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         /* force low_latency on so that our tty_push actually forces the data
 126            through, otherwise it is scheduled, and with high data rates (like
 127            with OHCI) data can get lost. */
 128         if (tty)
 129                 tty->low_latency = 1;
 130
 131         /* clear the throttle flags */
 132         spin_lock_irqsave(&port->lock, flags);
 133         port->throttled = 0;
 134         port->throttle_req = 0;
 135         spin_unlock_irqrestore(&port->lock, flags);
 136
 137         /* if we have a bulk endpoint, start reading from it */
 138         if (serial->num_bulk_in) {
 139                 /* Start reading from the device */
 140                 usb_fill_bulk_urb(port->read_urb, serial->dev,
 141                                    usb_rcvbulkpipe(serial->dev,
 142                                                 port->bulk_in_endpointAddress),
 143                                    port->read_urb->transfer_buffer,
 144                                    port->read_urb->transfer_buffer_length,
 145                                    ((serial->type->read_bulk_callback) ?
 146                                      serial->type->read_bulk_callback :
 147                                      usb_serial_generic_read_bulk_callback),
 148                                    port);
 149                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 150                 if (result)
 151                         dev_err(&port->dev,
 152                             "%s - failed resubmitting read urb, error %d\n",
 153                                                         __func__, result);
 154         }
 155
 156         return result;
 157 }
 158 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 159
 160 static void generic_cleanup(struct usb_serial_port *port)
 161 {
 162         struct usb_serial *serial = port->serial;
 163
 164         dbg("%s - port %d", __func__, port->number);
 165
 166         if (serial->dev) {
 167                 /* shutdown any bulk reads that might be going on */
 168                 if (serial->num_bulk_out)
 169                         usb_kill_urb(port->write_urb);
 170                 if (serial->num_bulk_in)
 171                         usb_kill_urb(port->read_urb);
 172         }
 173 }
 174
 175 int usb_serial_generic_resume(struct usb_serial *serial)
 176 {
 177         struct usb_serial_port *port;
 178         int i, c = 0, r;
 179
 180 #ifdef CONFIG_PM
 181         /*
 182          * If this is an autoresume, don't submit URBs.
 183          * They will be submitted in the open function instead.
 184          */
 185         if (serial->dev->auto_pm)
 186                 return 0;
 187 #endif
 188         for (i = 0; i < serial->num_ports; i++) {
 189                 port = serial->port[i];
 190                 if (port->port.count && port->read_urb) {
 191                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 192                         if (r < 0)
 193                                 c++;
 194                 }
 195         }
 196
 197         return c ? -EIO : 0;
 198 }
 199
 200 void usb_serial_generic_close(struct tty_struct *tty,
 201                         struct usb_serial_port *port, struct file *filp)
 202 {
 203         dbg("%s - port %d", __func__, port->number);
 204         generic_cleanup(port);
 205 }
 206
 207 int usb_serial_generic_write(struct tty_struct *tty,
 208         struct usb_serial_port *port, const unsigned char *buf, int count)
 209 {
 210         struct usb_serial *serial = port->serial;
 211         int result;
 212         unsigned char *data;
 213
 214         dbg("%s - port %d", __func__, port->number);
 215
 216         if (count == 0) {
 217                 dbg("%s - write request of 0 bytes", __func__);
 218                 return 0;
 219         }
 220
 221         /* only do something if we have a bulk out endpoint */
 222         if (serial->num_bulk_out) {
 223                 unsigned long flags;
 224                 spin_lock_irqsave(&port->lock, flags);
 225                 if (port->write_urb_busy) {
 226                         spin_unlock_irqrestore(&port->lock, flags);
 227                         dbg("%s - already writing", __func__);
 228                         return 0;
 229                 }
 230                 port->write_urb_busy = 1;
 231                 spin_unlock_irqrestore(&port->lock, flags);
 232
 233                 count = (count > port->bulk_out_size) ?
 234                                         port->bulk_out_size : count;
 235
 236                 memcpy(port->write_urb->transfer_buffer, buf, count);
 237                 data = port->write_urb->transfer_buffer;
 238                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 239
 240                 /* set up our urb */
 241                 usb_fill_bulk_urb(port->write_urb, serial->dev,
 242                                    usb_sndbulkpipe(serial->dev,
 243                                         port->bulk_out_endpointAddress),
 244                                    port->write_urb->transfer_buffer, count,
 245                                    ((serial->type->write_bulk_callback) ?
