drivers/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      Based on source code of the following authors:
   7  *        Ken Hollis <kenji@bitgate.com>,
   8  *        Alan Cox <alan@lxorguk.ukuu.org.uk>,
   9  *        Matt Domsch <Matt_Domsch@dell.com>,
  10  *        Rob Radez <rob@osinvestor.com>,
  11  *        Greg Kroah-Hartman <greg@kroah.com>
  12  *
  13  *      This program is free software; you can redistribute it and/or
  14  *      modify it under the terms of the GNU General Public License
  15  *      as published by the Free Software Foundation; either version
  16  *      2 of the License, or (at your option) any later version.
  17  *
  18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  19  *      provide warranty for any of this software. This material is
  20  *      provided "AS-IS" and at no charge.
  21  *
  22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  23  *      providing the test hardware. More info is available at
  24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  25  */
  26
  27 #include <linux/module.h>       /* For module specific items */
  28 #include <linux/moduleparam.h>  /* For new moduleparam's */
  29 #include <linux/types.h>        /* For standard types (like size_t) */
  30 #include <linux/errno.h>        /* For the -ENODEV/... values */
  31 #include <linux/kernel.h>       /* For printk/panic/... */
  32 #include <linux/delay.h>        /* For mdelay function */
  33 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  34 #include <linux/watchdog.h>     /* For the watchdog specific items */
  35 #include <linux/notifier.h>     /* For notifier support */
  36 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  37 #include <linux/init.h>         /* For __init/__exit/... */
  38 #include <linux/fs.h>           /* For file operations */
  39 #include <linux/usb.h>          /* For USB functions */
  40 #include <linux/slab.h>         /* For kmalloc, ... */
  41 #include <linux/mutex.h>        /* For mutex locking */
  42 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  43 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  44
  45
  46 #ifdef CONFIG_USB_DEBUG
  47         static int debug = 1;
  48 #else
  49         static int debug;
  50 #endif
  51
  52 /* Use our own dbg macro */
  53 #undef dbg
  54 #define dbg(format, arg...) \
  55         do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
  56
  57 /* Module and Version Information */
  58 #define DRIVER_VERSION "1.02"
  59 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  60 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  61 #define DRIVER_LICENSE "GPL"
  62 #define DRIVER_NAME "pcwd_usb"
  63 #define PFX DRIVER_NAME ": "
  64
  65 MODULE_AUTHOR(DRIVER_AUTHOR);
  66 MODULE_DESCRIPTION(DRIVER_DESC);
  67 MODULE_LICENSE(DRIVER_LICENSE);
  68 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
  69 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
  70
  71 /* Module Parameters */
  72 module_param(debug, int, 0);
  73 MODULE_PARM_DESC(debug, "Debug enabled or not");
  74
  75 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
  76                                                 delay-time from dip-switches */
  77 static int heartbeat = WATCHDOG_HEARTBEAT;
  78 module_param(heartbeat, int, 0);
  79 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
  80         "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
  81                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  82
  83 static int nowayout = WATCHDOG_NOWAYOUT;
  84 module_param(nowayout, int, 0);
  85 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  86                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  87
  88 /* The vendor and product id's for the USB-PC Watchdog card */
  89 #define USB_PCWD_VENDOR_ID      0x0c98
  90 #define USB_PCWD_PRODUCT_ID     0x1140
  91
  92 /* table of devices that work with this driver */
  93 static struct usb_device_id usb_pcwd_table[] = {
  94         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  95         { }                                     /* Terminating entry */
  96 };
  97 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
  98
  99 /* according to documentation max. time to process a command for the USB
 100  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
 101 #define USB_COMMAND_TIMEOUT     250
 102
 103 /* Watchdog's internal commands */
 104 #define CMD_READ_TEMP                   0x02    /* Read Temperature;
 105                                                         Re-trigger Watchdog */
 106 #define CMD_TRIGGER                     CMD_READ_TEMP
 107 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 108 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 109 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 110 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 111 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
 112 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 113 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 114
