linux/drivers/watchdog/pcwd_usb.c
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   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#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#include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  44
  45
  46#ifdef CONFIG_USB_DEBUG
  47        static int debug = 1;
  48#else
  49        static int debug;
  50#endif
  51
  52/* Use our own dbg macro */
  53#undef dbg
  54#define dbg(format, arg...) \
  55        do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
  56
  57/* Module and Version Information */
  58#define DRIVER_VERSION "1.02"
  59#define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
  60#define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
  61#define DRIVER_LICENSE "GPL"
  62#define DRIVER_NAME "pcwd_usb"
  63#define PFX DRIVER_NAME ": "
  64
  65MODULE_AUTHOR(DRIVER_AUTHOR);
  66MODULE_DESCRIPTION(DRIVER_DESC);
  67MODULE_LICENSE(DRIVER_LICENSE);
  68MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
  69MODULE_ALIAS_MISCDEV(TEMP_MINOR);
  70
  71/* Module Parameters */
  72module_param(debug, int, 0);
  73MODULE_PARM_DESC(debug, "Debug enabled or not");
  74
  75#define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
  76                                                delay-time from dip-switches */
  77static int heartbeat = WATCHDOG_HEARTBEAT;
  78module_param(heartbeat, int, 0);
  79MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
  80        "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
  81                                __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  82
  83static int nowayout = WATCHDOG_NOWAYOUT;
  84module_param(nowayout, int, 0);
  85MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  86                                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  87
  88/* The vendor and product id's for the USB-PC Watchdog card */
  89#define USB_PCWD_VENDOR_ID      0x0c98
  90#define USB_PCWD_PRODUCT_ID     0x1140
  91
  92/* table of devices that work with this driver */
  93static struct usb_device_id usb_pcwd_table[] = {
  94        { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
  95        { }                                     /* Terminating entry */
  96};
  97MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
  98
  99/* according to documentation max. time to process a command for the USB
 100 * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
 101#define USB_COMMAND_TIMEOUT     250
 102
 103/* Watchdog's internal commands */
 104#define CMD_READ_TEMP                   0x02    /* Read Temperature;
 105                                                        Re-trigger Watchdog */
 106#define CMD_TRIGGER                     CMD_READ_TEMP
 107#define CMD_GET_STATUS                  0x04    /* Get Status Information */
 108#define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
 109#define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
 110#define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
 111#define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
 112#define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
 113#define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
 114
 115/* Watchdog's Dip Switch heartbeat values */
 116static const int heartbeat_tbl[] = {
 117        5,      /* OFF-OFF-OFF  =  5 Sec  */
 118        10,     /* OFF-OFF-ON   = 10 Sec  */
 119        30,     /* OFF-ON-OFF   = 30 Sec  */
 120        60,     /* OFF-ON-ON    =  1 Min  */
 121        300,    /* ON-OFF-OFF   =  5 Min  */
 122        600,    /* ON-OFF-ON    = 10 Min  */
 123        1800,   /* ON-ON-OFF    = 30 Min  */
 124        3600,   /* ON-ON-ON     =  1 hour */
 125};
 126
 127/* We can only use 1 card due to the /dev/watchdog restriction */
 128static int cards_found;
 129
 130/* some internal variables */
 131static unsigned long is_active;
 132static char expect_release;
 133
 134/* Structure to hold all of our device specific stuff */
 135struct usb_pcwd_private {
 136        /* save off the usb device pointer */
 137        struct usb_device       *udev;
 138        /* the interface for this device */
 139        struct usb_interface    *interface;
 140
 141        /* the interface number used for cmd's */
 142        unsigned int            interface_number;
 143
 144        /* the buffer to intr data */
 145        unsigned char           *intr_buffer;
 146        /* the dma address for the intr buffer */
 147        dma_addr_t              intr_dma;
 148        /* the size of the intr buffer */
 149        size_t                  intr_size;
 150        /* the urb used for the intr pipe */
 151        struct urb              *intr_urb;
 152
 153        /* The command that is reported back */
 154        unsigned char           cmd_command;
 155        /* The data MSB that is reported back */
 156        unsigned char           cmd_data_msb;
 157        /* The data LSB that is reported back */
 158        unsigned char           cmd_data_lsb;
 159        /* true if we received a report after a command */
 160        atomic_t                cmd_received;
 161
