drivers/watchdog/pcwd_usb.c

   1 /*
   2  *      Berkshire USB-PC Watchdog Card Driver
   3  *
   4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   5  *
   6  *      Based on source code of the following authors:
   7  *        Ken Hollis <kenji@bitgate.com>,
   8  *        Alan Cox <alan@redhat.com>,
   9  *        Matt Domsch <Matt_Domsch@dell.com>,
  10  *        Rob Radez <rob@osinvestor.com>,
  11  *        Greg Kroah-Hartman <greg@kroah.com>
  12  *
  13  *      This program is free software; you can redistribute it and/or
  14  *      modify it under the terms of the GNU General Public License
  15  *      as published by the Free Software Foundation; either version
  16  *      2 of the License, or (at your option) any later version.
  17  *
  18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  19  *      provide warranty for any of this software. This material is
  20  *      provided "AS-IS" and at no charge.
  21  *
  22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  23  *      providing the test hardware. More info is available at
  24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  25  */
  26
  27 #include <linux/module.h>       /* For module specific items */
  28 #include <linux/moduleparam.h>  /* For new moduleparam's */
  29 #include <linux/types.h>        /* For standard types (like size_t) */
  30 #include <linux/errno.h>        /* For the -ENODEV/... values */
  31 #include <linux/kernel.h>       /* For printk/panic/... */
  32 #include <linux/delay.h>        /* For mdelay function */
  33 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  34 #include <linux/watchdog.h>     /* For the watchdog specific items */
  35 #include <linux/notifier.h>     /* For notifier support */
  36 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  37 #include <linux/init.h>         /* For __init/__exit/... */
  38 #include <linux/fs.h>           /* For file operations */
  39 #include <linux/usb.h>          /* For USB functions */
  40 #include <linux/slab.h>         /* For kmalloc, ... */
  41 #include <linux/mutex.h>        /* For mutex locking */
  42 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  43
  44 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  45
  46
  47 #ifdef CONFIG_USB_DEBUG
  48         static int debug = 1;
  49 #else
  50         static int debug;
  51 #endif
  52
  53 /* Use our own dbg macro */
  54 #undef dbg
  55 #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
  56
  57
  58 /* Module and Version Information */
  59 #define DRIVER_VERSION "1.02"
  60 #define DRIVER_DATE "21 Jan 2007"
  61 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  62 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  63 #define DRIVER_LICENSE "GPL"
  64 #define DRIVER_NAME "pcwd_usb"
  65 #define PFX DRIVER_NAME ": "
  66
  67 MODULE_AUTHOR(DRIVER_AUTHOR);
  68 MODULE_DESCRIPTION(DRIVER_DESC);
  69 MODULE_LICENSE(DRIVER_LICENSE);
  70 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
  71 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
  72
  73 /* Module Parameters */
  74 module_param(debug, int, 0);
  75 MODULE_PARM_DESC(debug, "Debug enabled or not");
  76
  77 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat = delay-time from dip-switches */
  78 static int heartbeat = WATCHDOG_HEARTBEAT;
  79 module_param(heartbeat, int, 0);
  80 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  81
  82 static int nowayout = WATCHDOG_NOWAYOUT;
  83 module_param(nowayout, int, 0);
  84 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  85
  86 /* The vendor and product id's for the USB-PC Watchdog card */
  87 #define USB_PCWD_VENDOR_ID      0x0c98
  88 #define USB_PCWD_PRODUCT_ID     0x1140
  89
  90 /* table of devices that work with this driver */
  91 static struct usb_device_id usb_pcwd_table [] = {
  92         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  93         { }                                     /* Terminating entry */
  94 };
  95 MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
  96
  97 /* according to documentation max. time to process a command for the USB
  98  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
  99 #define USB_COMMAND_TIMEOUT     250
 100
 101 /* Watchdog's internal commands */
 102 #define CMD_READ_TEMP                   0x02    /* Read Temperature; Re-trigger Watchdog */
 103 #define CMD_TRIGGER                     CMD_READ_TEMP
 104 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
 105 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 106 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 107 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 108 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current Watchdog Time */
 109 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 110 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 111
 112 /* Watchdog's Dip Switch heartbeat values */
 113 static const int heartbeat_tbl [] = {
 114         5,      /* OFF-OFF-OFF  =  5 Sec  */
 115         10,     /* OFF-OFF-ON   = 10 Sec  */
 116         30,     /* OFF-ON-OFF   = 30 Sec  */
 117         60,     /* OFF-ON-ON    =  1 Min  */
 118         300,    /* ON-OFF-OFF   =  5 Min  */
