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         .disconnect =           usb_serial_generic_disconnect,
  67         .release =              usb_serial_generic_release,
  68         .throttle =             usb_serial_generic_throttle,
  69         .unthrottle =           usb_serial_generic_unthrottle,
  70         .resume =               usb_serial_generic_resume,
  71 };
  72
  73 static int generic_probe(struct usb_interface *interface,
  74                                const struct usb_device_id *id)
  75 {
  76         const struct usb_device_id *id_pattern;
  77
  78         id_pattern = usb_match_id(interface, generic_device_ids);
  79         if (id_pattern != NULL)
  80                 return usb_serial_probe(interface, id);
  81         return -ENODEV;
  82 }
  83 #endif
  84
  85 int usb_serial_generic_register(int _debug)
  86 {
  87         int retval = 0;
  88
  89         debug = _debug;
  90 #ifdef CONFIG_USB_SERIAL_GENERIC
  91         generic_device_ids[0].idVendor = vendor;
  92         generic_device_ids[0].idProduct = product;
  93         generic_device_ids[0].match_flags =
  94                 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  95
  96         /* register our generic driver with ourselves */
  97         retval = usb_serial_register(&usb_serial_generic_device);
  98         if (retval)
  99                 goto exit;
 100         retval = usb_register(&generic_driver);
 101         if (retval)
 102                 usb_serial_deregister(&usb_serial_generic_device);
 103 exit:
 104 #endif
 105         return retval;
 106 }
 107
 108 void usb_serial_generic_deregister(void)
 109 {
 110 #ifdef CONFIG_USB_SERIAL_GENERIC
 111         /* remove our generic driver */
 112         usb_deregister(&generic_driver);
 113         usb_serial_deregister(&usb_serial_generic_device);
 114 #endif
 115 }
 116
 117 int usb_serial_generic_open(struct tty_struct *tty,
 118                         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", __func__, port->number);
 125
 126         /* clear the throttle flags */
 127         spin_lock_irqsave(&port->lock, flags);
 128         port->throttled = 0;
 129         port->throttle_req = 0;
 130         spin_unlock_irqrestore(&port->lock, flags);
 131
 132         /* if we have a bulk endpoint, start reading from it */
 133         if (serial->num_bulk_in) {
 134                 /* Start reading from the device */
 135                 usb_fill_bulk_urb(port->read_urb, serial->dev,
 136                                    usb_rcvbulkpipe(serial->dev,
 137                                                 port->bulk_in_endpointAddress),
 138                                    port->read_urb->transfer_buffer,
 139                                    port->read_urb->transfer_buffer_length,
 140                                    ((serial->type->read_bulk_callback) ?
 141                                      serial->type->read_bulk_callback :
 142                                      usb_serial_generic_read_bulk_callback),
 143                                    port);
 144                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 145                 if (result)
 146                         dev_err(&port->dev,
 147                             "%s - failed resubmitting read urb, error %d\n",
 148                                                         __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->port.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 tty_struct *tty,
 196                         struct usb_serial_port *port, struct file *filp)
 197 {
 198         dbg("%s - port %d", __func__, port->number);
 199         generic_cleanup(port);
 200 }
 201
 202 int usb_serial_generic_write(struct tty_struct *tty,
 203         struct usb_serial_port *port, const unsigned char *buf, int count)
 204 {
 205         struct usb_serial *serial = port->serial;
 206         int result;
 207         unsigned char *data;
 208
 209         dbg("%s - port %d", __func__, port->number);
 210
 211         if (count == 0) {
 212                 dbg("%s - write request of 0 bytes", __func__);
 213                 return 0;
 214         }
 215
 216         /* only do something if we have a bulk out endpoint */
 217         if (serial->num_bulk_out) {
 218                 unsigned long flags;
 219                 spin_lock_irqsave(&port->lock, flags);
 220                 if (port->write_urb_busy) {
 221                         spin_unlock_irqrestore(&port->lock, flags);
 222                         dbg("%s - already writing", __func__);
 223                         return 0;
 224                 }
 225                 port->write_urb_busy = 1;
 226                 spin_unlock_irqrestore(&port->lock, flags);
 227
 228                 count = (count > port->bulk_out_size) ?
