drivers/char/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004 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/config.h>
  28 #include <linux/kernel.h>
  29 #include <linux/errno.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/types.h>
  35 #include <linux/delay.h>
  36 #include <linux/miscdevice.h>
  37 #include <linux/watchdog.h>
  38 #include <linux/notifier.h>
  39 #include <linux/reboot.h>
  40 #include <linux/fs.h>
  41 #include <linux/smp_lock.h>
  42 #include <linux/completion.h>
  43 #include <asm/uaccess.h>
  44 #include <linux/usb.h>
  45
  46
  47 #ifdef CONFIG_USB_DEBUG
  48         static int debug = 1;
  49 #else
  50         static int debug;
  51 #endif
  52
  53 /* Use our own dbg macro */
  54 #undef dbg
  55 #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
  56
  57
  58 /* Module and Version Information */
  59 #define DRIVER_VERSION "1.01"
  60 #define DRIVER_DATE "15 Mar 2005"
  61 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  62 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  63 #define DRIVER_LICENSE "GPL"
  64 #define DRIVER_NAME "pcwd_usb"
  65 #define PFX DRIVER_NAME ": "
  66
  67 MODULE_AUTHOR(DRIVER_AUTHOR);
  68 MODULE_DESCRIPTION(DRIVER_DESC);
  69 MODULE_LICENSE(DRIVER_LICENSE);
  70 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
  71 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
  72
  73 /* Module Parameters */
  74 module_param(debug, int, 0);
  75 MODULE_PARM_DESC(debug, "Debug enabled or not");
  76
  77 #define WATCHDOG_HEARTBEAT 2    /* 2 sec default heartbeat */
  78 static int heartbeat = WATCHDOG_HEARTBEAT;
  79 module_param(heartbeat, int, 0);
  80 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  81
  82 #ifdef CONFIG_WATCHDOG_NOWAYOUT
  83 static int nowayout = 1;
  84 #else
  85 static int nowayout = 0;
  86 #endif
  87
  88 module_param(nowayout, int, 0);
  89 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
  90
  91 /* The vendor and product id's for the USB-PC Watchdog card */
  92 #define USB_PCWD_VENDOR_ID      0x0c98
  93 #define USB_PCWD_PRODUCT_ID     0x1140
  94
  95 /* table of devices that work with this driver */
  96 static struct usb_device_id usb_pcwd_table [] = {
  97         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  98         { }                                     /* Terminating entry */
  99 };
 100 MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
 101
 102 /* according to documentation max. time to process a command for the USB
 103  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
 104 #define USB_COMMAND_TIMEOUT     250
 105
 106 /* Watchdog's internal commands */
 107 #define CMD_READ_TEMP                   0x02    /* Read Temperature; Re-trigger Watchdog */
 108 #define CMD_TRIGGER                     CMD_READ_TEMP
 109 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 110 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 111 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 112 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 113 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current Watchdog Time */
 114 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 115 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 116
 117 /* Some defines that I like to be somewhere else like include/linux/usb_hid.h */
 118 #define HID_REQ_SET_REPORT              0x09
 119 #define HID_DT_REPORT                   (USB_TYPE_CLASS | 0x02)
 120
 121 /* We can only use 1 card due to the /dev/watchdog restriction */
 122 static int cards_found;
 123
 124 /* some internal variables */
 125 static unsigned long is_active;
 126 static char expect_release;
 127
 128 /* Structure to hold all of our device specific stuff */
 129 struct usb_pcwd_private {
 130         struct usb_device *     udev;                   /* save off the usb device pointer */
 131         struct usb_interface *  interface;              /* the interface for this device */
 132
 133         unsigned int            interface_number;       /* the interface number used for cmd's */
 134
 135         unsigned char *         intr_buffer;            /* the buffer to intr data */
 136         dma_addr_t              intr_dma;               /* the dma address for the intr buffer */
 137         size_t                  intr_size;              /* the size of the intr buffer */
 138         struct urb *            intr_urb;               /* the urb used for the intr pipe */
 139
 140         unsigned char           cmd_command;            /* The command that is reported back */
 141         unsigned char           cmd_data_msb;           /* The data MSB that is reported back */
 142         unsigned char           cmd_data_lsb;           /* The data LSB that is reported back */
 143         atomic_t                cmd_received;           /* true if we received a report after a command */