 119         600,    /* ON-OFF-ON    = 10 Min  */
 120         1800,   /* ON-ON-OFF    = 30 Min  */
 121         3600,   /* ON-ON-ON     =  1 hour */
 122 };
 123
 124 /* We can only use 1 card due to the /dev/watchdog restriction */
 125 static int cards_found;
 126
 127 /* some internal variables */
 128 static unsigned long is_active;
 129 static char expect_release;
 130
 131 /* Structure to hold all of our device specific stuff */
 132 struct usb_pcwd_private {
 133         struct usb_device *     udev;                   /* save off the usb device pointer */
 134         struct usb_interface *  interface;              /* the interface for this device */
 135
 136         unsigned int            interface_number;       /* the interface number used for cmd's */
 137
 138         unsigned char *         intr_buffer;            /* the buffer to intr data */
 139         dma_addr_t              intr_dma;               /* the dma address for the intr buffer */
 140         size_t                  intr_size;              /* the size of the intr buffer */
 141         struct urb *            intr_urb;               /* the urb used for the intr pipe */
 142
 143         unsigned char           cmd_command;            /* The command that is reported back */
 144         unsigned char           cmd_data_msb;           /* The data MSB that is reported back */
 145         unsigned char           cmd_data_lsb;           /* The data LSB that is reported back */
 146         atomic_t                cmd_received;           /* true if we received a report after a command */
 147
 148         int                     exists;                 /* Wether or not the device exists */
 149         struct mutex            mtx;                    /* locks this structure */
 150 };
 151 static struct usb_pcwd_private *usb_pcwd_device;
 152
 153 /* prevent races between open() and disconnect() */
 154 static DEFINE_MUTEX(disconnect_mutex);
 155
 156 /* local function prototypes */
 157 static int usb_pcwd_probe       (struct usb_interface *interface, const struct usb_device_id *id);
 158 static void usb_pcwd_disconnect (struct usb_interface *interface);
 159
 160 /* usb specific object needed to register this driver with the usb subsystem */
 161 static struct usb_driver usb_pcwd_driver = {
 162         .name =         DRIVER_NAME,
 163         .probe =        usb_pcwd_probe,
 164         .disconnect =   usb_pcwd_disconnect,
 165         .id_table =     usb_pcwd_table,
 166 };
 167
 168
 169 static void usb_pcwd_intr_done(struct urb *urb)
 170 {
 171         struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
 172         unsigned char *data = usb_pcwd->intr_buffer;
 173         int retval;
 174
 175         switch (urb->status) {
 176         case 0:                 /* success */
 177                 break;
 178         case -ECONNRESET:       /* unlink */
 179         case -ENOENT:
 180         case -ESHUTDOWN:
 181                 /* this urb is terminated, clean up */
 182 <<<<<<< HEAD:drivers/watchdog/pcwd_usb.c
 183                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
 184 =======
 185                 dbg("%s - urb shutting down with status: %d", __func__, urb->status);
 186 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/watchdog/pcwd_usb.c
 187                 return;
 188         /* -EPIPE:  should clear the halt */
 189         default:                /* error */
 190 <<<<<<< HEAD:drivers/watchdog/pcwd_usb.c
 191                 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
 192 =======
 193                 dbg("%s - nonzero urb status received: %d", __func__, urb->status);
 194 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/watchdog/pcwd_usb.c
 195                 goto resubmit;
 196         }
 197
 198         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 199                 data[0], data[1], data[2]);
 200
 201         usb_pcwd->cmd_command  = data[0];
 202         usb_pcwd->cmd_data_msb = data[1];
 203         usb_pcwd->cmd_data_lsb = data[2];
 204
 205         /* notify anyone waiting that the cmd has finished */
 206         atomic_set (&usb_pcwd->cmd_received, 1);
 207
 208 resubmit:
 209         retval = usb_submit_urb (urb, GFP_ATOMIC);
 210         if (retval)
 211                 printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
 212                         retval);
 213 }
 214
 215 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
 216         unsigned char *msb, unsigned char *lsb)
 217 {
 218         int got_response, count;
 219         unsigned char buf[6];
 220
 221         /* We will not send any commands if the USB PCWD device does not exist */
 222         if ((!usb_pcwd) || (!usb_pcwd->exists))
 223                 return -1;
 224
 225         /* The USB PC Watchdog uses a 6 byte report format. The board currently uses
 226          * only 3 of the six bytes of the report. */
 227         buf[0] = cmd;                   /* Byte 0 = CMD */
 228         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 229         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 230         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 231