 246                                      serial->type->write_bulk_callback :
 247                                      usb_serial_generic_write_bulk_callback),
 248                                    port);
 249
 250                 /* send the data out the bulk port */
 251                 port->write_urb_busy = 1;
 252                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 253                 if (result) {
 254                         dev_err(&port->dev,
 255                                 "%s - failed submitting write urb, error %d\n",
 256                                                         __func__, result);
 257                         /* don't have to grab the lock here, as we will
 258                            retry if != 0 */
 259                         port->write_urb_busy = 0;
 260                 } else
 261                         result = count;
 262
 263                 return result;
 264         }
 265
 266         /* no bulk out, so return 0 bytes written */
 267         return 0;
 268 }
 269
 270 int usb_serial_generic_write_room(struct tty_struct *tty)
 271 {
 272         struct usb_serial_port *port = tty->driver_data;
 273         struct usb_serial *serial = port->serial;
 274         int room = 0;
 275
 276         dbg("%s - port %d", __func__, port->number);
 277
 278         /* FIXME: Locking */
 279         if (serial->num_bulk_out) {
 280                 if (!(port->write_urb_busy))
 281                         room = port->bulk_out_size;
 282         }
 283
 284         dbg("%s - returns %d", __func__, room);
 285         return room;
 286 }
 287
 288 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 289 {
 290         struct usb_serial_port *port = tty->driver_data;
 291         struct usb_serial *serial = port->serial;
 292         int chars = 0;
 293
 294         dbg("%s - port %d", __func__, port->number);
 295
 296         /* FIXME: Locking */
 297         if (serial->num_bulk_out) {
 298                 if (port->write_urb_busy)
 299                         chars = port->write_urb->transfer_buffer_length;
 300         }
 301
 302         dbg("%s - returns %d", __func__, chars);
 303         return chars;
 304 }
 305
 306
 307 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 308 {
 309         struct urb *urb = port->read_urb;
 310         struct usb_serial *serial = port->serial;
 311         int result;
 312
 313         /* Continue reading from device */
 314         usb_fill_bulk_urb(urb, serial->dev,
 315                            usb_rcvbulkpipe(serial->dev,
 316                                         port->bulk_in_endpointAddress),
 317                            urb->transfer_buffer,
 318                            urb->transfer_buffer_length,
 319                            ((serial->type->read_bulk_callback) ?
 320                              serial->type->read_bulk_callback :
 321                              usb_serial_generic_read_bulk_callback), port);
 322         result = usb_submit_urb(urb, mem_flags);
 323         if (result)
 324                 dev_err(&port->dev,
 325                         "%s - failed resubmitting read urb, error %d\n",
 326                                                         __func__, result);
 327 }
 328
 329 /* Push data to tty layer and resubmit the bulk read URB */
 330 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 331 {
 332         struct urb *urb = port->read_urb;
 333         struct tty_struct *tty = tty_port_tty_get(&port->port);
 334         int room;
 335
 336         /* Push data to tty */
 337         if (tty && urb->actual_length) {
 338                 room = tty_buffer_request_room(tty, urb->actual_length);
 339                 if (room) {
 340                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 341                         tty_flip_buffer_push(tty);
 342                 }
 343         }
 344         tty_kref_put(tty);
 345
 346         resubmit_read_urb(port, GFP_ATOMIC);
 347 }
 348
 349 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 350 {
 351         struct usb_serial_port *port = urb->context;
 352         unsigned char *data = urb->transfer_buffer;
 353         int status = urb->status;
 354         unsigned long flags;
 355
 356         dbg("%s - port %d", __func__, port->number);
 357
 358         if (unlikely(status != 0)) {
 359                 dbg("%s - nonzero read bulk status received: %d",
 360                     __func__, status);
 361                 return;
 362         }
 363
 364         usb_serial_debug_data(debug, &port->dev, __func__,
 365                                                 urb->actual_length, data);
 366
 367         /* Throttle the device if requested by tty */
 368         spin_lock_irqsave(&port->lock, flags);
 369         port->throttled = port->throttle_req;
 370         if (!port->throttled) {
 371                 spin_unlock_irqrestore(&port->lock, flags);
 372                 flush_and_resubmit_read_urb(port);
 373         } else
 374                 spin_unlock_irqrestore(&port->lock, flags);
 375 }
 376 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 377
 378 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 379 {
 380         struct usb_serial_port *port = urb->context;
 381         int status = urb->status;
 382
 383         dbg("%s - port %d", __func__, port->number);
 384
 385         port->write_urb_busy = 0;
 386         if (status) {
 387                 dbg("%s - nonzero write bulk status received: %d",
 388                     __func__, status);
 389                 return;
 390         }
 391         usb_serial_port_softint(port);
 392 }
 393 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 394
 395 void usb_serial_generic_throttle(struct tty_struct *tty)
 396 {
 397         struct usb_serial_port *port = tty->driver_data;
 398         unsigned long flags;
 399
 400         dbg("%s - port %d", __func__, port->number);
 401
 402         /* Set the throttle request flag. It will be picked up
 403          * by usb_serial_generic_read_bulk_callback(). */
 404         spin_lock_irqsave(&port->lock, flags);
 405         port->throttle_req = 1;
 406         spin_unlock_irqrestore(&port->lock, flags);
 407 }
 408
 409 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 410 {
 411         struct usb_serial_port *port = tty->driver_data;
 412         int was_throttled;
 413         unsigned long flags;
 414
 415         dbg("%s - port %d", __func__, port->number);
 416
 417         /* Clear the throttle flags */
 418         spin_lock_irqsave(&port->lock, flags);
 419         was_throttled = port->throttled;
 420         port->throttled = port->throttle_req = 0;
 421         spin_unlock_irqrestore(&port->lock, flags);
 422
 423         if (was_throttled) {
 424                 /* Resume reading from device */
 425                 resubmit_read_urb(port, GFP_KERNEL);
 426         }
 427 }
 428
 429 void usb_serial_generic_shutdown(struct usb_serial *serial)
 430 {
 431         int i;
 432
 433         dbg("%s", __func__);
 434
 435         /* stop reads and writes on all ports */
 436         for (i = 0; i < serial->num_ports; ++i)
 437                 generic_cleanup(serial->port[i]);
 438 }
 439