 162        /* Wether or not the device exists */
 163        int                     exists;
 164        /* locks this structure */
 165        struct mutex            mtx;
 166};
 167static struct usb_pcwd_private *usb_pcwd_device;
 168
 169/* prevent races between open() and disconnect() */
 170static DEFINE_MUTEX(disconnect_mutex);
 171
 172/* local function prototypes */
 173static int usb_pcwd_probe(struct usb_interface *interface,
 174                                                const struct usb_device_id *id);
 175static void usb_pcwd_disconnect(struct usb_interface *interface);
 176
 177/* usb specific object needed to register this driver with the usb subsystem */
 178static struct usb_driver usb_pcwd_driver = {
 179        .name =         DRIVER_NAME,
 180        .probe =        usb_pcwd_probe,
 181        .disconnect =   usb_pcwd_disconnect,
 182        .id_table =     usb_pcwd_table,
 183};
 184
 185
 186static void usb_pcwd_intr_done(struct urb *urb)
 187{
 188        struct usb_pcwd_private *usb_pcwd =
 189                                (struct usb_pcwd_private *)urb->context;
 190        unsigned char *data = usb_pcwd->intr_buffer;
 191        int retval;
 192
 193        switch (urb->status) {
 194        case 0:                 /* success */
 195                break;
 196        case -ECONNRESET:       /* unlink */
 197        case -ENOENT:
 198        case -ESHUTDOWN:
 199                /* this urb is terminated, clean up */
 200                dbg("%s - urb shutting down with status: %d", __func__,
 201                                                                urb->status);
 202                return;
 203        /* -EPIPE:  should clear the halt */
 204        default:                /* error */
 205                dbg("%s - nonzero urb status received: %d", __func__,
 206                                                                urb->status);
 207                goto resubmit;
 208        }
 209
 210        dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 211                data[0], data[1], data[2]);
 212
 213        usb_pcwd->cmd_command  = data[0];
 214        usb_pcwd->cmd_data_msb = data[1];
 215        usb_pcwd->cmd_data_lsb = data[2];
 216
 217        /* notify anyone waiting that the cmd has finished */
 218        atomic_set(&usb_pcwd->cmd_received, 1);
 219
 220resubmit:
 221        retval = usb_submit_urb(urb, GFP_ATOMIC);
 222        if (retval)
 223                printk(KERN_ERR PFX "can't resubmit intr, "
 224                        "usb_submit_urb failed with result %d\n", retval);
 225}
 226
 227static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 228                unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 229{
 230        int got_response, count;
 231        unsigned char buf[6];
 232
 233        /* We will not send any commands if the USB PCWD device does
 234         * not exist */
 235        if ((!usb_pcwd) || (!usb_pcwd->exists))
 236                return -1;
 237
 238        /* The USB PC Watchdog uses a 6 byte report format.
 239         * The board currently uses only 3 of the six bytes of the report. */
 240        buf[0] = cmd;                   /* Byte 0 = CMD */
 241        buf[1] = *msb;                  /* Byte 1 = Data MSB */
 242        buf[2] = *lsb;                  /* Byte 2 = Data LSB */
 243        buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
 244
 245        dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
 246                buf[0], buf[1], buf[2]);
 247
 248        atomic_set(&usb_pcwd->cmd_received, 0);
 249
 250        if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
 251                        HID_REQ_SET_REPORT, HID_DT_REPORT,
 252                        0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
 253                        USB_COMMAND_TIMEOUT) != sizeof(buf)) {
 254                dbg("usb_pcwd_send_command: error in usb_control_msg for "
 255                                "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
 256        }
 257        /* wait till the usb card processed the command,
 258         * with a max. timeout of USB_COMMAND_TIMEOUT */
 259        got_response = 0;
 260        for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
 261                                                                count++) {
 262                mdelay(1);
 263                if (atomic_read(&usb_pcwd->cmd_received))
 264                        got_response = 1;
 265        }
 266
 267        if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
 268                /* read back response */
 269                *msb = usb_pcwd->cmd_data_msb;
 270                *lsb = usb_pcwd->cmd_data_lsb;
 271        }
 272
 273        return got_response;
 274}
 275
 276static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
 277{
 278        unsigned char msb = 0x00;
 279        unsigned char lsb = 0x00;
 280        int retval;
 281
 282        /* Enable Watchdog */
 283        retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
 284                                                                &msb, &lsb);
 285
 286        if ((retval == 0) || (lsb == 0)) {
