drivers/watchdog/pcwd_usb.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *      Berkshire USB-PC Watchdog Card Driver
   4  *
   5  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
   6  *
   7  *      Based on source code of the following authors:
   8  *        Ken Hollis <kenji@bitgate.com>,
   9  *        Alan Cox <alan@lxorguk.ukuu.org.uk>,
  10  *        Matt Domsch <Matt_Domsch@dell.com>,
  11  *        Rob Radez <rob@osinvestor.com>,
  12  *        Greg Kroah-Hartman <greg@kroah.com>
  13  *
  14  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  15  *      provide warranty for any of this software. This material is
  16  *      provided "AS-IS" and at no charge.
  17  *
  18  *      Thanks also to Simon Machell at Berkshire Products Inc. for
  19  *      providing the test hardware. More info is available at
  20  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/module.h>       /* For module specific items */
  26 #include <linux/moduleparam.h>  /* For new moduleparam's */
  27 #include <linux/types.h>        /* For standard types (like size_t) */
  28 #include <linux/errno.h>        /* For the -ENODEV/... values */
  29 #include <linux/kernel.h>       /* For printk/panic/... */
  30 #include <linux/delay.h>        /* For mdelay function */
  31 #include <linux/miscdevice.h>   /* For struct miscdevice */
  32 #include <linux/watchdog.h>     /* For the watchdog specific items */
  33 #include <linux/notifier.h>     /* For notifier support */
  34 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  35 #include <linux/init.h>         /* For __init/__exit/... */
  36 #include <linux/fs.h>           /* For file operations */
  37 #include <linux/usb.h>          /* For USB functions */
  38 #include <linux/slab.h>         /* For kmalloc, ... */
  39 #include <linux/mutex.h>        /* For mutex locking */
  40 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
  41 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  42
  43
  44 /* Module and Version Information */
  45 #define DRIVER_VERSION "1.02"
  46 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  47 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  48 #define DRIVER_NAME "pcwd_usb"
  49
  50 MODULE_AUTHOR(DRIVER_AUTHOR);
  51 MODULE_DESCRIPTION(DRIVER_DESC);
  52 MODULE_LICENSE("GPL");
  53
  54 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
  55                                                 delay-time from dip-switches */
  56 static int heartbeat = WATCHDOG_HEARTBEAT;
  57 module_param(heartbeat, int, 0);
  58 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
  59         "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
  60                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  61
  62 static bool nowayout = WATCHDOG_NOWAYOUT;
  63 module_param(nowayout, bool, 0);
  64 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  65                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  66
  67 /* The vendor and product id's for the USB-PC Watchdog card */
  68 #define USB_PCWD_VENDOR_ID      0x0c98
  69 #define USB_PCWD_PRODUCT_ID     0x1140
  70
  71 /* table of devices that work with this driver */
  72 static const struct usb_device_id usb_pcwd_table[] = {
  73         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  74         { }                                     /* Terminating entry */
  75 };
  76 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
  77
  78 /* according to documentation max. time to process a command for the USB
  79  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
  80 #define USB_COMMAND_TIMEOUT     250
  81
  82 /* Watchdog's internal commands */
  83 #define CMD_READ_TEMP                   0x02    /* Read Temperature;
  84                                                         Re-trigger Watchdog */
  85 #define CMD_TRIGGER                     CMD_READ_TEMP
  86 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
  87 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
  88 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
  89 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
  90 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
  91 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
  92 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
  93
  94 /* Watchdog's Dip Switch heartbeat values */
  95 static const int heartbeat_tbl[] = {
  96         5,      /* OFF-OFF-OFF  =  5 Sec  */
  97         10,     /* OFF-OFF-ON   = 10 Sec  */
  98         30,     /* OFF-ON-OFF   = 30 Sec  */
  99         60,     /* OFF-ON-ON    =  1 Min  */
 100         300,    /* ON-OFF-OFF   =  5 Min  */
 101         600,    /* ON-OFF-ON    = 10 Min  */
 102         1800,   /* ON-ON-OFF    = 30 Min  */
