git.oblomov.eu Git - linux-2.6/blob - drivers/char/hpet.c

   1 /*
   2  * Intel & MS High Precision Event Timer Implementation.
   3  *
   4  * Copyright (C) 2003 Intel Corporation
   5  *      Venki Pallipadi
   6  * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
   7  *      Bob Picco <robert.picco@hp.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/interrupt.h>
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/miscdevice.h>
  19 #include <linux/major.h>
  20 #include <linux/ioport.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/init.h>
  23 #include <linux/poll.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/wait.h>
  28 #include <linux/bcd.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/bitops.h>
  31
  32 #include <asm/current.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/system.h>
  35 #include <asm/io.h>
  36 #include <asm/irq.h>
  37 #include <asm/div64.h>
  38
  39 #include <linux/acpi.h>
  40 #include <acpi/acpi_bus.h>
  41 #include <linux/hpet.h>
  42
  43 /*
  44  * The High Precision Event Timer driver.
  45  * This driver is closely modelled after the rtc.c driver.
  46  * http://www.intel.com/hardwaredesign/hpetspec.htm
  47  */
  48 #define HPET_USER_FREQ  (64)
  49 #define HPET_DRIFT      (500)
  50
  51 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  52
  53 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  54
  55 /* A lock for concurrent access by app and isr hpet activity. */
  56 static DEFINE_SPINLOCK(hpet_lock);
  57 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  58 static DEFINE_SPINLOCK(hpet_task_lock);
  59
  60 #define HPET_DEV_NAME   (7)
  61
  62 struct hpet_dev {
  63         struct hpets *hd_hpets;
  64         struct hpet __iomem *hd_hpet;
  65         struct hpet_timer __iomem *hd_timer;
  66         unsigned long hd_ireqfreq;
  67         unsigned long hd_irqdata;
  68         wait_queue_head_t hd_waitqueue;
  69         struct fasync_struct *hd_async_queue;
  70         struct hpet_task *hd_task;
  71         unsigned int hd_flags;
  72         unsigned int hd_irq;
  73         unsigned int hd_hdwirq;
  74         char hd_name[HPET_DEV_NAME];
  75 };
  76
  77 struct hpets {
  78         struct hpets *hp_next;
  79         struct hpet __iomem *hp_hpet;
  80         unsigned long hp_hpet_phys;
  81         struct time_interpolator *hp_interpolator;
  82         unsigned long long hp_tick_freq;
  83         unsigned long hp_delta;
  84         unsigned int hp_ntimer;
  85         unsigned int hp_which;
  86         struct hpet_dev hp_dev[1];
  87 };
  88
  89 static struct hpets *hpets;
  90
  91 #define HPET_OPEN               0x0001
  92 #define HPET_IE                 0x0002  /* interrupt enabled */
  93 #define HPET_PERIODIC           0x0004
  94 #define HPET_SHARED_IRQ         0x0008
  95
  96 #if BITS_PER_LONG == 64
  97 #define write_counter(V, MC)    writeq(V, MC)
  98 #define read_counter(MC)        readq(MC)
  99 #else
 100 #define write_counter(V, MC)    writel(V, MC)
 101 #define read_counter(MC)        readl(MC)
 102 #endif
 103
 104 #ifndef readq
 105 static inline unsigned long long readq(void __iomem *addr)
 106 {
 107         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 108 }
 109 #endif
 110
 111 #ifndef writeq
 112 static inline void writeq(unsigned long long v, void __iomem *addr)
 113 {
 114         writel(v & 0xffffffff, addr);
 115         writel(v >> 32, addr + 4);
 116 }
 117 #endif
 118
 119 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
 120 {
 121         struct hpet_dev *devp;
 122         unsigned long isr;
 123
 124         devp = data;
 125         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 126
 127         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 128             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 129                 return IRQ_NONE;
 130
 131         spin_lock(&hpet_lock);
 132         devp->hd_irqdata++;
 133
 134         /*
 135          * For non-periodic timers, increment the accumulator.