 287                printk(KERN_ERR PFX
 288                                "Card did not acknowledge enable attempt\n");
 289                return -1;
 290        }
 291
 292        return 0;
 293}
 294
 295static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
 296{
 297        unsigned char msb = 0xA5;
 298        unsigned char lsb = 0xC3;
 299        int retval;
 300
 301        /* Disable Watchdog */
 302        retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
 303                                                                &msb, &lsb);
 304
 305        if ((retval == 0) || (lsb != 0)) {
 306                printk(KERN_ERR PFX
 307                        "Card did not acknowledge disable attempt\n");
 308                return -1;
 309        }
 310
 311        return 0;
 312}
 313
 314static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
 315{
 316        unsigned char dummy;
 317
 318        /* Re-trigger Watchdog */
 319        usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
 320
 321        return 0;
 322}
 323
 324static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
 325{
 326        unsigned char msb = t / 256;
 327        unsigned char lsb = t % 256;
 328
 329        if ((t < 0x0001) || (t > 0xFFFF))
 330                return -EINVAL;
 331
 332        /* Write new heartbeat to watchdog */
 333        usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
 334
 335        heartbeat = t;
 336        return 0;
 337}
 338
 339static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
 340                                                        int *temperature)
 341{
 342        unsigned char msb, lsb;
 343
 344        usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
 345
 346        /*
 347         * Convert celsius to fahrenheit, since this was
 348         * the decided 'standard' for this return value.
 349         */
 350        *temperature = (lsb * 9 / 5) + 32;
 351
 352        return 0;
 353}
 354
 355static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
 356                                                                int *time_left)
 357{
 358        unsigned char msb, lsb;
 359
 360        /* Read the time that's left before rebooting */
 361        /* Note: if the board is not yet armed then we will read 0xFFFF */
 362        usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
 363
 364        *time_left = (msb << 8) + lsb;
 365
 366        return 0;
 367}
 368
 369/*
 370 *      /dev/watchdog handling
 371 */
 372
 373static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
 374                                                size_t len, loff_t *ppos)
 375{
 376        /* See if we got the magic character 'V' and reload the timer */
 377        if (len) {
 378                if (!nowayout) {
 379                        size_t i;
 380
 381                        /* note: just in case someone wrote the magic character
 382                         * five months ago... */
 383                        expect_release = 0;
 384
 385                        /* scan to see whether or not we got the
 386                         * magic character */
 387                        for (i = 0; i != len; i++) {
 388                                char c;
 389                                if (get_user(c, data + i))
 390                                        return -EFAULT;
 391                                if (c == 'V')
 392                                        expect_release = 42;
 393                        }
 394                }
 395
 396                /* someone wrote to us, we should reload the timer */
 397                usb_pcwd_keepalive(usb_pcwd_device);
 398        }
 399        return len;
 400}
 401
 402static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 403                                                unsigned long arg)
 404{
 405        void __user *argp = (void __user *)arg;
 406        int __user *p = argp;
 407        static const struct watchdog_info ident = {
 408                .options =              WDIOF_KEEPALIVEPING |
 409                                        WDIOF_SETTIMEOUT |
 410                                        WDIOF_MAGICCLOSE,
 411                .firmware_version =     1,
 412                .identity =             DRIVER_NAME,
 413        };
 414
 415        switch (cmd) {
 416        case WDIOC_GETSUPPORT:
 417                return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 418
 419        case WDIOC_GETSTATUS:
 420        case WDIOC_GETBOOTSTATUS:
 421                return put_user(0, p);
 422
 423        case WDIOC_GETTEMP:
 424        {
 425                int temperature;
 426
 427                if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 428                        return -EFAULT;
 429
 430                return put_user(temperature, p);
 431        }
 432
 433        case WDIOC_SETOPTIONS:
 434        {
 435                int new_options, retval = -EINVAL;
 436
 437                if (get_user(new_options, p))
 438                        return -EFAULT;
 439
 440                if (new_options & WDIOS_DISABLECARD) {
