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 static int generic_probe(struct usb_interface *interface,
  24                          const struct usb_device_id *id);
  25
  26
  27 static int debug;
  28
  29 #ifdef CONFIG_USB_SERIAL_GENERIC
  30 static __u16 vendor  = 0x05f9;
  31 static __u16 product = 0xffff;
  32
  33 module_param(vendor, ushort, 0);
  34 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
  35
  36 module_param(product, ushort, 0);
  37 MODULE_PARM_DESC(product, "User specified USB idProduct");
  38
  39 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
  40
  41 /* we want to look at all devices, as the vendor/product id can change
  42  * depending on the command line argument */
  43 static struct usb_device_id generic_serial_ids[] = {
  44         {.driver_info = 42},
  45         {}
  46 };
  47
  48 static struct usb_driver generic_driver = {
  49         .name =         "usbserial_generic",
  50         .probe =        generic_probe,
  51         .disconnect =   usb_serial_disconnect,
  52         .id_table =     generic_serial_ids,
  53         .no_dynamic_id =        1,
  54 };
  55
  56 /* All of the device info needed for the Generic Serial Converter */
  57 struct usb_serial_driver usb_serial_generic_device = {
  58         .driver = {
  59                 .owner =        THIS_MODULE,
  60                 .name =         "generic",
  61         },
  62         .id_table =             generic_device_ids,
  63         .usb_driver =           &generic_driver,
  64         .num_interrupt_in =     NUM_DONT_CARE,
  65         .num_bulk_in =          NUM_DONT_CARE,
  66         .num_bulk_out =         NUM_DONT_CARE,
  67         .num_ports =            1,
  68         .shutdown =             usb_serial_generic_shutdown,
  69         .throttle =             usb_serial_generic_throttle,
  70         .unthrottle =           usb_serial_generic_unthrottle,
  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 = 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 usb_serial_port *port, struct file *filp)
 117 {
 118         struct usb_serial *serial = port->serial;
 119         int result = 0;
 120         unsigned long flags;
 121
 122         dbg("%s - port %d", __FUNCTION__, port->number);
 123
 124         /* force low_latency on so that our tty_push actually forces the data through,
 125            otherwise it is scheduled, and with high data rates (like with OHCI) data
 126            can get lost. */
 127         if (port->tty)
 128                 port->tty->low_latency = 1;
 129
 130         /* clear the throttle flags */
 131         spin_lock_irqsave(&port->lock, flags);
 132         port->throttled = 0;
 133         port->throttle_req = 0;
 134         spin_unlock_irqrestore(&port->lock, flags);
 135
 136         /* if we have a bulk endpoint, start reading from it */
 137         if (serial->num_bulk_in) {
 138                 /* Start reading from the device */
 139                 usb_fill_bulk_urb (port->read_urb, serial->dev,
 140                                    usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
 141                                    port->read_urb->transfer_buffer,
 142                                    port->read_urb->transfer_buffer_length,
 143                                    ((serial->type->read_bulk_callback) ?
 144                                      serial->type->read_bulk_callback :
 145                                      usb_serial_generic_read_bulk_callback),
 146                                    port);
 147                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 148                 if (result)
 149                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 150         }
 151
 152         return result;
 153 }
 154 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 155
 156 static void generic_cleanup (struct usb_serial_port *port)
 157 {
 158         struct usb_serial *serial = port->serial;
 159
 160         dbg("%s - port %d", __FUNCTION__, port->number);
 161
 162         if (serial->dev) {
 163                 /* shutdown any bulk reads that might be going on */
 164                 if (serial->num_bulk_out)
 165                         usb_kill_urb(port->write_urb);
 166                 if (serial->num_bulk_in)
 167                         usb_kill_urb(port->read_urb);
 168         }
 169 }
 170
 171 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 172 {
 173         dbg("%s - port %d", __FUNCTION__, port->number);
 174         generic_cleanup (port);
 175 }
 176
 177 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 178 {
 179         struct usb_serial *serial = port->serial;
 180         int result;
 181         unsigned char *data;
 182
 183         dbg("%s - port %d", __FUNCTION__, port->number);
 184
 185         if (count == 0) {
 186                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 187                 return (0);
 188         }
 189
 190         /* only do something if we have a bulk out endpoint */
 191         if (serial->num_bulk_out) {
 192                 spin_lock_bh(&port->lock);
 193                 if (port->write_urb_busy) {
 194                         spin_unlock_bh(&port->lock);
 195                         dbg("%s - already writing", __FUNCTION__);
 196                         return 0;
 197                 }
 198                 port->write_urb_busy = 1;
 199                 spin_unlock_bh(&port->lock);
 200
 201                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 202
 203                 memcpy (port->write_urb->transfer_buffer, buf, count);
 204                 data = port->write_urb->transfer_buffer;
 205                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
 206
 207                 /* set up our urb */
 208                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 209                                    usb_sndbulkpipe (serial->dev,
 210                                                     port->bulk_out_endpointAddress),
 211                                    port->write_urb->transfer_buffer, count,
 212                                    ((serial->type->write_bulk_callback) ?
