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/config.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/types.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/major.h>
  21 #include <linux/ioport.h>
  22 #include <linux/fcntl.h>
  23 #include <linux/init.h>
  24 #include <linux/poll.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/sysctl.h>
  28 #include <linux/wait.h>
  29 #include <linux/bcd.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/bitops.h>
  32
  33 #include <asm/current.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/system.h>
  36 #include <asm/io.h>
  37 #include <asm/irq.h>
  38 #include <asm/div64.h>
  39
  40 #include <linux/acpi.h>
  41 #include <acpi/acpi_bus.h>
  42 #include <linux/hpet.h>
  43
  44 /*
  45  * The High Precision Event Timer driver.
  46  * This driver is closely modelled after the rtc.c driver.
  47  * http://www.intel.com/hardwaredesign/hpetspec.htm
  48  */
  49 #define HPET_USER_FREQ  (64)
  50 #define HPET_DRIFT      (500)
  51
  52 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  53
  54 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  55
  56 /* A lock for concurrent access by app and isr hpet activity. */
  57 static DEFINE_SPINLOCK(hpet_lock);
  58 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  59 static DEFINE_SPINLOCK(hpet_task_lock);
  60
  61 #define HPET_DEV_NAME   (7)
  62
  63 struct hpet_dev {
  64         struct hpets *hd_hpets;
  65         struct hpet __iomem *hd_hpet;
  66         struct hpet_timer __iomem *hd_timer;
  67         unsigned long hd_ireqfreq;
  68         unsigned long hd_irqdata;
  69         wait_queue_head_t hd_waitqueue;
  70         struct fasync_struct *hd_async_queue;
  71         struct hpet_task *hd_task;
  72         unsigned int hd_flags;
  73         unsigned int hd_irq;
  74         unsigned int hd_hdwirq;
  75         char hd_name[HPET_DEV_NAME];
  76 };
  77
  78 struct hpets {
  79         struct hpets *hp_next;
  80         struct hpet __iomem *hp_hpet;
  81         unsigned long hp_hpet_phys;
  82         struct time_interpolator *hp_interpolator;
  83         unsigned long long hp_tick_freq;
  84         unsigned long hp_delta;
  85         unsigned int hp_ntimer;
  86         unsigned int hp_which;
  87         struct hpet_dev hp_dev[1];
  88 };
  89
  90 static struct hpets *hpets;
  91
  92 #define HPET_OPEN               0x0001
  93 #define HPET_IE                 0x0002  /* interrupt enabled */
  94 #define HPET_PERIODIC           0x0004
  95 #define HPET_SHARED_IRQ         0x0008
  96
  97 #if BITS_PER_LONG == 64
  98 #define write_counter(V, MC)    writeq(V, MC)
  99 #define read_counter(MC)        readq(MC)
 100 #else
 101 #define write_counter(V, MC)    writel(V, MC)
 102 #define read_counter(MC)        readl(MC)
 103 #endif
 104
 105 #ifndef readq
 106 static inline unsigned long long readq(void __iomem *addr)
 107 {
 108         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 109 }
 110 #endif
 111
 112 #ifndef writeq
 113 static inline void writeq(unsigned long long v, void __iomem *addr)
 114 {
 115         writel(v & 0xffffffff, addr);
 116         writel(v >> 32, addr + 4);
 117 }
 118 #endif
 119
 120 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
 121 {
 122         struct hpet_dev *devp;
 123         unsigned long isr;
 124
 125         devp = data;
 126         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 127
 128         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 129             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 130                 return IRQ_NONE;
 131
 132         spin_lock(&hpet_lock);
 133         devp->hd_irqdata++;
 134
 135         /*
 136          * For non-periodic timers, increment the accumulator.
 137          * This has the effect of treating non-periodic like periodic.