 441                        usb_pcwd_stop(usb_pcwd_device);
 442                        retval = 0;
 443                }
 444
 445                if (new_options & WDIOS_ENABLECARD) {
 446                        usb_pcwd_start(usb_pcwd_device);
 447                        retval = 0;
 448                }
 449
 450                return retval;
 451        }
 452
 453        case WDIOC_KEEPALIVE:
 454                usb_pcwd_keepalive(usb_pcwd_device);
 455                return 0;
 456
 457        case WDIOC_SETTIMEOUT:
 458        {
 459                int new_heartbeat;
 460
 461                if (get_user(new_heartbeat, p))
 462                        return -EFAULT;
 463
 464                if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
 465                        return -EINVAL;
 466
 467                usb_pcwd_keepalive(usb_pcwd_device);
 468                /* Fall */
 469        }
 470
 471        case WDIOC_GETTIMEOUT:
 472                return put_user(heartbeat, p);
 473
 474        case WDIOC_GETTIMELEFT:
 475        {
 476                int time_left;
 477
 478                if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
 479                        return -EFAULT;
 480
 481                return put_user(time_left, p);
 482        }
 483
 484        default:
 485                return -ENOTTY;
 486        }
 487}
 488
 489static int usb_pcwd_open(struct inode *inode, struct file *file)
 490{
 491        /* /dev/watchdog can only be opened once */
 492        if (test_and_set_bit(0, &is_active))
 493                return -EBUSY;
 494
 495        /* Activate */
 496        usb_pcwd_start(usb_pcwd_device);
 497        usb_pcwd_keepalive(usb_pcwd_device);
 498        return nonseekable_open(inode, file);
 499}
 500
 501static int usb_pcwd_release(struct inode *inode, struct file *file)
 502{
 503        /*
 504         *      Shut off the timer.
 505         */
 506        if (expect_release == 42) {
 507                usb_pcwd_stop(usb_pcwd_device);
 508        } else {
 509                printk(KERN_CRIT PFX
 510                        "Unexpected close, not stopping watchdog!\n");
 511                usb_pcwd_keepalive(usb_pcwd_device);
 512        }
 513        expect_release = 0;
 514        clear_bit(0, &is_active);
 515        return 0;
 516}
 517
 518/*
 519 *      /dev/temperature handling
 520 */
 521
 522static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
 523                                size_t len, loff_t *ppos)
 524{
 525        int temperature;
 526
 527        if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
 528                return -EFAULT;
 529
 530        if (copy_to_user(data, &temperature, 1))
 531                return -EFAULT;
 532
 533        return 1;
 534}
 535
 536static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
 537{
 538        return nonseekable_open(inode, file);
 539}
 540
 541static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
 542{
 543        return 0;
 544}
 545
 546/*
 547 *      Notify system
 548 */
 549
 550static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
 551                                                                void *unused)
 552{
 553        if (code == SYS_DOWN || code == SYS_HALT)
 554                usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
 555
 556        return NOTIFY_DONE;
 557}
 558
 559/*
 560 *      Kernel Interfaces
 561 */
 562
 563static const struct file_operations usb_pcwd_fops = {
 564        .owner =        THIS_MODULE,
 565        .llseek =       no_llseek,
 566        .write =        usb_pcwd_write,
 567        .unlocked_ioctl = usb_pcwd_ioctl,
 568        .open =         usb_pcwd_open,
 569        .release =      usb_pcwd_release,
 570};
 571
 572static struct miscdevice usb_pcwd_miscdev = {
 573        .minor =        WATCHDOG_MINOR,
 574        .name =         "watchdog",
 575        .fops =         &usb_pcwd_fops,
 576};
 577
 578static const struct file_operations usb_pcwd_temperature_fops = {
 579        .owner =        THIS_MODULE,
 580        .llseek =       no_llseek,
 581        .read =         usb_pcwd_temperature_read,
 582        .open =         usb_pcwd_temperature_open,
 583        .release =      usb_pcwd_temperature_release,
 584};
 585
 586static struct miscdevice usb_pcwd_temperature_miscdev = {
 587        .minor =        TEMP_MINOR,
 588        .name =         "temperature",
 589        .fops =         &usb_pcwd_temperature_fops,
 590};
 591
 592static struct notifier_block usb_pcwd_notifier = {
 593        .notifier_call =        usb_pcwd_notify_sys,
 594};
 595
 596/**
 597 *      usb_pcwd_delete
 598 */
 599static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 600{
 601        usb_free_urb(usb_pcwd->intr_urb);
 602        if (usb_pcwd->intr_buffer != NULL)
 603                usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
 604                                  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 605        kfree(usb_pcwd);
 606}
 607
 608/**
 609 *      usb_pcwd_probe
 610 *
 611 *      Called by the usb core when a new device is connected that it thinks
 612 *      this driver might be interested in.