 136          * This has the effect of treating non-periodic like periodic.
 137          */
 138         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 139                 unsigned long m, t;
 140
 141                 t = devp->hd_ireqfreq;
 142                 m = read_counter(&devp->hd_hpet->hpet_mc);
 143                 write_counter(t + m + devp->hd_hpets->hp_delta,
 144                               &devp->hd_timer->hpet_compare);
 145         }
 146
 147         if (devp->hd_flags & HPET_SHARED_IRQ)
 148                 writel(isr, &devp->hd_hpet->hpet_isr);
 149         spin_unlock(&hpet_lock);
 150
 151         spin_lock(&hpet_task_lock);
 152         if (devp->hd_task)
 153                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 154         spin_unlock(&hpet_task_lock);
 155
 156         wake_up_interruptible(&devp->hd_waitqueue);
 157
 158         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 159
 160         return IRQ_HANDLED;
 161 }
 162
 163 static int hpet_open(struct inode *inode, struct file *file)
 164 {
 165         struct hpet_dev *devp;
 166         struct hpets *hpetp;
 167         int i;
 168
 169         if (file->f_mode & FMODE_WRITE)
 170                 return -EINVAL;
 171
 172         spin_lock_irq(&hpet_lock);
 173
 174         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 175                 for (i = 0; i < hpetp->hp_ntimer; i++)
 176                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 177                             || hpetp->hp_dev[i].hd_task)
 178                                 continue;
 179                         else {
 180                                 devp = &hpetp->hp_dev[i];
 181                                 break;
 182                         }
 183
 184         if (!devp) {
 185                 spin_unlock_irq(&hpet_lock);
 186                 return -EBUSY;
 187         }
 188
 189         file->private_data = devp;
 190         devp->hd_irqdata = 0;
 191         devp->hd_flags |= HPET_OPEN;
 192         spin_unlock_irq(&hpet_lock);
 193
 194         return 0;
 195 }
 196
 197 static ssize_t
 198 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 199 {
 200         DECLARE_WAITQUEUE(wait, current);
 201         unsigned long data;
 202         ssize_t retval;
 203         struct hpet_dev *devp;
 204
 205         devp = file->private_data;
 206         if (!devp->hd_ireqfreq)
 207                 return -EIO;
 208
 209         if (count < sizeof(unsigned long))
 210                 return -EINVAL;
 211
 212         add_wait_queue(&devp->hd_waitqueue, &wait);
 213
 214         for ( ; ; ) {
 215                 set_current_state(TASK_INTERRUPTIBLE);
 216
 217                 spin_lock_irq(&hpet_lock);
 218                 data = devp->hd_irqdata;
 219                 devp->hd_irqdata = 0;
 220                 spin_unlock_irq(&hpet_lock);
 221
 222                 if (data)
 223                         break;
 224                 else if (file->f_flags & O_NONBLOCK) {
 225                         retval = -EAGAIN;
 226                         goto out;
 227                 } else if (signal_pending(current)) {
 228                         retval = -ERESTARTSYS;
 229                         goto out;
 230                 }
 231                 schedule();
 232         }
 233
 234         retval = put_user(data, (unsigned long __user *)buf);
 235         if (!retval)
 236                 retval = sizeof(unsigned long);
 237 out:
 238         __set_current_state(TASK_RUNNING);
 239         remove_wait_queue(&devp->hd_waitqueue, &wait);
 240
 241         return retval;
 242 }
 243
 244 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 245 {
 246         unsigned long v;
 247         struct hpet_dev *devp;
 248
 249         devp = file->private_data;
 250
 251         if (!devp->hd_ireqfreq)
 252                 return 0;
 253
 254         poll_wait(file, &devp->hd_waitqueue, wait);
 255
 256         spin_lock_irq(&hpet_lock);
 257         v = devp->hd_irqdata;
 258         spin_unlock_irq(&hpet_lock);
 259
 260         if (v != 0)
