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         for (i = 0; i < serial->num_ports; i++) {
 181                 port = serial->port[i];
 182                 if (port->port.count && port->read_urb) {
 183                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 184                         if (r < 0)
 185                                 c++;
 186                 }
 187         }
 188
 189         return c ? -EIO : 0;
 190 }
 191 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
 192
 193 void usb_serial_generic_close(struct tty_struct *tty,
 194                         struct usb_serial_port *port, struct file *filp)
 195 {
 196         dbg("%s - port %d", __func__, port->number);
 197         generic_cleanup(port);
 198 }
 199
 200 int usb_serial_generic_write(struct tty_struct *tty,
 201         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) ?
 227                                         port->bulk_out_size : count;
 228
 229                 memcpy(port->write_urb->transfer_buffer, buf, count);
 230                 data = port->write_urb->transfer_buffer;
 231                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 232
 233                 /* set up our urb */
 234                 usb_fill_bulk_urb(port->write_urb, serial->dev,
 235                                    usb_sndbulkpipe(serial->dev,
 236                                         port->bulk_out_endpointAddress),
 237                                    port->write_urb->transfer_buffer, count,
 238                                    ((serial->type->write_bulk_callback) ?
 239                                      serial->type->write_bulk_callback :
 240                                      usb_serial_generic_write_bulk_callback),
 241                                    port);
 242
 243                 /* send the data out the bulk port */
 244                 port->write_urb_busy = 1;
 245                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 246                 if (result) {
 247                         dev_err(&port->dev,
 248                                 "%s - failed submitting write urb, error %d\n",
 249                                                         __func__, result);
 250                         /* don't have to grab the lock here, as we will
 251                            retry if != 0 */
 252                         port->write_urb_busy = 0;
 253                 } else
 254                         result = count;
 255
 256                 return result;
 257         }
 258
 259         /* no bulk out, so return 0 bytes written */
 260         return 0;
 261 }
 262
 263 int usb_serial_generic_write_room(struct tty_struct *tty)
 264 {
 265         struct usb_serial_port *port = tty->driver_data;
 266         struct usb_serial *serial = port->serial;
 267         int room = 0;
 268
 269         dbg("%s - port %d", __func__, port->number);
 270
 271         /* FIXME: Locking */
 272         if (serial->num_bulk_out) {
 273                 if (!(port->write_urb_busy))
 274                         room = port->bulk_out_size;
 275         }
 276
 277         dbg("%s - returns %d", __func__, room);
 278         return room;
 279 }
 280
 281 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 282 {
 283         struct usb_serial_port *port = tty->driver_data;
 284         struct usb_serial *serial = port->serial;
 285         int chars = 0;
 286
 287         dbg("%s - port %d", __func__, port->number);
 288
 289         /* FIXME: Locking */
 290         if (serial->num_bulk_out) {
 291                 if (port->write_urb_busy)
 292                         chars = port->write_urb->transfer_buffer_length;
 293         }
 294
 295         dbg("%s - returns %d", __func__, chars);
 296         return chars;
 297 }
 298
 299
 300 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 301 {
 302         struct urb *urb = port->read_urb;
 303         struct usb_serial *serial = port->serial;
 304         int result;
 305
 306         /* Continue reading from device */
 307         usb_fill_bulk_urb(urb, serial->dev,
 308                            usb_rcvbulkpipe(serial->dev,
 309                                         port->bulk_in_endpointAddress),
 310                            urb->transfer_buffer,
 311                            urb->transfer_buffer_length,
 312                            ((serial->type->read_bulk_callback) ?
 313                              serial->type->read_bulk_callback :
 314                              usb_serial_generic_read_bulk_callback), port);
 315         result = usb_submit_urb(urb, mem_flags);
 316         if (result)
 317                 dev_err(&port->dev,
 318                         "%s - failed resubmitting read urb, error %d\n",
 319                                                         __func__, result);
 320 }
 321
 322 /* Push data to tty layer and resubmit the bulk read URB */
 323 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 324 {
 325         struct urb *urb = port->read_urb;
 326         struct tty_struct *tty = tty_port_tty_get(&port->port);
 327         int room;
 328
 329         /* Push data to tty */
 330         if (tty && urb->actual_length) {
 331                 room = tty_buffer_request_room(tty, urb->actual_length);
 332                 if (room) {
 333                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 334                         tty_flip_buffer_push(tty);
 335                 }
 336         }
 337         tty_kref_put(tty);
 338
 339         resubmit_read_urb(port, GFP_ATOMIC);
 340 }
 341
 342 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 343 {
 344         struct usb_serial_port *port = urb->context;
 345         unsigned char *data = urb->transfer_buffer;
 346         int status = urb->status;
 347         unsigned long flags;
 348
 349         dbg("%s - port %d", __func__, port->number);
 350
 351         if (unlikely(status != 0)) {
 352                 dbg("%s - nonzero read bulk status received: %d",
 353                     __func__, status);
 354                 return;
 355         }
 356
 357         usb_serial_debug_data(debug, &port->dev, __func__,
 358                                                 urb->actual_length, data);
 359
 360         /* Throttle the device if requested by tty */
 361         spin_lock_irqsave(&port->lock, flags);
 362         port->throttled = port->throttle_req;
 363         if (!port->throttled) {
 364                 spin_unlock_irqrestore(&port->lock, flags);
 365                 flush_and_resubmit_read_urb(port);
 366         } else
 367                 spin_unlock_irqrestore(&port->lock, flags);
 368 }
 369 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 370
 371 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 372 {
 373         struct usb_serial_port *port = urb->context;
 374         int status = urb->status;
 375
 376         dbg("%s - port %d", __func__, port->number);
 377
 378         port->write_urb_busy = 0;
 379         if (status) {
 380                 dbg("%s - nonzero write bulk status received: %d",
 381                     __func__, status);
 382                 return;
 383         }
 384         usb_serial_port_softint(port);
 385 }
 386 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 387
 388 void usb_serial_generic_throttle(struct tty_struct *tty)
 389 {
 390         struct usb_serial_port *port = tty->driver_data;
 391         unsigned long flags;
 392
 393         dbg("%s - port %d", __func__, port->number);
 394
 395         /* Set the throttle request flag. It will be picked up
 396          * by usb_serial_generic_read_bulk_callback(). */
 397         spin_lock_irqsave(&port->lock, flags);
 398         port->throttle_req = 1;
 399         spin_unlock_irqrestore(&port->lock, flags);
 400 }
 401
 402 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 403 {
 404         struct usb_serial_port *port = tty->driver_data;
 405         int was_throttled;
 406         unsigned long flags;
 407
 408         dbg("%s - port %d", __func__, port->number);
 409
 410         /* Clear the throttle flags */
 411         spin_lock_irqsave(&port->lock, flags);
 412         was_throttled = port->throttled;
 413         port->throttled = port->throttle_req = 0;
 414         spin_unlock_irqrestore(&port->lock, flags);
 415
 416         if (was_throttled) {
 417                 /* Resume reading from device */
 418                 resubmit_read_urb(port, GFP_KERNEL);
 419         }
 420 }
 421
 422 void usb_serial_generic_shutdown(struct usb_serial *serial)
 423 {
 424         int i;
 425
 426         dbg("%s", __func__);
 427
 428         /* stop reads and writes on all ports */
 429         for (i = 0; i < serial->num_ports; ++i)
 430                 generic_cleanup(serial->port[i]);
 431 }
 432