drivers/char/wdt_pci.c

   1 /*
   2  *      Industrial Computer Source WDT500/501 driver for Linux 2.1.x
   3  *
   4  *      (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
   5  *                              http://www.redhat.com
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  *
  12  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
  13  *      warranty for any of this software. This material is provided
  14  *      "AS-IS" and at no charge.
  15  *
  16  *      (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
  17  *
  18  *      Release 0.08.
  19  *
  20  *      Fixes
  21  *              Dave Gregorich  :       Modularisation and minor bugs
  22  *              Alan Cox        :       Added the watchdog ioctl() stuff
  23  *              Alan Cox        :       Fixed the reboot problem (as noted by
  24  *                                      Matt Crocker).
  25  *              Alan Cox        :       Added wdt= boot option
  26  *              Alan Cox        :       Cleaned up copy/user stuff
  27  *              Tim Hockin      :       Added insmod parameters, comment cleanup
  28  *                                      Parameterized timeout
  29  *              JP Nollmann     :       Added support for PCI wdt501p
  30  *              Alan Cox        :       Split ISA and PCI cards into two drivers
  31  *              Jeff Garzik     :       PCI cleanups
  32  */
  33
  34 #include <linux/config.h>
  35 #include <linux/module.h>
  36 #include <linux/version.h>
  37 #include <linux/types.h>
  38 #include <linux/errno.h>
  39 #include <linux/kernel.h>
  40 #include <linux/sched.h>
  41 #include <linux/miscdevice.h>
  42 #include <linux/watchdog.h>
  43 #define WDT_IS_PCI
  44 #include "wd501p.h"
  45 #include <linux/malloc.h>
  46 #include <linux/ioport.h>
  47 #include <linux/fcntl.h>
  48 #include <asm/io.h>
  49 #include <asm/uaccess.h>
  50 #include <asm/system.h>
  51 #include <linux/notifier.h>
  52 #include <linux/reboot.h>
  53 #include <linux/init.h>
  54
  55 #include <linux/pci.h>
  56
  57 #define PFX "wdt_pci: "
  58
  59 /*
  60  * Until Access I/O gets their application for a PCI vendor ID approved,
  61  * I don't think that it's appropriate to move these constants into the
  62  * regular pci_ids.h file. -- JPN 2000/01/18
  63  */
  64
  65 #ifndef PCI_VENDOR_ID_ACCESSIO
  66 #define PCI_VENDOR_ID_ACCESSIO 0x494f
  67 #endif
  68 #ifndef PCI_DEVICE_ID_WDG_CSM
  69 #define PCI_DEVICE_ID_WDG_CSM 0x22c0
  70 #endif
  71
  72 static int wdt_is_open=0;
  73
  74 /*
  75  *      You must set these - there is no sane way to probe for this board.
  76  *      You can use wdt=x,y to set these now.
  77  */
  78
  79 static int io=0x240;
  80 static int irq=11;
  81
  82 #define WD_TIMO (100*60)                /* 1 minute */
  83
  84 #ifndef MODULE
  85
  86 /**
  87  *      wdtpci_setup:
  88  *      @str: command line string
  89  *
  90  *      Setup options. The board isn't really probe-able so we have to
  91  *      get the user to tell us the configuration. Sane people build it
  92  *      modular but the others come here.
  93  */
  94
  95 static int __init wdtpci_setup(char *str)
  96 {
  97         int ints[4];
  98
  99         str = get_options (str, ARRAY_SIZE(ints), ints);
 100
 101         if (ints[0] > 0)
 102         {
 103                 io = ints[1];
 104                 if(ints[0] > 1)
 105                         irq = ints[2];
 106         }
 107
 108         return 1;
 109 }
 110
 111 __setup("wdt=", wdtpci_setup);
 112
 113 #endif /* !MODULE */
 114
 115 /*
 116  *      Programming support
 117  */
 118
 119 static void wdtpci_ctr_mode(int ctr, int mode)
 120 {
 121         ctr<<=6;
 122         ctr|=0x30;
 123         ctr|=(mode<<1);
 124         outb_p(ctr, WDT_CR);
 125 }
 126
 127 static void wdtpci_ctr_load(int ctr, int val)
 128 {
 129         outb_p(val&0xFF, WDT_COUNT0+ctr);
 130         outb_p(val>>8, WDT_COUNT0+ctr);
 131 }
 132
 133 /*
 134  *      Kernel methods.