 613 */
 614static int usb_pcwd_probe(struct usb_interface *interface,
 615                                                const struct usb_device_id *id)
 616{
 617        struct usb_device *udev = interface_to_usbdev(interface);
 618        struct usb_host_interface *iface_desc;
 619        struct usb_endpoint_descriptor *endpoint;
 620        struct usb_pcwd_private *usb_pcwd = NULL;
 621        int pipe, maxp;
 622        int retval = -ENOMEM;
 623        int got_fw_rev;
 624        unsigned char fw_rev_major, fw_rev_minor;
 625        char fw_ver_str[20];
 626        unsigned char option_switches, dummy;
 627
 628        cards_found++;
 629        if (cards_found > 1) {
 630                printk(KERN_ERR PFX "This driver only supports 1 device\n");
 631                return -ENODEV;
 632        }
 633
 634        /* get the active interface descriptor */
 635        iface_desc = interface->cur_altsetting;
 636
 637        /* check out that we have a HID device */
 638        if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
 639                printk(KERN_ERR PFX
 640                        "The device isn't a Human Interface Device\n");
 641                return -ENODEV;
 642        }
 643
 644        /* check out the endpoint: it has to be Interrupt & IN */
 645        endpoint = &iface_desc->endpoint[0].desc;
 646
 647        if (!usb_endpoint_is_int_in(endpoint)) {
 648                /* we didn't find a Interrupt endpoint with direction IN */
 649                printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
 650                return -ENODEV;
 651        }
 652
 653        /* get a handle to the interrupt data pipe */
 654        pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 655        maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
 656
 657        /* allocate memory for our device and initialize it */
 658        usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
 659        if (usb_pcwd == NULL) {
 660                printk(KERN_ERR PFX "Out of memory\n");
 661                goto error;
 662        }
 663
 664        usb_pcwd_device = usb_pcwd;
 665
 666        mutex_init(&usb_pcwd->mtx);
 667        usb_pcwd->udev = udev;
 668        usb_pcwd->interface = interface;
 669        usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 670        usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
 671                                le16_to_cpu(endpoint->wMaxPacketSize) : 8);
 672
 673        /* set up the memory buffer's */
 674        usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
 675                                        GFP_ATOMIC, &usb_pcwd->intr_dma);
 676        if (!usb_pcwd->intr_buffer) {
 677                printk(KERN_ERR PFX "Out of memory\n");
 678                goto error;
 679        }
 680
 681        /* allocate the urb's */
 682        usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
 683        if (!usb_pcwd->intr_urb) {
 684                printk(KERN_ERR PFX "Out of memory\n");
 685                goto error;
 686        }
 687
 688        /* initialise the intr urb's */
 689        usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
 690                        usb_pcwd->intr_buffer, usb_pcwd->intr_size,
 691                        usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
 692        usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
 693        usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 694
 695        /* register our interrupt URB with the USB system */
 696        if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
 697                printk(KERN_ERR PFX "Problem registering interrupt URB\n");
 698                retval = -EIO; /* failure */
 699                goto error;
 700        }
 701
 702        /* The device exists and can be communicated with */
 703        usb_pcwd->exists = 1;
 704
 705        /* disable card */
 706        usb_pcwd_stop(usb_pcwd);
 707
 708        /* Get the Firmware Version */
 709        got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
 710                                                &fw_rev_major, &fw_rev_minor);
 711        if (got_fw_rev)
 712                sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
 713        else
 714                sprintf(fw_ver_str, "<card no answer>");
 715
 716        printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
 717                fw_ver_str);
 718
 719        /* Get switch settings */
 720        usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
 721                                                        &option_switches);
 722