 144
 145         int                     exists;                 /* Wether or not the device exists */
 146         struct semaphore        sem;                    /* locks this structure */
 147 };
 148 static struct usb_pcwd_private *usb_pcwd_device;
 149
 150 /* prevent races between open() and disconnect() */
 151 static DECLARE_MUTEX (disconnect_sem);
 152
 153 /* local function prototypes */
 154 static int usb_pcwd_probe       (struct usb_interface *interface, const struct usb_device_id *id);
 155 static void usb_pcwd_disconnect (struct usb_interface *interface);
 156
 157 /* usb specific object needed to register this driver with the usb subsystem */
 158 static struct usb_driver usb_pcwd_driver = {
 159         .owner =        THIS_MODULE,
 160         .name =         DRIVER_NAME,
 161         .probe =        usb_pcwd_probe,
 162         .disconnect =   usb_pcwd_disconnect,
 163         .id_table =     usb_pcwd_table,
 164 };
 165
 166
 167 static void usb_pcwd_intr_done(struct urb *urb, struct pt_regs *regs)
 168 {
 169         struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
 170         unsigned char *data = usb_pcwd->intr_buffer;
 171         int retval;
 172
 173         switch (urb->status) {
 174         case 0:                 /* success */
 175                 break;
 176         case -ECONNRESET:       /* unlink */
 177         case -ENOENT:
 178         case -ESHUTDOWN:
 179                 /* this urb is terminated, clean up */
 180                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
 181                 return;
 182         /* -EPIPE:  should clear the halt */
 183         default:                /* error */
 184                 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
 185                 goto resubmit;
 186         }
 187
 188         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 189                 data[0], data[1], data[2]);
 190
 191         usb_pcwd->cmd_command  = data[0];
 192         usb_pcwd->cmd_data_msb = data[1];
 193         usb_pcwd->cmd_data_lsb = data[2];
 194
 195         /* notify anyone waiting that the cmd has finished */
 196         atomic_set (&usb_pcwd->cmd_received, 1);
 197
 198 resubmit:
 199         retval = usb_submit_urb (urb, GFP_ATOMIC);
 200         if (retval)
 201                 printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
 202                         retval);
 203 }
 204
 205 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
 206         unsigned char *msb, unsigned char *lsb)
 207 {
 208         int got_response, count;
 209         unsigned char buf[6];
 210
 211         /* We will not send any commands if the USB PCWD device does not exist */
 212         if ((!usb_pcwd) || (!usb_pcwd->exists))
 213                 return -1;
 214
 215         /* The USB PC Watchdog uses a 6 byte report format. The board currently uses
 216          * only 3 of the six bytes of the report. */
 217         buf[0] = cmd;                   /* Byte 0 = CMD */
 218         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 219         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 220         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 221
 222         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 223                 buf[0], buf[1], buf[2]);
 224
 225         atomic_set (&usb_pcwd->cmd_received, 0);
 226
 227         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 228                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 229                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 230                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 231                 dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 232         }
 233         /* wait till the usb card processed the command,
 234          * with a max. timeout of USB_COMMAND_TIMEOUT */
 235         got_response = 0;
 236         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
 237                 mdelay(1);
 238                 if (atomic_read (&usb_pcwd->cmd_received))
 239                         got_response = 1;
 240         }
 241
 242         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 243                 /* read back response */
 244                 *msb = usb_pcwd->cmd_data_msb;
 245                 *lsb = usb_pcwd->cmd_data_lsb;
 246         }
 247
 248         return got_response;
 249 }
 250
 251 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 252 {
 253         unsigned char msb = 0x00;
 254         unsigned char lsb = 0x00;
 255         int retval;
 256
 257         /* Enable Watchdog */
 258         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
 259
 260         if ((retval == 0) || (lsb == 0)) {
 261                 printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
