drivers/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      Based on source code of the following authors:
   7  *        Ken Hollis <kenji@bitgate.com>,
   8  *        Alan Cox <alan@redhat.com>,
   9  *        Matt Domsch <Matt_Domsch@dell.com>,
  10  *        Rob Radez <rob@osinvestor.com>,
  11  *        Greg Kroah-Hartman <greg@kroah.com>
  12  *
  13  *      This program is free software; you can redistribute it and/or
  14  *      modify it under the terms of the GNU General Public License
  15  *      as published by the Free Software Foundation; either version
  16  *      2 of the License, or (at your option) any later version.
  17  *
  18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  19  *      provide warranty for any of this software. This material is
  20  *      provided "AS-IS" and at no charge.
  21  *
  22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  23  *      providing the test hardware. More info is available at
  24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  25  */
  26
  27 #include <linux/module.h>       /* For module specific items */
  28 #include <linux/moduleparam.h>  /* For new moduleparam's */
  29 #include <linux/types.h>        /* For standard types (like size_t) */
  30 #include <linux/errno.h>        /* For the -ENODEV/... values */
  31 #include <linux/kernel.h>       /* For printk/panic/... */
  32 #include <linux/delay.h>        /* For mdelay function */
  33 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  34 #include <linux/watchdog.h>     /* For the watchdog specific items */
  35 #include <linux/notifier.h>     /* For notifier support */
  36 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  37 #include <linux/init.h>         /* For __init/__exit/... */
  38 #include <linux/fs.h>           /* For file operations */
  39 #include <linux/usb.h>          /* For USB functions */
  40 #include <linux/slab.h>         /* For kmalloc, ... */
  41 #include <linux/mutex.h>        /* For mutex locking */
  42 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  43
  44 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  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 "1.02"
  60 #define DRIVER_DATE "21 Jan 2007"
  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 0    /* default heartbeat = delay-time from dip-switches */
  78 static int heartbeat = WATCHDOG_HEARTBEAT;
  79 module_param(heartbeat, int, 0);
  80 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  81
  82 static int nowayout = WATCHDOG_NOWAYOUT;
  83 module_param(nowayout, int, 0);
  84 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  85
  86 /* The vendor and product id's for the USB-PC Watchdog card */
  87 #define USB_PCWD_VENDOR_ID      0x0c98
  88 #define USB_PCWD_PRODUCT_ID     0x1140
  89
  90 /* table of devices that work with this driver */
  91 static struct usb_device_id usb_pcwd_table [] = {
  92         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  93         { }                                     /* Terminating entry */
  94 };
  95 MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
  96
  97 /* according to documentation max. time to process a command for the USB
  98  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
  99 #define USB_COMMAND_TIMEOUT     250
 100
 101 /* Watchdog's internal commands */
 102 #define CMD_READ_TEMP                   0x02    /* Read Temperature; Re-trigger Watchdog */
 103 #define CMD_TRIGGER                     CMD_READ_TEMP
 104 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 105 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 106 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 107 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 108 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current Watchdog Time */
 109 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 110 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 111
 112 /* Watchdog's Dip Switch heartbeat values */
 113 static const int heartbeat_tbl [] = {
 114         5,      /* OFF-OFF-OFF  =  5 Sec  */
 115         10,     /* OFF-OFF-ON   = 10 Sec  */
 116         30,     /* OFF-ON-OFF   = 30 Sec  */
 117         60,     /* OFF-ON-ON    =  1 Min  */
 118         300,    /* ON-OFF-OFF   =  5 Min  */
 119         600,    /* ON-OFF-ON    = 10 Min  */
 120         1800,   /* ON-ON-OFF    = 30 Min  */
 121         3600,   /* ON-ON-ON     =  1 hour */
 122 };
 123
 124 /* We can only use 1 card due to the /dev/watchdog restriction */
 125 static int cards_found;
 126
 127 /* some internal variables */
 128 static unsigned long is_active;
 129 static char expect_release;
 130
 131 /* Structure to hold all of our device specific stuff */
 132 struct usb_pcwd_private {
 133         struct usb_device *     udev;                   /* save off the usb device pointer */
 134         struct usb_interface *  interface;              /* the interface for this device */
 135
 136         unsigned int            interface_number;       /* the interface number used for cmd's */
 137
 138         unsigned char *         intr_buffer;            /* the buffer to intr data */
 139         dma_addr_t              intr_dma;               /* the dma address for the intr buffer */
 140         size_t                  intr_size;              /* the size of the intr buffer */
 141         struct urb *            intr_urb;               /* the urb used for the intr pipe */
 142
 143         unsigned char           cmd_command;            /* The command that is reported back */
 144         unsigned char           cmd_data_msb;           /* The data MSB that is reported back */
 145         unsigned char           cmd_data_lsb;           /* The data LSB that is reported back */
