Pileus Git - ~andy/linux/blob - 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;
 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         buf = kmalloc(6, GFP_KERNEL);
 246         if (buf == NULL)
 247                 return 0;
 248
 249         /* The USB PC Watchdog uses a 6 byte report format.
 250          * The board currently uses only 3 of the six bytes of the report. */
 251         buf[0] = cmd;                   /* Byte 0 = CMD */
 252         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 253         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 254         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 255
 256         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 257                 buf[0], buf[1], buf[2]);
 258
 259         atomic_set(&usb_pcwd->cmd_received, 0);
 260
 261         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 262                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 263                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 264                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 265                 dbg("usb_pcwd_send_command: error in usb_control_msg for "
 266                                 "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 267         }
 268         /* wait till the usb card processed the command,
 269          * with a max. timeout of USB_COMMAND_TIMEOUT */
 270         got_response = 0;
 271         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
 272                                                                 count++) {
 273                 mdelay(1);
 274                 if (atomic_read(&usb_pcwd->cmd_received))
 275                         got_response = 1;
 276         }
 277
 278         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 279                 /* read back response */
 280                 *msb = usb_pcwd->cmd_data_msb;
 281                 *lsb = usb_pcwd->cmd_data_lsb;
 282         }
 283
 284         kfree(buf);
 285
 286         return got_response;
 287 }
 288
 289 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 290 {
 291         unsigned char msb = 0x00;
 292         unsigned char lsb = 0x00;
 293         int retval;
 294
 295         /* Enable Watchdog */
 296         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 297                                                                 &msb, &lsb);
 298
 299         if ((retval == 0) || (lsb == 0)) {
 300                 pr_err("Card did not acknowledge enable attempt\n");
 301                 return -1;
 302         }
 303
 304         return 0;
 305 }
 306
 307 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 308 {
 309         unsigned char msb = 0xA5;
 310         unsigned char lsb = 0xC3;
 311         int retval;
 312
 313         /* Disable Watchdog */
 314         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 315                                                                 &msb, &lsb);
 316
 317         if ((retval == 0) || (lsb != 0)) {
 318                 pr_err("Card did not acknowledge disable attempt\n");
 319                 return -1;
 320         }
 321
 322         return 0;
 323 }
 324
 325 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 326 {
 327         unsigned char dummy;
 328
 329         /* Re-trigger Watchdog */
 330         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 331
 332         return 0;
 333 }
 334
 335 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 336 {
 337         unsigned char msb = t / 256;
 338         unsigned char lsb = t % 256;
 339
 340         if ((t < 0x0001) || (t > 0xFFFF))
 341                 return -EINVAL;
 342
 343         /* Write new heartbeat to watchdog */
 344         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 345
 346         heartbeat = t;
 347         return 0;
 348 }
 349
 350 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 351                                                         int *temperature)
 352 {
 353         unsigned char msb, lsb;
 354
 355         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 356
 357         /*
 358          * Convert celsius to fahrenheit, since this was
 359          * the decided 'standard' for this return value.
 360          */
 361         *temperature = (lsb * 9 / 5) + 32;
 362
 363         return 0;
 364 }
 365
 366 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 367                                                                 int *time_left)
 368 {
 369         unsigned char msb, lsb;
 370
 371         /* Read the time that's left before rebooting */
 372         /* Note: if the board is not yet armed then we will read 0xFFFF */
 373         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 374
