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/smp_lock.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/mm.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/sysctl.h>
  29 #include <linux/wait.h>
  30 #include <linux/bcd.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/bitops.h>
  33 #include <linux/clocksource.h>
  34
  35 #include <asm/current.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/system.h>
  38 #include <asm/io.h>
  39 #include <asm/irq.h>
  40 #include <asm/div64.h>
  41
  42 #include <linux/acpi.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <linux/hpet.h>
  45
  46 /*
  47  * The High Precision Event Timer driver.
  48  * This driver is closely modelled after the rtc.c driver.
  49  * http://www.intel.com/hardwaredesign/hpetspec.htm
  50  */
  51 #define HPET_USER_FREQ  (64)
  52 #define HPET_DRIFT      (500)
  53
  54 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  55
  56 #if BITS_PER_LONG == 64
  57 #define write_counter(V, MC)    writeq(V, MC)
  58 #define read_counter(MC)        readq(MC)
  59 #else
  60 #define write_counter(V, MC)    writel(V, MC)
  61 #define read_counter(MC)        readl(MC)
  62 #endif
  63
  64 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  65
  66 /* This clocksource driver currently only works on ia64 */
  67 #ifdef CONFIG_IA64
  68 static void __iomem *hpet_mctr;
  69
  70 static cycle_t read_hpet(void)
  71 {
  72         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
  73 }
  74
  75 static struct clocksource clocksource_hpet = {
  76         .name           = "hpet",
  77         .rating         = 250,
  78         .read           = read_hpet,
  79         .mask           = CLOCKSOURCE_MASK(64),
  80         .mult           = 0, /*to be caluclated*/
  81         .shift          = 10,
  82         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  83 };
  84 static struct clocksource *hpet_clocksource;
  85 #endif
  86
  87 /* A lock for concurrent access by app and isr hpet activity. */
  88 static DEFINE_SPINLOCK(hpet_lock);
  89 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  90 static DEFINE_SPINLOCK(hpet_task_lock);
  91
  92 #define HPET_DEV_NAME   (7)
  93
  94 struct hpet_dev {
  95         struct hpets *hd_hpets;
  96         struct hpet __iomem *hd_hpet;
  97         struct hpet_timer __iomem *hd_timer;
  98         unsigned long hd_ireqfreq;
  99         unsigned long hd_irqdata;
 100         wait_queue_head_t hd_waitqueue;
 101         struct fasync_struct *hd_async_queue;
 102         struct hpet_task *hd_task;
 103         unsigned int hd_flags;
 104         unsigned int hd_irq;
 105         unsigned int hd_hdwirq;
 106         char hd_name[HPET_DEV_NAME];
 107 };
 108
 109 struct hpets {
 110         struct hpets *hp_next;
 111         struct hpet __iomem *hp_hpet;
 112         unsigned long hp_hpet_phys;
 113         struct clocksource *hp_clocksource;
 114         unsigned long long hp_tick_freq;
 115         unsigned long hp_delta;
 116         unsigned int hp_ntimer;
 117         unsigned int hp_which;
 118         struct hpet_dev hp_dev[1];
 119 };
 120
 121 static struct hpets *hpets;
 122
 123 #define HPET_OPEN               0x0001
 124 #define HPET_IE                 0x0002  /* interrupt enabled */
 125 #define HPET_PERIODIC           0x0004
 126 #define HPET_SHARED_IRQ         0x0008
 127
 128
 129 #ifndef readq
 130 static inline unsigned long long readq(void __iomem *addr)
 131 {
 132         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 133 }
 134 #endif
 135
 136 #ifndef writeq
 137 static inline void writeq(unsigned long long v, void __iomem *addr)
 138 {
 139         writel(v & 0xffffffff, addr);
 140         writel(v >> 32, addr + 4);
 141 }
 142 #endif
 143
 144 static irqreturn_t hpet_interrupt(int irq, void *data)
 145 {
 146         struct hpet_dev *devp;
 147         unsigned long isr;
 148
 149         devp = data;
 150         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 151
 152         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 153             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 154                 return IRQ_NONE;
 155
 156         spin_lock(&hpet_lock);
 157         devp->hd_irqdata++;
 158
 159         /*
 160          * For non-periodic timers, increment the accumulator.
