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