 115 /* Watchdog's Dip Switch heartbeat values */
 116 static const int heartbeat_tbl[] = {
 117         5,      /* OFF-OFF-OFF  =  5 Sec  */
 118         10,     /* OFF-OFF-ON   = 10 Sec  */
 119         30,     /* OFF-ON-OFF   = 30 Sec  */
 120         60,     /* OFF-ON-ON    =  1 Min  */
 121         300,    /* ON-OFF-OFF   =  5 Min  */
 122         600,    /* ON-OFF-ON    = 10 Min  */
 123         1800,   /* ON-ON-OFF    = 30 Min  */
 124         3600,   /* ON-ON-ON     =  1 hour */
 125 };
 126
 127 /* We can only use 1 card due to the /dev/watchdog restriction */
 128 static int cards_found;
 129
 130 /* some internal variables */
 131 static unsigned long is_active;
 132 static char expect_release;
 133
 134 /* Structure to hold all of our device specific stuff */
 135 struct usb_pcwd_private {
 136         /* save off the usb device pointer */
 137         struct usb_device       *udev;
 138         /* the interface for this device */
 139         struct usb_interface    *interface;
 140
 141         /* the interface number used for cmd's */
 142         unsigned int            interface_number;
 143
 144         /* the buffer to intr data */
 145         unsigned char           *intr_buffer;
 146         /* the dma address for the intr buffer */
 147         dma_addr_t              intr_dma;
 148         /* the size of the intr buffer */
 149         size_t                  intr_size;
 150         /* the urb used for the intr pipe */
 151         struct urb              *intr_urb;
 152
 153         /* The command that is reported back */
 154         unsigned char           cmd_command;
 155         /* The data MSB that is reported back */
 156         unsigned char           cmd_data_msb;
 157         /* The data LSB that is reported back */
 158         unsigned char           cmd_data_lsb;
 159         /* true if we received a report after a command */
 160         atomic_t                cmd_received;
 161
 162         /* Wether or not the device exists */
 163         int                     exists;
 164         /* locks this structure */
 165         struct mutex            mtx;
 166 };
 167 static struct usb_pcwd_private *usb_pcwd_device;
 168
 169 /* prevent races between open() and disconnect() */
 170 static DEFINE_MUTEX(disconnect_mutex);
 171
 172 /* local function prototypes */
 173 static int usb_pcwd_probe(struct usb_interface *interface,
 174                                                 const struct usb_device_id *id);
 175 static void usb_pcwd_disconnect(struct usb_interface *interface);
 176
 177 /* usb specific object needed to register this driver with the usb subsystem */
 178 static struct usb_driver usb_pcwd_driver = {
 179         .name =         DRIVER_NAME,
 180         .probe =        usb_pcwd_probe,
 181         .disconnect =   usb_pcwd_disconnect,
 182         .id_table =     usb_pcwd_table,
 183 };
 184
 185
 186 static void usb_pcwd_intr_done(struct urb *urb)
 187 {
 188         struct usb_pcwd_private *usb_pcwd =
 189                                 (struct usb_pcwd_private *)urb->context;
 190         unsigned char *data = usb_pcwd->intr_buffer;
 191         int retval;
 192
 193         switch (urb->status) {
 194         case 0:                 /* success */
 195                 break;
 196         case -ECONNRESET:       /* unlink */
 197         case -ENOENT:
 198         case -ESHUTDOWN:
 199                 /* this urb is terminated, clean up */
 200                 dbg("%s - urb shutting down with status: %d", __func__,
 201                                                                 urb->status);
 202                 return;
 203         /* -EPIPE:  should clear the halt */
 204         default:                /* error */
 205                 dbg("%s - nonzero urb status received: %d", __func__,
 206                                                                 urb->status);
 207                 goto resubmit;
 208         }
 209
 210         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 211                 data[0], data[1], data[2]);
 212
 213         usb_pcwd->cmd_command  = data[0];
 214         usb_pcwd->cmd_data_msb = data[1];
 215         usb_pcwd->cmd_data_lsb = data[2];
 216
 217         /* notify anyone waiting that the cmd has finished */
 218         atomic_set(&usb_pcwd->cmd_received, 1);
 219
 220 resubmit:
 221         retval = usb_submit_urb(urb, GFP_ATOMIC);
 222         if (retval)
 223                 printk(KERN_ERR PFX "can't resubmit intr, "
 224                         "usb_submit_urb failed with result %d\n", retval);
 225 }
 226
 227 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 228                 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 229 {
 230         int got_response, count;
 231         unsigned char buf[6];
 232
 233         /* We will not send any commands if the USB PCWD device does
 234          * not exist */
 235         if ((!usb_pcwd) || (!usb_pcwd->exists))
 236                 return -1;
 237
 238         /* The USB PC Watchdog uses a 6 byte report format.