 138          */
 139         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 140                 unsigned long m, t;
 141
 142                 t = devp->hd_ireqfreq;
 143                 m = read_counter(&devp->hd_hpet->hpet_mc);
 144                 write_counter(t + m + devp->hd_hpets->hp_delta,
 145                               &devp->hd_timer->hpet_compare);
 146         }
 147
 148         if (devp->hd_flags & HPET_SHARED_IRQ)
 149                 writel(isr, &devp->hd_hpet->hpet_isr);
 150         spin_unlock(&hpet_lock);
 151
 152         spin_lock(&hpet_task_lock);
 153         if (devp->hd_task)
 154                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 155         spin_unlock(&hpet_task_lock);
 156
 157         wake_up_interruptible(&devp->hd_waitqueue);
 158
 159         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 160
 161         return IRQ_HANDLED;
 162 }
 163
 164 static int hpet_open(struct inode *inode, struct file *file)
 165 {
 166         struct hpet_dev *devp;
 167         struct hpets *hpetp;
 168         int i;
 169
 170         if (file->f_mode & FMODE_WRITE)
 171                 return -EINVAL;
 172
 173         spin_lock_irq(&hpet_lock);
 174
 175         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 176                 for (i = 0; i < hpetp->hp_ntimer; i++)
 177                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 178                             || hpetp->hp_dev[i].hd_task)
 179                                 continue;
 180                         else {
 181                                 devp = &hpetp->hp_dev[i];
 182                                 break;
 183                         }
 184
 185         if (!devp) {
 186                 spin_unlock_irq(&hpet_lock);
 187                 return -EBUSY;
 188         }
 189
 190         file->private_data = devp;
 191         devp->hd_irqdata = 0;
 192         devp->hd_flags |= HPET_OPEN;
 193         spin_unlock_irq(&hpet_lock);
 194
 195         return 0;
 196 }
 197
 198 static ssize_t
 199 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 200 {
 201         DECLARE_WAITQUEUE(wait, current);
 202         unsigned long data;
 203         ssize_t retval;
 204         struct hpet_dev *devp;
 205
 206         devp = file->private_data;
 207         if (!devp->hd_ireqfreq)
 208                 return -EIO;
 209
 210         if (count < sizeof(unsigned long))
 211                 return -EINVAL;
 212
 213         add_wait_queue(&devp->hd_waitqueue, &wait);
 214
 215         for ( ; ; ) {
 216                 set_current_state(TASK_INTERRUPTIBLE);
 217
 218                 spin_lock_irq(&hpet_lock);
 219                 data = devp->hd_irqdata;
 220                 devp->hd_irqdata = 0;
 221                 spin_unlock_irq(&hpet_lock);
 222
 223                 if (data)
 224                         break;
 225                 else if (file->f_flags & O_NONBLOCK) {
 226                         retval = -EAGAIN;
 227                         goto out;
 228                 } else if (signal_pending(current)) {
 229                         retval = -ERESTARTSYS;
 230                         goto out;
 231                 }
 232                 schedule();
 233         }
 234
 235         retval = put_user(data, (unsigned long __user *)buf);
 236         if (!retval)
 237                 retval = sizeof(unsigned long);
 238 out:
 239         __set_current_state(TASK_RUNNING);
 240         remove_wait_queue(&devp->hd_waitqueue, &wait);
 241
 242         return retval;
 243 }
 244
 245 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 246 {
 247         unsigned long v;
 248         struct hpet_dev *devp;
 249
 250         devp = file->private_data;
 251
 252         if (!devp->hd_ireqfreq)
 253                 return 0;
 254
 255         poll_wait(file, &devp->hd_waitqueue, wait);
 256
 257         spin_lock_irq(&hpet_lock);
 258         v = devp->hd_irqdata;
 259         spin_unlock_irq(&hpet_lock);
 260
 261         if (v != 0)
 262                 return POLLIN | POLLRDNORM;
 263
 264         return 0;
 265 }
 266