 161          * This has the effect of treating non-periodic like periodic.
 162          */
 163         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 164                 unsigned long m, t;
 165
 166                 t = devp->hd_ireqfreq;
 167                 m = read_counter(&devp->hd_hpet->hpet_mc);
 168                 write_counter(t + m + devp->hd_hpets->hp_delta,
 169                               &devp->hd_timer->hpet_compare);
 170         }
 171
 172         if (devp->hd_flags & HPET_SHARED_IRQ)
 173                 writel(isr, &devp->hd_hpet->hpet_isr);
 174         spin_unlock(&hpet_lock);
 175
 176         spin_lock(&hpet_task_lock);
 177         if (devp->hd_task)
 178                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 179         spin_unlock(&hpet_task_lock);
 180
 181         wake_up_interruptible(&devp->hd_waitqueue);
 182
 183         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 184
 185         return IRQ_HANDLED;
 186 }
 187
 188 static void hpet_timer_set_irq(struct hpet_dev *devp)
 189 {
 190         unsigned long v;
 191         int irq, gsi;
 192         struct hpet_timer __iomem *timer;
 193
 194         spin_lock_irq(&hpet_lock);
 195         if (devp->hd_hdwirq) {
 196                 spin_unlock_irq(&hpet_lock);
 197                 return;
 198         }
 199
 200         timer = devp->hd_timer;
 201
 202         /* we prefer level triggered mode */
 203         v = readl(&timer->hpet_config);
 204         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
 205                 v |= Tn_INT_TYPE_CNF_MASK;
 206                 writel(v, &timer->hpet_config);
 207         }
 208         spin_unlock_irq(&hpet_lock);
 209
 210         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
 211                                  Tn_INT_ROUTE_CAP_SHIFT;
 212
 213         /*
 214          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
 215          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
 216          */
 217         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 218                 v &= ~0xf3df;
 219         else
 220                 v &= ~0xffff;
 221
 222         for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ;
 223                 irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) {
 224
 225                 if (irq >= NR_IRQS) {
 226                         irq = HPET_MAX_IRQ;
 227                         break;
 228                 }
 229
 230                 gsi = acpi_register_gsi(irq, ACPI_LEVEL_SENSITIVE,
 231                                         ACPI_ACTIVE_LOW);
 232                 if (gsi > 0)
 233                         break;
 234
 235                 /* FIXME: Setup interrupt source table */
 236         }
 237
 238         if (irq < HPET_MAX_IRQ) {
 239                 spin_lock_irq(&hpet_lock);
 240                 v = readl(&timer->hpet_config);
 241                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
 242                 writel(v, &timer->hpet_config);
 243                 devp->hd_hdwirq = gsi;
 244                 spin_unlock_irq(&hpet_lock);
 245         }
 246         return;
 247 }
 248
 249 static int hpet_open(struct inode *inode, struct file *file)
 250 {
 251         struct hpet_dev *devp;
 252         struct hpets *hpetp;
 253         int i;
 254
 255         if (file->f_mode & FMODE_WRITE)
 256                 return -EINVAL;
 257
 258         lock_kernel();
 259         spin_lock_irq(&hpet_lock);
 260
 261         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 262                 for (i = 0; i < hpetp->hp_ntimer; i++)
 263                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 264                             || hpetp->hp_dev[i].hd_task)
 265                                 continue;
 266                         else {
 267                                 devp = &hpetp->hp_dev[i];
 268                                 break;
 269                         }
 270
 271         if (!devp) {
 272                 spin_unlock_irq(&hpet_lock);
 273                 unlock_kernel();
 274                 return -EBUSY;
 275         }
 276
 277         file->private_data = devp;
 278         devp->hd_irqdata = 0;
 279         devp->hd_flags |= HPET_OPEN;
 280         spin_unlock_irq(&hpet_lock);