 239          * The board currently uses only 3 of the six bytes of the report. */
 240         buf[0] = cmd;                   /* Byte 0 = CMD */
 241         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 242         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 243         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 244
 245         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 246                 buf[0], buf[1], buf[2]);
 247
 248         atomic_set(&usb_pcwd->cmd_received, 0);
 249
 250         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 251                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 252                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 253                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 254                 dbg("usb_pcwd_send_command: error in usb_control_msg for "
 255                                 "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 256         }
 257         /* wait till the usb card processed the command,
 258          * with a max. timeout of USB_COMMAND_TIMEOUT */
 259         got_response = 0;
 260         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
 261                                                                 count++) {
 262                 mdelay(1);
 263                 if (atomic_read(&usb_pcwd->cmd_received))
 264                         got_response = 1;
 265         }
 266
 267         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 268                 /* read back response */
 269                 *msb = usb_pcwd->cmd_data_msb;
 270                 *lsb = usb_pcwd->cmd_data_lsb;
 271         }
 272
 273         return got_response;
 274 }
 275
 276 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 277 {
 278         unsigned char msb = 0x00;
 279         unsigned char lsb = 0x00;
 280         int retval;
 281
 282         /* Enable Watchdog */
 283         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 284                                                                 &msb, &lsb);
 285
 286         if ((retval == 0) || (lsb == 0)) {
 287                 printk(KERN_ERR PFX
 288                                 "Card did not acknowledge enable attempt\n");
 289                 return -1;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 296 {
 297         unsigned char msb = 0xA5;
 298         unsigned char lsb = 0xC3;
 299         int retval;
 300
 301         /* Disable Watchdog */
 302         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 303                                                                 &msb, &lsb);
 304
 305         if ((retval == 0) || (lsb != 0)) {
 306                 printk(KERN_ERR PFX
 307                         "Card did not acknowledge disable attempt\n");
 308                 return -1;
 309         }
 310
 311         return 0;
 312 }
 313
 314 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 315 {
 316         unsigned char dummy;
 317
 318         /* Re-trigger Watchdog */
 319         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 320
 321         return 0;
 322 }
 323
 324 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 325 {
 326         unsigned char msb = t / 256;
 327         unsigned char lsb = t % 256;
 328
 329         if ((t < 0x0001) || (t > 0xFFFF))
 330                 return -EINVAL;
 331
 332         /* Write new heartbeat to watchdog */
 333         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 334
 335         heartbeat = t;
 336         return 0;
 337 }
 338
 339 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 340                                                         int *temperature)
 341 {
 342         unsigned char msb, lsb;
 343
 344         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 345
 346         /*
 347          * Convert celsius to fahrenheit, since this was
 348          * the decided 'standard' for this return value.
 349          */
 350         *temperature = (lsb * 9 / 5) + 32;
 351
 352         return 0;
 353 }
 354
 355 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 356                                                                 int *time_left)
 357 {
 358         unsigned char msb, lsb;
 359
 360         /* Read the time that's left before rebooting */
 361         /* Note: if the board is not yet armed then we will read 0xFFFF */
 362         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 363
 364         *time_left = (msb << 8) + lsb;
 365
 366         return 0;
 367 }
 368
 369 /*
 370  *      /dev/watchdog handling
 371  */
 372
 373 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 374                                                 size_t len, loff_t *ppos)
 375 {
 376         /* See if we got the magic character 'V' and reload the timer */
 377         if (len) {
 378                 if (!nowayout) {
 379                         size_t i;
 380
 381                         /* note: just in case someone wrote the magic character
 382                          * five months ago... */
 383                         expect_release = 0;
 384
 385                         /* scan to see whether or not we got the
 386                          * magic character */
 387                         for (i = 0; i != len; i++) {