 146         atomic_t                cmd_received;           /* true if we received a report after a command */
 147
 148         int                     exists;                 /* Wether or not the device exists */
 149         struct mutex            mtx;                    /* locks this structure */
 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, 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 = (struct usb_pcwd_private *)urb->context;
 172         unsigned char *data = usb_pcwd->intr_buffer;
 173         int retval;
 174
 175         switch (urb->status) {
 176         case 0:                 /* success */
 177                 break;
 178         case -ECONNRESET:       /* unlink */
 179         case -ENOENT:
 180         case -ESHUTDOWN:
 181                 /* this urb is terminated, clean up */
 182                 dbg("%s - urb shutting down with status: %d", __func__, urb->status);
 183                 return;
 184         /* -EPIPE:  should clear the halt */
 185         default:                /* error */
 186                 dbg("%s - nonzero urb status received: %d", __func__, urb->status);
 187                 goto resubmit;
 188         }
 189
 190         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 191                 data[0], data[1], data[2]);
 192
 193         usb_pcwd->cmd_command  = data[0];
 194         usb_pcwd->cmd_data_msb = data[1];
 195         usb_pcwd->cmd_data_lsb = data[2];
 196
 197         /* notify anyone waiting that the cmd has finished */
 198         atomic_set (&usb_pcwd->cmd_received, 1);
 199
 200 resubmit:
 201         retval = usb_submit_urb (urb, GFP_ATOMIC);
 202         if (retval)
 203                 printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
 204                         retval);
 205 }
 206
 207 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
 208         unsigned char *msb, unsigned char *lsb)
 209 {
 210         int got_response, count;
 211         unsigned char buf[6];
 212
 213         /* We will not send any commands if the USB PCWD device does not exist */
 214         if ((!usb_pcwd) || (!usb_pcwd->exists))
 215                 return -1;
 216
 217         /* The USB PC Watchdog uses a 6 byte report format. The board currently uses
 218          * only 3 of the six bytes of the report. */
 219         buf[0] = cmd;                   /* Byte 0 = CMD */
 220         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 221         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 222         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 223
 224         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 225                 buf[0], buf[1], buf[2]);
 226
 227         atomic_set (&usb_pcwd->cmd_received, 0);
 228
 229         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 230                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 231                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 232                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 233                 dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 234         }
 235         /* wait till the usb card processed the command,
 236          * with a max. timeout of USB_COMMAND_TIMEOUT */
 237         got_response = 0;
 238         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
 239                 mdelay(1);
 240                 if (atomic_read (&usb_pcwd->cmd_received))
 241                         got_response = 1;
 242         }
 243
 244         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 245                 /* read back response */
 246                 *msb = usb_pcwd->cmd_data_msb;
 247                 *lsb = usb_pcwd->cmd_data_lsb;
 248         }
 249
 250         return got_response;
 251 }
 252
 253 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 254 {
 255         unsigned char msb = 0x00;
 256         unsigned char lsb = 0x00;
 257         int retval;
 258
 259         /* Enable Watchdog */
 260         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
 261
 262         if ((retval == 0) || (lsb == 0)) {
 263                 printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
 264                 return -1;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 271 {
 272         unsigned char msb = 0xA5;
 273         unsigned char lsb = 0xC3;
 274         int retval;
 275
 276         /* Disable Watchdog */
 277         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
 278
 279         if ((retval == 0) || (lsb != 0)) {
 280                 printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
 281                 return -1;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 288 {
 289         unsigned char dummy;
 290
 291         /* Re-trigger Watchdog */
 292         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 293
 294         return 0;
 295 }
 296
 297 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 298 {
 299         unsigned char msb = t / 256;
 300         unsigned char lsb = t % 256;
 301
 302         if ((t < 0x0001) || (t > 0xFFFF))
 303                 return -EINVAL;
 304
 305         /* Write new heartbeat to watchdog */
 306         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 307
 308         heartbeat = t;
 309         return 0;
 310 }
 311
 312 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
 313 {
 314         unsigned char msb, lsb;
 315
 316         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 317
 318         /*
 319          * Convert celsius to fahrenheit, since this was
 320          * the decided 'standard' for this return value.