 232         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 233                 buf[0], buf[1], buf[2]);
 234
 235         atomic_set (&usb_pcwd->cmd_received, 0);
 236
 237         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 238                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 239                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 240                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 241                 dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 242         }
 243         /* wait till the usb card processed the command,
 244          * with a max. timeout of USB_COMMAND_TIMEOUT */
 245         got_response = 0;
 246         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
 247                 mdelay(1);
 248                 if (atomic_read (&usb_pcwd->cmd_received))
 249                         got_response = 1;
 250         }
 251
 252         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 253                 /* read back response */
 254                 *msb = usb_pcwd->cmd_data_msb;
 255                 *lsb = usb_pcwd->cmd_data_lsb;
 256         }
 257
 258         return got_response;
 259 }
 260
 261 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 262 {
 263         unsigned char msb = 0x00;
 264         unsigned char lsb = 0x00;
 265         int retval;
 266
 267         /* Enable Watchdog */
 268         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
 269
 270         if ((retval == 0) || (lsb == 0)) {
 271                 printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
 272                 return -1;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 279 {
 280         unsigned char msb = 0xA5;
 281         unsigned char lsb = 0xC3;
 282         int retval;
 283
 284         /* Disable Watchdog */
 285         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
 286
 287         if ((retval == 0) || (lsb != 0)) {
 288                 printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
 289                 return -1;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 296 {
 297         unsigned char dummy;
 298
 299         /* Re-trigger Watchdog */
 300         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 301
 302         return 0;
 303 }
 304
 305 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 306 {
 307         unsigned char msb = t / 256;
 308         unsigned char lsb = t % 256;
 309
 310         if ((t < 0x0001) || (t > 0xFFFF))
 311                 return -EINVAL;
 312
 313         /* Write new heartbeat to watchdog */
 314         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 315
 316         heartbeat = t;
 317         return 0;
 318 }
 319
 320 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
 321 {
 322         unsigned char msb, lsb;
 323
 324         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 325
 326         /*
 327          * Convert celsius to fahrenheit, since this was
 328          * the decided 'standard' for this return value.
 329          */
 330         *temperature = (lsb * 9 / 5) + 32;
 331
 332         return 0;
 333 }
 334
 335 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left)
 336 {
 337         unsigned char msb, lsb;
 338
 339         /* Read the time that's left before rebooting */
 340         /* Note: if the board is not yet armed then we will read 0xFFFF */
 341         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 342
 343         *time_left = (msb << 8) + lsb;
 344
 345         return 0;
 346 }
 347
 348 /*
 349  *      /dev/watchdog handling
 350  */
 351
 352 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 353                               size_t len, loff_t *ppos)
 354 {
 355         /* See if we got the magic character 'V' and reload the timer */
 356         if (len) {
 357                 if (!nowayout) {
 358                         size_t i;
 359
 360                         /* note: just in case someone wrote the magic character
 361                          * five months ago... */
 362                         expect_release = 0;
 363
 364                         /* scan to see whether or not we got the magic character */
 365                         for (i = 0; i != len; i++) {
 366                                 char c;
 367                                 if(get_user(c, data+i))
 368                                         return -EFAULT;
 369                                 if (c == 'V')
 370                                         expect_release = 42;
 371                         }
 372                 }
 373
 374                 /* someone wrote to us, we should reload the timer */
 375                 usb_pcwd_keepalive(usb_pcwd_device);
 376         }
 377         return len;
 378 }
 379
 380 static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
 381                           unsigned int cmd, unsigned long arg)
 382 {
 383         void __user *argp = (void __user *)arg;
 384         int __user *p = argp;
 385         static struct watchdog_info ident = {
 386                 .options =              WDIOF_KEEPALIVEPING |