 388                                 char c;
 389                                 if (get_user(c, data + i))
 390                                         return -EFAULT;
 391                                 if (c == 'V')
 392                                         expect_release = 42;
 393                         }
 394                 }
 395
 396                 /* someone wrote to us, we should reload the timer */
 397                 usb_pcwd_keepalive(usb_pcwd_device);
 398         }
 399         return len;
 400 }
 401
 402 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 403                                                 unsigned long arg)
 404 {
 405         void __user *argp = (void __user *)arg;
 406         int __user *p = argp;
 407         static const struct watchdog_info ident = {
 408                 .options =              WDIOF_KEEPALIVEPING |
 409                                         WDIOF_SETTIMEOUT |
 410                                         WDIOF_MAGICCLOSE,
 411                 .firmware_version =     1,
 412                 .identity =             DRIVER_NAME,
 413         };
 414
 415         switch (cmd) {
 416         case WDIOC_GETSUPPORT:
 417                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 418
 419         case WDIOC_GETSTATUS:
 420         case WDIOC_GETBOOTSTATUS:
 421                 return put_user(0, p);
 422
 423         case WDIOC_GETTEMP:
 424         {
 425                 int temperature;
 426
 427                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 428                         return -EFAULT;
 429
 430                 return put_user(temperature, p);
 431         }
 432
 433         case WDIOC_SETOPTIONS:
 434         {
 435                 int new_options, retval = -EINVAL;
 436
 437                 if (get_user(new_options, p))
 438                         return -EFAULT;
 439
 440                 if (new_options & WDIOS_DISABLECARD) {
 441                         usb_pcwd_stop(usb_pcwd_device);
 442                         retval = 0;
 443                 }
 444
 445                 if (new_options & WDIOS_ENABLECARD) {
 446                         usb_pcwd_start(usb_pcwd_device);
 447                         retval = 0;
 448                 }
 449
 450                 return retval;
 451         }
 452
 453         case WDIOC_KEEPALIVE:
 454                 usb_pcwd_keepalive(usb_pcwd_device);
 455                 return 0;
 456
 457         case WDIOC_SETTIMEOUT:
 458         {
 459                 int new_heartbeat;
 460
 461                 if (get_user(new_heartbeat, p))
 462                         return -EFAULT;
 463
 464                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 465                         return -EINVAL;
 466
 467                 usb_pcwd_keepalive(usb_pcwd_device);
 468                 /* Fall */
 469         }
 470
 471         case WDIOC_GETTIMEOUT:
 472                 return put_user(heartbeat, p);
 473
 474         case WDIOC_GETTIMELEFT:
 475         {
 476                 int time_left;
 477
 478                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 479                         return -EFAULT;
 480
 481                 return put_user(time_left, p);
 482         }
 483
 484         default:
 485                 return -ENOTTY;
 486         }
 487 }
 488
 489 static int usb_pcwd_open(struct inode *inode, struct file *file)
 490 {
 491         /* /dev/watchdog can only be opened once */
 492         if (test_and_set_bit(0, &is_active))
 493                 return -EBUSY;
 494
 495         /* Activate */
 496         usb_pcwd_start(usb_pcwd_device);
 497         usb_pcwd_keepalive(usb_pcwd_device);
 498         return nonseekable_open(inode, file);
 499 }
 500
 501 static int usb_pcwd_release(struct inode *inode, struct file *file)
 502 {
 503         /*
 504          *      Shut off the timer.
 505          */
 506         if (expect_release == 42) {
 507                 usb_pcwd_stop(usb_pcwd_device);
 508         } else {
 509                 printk(KERN_CRIT PFX
 510                         "Unexpected close, not stopping watchdog!\n");
 511                 usb_pcwd_keepalive(usb_pcwd_device);
 512         }
 513         expect_release = 0;
 514         clear_bit(0, &is_active);
 515         return 0;
 516 }
 517
 518 /*
 519  *      /dev/temperature handling
 520  */
 521
 522 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 523                                 size_t len, loff_t *ppos)
 524 {
 525         int temperature;
 526
 527         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 528                 return -EFAULT;
 529
 530         if (copy_to_user(data, &temperature, 1))
 531                 return -EFAULT;
 532
 533         return 1;
 534 }
 535
 536 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 537 {
 538         return nonseekable_open(inode, file);
 539 }
 540
 541 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 542 {
 543         return 0;
 544 }
 545
 546 /*
 547  *      Notify system
 548  */
 549
 550 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 551                                                                 void *unused)
 552 {
 553         if (code == SYS_DOWN || code == SYS_HALT)