 321          */
 322         *temperature = (lsb * 9 / 5) + 32;
 323
 324         return 0;
 325 }
 326
 327 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left)
 328 {
 329         unsigned char msb, lsb;
 330
 331         /* Read the time that's left before rebooting */
 332         /* Note: if the board is not yet armed then we will read 0xFFFF */
 333         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 334
 335         *time_left = (msb << 8) + lsb;
 336
 337         return 0;
 338 }
 339
 340 /*
 341  *      /dev/watchdog handling
 342  */
 343
 344 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 345                               size_t len, loff_t *ppos)
 346 {
 347         /* See if we got the magic character 'V' and reload the timer */
 348         if (len) {
 349                 if (!nowayout) {
 350                         size_t i;
 351
 352                         /* note: just in case someone wrote the magic character
 353                          * five months ago... */
 354                         expect_release = 0;
 355
 356                         /* scan to see whether or not we got the magic character */
 357                         for (i = 0; i != len; i++) {
 358                                 char c;
 359                                 if(get_user(c, data+i))
 360                                         return -EFAULT;
 361                                 if (c == 'V')
 362                                         expect_release = 42;
 363                         }
 364                 }
 365
 366                 /* someone wrote to us, we should reload the timer */
 367                 usb_pcwd_keepalive(usb_pcwd_device);
 368         }
 369         return len;
 370 }
 371
 372 static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
 373                           unsigned int cmd, unsigned long arg)
 374 {
 375         void __user *argp = (void __user *)arg;
 376         int __user *p = argp;
 377         static struct watchdog_info ident = {
 378                 .options =              WDIOF_KEEPALIVEPING |
 379                                         WDIOF_SETTIMEOUT |
 380                                         WDIOF_MAGICCLOSE,
 381                 .firmware_version =     1,
 382                 .identity =             DRIVER_NAME,
 383         };
 384
 385         switch (cmd) {
 386                 case WDIOC_GETSUPPORT:
 387                         return copy_to_user(argp, &ident,
 388                                 sizeof (ident)) ? -EFAULT : 0;
 389
 390                 case WDIOC_GETSTATUS:
 391                 case WDIOC_GETBOOTSTATUS:
 392                         return put_user(0, p);
 393
 394                 case WDIOC_GETTEMP:
 395                 {
 396                         int temperature;
 397
 398                         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 399                                 return -EFAULT;
 400
 401                         return put_user(temperature, p);
 402                 }
 403
 404                 case WDIOC_KEEPALIVE:
 405                         usb_pcwd_keepalive(usb_pcwd_device);
 406                         return 0;
 407
 408                 case WDIOC_SETOPTIONS:
 409                 {
 410                         int new_options, retval = -EINVAL;
 411
 412                         if (get_user (new_options, p))
 413                                 return -EFAULT;
 414
 415                         if (new_options & WDIOS_DISABLECARD) {
 416                                 usb_pcwd_stop(usb_pcwd_device);
 417                                 retval = 0;
 418                         }
 419
 420                         if (new_options & WDIOS_ENABLECARD) {
 421                                 usb_pcwd_start(usb_pcwd_device);
 422                                 retval = 0;
 423                         }
 424
 425                         return retval;
 426                 }
 427
 428                 case WDIOC_SETTIMEOUT:
 429                 {
 430                         int new_heartbeat;
 431
 432                         if (get_user(new_heartbeat, p))
 433                                 return -EFAULT;
 434
 435                         if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 436                             return -EINVAL;
 437
 438                         usb_pcwd_keepalive(usb_pcwd_device);