 262                 return -1;
 263         }
 264
 265         return 0;
 266 }
 267
 268 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 269 {
 270         unsigned char msb = 0xA5;
 271         unsigned char lsb = 0xC3;
 272         int retval;
 273
 274         /* Disable Watchdog */
 275         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
 276
 277         if ((retval == 0) || (lsb != 0)) {
 278                 printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
 279                 return -1;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 286 {
 287         unsigned char dummy;
 288
 289         /* Re-trigger Watchdog */
 290         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 291
 292         return 0;
 293 }
 294
 295 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 296 {
 297         unsigned char msb = t / 256;
 298         unsigned char lsb = t % 256;
 299
 300         if ((t < 0x0001) || (t > 0xFFFF))
 301                 return -EINVAL;
 302
 303         /* Write new heartbeat to watchdog */
 304         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 305
 306         heartbeat = t;
 307         return 0;
 308 }
 309
 310 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
 311 {
 312         unsigned char msb, lsb;
 313
 314         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 315
 316         /*
 317          * Convert celsius to fahrenheit, since this was
 318          * the decided 'standard' for this return value.
 319          */
 320         *temperature = (lsb * 9 / 5) + 32;
 321
 322         return 0;
 323 }
 324
 325 /*
 326  *      /dev/watchdog handling
 327  */
 328
 329 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 330                               size_t len, loff_t *ppos)
 331 {
 332         /* See if we got the magic character 'V' and reload the timer */
 333         if (len) {
 334                 if (!nowayout) {
 335                         size_t i;
 336
 337                         /* note: just in case someone wrote the magic character
 338                          * five months ago... */
 339                         expect_release = 0;
 340
 341                         /* scan to see whether or not we got the magic character */
 342                         for (i = 0; i != len; i++) {
 343                                 char c;
 344                                 if(get_user(c, data+i))
 345                                         return -EFAULT;
 346                                 if (c == 'V')
 347                                         expect_release = 42;
 348                         }
 349                 }
 350
 351                 /* someone wrote to us, we should reload the timer */
 352                 usb_pcwd_keepalive(usb_pcwd_device);
 353         }
 354         return len;
 355 }
 356
 357 static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
 358                           unsigned int cmd, unsigned long arg)
 359 {
 360         void __user *argp = (void __user *)arg;
 361         int __user *p = argp;
 362         static struct watchdog_info ident = {
 363                 .options =              WDIOF_KEEPALIVEPING |
 364                                         WDIOF_SETTIMEOUT |
 365                                         WDIOF_MAGICCLOSE,
 366                 .firmware_version =     1,
 367                 .identity =             DRIVER_NAME,
 368         };
 369
 370         switch (cmd) {
 371                 case WDIOC_GETSUPPORT:
 372                         return copy_to_user(argp, &ident,
 373                                 sizeof (ident)) ? -EFAULT : 0;
 374
 375                 case WDIOC_GETSTATUS:
 376                 case WDIOC_GETBOOTSTATUS:
 377                         return put_user(0, p);
 378
 379                 case WDIOC_GETTEMP:
 380                 {
 381                         int temperature;
 382
 383                         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 384                                 return -EFAULT;
 385
 386                         return put_user(temperature, p);
 387                 }
 388
 389                 case WDIOC_KEEPALIVE:
 390                         usb_pcwd_keepalive(usb_pcwd_device);
 391                         return 0;
 392
 393                 case WDIOC_SETOPTIONS:
 394                 {
 395                         int new_options, retval = -EINVAL;
 396
 397                         if (get_user (new_options, p))
 398                                 return -EFAULT;
 399
 400                         if (new_options & WDIOS_DISABLECARD) {
 401                                 usb_pcwd_stop(usb_pcwd_device);
 402                                 retval = 0;
 403                         }
 404