 267 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 268 {
 269 #ifdef  CONFIG_HPET_MMAP
 270         struct hpet_dev *devp;
 271         unsigned long addr;
 272
 273         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 274                 return -EINVAL;
 275
 276         devp = file->private_data;
 277         addr = devp->hd_hpets->hp_hpet_phys;
 278
 279         if (addr & (PAGE_SIZE - 1))
 280                 return -ENOSYS;
 281
 282         vma->vm_flags |= VM_IO;
 283         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 284
 285         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 286                                         PAGE_SIZE, vma->vm_page_prot)) {
 287                 printk(KERN_ERR "remap_pfn_range failed in hpet.c\n");
 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                                                 ? SA_SHIRQ : SA_INTERRUPT;
 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 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 EXPORT_SYMBOL(hpet_alloc);
 569 EXPORT_SYMBOL(hpet_register);
 570 EXPORT_SYMBOL(hpet_unregister);
 571 EXPORT_SYMBOL(hpet_control);
 572
 573 int hpet_register(struct hpet_task *tp, int periodic)
 574 {
 575         unsigned int i;
 576         u64 mask;
 577         struct hpet_timer __iomem *timer;
 578         struct hpet_dev *devp;
 579         struct hpets *hpetp;
 580
 581         switch (periodic) {
 582         case 1:
 583                 mask = Tn_PER_INT_CAP_MASK;
 584                 break;
 585         case 0:
 586                 mask = 0;
 587                 break;
 588         default:
 589                 return -EINVAL;
 590         }
 591
 592         tp->ht_opaque = NULL;
 593
 594         spin_lock_irq(&hpet_task_lock);
 595         spin_lock(&hpet_lock);
 596
 597         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 598                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
 599                      i < hpetp->hp_ntimer; i++, timer++) {
 600                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
 601                             != mask)
 602                                 continue;
 603
 604                         devp = &hpetp->hp_dev[i];
 605
 606                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
 607                                 devp = NULL;
 608                                 continue;
 609                         }
 610
 611                         tp->ht_opaque = devp;
 612                         devp->hd_task = tp;
 613                         break;
 614                 }
 615
 616         spin_unlock(&hpet_lock);
 617         spin_unlock_irq(&hpet_task_lock);
 618
 619         if (tp->ht_opaque)
 620                 return 0;
 621         else
 622                 return -EBUSY;
 623 }
 624
 625 static inline int hpet_tpcheck(struct hpet_task *tp)
 626 {
 627         struct hpet_dev *devp;
 628         struct hpets *hpetp;
 629
 630         devp = tp->ht_opaque;
 631
 632         if (!devp)
 633                 return -ENXIO;
 634
 635         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 636                 if (devp >= hpetp->hp_dev
 637                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 638                     && devp->hd_hpet == hpetp->hp_hpet)
 639                         return 0;
 640
 641         return -ENXIO;
 642 }
 643
 644 int hpet_unregister(struct hpet_task *tp)
 645 {
 646         struct hpet_dev *devp;
 647         struct hpet_timer __iomem *timer;
 648         int err;
 649
 650         if ((err = hpet_tpcheck(tp)))
 651                 return err;
 652
 653         spin_lock_irq(&hpet_task_lock);
 654         spin_lock(&hpet_lock);
 655
 656         devp = tp->ht_opaque;
 657         if (devp->hd_task != tp) {
 658                 spin_unlock(&hpet_lock);
 659                 spin_unlock_irq(&hpet_task_lock);
 660                 return -ENXIO;
 661         }
 662
 663         timer = devp->hd_timer;
 664         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 665                &timer->hpet_config);
 666         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 667         devp->hd_task = NULL;
