drivers/usb/serial/omninet.c

   1 /*
   2  * USB ZyXEL omni.net LCD PLUS driver
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License version
   6  *      2 as published by the Free Software Foundation.
   7  *
   8  * See Documentation/usb/usb-serial.txt for more information on using this
   9  * driver
  10  *
  11  * Please report both successes and troubles to the author at omninet@kroah.com
  12  *
  13  * (05/30/2001) gkh
  14  *      switched from using spinlock to a semaphore, which fixes lots of
  15  *      problems.
  16  *
  17  * (04/08/2001) gb
  18  *      Identify version on module load.
  19  *
  20  * (11/01/2000) Adam J. Richter
  21  *      usb_device_id table support
  22  *
  23  * (10/05/2000) gkh
  24  *      Fixed bug with urb->dev not being set properly, now that the usb
  25  *      core needs it.
  26  *
  27  * (08/28/2000) gkh
  28  *      Added locks for SMP safeness.
  29  *      Fixed MOD_INC and MOD_DEC logic and the ability to open a port more
  30  *      than once.
  31  *      Fixed potential race in omninet_write_bulk_callback
  32  *
  33  * (07/19/2000) gkh
  34  *      Added module_init and module_exit functions to handle the fact that this
  35  *      driver is a loadable module now.
  36  *
  37  */
  38
  39 #include <linux/kernel.h>
  40 #include <linux/errno.h>
  41 #include <linux/init.h>
  42 #include <linux/slab.h>
  43 #include <linux/tty.h>
  44 #include <linux/tty_driver.h>
  45 #include <linux/tty_flip.h>
  46 #include <linux/module.h>
  47 #include <linux/spinlock.h>
  48 #include <linux/uaccess.h>
  49 #include <linux/usb.h>
  50 #include <linux/usb/serial.h>
  51
  52 static int debug;
  53
  54 /*
  55  * Version Information
  56  */
  57 #define DRIVER_VERSION "v1.1"
  58 #define DRIVER_AUTHOR "Alessandro Zummo"
  59 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
  60
  61 #define ZYXEL_VENDOR_ID         0x0586
  62 #define ZYXEL_OMNINET_ID        0x1000
  63 /* This one seems to be a re-branded ZyXEL device */
  64 #define BT_IGNITIONPRO_ID       0x2000
  65
  66 /* function prototypes */
  67 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port,
  68                                                         struct file *filp);
  69 static void omninet_close(struct tty_struct *tty, struct usb_serial_port *port,
  70                                                         struct file *filp);
  71 static void omninet_read_bulk_callback(struct urb *urb);
  72 static void omninet_write_bulk_callback(struct urb *urb);
  73 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  74                                 const unsigned char *buf, int count);
  75 static int  omninet_write_room(struct tty_struct *tty);
  76 static void omninet_shutdown(struct usb_serial *serial);
  77 static int omninet_attach(struct usb_serial *serial);
  78
  79 static struct usb_device_id id_table[] = {
  80         { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
  81         { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
  82         { }                                             /* Terminating entry */
  83 };
  84
  85 MODULE_DEVICE_TABLE(usb, id_table);
  86
  87 static struct usb_driver omninet_driver = {
  88         .name =         "omninet",
  89         .probe =        usb_serial_probe,
  90         .disconnect =   usb_serial_disconnect,
  91         .id_table =     id_table,
  92         .no_dynamic_id =        1,
  93 };
  94
  95
  96 static struct usb_serial_driver zyxel_omninet_device = {
  97         .driver = {
  98                 .owner =        THIS_MODULE,
  99                 .name =         "omninet",
 100         },
 101         .description =          "ZyXEL - omni.net lcd plus usb",
 102         .usb_driver =           &omninet_driver,
 103         .id_table =             id_table,
 104         .num_ports =            1,
 105         .attach =               omninet_attach,
 106         .open =                 omninet_open,
 107         .close =                omninet_close,
 108         .write =                omninet_write,
 109         .write_room =           omninet_write_room,
 110         .read_bulk_callback =   omninet_read_bulk_callback,
 111         .write_bulk_callback =  omninet_write_bulk_callback,
 112         .shutdown =             omninet_shutdown,
 113 };
 114
 115
 116 /* The protocol.
 117  *
 118  * The omni.net always exchange 64 bytes of data with the host. The first
 119  * four bytes are the control header, you can see it in the above structure.
 120  *
 121  * oh_seq is a sequence number. Don't know if/how it's used.
 122  * oh_len is the length of the data bytes in the packet.
 123  * oh_xxx Bit-mapped, related to handshaking and status info.
 124  *      I normally set it to 0x03 in trasmitted frames.