 405                         if (new_options & WDIOS_ENABLECARD) {
 406                                 usb_pcwd_start(usb_pcwd_device);
 407                                 retval = 0;
 408                         }
 409
 410                         return retval;
 411                 }
 412
 413                 case WDIOC_SETTIMEOUT:
 414                 {
 415                         int new_heartbeat;
 416
 417                         if (get_user(new_heartbeat, p))
 418                                 return -EFAULT;
 419
 420                         if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 421                             return -EINVAL;
 422
 423                         usb_pcwd_keepalive(usb_pcwd_device);
 424                         /* Fall */
 425                 }
 426
 427                 case WDIOC_GETTIMEOUT:
 428                         return put_user(heartbeat, p);
 429
 430                 default:
 431                         return -ENOIOCTLCMD;
 432         }
 433 }
 434
 435 static int usb_pcwd_open(struct inode *inode, struct file *file)
 436 {
 437         /* /dev/watchdog can only be opened once */
 438         if (test_and_set_bit(0, &is_active))
 439                 return -EBUSY;
 440
 441         /* Activate */
 442         usb_pcwd_start(usb_pcwd_device);
 443         usb_pcwd_keepalive(usb_pcwd_device);
 444         return nonseekable_open(inode, file);
 445 }
 446
 447 static int usb_pcwd_release(struct inode *inode, struct file *file)
 448 {
 449         /*
 450          *      Shut off the timer.
 451          */
 452         if (expect_release == 42) {
 453                 usb_pcwd_stop(usb_pcwd_device);
 454         } else {
 455                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 456                 usb_pcwd_keepalive(usb_pcwd_device);
 457         }
 458         expect_release = 0;
 459         clear_bit(0, &is_active);
 460         return 0;
 461 }
 462
 463 /*
 464  *      /dev/temperature handling
 465  */
 466
 467 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 468                                 size_t len, loff_t *ppos)
 469 {
 470         int temperature;
 471
 472         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 473                 return -EFAULT;
 474
 475         if (copy_to_user(data, &temperature, 1))
 476                 return -EFAULT;
 477
 478         return 1;
 479 }
 480
 481 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 482 {
 483         return nonseekable_open(inode, file);
 484 }
 485
 486 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 487 {
 488         return 0;
 489 }
 490
 491 /*
 492  *      Notify system
 493  */
 494
 495 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 496 {
 497         if (code==SYS_DOWN || code==SYS_HALT) {
 498                 /* Turn the WDT off */
 499                 usb_pcwd_stop(usb_pcwd_device);
 500         }
 501
 502         return NOTIFY_DONE;
 503 }
 504
 505 /*
 506  *      Kernel Interfaces
 507  */
 508
 509 static struct file_operations usb_pcwd_fops = {
 510         .owner =        THIS_MODULE,
 511         .llseek =       no_llseek,
 512         .write =        usb_pcwd_write,
 513         .ioctl =        usb_pcwd_ioctl,
 514         .open =         usb_pcwd_open,
 515         .release =      usb_pcwd_release,
 516 };
 517
 518 static struct miscdevice usb_pcwd_miscdev = {
 519         .minor =        WATCHDOG_MINOR,
 520         .name =         "watchdog",
 521         .fops =         &usb_pcwd_fops,
 522 };
 523
 524 static struct file_operations usb_pcwd_temperature_fops = {
 525         .owner =        THIS_MODULE,
 526         .llseek =       no_llseek,
 527         .read =         usb_pcwd_temperature_read,
 528         .open =         usb_pcwd_temperature_open,
 529         .release =      usb_pcwd_temperature_release,
 530 };
 531
 532 static struct miscdevice usb_pcwd_temperature_miscdev = {
 533         .minor =        TEMP_MINOR,
 534         .name =         "temperature",
 535         .fops =         &usb_pcwd_temperature_fops,
 536 };
 537
 538 static struct notifier_block usb_pcwd_notifier = {
 539         .notifier_call =        usb_pcwd_notify_sys,
 540 };
 541
 542 /**
 543  *      usb_pcwd_delete
 544  */
 545 static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
 546 {
 547         if (usb_pcwd->intr_urb != NULL)
 548                 usb_free_urb (usb_pcwd->intr_urb);
 549         if (usb_pcwd->intr_buffer != NULL)
 550                 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
 551                                 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 552         kfree (usb_pcwd);
 553 }
 554
 555 /**
 556  *      usb_pcwd_probe
 557  *
 558  *      Called by the usb core when a new device is connected that it thinks
 559  *      this driver might be interested in.