 668         spin_unlock(&hpet_lock);
 669         spin_unlock_irq(&hpet_task_lock);
 670
 671         return 0;
 672 }
 673
 674 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
 675 {
 676         struct hpet_dev *devp;
 677         int err;
 678
 679         if ((err = hpet_tpcheck(tp)))
 680                 return err;
 681
 682         spin_lock_irq(&hpet_lock);
 683         devp = tp->ht_opaque;
 684         if (devp->hd_task != tp) {
 685                 spin_unlock_irq(&hpet_lock);
 686                 return -ENXIO;
 687         }
 688         spin_unlock_irq(&hpet_lock);
 689         return hpet_ioctl_common(devp, cmd, arg, 1);
 690 }
 691
 692 static ctl_table hpet_table[] = {
 693         {
 694          .ctl_name = 1,
 695          .procname = "max-user-freq",
 696          .data = &hpet_max_freq,
 697          .maxlen = sizeof(int),
 698          .mode = 0644,
 699          .proc_handler = &proc_dointvec,
 700          },
 701         {.ctl_name = 0}
 702 };
 703
 704 static ctl_table hpet_root[] = {
 705         {
 706          .ctl_name = 1,
 707          .procname = "hpet",
 708          .maxlen = 0,
 709          .mode = 0555,
 710          .child = hpet_table,
 711          },
 712         {.ctl_name = 0}
 713 };
 714
 715 static ctl_table dev_root[] = {
 716         {
 717          .ctl_name = CTL_DEV,
 718          .procname = "dev",
 719          .maxlen = 0,
 720          .mode = 0555,
 721          .child = hpet_root,
 722          },
 723         {.ctl_name = 0}
 724 };
 725
 726 static struct ctl_table_header *sysctl_header;
 727
 728 static void hpet_register_interpolator(struct hpets *hpetp)
 729 {
 730 #ifdef  CONFIG_TIME_INTERPOLATION
 731         struct time_interpolator *ti;
 732
 733         ti = kmalloc(sizeof(*ti), GFP_KERNEL);
 734         if (!ti)
 735                 return;
 736
 737         memset(ti, 0, sizeof(*ti));
 738         ti->source = TIME_SOURCE_MMIO64;
 739         ti->shift = 10;
 740         ti->addr = &hpetp->hp_hpet->hpet_mc;
 741         ti->frequency = hpetp->hp_tick_freq;
 742         ti->drift = HPET_DRIFT;
 743         ti->mask = -1;
 744
 745         hpetp->hp_interpolator = ti;
 746         register_time_interpolator(ti);
 747 #endif
 748 }
 749
 750 /*
 751  * Adjustment for when arming the timer with
 752  * initial conditions.  That is, main counter
 753  * ticks expired before interrupts are enabled.
 754  */
 755 #define TICK_CALIBRATE  (1000UL)
 756
 757 static unsigned long hpet_calibrate(struct hpets *hpetp)
 758 {
 759         struct hpet_timer __iomem *timer = NULL;
 760         unsigned long t, m, count, i, flags, start;
 761         struct hpet_dev *devp;
 762         int j;
 763         struct hpet __iomem *hpet;
 764
 765         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 766                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 767                         timer = devp->hd_timer;
 768                         break;
 769                 }
 770
 771         if (!timer)
 772                 return 0;
 773
 774         hpet = hpetp->hp_hpet;
 775         t = read_counter(&timer->hpet_compare);
 776
 777         i = 0;
 778         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 779
 780         local_irq_save(flags);
 781
 782         start = read_counter(&hpet->hpet_mc);
 783
 784         do {
 785                 m = read_counter(&hpet->hpet_mc);
 786                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 787         } while (i++, (m - start) < count);
 788
 789         local_irq_restore(flags);
 790
 791         return (m - start) / i;
 792 }
 793
 794 int hpet_alloc(struct hpet_data *hdp)
 795 {
 796         u64 cap, mcfg;
 797         struct hpet_dev *devp;
 798         u32 i, ntimer;
 799         struct hpets *hpetp;
 800         size_t siz;
 801         struct hpet __iomem *hpet;
 802         static struct hpets *last = (struct hpets *)0;
 803         unsigned long period;
 804         unsigned long long temp;
 805
 806         /*
 807          * hpet_alloc can be called by platform dependent code.