 125  *      7: Active when the TA is in a CONNECTed state.
 126  *      6: unknown
 127  *      5: handshaking, unknown
 128  *      4: handshaking, unknown
 129  *      3: unknown, usually 0
 130  *      2: unknown, usually 0
 131  *      1: handshaking, unknown, usually set to 1 in trasmitted frames
 132  *      0: handshaking, unknown, usually set to 1 in trasmitted frames
 133  * oh_pad Probably a pad byte.
 134  *
 135  * After the header you will find data bytes if oh_len was greater than zero.
 136  *
 137  */
 138
 139 struct omninet_header {
 140         __u8    oh_seq;
 141         __u8    oh_len;
 142         __u8    oh_xxx;
 143         __u8    oh_pad;
 144 };
 145
 146 struct omninet_data {
 147         __u8    od_outseq;      /* Sequence number for bulk_out URBs */
 148 };
 149
 150 static int omninet_attach(struct usb_serial *serial)
 151 {
 152         struct omninet_data *od;
 153         struct usb_serial_port *port = serial->port[0];
 154
 155         od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
 156         if (!od) {
 157                 err("%s- kmalloc(%Zd) failed.",
 158                                 __func__, sizeof(struct omninet_data));
 159                 return -ENOMEM;
 160         }
 161         usb_set_serial_port_data(port, od);
 162         return 0;
 163 }
 164
 165 static int omninet_open(struct tty_struct *tty,
 166                         struct usb_serial_port *port, struct file *filp)
 167 {
 168         struct usb_serial       *serial = port->serial;
 169         struct usb_serial_port  *wport;
 170         int                     result = 0;
 171
 172         dbg("%s - port %d", __func__, port->number);
 173
 174         wport = serial->port[1];
 175         tty_port_tty_set(&wport->port, tty);
 176
 177         /* Start reading from the device */
 178         usb_fill_bulk_urb(port->read_urb, serial->dev,
 179                         usb_rcvbulkpipe(serial->dev,
 180                                 port->bulk_in_endpointAddress),
 181                         port->read_urb->transfer_buffer,
 182                         port->read_urb->transfer_buffer_length,
 183                         omninet_read_bulk_callback, port);
 184         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 185         if (result)
 186                 err("%s - failed submitting read urb, error %d",
 187                                                         __func__, result);
 188         return result;
 189 }
 190
 191 static void omninet_close(struct tty_struct *tty,
 192                         struct usb_serial_port *port, struct file *filp)
 193 {
 194         dbg("%s - port %d", __func__, port->number);
 195         usb_kill_urb(port->read_urb);
 196 }
 197
 198
 199 #define OMNINET_DATAOFFSET      0x04
 200 #define OMNINET_HEADERLEN       sizeof(struct omninet_header)
 201 #define OMNINET_BULKOUTSIZE     (64 - OMNINET_HEADERLEN)
 202
 203 static void omninet_read_bulk_callback(struct urb *urb)
 204 {
 205         struct usb_serial_port  *port   = urb->context;
 206         unsigned char           *data   = urb->transfer_buffer;
 207         struct omninet_header   *header = (struct omninet_header *) &data[0];
 208         int status = urb->status;
 209         int result;
 210         int i;
 211
 212         dbg("%s - port %d", __func__, port->number);
 213
 214         if (status) {
 215                 dbg("%s - nonzero read bulk status received: %d",
 216                     __func__, status);
 217                 return;
 218         }
 219
 220         if (debug && header->oh_xxx != 0x30) {
 221                 if (urb->actual_length) {
 222                         printk(KERN_DEBUG __FILE__
 223                                         ": omninet_read %d: ", header->oh_len);
 224                         for (i = 0; i < (header->oh_len +
 225                                                 OMNINET_HEADERLEN); i++)
 226                                 printk("%.2x ", data[i]);
 227                         printk("\n");
 228                 }
 229         }
 230
 231         if (urb->actual_length && header->oh_len) {
 232                 struct tty_struct *tty = tty_port_tty_get(&port->port);
 233                 tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
 234                                                         header->oh_len);
 235                 tty_flip_buffer_push(tty);
 236                 tty_kref_put(tty);
 237         }
 238
 239         /* Continue trying to always read  */
 240         usb_fill_bulk_urb(urb, port->serial->dev,
 241                         usb_rcvbulkpipe(port->serial->dev,
 242                                         port->bulk_in_endpointAddress),
 243                         urb->transfer_buffer, urb->transfer_buffer_length,
 244                         omninet_read_bulk_callback, port);
 245         result = usb_submit_urb(urb, GFP_ATOMIC);
 246         if (result)
 247                 err("%s - failed resubmitting read urb, error %d",
