drivers/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      Based on source code of the following authors:
   7  *        Ken Hollis <kenji@bitgate.com>,
   8  *        Alan Cox <alan@lxorguk.ukuu.org.uk>,
   9  *        Matt Domsch <Matt_Domsch@dell.com>,
  10  *        Rob Radez <rob@osinvestor.com>,
  11  *        Greg Kroah-Hartman <greg@kroah.com>
  12  *
  13  *      This program is free software; you can redistribute it and/or
  14  *      modify it under the terms of the GNU General Public License
  15  *      as published by the Free Software Foundation; either version
  16  *      2 of the License, or (at your option) any later version.
  17  *
  18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  19  *      provide warranty for any of this software. This material is
  20  *      provided "AS-IS" and at no charge.
  21  *
  22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  23  *      providing the test hardware. More info is available at
  24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  25  */
  26
  27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  28
  29 #include <linux/module.h>       /* For module specific items */
  30 #include <linux/moduleparam.h>  /* For new moduleparam's */
  31 #include <linux/types.h>        /* For standard types (like size_t) */
  32 #include <linux/errno.h>        /* For the -ENODEV/... values */
  33 #include <linux/kernel.h>       /* For printk/panic/... */
  34 #include <linux/delay.h>        /* For mdelay function */
  35 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  36 #include <linux/watchdog.h>     /* For the watchdog specific items */
  37 #include <linux/notifier.h>     /* For notifier support */
  38 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  39 #include <linux/init.h>         /* For __init/__exit/... */
  40 #include <linux/fs.h>           /* For file operations */
  41 #include <linux/usb.h>          /* For USB functions */
  42 #include <linux/slab.h>         /* For kmalloc, ... */
  43 #include <linux/mutex.h>        /* For mutex locking */
  44 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  45 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  46
  47 #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
  55 #undef dbg
  56 #ifndef DEBUG
  57 #define DEBUG
  58 #endif
  59 #define dbg(format, ...)                                \
  60 do {                                                    \
  61         if (debug)                                      \
  62                 pr_debug(format "\n", ##__VA_ARGS__);   \
  63 } while (0)
  64
  65 /* Module and Version Information */
  66 #define DRIVER_VERSION "1.02"
  67 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  68 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  69 #define DRIVER_LICENSE "GPL"
  70 #define DRIVER_NAME "pcwd_usb"
  71
  72 MODULE_AUTHOR(DRIVER_AUTHOR);
  73 MODULE_DESCRIPTION(DRIVER_DESC);
  74 MODULE_LICENSE(DRIVER_LICENSE);
  75 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
  76 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
  77
  78 /* Module Parameters */
  79 module_param(debug, int, 0);
  80 MODULE_PARM_DESC(debug, "Debug enabled or not");
  81
  82 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
  83                                                 delay-time from dip-switches */
  84 static int heartbeat = WATCHDOG_HEARTBEAT;
  85 module_param(heartbeat, int, 0);
  86 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
  87         "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
  88                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  89
  90 static bool nowayout = WATCHDOG_NOWAYOUT;
  91 module_param(nowayout, bool, 0);
  92 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  93                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  94
  95 /* The vendor and product id's for the USB-PC Watchdog card */
  96 #define USB_PCWD_VENDOR_ID      0x0c98
  97 #define USB_PCWD_PRODUCT_ID     0x1140
  98
  99 /* table of devices that work with this driver */
 100 static struct usb_device_id usb_pcwd_table[] = {
 101         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
 102         { }                                     /* Terminating entry */
 103 };
 104 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
 105
 106 /* according to documentation max. time to process a command for the USB
 107  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
 108 #define USB_COMMAND_TIMEOUT     250
 109
 110 /* Watchdog's internal commands */
 111 #define CMD_READ_TEMP                   0x02    /* Read Temperature;
 112                                                         Re-trigger Watchdog */
 113 #define CMD_TRIGGER                     CMD_READ_TEMP
 114 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 115 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 116 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 117 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 118 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
