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         /* clear the throttle flags */
 126         spin_lock_irqsave(&port->lock, flags);
 127         port->throttled = 0;
 128         port->throttle_req = 0;
 129         spin_unlock_irqrestore(&port->lock, flags);
 130
 131         /* if we have a bulk endpoint, start reading from it */
 132         if (serial->num_bulk_in) {
 133                 /* Start reading from the device */
 134                 usb_fill_bulk_urb(port->read_urb, serial->dev,
 135                                    usb_rcvbulkpipe(serial->dev,
 136                                                 port->bulk_in_endpointAddress),
 137                                    port->read_urb->transfer_buffer,
 138                                    port->read_urb->transfer_buffer_length,
 139                                    ((serial->type->read_bulk_callback) ?
 140                                      serial->type->read_bulk_callback :
 141                                      usb_serial_generic_read_bulk_callback),
 142                                    port);
 143                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 144                 if (result)
 145                         dev_err(&port->dev,
 146                             "%s - failed resubmitting read urb, error %d\n",
 147                                                         __func__, result);
 148         }
 149
 150         return result;
 151 }
 152 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
 153
 154 static void generic_cleanup(struct usb_serial_port *port)
 155 {
 156         struct usb_serial *serial = port->serial;
 157
 158         dbg("%s - port %d", __func__, port->number);
 159
 160         if (serial->dev) {
 161                 /* shutdown any bulk reads that might be going on */
 162                 if (serial->num_bulk_out)
 163                         usb_kill_urb(port->write_urb);
 164                 if (serial->num_bulk_in)
 165                         usb_kill_urb(port->read_urb);
 166         }
 167 }
 168
 169 int usb_serial_generic_resume(struct usb_serial *serial)
 170 {
 171         struct usb_serial_port *port;
 172         int i, c = 0, r;
 173
 174         for (i = 0; i < serial->num_ports; i++) {
 175                 port = serial->port[i];
 176                 if (port->port.count && port->read_urb) {
 177                         r = usb_submit_urb(port->read_urb, GFP_NOIO);
 178                         if (r < 0)
 179                                 c++;
 180                 }
 181         }
 182
 183         return c ? -EIO : 0;
 184 }
 185 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
 186
 187 void usb_serial_generic_close(struct usb_serial_port *port)
 188 {
 189         dbg("%s - port %d", __func__, port->number);
 190         generic_cleanup(port);
 191 }
 192
 193 int usb_serial_generic_write(struct tty_struct *tty,
 194         struct usb_serial_port *port, const unsigned char *buf, int count)
 195 {
 196         struct usb_serial *serial = port->serial;
 197         int result;
 198         unsigned char *data;
 199
 200         dbg("%s - port %d", __func__, port->number);
 201
 202         if (count == 0) {
 203                 dbg("%s - write request of 0 bytes", __func__);
 204                 return 0;
 205         }
 206
 207         /* only do something if we have a bulk out endpoint */
 208         if (serial->num_bulk_out) {
 209                 unsigned long flags;
 210                 spin_lock_irqsave(&port->lock, flags);
 211                 if (port->write_urb_busy) {
 212                         spin_unlock_irqrestore(&port->lock, flags);
 213                         dbg("%s - already writing", __func__);
 214                         return 0;
 215                 }
 216                 port->write_urb_busy = 1;
 217                 spin_unlock_irqrestore(&port->lock, flags);
 218
 219                 count = (count > port->bulk_out_size) ?
 220                                         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, __func__, 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),
 234                                    port);
 235
 236                 /* send the data out the bulk port */
 237                 port->write_urb_busy = 1;
 238                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 239                 if (result) {
 240                         dev_err(&port->dev,
 241                                 "%s - failed submitting write urb, error %d\n",
 242                                                         __func__, result);
 243                         /* don't have to grab the lock here, as we will
 244                            retry if != 0 */
 245                         port->write_urb_busy = 0;
 246                 } else
 247                         result = count;
 248
 249                 return result;
 250         }
 251
 252         /* no bulk out, so return 0 bytes written */
 253         return 0;
 254 }
 255
 256 int usb_serial_generic_write_room(struct tty_struct *tty)
 257 {
 258         struct usb_serial_port *port = tty->driver_data;
 259         struct usb_serial *serial = port->serial;
 260         int room = 0;
 261
 262         dbg("%s - port %d", __func__, port->number);
 263
 264         /* FIXME: Locking */
 265         if (serial->num_bulk_out) {
 266                 if (!(port->write_urb_busy))
 267                         room = port->bulk_out_size;
 268         }
 269
 270         dbg("%s - returns %d", __func__, room);
 271         return room;
 272 }
 273
 274 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 275 {
 276         struct usb_serial_port *port = tty->driver_data;
 277         struct usb_serial *serial = port->serial;
 278         int chars = 0;
 279
 280         dbg("%s - port %d", __func__, port->number);
 281
 282         /* FIXME: Locking */
 283         if (serial->num_bulk_out) {
 284                 if (port->write_urb_busy)
 285                         chars = port->write_urb->transfer_buffer_length;
 286         }
 287
 288         dbg("%s - returns %d", __func__, chars);
 289         return chars;
 290 }
 291
 292
 293 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
 294 {
 295         struct urb *urb = port->read_urb;
 296         struct usb_serial *serial = port->serial;
 297         int result;
 298
 299         /* Continue reading from device */
 300         usb_fill_bulk_urb(urb, serial->dev,
 301                            usb_rcvbulkpipe(serial->dev,
 302                                         port->bulk_in_endpointAddress),
 303                            urb->transfer_buffer,
 304                            urb->transfer_buffer_length,
 305                            ((serial->type->read_bulk_callback) ?