 261                 return POLLIN | POLLRDNORM;
 262
 263         return 0;
 264 }
 265
 266 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 267 {
 268 #ifdef  CONFIG_HPET_MMAP
 269         struct hpet_dev *devp;
 270         unsigned long addr;
 271
 272         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 273                 return -EINVAL;
 274
 275         devp = file->private_data;
 276         addr = devp->hd_hpets->hp_hpet_phys;
 277
 278         if (addr & (PAGE_SIZE - 1))
 279                 return -ENOSYS;
 280
 281         vma->vm_flags |= VM_IO;
 282         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 283
 284         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 285                                         PAGE_SIZE, vma->vm_page_prot)) {
 286                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
 287                         __FUNCTION__);
 288                 return -EAGAIN;
 289         }
 290
 291         return 0;
 292 #else
 293         return -ENOSYS;
 294 #endif
 295 }
 296
 297 static int hpet_fasync(int fd, struct file *file, int on)
 298 {
 299         struct hpet_dev *devp;
 300
 301         devp = file->private_data;
 302
 303         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 304                 return 0;
 305         else
 306                 return -EIO;
 307 }
 308
 309 static int hpet_release(struct inode *inode, struct file *file)
 310 {
 311         struct hpet_dev *devp;
 312         struct hpet_timer __iomem *timer;
 313         int irq = 0;
 314
 315         devp = file->private_data;
 316         timer = devp->hd_timer;
 317
 318         spin_lock_irq(&hpet_lock);
 319
 320         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 321                &timer->hpet_config);
 322
 323         irq = devp->hd_irq;
 324         devp->hd_irq = 0;
 325
 326         devp->hd_ireqfreq = 0;
 327
 328         if (devp->hd_flags & HPET_PERIODIC
 329             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 330                 unsigned long v;
 331
 332                 v = readq(&timer->hpet_config);
 333                 v ^= Tn_TYPE_CNF_MASK;
 334                 writeq(v, &timer->hpet_config);
 335         }
 336
 337         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 338         spin_unlock_irq(&hpet_lock);
 339
 340         if (irq)
 341                 free_irq(irq, devp);
 342
 343         if (file->f_flags & FASYNC)
 344                 hpet_fasync(-1, file, 0);
 345
 346         file->private_data = NULL;
 347         return 0;
 348 }
 349
 350 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 351
 352 static int
 353 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 354            unsigned long arg)
 355 {
 356         struct hpet_dev *devp;
 357
 358         devp = file->private_data;
 359         return hpet_ioctl_common(devp, cmd, arg, 0);
 360 }
 361
 362 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 363 {
 364         struct hpet_timer __iomem *timer;
 365         struct hpet __iomem *hpet;
 366         struct hpets *hpetp;
 367         int irq;
 368         unsigned long g, v, t, m;
 369         unsigned long flags, isr;
 370
 371         timer = devp->hd_timer;
 372         hpet = devp->hd_hpet;
 373         hpetp = devp->hd_hpets;
 374
 375         if (!devp->hd_ireqfreq)
 376                 return -EIO;
 377
 378         spin_lock_irq(&hpet_lock);
 379
 380         if (devp->hd_flags & HPET_IE) {
 381                 spin_unlock_irq(&hpet_lock);
 382                 return -EBUSY;
 383         }
 384
 385         devp->hd_flags |= HPET_IE;
 386
 387         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 388                 devp->hd_flags |= HPET_SHARED_IRQ;
 389         spin_unlock_irq(&hpet_lock);
 390
 391         irq = devp->hd_hdwirq;
 392
 393         if (irq) {
 394                 unsigned long irq_flags;
 395
 396                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 397                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 398                                                 ? IRQF_SHARED : IRQF_DISABLED;