 723        printk(KERN_INFO PFX "Option switches (0x%02x): "
 724                "Temperature Reset Enable=%s, Power On Delay=%s\n",
 725                option_switches,
 726                ((option_switches & 0x10) ? "ON" : "OFF"),
 727                ((option_switches & 0x08) ? "ON" : "OFF"));
 728
 729        /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 730        if (heartbeat == 0)
 731                heartbeat = heartbeat_tbl[(option_switches & 0x07)];
 732
 733        /* Check that the heartbeat value is within it's range ;
 734         * if not reset to the default */
 735        if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
 736                usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
 737                printk(KERN_INFO PFX
 738                        "heartbeat value must be 0<heartbeat<65536, using %d\n",
 739                        WATCHDOG_HEARTBEAT);
 740        }
 741
 742        retval = register_reboot_notifier(&usb_pcwd_notifier);
 743        if (retval != 0) {
 744                printk(KERN_ERR PFX
 745                        "cannot register reboot notifier (err=%d)\n",
 746                        retval);
 747                goto error;
 748        }
 749
 750        retval = misc_register(&usb_pcwd_temperature_miscdev);
 751        if (retval != 0) {
 752                printk(KERN_ERR PFX
 753                        "cannot register miscdev on minor=%d (err=%d)\n",
 754                        TEMP_MINOR, retval);
 755                goto err_out_unregister_reboot;
 756        }
 757
 758        retval = misc_register(&usb_pcwd_miscdev);
 759        if (retval != 0) {
 760                printk(KERN_ERR PFX
 761                        "cannot register miscdev on minor=%d (err=%d)\n",
 762                        WATCHDOG_MINOR, retval);
 763                goto err_out_misc_deregister;
 764        }
 765
 766        /* we can register the device now, as it is ready */
 767        usb_set_intfdata(interface, usb_pcwd);
 768
 769        printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 770                heartbeat, nowayout);
 771
 772        return 0;
 773
 774err_out_misc_deregister:
 775        misc_deregister(&usb_pcwd_temperature_miscdev);
 776err_out_unregister_reboot:
 777        unregister_reboot_notifier(&usb_pcwd_notifier);
 778error:
 779        if (usb_pcwd)
 780                usb_pcwd_delete(usb_pcwd);
 781        usb_pcwd_device = NULL;
 782        return retval;
 783}
 784
 785
 786/**
 787 *      usb_pcwd_disconnect
 788 *
 789 *      Called by the usb core when the device is removed from the system.
 790 *
 791 *      This routine guarantees that the driver will not submit any more urbs
 792 *      by clearing dev->udev.
 793 */
 794static void usb_pcwd_disconnect(struct usb_interface *interface)
 795{
 796        struct usb_pcwd_private *usb_pcwd;
 797
 798        /* prevent races with open() */
 799        mutex_lock(&disconnect_mutex);
 800
 801        usb_pcwd = usb_get_intfdata(interface);
 802        usb_set_intfdata(interface, NULL);
 803
 804        mutex_lock(&usb_pcwd->mtx);
 805
 806        /* Stop the timer before we leave */
 807        if (!nowayout)
 808                usb_pcwd_stop(usb_pcwd);
 809
 810        /* We should now stop communicating with the USB PCWD device */
 811        usb_pcwd->exists = 0;
 812
 813        /* Deregister */
 814        misc_deregister(&usb_pcwd_miscdev);
 815        misc_deregister(&usb_pcwd_temperature_miscdev);
 816        unregister_reboot_notifier(&usb_pcwd_notifier);
 817
 818        mutex_unlock(&usb_pcwd->mtx);
 819
 820        /* Delete the USB PCWD device */
 821        usb_pcwd_delete(usb_pcwd);
 822
 823        cards_found--;
 824
 825        mutex_unlock(&disconnect_mutex);
 826
 827        printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
 828}
 829
 830
 831
 832/**
 833 *      usb_pcwd_init
 834 */
 835static int __init usb_pcwd_init(void)
 836{
 837        int result;
 838
 839        /* register this driver with the USB subsystem */
 840        result = usb_register(&usb_pcwd_driver);
 841        if (result) {
 842                printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
 843                    result);
 844                return result;
 845        }
 846
 847        printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION "\n");
 848        return 0;
 849}
 850
 851
 852/**
 853 *      usb_pcwd_exit
 854 */
 855static void __exit usb_pcwd_exit(void)
 856{
 857        /* deregister this driver with the USB subsystem */
 858        usb_deregister(&usb_pcwd_driver);
 859}
 860
 861
 862module_init(usb_pcwd_init);
 863module_exit(usb_pcwd_exit);
 864