 103         3600,   /* ON-ON-ON     =  1 hour */
 104 };
 105
 106 /* We can only use 1 card due to the /dev/watchdog restriction */
 107 static int cards_found;
 108
 109 /* some internal variables */
 110 static unsigned long is_active;
 111 static char expect_release;
 112
 113 /* Structure to hold all of our device specific stuff */
 114 struct usb_pcwd_private {
 115         /* save off the usb device pointer */
 116         struct usb_device       *udev;
 117         /* the interface for this device */
 118         struct usb_interface    *interface;
 119
 120         /* the interface number used for cmd's */
 121         unsigned int            interface_number;
 122
 123         /* the buffer to intr data */
 124         unsigned char           *intr_buffer;
 125         /* the dma address for the intr buffer */
 126         dma_addr_t              intr_dma;
 127         /* the size of the intr buffer */
 128         size_t                  intr_size;
 129         /* the urb used for the intr pipe */
 130         struct urb              *intr_urb;
 131
 132         /* The command that is reported back */
 133         unsigned char           cmd_command;
 134         /* The data MSB that is reported back */
 135         unsigned char           cmd_data_msb;
 136         /* The data LSB that is reported back */
 137         unsigned char           cmd_data_lsb;
 138         /* true if we received a report after a command */
 139         atomic_t                cmd_received;
 140
 141         /* Wether or not the device exists */
 142         int                     exists;
 143         /* locks this structure */
 144         struct mutex            mtx;
 145 };
 146 static struct usb_pcwd_private *usb_pcwd_device;
 147
 148 /* prevent races between open() and disconnect() */
 149 static DEFINE_MUTEX(disconnect_mutex);
 150
 151 /* local function prototypes */
 152 static int usb_pcwd_probe(struct usb_interface *interface,
 153                                                 const struct usb_device_id *id);
 154 static void usb_pcwd_disconnect(struct usb_interface *interface);
 155
 156 /* usb specific object needed to register this driver with the usb subsystem */
 157 static struct usb_driver usb_pcwd_driver = {
 158         .name =         DRIVER_NAME,
 159         .probe =        usb_pcwd_probe,
 160         .disconnect =   usb_pcwd_disconnect,
 161         .id_table =     usb_pcwd_table,
 162 };
 163
 164
 165 static void usb_pcwd_intr_done(struct urb *urb)
 166 {
 167         struct usb_pcwd_private *usb_pcwd =
 168                                 (struct usb_pcwd_private *)urb->context;
 169         unsigned char *data = usb_pcwd->intr_buffer;
 170         struct device *dev = &usb_pcwd->interface->dev;
 171         int retval;
 172
 173         switch (urb->status) {
 174         case 0:                 /* success */
 175                 break;
 176         case -ECONNRESET:       /* unlink */
 177         case -ENOENT:
 178         case -ESHUTDOWN:
 179                 /* this urb is terminated, clean up */
 180                 dev_dbg(dev, "%s - urb shutting down with status: %d",
 181                         __func__, urb->status);
 182                 return;
 183         /* -EPIPE:  should clear the halt */
 184         default:                /* error */
 185                 dev_dbg(dev, "%s - nonzero urb status received: %d",
 186                         __func__, urb->status);
 187                 goto resubmit;
 188         }
 189
 190         dev_dbg(dev, "received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 191                 data[0], data[1], data[2]);
 192
 193         usb_pcwd->cmd_command  = data[0];
 194         usb_pcwd->cmd_data_msb = data[1];
 195         usb_pcwd->cmd_data_lsb = data[2];
 196
 197         /* notify anyone waiting that the cmd has finished */
 198         atomic_set(&usb_pcwd->cmd_received, 1);
 199
 200 resubmit:
 201         retval = usb_submit_urb(urb, GFP_ATOMIC);
 202         if (retval)
 203                 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
 204                        retval);
 205 }
 206
 207 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 208                 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 209 {
 210         int got_response, count;
 211         unsigned char *buf;
 212
 213         /* We will not send any commands if the USB PCWD device does
 214          * not exist */
 215         if ((!usb_pcwd) || (!usb_pcwd->exists))
 216                 return -1;
 217
 218         buf = kmalloc(6, GFP_KERNEL);
 219         if (buf == NULL)
 220                 return 0;
 221
 222         /* The USB PC Watchdog uses a 6 byte report format.
