drivers/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      Based on source code of the following authors:
   7  *        Ken Hollis <kenji@bitgate.com>,
   8  *        Alan Cox <alan@lxorguk.ukuu.org.uk>,
   9  *        Matt Domsch <Matt_Domsch@dell.com>,
  10  *        Rob Radez <rob@osinvestor.com>,
  11  *        Greg Kroah-Hartman <greg@kroah.com>
  12  *
  13  *      This program is free software; you can redistribute it and/or
  14  *      modify it under the terms of the GNU General Public License
  15  *      as published by the Free Software Foundation; either version
  16  *      2 of the License, or (at your option) any later version.
  17  *
  18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  19  *      provide warranty for any of this software. This material is
  20  *      provided "AS-IS" and at no charge.
  21  *
  22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  23  *      providing the test hardware. More info is available at
  24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  25  */
  26
  27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  28
  29 #include <linux/module.h>       /* For module specific items */
  30 #include <linux/moduleparam.h>  /* For new moduleparam's */
  31 #include <linux/types.h>        /* For standard types (like size_t) */
  32 #include <linux/errno.h>        /* For the -ENODEV/... values */
  33 #include <linux/kernel.h>       /* For printk/panic/... */
  34 #include <linux/delay.h>        /* For mdelay function */
  35 #include <linux/miscdevice.h>   /* For struct miscdevice */
  36 #include <linux/watchdog.h>     /* For the watchdog specific items */
  37 #include <linux/notifier.h>     /* For notifier support */
  38 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  39 #include <linux/init.h>         /* For __init/__exit/... */
  40 #include <linux/fs.h>           /* For file operations */
  41 #include <linux/usb.h>          /* For USB functions */
  42 #include <linux/slab.h>         /* For kmalloc, ... */
  43 #include <linux/mutex.h>        /* For mutex locking */
  44 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  45 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  46
  47 #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
  76 /* Module Parameters */
  77 module_param(debug, int, 0);
  78 MODULE_PARM_DESC(debug, "Debug enabled or not");
  79
  80 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
  81                                                 delay-time from dip-switches */
  82 static int heartbeat = WATCHDOG_HEARTBEAT;
  83 module_param(heartbeat, int, 0);
  84 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
  85         "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
  86                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  87
  88 static bool nowayout = WATCHDOG_NOWAYOUT;
  89 module_param(nowayout, bool, 0);
  90 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  91                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  92
  93 /* The vendor and product id's for the USB-PC Watchdog card */
  94 #define USB_PCWD_VENDOR_ID      0x0c98
  95 #define USB_PCWD_PRODUCT_ID     0x1140
  96
  97 /* table of devices that work with this driver */
  98 static struct usb_device_id usb_pcwd_table[] = {
  99         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
 100         { }                                     /* Terminating entry */
 101 };
 102 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
 103
 104 /* according to documentation max. time to process a command for the USB
 105  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
 106 #define USB_COMMAND_TIMEOUT     250
 107
 108 /* Watchdog's internal commands */
 109 #define CMD_READ_TEMP                   0x02    /* Read Temperature;
 110                                                         Re-trigger Watchdog */
 111 #define CMD_TRIGGER                     CMD_READ_TEMP
 112 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 113 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 114 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 115 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 116 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
 117 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 118 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 119
 120 /* Watchdog's Dip Switch heartbeat values */
 121 static const int heartbeat_tbl[] = {
 122         5,      /* OFF-OFF-OFF  =  5 Sec  */
 123         10,     /* OFF-OFF-ON   = 10 Sec  */
 124         30,     /* OFF-ON-OFF   = 30 Sec  */
 125         60,     /* OFF-ON-ON    =  1 Min  */
 126         300,    /* ON-OFF-OFF   =  5 Min  */
 127         600,    /* ON-OFF-ON    = 10 Min  */
