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, sizeof(ident)) ? -EFAULT : 0;
 387
 388         case WDIOC_GETSTATUS:
 389         case WDIOC_GETBOOTSTATUS:
 390                 return put_user(0, p);
 391
 392         case WDIOC_GETTEMP:
 393         {
 394                 int temperature;
 395
 396                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 397                         return -EFAULT;
 398
 399                 return put_user(temperature, p);
 400         }
 401
 402         case WDIOC_SETOPTIONS:
 403         {
 404                 int new_options, retval = -EINVAL;
 405
 406                 if (get_user(new_options, p))
 407                         return -EFAULT;
 408
 409                 if (new_options & WDIOS_DISABLECARD) {
 410                         usb_pcwd_stop(usb_pcwd_device);
 411                         retval = 0;
 412                 }
 413
 414                 if (new_options & WDIOS_ENABLECARD) {
 415                         usb_pcwd_start(usb_pcwd_device);
 416                         retval = 0;
 417                 }
 418
 419                 return retval;
 420         }
 421
 422         case WDIOC_KEEPALIVE:
 423                 usb_pcwd_keepalive(usb_pcwd_device);
 424                 return 0;
 425
 426         case WDIOC_SETTIMEOUT:
 427         {
 428                 int new_heartbeat;
 429
 430                 if (get_user(new_heartbeat, p))
 431                         return -EFAULT;
 432
 433                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 434                     return -EINVAL;
 435
 436                 usb_pcwd_keepalive(usb_pcwd_device);
 437                 /* Fall */
 438         }
 439
 440         case WDIOC_GETTIMEOUT:
 441                 return put_user(heartbeat, p);
 442
 443         case WDIOC_GETTIMELEFT:
 444         {
 445                 int time_left;
 446
 447                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 448                         return -EFAULT;
 449
 450                 return put_user(time_left, p);
 451         }
 452
 453         default:
 454                 return -ENOTTY;
 455         }
 456 }
 457
 458 static int usb_pcwd_open(struct inode *inode, struct file *file)
 459 {
 460         /* /dev/watchdog can only be opened once */
 461         if (test_and_set_bit(0, &is_active))
 462                 return -EBUSY;
 463
 464         /* Activate */
 465         usb_pcwd_start(usb_pcwd_device);
 466         usb_pcwd_keepalive(usb_pcwd_device);
 467         return nonseekable_open(inode, file);
 468 }
 469
 470 static int usb_pcwd_release(struct inode *inode, struct file *file)
 471 {
 472         /*
 473          *      Shut off the timer.
 474          */
 475         if (expect_release == 42) {
 476                 usb_pcwd_stop(usb_pcwd_device);
 477         } else {
 478                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 479                 usb_pcwd_keepalive(usb_pcwd_device);
 480         }
 481         expect_release = 0;
 482         clear_bit(0, &is_active);
 483         return 0;
 484 }
 485
 486 /*
 487  *      /dev/temperature handling
 488  */
 489
 490 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 491                                 size_t len, loff_t *ppos)
 492 {
 493         int temperature;
 494
 495         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 496                 return -EFAULT;
 497
 498         if (copy_to_user(data, &temperature, 1))
 499                 return -EFAULT;
 500
 501         return 1;
 502 }
 503
 504 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 505 {
 506         return nonseekable_open(inode, file);
 507 }
 508
 509 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 510 {
 511         return 0;
 512 }
 513
 514 /*
 515  *      Notify system
 516  */
 517
 518 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 519 {
 520         if (code == SYS_DOWN || code == SYS_HALT)
 521                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 522
 523         return NOTIFY_DONE;
 524 }
 525
 526 /*
 527  *      Kernel Interfaces
 528  */
 529
 530 static const struct file_operations usb_pcwd_fops = {
 531         .owner =        THIS_MODULE,
 532         .llseek =       no_llseek,
 533         .write =        usb_pcwd_write,
 534         .unlocked_ioctl = usb_pcwd_ioctl,
 535         .open =         usb_pcwd_open,
 536         .release =      usb_pcwd_release,
 537 };
 538
 539 static struct miscdevice usb_pcwd_miscdev = {
 540         .minor =        WATCHDOG_MINOR,
 541         .name =         "watchdog",
 542         .fops =         &usb_pcwd_fops,
 543 };
 544
 545 static const struct file_operations usb_pcwd_temperature_fops = {
 546         .owner =        THIS_MODULE,
 547         .llseek =       no_llseek,
 548         .read =         usb_pcwd_temperature_read,
 549         .open =         usb_pcwd_temperature_open,
