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