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_interrupt_in =     NUM_DONT_CARE,
  66         .num_bulk_in =          NUM_DONT_CARE,
  67         .num_bulk_out =         NUM_DONT_CARE,
  68         .num_ports =            1,
  69         .shutdown =             usb_serial_generic_shutdown,
  70         .throttle =             usb_serial_generic_throttle,
  71         .unthrottle =           usb_serial_generic_unthrottle,
  72         .resume =               usb_serial_generic_resume,
  73 };
  74
  75 static int generic_probe(struct usb_interface *interface,
  76                                const struct usb_device_id *id)
  77 {
  78         const struct usb_device_id *id_pattern;
  79
  80         id_pattern = usb_match_id(interface, generic_device_ids);
  81         if (id_pattern != NULL)
  82                 return usb_serial_probe(interface, id);
  83         return -ENODEV;
  84 }
  85 #endif
  86
  87 int usb_serial_generic_register (int _debug)
  88 {
  89         int retval = 0;
  90
  91         debug = _debug;
  92 #ifdef CONFIG_USB_SERIAL_GENERIC
  93         generic_device_ids[0].idVendor = vendor;
  94         generic_device_ids[0].idProduct = product;
  95         generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  96
  97         /* register our generic driver with ourselves */
  98         retval = usb_serial_register (&usb_serial_generic_device);
  99         if (retval)
 100                 goto exit;
 101         retval = usb_register(&generic_driver);
 102         if (retval)
 103                 usb_serial_deregister(&usb_serial_generic_device);
 104 exit:
 105 #endif
 106         return retval;
 107 }
 108
 109 void usb_serial_generic_deregister (void)
 110 {
 111 #ifdef CONFIG_USB_SERIAL_GENERIC
 112         /* remove our generic driver */
 113         usb_deregister(&generic_driver);
 114         usb_serial_deregister (&usb_serial_generic_device);
 115 #endif
 116 }
 117
 118 int usb_serial_generic_open (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", __FUNCTION__, port->number);
 125
 126         /* force low_latency on so that our tty_push actually forces the data through,
 127            otherwise it is scheduled, and with high data rates (like with OHCI) data
 128            can get lost. */
 129         if (port->tty)
 130                 port->tty->low_latency = 1;
 131
 132         /* clear the throttle flags */
 133         spin_lock_irqsave(&port->lock, flags);
 134         port->throttled = 0;
 135         port->throttle_req = 0;
 136         spin_unlock_irqrestore(&port->lock, flags);
 137
 138         /* if we have a bulk endpoint, start reading from it */
 139         if (serial->num_bulk_in) {
 140                 /* Start reading from the device */
 141                 usb_fill_bulk_urb (port->read_urb, serial->dev,
 142                                    usb_rcvbulkpipe(serial->dev, 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, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 152         }
 153
 154         return result;
 155 }
 156 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 157
 158 static void generic_cleanup (struct usb_serial_port *port)
 159 {
 160         struct usb_serial *serial = port->serial;
 161
 162         dbg("%s - port %d", __FUNCTION__, port->number);
 163
 164         if (serial->dev) {
 165                 /* shutdown any bulk reads that might be going on */
 166                 if (serial->num_bulk_out)
 167                         usb_kill_urb(port->write_urb);
 168                 if (serial->num_bulk_in)
 169                         usb_kill_urb(port->read_urb);
 170         }
 171 }
 172
 173 int usb_serial_generic_resume(struct usb_serial *serial)
 174 {
 175         struct usb_serial_port *port;
 176         int i, c = 0, r;
 177
 178 #ifdef CONFIG_PM
 179         /*
 180          * If this is an autoresume, don't submit URBs.
 181          * They will be submitted in the open function instead.
 182          */
 183         if (serial->dev->auto_pm)
 184                 return 0;
 185 #endif
 186         for (i = 0; i < serial->num_ports; i++) {
 187                 port = serial->port[i];
 188                 if (port->open_count && port->read_urb) {
 189                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 190                         if (r < 0)
 191                                 c++;
 192                 }
 193         }
 194
 195         return c ? -EIO : 0;
 196 }
 197
 198 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 199 {
 200         dbg("%s - port %d", __FUNCTION__, port->number);
 201         generic_cleanup (port);
 202 }
 203
 204 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 205 {
 206         struct usb_serial *serial = port->serial;
 207         int result;
 208         unsigned char *data;
 209
 210         dbg("%s - port %d", __FUNCTION__, port->number);
 211
 212         if (count == 0) {
 213                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 214                 return (0);
 215         }
 216
 217         /* only do something if we have a bulk out endpoint */
 218         if (serial->num_bulk_out) {
 219                 unsigned long flags;
 220                 spin_lock_irqsave(&port->lock, flags);
 221                 if (port->write_urb_busy) {
 222                         spin_unlock_irqrestore(&port->lock, flags);
 223                         dbg("%s - already writing", __FUNCTION__);
 224                         return 0;
 225                 }
 226                 port->write_urb_busy = 1;
 227                 spin_unlock_irqrestore(&port->lock, flags);
 228
 229                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 230
 231                 memcpy (port->write_urb->transfer_buffer, buf, count);
 232                 data = port->write_urb->transfer_buffer;
 233                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
 234
 235                 /* set up our urb */
 236                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 237                                    usb_sndbulkpipe (serial->dev,
 238                                                     port->bulk_out_endpointAddress),
 239                                    port->write_urb->transfer_buffer, count,
 240                                    ((serial->type->write_bulk_callback) ?