 128         1800,   /* ON-ON-OFF    = 30 Min  */
 129         3600,   /* ON-ON-ON     =  1 hour */
 130 };
 131
 132 /* We can only use 1 card due to the /dev/watchdog restriction */
 133 static int cards_found;
 134
 135 /* some internal variables */
 136 static unsigned long is_active;
 137 static char expect_release;
 138
 139 /* Structure to hold all of our device specific stuff */
 140 struct usb_pcwd_private {
 141         /* save off the usb device pointer */
 142         struct usb_device       *udev;
 143         /* the interface for this device */
 144         struct usb_interface    *interface;
 145
 146         /* the interface number used for cmd's */
 147         unsigned int            interface_number;
 148
 149         /* the buffer to intr data */
 150         unsigned char           *intr_buffer;
 151         /* the dma address for the intr buffer */
 152         dma_addr_t              intr_dma;
 153         /* the size of the intr buffer */
 154         size_t                  intr_size;
 155         /* the urb used for the intr pipe */
 156         struct urb              *intr_urb;
 157
 158         /* The command that is reported back */
 159         unsigned char           cmd_command;
 160         /* The data MSB that is reported back */
 161         unsigned char           cmd_data_msb;
 162         /* The data LSB that is reported back */
 163         unsigned char           cmd_data_lsb;
 164         /* true if we received a report after a command */
 165         atomic_t                cmd_received;
 166
 167         /* Wether or not the device exists */
 168         int                     exists;
 169         /* locks this structure */
 170         struct mutex            mtx;
 171 };
 172 static struct usb_pcwd_private *usb_pcwd_device;
 173
 174 /* prevent races between open() and disconnect() */
 175 static DEFINE_MUTEX(disconnect_mutex);
 176
 177 /* local function prototypes */
 178 static int usb_pcwd_probe(struct usb_interface *interface,
 179                                                 const struct usb_device_id *id);
 180 static void usb_pcwd_disconnect(struct usb_interface *interface);
 181
 182 /* usb specific object needed to register this driver with the usb subsystem */
 183 static struct usb_driver usb_pcwd_driver = {
 184         .name =         DRIVER_NAME,
 185         .probe =        usb_pcwd_probe,
 186         .disconnect =   usb_pcwd_disconnect,
 187         .id_table =     usb_pcwd_table,
 188 };
 189
 190
 191 static void usb_pcwd_intr_done(struct urb *urb)
 192 {
 193         struct usb_pcwd_private *usb_pcwd =
 194                                 (struct usb_pcwd_private *)urb->context;
 195         unsigned char *data = usb_pcwd->intr_buffer;
 196         int retval;
 197
 198         switch (urb->status) {
 199         case 0:                 /* success */
 200                 break;
 201         case -ECONNRESET:       /* unlink */
 202         case -ENOENT:
 203         case -ESHUTDOWN:
 204                 /* this urb is terminated, clean up */
 205                 dbg("%s - urb shutting down with status: %d", __func__,
 206                                                                 urb->status);
 207                 return;
 208         /* -EPIPE:  should clear the halt */
 209         default:                /* error */
 210                 dbg("%s - nonzero urb status received: %d", __func__,
 211                                                                 urb->status);
 212                 goto resubmit;
 213         }
 214
 215         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 216                 data[0], data[1], data[2]);
 217
 218         usb_pcwd->cmd_command  = data[0];
 219         usb_pcwd->cmd_data_msb = data[1];
 220         usb_pcwd->cmd_data_lsb = data[2];
 221
 222         /* notify anyone waiting that the cmd has finished */
 223         atomic_set(&usb_pcwd->cmd_received, 1);
 224
 225 resubmit:
 226         retval = usb_submit_urb(urb, GFP_ATOMIC);
 227         if (retval)
 228                 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
 229                        retval);
 230 }
 231
 232 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 233                 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 234 {
 235         int got_response, count;
 236         unsigned char *buf;
 237
 238         /* We will not send any commands if the USB PCWD device does
 239          * not exist */
 240         if ((!usb_pcwd) || (!usb_pcwd->exists))
 241                 return -1;
 242
 243         buf = kmalloc(6, GFP_KERNEL);
 244         if (buf == NULL)
 245                 return 0;
 246
 247         /* The USB PC Watchdog uses a 6 byte report format.