 119 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 120 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 121
 122 /* Watchdog's Dip Switch heartbeat values */
 123 static const int heartbeat_tbl[] = {
 124         5,      /* OFF-OFF-OFF  =  5 Sec  */
 125         10,     /* OFF-OFF-ON   = 10 Sec  */
 126         30,     /* OFF-ON-OFF   = 30 Sec  */
 127         60,     /* OFF-ON-ON    =  1 Min  */
 128         300,    /* ON-OFF-OFF   =  5 Min  */
 129         600,    /* ON-OFF-ON    = 10 Min  */
 130         1800,   /* ON-ON-OFF    = 30 Min  */
 131         3600,   /* ON-ON-ON     =  1 hour */
 132 };
 133
 134 /* We can only use 1 card due to the /dev/watchdog restriction */
 135 static int cards_found;
 136
 137 /* some internal variables */
 138 static unsigned long is_active;
 139 static char expect_release;
 140
 141 /* Structure to hold all of our device specific stuff */
 142 struct usb_pcwd_private {
 143         /* save off the usb device pointer */
 144         struct usb_device       *udev;
 145         /* the interface for this device */
 146         struct usb_interface    *interface;
 147
 148         /* the interface number used for cmd's */
 149         unsigned int            interface_number;
 150
 151         /* the buffer to intr data */
 152         unsigned char           *intr_buffer;
 153         /* the dma address for the intr buffer */
 154         dma_addr_t              intr_dma;
 155         /* the size of the intr buffer */
 156         size_t                  intr_size;
 157         /* the urb used for the intr pipe */
 158         struct urb              *intr_urb;
 159
 160         /* The command that is reported back */
 161         unsigned char           cmd_command;
 162         /* The data MSB that is reported back */
 163         unsigned char           cmd_data_msb;
 164         /* The data LSB that is reported back */
 165         unsigned char           cmd_data_lsb;
 166         /* true if we received a report after a command */
 167         atomic_t                cmd_received;
 168
 169         /* Wether or not the device exists */
 170         int                     exists;
 171         /* locks this structure */
 172         struct mutex            mtx;
 173 };
 174 static struct usb_pcwd_private *usb_pcwd_device;
 175
 176 /* prevent races between open() and disconnect() */
 177 static DEFINE_MUTEX(disconnect_mutex);
 178
 179 /* local function prototypes */
 180 static int usb_pcwd_probe(struct usb_interface *interface,
 181                                                 const struct usb_device_id *id);
 182 static void usb_pcwd_disconnect(struct usb_interface *interface);
 183
 184 /* usb specific object needed to register this driver with the usb subsystem */
 185 static struct usb_driver usb_pcwd_driver = {
 186         .name =         DRIVER_NAME,
 187         .probe =        usb_pcwd_probe,
 188         .disconnect =   usb_pcwd_disconnect,
 189         .id_table =     usb_pcwd_table,
 190 };
 191
 192
 193 static void usb_pcwd_intr_done(struct urb *urb)
 194 {
 195         struct usb_pcwd_private *usb_pcwd =
 196                                 (struct usb_pcwd_private *)urb->context;
 197         unsigned char *data = usb_pcwd->intr_buffer;
 198         int retval;
 199
 200         switch (urb->status) {
 201         case 0:                 /* success */
 202                 break;
 203         case -ECONNRESET:       /* unlink */
 204         case -ENOENT:
 205         case -ESHUTDOWN:
 206                 /* this urb is terminated, clean up */
 207                 dbg("%s - urb shutting down with status: %d", __func__,
 208                                                                 urb->status);
 209                 return;
 210         /* -EPIPE:  should clear the halt */
 211         default:                /* error */
 212                 dbg("%s - nonzero urb status received: %d", __func__,
 213                                                                 urb->status);
 214                 goto resubmit;
 215         }
 216
 217         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 218                 data[0], data[1], data[2]);
 219
 220         usb_pcwd->cmd_command  = data[0];
 221         usb_pcwd->cmd_data_msb = data[1];
 222         usb_pcwd->cmd_data_lsb = data[2];
 223
 224         /* notify anyone waiting that the cmd has finished */
 225         atomic_set(&usb_pcwd->cmd_received, 1);
 226
 227 resubmit:
 228         retval = usb_submit_urb(urb, GFP_ATOMIC);
 229         if (retval)
 230                 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
 231                        retval);
 232 }
 233
 234 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 235                 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 236 {
 237         int got_response, count;
 238         unsigned char buf[6];
 239
 240         /* We will not send any commands if the USB PCWD device does
 241          * not exist */
 242         if ((!usb_pcwd) || (!usb_pcwd->exists))
 243                 return -1;
 244
 245         /* The USB PC Watchdog uses a 6 byte report format.