 213                                      serial->type->write_bulk_callback :
 214                                      usb_serial_generic_write_bulk_callback), port);
 215
 216                 /* send the data out the bulk port */
 217                 port->write_urb_busy = 1;
 218                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 219                 if (result) {
 220                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 221                         /* don't have to grab the lock here, as we will retry if != 0 */
 222                         port->write_urb_busy = 0;
 223                 } else
 224                         result = count;
 225
 226                 return result;
 227         }
 228
 229         /* no bulk out, so return 0 bytes written */
 230         return 0;
 231 }
 232
 233 int usb_serial_generic_write_room (struct usb_serial_port *port)
 234 {
 235         struct usb_serial *serial = port->serial;
 236         int room = 0;
 237
 238         dbg("%s - port %d", __FUNCTION__, port->number);
 239
 240         if (serial->num_bulk_out) {
 241                 if (!(port->write_urb_busy))
 242                         room = port->bulk_out_size;
 243         }
 244
 245         dbg("%s - returns %d", __FUNCTION__, room);
 246         return (room);
 247 }
 248
 249 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 250 {
 251         struct usb_serial *serial = port->serial;
 252         int chars = 0;
 253
 254         dbg("%s - port %d", __FUNCTION__, port->number);
 255
 256         if (serial->num_bulk_out) {
 257                 if (port->write_urb_busy)
 258                         chars = port->write_urb->transfer_buffer_length;
 259         }
 260
 261         dbg("%s - returns %d", __FUNCTION__, chars);
 262         return (chars);
 263 }
 264
 265 /* Push data to tty layer and resubmit the bulk read URB */
 266 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
 267 {
 268         struct usb_serial *serial = port->serial;
 269         struct urb *urb = port->read_urb;
 270         struct tty_struct *tty = port->tty;
 271         int result;
 272
 273         /* Push data to tty */
 274         if (tty && urb->actual_length) {
 275                 tty_buffer_request_room(tty, urb->actual_length);
 276                 tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
 277                 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
 278         }
 279
 280         /* Continue reading from device */
 281         usb_fill_bulk_urb (port->read_urb, serial->dev,
 282                            usb_rcvbulkpipe (serial->dev,
 283                                             port->bulk_in_endpointAddress),
 284                            port->read_urb->transfer_buffer,
 285                            port->read_urb->transfer_buffer_length,
 286                            ((serial->type->read_bulk_callback) ?
 287                              serial->type->read_bulk_callback :
 288                              usb_serial_generic_read_bulk_callback), port);
 289         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 290         if (result)
 291                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 292 }
 293
 294 void usb_serial_generic_read_bulk_callback (struct urb *urb)
 295 {
 296         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 297         unsigned char *data = urb->transfer_buffer;
 298         int is_throttled;
 299         unsigned long flags;
 300
 301         dbg("%s - port %d", __FUNCTION__, port->number);
 302
 303         if (urb->status) {
 304                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
 305                 return;
 306         }
 307
 308         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 309
 310         /* Throttle the device if requested by tty */
 311         if (urb->actual_length) {
 312                 spin_lock_irqsave(&port->lock, flags);
 313                 is_throttled = port->throttled = port->throttle_req;
 314                 spin_unlock_irqrestore(&port->lock, flags);
 315                 if (is_throttled) {
 316                         /* Let the received data linger in the read URB;
 317                          * usb_serial_generic_unthrottle() will pick it
 318                          * up later. */
 319                         dbg("%s - throttling device", __FUNCTION__);
 320                         return;
 321                 }
 322         }
 323
 324         /* Handle data and continue reading from device */
 325         flush_and_resubmit_read_urb(port);
 326 }
 327 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 328
 329 void usb_serial_generic_write_bulk_callback (struct urb *urb)
 330 {
 331         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 332
 333         dbg("%s - port %d", __FUNCTION__, port->number);
 334
 335         port->write_urb_busy = 0;
 336         if (urb->status) {
 337                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 338                 return;
 339         }
 340
 341         usb_serial_port_softint(port);
 342 }
 343 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 344
 345 void usb_serial_generic_throttle (struct usb_serial_port *port)
 346 {
 347         unsigned long flags;
 348
 349         dbg("%s - port %d", __FUNCTION__, port->number);
 350
 351         /* Set the throttle request flag. It will be picked up
 352          * by usb_serial_generic_read_bulk_callback(). */
 353         spin_lock_irqsave(&port->lock, flags);
 354         port->throttle_req = 1;
 355         spin_unlock_irqrestore(&port->lock, flags);
 356 }
 357
 358 void usb_serial_generic_unthrottle (struct usb_serial_port *port)
 359 {
 360         int was_throttled;
 361         unsigned long flags;
 362
 363         dbg("%s - port %d", __FUNCTION__, port->number);
 364
 365         /* Clear the throttle flags */
 366         spin_lock_irqsave(&port->lock, flags);
 367         was_throttled = port->throttled;
 368         port->throttled = port->throttle_req = 0;
 369         spin_unlock_irqrestore(&port->lock, flags);
 370
 371         if (was_throttled) {
 372                 /* Handle pending data and resume reading from device */
 373                 flush_and_resubmit_read_urb(port);
 374         }
 375 }
 376
 377 void usb_serial_generic_shutdown (struct usb_serial *serial)
 378 {
 379         int i;
 380
 381         dbg("%s", __FUNCTION__);
 382
 383         /* stop reads and writes on all ports */
 384         for (i=0; i < serial->num_ports; ++i) {
 385                 generic_cleanup(serial->port[i]);
 386         }
 387 }
 388