 248          * The board currently uses only 3 of the six bytes of the report. */
 249         buf[0] = cmd;                   /* Byte 0 = CMD */
 250         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 251         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 252         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 253
 254         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 255                 buf[0], buf[1], buf[2]);
 256
 257         atomic_set(&usb_pcwd->cmd_received, 0);
 258
 259         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 260                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 261                         0x0200, usb_pcwd->interface_number, buf, 6,
 262                         USB_COMMAND_TIMEOUT) != 6) {
 263                 dbg("usb_pcwd_send_command: error in usb_control_msg for "
 264                                 "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 265         }
 266         /* wait till the usb card processed the command,
 267          * with a max. timeout of USB_COMMAND_TIMEOUT */
 268         got_response = 0;
 269         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
 270                                                                 count++) {
 271                 mdelay(1);
 272                 if (atomic_read(&usb_pcwd->cmd_received))
 273                         got_response = 1;
 274         }
 275
 276         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 277                 /* read back response */
 278                 *msb = usb_pcwd->cmd_data_msb;
 279                 *lsb = usb_pcwd->cmd_data_lsb;
 280         }
 281
 282         kfree(buf);
 283
 284         return got_response;
 285 }
 286
 287 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 288 {
 289         unsigned char msb = 0x00;
 290         unsigned char lsb = 0x00;
 291         int retval;
 292
 293         /* Enable Watchdog */
 294         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 295                                                                 &msb, &lsb);
 296
 297         if ((retval == 0) || (lsb == 0)) {
 298                 pr_err("Card did not acknowledge enable attempt\n");
 299                 return -1;
 300         }
 301
 302         return 0;
 303 }
 304
 305 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 306 {
 307         unsigned char msb = 0xA5;
 308         unsigned char lsb = 0xC3;
 309         int retval;
 310
 311         /* Disable Watchdog */
 312         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 313                                                                 &msb, &lsb);
 314
 315         if ((retval == 0) || (lsb != 0)) {
 316                 pr_err("Card did not acknowledge disable attempt\n");
 317                 return -1;
 318         }
 319
 320         return 0;
 321 }
 322
 323 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 324 {
 325         unsigned char dummy;
 326
 327         /* Re-trigger Watchdog */
 328         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 329
 330         return 0;
 331 }
 332
 333 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 334 {
 335         unsigned char msb = t / 256;
 336         unsigned char lsb = t % 256;
 337
 338         if ((t < 0x0001) || (t > 0xFFFF))
 339                 return -EINVAL;
 340
 341         /* Write new heartbeat to watchdog */
 342         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 343
 344         heartbeat = t;
 345         return 0;
 346 }
 347
 348 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 349                                                         int *temperature)
 350 {
 351         unsigned char msb, lsb;
 352
 353         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 354
 355         /*
 356          * Convert celsius to fahrenheit, since this was
 357          * the decided 'standard' for this return value.
 358          */
 359         *temperature = (lsb * 9 / 5) + 32;
 360
 361         return 0;
 362 }
 363
 364 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 365                                                                 int *time_left)
 366 {
 367         unsigned char msb, lsb;
 368
 369         /* Read the time that's left before rebooting */
 370         /* Note: if the board is not yet armed then we will read 0xFFFF */
 371         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 372
 373         *time_left = (msb << 8) + lsb;
 374
 375         return 0;
 376 }
 377
 378 /*
 379  *      /dev/watchdog handling
 380  */
 381
 382 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 383                                                 size_t len, loff_t *ppos)
 384 {
 385         /* See if we got the magic character 'V' and reload the timer */
 386         if (len) {
 387                 if (!nowayout) {
 388                         size_t i;
 389
 390                         /* note: just in case someone wrote the magic character
 391                          * five months ago... */
 392                         expect_release = 0;
 393
 394                         /* scan to see whether or not we got the