 554                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 555
 556         return NOTIFY_DONE;
 557 }
 558
 559 /*
 560  *      Kernel Interfaces
 561  */
 562
 563 static const struct file_operations usb_pcwd_fops = {
 564         .owner =        THIS_MODULE,
 565         .llseek =       no_llseek,
 566         .write =        usb_pcwd_write,
 567         .unlocked_ioctl = usb_pcwd_ioctl,
 568         .open =         usb_pcwd_open,
 569         .release =      usb_pcwd_release,
 570 };
 571
 572 static struct miscdevice usb_pcwd_miscdev = {
 573         .minor =        WATCHDOG_MINOR,
 574         .name =         "watchdog",
 575         .fops =         &usb_pcwd_fops,
 576 };
 577
 578 static const struct file_operations usb_pcwd_temperature_fops = {
 579         .owner =        THIS_MODULE,
 580         .llseek =       no_llseek,
 581         .read =         usb_pcwd_temperature_read,
 582         .open =         usb_pcwd_temperature_open,
 583         .release =      usb_pcwd_temperature_release,
 584 };
 585
 586 static struct miscdevice usb_pcwd_temperature_miscdev = {
 587         .minor =        TEMP_MINOR,
 588         .name =         "temperature",
 589         .fops =         &usb_pcwd_temperature_fops,
 590 };
 591
 592 static struct notifier_block usb_pcwd_notifier = {
 593         .notifier_call =        usb_pcwd_notify_sys,
 594 };
 595
 596 /**
 597  *      usb_pcwd_delete
 598  */
 599 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 600 {
 601         usb_free_urb(usb_pcwd->intr_urb);
 602         if (usb_pcwd->intr_buffer != NULL)
 603                 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 604                                   usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 605         kfree(usb_pcwd);
 606 }
 607
 608 /**
 609  *      usb_pcwd_probe
 610  *
 611  *      Called by the usb core when a new device is connected that it thinks
 612  *      this driver might be interested in.
 613  */
 614 static int usb_pcwd_probe(struct usb_interface *interface,
 615                                                 const struct usb_device_id *id)
 616 {
 617         struct usb_device *udev = interface_to_usbdev(interface);
 618         struct usb_host_interface *iface_desc;
 619         struct usb_endpoint_descriptor *endpoint;
 620         struct usb_pcwd_private *usb_pcwd = NULL;
 621         int pipe, maxp;
 622         int retval = -ENOMEM;
 623         int got_fw_rev;
 624         unsigned char fw_rev_major, fw_rev_minor;
 625         char fw_ver_str[20];
 626         unsigned char option_switches, dummy;
 627
 628         cards_found++;
 629         if (cards_found > 1) {
 630                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 631                 return -ENODEV;
 632         }
 633
 634         /* get the active interface descriptor */
 635         iface_desc = interface->cur_altsetting;
 636
 637         /* check out that we have a HID device */
 638         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 639                 printk(KERN_ERR PFX
 640                         "The device isn't a Human Interface Device\n");
 641                 return -ENODEV;
 642         }
 643
 644         /* check out the endpoint: it has to be Interrupt & IN */
 645         endpoint = &iface_desc->endpoint[0].desc;
 646
 647         if (!usb_endpoint_is_int_in(endpoint)) {
 648                 /* we didn't find a Interrupt endpoint with direction IN */
 649                 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 650                 return -ENODEV;
 651         }
 652
 653         /* get a handle to the interrupt data pipe */
 654         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 655         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 656
 657         /* allocate memory for our device and initialize it */
 658         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 659         if (usb_pcwd == NULL) {
 660                 printk(KERN_ERR PFX "Out of memory\n");
 661                 goto error;
 662         }
 663
 664         usb_pcwd_device = usb_pcwd;
 665
 666         mutex_init(&usb_pcwd->mtx);
 667         usb_pcwd->udev = udev;
 668         usb_pcwd->interface = interface;
 669         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 670         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 671                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 672
 673         /* set up the memory buffer's */
 674         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 675                                         GFP_ATOMIC, &usb_pcwd->intr_dma);
 676         if (!usb_pcwd->intr_buffer) {
 677                 printk(KERN_ERR PFX "Out of memory\n");
 678                 goto error;
 679         }
 680
 681         /* allocate the urb's */
 682         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 683         if (!usb_pcwd->intr_urb) {
 684                 printk(KERN_ERR PFX "Out of memory\n");
 685                 goto error;
 686         }
 687
 688         /* initialise the intr urb's */
 689         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 690                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 691                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 692         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 693         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 694