 135  */
 136
 137
 138 /**
 139  *      wdtpci_status:
 140  *
 141  *      Extract the status information from a WDT watchdog device. There are
 142  *      several board variants so we have to know which bits are valid. Some
 143  *      bits default to one and some to zero in order to be maximally painful.
 144  *
 145  *      we then map the bits onto the status ioctl flags.
 146  */
 147
 148 static int wdtpci_status(void)
 149 {
 150         /*
 151          *      Status register to bit flags
 152          */
 153
 154         int flag=0;
 155         unsigned char status=inb_p(WDT_SR);
 156         status|=FEATUREMAP1;
 157         status&=~FEATUREMAP2;
 158
 159         if(!(status&WDC_SR_TGOOD))
 160                 flag|=WDIOF_OVERHEAT;
 161         if(!(status&WDC_SR_PSUOVER))
 162                 flag|=WDIOF_POWEROVER;
 163         if(!(status&WDC_SR_PSUUNDR))
 164                 flag|=WDIOF_POWERUNDER;
 165         if(!(status&WDC_SR_FANGOOD))
 166                 flag|=WDIOF_FANFAULT;
 167         if(status&WDC_SR_ISOI0)
 168                 flag|=WDIOF_EXTERN1;
 169         if(status&WDC_SR_ISII1)
 170                 flag|=WDIOF_EXTERN2;
 171         return flag;
 172 }
 173
 174 /**
 175  *      wdtpci_interrupt:
 176  *      @irq:           Interrupt number
 177  *      @dev_id:        Unused as we don't allow multiple devices.
 178  *      @regs:          Unused.
 179  *
 180  *      Handle an interrupt from the board. These are raised when the status
 181  *      map changes in what the board considers an interesting way. That means
 182  *      a failure condition occuring.
 183  */
 184
 185 static void wdtpci_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 186 {
 187         /*
 188          *      Read the status register see what is up and
 189          *      then printk it.
 190          */
 191
 192         unsigned char status=inb_p(WDT_SR);
 193
 194         status|=FEATUREMAP1;
 195         status&=~FEATUREMAP2;
 196
 197         printk(KERN_CRIT "WDT status %d\n", status);
 198
 199         if(!(status&WDC_SR_TGOOD))
 200                 printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
 201         if(!(status&WDC_SR_PSUOVER))
 202                 printk(KERN_CRIT "PSU over voltage.\n");
 203         if(!(status&WDC_SR_PSUUNDR))
 204                 printk(KERN_CRIT "PSU under voltage.\n");
 205         if(!(status&WDC_SR_FANGOOD))
 206                 printk(KERN_CRIT "Possible fan fault.\n");
 207         if(!(status&WDC_SR_WCCR))
 208 #ifdef SOFTWARE_REBOOT
 209 #ifdef ONLY_TESTING
 210                 printk(KERN_CRIT "Would Reboot.\n");
 211 #else
 212                 printk(KERN_CRIT "Initiating system reboot.\n");
 213                 machine_restart(NULL);
 214 #endif
 215 #else
 216                 printk(KERN_CRIT "Reset in 5ms.\n");
 217 #endif
 218 }
 219
 220
 221 static long long wdtpci_llseek(struct file *file, long long offset, int origin)
 222 {
 223         return -ESPIPE;
 224 }
 225
 226 /**
 227  *      wdtpci_ping:
 228  *
 229  *      Reload counter one with the watchdog timeout. We don't bother reloading
 230  *      the cascade counter.
 231  */
 232
 233 static void wdtpci_ping(void)
 234 {
 235         /* Write a watchdog value */
 236         inb_p(WDT_DC);
 237         wdtpci_ctr_mode(1,2);
 238         wdtpci_ctr_load(1,WD_TIMO);             /* Timeout */
 239         outb_p(0, WDT_DC);
 240 }
 241
 242 /**
 243  *      wdtpci_write:
 244  *      @file: file handle to the watchdog
 245  *      @buf: buffer to write (unused as data does not matter here
 246  *      @count: count of bytes
 247  *      @ppos: pointer to the position to write. No seeks allowed
 248  *
 249  *      A write to a watchdog device is defined as a keepalive signal. Any
 250  *      write of data will do, as we we don't define content meaning.