 399                 if (request_irq(irq, hpet_interrupt, irq_flags,
 400                                 devp->hd_name, (void *)devp)) {
 401                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 402                         irq = 0;
 403                 }
 404         }
 405
 406         if (irq == 0) {
 407                 spin_lock_irq(&hpet_lock);
 408                 devp->hd_flags ^= HPET_IE;
 409                 spin_unlock_irq(&hpet_lock);
 410                 return -EIO;
 411         }
 412
 413         devp->hd_irq = irq;
 414         t = devp->hd_ireqfreq;
 415         v = readq(&timer->hpet_config);
 416         g = v | Tn_INT_ENB_CNF_MASK;
 417
 418         if (devp->hd_flags & HPET_PERIODIC) {
 419                 write_counter(t, &timer->hpet_compare);
 420                 g |= Tn_TYPE_CNF_MASK;
 421                 v |= Tn_TYPE_CNF_MASK;
 422                 writeq(v, &timer->hpet_config);
 423                 v |= Tn_VAL_SET_CNF_MASK;
 424                 writeq(v, &timer->hpet_config);
 425                 local_irq_save(flags);
 426                 m = read_counter(&hpet->hpet_mc);
 427                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 428         } else {
 429                 local_irq_save(flags);
 430                 m = read_counter(&hpet->hpet_mc);
 431                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 432         }
 433
 434         if (devp->hd_flags & HPET_SHARED_IRQ) {
 435                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 436                 writel(isr, &hpet->hpet_isr);
 437         }
 438         writeq(g, &timer->hpet_config);
 439         local_irq_restore(flags);
 440
 441         return 0;
 442 }
 443
 444 /* converts Hz to number of timer ticks */
 445 static inline unsigned long hpet_time_div(struct hpets *hpets,
 446                                           unsigned long dis)
 447 {
 448         unsigned long long m;
 449
 450         m = hpets->hp_tick_freq + (dis >> 1);
 451         do_div(m, dis);
 452         return (unsigned long)m;
 453 }
 454
 455 static int
 456 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 457 {
 458         struct hpet_timer __iomem *timer;
 459         struct hpet __iomem *hpet;
 460         struct hpets *hpetp;
 461         int err;
 462         unsigned long v;
 463
 464         switch (cmd) {
 465         case HPET_IE_OFF:
 466         case HPET_INFO:
 467         case HPET_EPI:
 468         case HPET_DPI:
 469         case HPET_IRQFREQ:
 470                 timer = devp->hd_timer;
 471                 hpet = devp->hd_hpet;
 472                 hpetp = devp->hd_hpets;
 473                 break;
 474         case HPET_IE_ON:
 475                 return hpet_ioctl_ieon(devp);
 476         default:
 477                 return -EINVAL;
 478         }
 479
 480         err = 0;
 481
 482         switch (cmd) {
 483         case HPET_IE_OFF:
 484                 if ((devp->hd_flags & HPET_IE) == 0)
 485                         break;
 486                 v = readq(&timer->hpet_config);
 487                 v &= ~Tn_INT_ENB_CNF_MASK;
 488                 writeq(v, &timer->hpet_config);
 489                 if (devp->hd_irq) {
 490                         free_irq(devp->hd_irq, devp);
 491                         devp->hd_irq = 0;
 492                 }
 493                 devp->hd_flags ^= HPET_IE;
 494                 break;
 495         case HPET_INFO:
 496                 {
 497                         struct hpet_info info;
 498
 499                         if (devp->hd_ireqfreq)
 500                                 info.hi_ireqfreq =
 501                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 502                         else
 503                                 info.hi_ireqfreq = 0;
 504                         info.hi_flags =
 505                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 506                         info.hi_hpet = hpetp->hp_which;
 507                         info.hi_timer = devp - hpetp->hp_dev;
