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 <asm/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 = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  93
  94         /* register our generic driver with ourselves */
  95         retval = usb_serial_register (&usb_serial_generic_device);
  96         if (retval)
  97                 goto exit;
  98         retval = usb_register(&generic_driver);
  99         if (retval)
 100                 usb_serial_deregister(&usb_serial_generic_device);
 101 exit:
 102 #endif
 103         return retval;
 104 }
 105
 106 void usb_serial_generic_deregister (void)
 107 {
 108 #ifdef CONFIG_USB_SERIAL_GENERIC
 109         /* remove our generic driver */
 110         usb_deregister(&generic_driver);
 111         usb_serial_deregister (&usb_serial_generic_device);
 112 #endif
 113 }
 114
 115 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
 116 {
 117         struct usb_serial *serial = port->serial;
 118         int result = 0;
 119         unsigned long flags;
 120
 121         dbg("%s - port %d", __func__, port->number);
 122
 123         /* force low_latency on so that our tty_push actually forces the data through,
 124            otherwise it is scheduled, and with high data rates (like with OHCI) data
 125            can get lost. */
 126         if (port->tty)
 127                 port->tty->low_latency = 1;
 128
 129         /* clear the throttle flags */
 130         spin_lock_irqsave(&port->lock, flags);
 131         port->throttled = 0;
 132         port->throttle_req = 0;
 133         spin_unlock_irqrestore(&port->lock, flags);
 134
 135         /* if we have a bulk endpoint, start reading from it */
 136         if (serial->num_bulk_in) {
 137                 /* Start reading from the device */
 138                 usb_fill_bulk_urb (port->read_urb, serial->dev,
 139                                    usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
 140                                    port->read_urb->transfer_buffer,
 141                                    port->read_urb->transfer_buffer_length,
 142                                    ((serial->type->read_bulk_callback) ?
 143                                      serial->type->read_bulk_callback :
 144                                      usb_serial_generic_read_bulk_callback),
 145                                    port);
 146                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 147                 if (result)
 148                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __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 #ifdef CONFIG_PM
 176         /*
 177          * If this is an autoresume, don't submit URBs.
 178          * They will be submitted in the open function instead.
 179          */
 180         if (serial->dev->auto_pm)
 181                 return 0;
 182 #endif
 183         for (i = 0; i < serial->num_ports; i++) {
 184                 port = serial->port[i];
 185                 if (port->open_count && port->read_urb) {
 186                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 187                         if (r < 0)
 188                                 c++;
 189                 }
 190         }
 191
 192         return c ? -EIO : 0;
 193 }
 194
 195 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 196 {
 197         dbg("%s - port %d", __func__, port->number);
 198         generic_cleanup (port);
 199 }
 200
 201 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 202 {
 203         struct usb_serial *serial = port->serial;
 204         int result;
 205         unsigned char *data;
 206
 207         dbg("%s - port %d", __func__, port->number);
 208
 209         if (count == 0) {
 210                 dbg("%s - write request of 0 bytes", __func__);
 211                 return (0);
 212         }
 213
 214         /* only do something if we have a bulk out endpoint */
 215         if (serial->num_bulk_out) {
 216                 unsigned long flags;
 217                 spin_lock_irqsave(&port->lock, flags);
 218                 if (port->write_urb_busy) {
 219                         spin_unlock_irqrestore(&port->lock, flags);
 220                         dbg("%s - already writing", __func__);
 221                         return 0;
 222                 }
 223                 port->write_urb_busy = 1;
 224                 spin_unlock_irqrestore(&port->lock, flags);
 225
 226                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 227
 228                 memcpy (port->write_urb->transfer_buffer, buf, count);
 229                 data = port->write_urb->transfer_buffer;
 230                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 231
 232                 /* set up our urb */
 233                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 234                                    usb_sndbulkpipe (serial->dev,
 235                                                     port->bulk_out_endpointAddress),
 236                                    port->write_urb->transfer_buffer, count,
 237                                    ((serial->type->write_bulk_callback) ?