 223          * The board currently uses only 3 of the six bytes of the report. */
 224         buf[0] = cmd;                   /* Byte 0 = CMD */
 225         buf[1] = *msb;                  /* Byte 1 = Data MSB */
 226         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 227         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 228
 229         dev_dbg(&usb_pcwd->interface->dev,
 230                 "sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 231                 buf[0], buf[1], buf[2]);
 232
 233         atomic_set(&usb_pcwd->cmd_received, 0);
 234
 235         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 236                         HID_REQ_SET_REPORT, HID_DT_REPORT,
 237                         0x0200, usb_pcwd->interface_number, buf, 6,
 238                         USB_COMMAND_TIMEOUT) != 6) {
 239                 dev_dbg(&usb_pcwd->interface->dev,
 240                         "usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n",
 241                         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);
 247                                                                 count++) {
 248                 mdelay(1);
 249                 if (atomic_read(&usb_pcwd->cmd_received))
 250                         got_response = 1;
 251         }
 252
 253         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 254                 /* read back response */
 255                 *msb = usb_pcwd->cmd_data_msb;
 256                 *lsb = usb_pcwd->cmd_data_lsb;
 257         }
 258
 259         kfree(buf);
 260
 261         return got_response;
 262 }
 263
 264 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 265 {
 266         unsigned char msb = 0x00;
 267         unsigned char lsb = 0x00;
 268         int retval;
 269
 270         /* Enable Watchdog */
 271         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 272                                                                 &msb, &lsb);
 273
 274         if ((retval == 0) || (lsb == 0)) {
 275                 pr_err("Card did not acknowledge enable attempt\n");
 276                 return -1;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 283 {
 284         unsigned char msb = 0xA5;
 285         unsigned char lsb = 0xC3;
 286         int retval;
 287
 288         /* Disable Watchdog */
 289         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 290                                                                 &msb, &lsb);
 291
 292         if ((retval == 0) || (lsb != 0)) {
 293                 pr_err("Card did not acknowledge disable attempt\n");
 294                 return -1;
 295         }
 296
 297         return 0;
 298 }
 299
 300 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 301 {
 302         unsigned char dummy;
 303
 304         /* Re-trigger Watchdog */
 305         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 306
 307         return 0;
 308 }
 309
 310 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 311 {
 312         unsigned char msb = t / 256;
 313         unsigned char lsb = t % 256;
 314
 315         if ((t < 0x0001) || (t > 0xFFFF))
 316                 return -EINVAL;
 317
 318         /* Write new heartbeat to watchdog */
 319         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 320
 321         heartbeat = t;
 322         return 0;
 323 }
 324
 325 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 326                                                         int *temperature)
 327 {
 328         unsigned char msb, lsb;
 329
 330         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 331
 332         /*
 333          * Convert celsius to fahrenheit, since this was
 334          * the decided 'standard' for this return value.
 335          */
 336         *temperature = (lsb * 9 / 5) + 32;
 337
 338         return 0;
 339 }
 340
 341 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 342                                                                 int *time_left)
 343 {
 344         unsigned char msb, lsb;
 345
 346         /* Read the time that's left before rebooting */
 347         /* Note: if the board is not yet armed then we will read 0xFFFF */
 348         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 349
 350         *time_left = (msb << 8) + lsb;
 351
 352         return 0;
 353 }
 354
 355 /*
 356  *      /dev/watchdog handling
 357  */
 358
 359 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 360                                                 size_t len, loff_t *ppos)
 361 {
 362         /* See if we got the magic character 'V' and reload the timer */
 363         if (len) {
 364                 if (!nowayout) {
 365                         size_t i;
 366
 367                         /* note: just in case someone wrote the magic character
 368                          * five months ago... */
 369                         expect_release = 0;
 370
 371                         /* scan to see whether or not we got the
 372                          * magic character */
 373                         for (i = 0; i != len; i++) {
