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