 281         unlock_kernel();
 282
 283         hpet_timer_set_irq(devp);
 284
 285         return 0;
 286 }
 287
 288 static ssize_t
 289 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 290 {
 291         DECLARE_WAITQUEUE(wait, current);
 292         unsigned long data;
 293         ssize_t retval;
 294         struct hpet_dev *devp;
 295
 296         devp = file->private_data;
 297         if (!devp->hd_ireqfreq)
 298                 return -EIO;
 299
 300         if (count < sizeof(unsigned long))
 301                 return -EINVAL;
 302
 303         add_wait_queue(&devp->hd_waitqueue, &wait);
 304
 305         for ( ; ; ) {
 306                 set_current_state(TASK_INTERRUPTIBLE);
 307
 308                 spin_lock_irq(&hpet_lock);
 309                 data = devp->hd_irqdata;
 310                 devp->hd_irqdata = 0;
 311                 spin_unlock_irq(&hpet_lock);
 312
 313                 if (data)
 314                         break;
 315                 else if (file->f_flags & O_NONBLOCK) {
 316                         retval = -EAGAIN;
 317                         goto out;
 318                 } else if (signal_pending(current)) {
 319                         retval = -ERESTARTSYS;
 320                         goto out;
 321                 }
 322                 schedule();
 323         }
 324
 325         retval = put_user(data, (unsigned long __user *)buf);
 326         if (!retval)
 327                 retval = sizeof(unsigned long);
 328 out:
 329         __set_current_state(TASK_RUNNING);
 330         remove_wait_queue(&devp->hd_waitqueue, &wait);
 331
 332         return retval;
 333 }
 334
 335 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 336 {
 337         unsigned long v;
 338         struct hpet_dev *devp;
 339
 340         devp = file->private_data;
 341
 342         if (!devp->hd_ireqfreq)
 343                 return 0;
 344
 345         poll_wait(file, &devp->hd_waitqueue, wait);
 346
 347         spin_lock_irq(&hpet_lock);
 348         v = devp->hd_irqdata;
 349         spin_unlock_irq(&hpet_lock);
 350
 351         if (v != 0)
 352                 return POLLIN | POLLRDNORM;
 353
 354         return 0;
 355 }
 356
 357 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 358 {
 359 #ifdef  CONFIG_HPET_MMAP
 360         struct hpet_dev *devp;
 361         unsigned long addr;
 362
 363         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 364                 return -EINVAL;
 365
 366         devp = file->private_data;
 367         addr = devp->hd_hpets->hp_hpet_phys;
 368
 369         if (addr & (PAGE_SIZE - 1))
 370                 return -ENOSYS;
 371
 372         vma->vm_flags |= VM_IO;
 373         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 374
 375         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 376                                         PAGE_SIZE, vma->vm_page_prot)) {
 377                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
 378                         __func__);
 379                 return -EAGAIN;
 380         }
 381
 382         return 0;
 383 #else
 384         return -ENOSYS;
 385 #endif
 386 }
 387
 388 static int hpet_fasync(int fd, struct file *file, int on)
 389 {
 390         struct hpet_dev *devp;
 391
 392         devp = file->private_data;
 393
 394         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 395                 return 0;
 396         else
 397                 return -EIO;
 398 }
 399
 400 static int hpet_release(struct inode *inode, struct file *file)
 401 {
 402         struct hpet_dev *devp;
 403         struct hpet_timer __iomem *timer;
 404         int irq = 0;
 405
 406         devp = file->private_data;
 407         timer = devp->hd_timer;
 408
 409         spin_lock_irq(&hpet_lock);
 410
 411         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 412                &timer->hpet_config);
 413
 414         irq = devp->hd_irq;
 415         devp->hd_irq = 0;
 416
 417         devp->hd_ireqfreq = 0;
 418
 419         if (devp->hd_flags & HPET_PERIODIC
 420             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 421                 unsigned long v;
 422
 423                 v = readq(&timer->hpet_config);
 424                 v ^= Tn_TYPE_CNF_MASK;
 425                 writeq(v, &timer->hpet_config);