 374                                 char c;
 375                                 if (get_user(c, data + i))
 376                                         return -EFAULT;
 377                                 if (c == 'V')
 378                                         expect_release = 42;
 379                         }
 380                 }
 381
 382                 /* someone wrote to us, we should reload the timer */
 383                 usb_pcwd_keepalive(usb_pcwd_device);
 384         }
 385         return len;
 386 }
 387
 388 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 389                                                 unsigned long arg)
 390 {
 391         void __user *argp = (void __user *)arg;
 392         int __user *p = argp;
 393         static const struct watchdog_info ident = {
 394                 .options =              WDIOF_KEEPALIVEPING |
 395                                         WDIOF_SETTIMEOUT |
 396                                         WDIOF_MAGICCLOSE,
 397                 .firmware_version =     1,
 398                 .identity =             DRIVER_NAME,
 399         };
 400
 401         switch (cmd) {
 402         case WDIOC_GETSUPPORT:
 403                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 404
 405         case WDIOC_GETSTATUS:
 406         case WDIOC_GETBOOTSTATUS:
 407                 return put_user(0, p);
 408
 409         case WDIOC_GETTEMP:
 410         {
 411                 int temperature;
 412
 413                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 414                         return -EFAULT;
 415
 416                 return put_user(temperature, p);
 417         }
 418
 419         case WDIOC_SETOPTIONS:
 420         {
 421                 int new_options, retval = -EINVAL;
 422
 423                 if (get_user(new_options, p))
 424                         return -EFAULT;
 425
 426                 if (new_options & WDIOS_DISABLECARD) {
 427                         usb_pcwd_stop(usb_pcwd_device);
 428                         retval = 0;
 429                 }
 430
 431                 if (new_options & WDIOS_ENABLECARD) {
 432                         usb_pcwd_start(usb_pcwd_device);
 433                         retval = 0;
 434                 }
 435
 436                 return retval;
 437         }
 438
 439         case WDIOC_KEEPALIVE:
 440                 usb_pcwd_keepalive(usb_pcwd_device);
 441                 return 0;
 442
 443         case WDIOC_SETTIMEOUT:
 444         {
 445                 int new_heartbeat;
 446
 447                 if (get_user(new_heartbeat, p))
 448                         return -EFAULT;
 449
 450                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 451                         return -EINVAL;
 452
 453                 usb_pcwd_keepalive(usb_pcwd_device);
 454         }
 455                 fallthrough;
 456
 457         case WDIOC_GETTIMEOUT:
 458                 return put_user(heartbeat, p);
 459
 460         case WDIOC_GETTIMELEFT:
 461         {
 462                 int time_left;
 463
 464                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 465                         return -EFAULT;
 466
 467                 return put_user(time_left, p);
 468         }
 469
 470         default:
 471                 return -ENOTTY;
 472         }
 473 }
 474
 475 static int usb_pcwd_open(struct inode *inode, struct file *file)
 476 {
 477         /* /dev/watchdog can only be opened once */
 478         if (test_and_set_bit(0, &is_active))
 479                 return -EBUSY;
 480
 481         /* Activate */
 482         usb_pcwd_start(usb_pcwd_device);
 483         usb_pcwd_keepalive(usb_pcwd_device);
 484         return stream_open(inode, file);
 485 }
 486
 487 static int usb_pcwd_release(struct inode *inode, struct file *file)
 488 {
 489         /*
 490          *      Shut off the timer.
 491          */
 492         if (expect_release == 42) {
 493                 usb_pcwd_stop(usb_pcwd_device);
 494         } else {
 495                 pr_crit("Unexpected close, not stopping watchdog!\n");
 496                 usb_pcwd_keepalive(usb_pcwd_device);
 497         }
 498         expect_release = 0;
 499         clear_bit(0, &is_active);
 500         return 0;
 501 }
 502
 503 /*
 504  *      /dev/temperature handling
 505  */
 506
 507 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 508                                 size_t len, loff_t *ppos)
 509 {
 510         int temperature;
 511
 512         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 513                 return -EFAULT;
 514
 515         if (copy_to_user(data, &temperature, 1))
 516                 return -EFAULT;
 517
 518         return 1;
 519 }
 520
 521 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 522 {
 523         return stream_open(inode, file);
 524 }
 525
 526 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 527 {
 528         return 0;
 529 }
 530
 531 /*
 532  *      Notify system
 533  */
 534