 387                                         WDIOF_SETTIMEOUT |
 388                                         WDIOF_MAGICCLOSE,
 389                 .firmware_version =     1,
 390                 .identity =             DRIVER_NAME,
 391         };
 392
 393         switch (cmd) {
 394                 case WDIOC_GETSUPPORT:
 395                         return copy_to_user(argp, &ident,
 396                                 sizeof (ident)) ? -EFAULT : 0;
 397
 398                 case WDIOC_GETSTATUS:
 399                 case WDIOC_GETBOOTSTATUS:
 400                         return put_user(0, p);
 401
 402                 case WDIOC_GETTEMP:
 403                 {
 404                         int temperature;
 405
 406                         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 407                                 return -EFAULT;
 408
 409                         return put_user(temperature, p);
 410                 }
 411
 412                 case WDIOC_KEEPALIVE:
 413                         usb_pcwd_keepalive(usb_pcwd_device);
 414                         return 0;
 415
 416                 case WDIOC_SETOPTIONS:
 417                 {
 418                         int new_options, retval = -EINVAL;
 419
 420                         if (get_user (new_options, p))
 421                                 return -EFAULT;
 422
 423                         if (new_options & WDIOS_DISABLECARD) {
 424                                 usb_pcwd_stop(usb_pcwd_device);
 425                                 retval = 0;
 426                         }
 427
 428                         if (new_options & WDIOS_ENABLECARD) {
 429                                 usb_pcwd_start(usb_pcwd_device);
 430                                 retval = 0;
 431                         }
 432
 433                         return retval;
 434                 }
 435
 436                 case WDIOC_SETTIMEOUT:
 437                 {
 438                         int new_heartbeat;
 439
 440                         if (get_user(new_heartbeat, p))
 441                                 return -EFAULT;
 442
 443                         if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 444                             return -EINVAL;
 445
 446                         usb_pcwd_keepalive(usb_pcwd_device);
 447                         /* Fall */
 448                 }
 449
 450                 case WDIOC_GETTIMEOUT:
 451                         return put_user(heartbeat, p);
 452
 453                 case WDIOC_GETTIMELEFT:
 454                 {
 455                         int time_left;
 456
 457                         if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 458                                 return -EFAULT;
 459
 460                         return put_user(time_left, p);
 461                 }
 462
 463                 default:
 464                         return -ENOTTY;
 465         }
 466 }
 467
 468 static int usb_pcwd_open(struct inode *inode, struct file *file)
 469 {
 470         /* /dev/watchdog can only be opened once */
 471         if (test_and_set_bit(0, &is_active))
 472                 return -EBUSY;
 473
 474         /* Activate */
 475         usb_pcwd_start(usb_pcwd_device);
 476         usb_pcwd_keepalive(usb_pcwd_device);
 477         return nonseekable_open(inode, file);
 478 }
 479
 480 static int usb_pcwd_release(struct inode *inode, struct file *file)
 481 {
 482         /*
 483          *      Shut off the timer.
 484          */
 485         if (expect_release == 42) {
 486                 usb_pcwd_stop(usb_pcwd_device);
 487         } else {
 488                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 489                 usb_pcwd_keepalive(usb_pcwd_device);
 490         }
 491         expect_release = 0;
 492         clear_bit(0, &is_active);
 493         return 0;
 494 }
 495
 496 /*
 497  *      /dev/temperature handling
 498  */
 499
 500 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 501                                 size_t len, loff_t *ppos)
 502 {
 503         int temperature;
 504
 505         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 506                 return -EFAULT;
 507
 508         if (copy_to_user(data, &temperature, 1))
 509                 return -EFAULT;
 510
 511         return 1;
 512 }
 513
 514 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 515 {
 516         return nonseekable_open(inode, file);
 517 }
 518
 519 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 520 {
 521         return 0;
 522 }
 523
 524 /*
 525  *      Notify system
 526  */
 527
 528 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 529 {
 530         if (code==SYS_DOWN || code==SYS_HALT) {
 531                 /* Turn the WDT off */
 532                 usb_pcwd_stop(usb_pcwd_device);
 533         }
 534
 535         return NOTIFY_DONE;
 536 }
 537
 538 /*
 539  *      Kernel Interfaces
 540  */
 541
 542 static const struct file_operations usb_pcwd_fops = {
 543         .owner =        THIS_MODULE,
 544         .llseek =       no_llseek,
 545         .write =        usb_pcwd_write,
 546         .ioctl =        usb_pcwd_ioctl,
 547         .open =         usb_pcwd_open,