 251  */
 252
 253 static ssize_t wdtpci_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
 254 {
 255         /*  Can't seek (pwrite) on this device  */
 256         if (ppos != &file->f_pos)
 257                 return -ESPIPE;
 258
 259         if(count)
 260         {
 261                 wdtpci_ping();
 262                 return 1;
 263         }
 264         return 0;
 265 }
 266
 267 /**
 268  *      wdtpci_read:
 269  *      @file: file handle to the watchdog board
 270  *      @buf: buffer to write 1 byte into
 271  *      @count: length of buffer
 272  *      @ptr: offset (no seek allowed)
 273  *
 274  *      Read reports the temperature in degrees Fahrenheit. The API is in
 275  *      farenheit. It was designed by an imperial measurement luddite.
 276  */
 277
 278 static ssize_t wdtpci_read(struct file *file, char *buf, size_t count, loff_t *ptr)
 279 {
 280         unsigned short c=inb_p(WDT_RT);
 281         unsigned char cp;
 282
 283         /*  Can't seek (pread) on this device  */
 284         if (ptr != &file->f_pos)
 285                 return -ESPIPE;
 286
 287         switch(MINOR(file->f_dentry->d_inode->i_rdev))
 288         {
 289                 case TEMP_MINOR:
 290                         c*=11;
 291                         c/=15;
 292                         cp=c+7;
 293                         if(copy_to_user(buf,&cp,1))
 294                                 return -EFAULT;
 295                         return 1;
 296                 default:
 297                         return -EINVAL;
 298         }
 299 }
 300
 301 /**
 302  *      wdtpci_ioctl:
 303  *      @inode: inode of the device
 304  *      @file: file handle to the device
 305  *      @cmd: watchdog command
 306  *      @arg: argument pointer
 307  *
 308  *      The watchdog API defines a common set of functions for all watchdogs
 309  *      according to their available features. We only actually usefully support
 310  *      querying capabilities and current status.
 311  */
 312
 313 static int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 314         unsigned long arg)
 315 {
 316         static struct watchdog_info ident=
 317         {
 318                 WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER
 319                         |WDIOF_EXTERN1|WDIOF_EXTERN2|WDIOF_FANFAULT,
 320                 1,
 321                 "WDT500/501PCI"
 322         };
 323
 324         ident.options&=WDT_OPTION_MASK; /* Mask down to the card we have */
 325         switch(cmd)
 326         {
 327                 default:
 328                         return -ENOIOCTLCMD;
 329                 case WDIOC_GETSUPPORT:
 330                         return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))?-EFAULT:0;
 331
 332                 case WDIOC_GETSTATUS:
 333                         return put_user(wdtpci_status(),(int *)arg);
 334                 case WDIOC_GETBOOTSTATUS:
 335                         return put_user(0, (int *)arg);
 336                 case WDIOC_KEEPALIVE:
 337                         wdtpci_ping();
 338                         return 0;
 339         }
 340 }
 341
 342 /**
 343  *      wdtpci_open:
 344  *      @inode: inode of device
 345  *      @file: file handle to device
 346  *
 347  *      One of our two misc devices has been opened. The watchdog device is
 348  *      single open and on opening we load the counters. Counter zero is a
 349  *      100Hz cascade, into counter 1 which downcounts to reboot. When the
 350  *      counter triggers counter 2 downcounts the length of the reset pulse
 351  *      which set set to be as long as possible.
 352  */
 353
 354 static int wdtpci_open(struct inode *inode, struct file *file)
 355 {
 356         switch(MINOR(inode->i_rdev))
 357         {
 358                 case WATCHDOG_MINOR:
 359                         if(wdt_is_open)
 360                                 return -EBUSY;
 361                         MOD_INC_USE_COUNT;
 362                         /*
 363                          *      Activate
 364                          */
 365
 366                         wdt_is_open=1;
 367
 368                         inb_p(WDT_DC);          /* Disable */
 369
 370                         /*
 371                          * "pet" the watchdog, as Access says.