 229                                         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, __func__, 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),
 243                                    port);
 244
 245                 /* send the data out the bulk port */
 246                 port->write_urb_busy = 1;
 247                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 248                 if (result) {
 249                         dev_err(&port->dev,
 250                                 "%s - failed submitting write urb, error %d\n",
 251                                                         __func__, result);
 252                         /* don't have to grab the lock here, as we will
 253                            retry if != 0 */
 254                         port->write_urb_busy = 0;
 255                 } else
 256                         result = count;
 257
 258                 return result;
 259         }
 260
 261         /* no bulk out, so return 0 bytes written */
 262         return 0;
 263 }
 264
 265 int usb_serial_generic_write_room(struct tty_struct *tty)
 266 {
 267         struct usb_serial_port *port = tty->driver_data;
 268         struct usb_serial *serial = port->serial;
 269         int room = 0;
 270
 271         dbg("%s - port %d", __func__, port->number);
 272
 273         /* FIXME: Locking */
 274         if (serial->num_bulk_out) {
 275                 if (!(port->write_urb_busy))
 276                         room = port->bulk_out_size;
 277         }
 278
 279         dbg("%s - returns %d", __func__, room);
 280         return room;
 281 }
 282
 283 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 284 {
 285         struct usb_serial_port *port = tty->driver_data;
 286         struct usb_serial *serial = port->serial;
 287         int chars = 0;
 288
 289         dbg("%s - port %d", __func__, port->number);
 290
 291         /* FIXME: Locking */
 292         if (serial->num_bulk_out) {
 293                 if (port->write_urb_busy)
 294                         chars = port->write_urb->transfer_buffer_length;
 295         }
 296
 297         dbg("%s - returns %d", __func__, chars);
 298         return chars;
 299 }
 300
 301
 302 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 303 {
 304         struct urb *urb = port->read_urb;
 305         struct usb_serial *serial = port->serial;
 306         int result;
 307
 308         /* Continue reading from device */
 309         usb_fill_bulk_urb(urb, serial->dev,
 310                            usb_rcvbulkpipe(serial->dev,
 311                                         port->bulk_in_endpointAddress),
 312                            urb->transfer_buffer,
 313                            urb->transfer_buffer_length,
 314                            ((serial->type->read_bulk_callback) ?
 315                              serial->type->read_bulk_callback :
 316                              usb_serial_generic_read_bulk_callback), port);
 317         result = usb_submit_urb(urb, mem_flags);
 318         if (result)
 319                 dev_err(&port->dev,
 320                         "%s - failed resubmitting read urb, error %d\n",
 321                                                         __func__, result);
 322 }
 323
 324 /* Push data to tty layer and resubmit the bulk read URB */
 325 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 326 {
 327         struct urb *urb = port->read_urb;
 328         struct tty_struct *tty = port->port.tty;
 329         int room;
 330
 331         /* Push data to tty */
 332         if (tty && urb->actual_length) {
 333                 room = tty_buffer_request_room(tty, urb->actual_length);
 334                 if (room) {
 335                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 336                         tty_flip_buffer_push(tty);
 337                 }
 338         }
 339
 340         resubmit_read_urb(port, GFP_ATOMIC);
 341 }
 342
 343 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 344 {
 345         struct usb_serial_port *port = urb->context;
 346         unsigned char *data = urb->transfer_buffer;
 347         int status = urb->status;
 348         unsigned long flags;
 349
 350         dbg("%s - port %d", __func__, port->number);
 351
 352         if (unlikely(status != 0)) {
 353                 dbg("%s - nonzero read bulk status received: %d",
 354                     __func__, status);
 355                 return;
 356         }
 357
 358         usb_serial_debug_data(debug, &port->dev, __func__,
 359                                                 urb->actual_length, data);
 360
 361         /* Throttle the device if requested by tty */
 362         spin_lock_irqsave(&port->lock, flags);
 363         port->throttled = port->throttle_req;
 364         if (!port->throttled) {
 365                 spin_unlock_irqrestore(&port->lock, flags);
 366                 flush_and_resubmit_read_urb(port);
 367         } else
 368                 spin_unlock_irqrestore(&port->lock, flags);
 369 }
 370 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 371
 372 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 373 {
 374         struct usb_serial_port *port = urb->context;
 375         int status = urb->status;
 376
 377         dbg("%s - port %d", __func__, port->number);
 378
 379         port->write_urb_busy = 0;
 380         if (status) {
 381                 dbg("%s - nonzero write bulk status received: %d",
 382                     __func__, status);
 383                 return;
 384         }
 385         usb_serial_port_softint(port);
 386 }
 387 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 388
 389 void usb_serial_generic_throttle(struct tty_struct *tty)
 390 {
 391         struct usb_serial_port *port = tty->driver_data;
 392         unsigned long flags;
 393
 394         dbg("%s - port %d", __func__, port->number);
 395
 396         /* Set the throttle request flag. It will be picked up
 397          * by usb_serial_generic_read_bulk_callback(). */
 398         spin_lock_irqsave(&port->lock, flags);
 399         port->throttle_req = 1;
 400         spin_unlock_irqrestore(&port->lock, flags);
 401 }
 402
 403 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 404 {
 405         struct usb_serial_port *port = tty->driver_data;
 406         int was_throttled;
 407         unsigned long flags;
 408
 409         dbg("%s - port %d", __func__, port->number);
 410
 411         /* Clear the throttle flags */
 412         spin_lock_irqsave(&port->lock, flags);
 413         was_throttled = port->throttled;
 414         port->throttled = port->throttle_req = 0;
 415         spin_unlock_irqrestore(&port->lock, flags);
 416
 417         if (was_throttled) {
 418                 /* Resume reading from device */
 419                 resubmit_read_urb(port, GFP_KERNEL);
 420         }
 421 }
 422
 423 void usb_serial_generic_disconnect(struct usb_serial *serial)
 424 {
 425         int i;
 426
 427         dbg("%s", __func__);
 428
 429         /* stop reads and writes on all ports */
 430         for (i = 0; i < serial->num_ports; ++i)
 431                 generic_cleanup(serial->port[i]);
 432 }
 433
 434 void usb_serial_generic_release(struct usb_serial *serial)
 435 {
 436         dbg("%s", __func__);
 437 }