 395                          * magic character */
 396                         for (i = 0; i != len; i++) {
 397                                 char c;
 398                                 if (get_user(c, data + i))
 399                                         return -EFAULT;
 400                                 if (c == 'V')
 401                                         expect_release = 42;
 402                         }
 403                 }
 404
 405                 /* someone wrote to us, we should reload the timer */
 406                 usb_pcwd_keepalive(usb_pcwd_device);
 407         }
 408         return len;
 409 }
 410
 411 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 412                                                 unsigned long arg)
 413 {
 414         void __user *argp = (void __user *)arg;
 415         int __user *p = argp;
 416         static const struct watchdog_info ident = {
 417                 .options =              WDIOF_KEEPALIVEPING |
 418                                         WDIOF_SETTIMEOUT |
 419                                         WDIOF_MAGICCLOSE,
 420                 .firmware_version =     1,
 421                 .identity =             DRIVER_NAME,
 422         };
 423
 424         switch (cmd) {
 425         case WDIOC_GETSUPPORT:
 426                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 427
 428         case WDIOC_GETSTATUS:
 429         case WDIOC_GETBOOTSTATUS:
 430                 return put_user(0, p);
 431
 432         case WDIOC_GETTEMP:
 433         {
 434                 int temperature;
 435
 436                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 437                         return -EFAULT;
 438
 439                 return put_user(temperature, p);
 440         }
 441
 442         case WDIOC_SETOPTIONS:
 443         {
 444                 int new_options, retval = -EINVAL;
 445
 446                 if (get_user(new_options, p))
 447                         return -EFAULT;
 448
 449                 if (new_options & WDIOS_DISABLECARD) {
 450                         usb_pcwd_stop(usb_pcwd_device);
 451                         retval = 0;
 452                 }
 453
 454                 if (new_options & WDIOS_ENABLECARD) {
 455                         usb_pcwd_start(usb_pcwd_device);
 456                         retval = 0;
 457                 }
 458
 459                 return retval;
 460         }
 461
 462         case WDIOC_KEEPALIVE:
 463                 usb_pcwd_keepalive(usb_pcwd_device);
 464                 return 0;
 465
 466         case WDIOC_SETTIMEOUT:
 467         {
 468                 int new_heartbeat;
 469
 470                 if (get_user(new_heartbeat, p))
 471                         return -EFAULT;
 472
 473                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 474                         return -EINVAL;
 475
 476                 usb_pcwd_keepalive(usb_pcwd_device);
 477                 /* Fall */
 478         }
 479
 480         case WDIOC_GETTIMEOUT:
 481                 return put_user(heartbeat, p);
 482
 483         case WDIOC_GETTIMELEFT:
 484         {
 485                 int time_left;
 486
 487                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 488                         return -EFAULT;
 489
 490                 return put_user(time_left, p);
 491         }
 492
 493         default:
 494                 return -ENOTTY;
 495         }
 496 }
 497
 498 static int usb_pcwd_open(struct inode *inode, struct file *file)
 499 {
 500         /* /dev/watchdog can only be opened once */
 501         if (test_and_set_bit(0, &is_active))
 502                 return -EBUSY;
 503
 504         /* Activate */
 505         usb_pcwd_start(usb_pcwd_device);
 506         usb_pcwd_keepalive(usb_pcwd_device);
 507         return nonseekable_open(inode, file);
 508 }
 509
 510 static int usb_pcwd_release(struct inode *inode, struct file *file)
 511 {
 512         /*
 513          *      Shut off the timer.
 514          */
 515         if (expect_release == 42) {
 516                 usb_pcwd_stop(usb_pcwd_device);
 517         } else {
 518                 pr_crit("Unexpected close, not stopping watchdog!\n");
 519                 usb_pcwd_keepalive(usb_pcwd_device);
 520         }
 521         expect_release = 0;
 522         clear_bit(0, &is_active);
 523         return 0;
 524 }
 525
 526 /*
 527  *      /dev/temperature handling
 528  */
 529
 530 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 531                                 size_t len, loff_t *ppos)
 532 {
 533         int temperature;
 534
 535         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 536                 return -EFAULT;
 537
 538         if (copy_to_user(data, &temperature, 1))
 539                 return -EFAULT;
 540
 541         return 1;
 542 }
 543
 544 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 545 {
 546         return nonseekable_open(inode, file);
 547 }
 548
 549 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 550 {
 551         return 0;
 552 }
 553
 554 /*
 555  *      Notify system
 556  */
 557
