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