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 };
  73
  74 static int generic_probe(struct usb_interface *interface,
  75                                const struct usb_device_id *id)
  76 {
  77         const struct usb_device_id *id_pattern;
  78
  79         id_pattern = usb_match_id(interface, generic_device_ids);
  80         if (id_pattern != NULL)
  81                 return usb_serial_probe(interface, id);
  82         return -ENODEV;
  83 }
  84 #endif
  85
  86 int usb_serial_generic_register (int _debug)
  87 {
  88         int retval = 0;
  89
  90         debug = _debug;
  91 #ifdef CONFIG_USB_SERIAL_GENERIC
  92         generic_device_ids[0].idVendor = vendor;
  93         generic_device_ids[0].idProduct = product;
  94         generic_device_ids[0].match_flags = 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 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", __FUNCTION__, port->number);
 124
 125         /* force low_latency on so that our tty_push actually forces the data through,
 126            otherwise it is scheduled, and with high data rates (like with OHCI) data
 127            can get lost. */
 128         if (port->tty)
 129                 port->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, port->bulk_in_endpointAddress),
 142                                    port->read_urb->transfer_buffer,
 143                                    port->read_urb->transfer_buffer_length,
 144                                    ((serial->type->read_bulk_callback) ?
 145                                      serial->type->read_bulk_callback :
 146                                      usb_serial_generic_read_bulk_callback),
 147                                    port);
 148                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 149                 if (result)
 150                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 151         }
 152
 153         return result;
 154 }
 155 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 156
 157 static void generic_cleanup (struct usb_serial_port *port)
 158 {
 159         struct usb_serial *serial = port->serial;
 160
 161         dbg("%s - port %d", __FUNCTION__, port->number);
 162
 163         if (serial->dev) {
 164                 /* shutdown any bulk reads that might be going on */
 165                 if (serial->num_bulk_out)
 166                         usb_kill_urb(port->write_urb);
 167                 if (serial->num_bulk_in)
 168                         usb_kill_urb(port->read_urb);
 169         }
 170 }
 171
 172 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 173 {
 174         dbg("%s - port %d", __FUNCTION__, port->number);
 175         generic_cleanup (port);
 176 }
 177
 178 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 179 {
 180         struct usb_serial *serial = port->serial;
 181         int result;
 182         unsigned char *data;
 183
 184         dbg("%s - port %d", __FUNCTION__, port->number);
 185
 186         if (count == 0) {
 187                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 188                 return (0);
 189         }
 190
 191         /* only do something if we have a bulk out endpoint */
 192         if (serial->num_bulk_out) {
 193                 spin_lock_bh(&port->lock);
 194                 if (port->write_urb_busy) {
 195                         spin_unlock_bh(&port->lock);
 196                         dbg("%s - already writing", __FUNCTION__);
 197                         return 0;
 198                 }
 199                 port->write_urb_busy = 1;
 200                 spin_unlock_bh(&port->lock);
 201
 202                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 203
 204                 memcpy (port->write_urb->transfer_buffer, buf, count);
 205                 data = port->write_urb->transfer_buffer;
 206                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
 207
 208                 /* set up our urb */
 209                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 210                                    usb_sndbulkpipe (serial->dev,
 211                                                     port->bulk_out_endpointAddress),
 212                                    port->write_urb->transfer_buffer, count,
 213                                    ((serial->type->write_bulk_callback) ?
