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_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 = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  93
  94         /* register our generic driver with ourselves */
  95         retval = usb_serial_register (&usb_serial_generic_device);
  96         if (retval)
  97                 goto exit;
  98         retval = usb_register(&generic_driver);
  99         if (retval)
 100                 usb_serial_deregister(&usb_serial_generic_device);
 101 exit:
 102 #endif
 103         return retval;
 104 }
 105
 106 void usb_serial_generic_deregister (void)
 107 {
 108 #ifdef CONFIG_USB_SERIAL_GENERIC
 109         /* remove our generic driver */
 110         usb_deregister(&generic_driver);
 111         usb_serial_deregister (&usb_serial_generic_device);
 112 #endif
 113 }
 114
 115 int usb_serial_generic_open(struct tty_struct *tty,
 116                         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", __func__, 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 (tty)
 128                 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", __func__, 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", __func__, 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 int usb_serial_generic_resume(struct usb_serial *serial)
 172 {
 173         struct usb_serial_port *port;
 174         int i, c = 0, r;
 175
 176 #ifdef CONFIG_PM
 177         /*
 178          * If this is an autoresume, don't submit URBs.
 179          * They will be submitted in the open function instead.
 180          */
 181         if (serial->dev->auto_pm)
 182                 return 0;
 183 #endif
 184         for (i = 0; i < serial->num_ports; i++) {
 185                 port = serial->port[i];
 186                 if (port->port.count && port->read_urb) {
 187                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 188                         if (r < 0)
 189                                 c++;
 190                 }
 191         }
 192
 193         return c ? -EIO : 0;
 194 }
 195
 196 void usb_serial_generic_close(struct tty_struct *tty,
 197                         struct usb_serial_port *port, struct file * filp)
 198 {
 199         dbg("%s - port %d", __func__, port->number);
 200         generic_cleanup (port);
 201 }
 202
 203 int usb_serial_generic_write(struct tty_struct *tty,
 204         struct usb_serial_port *port, const unsigned char *buf, int count)
 205 {
 206         struct usb_serial *serial = port->serial;
 207         int result;
 208         unsigned char *data;
 209
 210         dbg("%s - port %d", __func__, port->number);
 211
 212         if (count == 0) {
 213                 dbg("%s - write request of 0 bytes", __func__);
 214                 return (0);
 215         }
 216
 217         /* only do something if we have a bulk out endpoint */
 218         if (serial->num_bulk_out) {
 219                 unsigned long flags;
 220                 spin_lock_irqsave(&port->lock, flags);
 221                 if (port->write_urb_busy) {
 222                         spin_unlock_irqrestore(&port->lock, flags);
 223                         dbg("%s - already writing", __func__);
 224                         return 0;
 225                 }
 226                 port->write_urb_busy = 1;
 227                 spin_unlock_irqrestore(&port->lock, flags);
 228
 229                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 230
 231                 memcpy (port->write_urb->transfer_buffer, buf, count);
 232                 data = port->write_urb->transfer_buffer;
 233                 usb_serial_debug_data(debug, &port->dev, __func__, count, data);
 234
 235                 /* set up our urb */
 236                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 237                                    usb_sndbulkpipe (serial->dev,
 238                                                     port->bulk_out_endpointAddress),
 239                                    port->write_urb->transfer_buffer, count,
 240                                    ((serial->type->write_bulk_callback) ?
 241                                      serial->type->write_bulk_callback :
 242                                      usb_serial_generic_write_bulk_callback), port);
 243
 244                 /* send the data out the bulk port */
 245                 port->write_urb_busy = 1;
 246                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 247                 if (result) {
 248                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __func__, result);
 249                         /* don't have to grab the lock here, as we will retry if != 0 */
 250                         port->write_urb_busy = 0;
 251                 } else
 252                         result = count;
 253
 254                 return result;
 255         }
 256
 257         /* no bulk out, so return 0 bytes written */
 258         return 0;
 259 }
 260
 261 int usb_serial_generic_write_room (struct tty_struct *tty)
 262 {
 263         struct usb_serial_port *port = tty->driver_data;
 264         struct usb_serial *serial = port->serial;
 265         int room = 0;
 266
 267         dbg("%s - port %d", __func__, port->number);
 268
 269         /* FIXME: Locking */
 270         if (serial->num_bulk_out) {
 271                 if (!(port->write_urb_busy))
 272                         room = port->bulk_out_size;
 273         }
 274
 275         dbg("%s - returns %d", __func__, room);
 276         return room;
 277 }
 278
 279 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 280 {
 281         struct usb_serial_port *port = tty->driver_data;
 282         struct usb_serial *serial = port->serial;
 283         int chars = 0;
 284
 285         dbg("%s - port %d", __func__, port->number);
 286
 287         /* FIXME: Locking */
 288         if (serial->num_bulk_out) {
 289                 if (port->write_urb_busy)
 290                         chars = port->write_urb->transfer_buffer_length;
 291         }
 292
 293         dbg("%s - returns %d", __func__, chars);
 294         return chars;
 295 }
 296
 297
 298 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 299 {
 300         struct urb *urb = port->read_urb;
 301         struct usb_serial *serial = port->serial;
 302         int result;
 303
 304         /* Continue reading from device */
 305         usb_fill_bulk_urb (urb, serial->dev,
 306                            usb_rcvbulkpipe (serial->dev,
 307                                             port->bulk_in_endpointAddress),
 308                            urb->transfer_buffer,
 309                            urb->transfer_buffer_length,
 310                            ((serial->type->read_bulk_callback) ?
 311                              serial->type->read_bulk_callback :
 312                              usb_serial_generic_read_bulk_callback), port);
 313         result = usb_submit_urb(urb, mem_flags);
 314         if (result)
 315                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __func__, result);
 316 }
 317
 318 /* Push data to tty layer and resubmit the bulk read URB */
 319 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 320 {
 321         struct urb *urb = port->read_urb;
 322         struct tty_struct *tty = port->port.tty;
 323         int room;
 324
 325         /* Push data to tty */
 326         if (tty && urb->actual_length) {
 327                 room = tty_buffer_request_room(tty, urb->actual_length);
 328                 if (room) {
 329                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 330                         tty_flip_buffer_push(tty);
 331                 }
 332         }
 333
 334         resubmit_read_urb(port, GFP_ATOMIC);
 335 }
 336
 337 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 338 {
 339         struct usb_serial_port *port = urb->context;
 340         unsigned char *data = urb->transfer_buffer;
 341         int status = urb->status;
 342         unsigned long flags;
 343
 344         dbg("%s - port %d", __func__, port->number);
 345
 346         if (unlikely(status != 0)) {
 347                 dbg("%s - nonzero read bulk status received: %d",
 348                     __func__, status);
 349                 return;
 350         }
 351
 352         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, data);
 353
 354         /* Throttle the device if requested by tty */
 355         spin_lock_irqsave(&port->lock, flags);
 356         if (!(port->throttled = port->throttle_req)) {
 357                 spin_unlock_irqrestore(&port->lock, flags);
 358                 flush_and_resubmit_read_urb(port);
 359         } else {
 360                 spin_unlock_irqrestore(&port->lock, flags);
 361         }
 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 }
 427