 558 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 559                                                                 void *unused)
 560 {
 561         if (code == SYS_DOWN || code == SYS_HALT)
 562                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 563
 564         return NOTIFY_DONE;
 565 }
 566
 567 /*
 568  *      Kernel Interfaces
 569  */
 570
 571 static const struct file_operations usb_pcwd_fops = {
 572         .owner =        THIS_MODULE,
 573         .llseek =       no_llseek,
 574         .write =        usb_pcwd_write,
 575         .unlocked_ioctl = usb_pcwd_ioctl,
 576         .open =         usb_pcwd_open,
 577         .release =      usb_pcwd_release,
 578 };
 579
 580 static struct miscdevice usb_pcwd_miscdev = {
 581         .minor =        WATCHDOG_MINOR,
 582         .name =         "watchdog",
 583         .fops =         &usb_pcwd_fops,
 584 };
 585
 586 static const struct file_operations usb_pcwd_temperature_fops = {
 587         .owner =        THIS_MODULE,
 588         .llseek =       no_llseek,
 589         .read =         usb_pcwd_temperature_read,
 590         .open =         usb_pcwd_temperature_open,
 591         .release =      usb_pcwd_temperature_release,
 592 };
 593
 594 static struct miscdevice usb_pcwd_temperature_miscdev = {
 595         .minor =        TEMP_MINOR,
 596         .name =         "temperature",
 597         .fops =         &usb_pcwd_temperature_fops,
 598 };
 599
 600 static struct notifier_block usb_pcwd_notifier = {
 601         .notifier_call =        usb_pcwd_notify_sys,
 602 };
 603
 604 /**
 605  *      usb_pcwd_delete
 606  */
 607 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 608 {
 609         usb_free_urb(usb_pcwd->intr_urb);
 610         if (usb_pcwd->intr_buffer != NULL)
 611                 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 612                                   usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 613         kfree(usb_pcwd);
 614 }
 615
 616 /**
 617  *      usb_pcwd_probe
 618  *
 619  *      Called by the usb core when a new device is connected that it thinks
 620  *      this driver might be interested in.
 621  */
 622 static int usb_pcwd_probe(struct usb_interface *interface,
 623                                                 const struct usb_device_id *id)
 624 {
 625         struct usb_device *udev = interface_to_usbdev(interface);
 626         struct usb_host_interface *iface_desc;
 627         struct usb_endpoint_descriptor *endpoint;
 628         struct usb_pcwd_private *usb_pcwd = NULL;
 629         int pipe, maxp;
 630         int retval = -ENOMEM;
 631         int got_fw_rev;
 632         unsigned char fw_rev_major, fw_rev_minor;
 633         char fw_ver_str[20];
 634         unsigned char option_switches, dummy;
 635
 636         cards_found++;
 637         if (cards_found > 1) {
 638                 pr_err("This driver only supports 1 device\n");
 639                 return -ENODEV;
 640         }
 641
 642         /* get the active interface descriptor */
 643         iface_desc = interface->cur_altsetting;
 644
 645         /* check out that we have a HID device */
 646         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 647                 pr_err("The device isn't a Human Interface Device\n");
 648                 return -ENODEV;
 649         }
 650
 651         /* check out the endpoint: it has to be Interrupt & IN */
 652         endpoint = &iface_desc->endpoint[0].desc;
 653
 654         if (!usb_endpoint_is_int_in(endpoint)) {
 655                 /* we didn't find a Interrupt endpoint with direction IN */
 656                 pr_err("Couldn't find an INTR & IN endpoint\n");
 657                 return -ENODEV;
 658         }
 659
 660         /* get a handle to the interrupt data pipe */
 661         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 662         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 663
 664         /* allocate memory for our device and initialize it */
 665         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 666         if (usb_pcwd == NULL) {
 667                 pr_err("Out of memory\n");
 668                 goto error;
 669         }
 670
 671         usb_pcwd_device = usb_pcwd;
 672
 673         mutex_init(&usb_pcwd->mtx);
 674         usb_pcwd->udev = udev;
 675         usb_pcwd->interface = interface;
 676         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 677         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 678                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 679
 680         /* set up the memory buffer's */
 681         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 682                                         GFP_ATOMIC, &usb_pcwd->intr_dma);
 683         if (!usb_pcwd->intr_buffer) {
 684                 pr_err("Out of memory\n");
 685                 goto error;
 686         }
 687
 688         /* allocate the urb's */
 689         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 690         if (!usb_pcwd->intr_urb) {
 691                 pr_err("Out of memory\n");
 692                 goto error;
 693         }
 694