 695         /* register our interrupt URB with the USB system */
 696         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 697                 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 698                 retval = -EIO; /* failure */
 699                 goto error;
 700         }
 701
 702         /* The device exists and can be communicated with */
 703         usb_pcwd->exists = 1;
 704
 705         /* disable card */
 706         usb_pcwd_stop(usb_pcwd);
 707
 708         /* Get the Firmware Version */
 709         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 710                                                 &fw_rev_major, &fw_rev_minor);
 711         if (got_fw_rev)
 712                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 713         else
 714                 sprintf(fw_ver_str, "<card no answer>");
 715
 716         printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 717                 fw_ver_str);
 718
 719         /* Get switch settings */
 720         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 721                                                         &option_switches);
 722
 723         printk(KERN_INFO PFX "Option switches (0x%02x): "
 724                 "Temperature Reset Enable=%s, Power On Delay=%s\n",
 725                 option_switches,
 726                 ((option_switches & 0x10) ? "ON" : "OFF"),
 727                 ((option_switches & 0x08) ? "ON" : "OFF"));
 728
 729         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 730         if (heartbeat == 0)
 731                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 732
 733         /* Check that the heartbeat value is within it's range ;
 734          * if not reset to the default */
 735         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 736                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 737                 printk(KERN_INFO PFX
 738                         "heartbeat value must be 0<heartbeat<65536, using %d\n",
 739                         WATCHDOG_HEARTBEAT);
 740         }
 741
 742         retval = register_reboot_notifier(&usb_pcwd_notifier);
 743         if (retval != 0) {
 744                 printk(KERN_ERR PFX
 745                         "cannot register reboot notifier (err=%d)\n",
 746                         retval);
 747                 goto error;
 748         }
 749
 750         retval = misc_register(&usb_pcwd_temperature_miscdev);
 751         if (retval != 0) {
 752                 printk(KERN_ERR PFX
 753                         "cannot register miscdev on minor=%d (err=%d)\n",
 754                         TEMP_MINOR, retval);
 755                 goto err_out_unregister_reboot;
 756         }
 757
 758         retval = misc_register(&usb_pcwd_miscdev);
 759         if (retval != 0) {
 760                 printk(KERN_ERR PFX
 761                         "cannot register miscdev on minor=%d (err=%d)\n",
 762                         WATCHDOG_MINOR, retval);
 763                 goto err_out_misc_deregister;
 764         }
 765
 766         /* we can register the device now, as it is ready */
 767         usb_set_intfdata(interface, usb_pcwd);
 768
 769         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 770                 heartbeat, nowayout);
 771
 772         return 0;
 773
 774 err_out_misc_deregister:
 775         misc_deregister(&usb_pcwd_temperature_miscdev);
 776 err_out_unregister_reboot:
 777         unregister_reboot_notifier(&usb_pcwd_notifier);
 778 error:
 779         if (usb_pcwd)
 780                 usb_pcwd_delete(usb_pcwd);
 781         usb_pcwd_device = NULL;
 782         return retval;
 783 }
 784
 785
 786 /**
 787  *      usb_pcwd_disconnect
 788  *
 789  *      Called by the usb core when the device is removed from the system.
 790  *
 791  *      This routine guarantees that the driver will not submit any more urbs
 792  *      by clearing dev->udev.
 793  */
 794 static void usb_pcwd_disconnect(struct usb_interface *interface)
 795 {
 796         struct usb_pcwd_private *usb_pcwd;
 797
 798         /* prevent races with open() */
 799         mutex_lock(&disconnect_mutex);
 800
 801         usb_pcwd = usb_get_intfdata(interface);
 802         usb_set_intfdata(interface, NULL);
 803
 804         mutex_lock(&usb_pcwd->mtx);
 805
 806         /* Stop the timer before we leave */
 807         if (!nowayout)
 808                 usb_pcwd_stop(usb_pcwd);
 809
 810         /* We should now stop communicating with the USB PCWD device */
 811         usb_pcwd->exists = 0;
 812
 813         /* Deregister */
 814         misc_deregister(&usb_pcwd_miscdev);
 815         misc_deregister(&usb_pcwd_temperature_miscdev);
 816         unregister_reboot_notifier(&usb_pcwd_notifier);
 817
 818         mutex_unlock(&usb_pcwd->mtx);
 819
 820         /* Delete the USB PCWD device */
 821         usb_pcwd_delete(usb_pcwd);
 822
 823         cards_found--;
 824
 825         mutex_unlock(&disconnect_mutex);
 826
 827         printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 828 }
 829
 830 module_usb_driver(usb_pcwd_driver);