 248                                                 __func__, result);
 249
 250         return;
 251 }
 252
 253 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 254                                         const unsigned char *buf, int count)
 255 {
 256         struct usb_serial *serial = port->serial;
 257         struct usb_serial_port *wport = serial->port[1];
 258
 259         struct omninet_data *od = usb_get_serial_port_data(port);
 260         struct omninet_header *header = (struct omninet_header *)
 261                                         wport->write_urb->transfer_buffer;
 262
 263         int                     result;
 264
 265         dbg("%s - port %d", __func__, port->number);
 266
 267         if (count == 0) {
 268                 dbg("%s - write request of 0 bytes", __func__);
 269                 return 0;
 270         }
 271
 272         spin_lock_bh(&wport->lock);
 273         if (wport->write_urb_busy) {
 274                 spin_unlock_bh(&wport->lock);
 275                 dbg("%s - already writing", __func__);
 276                 return 0;
 277         }
 278         wport->write_urb_busy = 1;
 279         spin_unlock_bh(&wport->lock);
 280
 281         count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
 282
 283         memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
 284                                                                 buf, count);
 285
 286         usb_serial_debug_data(debug, &port->dev, __func__, count,
 287                                         wport->write_urb->transfer_buffer);
 288
 289         header->oh_seq  = od->od_outseq++;
 290         header->oh_len  = count;
 291         header->oh_xxx  = 0x03;
 292         header->oh_pad  = 0x00;
 293
 294         /* send the data out the bulk port, always 64 bytes */
 295         wport->write_urb->transfer_buffer_length = 64;
 296
 297         wport->write_urb->dev = serial->dev;
 298         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 299         if (result) {
 300                 wport->write_urb_busy = 0;
 301                 err("%s - failed submitting write urb, error %d",
 302                                                         __func__, result);
 303         } else
 304                 result = count;
 305
 306         return result;
 307 }
 308
 309
 310 static int omninet_write_room(struct tty_struct *tty)
 311 {
 312         struct usb_serial_port *port = tty->driver_data;
 313         struct usb_serial       *serial = port->serial;
 314         struct usb_serial_port  *wport  = serial->port[1];
 315
 316         int room = 0; /* Default: no room */
 317
 318         /* FIXME: no consistent locking for write_urb_busy */
 319         if (wport->write_urb_busy)
 320                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 321
 322         dbg("%s - returns %d", __func__, room);
 323
 324         return room;
 325 }
 326
 327 static void omninet_write_bulk_callback(struct urb *urb)
 328 {
 329 /*      struct omninet_header   *header = (struct omninet_header  *)
 330                                                 urb->transfer_buffer; */
 331         struct usb_serial_port  *port   =  urb->context;
 332         int status = urb->status;
 333
 334         dbg("%s - port %0x\n", __func__, port->number);
 335
 336         port->write_urb_busy = 0;
 337         if (status) {
 338                 dbg("%s - nonzero write bulk status received: %d",
 339                     __func__, status);
 340                 return;
 341         }
 342
 343         usb_serial_port_softint(port);
 344 }
 345
 346
 347 static void omninet_shutdown(struct usb_serial *serial)
 348 {
 349         struct usb_serial_port *wport = serial->port[1];
 350         struct usb_serial_port *port = serial->port[0];
 351         dbg("%s", __func__);
 352
 353         usb_kill_urb(wport->write_urb);
 354         kfree(usb_get_serial_port_data(port));
 355 }
 356
 357
 358 static int __init omninet_init(void)
 359 {
 360         int retval;
 361         retval = usb_serial_register(&zyxel_omninet_device);
 362         if (retval)
 363                 goto failed_usb_serial_register;
 364         retval = usb_register(&omninet_driver);
 365         if (retval)
 366                 goto failed_usb_register;
 367         info(DRIVER_VERSION ":" DRIVER_DESC);
 368         return 0;
 369 failed_usb_register:
 370         usb_serial_deregister(&zyxel_omninet_device);
 371 failed_usb_serial_register:
 372         return retval;
 373 }
 374
 375
 376 static void __exit omninet_exit(void)
 377 {
 378         usb_deregister(&omninet_driver);
 379         usb_serial_deregister(&zyxel_omninet_device);
 380 }
 381
 382
 383 module_init(omninet_init);
 384 module_exit(omninet_exit);
 385
 386 MODULE_AUTHOR(DRIVER_AUTHOR);
 387 MODULE_DESCRIPTION(DRIVER_DESC);
 388 MODULE_LICENSE("GPL");
 389
 390 module_param(debug, bool, S_IRUGO | S_IWUSR);
 391 MODULE_PARM_DESC(debug, "Debug enabled or not");