 808          * if platform dependent code has allocated the hpet
 809          * ACPI also reports hpet, then we catch it here.
 810          */
 811         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 812                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) {
 813                         printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 814                                 __FUNCTION__);
 815                         return 0;
 816                 }
 817
 818         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 819                                       sizeof(struct hpet_dev));
 820
 821         hpetp = kmalloc(siz, GFP_KERNEL);
 822
 823         if (!hpetp)
 824                 return -ENOMEM;
 825
 826         memset(hpetp, 0, siz);
 827
 828         hpetp->hp_which = hpet_nhpet++;
 829         hpetp->hp_hpet = hdp->hd_address;
 830         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 831
 832         hpetp->hp_ntimer = hdp->hd_nirqs;
 833
 834         for (i = 0; i < hdp->hd_nirqs; i++)
 835                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 836
 837         hpet = hpetp->hp_hpet;
 838
 839         cap = readq(&hpet->hpet_cap);
 840
 841         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 842
 843         if (hpetp->hp_ntimer != ntimer) {
 844                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 845                        " with number of timers\n");
 846                 kfree(hpetp);
 847                 return -ENODEV;
 848         }
 849
 850         if (last)
 851                 last->hp_next = hpetp;
 852         else
 853                 hpets = hpetp;
 854
 855         last = hpetp;
 856
 857         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 858                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 859         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 860         temp += period >> 1; /* round */
 861         do_div(temp, period);
 862         hpetp->hp_tick_freq = temp; /* ticks per second */
 863
 864         printk(KERN_INFO "hpet%d: at MMIO 0x%lx (virtual 0x%p), IRQ%s",
 865                 hpetp->hp_which, hdp->hd_phys_address, hdp->hd_address,
 866                 hpetp->hp_ntimer > 1 ? "s" : "");
 867         for (i = 0; i < hpetp->hp_ntimer; i++)
 868                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 869         printk("\n");
 870
 871         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
 872                hpetp->hp_which, hpetp->hp_ntimer,
 873                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
 874
 875         mcfg = readq(&hpet->hpet_config);
 876         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 877                 write_counter(0L, &hpet->hpet_mc);
 878                 mcfg |= HPET_ENABLE_CNF_MASK;
 879                 writeq(mcfg, &hpet->hpet_config);
 880         }
 881
 882         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 883                 struct hpet_timer __iomem *timer;
 884
 885                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 886
 887                 devp->hd_hpets = hpetp;
 888                 devp->hd_hpet = hpet;
 889                 devp->hd_timer = timer;
 890
 891                 /*
 892                  * If the timer was reserved by platform code,
 893                  * then make timer unavailable for opens.