 508                         if (kernel)
 509                                 memcpy((void *)arg, &info, sizeof(info));
 510                         else
 511                                 if (copy_to_user((void __user *)arg, &info,
 512                                                  sizeof(info)))
 513                                         err = -EFAULT;
 514                         break;
 515                 }
 516         case HPET_EPI:
 517                 v = readq(&timer->hpet_config);
 518                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 519                         err = -ENXIO;
 520                         break;
 521                 }
 522                 devp->hd_flags |= HPET_PERIODIC;
 523                 break;
 524         case HPET_DPI:
 525                 v = readq(&timer->hpet_config);
 526                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 527                         err = -ENXIO;
 528                         break;
 529                 }
 530                 if (devp->hd_flags & HPET_PERIODIC &&
 531                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 532                         v = readq(&timer->hpet_config);
 533                         v ^= Tn_TYPE_CNF_MASK;
 534                         writeq(v, &timer->hpet_config);
 535                 }
 536                 devp->hd_flags &= ~HPET_PERIODIC;
 537                 break;
 538         case HPET_IRQFREQ:
 539                 if (!kernel && (arg > hpet_max_freq) &&
 540                     !capable(CAP_SYS_RESOURCE)) {
 541                         err = -EACCES;
 542                         break;
 543                 }
 544
 545                 if (!arg) {
 546                         err = -EINVAL;
 547                         break;
 548                 }
 549
 550                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 551         }
 552
 553         return err;
 554 }
 555
 556 static const struct file_operations hpet_fops = {
 557         .owner = THIS_MODULE,
 558         .llseek = no_llseek,
 559         .read = hpet_read,
 560         .poll = hpet_poll,
 561         .ioctl = hpet_ioctl,
 562         .open = hpet_open,
 563         .release = hpet_release,
 564         .fasync = hpet_fasync,
 565         .mmap = hpet_mmap,
 566 };
 567
 568 static int hpet_is_known(struct hpet_data *hdp)
 569 {
 570         struct hpets *hpetp;
 571
 572         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 573                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 574                         return 1;
 575
 576         return 0;
 577 }
 578
 579 EXPORT_SYMBOL(hpet_alloc);
 580 EXPORT_SYMBOL(hpet_register);
 581 EXPORT_SYMBOL(hpet_unregister);
 582 EXPORT_SYMBOL(hpet_control);
 583
 584 int hpet_register(struct hpet_task *tp, int periodic)
 585 {
 586         unsigned int i;
 587         u64 mask;
 588         struct hpet_timer __iomem *timer;
 589         struct hpet_dev *devp;
 590         struct hpets *hpetp;
 591
 592         switch (periodic) {
 593         case 1:
 594                 mask = Tn_PER_INT_CAP_MASK;
 595                 break;
 596         case 0:
 597                 mask = 0;
 598                 break;
 599         default:
 600                 return -EINVAL;
 601         }
 602
 603         tp->ht_opaque = NULL;
 604
 605         spin_lock_irq(&hpet_task_lock);
 606         spin_lock(&hpet_lock);
 607
 608         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 609                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
 610                      i < hpetp->hp_ntimer; i++, timer++) {
 611                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
 612                             != mask)
 613                                 continue;
 614
 615                         devp = &hpetp->hp_dev[i];
 616
 617                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
 618                                 devp = NULL;
 619                                 continue;
 620                         }
 621
 622                         tp->ht_opaque = devp;