 426         }
 427
 428         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 429         spin_unlock_irq(&hpet_lock);
 430
 431         if (irq)
 432                 free_irq(irq, devp);
 433
 434         if (file->f_flags & FASYNC)
 435                 hpet_fasync(-1, file, 0);
 436
 437         file->private_data = NULL;
 438         return 0;
 439 }
 440
 441 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 442
 443 static int
 444 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 445            unsigned long arg)
 446 {
 447         struct hpet_dev *devp;
 448
 449         devp = file->private_data;
 450         return hpet_ioctl_common(devp, cmd, arg, 0);
 451 }
 452
 453 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 454 {
 455         struct hpet_timer __iomem *timer;
 456         struct hpet __iomem *hpet;
 457         struct hpets *hpetp;
 458         int irq;
 459         unsigned long g, v, t, m;
 460         unsigned long flags, isr;
 461
 462         timer = devp->hd_timer;
 463         hpet = devp->hd_hpet;
 464         hpetp = devp->hd_hpets;
 465
 466         if (!devp->hd_ireqfreq)
 467                 return -EIO;
 468
 469         spin_lock_irq(&hpet_lock);
 470
 471         if (devp->hd_flags & HPET_IE) {
 472                 spin_unlock_irq(&hpet_lock);
 473                 return -EBUSY;
 474         }
 475
 476         devp->hd_flags |= HPET_IE;
 477
 478         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 479                 devp->hd_flags |= HPET_SHARED_IRQ;
 480         spin_unlock_irq(&hpet_lock);
 481
 482         irq = devp->hd_hdwirq;
 483
 484         if (irq) {
 485                 unsigned long irq_flags;
 486
 487                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 488                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 489                                                 ? IRQF_SHARED : IRQF_DISABLED;
 490                 if (request_irq(irq, hpet_interrupt, irq_flags,
 491                                 devp->hd_name, (void *)devp)) {
 492                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 493                         irq = 0;
 494                 }
 495         }
 496
 497         if (irq == 0) {
 498                 spin_lock_irq(&hpet_lock);
 499                 devp->hd_flags ^= HPET_IE;
 500                 spin_unlock_irq(&hpet_lock);
 501                 return -EIO;
 502         }
 503
 504         devp->hd_irq = irq;
 505         t = devp->hd_ireqfreq;
 506         v = readq(&timer->hpet_config);
 507         g = v | Tn_INT_ENB_CNF_MASK;
 508
 509         if (devp->hd_flags & HPET_PERIODIC) {
 510                 write_counter(t, &timer->hpet_compare);
 511                 g |= Tn_TYPE_CNF_MASK;
 512                 v |= Tn_TYPE_CNF_MASK;
 513                 writeq(v, &timer->hpet_config);
 514                 v |= Tn_VAL_SET_CNF_MASK;
 515                 writeq(v, &timer->hpet_config);
 516                 local_irq_save(flags);
 517                 m = read_counter(&hpet->hpet_mc);
 518                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 519         } else {
 520                 local_irq_save(flags);
 521                 m = read_counter(&hpet->hpet_mc);
 522                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 523         }
 524
 525         if (devp->hd_flags & HPET_SHARED_IRQ) {
 526                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 527                 writel(isr, &hpet->hpet_isr);
 528         }
 529         writeq(g, &timer->hpet_config);
 530         local_irq_restore(flags);
 531
 532         return 0;
 533 }
 534
 535 /* converts Hz to number of timer ticks */
 536 static inline unsigned long hpet_time_div(struct hpets *hpets,
 537                                           unsigned long dis)
 538 {
 539         unsigned long long m;
 540
 541         m = hpets->hp_tick_freq + (dis >> 1);
 542         do_div(m, dis);
 543         return (unsigned long)m;
 544 }
 545
 546 static int
 547 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 548 {
 549         struct hpet_timer __iomem *timer;
 550         struct hpet __iomem *hpet;
 551         struct hpets *hpetp;
 552         int err;
 553         unsigned long v;
 554
 555         switch (cmd) {
