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         for (i = 0; i < serial->num_ports; i++) {
 179                 port = serial->port[i];
 180                 if (port->open_count && port->read_urb) {
 181                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 182                         if (r < 0)
 183                                 c++;
 184                 }
 185         }
 186
 187         return c ? -EIO : 0;
 188 }
 189
 190 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 191 {
 192         dbg("%s - port %d", __FUNCTION__, port->number);
 193         generic_cleanup (port);
 194 }
 195
 196 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 197 {
 198         struct usb_serial *serial = port->serial;
 199         int result;
 200         unsigned char *data;
 201
 202         dbg("%s - port %d", __FUNCTION__, port->number);
 203
 204         if (count == 0) {
 205                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 206                 return (0);
 207         }
 208
 209         /* only do something if we have a bulk out endpoint */
 210         if (serial->num_bulk_out) {
 211                 spin_lock_bh(&port->lock);
 212                 if (port->write_urb_busy) {
 213                         spin_unlock_bh(&port->lock);
 214                         dbg("%s - already writing", __FUNCTION__);
 215                         return 0;
 216                 }
 217                 port->write_urb_busy = 1;
 218                 spin_unlock_bh(&port->lock);
 219
 220                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 221
 222                 memcpy (port->write_urb->transfer_buffer, buf, count);
 223                 data = port->write_urb->transfer_buffer;
 224                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
 225
 226                 /* set up our urb */
 227                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 228                                    usb_sndbulkpipe (serial->dev,
 229                                                     port->bulk_out_endpointAddress),
 230                                    port->write_urb->transfer_buffer, count,
 231                                    ((serial->type->write_bulk_callback) ?
 232                                      serial->type->write_bulk_callback :
 233                                      usb_serial_generic_write_bulk_callback), port);
 234
 235                 /* send the data out the bulk port */
 236                 port->write_urb_busy = 1;
 237                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 238                 if (result) {
 239                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 240                         /* don't have to grab the lock here, as we will retry if != 0 */
 241                         port->write_urb_busy = 0;
 242                 } else
 243                         result = count;
 244
 245                 return result;
 246         }
 247
 248         /* no bulk out, so return 0 bytes written */
 249         return 0;
 250 }
 251
 252 int usb_serial_generic_write_room (struct usb_serial_port *port)
 253 {
 254         struct usb_serial *serial = port->serial;
 255         int room = 0;
 256
 257         dbg("%s - port %d", __FUNCTION__, port->number);
 258
 259         if (serial->num_bulk_out) {
 260                 if (!(port->write_urb_busy))
 261                         room = port->bulk_out_size;
 262         }
 263
 264         dbg("%s - returns %d", __FUNCTION__, room);
 265         return (room);
 266 }
 267
 268 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 269 {
 270         struct usb_serial *serial = port->serial;
 271         int chars = 0;
 272
 273         dbg("%s - port %d", __FUNCTION__, port->number);
 274
 275         if (serial->num_bulk_out) {
 276                 if (port->write_urb_busy)
 277                         chars = port->write_urb->transfer_buffer_length;
 278         }
 279
 280         dbg("%s - returns %d", __FUNCTION__, chars);
 281         return (chars);
 282 }
 283
 284
 285 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 286 {
 287         struct urb *urb = port->read_urb;
 288         struct usb_serial *serial = port->serial;
 289         int result;
 290
 291         /* Continue reading from device */
 292         usb_fill_bulk_urb (urb, serial->dev,
 293                            usb_rcvbulkpipe (serial->dev,
 294                                             port->bulk_in_endpointAddress),
 295                            urb->transfer_buffer,
 296                            urb->transfer_buffer_length,
 297                            ((serial->type->read_bulk_callback) ?
 298                              serial->type->read_bulk_callback :
 299                              usb_serial_generic_read_bulk_callback), port);
 300         result = usb_submit_urb(urb, mem_flags);
 301         if (result)
 302                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 303 }
 304
 305 /* Push data to tty layer and resubmit the bulk read URB */
 306 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
 307 {
 308         struct urb *urb = port->read_urb;
 309         struct tty_struct *tty = port->tty;
 310         int room;
 311
 312         /* Push data to tty */
 313         if (tty && urb->actual_length) {
 314                 room = tty_buffer_request_room(tty, urb->actual_length);
 315                 if (room) {
 316                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 317                         tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
 318                 }
 319         }
 320
 321         resubmit_read_urb(port, GFP_ATOMIC);
 322 }
 323
 324 void usb_serial_generic_read_bulk_callback (struct urb *urb)
 325 {
 326         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 327         unsigned char *data = urb->transfer_buffer;
 328         int status = urb->status;
 329
 330         dbg("%s - port %d", __FUNCTION__, port->number);
 331
 332         if (unlikely(status != 0)) {
 333                 dbg("%s - nonzero read bulk status received: %d",
 334                     __FUNCTION__, status);
 335                 return;
 336         }
 337
 338         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 339
 340         /* Throttle the device if requested by tty */
 341         spin_lock(&port->lock);
 342         if (!(port->throttled = port->throttle_req))
 343                 /* Handle data and continue reading from device */
 344                 flush_and_resubmit_read_urb(port);
 345         spin_unlock(&port->lock);
 346 }
 347 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 348
 349 void usb_serial_generic_write_bulk_callback (struct urb *urb)
 350 {
 351         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 352         int status = urb->status;
 353
 354         dbg("%s - port %d", __FUNCTION__, port->number);
 355
 356         port->write_urb_busy = 0;
 357         if (status) {
 358                 dbg("%s - nonzero write bulk status received: %d",
 359                     __FUNCTION__, status);
 360                 return;
 361         }
 362
 363         usb_serial_port_softint(port);
 364 }
 365 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 366
 367 void usb_serial_generic_throttle (struct usb_serial_port *port)
 368 {
 369         unsigned long flags;
 370
 371         dbg("%s - port %d", __FUNCTION__, port->number);
 372
 373         /* Set the throttle request flag. It will be picked up
 374          * by usb_serial_generic_read_bulk_callback(). */
 375         spin_lock_irqsave(&port->lock, flags);
 376         port->throttle_req = 1;
 377         spin_unlock_irqrestore(&port->lock, flags);
 378 }
 379
 380 void usb_serial_generic_unthrottle (struct usb_serial_port *port)
 381 {
 382         int was_throttled;
 383         unsigned long flags;
 384
 385         dbg("%s - port %d", __FUNCTION__, port->number);
 386
 387         /* Clear the throttle flags */
 388         spin_lock_irqsave(&port->lock, flags);
 389         was_throttled = port->throttled;
 390         port->throttled = port->throttle_req = 0;
 391         spin_unlock_irqrestore(&port->lock, flags);
 392
 393         if (was_throttled) {
 394                 /* Resume reading from device */
 395                 resubmit_read_urb(port, GFP_KERNEL);
 396         }
 397 }
 398
 399 void usb_serial_generic_shutdown (struct usb_serial *serial)
 400 {
 401         int i;
 402
 403         dbg("%s", __FUNCTION__);
 404
 405         /* stop reads and writes on all ports */
 406         for (i=0; i < serial->num_ports; ++i) {
 407                 generic_cleanup(serial->port[i]);
 408         }
 409 }
 410