 623                         devp->hd_task = tp;
 624                         break;
 625                 }
 626
 627         spin_unlock(&hpet_lock);
 628         spin_unlock_irq(&hpet_task_lock);
 629
 630         if (tp->ht_opaque)
 631                 return 0;
 632         else
 633                 return -EBUSY;
 634 }
 635
 636 static inline int hpet_tpcheck(struct hpet_task *tp)
 637 {
 638         struct hpet_dev *devp;
 639         struct hpets *hpetp;
 640
 641         devp = tp->ht_opaque;
 642
 643         if (!devp)
 644                 return -ENXIO;
 645
 646         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 647                 if (devp >= hpetp->hp_dev
 648                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 649                     && devp->hd_hpet == hpetp->hp_hpet)
 650                         return 0;
 651
 652         return -ENXIO;
 653 }
 654
 655 int hpet_unregister(struct hpet_task *tp)
 656 {
 657         struct hpet_dev *devp;
 658         struct hpet_timer __iomem *timer;
 659         int err;
 660
 661         if ((err = hpet_tpcheck(tp)))
 662                 return err;
 663
 664         spin_lock_irq(&hpet_task_lock);
 665         spin_lock(&hpet_lock);
 666
 667         devp = tp->ht_opaque;
 668         if (devp->hd_task != tp) {
 669                 spin_unlock(&hpet_lock);
 670                 spin_unlock_irq(&hpet_task_lock);
 671                 return -ENXIO;
 672         }
 673
 674         timer = devp->hd_timer;
 675         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 676                &timer->hpet_config);
 677         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 678         devp->hd_task = NULL;
 679         spin_unlock(&hpet_lock);
 680         spin_unlock_irq(&hpet_task_lock);
 681
 682         return 0;
 683 }
 684
 685 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
 686 {
 687         struct hpet_dev *devp;
 688         int err;
 689
 690         if ((err = hpet_tpcheck(tp)))
 691                 return err;
 692
 693         spin_lock_irq(&hpet_lock);
 694         devp = tp->ht_opaque;
 695         if (devp->hd_task != tp) {
 696                 spin_unlock_irq(&hpet_lock);
 697                 return -ENXIO;
 698         }
 699         spin_unlock_irq(&hpet_lock);
 700         return hpet_ioctl_common(devp, cmd, arg, 1);
 701 }
 702
 703 static ctl_table hpet_table[] = {
 704         {
 705          .ctl_name = 1,
 706          .procname = "max-user-freq",
 707          .data = &hpet_max_freq,
 708          .maxlen = sizeof(int),
 709          .mode = 0644,
 710          .proc_handler = &proc_dointvec,
 711          },
 712         {.ctl_name = 0}
 713 };
 714
 715 static ctl_table hpet_root[] = {
 716         {
 717          .ctl_name = 1,
 718          .procname = "hpet",
 719          .maxlen = 0,
 720          .mode = 0555,
 721          .child = hpet_table,
 722          },
 723         {.ctl_name = 0}
 724 };
 725
 726 static ctl_table dev_root[] = {
 727         {
 728          .ctl_name = CTL_DEV,
 729          .procname = "dev",
 730          .maxlen = 0,
 731          .mode = 0555,
 732          .child = hpet_root,
 733          },
 734         {.ctl_name = 0}
 735 };
 736
 737 static struct ctl_table_header *sysctl_header;
 738
 739 static void hpet_register_interpolator(struct hpets *hpetp)
 740 {
 741 #ifdef  CONFIG_TIME_INTERPOLATION
 742         struct time_interpolator *ti;
 743
 744         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
 745         if (!ti)
 746                 return;
 747
 748         ti->source = TIME_SOURCE_MMIO64;
 749         ti->shift = 10;
 750         ti->addr = &hpetp->hp_hpet->hpet_mc;
 751         ti->frequency = hpetp->hp_tick_freq;
 752         ti->drift = HPET_DRIFT;
 753         ti->mask = -1;
 754
 755         hpetp->hp_interpolator = ti;
 756         register_time_interpolator(ti);
 757 #endif
 758 }
 759
 760 /*
 761  * Adjustment for when arming the timer with
 762  * initial conditions.  That is, main counter
 763  * ticks expired before interrupts are enabled.