 550         .release =      usb_pcwd_temperature_release,
 551 };
 552
 553 static struct miscdevice usb_pcwd_temperature_miscdev = {
 554         .minor =        TEMP_MINOR,
 555         .name =         "temperature",
 556         .fops =         &usb_pcwd_temperature_fops,
 557 };
 558
 559 static struct notifier_block usb_pcwd_notifier = {
 560         .notifier_call =        usb_pcwd_notify_sys,
 561 };
 562
 563 /**
 564  *      usb_pcwd_delete
 565  */
 566 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 567 {
 568         usb_free_urb(usb_pcwd->intr_urb);
 569         if (usb_pcwd->intr_buffer != NULL)
 570                 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
 571                                 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 572         kfree(usb_pcwd);
 573 }
 574
 575 /**
 576  *      usb_pcwd_probe
 577  *
 578  *      Called by the usb core when a new device is connected that it thinks
 579  *      this driver might be interested in.
 580  */
 581 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
 582 {
 583         struct usb_device *udev = interface_to_usbdev(interface);
 584         struct usb_host_interface *iface_desc;
 585         struct usb_endpoint_descriptor *endpoint;
 586         struct usb_pcwd_private *usb_pcwd = NULL;
 587         int pipe, maxp;
 588         int retval = -ENOMEM;
 589         int got_fw_rev;
 590         unsigned char fw_rev_major, fw_rev_minor;
 591         char fw_ver_str[20];
 592         unsigned char option_switches, dummy;
 593
 594         cards_found++;
 595         if (cards_found > 1) {
 596                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 597                 return -ENODEV;
 598         }
 599
 600         /* get the active interface descriptor */
 601         iface_desc = interface->cur_altsetting;
 602
 603         /* check out that we have a HID device */
 604         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 605                 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
 606                 return -ENODEV;
 607         }
 608
 609         /* check out the endpoint: it has to be Interrupt & IN */
 610         endpoint = &iface_desc->endpoint[0].desc;
 611
 612         if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
 613              ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 614                                 == USB_ENDPOINT_XFER_INT))) {
 615                 /* we didn't find a Interrupt endpoint with direction IN */
 616                 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 617                 return -ENODEV;
 618         }
 619
 620         /* get a handle to the interrupt data pipe */
 621         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 622         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 623
 624         /* allocate memory for our device and initialize it */
 625         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 626         if (usb_pcwd == NULL) {
 627                 printk(KERN_ERR PFX "Out of memory\n");
 628                 goto error;
 629         }
 630
 631         usb_pcwd_device = usb_pcwd;
 632
 633         mutex_init(&usb_pcwd->mtx);
 634         usb_pcwd->udev = udev;
 635         usb_pcwd->interface = interface;
 636         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 637         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 638
 639         /* set up the memory buffer's */
 640         usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma);
 641         if (!usb_pcwd->intr_buffer) {
 642                 printk(KERN_ERR PFX "Out of memory\n");
 643                 goto error;
 644         }
 645
 646         /* allocate the urb's */
 647         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 648         if (!usb_pcwd->intr_urb) {
 649                 printk(KERN_ERR PFX "Out of memory\n");
 650                 goto error;
 651         }
 652
 653         /* initialise the intr urb's */
 654         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 655                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 656                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 657         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 658         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 659
 660         /* register our interrupt URB with the USB system */
 661         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 662                 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 663                 retval = -EIO; /* failure */
 664                 goto error;
 665         }
 666
 667         /* The device exists and can be communicated with */
 668         usb_pcwd->exists = 1;
 669
 670         /* disable card */
 671         usb_pcwd_stop(usb_pcwd);
 672
 673         /* Get the Firmware Version */