 535 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 536                                                                 void *unused)
 537 {
 538         if (code == SYS_DOWN || code == SYS_HALT)
 539                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 540
 541         return NOTIFY_DONE;
 542 }
 543
 544 /*
 545  *      Kernel Interfaces
 546  */
 547
 548 static const struct file_operations usb_pcwd_fops = {
 549         .owner =        THIS_MODULE,
 550         .llseek =       no_llseek,
 551         .write =        usb_pcwd_write,
 552         .unlocked_ioctl = usb_pcwd_ioctl,
 553         .compat_ioctl = compat_ptr_ioctl,
 554         .open =         usb_pcwd_open,
 555         .release =      usb_pcwd_release,
 556 };
 557
 558 static struct miscdevice usb_pcwd_miscdev = {
 559         .minor =        WATCHDOG_MINOR,
 560         .name =         "watchdog",
 561         .fops =         &usb_pcwd_fops,
 562 };
 563
 564 static const struct file_operations usb_pcwd_temperature_fops = {
 565         .owner =        THIS_MODULE,
 566         .llseek =       no_llseek,
 567         .read =         usb_pcwd_temperature_read,
 568         .open =         usb_pcwd_temperature_open,
 569         .release =      usb_pcwd_temperature_release,
 570 };
 571
 572 static struct miscdevice usb_pcwd_temperature_miscdev = {
 573         .minor =        TEMP_MINOR,
 574         .name =         "temperature",
 575         .fops =         &usb_pcwd_temperature_fops,
 576 };
 577
 578 static struct notifier_block usb_pcwd_notifier = {
 579         .notifier_call =        usb_pcwd_notify_sys,
 580 };
 581
 582 /**
 583  *      usb_pcwd_delete
 584  */
 585 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 586 {
 587         usb_free_urb(usb_pcwd->intr_urb);
 588         usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 589                           usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 590         kfree(usb_pcwd);
 591 }
 592
 593 /**
 594  *      usb_pcwd_probe
 595  *
 596  *      Called by the usb core when a new device is connected that it thinks
 597  *      this driver might be interested in.
 598  */
 599 static int usb_pcwd_probe(struct usb_interface *interface,
 600                                                 const struct usb_device_id *id)
 601 {
 602         struct usb_device *udev = interface_to_usbdev(interface);
 603         struct usb_host_interface *iface_desc;
 604         struct usb_endpoint_descriptor *endpoint;
 605         struct usb_pcwd_private *usb_pcwd = NULL;
 606         int pipe;
 607         int retval = -ENOMEM;
 608         int got_fw_rev;
 609         unsigned char fw_rev_major, fw_rev_minor;
 610         char fw_ver_str[20];
 611         unsigned char option_switches, dummy;
 612
 613         cards_found++;
 614         if (cards_found > 1) {
 615                 pr_err("This driver only supports 1 device\n");
 616                 return -ENODEV;
 617         }
 618
 619         /* get the active interface descriptor */
 620         iface_desc = interface->cur_altsetting;
 621
 622         /* check out that we have a HID device */
 623         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 624                 pr_err("The device isn't a Human Interface Device\n");
 625                 return -ENODEV;
 626         }
 627
 628         if (iface_desc->desc.bNumEndpoints < 1)
 629                 return -ENODEV;
 630
 631         /* check out the endpoint: it has to be Interrupt & IN */
 632         endpoint = &iface_desc->endpoint[0].desc;
 633
 634         if (!usb_endpoint_is_int_in(endpoint)) {
 635                 /* we didn't find a Interrupt endpoint with direction IN */
 636                 pr_err("Couldn't find an INTR & IN endpoint\n");
 637                 return -ENODEV;
 638         }
 639
 640         /* get a handle to the interrupt data pipe */
 641         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 642
 643         /* allocate memory for our device and initialize it */
 644         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 645         if (usb_pcwd == NULL)
 646                 goto error;
 647
 648         usb_pcwd_device = usb_pcwd;
 649
 650         mutex_init(&usb_pcwd->mtx);
 651         usb_pcwd->udev = udev;
 652         usb_pcwd->interface = interface;
 653         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 654         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 655                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 656
 657         /* set up the memory buffer's */
 658         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 659                                         GFP_KERNEL, &usb_pcwd->intr_dma);
 660         if (!usb_pcwd->intr_buffer) {
 661                 pr_err("Out of memory\n");
 662                 goto error;
 663         }
 664
 665         /* allocate the urb's */
 666         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 667         if (!usb_pcwd->intr_urb)
 668                 goto error;
 669
 670         /* initialise the intr urb's */