 764  */
 765 #define TICK_CALIBRATE  (1000UL)
 766
 767 static unsigned long hpet_calibrate(struct hpets *hpetp)
 768 {
 769         struct hpet_timer __iomem *timer = NULL;
 770         unsigned long t, m, count, i, flags, start;
 771         struct hpet_dev *devp;
 772         int j;
 773         struct hpet __iomem *hpet;
 774
 775         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 776                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 777                         timer = devp->hd_timer;
 778                         break;
 779                 }
 780
 781         if (!timer)
 782                 return 0;
 783
 784         hpet = hpetp->hp_hpet;
 785         t = read_counter(&timer->hpet_compare);
 786
 787         i = 0;
 788         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 789
 790         local_irq_save(flags);
 791
 792         start = read_counter(&hpet->hpet_mc);
 793
 794         do {
 795                 m = read_counter(&hpet->hpet_mc);
 796                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 797         } while (i++, (m - start) < count);
 798
 799         local_irq_restore(flags);
 800
 801         return (m - start) / i;
 802 }
 803
 804 int hpet_alloc(struct hpet_data *hdp)
 805 {
 806         u64 cap, mcfg;
 807         struct hpet_dev *devp;
 808         u32 i, ntimer;
 809         struct hpets *hpetp;
 810         size_t siz;
 811         struct hpet __iomem *hpet;
 812         static struct hpets *last = NULL;
 813         unsigned long period;
 814         unsigned long long temp;
 815
 816         /*
 817          * hpet_alloc can be called by platform dependent code.
 818          * If platform dependent code has allocated the hpet that
 819          * ACPI has also reported, then we catch it here.
 820          */
 821         if (hpet_is_known(hdp)) {
 822                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 823                         __FUNCTION__);
 824                 return 0;
 825         }
 826
 827         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 828                                       sizeof(struct hpet_dev));
 829
 830         hpetp = kzalloc(siz, GFP_KERNEL);
 831
 832         if (!hpetp)
 833                 return -ENOMEM;
 834
 835         hpetp->hp_which = hpet_nhpet++;
 836         hpetp->hp_hpet = hdp->hd_address;
 837         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 838
 839         hpetp->hp_ntimer = hdp->hd_nirqs;
 840
 841         for (i = 0; i < hdp->hd_nirqs; i++)
 842                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 843
 844         hpet = hpetp->hp_hpet;
 845
 846         cap = readq(&hpet->hpet_cap);
 847
 848         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 849
 850         if (hpetp->hp_ntimer != ntimer) {
 851                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 852                        " with number of timers\n");
 853                 kfree(hpetp);
 854                 return -ENODEV;
 855         }
 856
 857         if (last)
 858                 last->hp_next = hpetp;
 859         else
 860                 hpets = hpetp;
 861
 862         last = hpetp;
 863
 864         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 865                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 866         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 867         temp += period >> 1; /* round */
 868         do_div(temp, period);
 869         hpetp->hp_tick_freq = temp; /* ticks per second */
 870
 871         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 872                 hpetp->hp_which, hdp->hd_phys_address,
 873                 hpetp->hp_ntimer > 1 ? "s" : "");
 874         for (i = 0; i < hpetp->hp_ntimer; i++)
 875                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 876         printk("\n");
 877
 878         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
 879                hpetp->hp_which, hpetp->hp_ntimer,
 880                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
 881
 882         mcfg = readq(&hpet->hpet_config);
 883         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 884                 write_counter(0L, &hpet->hpet_mc);
 885                 mcfg |= HPET_ENABLE_CNF_MASK;
 886                 writeq(mcfg, &hpet->hpet_config);
 887         }
 888
 889         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 890                 struct hpet_timer __iomem *timer;
 891
 892                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 893
 894                 devp->hd_hpets = hpetp;
 895                 devp->hd_hpet = hpet;
 896                 devp->hd_timer = timer;
 897
 898                 /*
 899                  * If the timer was reserved by platform code,
 900                  * then make timer unavailable for opens.