 556         case HPET_IE_OFF:
 557         case HPET_INFO:
 558         case HPET_EPI:
 559         case HPET_DPI:
 560         case HPET_IRQFREQ:
 561                 timer = devp->hd_timer;
 562                 hpet = devp->hd_hpet;
 563                 hpetp = devp->hd_hpets;
 564                 break;
 565         case HPET_IE_ON:
 566                 return hpet_ioctl_ieon(devp);
 567         default:
 568                 return -EINVAL;
 569         }
 570
 571         err = 0;
 572
 573         switch (cmd) {
 574         case HPET_IE_OFF:
 575                 if ((devp->hd_flags & HPET_IE) == 0)
 576                         break;
 577                 v = readq(&timer->hpet_config);
 578                 v &= ~Tn_INT_ENB_CNF_MASK;
 579                 writeq(v, &timer->hpet_config);
 580                 if (devp->hd_irq) {
 581                         free_irq(devp->hd_irq, devp);
 582                         devp->hd_irq = 0;
 583                 }
 584                 devp->hd_flags ^= HPET_IE;
 585                 break;
 586         case HPET_INFO:
 587                 {
 588                         struct hpet_info info;
 589
 590                         if (devp->hd_ireqfreq)
 591                                 info.hi_ireqfreq =
 592                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 593                         else
 594                                 info.hi_ireqfreq = 0;
 595                         info.hi_flags =
 596                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 597                         info.hi_hpet = hpetp->hp_which;
 598                         info.hi_timer = devp - hpetp->hp_dev;
 599                         if (kernel)
 600                                 memcpy((void *)arg, &info, sizeof(info));
 601                         else
 602                                 if (copy_to_user((void __user *)arg, &info,
 603                                                  sizeof(info)))
 604                                         err = -EFAULT;
 605                         break;
 606                 }
 607         case HPET_EPI:
 608                 v = readq(&timer->hpet_config);
 609                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 610                         err = -ENXIO;
 611                         break;
 612                 }
 613                 devp->hd_flags |= HPET_PERIODIC;
 614                 break;
 615         case HPET_DPI:
 616                 v = readq(&timer->hpet_config);
 617                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 618                         err = -ENXIO;
 619                         break;
 620                 }
 621                 if (devp->hd_flags & HPET_PERIODIC &&
 622                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 623                         v = readq(&timer->hpet_config);
 624                         v ^= Tn_TYPE_CNF_MASK;
 625                         writeq(v, &timer->hpet_config);
 626                 }
 627                 devp->hd_flags &= ~HPET_PERIODIC;
 628                 break;
 629         case HPET_IRQFREQ:
 630                 if (!kernel && (arg > hpet_max_freq) &&
 631                     !capable(CAP_SYS_RESOURCE)) {
 632                         err = -EACCES;
 633                         break;
 634                 }
 635
 636                 if (!arg) {
 637                         err = -EINVAL;
 638                         break;
 639                 }
 640
 641                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 642         }
 643
 644         return err;
 645 }
 646
 647 static const struct file_operations hpet_fops = {
 648         .owner = THIS_MODULE,
 649         .llseek = no_llseek,
 650         .read = hpet_read,
 651         .poll = hpet_poll,
 652         .ioctl = hpet_ioctl,
 653         .open = hpet_open,
 654         .release = hpet_release,
 655         .fasync = hpet_fasync,
 656         .mmap = hpet_mmap,
 657 };
 658
 659 static int hpet_is_known(struct hpet_data *hdp)
 660 {
 661         struct hpets *hpetp;
 662
 663         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 664                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 665                         return 1;
 666
 667         return 0;
 668 }
 669