 695         /* initialise the intr urb's */
 696         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 697                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 698                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 699         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 700         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 701
 702         /* register our interrupt URB with the USB system */
 703         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 704                 pr_err("Problem registering interrupt URB\n");
 705                 retval = -EIO; /* failure */
 706                 goto error;
 707         }
 708
 709         /* The device exists and can be communicated with */
 710         usb_pcwd->exists = 1;
 711
 712         /* disable card */
 713         usb_pcwd_stop(usb_pcwd);
 714
 715         /* Get the Firmware Version */
 716         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 717                                                 &fw_rev_major, &fw_rev_minor);
 718         if (got_fw_rev)
 719                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 720         else
 721                 sprintf(fw_ver_str, "<card no answer>");
 722
 723         pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
 724
 725         /* Get switch settings */
 726         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 727                                                         &option_switches);
 728
 729         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 730                 option_switches,
 731                 ((option_switches & 0x10) ? "ON" : "OFF"),
 732                 ((option_switches & 0x08) ? "ON" : "OFF"));
 733
 734         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 735         if (heartbeat == 0)
 736                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 737
 738         /* Check that the heartbeat value is within it's range ;
 739          * if not reset to the default */
 740         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 741                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 742                 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
 743                         WATCHDOG_HEARTBEAT);
 744         }
 745
 746         retval = register_reboot_notifier(&usb_pcwd_notifier);
 747         if (retval != 0) {
 748                 pr_err("cannot register reboot notifier (err=%d)\n", retval);
 749                 goto error;
 750         }
 751
 752         retval = misc_register(&usb_pcwd_temperature_miscdev);
 753         if (retval != 0) {
 754                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 755                        TEMP_MINOR, retval);
 756                 goto err_out_unregister_reboot;
 757         }
 758
 759         retval = misc_register(&usb_pcwd_miscdev);
 760         if (retval != 0) {
 761                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 762                        WATCHDOG_MINOR, retval);
 763                 goto err_out_misc_deregister;
 764         }
 765
 766         /* we can register the device now, as it is ready */
 767         usb_set_intfdata(interface, usb_pcwd);
 768
 769         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 770                 heartbeat, nowayout);
 771
 772         return 0;
 773
 774 err_out_misc_deregister:
 775         misc_deregister(&usb_pcwd_temperature_miscdev);
 776 err_out_unregister_reboot:
 777         unregister_reboot_notifier(&usb_pcwd_notifier);
 778 error:
 779         if (usb_pcwd)
 780                 usb_pcwd_delete(usb_pcwd);
 781         usb_pcwd_device = NULL;
 782         return retval;
 783 }
 784
 785
 786 /**
 787  *      usb_pcwd_disconnect
 788  *
 789  *      Called by the usb core when the device is removed from the system.
 790  *
 791  *      This routine guarantees that the driver will not submit any more urbs
 792  *      by clearing dev->udev.
 793  */
 794 static void usb_pcwd_disconnect(struct usb_interface *interface)
 795 {
 796         struct usb_pcwd_private *usb_pcwd;
 797
 798         /* prevent races with open() */
 799         mutex_lock(&disconnect_mutex);
 800
 801         usb_pcwd = usb_get_intfdata(interface);
 802         usb_set_intfdata(interface, NULL);
 803
 804         mutex_lock(&usb_pcwd->mtx);
 805
 806         /* Stop the timer before we leave */
 807         if (!nowayout)
 808                 usb_pcwd_stop(usb_pcwd);
 809
 810         /* We should now stop communicating with the USB PCWD device */
 811         usb_pcwd->exists = 0;
 812
 813         /* Deregister */
 814         misc_deregister(&usb_pcwd_miscdev);
 815         misc_deregister(&usb_pcwd_temperature_miscdev);
 816         unregister_reboot_notifier(&usb_pcwd_notifier);
 817
 818         mutex_unlock(&usb_pcwd->mtx);
 819
 820         /* Delete the USB PCWD device */
 821         usb_pcwd_delete(usb_pcwd);
 822
 823         cards_found--;
 824
 825         mutex_unlock(&disconnect_mutex);
 826
 827         pr_info("USB PC Watchdog disconnected\n");
 828 }
 829
 830 module_usb_driver(usb_pcwd_driver);