 214                                      serial->type->write_bulk_callback :
 215                                      usb_serial_generic_write_bulk_callback), port);
 216
 217                 /* send the data out the bulk port */
 218                 port->write_urb_busy = 1;
 219                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 220                 if (result) {
 221                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 222                         /* don't have to grab the lock here, as we will retry if != 0 */
 223                         port->write_urb_busy = 0;
 224                 } else
 225                         result = count;
 226
 227                 return result;
 228         }
 229
 230         /* no bulk out, so return 0 bytes written */
 231         return 0;
 232 }
 233
 234 int usb_serial_generic_write_room (struct usb_serial_port *port)
 235 {
 236         struct usb_serial *serial = port->serial;
 237         int room = 0;
 238
 239         dbg("%s - port %d", __FUNCTION__, port->number);
 240
 241         if (serial->num_bulk_out) {
 242                 if (!(port->write_urb_busy))
 243                         room = port->bulk_out_size;
 244         }
 245
 246         dbg("%s - returns %d", __FUNCTION__, room);
 247         return (room);
 248 }
 249
 250 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 251 {
 252         struct usb_serial *serial = port->serial;
 253         int chars = 0;
 254
 255         dbg("%s - port %d", __FUNCTION__, port->number);
 256
 257         if (serial->num_bulk_out) {
 258                 if (port->write_urb_busy)
 259                         chars = port->write_urb->transfer_buffer_length;
 260         }
 261
 262         dbg("%s - returns %d", __FUNCTION__, chars);
 263         return (chars);
 264 }
 265
 266 /* Push data to tty layer and resubmit the bulk read URB */
 267 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
 268 {
 269         struct usb_serial *serial = port->serial;
 270         struct urb *urb = port->read_urb;
 271         struct tty_struct *tty = port->tty;
 272         int result;
 273
 274         /* Push data to tty */
 275         if (tty && urb->actual_length) {
 276                 tty_buffer_request_room(tty, urb->actual_length);
 277                 tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
 278                 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
 279         }
 280
 281         /* Continue reading from device */
 282         usb_fill_bulk_urb (port->read_urb, serial->dev,
 283                            usb_rcvbulkpipe (serial->dev,
 284                                             port->bulk_in_endpointAddress),
 285                            port->read_urb->transfer_buffer,
 286                            port->read_urb->transfer_buffer_length,
 287                            ((serial->type->read_bulk_callback) ?
 288                              serial->type->read_bulk_callback :
 289                              usb_serial_generic_read_bulk_callback), port);
 290         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 291         if (result)
 292                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 293 }
 294
 295 void usb_serial_generic_read_bulk_callback (struct urb *urb)
 296 {
 297         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 298         unsigned char *data = urb->transfer_buffer;
 299         int is_throttled;
 300         unsigned long flags;
 301
 302         dbg("%s - port %d", __FUNCTION__, port->number);
 303
 304         if (urb->status) {
 305                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
 306                 return;
 307         }
 308
 309         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 310
 311         /* Throttle the device if requested by tty */
 312         if (urb->actual_length) {
 313                 spin_lock_irqsave(&port->lock, flags);
 314                 is_throttled = port->throttled = port->throttle_req;
 315                 spin_unlock_irqrestore(&port->lock, flags);
 316                 if (is_throttled) {
 317                         /* Let the received data linger in the read URB;
 318                          * usb_serial_generic_unthrottle() will pick it
 319                          * up later. */
 320                         dbg("%s - throttling device", __FUNCTION__);
 321                         return;
 322                 }
 323         }
 324
 325         /* Handle data and continue reading from device */
 326         flush_and_resubmit_read_urb(port);
 327 }
 328 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 329
 330 void usb_serial_generic_write_bulk_callback (struct urb *urb)
 331 {
 332         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 333
 334         dbg("%s - port %d", __FUNCTION__, port->number);
 335
 336         port->write_urb_busy = 0;
 337         if (urb->status) {
 338                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 339                 return;
 340         }
 341
 342         usb_serial_port_softint(port);
 343 }
 344 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 345
 346 void usb_serial_generic_throttle (struct usb_serial_port *port)
 347 {
 348         unsigned long flags;
 349
 350         dbg("%s - port %d", __FUNCTION__, port->number);
 351
 352         /* Set the throttle request flag. It will be picked up
 353          * by usb_serial_generic_read_bulk_callback(). */
 354         spin_lock_irqsave(&port->lock, flags);
 355         port->throttle_req = 1;
 356         spin_unlock_irqrestore(&port->lock, flags);
 357 }
 358
 359 void usb_serial_generic_unthrottle (struct usb_serial_port *port)
 360 {
 361         int was_throttled;
 362         unsigned long flags;
 363
 364         dbg("%s - port %d", __FUNCTION__, port->number);
 365
 366         /* Clear the throttle flags */
 367         spin_lock_irqsave(&port->lock, flags);
 368         was_throttled = port->throttled;
 369         port->throttled = port->throttle_req = 0;
 370         spin_unlock_irqrestore(&port->lock, flags);
 371
 372         if (was_throttled) {
 373                 /* Handle pending data and resume reading from device */
 374                 flush_and_resubmit_read_urb(port);
 375         }
 376 }
 377
 378 void usb_serial_generic_shutdown (struct usb_serial *serial)
 379 {
 380         int i;
 381
 382         dbg("%s", __FUNCTION__);
 383
 384         /* stop reads and writes on all ports */
 385         for (i=0; i < serial->num_ports; ++i) {
 386                 generic_cleanup(serial->port[i]);
 387         }
 388 }
 389