 560  */
 561 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
 562 {
 563         struct usb_device *udev = interface_to_usbdev(interface);
 564         struct usb_host_interface *iface_desc;
 565         struct usb_endpoint_descriptor *endpoint;
 566         struct usb_pcwd_private *usb_pcwd = NULL;
 567         int pipe, maxp;
 568         int retval = -ENOMEM;
 569         int got_fw_rev;
 570         unsigned char fw_rev_major, fw_rev_minor;
 571         char fw_ver_str[20];
 572         unsigned char option_switches, dummy;
 573
 574         cards_found++;
 575         if (cards_found > 1) {
 576                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 577                 return -ENODEV;
 578         }
 579
 580         /* get the active interface descriptor */
 581         iface_desc = interface->cur_altsetting;
 582
 583         /* check out that we have a HID device */
 584         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 585                 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
 586                 return -ENODEV;
 587         }
 588
 589         /* check out the endpoint: it has to be Interrupt & IN */
 590         endpoint = &iface_desc->endpoint[0].desc;
 591
 592         if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
 593              ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 594                                 == USB_ENDPOINT_XFER_INT))) {
 595                 /* we didn't find a Interrupt endpoint with direction IN */
 596                 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 597                 return -ENODEV;
 598         }
 599
 600         /* get a handle to the interrupt data pipe */
 601         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 602         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 603
 604         /* allocate memory for our device and initialize it */
 605         usb_pcwd = kmalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
 606         if (usb_pcwd == NULL) {
 607                 printk(KERN_ERR PFX "Out of memory\n");
 608                 goto error;
 609         }
 610         memset (usb_pcwd, 0x00, sizeof (*usb_pcwd));
 611
 612         usb_pcwd_device = usb_pcwd;
 613
 614         init_MUTEX (&usb_pcwd->sem);
 615         usb_pcwd->udev = udev;
 616         usb_pcwd->interface = interface;
 617         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 618         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 619
 620         /* set up the memory buffer's */
 621         if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, SLAB_ATOMIC, &usb_pcwd->intr_dma))) {
 622                 printk(KERN_ERR PFX "Out of memory\n");
 623                 goto error;
 624         }
 625
 626         /* allocate the urb's */
 627         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 628         if (!usb_pcwd->intr_urb) {
 629                 printk(KERN_ERR PFX "Out of memory\n");
 630                 goto error;
 631         }
 632
 633         /* initialise the intr urb's */
 634         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 635                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 636                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 637         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 638         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 639
 640         /* register our interrupt URB with the USB system */
 641         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 642                 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 643                 retval = -EIO; /* failure */
 644                 goto error;
 645         }
 646
 647         /* The device exists and can be communicated with */
 648         usb_pcwd->exists = 1;
 649
 650         /* disable card */
 651         usb_pcwd_stop(usb_pcwd);
 652
 653         /* Get the Firmware Version */
 654         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
 655         if (got_fw_rev) {
 656                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 657         } else {
 658                 sprintf(fw_ver_str, "<card no answer>");
 659         }
 660
 661         printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 662                 fw_ver_str);
 663