 306                              serial->type->read_bulk_callback :
 307                              usb_serial_generic_read_bulk_callback), port);
 308         result = usb_submit_urb(urb, mem_flags);
 309         if (result)
 310                 dev_err(&port->dev,
 311                         "%s - failed resubmitting read urb, error %d\n",
 312                                                         __func__, result);
 313 }
 314
 315 /* Push data to tty layer and resubmit the bulk read URB */
 316 static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
 317 {
 318         struct urb *urb = port->read_urb;
 319         struct tty_struct *tty = tty_port_tty_get(&port->port);
 320         int room;
 321
 322         /* Push data to tty */
 323         if (tty && urb->actual_length) {
 324                 room = tty_buffer_request_room(tty, urb->actual_length);
 325                 if (room) {
 326                         tty_insert_flip_string(tty, urb->transfer_buffer, room);
 327                         tty_flip_buffer_push(tty);
 328                 }
 329         }
 330         tty_kref_put(tty);
 331
 332         resubmit_read_urb(port, GFP_ATOMIC);
 333 }
 334
 335 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 336 {
 337         struct usb_serial_port *port = urb->context;
 338         unsigned char *data = urb->transfer_buffer;
 339         int status = urb->status;
 340         unsigned long flags;
 341
 342         dbg("%s - port %d", __func__, port->number);
 343
 344         if (unlikely(status != 0)) {
 345                 dbg("%s - nonzero read bulk status received: %d",
 346                     __func__, status);
 347                 return;
 348         }
 349
 350         usb_serial_debug_data(debug, &port->dev, __func__,
 351                                                 urb->actual_length, data);
 352
 353         /* Throttle the device if requested by tty */
 354         spin_lock_irqsave(&port->lock, flags);
 355         port->throttled = port->throttle_req;
 356         if (!port->throttled) {
 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 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
 363
 364 void usb_serial_generic_write_bulk_callback(struct urb *urb)
 365 {
 366         struct usb_serial_port *port = urb->context;
 367         int status = urb->status;
 368
 369         dbg("%s - port %d", __func__, port->number);
 370
 371         port->write_urb_busy = 0;
 372         if (status) {
 373                 dbg("%s - nonzero write bulk status received: %d",
 374                     __func__, status);
 375                 return;
 376         }
 377         usb_serial_port_softint(port);
 378 }
 379 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 380
 381 void usb_serial_generic_throttle(struct tty_struct *tty)
 382 {
 383         struct usb_serial_port *port = tty->driver_data;
 384         unsigned long flags;
 385
 386         dbg("%s - port %d", __func__, port->number);
 387
 388         /* Set the throttle request flag. It will be picked up
 389          * by usb_serial_generic_read_bulk_callback(). */
 390         spin_lock_irqsave(&port->lock, flags);
 391         port->throttle_req = 1;
 392         spin_unlock_irqrestore(&port->lock, flags);
 393 }
 394
 395 void usb_serial_generic_unthrottle(struct tty_struct *tty)
 396 {
 397         struct usb_serial_port *port = tty->driver_data;
 398         int was_throttled;
 399         unsigned long flags;
 400
 401         dbg("%s - port %d", __func__, port->number);
 402
 403         /* Clear the throttle flags */
 404         spin_lock_irqsave(&port->lock, flags);
 405         was_throttled = port->throttled;
 406         port->throttled = port->throttle_req = 0;
 407         spin_unlock_irqrestore(&port->lock, flags);
 408
 409         if (was_throttled) {
 410                 /* Resume reading from device */
 411                 resubmit_read_urb(port, GFP_KERNEL);
 412         }
 413 }
 414
 415 void usb_serial_generic_shutdown(struct usb_serial *serial)
 416 {
 417         int i;
 418
 419         dbg("%s", __func__);
 420
 421         /* stop reads and writes on all ports */
 422         for (i = 0; i < serial->num_ports; ++i)
 423                 generic_cleanup(serial->port[i]);
 424 }
 425