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 tty_struct *tty,
 188                         struct usb_serial_port *port, struct file *filp)
 189 {
 190         dbg("%s - port %d", __func__, port->number);
 191         generic_cleanup(port);
 192 }
 193
 194 int usb_serial_generic_write(struct tty_struct *tty,
 195         struct usb_serial_port *port, const unsigned char *buf, int count)
 196 {
 197         struct usb_serial *serial = port->serial;
 198         int result;
 199         unsigned char *data;
 200
 201         dbg("%s - port %d", __func__, port->number);
 202
 203         if (count == 0) {
 204                 dbg("%s - write request of 0 bytes", __func__);
 205                 return 0;
 206         }
 207
 208         /* only do something if we have a bulk out endpoint */
 209         if (serial->num_bulk_out) {
 210                 unsigned long flags;
 211                 spin_lock_irqsave(&port->lock, flags);
 212                 if (port->write_urb_busy) {
 213                         spin_unlock_irqrestore(&port->lock, flags);
 214                         dbg("%s - already writing", __func__);
 215                         return 0;
 216                 }
 217                 port->write_urb_busy = 1;
 218                 spin_unlock_irqrestore(&port->lock, flags);
 219
 220                 count = (count > port->bulk_out_size) ?
 221                                         port->bulk_out_size : count;
 222
 223                 memcpy(port->write_urb->transfer_buffer, buf, count);
 224                 data = port->write_urb->transfer_buffer;
 225                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 226
 227                 /* set up our urb */
 228                 usb_fill_bulk_urb(port->write_urb, serial->dev,
 229                                    usb_sndbulkpipe(serial->dev,
 230                                         port->bulk_out_endpointAddress),
 231                                    port->write_urb->transfer_buffer, count,
 232                                    ((serial->type->write_bulk_callback) ?
 233                                      serial->type->write_bulk_callback :
 234                                      usb_serial_generic_write_bulk_callback),
 235                                    port);
 236
 237                 /* send the data out the bulk port */
 238                 port->write_urb_busy = 1;
 239                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 240                 if (result) {
 241                         dev_err(&port->dev,
 242                                 "%s - failed submitting write urb, error %d\n",
 243                                                         __func__, result);
 244                         /* don't have to grab the lock here, as we will
 245                            retry if != 0 */
 246                         port->write_urb_busy = 0;
 247                 } else
 248                         result = count;
 249
 250                 return result;
 251         }
 252
 253         /* no bulk out, so return 0 bytes written */
 254         return 0;
 255 }
 256
 257 int usb_serial_generic_write_room(struct tty_struct *tty)
 258 {
 259         struct usb_serial_port *port = tty->driver_data;
 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 tty_struct *tty)
 276 {
 277         struct usb_serial_port *port = tty->driver_data;
 278         struct usb_serial *serial = port->serial;
 279         int chars = 0;
 280
 281         dbg("%s - port %d", __func__, port->number);
 282
 283         /* FIXME: Locking */
 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", __func__, 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,
 312                         "%s - failed resubmitting read urb, error %d\n",
 313                                                         __func__, result);
 314 }
 315
 316 /* Push data to tty layer and resubmit the bulk read URB */
 317 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 318 {
 319         struct urb *urb = port->read_urb;
 320         struct tty_struct *tty = tty_port_tty_get(&port->port);
 321         int room;
 322
 323         /* Push data to tty */
 324         if (tty && urb->actual_length) {
 325                 room = tty_buffer_request_room(tty, urb->actual_length);
 326                 if (room) {
 327                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 328                         tty_flip_buffer_push(tty);
 329                 }
 330         }
 331         tty_kref_put(tty);
 332
 333         resubmit_read_urb(port, GFP_ATOMIC);
 334 }
 335
 336 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 337 {
 338         struct usb_serial_port *port = urb->context;
 339         unsigned char *data = urb->transfer_buffer;
 340         int status = urb->status;
 341         unsigned long flags;
 342
 343         dbg("%s - port %d", __func__, port->number);
 344
 345         if (unlikely(status != 0)) {
 346                 dbg("%s - nonzero read bulk status received: %d",
 347                     __func__, status);
 348                 return;
 349         }
 350
 351         usb_serial_debug_data(debug, &port->dev, __func__,
 352                                                 urb->actual_length, data);
 353
 354         /* Throttle the device if requested by tty */
 355         spin_lock_irqsave(&port->lock, flags);
 356         port->throttled = port->throttle_req;
 357         if (!port->throttled) {
 358                 spin_unlock_irqrestore(&port->lock, flags);
 359                 flush_and_resubmit_read_urb(port);
 360         } else
 361                 spin_unlock_irqrestore(&port->lock, flags);
 362 }
 363 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 364
 365 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 366 {
 367         struct usb_serial_port *port = urb->context;
 368         int status = urb->status;
 369
 370         dbg("%s - port %d", __func__, port->number);
 371
 372         port->write_urb_busy = 0;
 373         if (status) {
 374                 dbg("%s - nonzero write bulk status received: %d",
 375                     __func__, status);
 376                 return;
 377         }
 378         usb_serial_port_softint(port);
 379 }
 380 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 381
 382 void usb_serial_generic_throttle(struct tty_struct *tty)
 383 {
 384         struct usb_serial_port *port = tty->driver_data;
 385         unsigned long flags;
 386
 387         dbg("%s - port %d", __func__, port->number);
 388
 389         /* Set the throttle request flag. It will be picked up
 390          * by usb_serial_generic_read_bulk_callback(). */
 391         spin_lock_irqsave(&port->lock, flags);
 392         port->throttle_req = 1;
 393         spin_unlock_irqrestore(&port->lock, flags);
 394 }
 395
 396 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 397 {
 398         struct usb_serial_port *port = tty->driver_data;
 399         int was_throttled;
 400         unsigned long flags;
 401
 402         dbg("%s - port %d", __func__, port->number);
 403
 404         /* Clear the throttle flags */
 405         spin_lock_irqsave(&port->lock, flags);
 406         was_throttled = port->throttled;
 407         port->throttled = port->throttle_req = 0;
 408         spin_unlock_irqrestore(&port->lock, flags);
 409
 410         if (was_throttled) {
 411                 /* Resume reading from device */
 412                 resubmit_read_urb(port, GFP_KERNEL);
 413         }
 414 }
 415
 416 void usb_serial_generic_shutdown(struct usb_serial *serial)
 417 {
 418         int i;
 419
 420         dbg("%s", __func__);
 421
 422         /* stop reads and writes on all ports */
 423         for (i = 0; i < serial->num_ports; ++i)
 424                 generic_cleanup(serial->port[i]);
 425 }
 426