 671         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 672                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 673                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 674         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 675         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 676
 677         /* register our interrupt URB with the USB system */
 678         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 679                 pr_err("Problem registering interrupt URB\n");
 680                 retval = -EIO; /* failure */
 681                 goto error;
 682         }
 683
 684         /* The device exists and can be communicated with */
 685         usb_pcwd->exists = 1;
 686
 687         /* disable card */
 688         usb_pcwd_stop(usb_pcwd);
 689
 690         /* Get the Firmware Version */
 691         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 692                                                 &fw_rev_major, &fw_rev_minor);
 693         if (got_fw_rev)
 694                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 695         else
 696                 sprintf(fw_ver_str, "<card no answer>");
 697
 698         pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
 699
 700         /* Get switch settings */
 701         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 702                                                         &option_switches);
 703
 704         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 705                 option_switches,
 706                 ((option_switches & 0x10) ? "ON" : "OFF"),
 707                 ((option_switches & 0x08) ? "ON" : "OFF"));
 708
 709         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 710         if (heartbeat == 0)
 711                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 712
 713         /* Check that the heartbeat value is within it's range ;
 714          * if not reset to the default */
 715         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 716                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 717                 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
 718                         WATCHDOG_HEARTBEAT);
 719         }
 720
 721         retval = register_reboot_notifier(&usb_pcwd_notifier);
 722         if (retval != 0) {
 723                 pr_err("cannot register reboot notifier (err=%d)\n", retval);
 724                 goto error;
 725         }
 726
 727         retval = misc_register(&usb_pcwd_temperature_miscdev);
 728         if (retval != 0) {
 729                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 730                        TEMP_MINOR, retval);
 731                 goto err_out_unregister_reboot;
 732         }
 733
 734         retval = misc_register(&usb_pcwd_miscdev);
 735         if (retval != 0) {
 736                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 737                        WATCHDOG_MINOR, retval);
 738                 goto err_out_misc_deregister;
 739         }
 740
 741         /* we can register the device now, as it is ready */
 742         usb_set_intfdata(interface, usb_pcwd);
 743
 744         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 745                 heartbeat, nowayout);
 746
 747         return 0;
 748
 749 err_out_misc_deregister:
 750         misc_deregister(&usb_pcwd_temperature_miscdev);
 751 err_out_unregister_reboot:
 752         unregister_reboot_notifier(&usb_pcwd_notifier);
 753 error:
 754         if (usb_pcwd)
 755                 usb_pcwd_delete(usb_pcwd);
 756         usb_pcwd_device = NULL;
 757         return retval;
 758 }
 759
 760
 761 /**
 762  *      usb_pcwd_disconnect
 763  *
 764  *      Called by the usb core when the device is removed from the system.
 765  *
 766  *      This routine guarantees that the driver will not submit any more urbs
 767  *      by clearing dev->udev.
 768  */
 769 static void usb_pcwd_disconnect(struct usb_interface *interface)
 770 {
 771         struct usb_pcwd_private *usb_pcwd;
 772
 773         /* prevent races with open() */
 774         mutex_lock(&disconnect_mutex);
 775
 776         usb_pcwd = usb_get_intfdata(interface);
 777         usb_set_intfdata(interface, NULL);
 778
 779         mutex_lock(&usb_pcwd->mtx);
 780
 781         /* Stop the timer before we leave */
 782         if (!nowayout)
 783                 usb_pcwd_stop(usb_pcwd);
 784
 785         /* We should now stop communicating with the USB PCWD device */
 786         usb_pcwd->exists = 0;
 787
 788         /* Deregister */
 789         misc_deregister(&usb_pcwd_miscdev);
 790         misc_deregister(&usb_pcwd_temperature_miscdev);
 791         unregister_reboot_notifier(&usb_pcwd_notifier);
 792
 793         mutex_unlock(&usb_pcwd->mtx);
 794
 795         /* Delete the USB PCWD device */
 796         usb_pcwd_delete(usb_pcwd);
 797
 798         cards_found--;
 799
 800         mutex_unlock(&disconnect_mutex);
 801
 802         pr_info("USB PC Watchdog disconnected\n");
 803 }
 804
 805 module_usb_driver(usb_pcwd_driver);