 670 static inline int hpet_tpcheck(struct hpet_task *tp)
 671 {
 672         struct hpet_dev *devp;
 673         struct hpets *hpetp;
 674
 675         devp = tp->ht_opaque;
 676
 677         if (!devp)
 678                 return -ENXIO;
 679
 680         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 681                 if (devp >= hpetp->hp_dev
 682                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 683                     && devp->hd_hpet == hpetp->hp_hpet)
 684                         return 0;
 685
 686         return -ENXIO;
 687 }
 688
 689 #if 0
 690 int hpet_unregister(struct hpet_task *tp)
 691 {
 692         struct hpet_dev *devp;
 693         struct hpet_timer __iomem *timer;
 694         int err;
 695
 696         if ((err = hpet_tpcheck(tp)))
 697                 return err;
 698
 699         spin_lock_irq(&hpet_task_lock);
 700         spin_lock(&hpet_lock);
 701
 702         devp = tp->ht_opaque;
 703         if (devp->hd_task != tp) {
 704                 spin_unlock(&hpet_lock);
 705                 spin_unlock_irq(&hpet_task_lock);
 706                 return -ENXIO;
 707         }
 708
 709         timer = devp->hd_timer;
 710         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 711                &timer->hpet_config);
 712         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 713         devp->hd_task = NULL;
 714         spin_unlock(&hpet_lock);
 715         spin_unlock_irq(&hpet_task_lock);
 716
 717         return 0;
 718 }
 719 #endif  /*  0  */
 720
 721 static ctl_table hpet_table[] = {
 722         {
 723          .ctl_name = CTL_UNNUMBERED,
 724          .procname = "max-user-freq",
 725          .data = &hpet_max_freq,
 726          .maxlen = sizeof(int),
 727          .mode = 0644,
 728          .proc_handler = &proc_dointvec,
 729          },
 730         {.ctl_name = 0}
 731 };
 732
 733 static ctl_table hpet_root[] = {
 734         {
 735          .ctl_name = CTL_UNNUMBERED,
 736          .procname = "hpet",
 737          .maxlen = 0,
 738          .mode = 0555,
 739          .child = hpet_table,
 740          },
 741         {.ctl_name = 0}
 742 };
 743
 744 static ctl_table dev_root[] = {
 745         {
 746          .ctl_name = CTL_DEV,
 747          .procname = "dev",
 748          .maxlen = 0,
 749          .mode = 0555,
 750          .child = hpet_root,
 751          },
 752         {.ctl_name = 0}
 753 };
 754
 755 static struct ctl_table_header *sysctl_header;
 756
 757 /*
 758  * Adjustment for when arming the timer with
 759  * initial conditions.  That is, main counter
 760  * ticks expired before interrupts are enabled.
 761  */
 762 #define TICK_CALIBRATE  (1000UL)
 763
 764 static unsigned long hpet_calibrate(struct hpets *hpetp)
 765 {
 766         struct hpet_timer __iomem *timer = NULL;
 767         unsigned long t, m, count, i, flags, start;
 768         struct hpet_dev *devp;
 769         int j;
 770         struct hpet __iomem *hpet;
 771
 772         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 773                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 774                         timer = devp->hd_timer;
 775                         break;
 776                 }
 777
 778         if (!timer)
 779                 return 0;
 780
 781         hpet = hpetp->hp_hpet;
 782         t = read_counter(&timer->hpet_compare);
 783
 784         i = 0;
 785         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 786
 787         local_irq_save(flags);
 788
 789         start = read_counter(&hpet->hpet_mc);
 790
 791         do {
 792                 m = read_counter(&hpet->hpet_mc);
 793                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 794         } while (i++, (m - start) < count);
 795
 796         local_irq_restore(flags);
 797
 798         return (m - start) / i;
 799 }
 800
 801 int hpet_alloc(struct hpet_data *hdp)
 802 {
 803         u64 cap, mcfg;
 804         struct hpet_dev *devp;
 805         u32 i, ntimer;
 806         struct hpets *hpetp;
 807         size_t siz;
 808         struct hpet __iomem *hpet;
 809         static struct hpets *last = NULL;
 810         unsigned long period;
 811         unsigned long long temp;
 812
 813         /*
 814          * hpet_alloc can be called by platform dependent code.