 548         .release =      usb_pcwd_release,
 549 };
 550
 551 static struct miscdevice usb_pcwd_miscdev = {
 552         .minor =        WATCHDOG_MINOR,
 553         .name =         "watchdog",
 554         .fops =         &usb_pcwd_fops,
 555 };
 556
 557 static const struct file_operations usb_pcwd_temperature_fops = {
 558         .owner =        THIS_MODULE,
 559         .llseek =       no_llseek,
 560         .read =         usb_pcwd_temperature_read,
 561         .open =         usb_pcwd_temperature_open,
 562         .release =      usb_pcwd_temperature_release,
 563 };
 564
 565 static struct miscdevice usb_pcwd_temperature_miscdev = {
 566         .minor =        TEMP_MINOR,
 567         .name =         "temperature",
 568         .fops =         &usb_pcwd_temperature_fops,
 569 };
 570
 571 static struct notifier_block usb_pcwd_notifier = {
 572         .notifier_call =        usb_pcwd_notify_sys,
 573 };
 574
 575 /**
 576  *      usb_pcwd_delete
 577  */
 578 static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
 579 {
 580         usb_free_urb(usb_pcwd->intr_urb);
 581         if (usb_pcwd->intr_buffer != NULL)
 582                 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
 583                                 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 584         kfree (usb_pcwd);
 585 }
 586
 587 /**
 588  *      usb_pcwd_probe
 589  *
 590  *      Called by the usb core when a new device is connected that it thinks
 591  *      this driver might be interested in.
 592  */
 593 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
 594 {
 595         struct usb_device *udev = interface_to_usbdev(interface);
 596         struct usb_host_interface *iface_desc;
 597         struct usb_endpoint_descriptor *endpoint;
 598         struct usb_pcwd_private *usb_pcwd = NULL;
 599         int pipe, maxp;
 600         int retval = -ENOMEM;
 601         int got_fw_rev;
 602         unsigned char fw_rev_major, fw_rev_minor;
 603         char fw_ver_str[20];
 604         unsigned char option_switches, dummy;
 605
 606         cards_found++;
 607         if (cards_found > 1) {
 608                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 609                 return -ENODEV;
 610         }
 611
 612         /* get the active interface descriptor */
 613         iface_desc = interface->cur_altsetting;
 614
 615         /* check out that we have a HID device */
 616         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 617                 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
 618                 return -ENODEV;
 619         }
 620
 621         /* check out the endpoint: it has to be Interrupt & IN */
 622         endpoint = &iface_desc->endpoint[0].desc;
 623
 624         if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
 625              ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
 626                                 == USB_ENDPOINT_XFER_INT))) {
 627                 /* we didn't find a Interrupt endpoint with direction IN */
 628                 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 629                 return -ENODEV;
 630         }
 631
 632         /* get a handle to the interrupt data pipe */
 633         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 634         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 635
 636         /* allocate memory for our device and initialize it */
 637         usb_pcwd = kzalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
 638         if (usb_pcwd == NULL) {
 639                 printk(KERN_ERR PFX "Out of memory\n");
 640                 goto error;
 641         }
 642
 643         usb_pcwd_device = usb_pcwd;
 644
 645         mutex_init(&usb_pcwd->mtx);
 646         usb_pcwd->udev = udev;
 647         usb_pcwd->interface = interface;
 648         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 649         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 650
 651         /* set up the memory buffer's */
 652         if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma))) {
 653                 printk(KERN_ERR PFX "Out of memory\n");
 654                 goto error;
 655         }
 656
 657         /* allocate the urb's */
 658         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 659         if (!usb_pcwd->intr_urb) {
 660                 printk(KERN_ERR PFX "Out of memory\n");
 661                 goto error;
 662         }
 663
 664         /* initialise the intr urb's */
 665         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 666                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 667                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 668         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 669         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 670
 671         /* register our interrupt URB with the USB system */
 672         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 673                 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 674                 retval = -EIO; /* failure */
 675                 goto error;
 676         }
 677