 894                  */
 895                 if (hdp->hd_state & (1 << i)) {
 896                         devp->hd_flags = HPET_OPEN;
 897                         continue;
 898                 }
 899
 900                 init_waitqueue_head(&devp->hd_waitqueue);
 901         }
 902
 903         hpetp->hp_delta = hpet_calibrate(hpetp);
 904         hpet_register_interpolator(hpetp);
 905
 906         return 0;
 907 }
 908
 909 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 910 {
 911         struct hpet_data *hdp;
 912         acpi_status status;
 913         struct acpi_resource_address64 addr;
 914         struct hpets *hpetp;
 915
 916         hdp = data;
 917
 918         status = acpi_resource_to_address64(res, &addr);
 919
 920         if (ACPI_SUCCESS(status)) {
 921                 unsigned long size;
 922
 923                 size = addr.max_address_range - addr.min_address_range + 1;
 924                 hdp->hd_phys_address = addr.min_address_range;
 925                 hdp->hd_address = ioremap(addr.min_address_range, size);
 926
 927                 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 928                         if (hpetp->hp_hpet_phys == hdp->hd_phys_address) {
 929                                 printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 930                                         __FUNCTION__, hdp->hd_phys_address);
 931                                 iounmap(hdp->hd_address);
 932                                 return -EBUSY;
 933                         }
 934         } else if (res->id == ACPI_RSTYPE_FIXED_MEM32) {
 935                 struct acpi_resource_fixed_mem32 *fixmem32;
 936
 937                 fixmem32 = &res->data.fixed_memory32;
 938                 if (!fixmem32)
 939                         return -EINVAL;
 940
 941                 hdp->hd_phys_address = fixmem32->range_base_address;
 942                 hdp->hd_address = ioremap(fixmem32->range_base_address,
 943                                                 HPET_RANGE_SIZE);
 944
 945                 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 946                         if (hpetp->hp_hpet_phys == hdp->hd_phys_address) {
 947                                 printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 948                                         __FUNCTION__, hdp->hd_phys_address);
 949                                 iounmap(hdp->hd_address);
 950                                 return -EBUSY;
 951                         }
 952         } else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
 953                 struct acpi_resource_ext_irq *irqp;
 954                 int i;
 955
 956                 irqp = &res->data.extended_irq;
 957
 958                 if (irqp->number_of_interrupts > 0) {
 959                         hdp->hd_nirqs = irqp->number_of_interrupts;
 960
 961                         for (i = 0; i < hdp->hd_nirqs; i++) {
 962                                 int rc =
 963                                     acpi_register_gsi(irqp->interrupts[i],
 964                                                       irqp->edge_level,
 965                                                       irqp->active_high_low);
 966                                 if (rc < 0)
 967                                         return AE_ERROR;
 968                                 hdp->hd_irq[i] = rc;
 969                         }
 970                 }
 971         }
 972
 973         return AE_OK;
 974 }
 975
 976 static int hpet_acpi_add(struct acpi_device *device)
 977 {
 978         acpi_status result;
 979         struct hpet_data data;
 980
 981         memset(&data, 0, sizeof(data));
 982
 983         result =
 984             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 985                                 hpet_resources, &data);
 986
 987         if (ACPI_FAILURE(result))
 988                 return -ENODEV;
 989
 990         if (!data.hd_address || !data.hd_nirqs) {
 991                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
 992                 return -ENODEV;
 993         }
 994
 995         return hpet_alloc(&data);
 996 }
 997
 998 static int hpet_acpi_remove(struct acpi_device *device, int type)
 999 {
1000         /* XXX need to unregister interpolator, dealloc mem, etc */
1001         return -EINVAL;
1002 }
1003
1004 static struct acpi_driver hpet_acpi_driver = {
1005         .name = "hpet",
1006         .ids = "PNP0103",
1007         .ops = {
1008                 .add = hpet_acpi_add,
1009                 .remove = hpet_acpi_remove,
1010                 },
1011 };
1012
1013 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1014
1015 static int __init hpet_init(void)
1016 {
1017         int result;
1018
1019         result = misc_register(&hpet_misc);
1020         if (result < 0)
1021                 return -ENODEV;
1022
1023         sysctl_header = register_sysctl_table(dev_root, 0);
1024
1025         result = acpi_bus_register_driver(&hpet_acpi_driver);
1026         if (result < 0) {
1027                 if (sysctl_header)
1028                         unregister_sysctl_table(sysctl_header);
1029                 misc_deregister(&hpet_misc);
1030                 return result;
1031         }
1032
1033         return 0;
1034 }
1035
1036 static void __exit hpet_exit(void)
1037 {
1038         acpi_bus_unregister_driver(&hpet_acpi_driver);
1039
1040         if (sysctl_header)
1041                 unregister_sysctl_table(sysctl_header);
1042         misc_deregister(&hpet_misc);
1043
1044         return;
1045 }
1046
1047 module_init(hpet_init);
1048 module_exit(hpet_exit);
1049 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1050 MODULE_LICENSE("GPL");