 815          * If platform dependent code has allocated the hpet that
 816          * ACPI has also reported, then we catch it here.
 817          */
 818         if (hpet_is_known(hdp)) {
 819                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 820                         __func__);
 821                 return 0;
 822         }
 823
 824         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 825                                       sizeof(struct hpet_dev));
 826
 827         hpetp = kzalloc(siz, GFP_KERNEL);
 828
 829         if (!hpetp)
 830                 return -ENOMEM;
 831
 832         hpetp->hp_which = hpet_nhpet++;
 833         hpetp->hp_hpet = hdp->hd_address;
 834         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 835
 836         hpetp->hp_ntimer = hdp->hd_nirqs;
 837
 838         for (i = 0; i < hdp->hd_nirqs; i++)
 839                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 840
 841         hpet = hpetp->hp_hpet;
 842
 843         cap = readq(&hpet->hpet_cap);
 844
 845         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 846
 847         if (hpetp->hp_ntimer != ntimer) {
 848                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 849                        " with number of timers\n");
 850                 kfree(hpetp);
 851                 return -ENODEV;
 852         }
 853
 854         if (last)
 855                 last->hp_next = hpetp;
 856         else
 857                 hpets = hpetp;
 858
 859         last = hpetp;
 860
 861         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 862                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 863         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 864         temp += period >> 1; /* round */
 865         do_div(temp, period);
 866         hpetp->hp_tick_freq = temp; /* ticks per second */
 867
 868         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 869                 hpetp->hp_which, hdp->hd_phys_address,
 870                 hpetp->hp_ntimer > 1 ? "s" : "");
 871         for (i = 0; i < hpetp->hp_ntimer; i++)
 872                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 873         printk("\n");
 874
 875         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
 876                hpetp->hp_which, hpetp->hp_ntimer,
 877                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
 878
 879         mcfg = readq(&hpet->hpet_config);
 880         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 881                 write_counter(0L, &hpet->hpet_mc);
 882                 mcfg |= HPET_ENABLE_CNF_MASK;
 883                 writeq(mcfg, &hpet->hpet_config);
 884         }
 885
 886         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 887                 struct hpet_timer __iomem *timer;
 888
 889                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 890
 891                 devp->hd_hpets = hpetp;
 892                 devp->hd_hpet = hpet;
 893                 devp->hd_timer = timer;
 894
 895                 /*
 896                  * If the timer was reserved by platform code,
 897                  * then make timer unavailable for opens.