 439                         /* Fall */
 440                 }
 441
 442                 case WDIOC_GETTIMEOUT:
 443                         return put_user(heartbeat, p);
 444
 445                 case WDIOC_GETTIMELEFT:
 446                 {
 447                         int time_left;
 448
 449                         if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 450                                 return -EFAULT;
 451
 452                         return put_user(time_left, p);
 453                 }
 454
 455                 default:
 456                         return -ENOTTY;
 457         }
 458 }
 459
 460 static int usb_pcwd_open(struct inode *inode, struct file *file)
 461 {
 462         /* /dev/watchdog can only be opened once */
 463         if (test_and_set_bit(0, &is_active))
 464                 return -EBUSY;
 465
 466         /* Activate */
 467         usb_pcwd_start(usb_pcwd_device);
 468         usb_pcwd_keepalive(usb_pcwd_device);
 469         return nonseekable_open(inode, file);
 470 }
 471
 472 static int usb_pcwd_release(struct inode *inode, struct file *file)
 473 {
 474         /*
 475          *      Shut off the timer.
 476          */
 477         if (expect_release == 42) {
 478                 usb_pcwd_stop(usb_pcwd_device);
 479         } else {
 480                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 481                 usb_pcwd_keepalive(usb_pcwd_device);
 482         }
 483         expect_release = 0;
 484         clear_bit(0, &is_active);
 485         return 0;
 486 }
 487
 488 /*
 489  *      /dev/temperature handling
 490  */
 491
 492 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 493                                 size_t len, loff_t *ppos)
 494 {
 495         int temperature;
 496
 497         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 498                 return -EFAULT;
 499
 500         if (copy_to_user(data, &temperature, 1))
 501                 return -EFAULT;
 502
 503         return 1;
 504 }
 505
 506 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 507 {
 508         return nonseekable_open(inode, file);
 509 }
 510
 511 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 512 {
 513         return 0;
 514 }
 515
 516 /*
 517  *      Notify system
 518  */
 519
 520 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 521 {
 522         if (code==SYS_DOWN || code==SYS_HALT) {
 523                 /* Turn the WDT off */
 524                 usb_pcwd_stop(usb_pcwd_device);
 525         }
 526
 527         return NOTIFY_DONE;
 528 }
 529
 530 /*
 531  *      Kernel Interfaces
 532  */
 533
 534 static const struct file_operations usb_pcwd_fops = {
 535         .owner =        THIS_MODULE,
 536         .llseek =       no_llseek,
 537         .write =        usb_pcwd_write,
 538         .ioctl =        usb_pcwd_ioctl,
 539         .open =         usb_pcwd_open,
 540         .release =      usb_pcwd_release,
 541 };
 542
 543 static struct miscdevice usb_pcwd_miscdev = {
 544         .minor =        WATCHDOG_MINOR,
 545         .name =         "watchdog",
 546         .fops =         &usb_pcwd_fops,
 547 };
 548
 549 static const struct file_operations usb_pcwd_temperature_fops = {
 550         .owner =        THIS_MODULE,
 551         .llseek =       no_llseek,
 552         .read =         usb_pcwd_temperature_read,
 553         .open =         usb_pcwd_temperature_open,
 554         .release =      usb_pcwd_temperature_release,
 555 };
 556
 557 static struct miscdevice usb_pcwd_temperature_miscdev = {
 558         .minor =        TEMP_MINOR,
 559         .name =         "temperature",
 560         .fops =         &usb_pcwd_temperature_fops,
 561 };
 562
 563 static struct notifier_block usb_pcwd_notifier = {
 564         .notifier_call =        usb_pcwd_notify_sys,
 565 };
 566
 567 /**
 568  *      usb_pcwd_delete
 569  */
 570 static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
 571 {
 572         usb_free_urb(usb_pcwd->intr_urb);
 573         if (usb_pcwd->intr_buffer != NULL)
 574                 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
 575                                 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 576         kfree (usb_pcwd);
 577 }
 578
 579 /**
 580  *      usb_pcwd_probe
 581  *
 582  *      Called by the usb core when a new device is connected that it thinks
 583  *      this driver might be interested in.
