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