 898                  */
 899                 if (hdp->hd_state & (1 << i)) {
 900                         devp->hd_flags = HPET_OPEN;
 901                         continue;
 902                 }
 903
 904                 init_waitqueue_head(&devp->hd_waitqueue);
 905         }
 906
 907         hpetp->hp_delta = hpet_calibrate(hpetp);
 908
 909 /* This clocksource driver currently only works on ia64 */
 910 #ifdef CONFIG_IA64
 911         if (!hpet_clocksource) {
 912                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
 913                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
 914                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
 915                                                 clocksource_hpet.shift);
 916                 clocksource_register(&clocksource_hpet);
 917                 hpetp->hp_clocksource = &clocksource_hpet;
 918                 hpet_clocksource = &clocksource_hpet;
 919         }
 920 #endif
 921
 922         return 0;
 923 }
 924
 925 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 926 {
 927         struct hpet_data *hdp;
 928         acpi_status status;
 929         struct acpi_resource_address64 addr;
 930
 931         hdp = data;
 932
 933         status = acpi_resource_to_address64(res, &addr);
 934
 935         if (ACPI_SUCCESS(status)) {
 936                 hdp->hd_phys_address = addr.minimum;
 937                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 938
 939                 if (hpet_is_known(hdp)) {
 940                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 941                                 __func__, hdp->hd_phys_address);
 942                         iounmap(hdp->hd_address);
 943                         return AE_ALREADY_EXISTS;
 944                 }
 945         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 946                 struct acpi_resource_fixed_memory32 *fixmem32;
 947
 948                 fixmem32 = &res->data.fixed_memory32;
 949                 if (!fixmem32)
 950                         return AE_NO_MEMORY;
 951
 952                 hdp->hd_phys_address = fixmem32->address;
 953                 hdp->hd_address = ioremap(fixmem32->address,
 954                                                 HPET_RANGE_SIZE);
 955
 956                 if (hpet_is_known(hdp)) {
 957                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 958                                 __func__, hdp->hd_phys_address);
 959                         iounmap(hdp->hd_address);
 960                         return AE_ALREADY_EXISTS;
 961                 }
 962         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 963                 struct acpi_resource_extended_irq *irqp;
 964                 int i, irq;
 965
 966                 irqp = &res->data.extended_irq;
 967
 968                 for (i = 0; i < irqp->interrupt_count; i++) {
 969                         irq = acpi_register_gsi(irqp->interrupts[i],
 970                                       irqp->triggering, irqp->polarity);
 971                         if (irq < 0)
 972                                 return AE_ERROR;
 973
 974                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 975                         hdp->hd_nirqs++;
 976                 }
 977         }
 978
 979         return AE_OK;
 980 }
 981
 982 static int hpet_acpi_add(struct acpi_device *device)
 983 {
 984         acpi_status result;
 985         struct hpet_data data;
 986
 987         memset(&data, 0, sizeof(data));
 988
 989         result =
 990             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 991                                 hpet_resources, &data);
 992
 993         if (ACPI_FAILURE(result))
 994                 return -ENODEV;
 995
 996         if (!data.hd_address || !data.hd_nirqs) {
 997                 printk("%s: no address or irqs in _CRS\n", __func__);
 998                 return -ENODEV;
 999         }
1000
1001         return hpet_alloc(&data);
1002 }
1003
1004 static int hpet_acpi_remove(struct acpi_device *device, int type)
1005 {
1006         /* XXX need to unregister clocksource, dealloc mem, etc */
1007         return -EINVAL;
1008 }
1009
1010 static const struct acpi_device_id hpet_device_ids[] = {
1011         {"PNP0103", 0},
1012         {"", 0},
1013 };
1014 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1015
1016 static struct acpi_driver hpet_acpi_driver = {
1017         .name = "hpet",
1018         .ids = hpet_device_ids,
1019         .ops = {
1020                 .add = hpet_acpi_add,
1021                 .remove = hpet_acpi_remove,
1022                 },
1023 };
1024
1025 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1026
1027 static int __init hpet_init(void)
1028 {
1029         int result;
1030
1031         result = misc_register(&hpet_misc);
1032         if (result < 0)
1033                 return -ENODEV;
1034
1035         sysctl_header = register_sysctl_table(dev_root);
1036
1037         result = acpi_bus_register_driver(&hpet_acpi_driver);
1038         if (result < 0) {
1039                 if (sysctl_header)
1040                         unregister_sysctl_table(sysctl_header);
1041                 misc_deregister(&hpet_misc);
1042                 return result;
1043         }
1044
1045         return 0;
1046 }
1047
1048 static void __exit hpet_exit(void)
1049 {
1050         acpi_bus_unregister_driver(&hpet_acpi_driver);
1051
1052         if (sysctl_header)
1053                 unregister_sysctl_table(sysctl_header);
1054         misc_deregister(&hpet_misc);
1055
1056         return;
1057 }
1058
1059 module_init(hpet_init);
1060 module_exit(hpet_exit);
1061 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1062 MODULE_LICENSE("GPL");