 372                          * This resets the clock outputs.
 373                          */
 374
 375                         wdtpci_ctr_mode(2,0);
 376                         outb_p(0, WDT_DC);
 377
 378                         inb_p(WDT_DC);
 379
 380                         outb_p(0, WDT_CLOCK);   /* 2.0833MHz clock */
 381                         inb_p(WDT_BUZZER);      /* disable */
 382                         inb_p(WDT_OPTONOTRST);  /* disable */
 383                         inb_p(WDT_OPTORST);     /* disable */
 384                         inb_p(WDT_PROGOUT);     /* disable */
 385                         wdtpci_ctr_mode(0,3);
 386                         wdtpci_ctr_mode(1,2);
 387                         wdtpci_ctr_mode(2,1);
 388                         wdtpci_ctr_load(0,20833);       /* count at 100Hz */
 389                         wdtpci_ctr_load(1,WD_TIMO);/* Timeout 60 seconds */
 390                         /* DO NOT LOAD CTR2 on PCI card! -- JPN */
 391                         outb_p(0, WDT_DC);      /* Enable */
 392                         return 0;
 393                 case TEMP_MINOR:
 394                         MOD_INC_USE_COUNT;
 395                         return 0;
 396                 default:
 397                         return -ENODEV;
 398         }
 399 }
 400
 401 /**
 402  *      wdtpci_close:
 403  *      @inode: inode to board
 404  *      @file: file handle to board
 405  *
 406  *      The watchdog has a configurable API. There is a religious dispute
 407  *      between people who want their watchdog to be able to shut down and
 408  *      those who want to be sure if the watchdog manager dies the machine
 409  *      reboots. In the former case we disable the counters, in the latter
 410  *      case you have to open it again very soon.
 411  */
 412
 413 static int wdtpci_release(struct inode *inode, struct file *file)
 414 {
 415         if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
 416         {
 417 #ifndef CONFIG_WATCHDOG_NOWAYOUT
 418                 inb_p(WDT_DC);          /* Disable counters */
 419                 wdtpci_ctr_load(2,0);   /* 0 length reset pulses now */
 420 #endif
 421                 wdt_is_open=0;
 422         }
 423         MOD_DEC_USE_COUNT;
 424         return 0;
 425 }
 426
 427 /**
 428  *      notify_sys:
 429  *      @this: our notifier block
 430  *      @code: the event being reported
 431  *      @unused: unused
 432  *
 433  *      Our notifier is called on system shutdowns. We want to turn the card
 434  *      off at reboot otherwise the machine will reboot again during memory
 435  *      test or worse yet during the following fsck. This would suck, in fact
 436  *      trust me - if it happens it does suck.
 437  */
 438
 439 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
 440         void *unused)
 441 {
 442         if(code==SYS_DOWN || code==SYS_HALT)
 443         {
 444                 /* Turn the card off */
 445                 inb_p(WDT_DC);
 446                 wdtpci_ctr_load(2,0);
 447         }
 448         return NOTIFY_DONE;
 449 }
 450
 451 /*
 452  *      Kernel Interfaces
 453  */
 454
 455
 456 static struct file_operations wdtpci_fops = {
 457         llseek:         wdtpci_llseek,
 458         read:           wdtpci_read,
 459         write:          wdtpci_write,
 460         ioctl:          wdtpci_ioctl,
 461         open:           wdtpci_open,
 462         release:        wdtpci_release,
 463 };
 464
 465 static struct miscdevice wdtpci_miscdev=
 466 {
 467         WATCHDOG_MINOR,
 468         "watchdog",
 469         &wdtpci_fops
 470 };
 471
 472 #ifdef CONFIG_WDT_501
 473 static struct miscdevice temp_miscdev=
 474 {
 475         TEMP_MINOR,
 476         "temperature",
 477         &wdtpci_fops
 478 };
 479 #endif
 480
 481 /*
 482  *      The WDT card needs to learn about soft shutdowns in order to
 483  *      turn the timebomb registers off.