 241                                      serial->type->write_bulk_callback :
 242                                      usb_serial_generic_write_bulk_callback), port);
 243
 244                 /* send the data out the bulk port */
 245                 port->write_urb_busy = 1;
 246                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 247                 if (result) {
 248                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 249                         /* don't have to grab the lock here, as we will retry if != 0 */
 250                         port->write_urb_busy = 0;
 251                 } else
 252                         result = count;
 253
 254                 return result;
 255         }
 256
 257         /* no bulk out, so return 0 bytes written */
 258         return 0;
 259 }
 260
 261 int usb_serial_generic_write_room (struct usb_serial_port *port)
 262 {
 263         struct usb_serial *serial = port->serial;
 264         int room = 0;
 265
 266         dbg("%s - port %d", __FUNCTION__, port->number);
 267
 268         if (serial->num_bulk_out) {
 269                 if (!(port->write_urb_busy))
 270                         room = port->bulk_out_size;
 271         }
 272
 273         dbg("%s - returns %d", __FUNCTION__, room);
 274         return (room);
 275 }
 276
 277 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 278 {
 279         struct usb_serial *serial = port->serial;
 280         int chars = 0;
 281
 282         dbg("%s - port %d", __FUNCTION__, port->number);
 283
 284         if (serial->num_bulk_out) {
 285                 if (port->write_urb_busy)
 286                         chars = port->write_urb->transfer_buffer_length;
 287         }
 288
 289         dbg("%s - returns %d", __FUNCTION__, chars);
 290         return (chars);
 291 }
 292
 293
 294 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 295 {
 296         struct urb *urb = port->read_urb;
 297         struct usb_serial *serial = port->serial;
 298         int result;
 299
 300         /* Continue reading from device */
 301         usb_fill_bulk_urb (urb, serial->dev,
 302                            usb_rcvbulkpipe (serial->dev,
 303                                             port->bulk_in_endpointAddress),
 304                            urb->transfer_buffer,
 305                            urb->transfer_buffer_length,
 306                            ((serial->type->read_bulk_callback) ?
 307                              serial->type->read_bulk_callback :
 308                              usb_serial_generic_read_bulk_callback), port);
 309         result = usb_submit_urb(urb, mem_flags);
 310         if (result)
 311                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 312 }
 313
 314 /* Push data to tty layer and resubmit the bulk read URB */
 315 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
 316 {
 317         struct urb *urb = port->read_urb;
 318         struct tty_struct *tty = port->tty;
 319         int room;
 320
 321         /* Push data to tty */
 322         if (tty && urb->actual_length) {
 323                 room = tty_buffer_request_room(tty, urb->actual_length);
 324                 if (room) {
 325                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 326                         tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
 327                 }
 328         }
 329
 330         resubmit_read_urb(port, GFP_ATOMIC);
 331 }
 332
 333 void usb_serial_generic_read_bulk_callback (struct urb *urb)
 334 {
 335         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 336         unsigned char *data = urb->transfer_buffer;
 337         int status = urb->status;
 338         unsigned long flags;
 339
 340         dbg("%s - port %d", __FUNCTION__, port->number);
 341
 342         if (unlikely(status != 0)) {
 343                 dbg("%s - nonzero read bulk status received: %d",
 344                     __FUNCTION__, status);
 345                 return;
 346         }
 347
 348         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 349
 350         /* Throttle the device if requested by tty */
 351         spin_lock_irqsave(&port->lock, flags);
 352         if (!(port->throttled = port->throttle_req))
 353                 /* Handle data and continue reading from device */
 354                 flush_and_resubmit_read_urb(port);
 355         spin_unlock_irqrestore(&port->lock, flags);
 356 }
 357 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 358
 359 void usb_serial_generic_write_bulk_callback (struct urb *urb)
 360 {
 361         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 362         int status = urb->status;
 363
 364         dbg("%s - port %d", __FUNCTION__, port->number);
 365
 366         port->write_urb_busy = 0;
 367         if (status) {
 368                 dbg("%s - nonzero write bulk status received: %d",
 369                     __FUNCTION__, status);
 370                 return;
 371         }
 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", __FUNCTION__, 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", __FUNCTION__, 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", __FUNCTION__);
 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