 246          * The board currently uses only 3 of the six bytes of the report. */
 247         buf[0] = cmd;                   /* Byte 0 = CMD */
 248         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 249         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 250         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 251
 252         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 253                 buf[0], buf[1], buf[2]);
 254
 255         atomic_set(&usb_pcwd->cmd_received, 0);
 256
 257         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 258                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 259                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 260                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 261                 dbg("usb_pcwd_send_command: error in usb_control_msg for "
 262                                 "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 263         }
 264         /* wait till the usb card processed the command,
 265          * with a max. timeout of USB_COMMAND_TIMEOUT */
 266         got_response = 0;
 267         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
 268                                                                 count++) {
 269                 mdelay(1);
 270                 if (atomic_read(&usb_pcwd->cmd_received))
 271                         got_response = 1;
 272         }
 273
 274         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 275                 /* read back response */
 276                 *msb = usb_pcwd->cmd_data_msb;
 277                 *lsb = usb_pcwd->cmd_data_lsb;
 278         }
 279
 280         return got_response;
 281 }
 282
 283 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 284 {
 285         unsigned char msb = 0x00;
 286         unsigned char lsb = 0x00;
 287         int retval;
 288
 289         /* Enable Watchdog */
 290         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 291                                                                 &msb, &lsb);
 292
 293         if ((retval == 0) || (lsb == 0)) {
 294                 pr_err("Card did not acknowledge enable attempt\n");
 295                 return -1;
 296         }
 297
 298         return 0;
 299 }
 300
 301 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 302 {
 303         unsigned char msb = 0xA5;
 304         unsigned char lsb = 0xC3;
 305         int retval;
 306
 307         /* Disable Watchdog */
 308         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 309                                                                 &msb, &lsb);
 310
 311         if ((retval == 0) || (lsb != 0)) {
 312                 pr_err("Card did not acknowledge disable attempt\n");
 313                 return -1;
 314         }
 315
 316         return 0;
 317 }
 318
 319 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 320 {
 321         unsigned char dummy;
 322
 323         /* Re-trigger Watchdog */
 324         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 325
 326         return 0;
 327 }
 328
 329 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 330 {
 331         unsigned char msb = t / 256;
 332         unsigned char lsb = t % 256;
 333
 334         if ((t < 0x0001) || (t > 0xFFFF))
 335                 return -EINVAL;
 336
 337         /* Write new heartbeat to watchdog */
 338         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 339
 340         heartbeat = t;
 341         return 0;
 342 }
 343
 344 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 345                                                         int *temperature)
 346 {
 347         unsigned char msb, lsb;
 348
 349         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 350
 351         /*
 352          * Convert celsius to fahrenheit, since this was
 353          * the decided 'standard' for this return value.
 354          */
 355         *temperature = (lsb * 9 / 5) + 32;
 356
 357         return 0;
 358 }
 359
 360 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 361                                                                 int *time_left)
 362 {
 363         unsigned char msb, lsb;
 364
 365         /* Read the time that's left before rebooting */
 366         /* Note: if the board is not yet armed then we will read 0xFFFF */
 367         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 368
 369         *time_left = (msb << 8) + lsb;
 370
 371         return 0;
 372 }
 373
 374 /*
 375  *      /dev/watchdog handling
 376  */
 377
