i = 0; i < serial->num_ports; ++i)
 530                 generic_cleanup(serial->port[i]);
 531 }
 532