 484  */
 485
 486 static struct notifier_block wdtpci_notifier=
 487 {
 488         wdtpci_notify_sys,
 489         NULL,
 490         0
 491 };
 492
 493
 494 static int __init wdtpci_init_one (struct pci_dev *dev,
 495                                    const struct pci_device_id *ent)
 496 {
 497         static int dev_count = 0;
 498
 499         dev_count++;
 500         if (dev_count > 1) {
 501                 printk (KERN_ERR PFX
 502                         "this driver only supports 1 device\n");
 503                 return -ENODEV;
 504         }
 505
 506         irq = dev->irq;
 507         io = pci_resource_start (dev, 2);
 508         printk ("WDT501-P(PCI-WDG-CSM) driver 0.07 at %X "
 509                 "(Interrupt %d)\n", io, irq);
 510
 511         if (pci_enable_device (dev))
 512                 goto err_out;
 513
 514         if (request_region (io, 16, "wdt-pci") == NULL) {
 515                 printk (KERN_ERR PFX "I/O %d is not free.\n", io);
 516                 goto err_out;
 517         }
 518
 519         if (request_irq (irq, wdtpci_interrupt, SA_INTERRUPT | SA_SHIRQ,
 520                          "wdt-pci", &wdtpci_miscdev)) {
 521                 printk (KERN_ERR PFX "IRQ %d is not free.\n", irq);
 522                 goto err_out_free_res;
 523         }
 524
 525         misc_register (&wdtpci_miscdev);
 526
 527 #ifdef CONFIG_WDT_501
 528         misc_register (&temp_miscdev);
 529 #endif
 530
 531         register_reboot_notifier (&wdtpci_notifier);
 532
 533         return 0;
 534
 535 err_out_free_res:
 536         release_region (io, 16);
 537 err_out:
 538         return -EIO;
 539 }
 540
 541
 542 static void __exit wdtpci_remove_one (struct pci_dev *pdev)
 543 {
 544         /* here we assume only one device will ever have
 545          * been picked up and registered by probe function */
 546         unregister_reboot_notifier(&wdtpci_notifier);
 547 #ifdef CONFIG_WDT_501_PCI
 548         misc_deregister(&temp_miscdev);
 549 #endif
 550         misc_deregister(&wdtpci_miscdev);
 551         free_irq(irq, &wdtpci_miscdev);
 552         release_region(io, 16);
 553 }
 554
 555
 556 static struct pci_device_id wdtpci_pci_tbl[] __initdata = {
 557         { PCI_VENDOR_ID_ACCESSIO, PCI_DEVICE_ID_WDG_CSM, PCI_ANY_ID, PCI_ANY_ID, },
 558         { 0, }, /* terminate list */
 559 };
 560 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
 561
 562
 563 static struct pci_driver wdtpci_driver = {
 564         name:           "wdt-pci",
 565         id_table:       wdtpci_pci_tbl,
 566         probe:          wdtpci_init_one,
 567         remove:         wdtpci_remove_one,
 568 };
 569
 570
 571 /**
 572  *      wdtpci_cleanup:
 573  *
 574  *      Unload the watchdog. You cannot do this with any file handles open.
 575  *      If your watchdog is set to continue ticking on close and you unload
 576  *      it, well it keeps ticking. We won't get the interrupt but the board
 577  *      will not touch PC memory so all is fine. You just have to load a new
 578  *      module in 60 seconds or reboot.
 579  */
 580
 581 static void __exit wdtpci_cleanup(void)
 582 {
 583         pci_unregister_driver (&wdtpci_driver);
 584 }
 585
 586
 587 /**
 588  *      wdtpci_init:
 589  *
 590  *      Set up the WDT watchdog board. All we have to do is grab the
 591  *      resources we require and bitch if anyone beat us to them.
 592  *      The open() function will actually kick the board off.
 593  */
 594
 595 static int __init wdtpci_init(void)
 596 {
 597         int rc = pci_register_driver (&wdtpci_driver);
 598
 599         if (rc < 1)
 600                 return -ENODEV;
 601
 602         return 0;
 603 }
 604
 605
 606 module_init(wdtpci_init);
 607 module_exit(wdtpci_cleanup);