 378 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 379                                                 size_t len, loff_t *ppos)
 380 {
 381         /* See if we got the magic character 'V' and reload the timer */
 382         if (len) {
 383                 if (!nowayout) {
 384                         size_t i;
 385
 386                         /* note: just in case someone wrote the magic character
 387                          * five months ago... */
 388                         expect_release = 0;
 389
 390                         /* scan to see whether or not we got the
 391                          * magic character */
 392                         for (i = 0; i != len; i++) {
 393                                 char c;
 394                                 if (get_user(c, data + i))
 395                                         return -EFAULT;
 396                                 if (c == 'V')
 397                                         expect_release = 42;
 398                         }
 399                 }
 400
 401                 /* someone wrote to us, we should reload the timer */
 402                 usb_pcwd_keepalive(usb_pcwd_device);
 403         }
 404         return len;
 405 }
 406
 407 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 408                                                 unsigned long arg)
 409 {
 410         void __user *argp = (void __user *)arg;
 411         int __user *p = argp;
 412         static const struct watchdog_info ident = {
 413                 .options =              WDIOF_KEEPALIVEPING |
 414                                         WDIOF_SETTIMEOUT |
 415                                         WDIOF_MAGICCLOSE,
 416                 .firmware_version =     1,
 417                 .identity =             DRIVER_NAME,
 418         };
 419
 420         switch (cmd) {
 421         case WDIOC_GETSUPPORT:
 422                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 423
 424         case WDIOC_GETSTATUS:
 425         case WDIOC_GETBOOTSTATUS:
 426                 return put_user(0, p);
 427
 428         case WDIOC_GETTEMP:
 429         {
 430                 int temperature;
 431
 432                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 433                         return -EFAULT;
 434
 435                 return put_user(temperature, p);
 436         }
 437
 438         case WDIOC_SETOPTIONS:
 439         {
 440                 int new_options, retval = -EINVAL;
 441
 442                 if (get_user(new_options, p))
 443                         return -EFAULT;
 444
 445                 if (new_options & WDIOS_DISABLECARD) {
 446                         usb_pcwd_stop(usb_pcwd_device);
 447                         retval = 0;
 448                 }
 449
 450                 if (new_options & WDIOS_ENABLECARD) {
 451                         usb_pcwd_start(usb_pcwd_device);
 452                         retval = 0;
 453                 }
 454
 455                 return retval;
 456         }
 457
 458         case WDIOC_KEEPALIVE:
 459                 usb_pcwd_keepalive(usb_pcwd_device);
 460                 return 0;
 461
 462         case WDIOC_SETTIMEOUT:
 463         {
 464                 int new_heartbeat;
 465
 466                 if (get_user(new_heartbeat, p))
 467                         return -EFAULT;
 468
 469                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 470                         return -EINVAL;
 471
 472                 usb_pcwd_keepalive(usb_pcwd_device);
 473                 /* Fall */
 474         }
 475
 476         case WDIOC_GETTIMEOUT:
 477                 return put_user(heartbeat, p);
 478
 479         case WDIOC_GETTIMELEFT:
 480         {
 481                 int time_left;
 482
 483                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 484                         return -EFAULT;
 485
 486                 return put_user(time_left, p);
 487         }
 488
 489         default:
 490                 return -ENOTTY;
 491         }
 492 }
 493
 494 static int usb_pcwd_open(struct inode *inode, struct file *file)
 495 {
 496         /* /dev/watchdog can only be opened once */
 497         if (test_and_set_bit(0, &is_active))
 498                 return -EBUSY;
 499
 500         /* Activate */
 501         usb_pcwd_start(usb_pcwd_device);
 502         usb_pcwd_keepalive(usb_pcwd_device);
 503         return nonseekable_open(inode, file);
 504 }
 505
 506 static int usb_pcwd_release(struct inode *inode, struct file *file)
 507 {
 508         /*
 509          *      Shut off the timer.