 375         *time_left = (msb << 8) + lsb;
 376
 377         return 0;
 378 }
 379
 380 /*
 381  *      /dev/watchdog handling
 382  */
 383
 384 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 385                                                 size_t len, loff_t *ppos)
 386 {
 387         /* See if we got the magic character 'V' and reload the timer */
 388         if (len) {
 389                 if (!nowayout) {
 390                         size_t i;
 391
 392                         /* note: just in case someone wrote the magic character
 393                          * five months ago... */
 394                         expect_release = 0;
 395
 396                         /* scan to see whether or not we got the
 397                          * magic character */
 398                         for (i = 0; i != len; i++) {
 399                                 char c;
 400                                 if (get_user(c, data + i))
 401                                         return -EFAULT;
 402                                 if (c == 'V')
 403                                         expect_release = 42;
 404                         }
 405                 }
 406
 407                 /* someone wrote to us, we should reload the timer */
 408                 usb_pcwd_keepalive(usb_pcwd_device);
 409         }
 410         return len;
 411 }
 412
 413 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 414                                                 unsigned long arg)
 415 {
 416         void __user *argp = (void __user *)arg;
 417         int __user *p = argp;
 418         static const struct watchdog_info ident = {
 419                 .options =              WDIOF_KEEPALIVEPING |
 420                                         WDIOF_SETTIMEOUT |
 421                                         WDIOF_MAGICCLOSE,
 422                 .firmware_version =     1,
 423                 .identity =             DRIVER_NAME,
 424         };
 425
 426         switch (cmd) {
 427         case WDIOC_GETSUPPORT:
 428                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 429
 430         case WDIOC_GETSTATUS:
 431         case WDIOC_GETBOOTSTATUS:
 432                 return put_user(0, p);
 433
 434         case WDIOC_GETTEMP:
 435         {
 436                 int temperature;
 437
 438                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 439                         return -EFAULT;
 440
 441                 return put_user(temperature, p);
 442         }
 443
 444         case WDIOC_SETOPTIONS:
 445         {
 446                 int new_options, retval = -EINVAL;
 447
 448                 if (get_user(new_options, p))
 449                         return -EFAULT;
 450
 451                 if (new_options & WDIOS_DISABLECARD) {
 452                         usb_pcwd_stop(usb_pcwd_device);
 453                         retval = 0;
 454                 }
 455
 456                 if (new_options & WDIOS_ENABLECARD) {
 457                         usb_pcwd_start(usb_pcwd_device);
 458                         retval = 0;
 459                 }
 460
 461                 return retval;
 462         }
 463
 464         case WDIOC_KEEPALIVE:
 465                 usb_pcwd_keepalive(usb_pcwd_device);
 466                 return 0;
 467
 468         case WDIOC_SETTIMEOUT:
 469         {
 470                 int new_heartbeat;
 471
 472                 if (get_user(new_heartbeat, p))
 473                         return -EFAULT;
 474
 475                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 476                         return -EINVAL;
 477
 478                 usb_pcwd_keepalive(usb_pcwd_device);
 479                 /* Fall */
 480         }
 481
 482         case WDIOC_GETTIMEOUT:
 483                 return put_user(heartbeat, p);
 484
 485         case WDIOC_GETTIMELEFT:
 486         {
 487                 int time_left;
 488
 489                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 490                         return -EFAULT;
 491
 492                 return put_user(time_left, p);
 493         }
 494
 495         default:
 496                 return -ENOTTY;
 497         }
 498 }
 499
 500 static int usb_pcwd_open(struct inode *inode, struct file *file)
 501 {
 502         /* /dev/watchdog can only be opened once */
 503         if (test_and_set_bit(0, &is_active))
 504                 return -EBUSY;
 505
 506         /* Activate */
 507         usb_pcwd_start(usb_pcwd_device);
 508         usb_pcwd_keepalive(usb_pcwd_device);
 509         return nonseekable_open(inode, file);
 510 }
 511
 512 static int usb_pcwd_release(struct inode *inode, struct file *file)
 513 {
 514         /*
 515          *      Shut off the timer.
