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