 674         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
 675         if (got_fw_rev)
 676                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 677         else
 678                 sprintf(fw_ver_str, "<card no answer>");
 679
 680         printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 681                 fw_ver_str);
 682
 683         /* Get switch settings */
 684         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
 685
 686         printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 687                 option_switches,
 688                 ((option_switches & 0x10) ? "ON" : "OFF"),
 689                 ((option_switches & 0x08) ? "ON" : "OFF"));
 690
 691         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 692         if (heartbeat == 0)
 693                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 694
 695         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 696         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 697                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 698                 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
 699                         WATCHDOG_HEARTBEAT);
 700         }
 701
 702         retval = register_reboot_notifier(&usb_pcwd_notifier);
 703         if (retval != 0) {
 704                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 705                         retval);
 706                 goto error;
 707         }
 708
 709         retval = misc_register(&usb_pcwd_temperature_miscdev);
 710         if (retval != 0) {
 711                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 712                         TEMP_MINOR, retval);
 713                 goto err_out_unregister_reboot;
 714         }
 715
 716         retval = misc_register(&usb_pcwd_miscdev);
 717         if (retval != 0) {
 718                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 719                         WATCHDOG_MINOR, retval);
 720                 goto err_out_misc_deregister;
 721         }
 722
 723         /* we can register the device now, as it is ready */
 724         usb_set_intfdata(interface, usb_pcwd);
 725
 726         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 727                 heartbeat, nowayout);
 728
 729         return 0;
 730
 731 err_out_misc_deregister:
 732         misc_deregister(&usb_pcwd_temperature_miscdev);
 733 err_out_unregister_reboot:
 734         unregister_reboot_notifier(&usb_pcwd_notifier);
 735 error:
 736         if (usb_pcwd)
 737                 usb_pcwd_delete(usb_pcwd);
 738         usb_pcwd_device = NULL;
 739         return retval;
 740 }
 741
 742
 743 /**
 744  *      usb_pcwd_disconnect
 745  *
 746  *      Called by the usb core when the device is removed from the system.
 747  *
 748  *      This routine guarantees that the driver will not submit any more urbs
 749  *      by clearing dev->udev.
 750  */
 751 static void usb_pcwd_disconnect(struct usb_interface *interface)
 752 {
 753         struct usb_pcwd_private *usb_pcwd;
 754
 755         /* prevent races with open() */
 756         mutex_lock(&disconnect_mutex);
 757
 758         usb_pcwd = usb_get_intfdata(interface);
 759         usb_set_intfdata(interface, NULL);
 760
 761         mutex_lock(&usb_pcwd->mtx);
 762
 763         /* Stop the timer before we leave */
 764         if (!nowayout)
 765                 usb_pcwd_stop(usb_pcwd);
 766
 767         /* We should now stop communicating with the USB PCWD device */
 768         usb_pcwd->exists = 0;
 769
 770         /* Deregister */
 771         misc_deregister(&usb_pcwd_miscdev);
 772         misc_deregister(&usb_pcwd_temperature_miscdev);
 773         unregister_reboot_notifier(&usb_pcwd_notifier);
 774
 775         mutex_unlock(&usb_pcwd->mtx);
 776
 777         /* Delete the USB PCWD device */
 778         usb_pcwd_delete(usb_pcwd);
 779
 780         cards_found--;
 781
 782         mutex_unlock(&disconnect_mutex);
 783
 784         printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 785 }
 786
 787
 788
 789 /**
 790  *      usb_pcwd_init
 791  */
 792 static int __init usb_pcwd_init(void)
 793 {
 794         int result;
 795
 796         /* register this driver with the USB subsystem */
 797         result = usb_register(&usb_pcwd_driver);
 798         if (result) {
 799                 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
 800                     result);
 801                 return result;
 802         }
 803
 804         printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
 805         return 0;
 806 }
 807
 808
 809 /**
 810  *      usb_pcwd_exit
 811  */
 812 static void __exit usb_pcwd_exit(void)
 813 {
 814         /* deregister this driver with the USB subsystem */
 815         usb_deregister(&usb_pcwd_driver);
 816 }
 817
 818
 819 module_init(usb_pcwd_init);
 820 module_exit(usb_pcwd_exit);