 516          */
 517         if (expect_release == 42) {
 518                 usb_pcwd_stop(usb_pcwd_device);
 519         } else {
 520                 pr_crit("Unexpected close, not stopping watchdog!\n");
 521                 usb_pcwd_keepalive(usb_pcwd_device);
 522         }
 523         expect_release = 0;
 524         clear_bit(0, &is_active);
 525         return 0;
 526 }
 527
 528 /*
 529  *      /dev/temperature handling
 530  */
 531
 532 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 533                                 size_t len, loff_t *ppos)
 534 {
 535         int temperature;
 536
 537         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 538                 return -EFAULT;
 539
 540         if (copy_to_user(data, &temperature, 1))
 541                 return -EFAULT;
 542
 543         return 1;
 544 }
 545
 546 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 547 {
 548         return nonseekable_open(inode, file);
 549 }
 550
 551 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 552 {
 553         return 0;
 554 }
 555
 556 /*
 557  *      Notify system
 558  */
 559
 560 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 561                                                                 void *unused)
 562 {
 563         if (code == SYS_DOWN || code == SYS_HALT)
 564                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 565
 566         return NOTIFY_DONE;
 567 }
 568
 569 /*
 570  *      Kernel Interfaces
 571  */
 572
 573 static const struct file_operations usb_pcwd_fops = {
 574         .owner =        THIS_MODULE,
 575         .llseek =       no_llseek,
 576         .write =        usb_pcwd_write,
 577         .unlocked_ioctl = usb_pcwd_ioctl,
 578         .open =         usb_pcwd_open,
 579         .release =      usb_pcwd_release,
 580 };
 581
 582 static struct miscdevice usb_pcwd_miscdev = {
 583         .minor =        WATCHDOG_MINOR,
 584         .name =         "watchdog",
 585         .fops =         &usb_pcwd_fops,
 586 };
 587
 588 static const struct file_operations usb_pcwd_temperature_fops = {
 589         .owner =        THIS_MODULE,
 590         .llseek =       no_llseek,
 591         .read =         usb_pcwd_temperature_read,
 592         .open =         usb_pcwd_temperature_open,
 593         .release =      usb_pcwd_temperature_release,
 594 };
 595
 596 static struct miscdevice usb_pcwd_temperature_miscdev = {
 597         .minor =        TEMP_MINOR,
 598         .name =         "temperature",
 599         .fops =         &usb_pcwd_temperature_fops,
 600 };
 601
 602 static struct notifier_block usb_pcwd_notifier = {
 603         .notifier_call =        usb_pcwd_notify_sys,
 604 };
 605
 606 /**
 607  *      usb_pcwd_delete
 608  */
 609 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 610 {
 611         usb_free_urb(usb_pcwd->intr_urb);
 612         if (usb_pcwd->intr_buffer != NULL)
 613                 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 614                                   usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 615         kfree(usb_pcwd);
 616 }
 617
 618 /**
 619  *      usb_pcwd_probe
 620  *
 621  *      Called by the usb core when a new device is connected that it thinks
 622  *      this driver might be interested in.
 623  */
 624 static int usb_pcwd_probe(struct usb_interface *interface,
 625                                                 const struct usb_device_id *id)
 626 {
 627         struct usb_device *udev = interface_to_usbdev(interface);
 628         struct usb_host_interface *iface_desc;
 629         struct usb_endpoint_descriptor *endpoint;
 630         struct usb_pcwd_private *usb_pcwd = NULL;
 631         int pipe, maxp;
 632         int retval = -ENOMEM;
 633         int got_fw_rev;
 634         unsigned char fw_rev_major, fw_rev_minor;
 635         char fw_ver_str[20];
 636         unsigned char option_switches, dummy;
 637
 638         cards_found++;
 639         if (cards_found > 1) {
 640                 pr_err("This driver only supports 1 device\n");
 641                 return -ENODEV;
 642         }
 643
 644         /* get the active interface descriptor */
 645         iface_desc = interface->cur_altsetting;
 646
 647         /* check out that we have a HID device */
 648         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 649                 pr_err("The device isn't a Human Interface Device\n");
 650                 return -ENODEV;
 651         }
 652
 653         /* check out the endpoint: it has to be Interrupt & IN */
 654         endpoint = &iface_desc->endpoint[0].desc;
 655
 656         if (!usb_endpoint_is_int_in(endpoint)) {
 657                 /* we didn't find a Interrupt endpoint with direction IN */
 658                 pr_err("Couldn't find an INTR & IN endpoint\n");
 659                 return -ENODEV;
 660         }
 661
 662         /* get a handle to the interrupt data pipe */
 663         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 664         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 665
 666         /* allocate memory for our device and initialize it */
 667         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 668         if (usb_pcwd == NULL) {
 669                 pr_err("Out of memory\n");
 670                 goto error;
 671         }
 672
 673         usb_pcwd_device = usb_pcwd;
 674
 675         mutex_init(&usb_pcwd->mtx);
 676         usb_pcwd->udev = udev;
 677         usb_pcwd->interface = interface;
 678         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 679         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 680                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 681