 510          */
 511         if (expect_release == 42) {
 512                 usb_pcwd_stop(usb_pcwd_device);
 513         } else {
 514                 pr_crit("Unexpected close, not stopping watchdog!\n");
 515                 usb_pcwd_keepalive(usb_pcwd_device);
 516         }
 517         expect_release = 0;
 518         clear_bit(0, &is_active);
 519         return 0;
 520 }
 521
 522 /*
 523  *      /dev/temperature handling
 524  */
 525
 526 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 527                                 size_t len, loff_t *ppos)
 528 {
 529         int temperature;
 530
 531         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 532                 return -EFAULT;
 533
 534         if (copy_to_user(data, &temperature, 1))
 535                 return -EFAULT;
 536
 537         return 1;
 538 }
 539
 540 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 541 {
 542         return nonseekable_open(inode, file);
 543 }
 544
 545 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 546 {
 547         return 0;
 548 }
 549
 550 /*
 551  *      Notify system
 552  */
 553
 554 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 555                                                                 void *unused)
 556 {
 557         if (code == SYS_DOWN || code == SYS_HALT)
 558                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 559
 560         return NOTIFY_DONE;
 561 }
 562
 563 /*
 564  *      Kernel Interfaces
 565  */
 566
 567 static const struct file_operations usb_pcwd_fops = {
 568         .owner =        THIS_MODULE,
 569         .llseek =       no_llseek,
 570         .write =        usb_pcwd_write,
 571         .unlocked_ioctl = usb_pcwd_ioctl,
 572         .open =         usb_pcwd_open,
 573         .release =      usb_pcwd_release,
 574 };
 575
 576 static struct miscdevice usb_pcwd_miscdev = {
 577         .minor =        WATCHDOG_MINOR,
 578         .name =         "watchdog",
 579         .fops =         &usb_pcwd_fops,
 580 };
 581
 582 static const struct file_operations usb_pcwd_temperature_fops = {
 583         .owner =        THIS_MODULE,
 584         .llseek =       no_llseek,
 585         .read =         usb_pcwd_temperature_read,
 586         .open =         usb_pcwd_temperature_open,
 587         .release =      usb_pcwd_temperature_release,
 588 };
 589
 590 static struct miscdevice usb_pcwd_temperature_miscdev = {
 591         .minor =        TEMP_MINOR,
 592         .name =         "temperature",
 593         .fops =         &usb_pcwd_temperature_fops,
 594 };
 595
 596 static struct notifier_block usb_pcwd_notifier = {
 597         .notifier_call =        usb_pcwd_notify_sys,
 598 };
 599
 600 /**
 601  *      usb_pcwd_delete
 602  */
 603 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 604 {
 605         usb_free_urb(usb_pcwd->intr_urb);
 606         if (usb_pcwd->intr_buffer != NULL)
 607                 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 608                                   usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 609         kfree(usb_pcwd);
 610 }
 611
 612 /**
 613  *      usb_pcwd_probe
 614  *
 615  *      Called by the usb core when a new device is connected that it thinks
 616  *      this driver might be interested in.
 617  */
 618 static int usb_pcwd_probe(struct usb_interface *interface,
 619                                                 const struct usb_device_id *id)
 620 {
 621         struct usb_device *udev = interface_to_usbdev(interface);
 622         struct usb_host_interface *iface_desc;
 623         struct usb_endpoint_descriptor *endpoint;
 624         struct usb_pcwd_private *usb_pcwd = NULL;
 625         int pipe, maxp;
 626         int retval = -ENOMEM;
 627         int got_fw_rev;
 628         unsigned char fw_rev_major, fw_rev_minor;
 629         char fw_ver_str[20];
 630         unsigned char option_switches, dummy;
 631
 632         cards_found++;
 633         if (cards_found > 1) {
 634                 pr_err("This driver only supports 1 device\n");
 635                 return -ENODEV;
 636         }
 637
 638         /* get the active interface descriptor */
 639         iface_desc = interface->cur_altsetting;
 640
 641         /* check out that we have a HID device */
 642         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 643                 pr_err("The device isn't a Human Interface Device\n");
 644                 return -ENODEV;
 645         }
 646
 647         /* check out the endpoint: it has to be Interrupt & IN */
 648         endpoint = &iface_desc->endpoint[0].desc;
 649
 650         if (!usb_endpoint_is_int_in(endpoint)) {
 651                 /* we didn't find a Interrupt endpoint with direction IN */
 652                 pr_err("Couldn't find an INTR & IN endpoint\n");
 653                 return -ENODEV;
 654         }
 655
 656         /* get a handle to the interrupt data pipe */
 657         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 658         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 659
 660         /* allocate memory for our device and initialize it */
 661         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 662         if (usb_pcwd == NULL) {
 663                 pr_err("Out of memory\n");
 664                 goto error;
 665         }
 666
 667         usb_pcwd_device = usb_pcwd;
 668
 669         mutex_init(&usb_pcwd->mtx);
 670         usb_pcwd->udev = udev;
 671         usb_pcwd->interface = interface;
 672         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 673         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 674                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 675