 678         /* The device exists and can be communicated with */
 679         usb_pcwd->exists = 1;
 680
 681         /* disable card */
 682         usb_pcwd_stop(usb_pcwd);
 683
 684         /* Get the Firmware Version */
 685         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
 686         if (got_fw_rev) {
 687                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 688         } else {
 689                 sprintf(fw_ver_str, "<card no answer>");
 690         }
 691
 692         printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 693                 fw_ver_str);
 694
 695         /* Get switch settings */
 696         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
 697
 698         printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 699                 option_switches,
 700                 ((option_switches & 0x10) ? "ON" : "OFF"),
 701                 ((option_switches & 0x08) ? "ON" : "OFF"));
 702
 703         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 704         if (heartbeat == 0)
 705                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 706
 707         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 708         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 709                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 710                 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
 711                         WATCHDOG_HEARTBEAT);
 712         }
 713
 714         retval = register_reboot_notifier(&usb_pcwd_notifier);
 715         if (retval != 0) {
 716                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 717                         retval);
 718                 goto error;
 719         }
 720
 721         retval = misc_register(&usb_pcwd_temperature_miscdev);
 722         if (retval != 0) {
 723                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 724                         TEMP_MINOR, retval);
 725                 goto err_out_unregister_reboot;
 726         }
 727
 728         retval = misc_register(&usb_pcwd_miscdev);
 729         if (retval != 0) {
 730                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 731                         WATCHDOG_MINOR, retval);
 732                 goto err_out_misc_deregister;
 733         }
 734
 735         /* we can register the device now, as it is ready */
 736         usb_set_intfdata (interface, usb_pcwd);
 737
 738         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 739                 heartbeat, nowayout);
 740
 741         return 0;
 742
 743 err_out_misc_deregister:
 744         misc_deregister(&usb_pcwd_temperature_miscdev);
 745 err_out_unregister_reboot:
 746         unregister_reboot_notifier(&usb_pcwd_notifier);
 747 error:
 748         if (usb_pcwd)
 749                 usb_pcwd_delete(usb_pcwd);
 750         usb_pcwd_device = NULL;
 751         return retval;
 752 }
 753
 754
 755 /**
 756  *      usb_pcwd_disconnect
 757  *
 758  *      Called by the usb core when the device is removed from the system.
 759  *
 760  *      This routine guarantees that the driver will not submit any more urbs
 761  *      by clearing dev->udev.
 762  */
 763 static void usb_pcwd_disconnect(struct usb_interface *interface)
 764 {
 765         struct usb_pcwd_private *usb_pcwd;
 766
 767         /* prevent races with open() */
 768         mutex_lock(&disconnect_mutex);
 769
 770         usb_pcwd = usb_get_intfdata (interface);
 771         usb_set_intfdata (interface, NULL);
 772
 773         mutex_lock(&usb_pcwd->mtx);
 774
 775         /* Stop the timer before we leave */
 776         if (!nowayout)
 777                 usb_pcwd_stop(usb_pcwd);
 778
 779         /* We should now stop communicating with the USB PCWD device */
 780         usb_pcwd->exists = 0;
 781
 782         /* Deregister */
 783         misc_deregister(&usb_pcwd_miscdev);
 784         misc_deregister(&usb_pcwd_temperature_miscdev);
 785         unregister_reboot_notifier(&usb_pcwd_notifier);
 786
 787         mutex_unlock(&usb_pcwd->mtx);
 788
 789         /* Delete the USB PCWD device */
 790         usb_pcwd_delete(usb_pcwd);
 791
 792         cards_found--;
 793
 794         mutex_unlock(&disconnect_mutex);
 795
 796         printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 797 }
 798
 799
 800
 801 /**
 802  *      usb_pcwd_init
 803  */
 804 static int __init usb_pcwd_init(void)
 805 {
 806         int result;
 807
 808         /* register this driver with the USB subsystem */
 809         result = usb_register(&usb_pcwd_driver);
 810         if (result) {
 811                 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
 812                     result);
 813                 return result;
 814         }
 815
 816         printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
 817         return 0;
 818 }
 819
 820
 821 /**
 822  *      usb_pcwd_exit
 823  */
 824 static void __exit usb_pcwd_exit(void)
 825 {
 826         /* deregister this driver with the USB subsystem */
 827         usb_deregister(&usb_pcwd_driver);
 828 }
 829
 830
 831 module_init (usb_pcwd_init);
 832 module_exit (usb_pcwd_exit);