 682         /* set up the memory buffer's */
 683         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 684                                         GFP_ATOMIC, &usb_pcwd->intr_dma);
 685         if (!usb_pcwd->intr_buffer) {
 686                 pr_err("Out of memory\n");
 687                 goto error;
 688         }
 689
 690         /* allocate the urb's */
 691         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 692         if (!usb_pcwd->intr_urb) {
 693                 pr_err("Out of memory\n");
 694                 goto error;
 695         }
 696
 697         /* initialise the intr urb's */
 698         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 699                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 700                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 701         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 702         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 703
 704         /* register our interrupt URB with the USB system */
 705         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 706                 pr_err("Problem registering interrupt URB\n");
 707                 retval = -EIO; /* failure */
 708                 goto error;
 709         }
 710
 711         /* The device exists and can be communicated with */
 712         usb_pcwd->exists = 1;
 713
 714         /* disable card */
 715         usb_pcwd_stop(usb_pcwd);
 716
 717         /* Get the Firmware Version */
 718         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 719                                                 &fw_rev_major, &fw_rev_minor);
 720         if (got_fw_rev)
 721                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 722         else
 723                 sprintf(fw_ver_str, "<card no answer>");
 724
 725         pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
 726
 727         /* Get switch settings */
 728         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 729                                                         &option_switches);
 730
 731         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 732                 option_switches,
 733                 ((option_switches & 0x10) ? "ON" : "OFF"),
 734                 ((option_switches & 0x08) ? "ON" : "OFF"));
 735
 736         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 737         if (heartbeat == 0)
 738                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 739
 740         /* Check that the heartbeat value is within it's range ;
 741          * if not reset to the default */
 742         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 743                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 744                 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
 745                         WATCHDOG_HEARTBEAT);
 746         }
 747
 748         retval = register_reboot_notifier(&usb_pcwd_notifier);
 749         if (retval != 0) {
 750                 pr_err("cannot register reboot notifier (err=%d)\n", retval);
 751                 goto error;
 752         }
 753
 754         retval = misc_register(&usb_pcwd_temperature_miscdev);
 755         if (retval != 0) {
 756                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 757                        TEMP_MINOR, retval);
 758                 goto err_out_unregister_reboot;
 759         }
 760
 761         retval = misc_register(&usb_pcwd_miscdev);
 762         if (retval != 0) {
 763                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 764                        WATCHDOG_MINOR, retval);
 765                 goto err_out_misc_deregister;
 766         }
 767
 768         /* we can register the device now, as it is ready */
 769         usb_set_intfdata(interface, usb_pcwd);
 770
 771         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 772                 heartbeat, nowayout);
 773
 774         return 0;
 775
 776 err_out_misc_deregister:
 777         misc_deregister(&usb_pcwd_temperature_miscdev);
 778 err_out_unregister_reboot:
 779         unregister_reboot_notifier(&usb_pcwd_notifier);
 780 error:
 781         if (usb_pcwd)
 782                 usb_pcwd_delete(usb_pcwd);
 783         usb_pcwd_device = NULL;
 784         return retval;
 785 }
 786
 787
 788 /**
 789  *      usb_pcwd_disconnect
 790  *
 791  *      Called by the usb core when the device is removed from the system.
 792  *
 793  *      This routine guarantees that the driver will not submit any more urbs
 794  *      by clearing dev->udev.
 795  */
 796 static void usb_pcwd_disconnect(struct usb_interface *interface)
 797 {
 798         struct usb_pcwd_private *usb_pcwd;
 799
 800         /* prevent races with open() */
 801         mutex_lock(&disconnect_mutex);
 802
 803         usb_pcwd = usb_get_intfdata(interface);
 804         usb_set_intfdata(interface, NULL);
 805
 806         mutex_lock(&usb_pcwd->mtx);
 807
 808         /* Stop the timer before we leave */
 809         if (!nowayout)
 810                 usb_pcwd_stop(usb_pcwd);
 811
 812         /* We should now stop communicating with the USB PCWD device */
 813         usb_pcwd->exists = 0;
 814
 815         /* Deregister */
 816         misc_deregister(&usb_pcwd_miscdev);
 817         misc_deregister(&usb_pcwd_temperature_miscdev);
 818         unregister_reboot_notifier(&usb_pcwd_notifier);
 819
 820         mutex_unlock(&usb_pcwd->mtx);
 821
 822         /* Delete the USB PCWD device */
 823         usb_pcwd_delete(usb_pcwd);
 824
 825         cards_found--;
 826
 827         mutex_unlock(&disconnect_mutex);
 828
 829         pr_info("USB PC Watchdog disconnected\n");
 830 }
 831
 832 module_usb_driver(usb_pcwd_driver);