 676         /* set up the memory buffer's */
 677         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 678                                         GFP_ATOMIC, &usb_pcwd->intr_dma);
 679         if (!usb_pcwd->intr_buffer) {
 680                 pr_err("Out of memory\n");
 681                 goto error;
 682         }
 683
 684         /* allocate the urb's */
 685         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 686         if (!usb_pcwd->intr_urb) {
 687                 pr_err("Out of memory\n");
 688                 goto error;
 689         }
 690
 691         /* initialise the intr urb's */
 692         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 693                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 694                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 695         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 696         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 697
 698         /* register our interrupt URB with the USB system */
 699         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 700                 pr_err("Problem registering interrupt URB\n");
 701                 retval = -EIO; /* failure */
 702                 goto error;
 703         }
 704
 705         /* The device exists and can be communicated with */
 706         usb_pcwd->exists = 1;
 707
 708         /* disable card */
 709         usb_pcwd_stop(usb_pcwd);
 710
 711         /* Get the Firmware Version */
 712         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 713                                                 &fw_rev_major, &fw_rev_minor);
 714         if (got_fw_rev)
 715                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 716         else
 717                 sprintf(fw_ver_str, "<card no answer>");
 718
 719         pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
 720
 721         /* Get switch settings */
 722         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 723                                                         &option_switches);
 724
 725         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 726                 option_switches,
 727                 ((option_switches & 0x10) ? "ON" : "OFF"),
 728                 ((option_switches & 0x08) ? "ON" : "OFF"));
 729
 730         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 731         if (heartbeat == 0)
 732                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 733
 734         /* Check that the heartbeat value is within it's range ;
 735          * if not reset to the default */
 736         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 737                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 738                 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
 739                         WATCHDOG_HEARTBEAT);
 740         }
 741
 742         retval = register_reboot_notifier(&usb_pcwd_notifier);
 743         if (retval != 0) {
 744                 pr_err("cannot register reboot notifier (err=%d)\n", retval);
 745                 goto error;
 746         }
 747
 748         retval = misc_register(&usb_pcwd_temperature_miscdev);
 749         if (retval != 0) {
 750                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 751                        TEMP_MINOR, retval);
 752                 goto err_out_unregister_reboot;
 753         }
 754
 755         retval = misc_register(&usb_pcwd_miscdev);
 756         if (retval != 0) {
 757                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 758                        WATCHDOG_MINOR, retval);
 759                 goto err_out_misc_deregister;
 760         }
 761
 762         /* we can register the device now, as it is ready */
 763         usb_set_intfdata(interface, usb_pcwd);
 764
 765         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 766                 heartbeat, nowayout);
 767
 768         return 0;
 769
 770 err_out_misc_deregister:
 771         misc_deregister(&usb_pcwd_temperature_miscdev);
 772 err_out_unregister_reboot:
 773         unregister_reboot_notifier(&usb_pcwd_notifier);
 774 error:
 775         if (usb_pcwd)
 776                 usb_pcwd_delete(usb_pcwd);
 777         usb_pcwd_device = NULL;
 778         return retval;
 779 }
 780
 781
 782 /**
 783  *      usb_pcwd_disconnect
 784  *
 785  *      Called by the usb core when the device is removed from the system.
 786  *
 787  *      This routine guarantees that the driver will not submit any more urbs
 788  *      by clearing dev->udev.
 789  */
 790 static void usb_pcwd_disconnect(struct usb_interface *interface)
 791 {
 792         struct usb_pcwd_private *usb_pcwd;
 793
 794         /* prevent races with open() */
 795         mutex_lock(&disconnect_mutex);
 796
 797         usb_pcwd = usb_get_intfdata(interface);
 798         usb_set_intfdata(interface, NULL);
 799
 800         mutex_lock(&usb_pcwd->mtx);
 801
 802         /* Stop the timer before we leave */
 803         if (!nowayout)
 804                 usb_pcwd_stop(usb_pcwd);
 805
 806         /* We should now stop communicating with the USB PCWD device */
 807         usb_pcwd->exists = 0;
 808
 809         /* Deregister */
 810         misc_deregister(&usb_pcwd_miscdev);
 811         misc_deregister(&usb_pcwd_temperature_miscdev);
 812         unregister_reboot_notifier(&usb_pcwd_notifier);
 813
 814         mutex_unlock(&usb_pcwd->mtx);
 815
 816         /* Delete the USB PCWD device */
 817         usb_pcwd_delete(usb_pcwd);
 818
 819         cards_found--;
 820
 821         mutex_unlock(&disconnect_mutex);
 822
 823         pr_info("USB PC Watchdog disconnected\n");
 824 }
 825
 826 module_usb_driver(usb_pcwd_driver);