 901                  */
 902                 if (hdp->hd_state & (1 << i)) {
 903                         devp->hd_flags = HPET_OPEN;
 904                         continue;
 905                 }
 906
 907                 init_waitqueue_head(&devp->hd_waitqueue);
 908         }
 909
 910         hpetp->hp_delta = hpet_calibrate(hpetp);
 911         hpet_register_interpolator(hpetp);
 912
 913         return 0;
 914 }
 915
 916 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 917 {
 918         struct hpet_data *hdp;
 919         acpi_status status;
 920         struct acpi_resource_address64 addr;
 921
 922         hdp = data;
 923
 924         status = acpi_resource_to_address64(res, &addr);
 925
 926         if (ACPI_SUCCESS(status)) {
 927                 hdp->hd_phys_address = addr.minimum;
 928                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 929
 930                 if (hpet_is_known(hdp)) {
 931                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 932                                 __FUNCTION__, hdp->hd_phys_address);
 933                         iounmap(hdp->hd_address);
 934                         return -EBUSY;
 935                 }
 936         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 937                 struct acpi_resource_fixed_memory32 *fixmem32;
 938
 939                 fixmem32 = &res->data.fixed_memory32;
 940                 if (!fixmem32)
 941                         return -EINVAL;
 942
 943                 hdp->hd_phys_address = fixmem32->address;
 944                 hdp->hd_address = ioremap(fixmem32->address,
 945                                                 HPET_RANGE_SIZE);
 946
 947                 if (hpet_is_known(hdp)) {
 948                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 949                                 __FUNCTION__, hdp->hd_phys_address);
 950                         iounmap(hdp->hd_address);
 951                         return -EBUSY;
 952                 }
 953         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 954                 struct acpi_resource_extended_irq *irqp;
 955                 int i, irq;
 956
 957                 irqp = &res->data.extended_irq;
 958
 959                 for (i = 0; i < irqp->interrupt_count; i++) {
 960                         irq = acpi_register_gsi(irqp->interrupts[i],
 961                                       irqp->triggering, irqp->polarity);
 962                         if (irq < 0)
 963                                 return AE_ERROR;
 964
 965                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 966                         hdp->hd_nirqs++;
 967                 }
 968         }
 969
 970         return AE_OK;
 971 }
 972
 973 static int hpet_acpi_add(struct acpi_device *device)
 974 {
 975         acpi_status result;
 976         struct hpet_data data;
 977
 978         memset(&data, 0, sizeof(data));
 979
 980         result =
 981             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 982                                 hpet_resources, &data);
 983
 984         if (ACPI_FAILURE(result))
 985                 return -ENODEV;
 986
 987         if (!data.hd_address || !data.hd_nirqs) {
 988                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
 989                 return -ENODEV;
 990         }
 991
 992         return hpet_alloc(&data);
 993 }
 994
 995 static int hpet_acpi_remove(struct acpi_device *device, int type)
 996 {
 997         /* XXX need to unregister interpolator, dealloc mem, etc */
 998         return -EINVAL;
 999 }
1000
1001 static struct acpi_driver hpet_acpi_driver = {
1002         .name = "hpet",
1003         .ids = "PNP0103",
1004         .ops = {
1005                 .add = hpet_acpi_add,
1006                 .remove = hpet_acpi_remove,
1007                 },
1008 };
1009
1010 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1011
1012 static int __init hpet_init(void)
1013 {
1014         int result;
1015
1016         result = misc_register(&hpet_misc);
1017         if (result < 0)
1018                 return -ENODEV;
1019
1020         sysctl_header = register_sysctl_table(dev_root, 0);
1021
1022         result = acpi_bus_register_driver(&hpet_acpi_driver);
1023         if (result < 0) {
1024                 if (sysctl_header)
1025                         unregister_sysctl_table(sysctl_header);
1026                 misc_deregister(&hpet_misc);
1027                 return result;
1028         }
1029
1030         return 0;
1031 }
1032
1033 static void __exit hpet_exit(void)
1034 {
1035         acpi_bus_unregister_driver(&hpet_acpi_driver);
1036
1037         if (sysctl_header)
1038                 unregister_sysctl_table(sysctl_header);
1039         misc_deregister(&hpet_misc);
1040
1041         return;
1042 }
1043
1044 module_init(hpet_init);
1045 module_exit(hpet_exit);
1046 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1047 MODULE_LICENSE("GPL");