 238                                      serial->type->write_bulk_callback :
 239                                      usb_serial_generic_write_bulk_callback), port);
 240
 241                 /* send the data out the bulk port */
 242                 port->write_urb_busy = 1;
 243                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 244                 if (result) {
 245                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __func__, result);
 246                         /* don't have to grab the lock here, as we will retry if != 0 */
 247                         port->write_urb_busy = 0;
 248                 } else
 249                         result = count;
 250
 251                 return result;
 252         }
 253
 254         /* no bulk out, so return 0 bytes written */
 255         return 0;
 256 }
 257
 258 int usb_serial_generic_write_room (struct usb_serial_port *port)
 259 {
 260         struct usb_serial *serial = port->serial;
 261         int room = 0;
 262
 263         dbg("%s - port %d", __func__, port->number);
 264
 265         /* FIXME: Locking */
 266         if (serial->num_bulk_out) {
 267                 if (!(port->write_urb_busy))
 268                         room = port->bulk_out_size;
 269         }
 270
 271         dbg("%s - returns %d", __func__, room);
 272         return room;
 273 }
 274
 275 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 276 {
 277         struct usb_serial *serial = port->serial;
 278         int chars = 0;
 279
 280         dbg("%s - port %d", __func__, port->number);
 281
 282         /* FIXME: Locking */
 283         if (serial->num_bulk_out) {
 284                 if (port->write_urb_busy)
 285                         chars = port->write_urb->transfer_buffer_length;
 286         }
 287
 288         dbg("%s - returns %d", __func__, chars);
 289         return (chars);
 290 }
 291
 292
 293 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 294 {
 295         struct urb *urb = port->read_urb;
 296         struct usb_serial *serial = port->serial;
 297         int result;
 298
 299         /* Continue reading from device */
 300         usb_fill_bulk_urb (urb, serial->dev,
 301                            usb_rcvbulkpipe (serial->dev,
 302                                             port->bulk_in_endpointAddress),
 303                            urb->transfer_buffer,
 304                            urb->transfer_buffer_length,
 305                            ((serial->type->read_bulk_callback) ?
 306                              serial->type->read_bulk_callback :
 307                              usb_serial_generic_read_bulk_callback), port);
 308         result = usb_submit_urb(urb, mem_flags);
 309         if (result)
 310                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __func__, result);
 311 }
 312
 313 /* Push data to tty layer and resubmit the bulk read URB */
 314 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
 315 {
 316         struct urb *urb = port->read_urb;
 317         struct tty_struct *tty = port->tty;
 318         int room;
 319
 320         /* Push data to tty */
 321         if (tty && urb->actual_length) {
 322                 room = tty_buffer_request_room(tty, urb->actual_length);
 323                 if (room) {
 324                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 325                         tty_flip_buffer_push(tty);
 326                 }
 327         }
 328
 329         resubmit_read_urb(port, GFP_ATOMIC);
 330 }
 331
 332 void usb_serial_generic_read_bulk_callback (struct urb *urb)
 333 {
 334         struct usb_serial_port *port = urb->context;
 335         unsigned char *data = urb->transfer_buffer;
 336         int status = urb->status;
 337         unsigned long flags;
 338
 339         dbg("%s - port %d", __func__, port->number);
 340
 341         if (unlikely(status != 0)) {
 342                 dbg("%s - nonzero read bulk status received: %d",
 343                     __func__, status);
 344                 return;
 345         }
 346
 347         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, data);
 348
 349         /* Throttle the device if requested by tty */
 350         spin_lock_irqsave(&port->lock, flags);
 351         if (!(port->throttled = port->throttle_req)) {
 352                 spin_unlock_irqrestore(&port->lock, flags);
 353                 flush_and_resubmit_read_urb(port);
 354         } else {
 355                 spin_unlock_irqrestore(&port->lock, flags);
 356         }
 357 }
 358 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 359
 360 void usb_serial_generic_write_bulk_callback (struct urb *urb)
 361 {
 362         struct usb_serial_port *port = urb->context;
 363         int status = urb->status;
 364
 365         dbg("%s - port %d", __func__, port->number);
 366
 367         port->write_urb_busy = 0;
 368         if (status) {
 369                 dbg("%s - nonzero write bulk status received: %d",
 370                     __func__, status);
 371                 return;
 372         }
 373         usb_serial_port_softint(port);
 374 }
 375 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 376
 377 void usb_serial_generic_throttle (struct usb_serial_port *port)
 378 {
 379         unsigned long flags;
 380
 381         dbg("%s - port %d", __func__, port->number);
 382
 383         /* Set the throttle request flag. It will be picked up
 384          * by usb_serial_generic_read_bulk_callback(). */
 385         spin_lock_irqsave(&port->lock, flags);
 386         port->throttle_req = 1;
 387         spin_unlock_irqrestore(&port->lock, flags);
 388 }
 389
 390 void usb_serial_generic_unthrottle (struct usb_serial_port *port)
 391 {
 392         int was_throttled;
 393         unsigned long flags;
 394
 395         dbg("%s - port %d", __func__, port->number);
 396
 397         /* Clear the throttle flags */
 398         spin_lock_irqsave(&port->lock, flags);
 399         was_throttled = port->throttled;
 400         port->throttled = port->throttle_req = 0;
 401         spin_unlock_irqrestore(&port->lock, flags);
 402
 403         if (was_throttled) {
 404                 /* Resume reading from device */
 405                 resubmit_read_urb(port, GFP_KERNEL);
 406         }
 407 }
 408
 409 void usb_serial_generic_shutdown (struct usb_serial *serial)
 410 {
 411         int i;
 412
 413         dbg("%s", __func__);
 414
 415         /* stop reads and writes on all ports */
 416         for (i=0; i < serial->num_ports; ++i) {
 417                 generic_cleanup(serial->port[i]);
 418         }
 419 }
 420