 664         /* Get switch settings */
 665         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
 666
 667         printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 668                 option_switches,
 669                 ((option_switches & 0x10) ? "ON" : "OFF"),
 670                 ((option_switches & 0x08) ? "ON" : "OFF"));
 671
 672         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 673         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 674                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 675                 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
 676                         WATCHDOG_HEARTBEAT);
 677         }
 678
 679         retval = register_reboot_notifier(&usb_pcwd_notifier);
 680         if (retval != 0) {
 681                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 682                         retval);
 683                 goto error;
 684         }
 685
 686         retval = misc_register(&usb_pcwd_temperature_miscdev);
 687         if (retval != 0) {
 688                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 689                         TEMP_MINOR, retval);
 690                 goto err_out_unregister_reboot;
 691         }
 692
 693         retval = misc_register(&usb_pcwd_miscdev);
 694         if (retval != 0) {
 695                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 696                         WATCHDOG_MINOR, retval);
 697                 goto err_out_misc_deregister;
 698         }
 699
 700         /* we can register the device now, as it is ready */
 701         usb_set_intfdata (interface, usb_pcwd);
 702
 703         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 704                 heartbeat, nowayout);
 705
 706         return 0;
 707
 708 err_out_misc_deregister:
 709         misc_deregister(&usb_pcwd_temperature_miscdev);
 710 err_out_unregister_reboot:
 711         unregister_reboot_notifier(&usb_pcwd_notifier);
 712 error:
 713         usb_pcwd_delete (usb_pcwd);
 714         usb_pcwd_device = NULL;
 715         return retval;
 716 }
 717
 718
 719 /**
 720  *      usb_pcwd_disconnect
 721  *
 722  *      Called by the usb core when the device is removed from the system.
 723  *
 724  *      This routine guarantees that the driver will not submit any more urbs
 725  *      by clearing dev->udev.
 726  */
 727 static void usb_pcwd_disconnect(struct usb_interface *interface)
 728 {
 729         struct usb_pcwd_private *usb_pcwd;
 730
 731         /* prevent races with open() */
 732         down (&disconnect_sem);
 733
 734         usb_pcwd = usb_get_intfdata (interface);
 735         usb_set_intfdata (interface, NULL);
 736
 737         down (&usb_pcwd->sem);
 738
 739         /* Stop the timer before we leave */
 740         if (!nowayout)
 741                 usb_pcwd_stop(usb_pcwd);
 742
 743         /* We should now stop communicating with the USB PCWD device */
 744         usb_pcwd->exists = 0;
 745
 746         /* Deregister */
 747         misc_deregister(&usb_pcwd_miscdev);
 748         misc_deregister(&usb_pcwd_temperature_miscdev);
 749         unregister_reboot_notifier(&usb_pcwd_notifier);
 750
 751         up (&usb_pcwd->sem);
 752
 753         /* Delete the USB PCWD device */
 754         usb_pcwd_delete(usb_pcwd);
 755
 756         cards_found--;
 757
 758         up (&disconnect_sem);
 759
 760         printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 761 }
 762
 763
 764
 765 /**
 766  *      usb_pcwd_init
 767  */
 768 static int __init usb_pcwd_init(void)
 769 {
 770         int result;
 771
 772         /* register this driver with the USB subsystem */
 773         result = usb_register(&usb_pcwd_driver);
 774         if (result) {
 775                 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
 776                     result);
 777                 return result;
 778         }
 779
 780         printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
 781         return 0;
 782 }
 783
 784
 785 /**
 786  *      usb_pcwd_exit
 787  */
 788 static void __exit usb_pcwd_exit(void)
 789 {
 790         /* deregister this driver with the USB subsystem */
 791         usb_deregister(&usb_pcwd_driver);
 792 }
 793
 794
 795 module_init (usb_pcwd_init);
 796 module_exit (usb_pcwd_exit);