 584  */
 585 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
 586 {
 587         struct usb_device *udev = interface_to_usbdev(interface);
 588         struct usb_host_interface *iface_desc;
 589         struct usb_endpoint_descriptor *endpoint;
 590         struct usb_pcwd_private *usb_pcwd = NULL;
 591         int pipe, maxp;
 592         int retval = -ENOMEM;
 593         int got_fw_rev;
 594         unsigned char fw_rev_major, fw_rev_minor;
 595         char fw_ver_str[20];
 596         unsigned char option_switches, dummy;
 597
 598         cards_found++;
 599         if (cards_found > 1) {
 600                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 601                 return -ENODEV;
 602         }
 603
 604         /* get the active interface descriptor */
 605         iface_desc = interface->cur_altsetting;
 606
 607         /* check out that we have a HID device */
 608         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 609                 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
 610                 return -ENODEV;
 611         }
 612
 613         /* check out the endpoint: it has to be Interrupt & IN */
 614         endpoint = &iface_desc->endpoint[0].desc;
 615
 616         if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
 617              ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 618                                 == USB_ENDPOINT_XFER_INT))) {
 619                 /* we didn't find a Interrupt endpoint with direction IN */
 620                 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 621                 return -ENODEV;
 622         }
 623
 624         /* get a handle to the interrupt data pipe */
 625         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 626         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 627
 628         /* allocate memory for our device and initialize it */
 629         usb_pcwd = kzalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
 630         if (usb_pcwd == NULL) {
 631                 printk(KERN_ERR PFX "Out of memory\n");
 632                 goto error;
 633         }
 634
 635         usb_pcwd_device = usb_pcwd;
 636
 637         mutex_init(&usb_pcwd->mtx);
 638         usb_pcwd->udev = udev;
 639         usb_pcwd->interface = interface;
 640         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 641         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 642
 643         /* set up the memory buffer's */
 644         if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma))) {
 645                 printk(KERN_ERR PFX "Out of memory\n");
 646                 goto error;
 647         }
 648
 649         /* allocate the urb's */
 650         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 651         if (!usb_pcwd->intr_urb) {
 652                 printk(KERN_ERR PFX "Out of memory\n");
 653                 goto error;
 654         }
 655
 656         /* initialise the intr urb's */
 657         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 658                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 659                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 660         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 661         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 662
 663         /* register our interrupt URB with the USB system */
 664         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 665                 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 666                 retval = -EIO; /* failure */
 667                 goto error;
 668         }
 669
 670         /* The device exists and can be communicated with */
 671         usb_pcwd->exists = 1;
 672
 673         /* disable card */
 674         usb_pcwd_stop(usb_pcwd);
 675
 676         /* Get the Firmware Version */
 677         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
 678         if (got_fw_rev) {
 679                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 680         } else {
 681                 sprintf(fw_ver_str, "<card no answer>");
 682         }
 683
 684         printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 685                 fw_ver_str);
 686
 687         /* Get switch settings */
 688         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
 689
 690         printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 691                 option_switches,
 692                 ((option_switches & 0x10) ? "ON" : "OFF"),
 693                 ((option_switches & 0x08) ? "ON" : "OFF"));
 694
 695         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 696         if (heartbeat == 0)
 697                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 698
 699         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 700         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 701                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 702                 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
 703                         WATCHDOG_HEARTBEAT);
 704         }
 705
 706         retval = register_reboot_notifier(&usb_pcwd_notifier);
 707         if (retval != 0) {
 708                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 709                         retval);
 710                 goto error;
 711         }
 712
 713         retval = misc_register(&usb_pcwd_temperature_miscdev);
 714         if (retval != 0) {
 715                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 716                         TEMP_MINOR, retval);
 717                 goto err_out_unregister_reboot;
 718         }
 719
 720         retval = misc_register(&usb_pcwd_miscdev);
 721         if (retval != 0) {
 722                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 723                         WATCHDOG_MINOR, retval);
 724                 goto err_out_misc_deregister;
 725         }
 726
 727         /* we can register the device now, as it is ready */
 728         usb_set_intfdata (interface, usb_pcwd);
 729
 730         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 731                 heartbeat, nowayout);
 732
 733         return 0;
 734
 735 err_out_misc_deregister:
 736         misc_deregister(&usb_pcwd_temperature_miscdev);
 737 err_out_unregister_reboot:
 738         unregister_reboot_notifier(&usb_pcwd_notifier);
 739 error:
 740         if (usb_pcwd)
 741                 usb_pcwd_delete(usb_pcwd);
 742         usb_pcwd_device = NULL;
 743         return retval;
 744 }
 745
 746
 747 /**
 748  *      usb_pcwd_disconnect
 749  *
 750  *      Called by the usb core when the device is removed from the system.
 751  *
 752  *      This routine guarantees that the driver will not submit any more urbs
 753  *      by clearing dev->udev.
 754  */
 755 static void usb_pcwd_disconnect(struct usb_interface *interface)
 756 {
 757         struct usb_pcwd_private *usb_pcwd;
 758
 759         /* prevent races with open() */
 760         mutex_lock(&disconnect_mutex);
 761
 762         usb_pcwd = usb_get_intfdata (interface);
 763         usb_set_intfdata (interface, NULL);
 764
 765         mutex_lock(&usb_pcwd->mtx);
 766
 767         /* Stop the timer before we leave */
 768         if (!nowayout)
 769                 usb_pcwd_stop(usb_pcwd);
 770
 771         /* We should now stop communicating with the USB PCWD device */
 772         usb_pcwd->exists = 0;
 773
 774         /* Deregister */
 775         misc_deregister(&usb_pcwd_miscdev);
 776         misc_deregister(&usb_pcwd_temperature_miscdev);
 777         unregister_reboot_notifier(&usb_pcwd_notifier);
 778
 779         mutex_unlock(&usb_pcwd->mtx);
 780
 781         /* Delete the USB PCWD device */
 782         usb_pcwd_delete(usb_pcwd);
 783
 784         cards_found--;
 785
 786         mutex_unlock(&disconnect_mutex);
 787
 788         printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 789 }
 790
 791
 792
 793 /**
 794  *      usb_pcwd_init
 795  */
 796 static int __init usb_pcwd_init(void)
 797 {
 798         int result;
 799
 800         /* register this driver with the USB subsystem */
 801         result = usb_register(&usb_pcwd_driver);
 802         if (result) {
 803                 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
 804                     result);
 805                 return result;
 806         }
 807
 808         printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
 809         return 0;
 810 }
 811
 812
 813 /**
 814  *      usb_pcwd_exit
 815  */
 816 static void __exit usb_pcwd_exit(void)
 817 {
 818         /* deregister this driver with the USB subsystem */
 819         usb_deregister(&usb_pcwd_driver);
 820 }
 821
 822
 823 module_init (usb_pcwd_init);
 824 module_exit (usb_pcwd_exit);