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/mm.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 #include <linux/compat.h>
  33 #include <linux/clocksource.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/slab.h>
  36 #include <linux/io.h>
  37
  38 #include <asm/current.h>
  39 #include <asm/system.h>
  40 #include <asm/irq.h>
  41 #include <asm/div64.h>
  42
  43 #include <linux/acpi.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <linux/hpet.h>
  46
  47 /*
  48  * The High Precision Event Timer driver.
  49  * This driver is closely modelled after the rtc.c driver.
  50  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
  51  */
  52 #define HPET_USER_FREQ  (64)
  53 #define HPET_DRIFT      (500)
  54
  55 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  56
  57
  58 /* WARNING -- don't get confused.  These macros are never used
  59  * to write the (single) counter, and rarely to read it.
  60  * They're badly named; to fix, someday.
  61  */
  62 #if BITS_PER_LONG == 64
  63 #define write_counter(V, MC)    writeq(V, MC)
  64 #define read_counter(MC)        readq(MC)
  65 #else
  66 #define write_counter(V, MC)    writel(V, MC)
  67 #define read_counter(MC)        readl(MC)
  68 #endif
  69
  70 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
  71 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  72
  73 /* This clocksource driver currently only works on ia64 */
  74 #ifdef CONFIG_IA64
  75 static void __iomem *hpet_mctr;
  76
  77 static cycle_t read_hpet(struct clocksource *cs)
  78 {
  79         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
  80 }
  81
  82 static struct clocksource clocksource_hpet = {
  83         .name           = "hpet",
  84         .rating         = 250,
  85         .read           = read_hpet,
  86         .mask           = CLOCKSOURCE_MASK(64),
  87         .mult           = 0,            /* to be calculated */
  88         .shift          = 10,
  89         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  90 };
  91 static struct clocksource *hpet_clocksource;
  92 #endif
  93
  94 /* A lock for concurrent access by app and isr hpet activity. */
  95 static DEFINE_SPINLOCK(hpet_lock);
  96
  97 #define HPET_DEV_NAME   (7)
  98
  99 struct hpet_dev {
 100         struct hpets *hd_hpets;
 101         struct hpet __iomem *hd_hpet;
 102         struct hpet_timer __iomem *hd_timer;
 103         unsigned long hd_ireqfreq;
 104         unsigned long hd_irqdata;
 105         wait_queue_head_t hd_waitqueue;
 106         struct fasync_struct *hd_async_queue;
 107         unsigned int hd_flags;
 108         unsigned int hd_irq;
 109         unsigned int hd_hdwirq;
 110         char hd_name[HPET_DEV_NAME];
 111 };
 112
 113 struct hpets {
 114         struct hpets *hp_next;
 115         struct hpet __iomem *hp_hpet;
 116         unsigned long hp_hpet_phys;
 117         struct clocksource *hp_clocksource;
 118         unsigned long long hp_tick_freq;
 119         unsigned long hp_delta;
 120         unsigned int hp_ntimer;
 121         unsigned int hp_which;
 122         struct hpet_dev hp_dev[1];
 123 };
 124
 125 static struct hpets *hpets;
 126
 127 #define HPET_OPEN               0x0001
 128 #define HPET_IE                 0x0002  /* interrupt enabled */
 129 #define HPET_PERIODIC           0x0004
 130 #define HPET_SHARED_IRQ         0x0008
 131
 132
 133 #ifndef readq
 134 static inline unsigned long long readq(void __iomem *addr)
 135 {
 136         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 137 }
 138 #endif
 139
 140 #ifndef writeq
 141 static inline void writeq(unsigned long long v, void __iomem *addr)
 142 {
 143         writel(v & 0xffffffff, addr);
 144         writel(v >> 32, addr + 4);
 145 }
 146 #endif
 147
 148 static irqreturn_t hpet_interrupt(int irq, void *data)
 149 {
 150         struct hpet_dev *devp;
 151         unsigned long isr;
 152
 153         devp = data;
 154         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 155
 156         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 157             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 158                 return IRQ_NONE;
 159
 160         spin_lock(&hpet_lock);
 161         devp->hd_irqdata++;
 162
 163         /*
 164          * For non-periodic timers, increment the accumulator.
 165          * This has the effect of treating non-periodic like periodic.
 166          */
 167         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 168                 unsigned long m, t;
 169
 170                 t = devp->hd_ireqfreq;
 171                 m = read_counter(&devp->hd_timer->hpet_compare);
 172                 write_counter(t + m, &devp->hd_timer->hpet_compare);
 173         }
 174
 175         if (devp->hd_flags & HPET_SHARED_IRQ)
 176                 writel(isr, &devp->hd_hpet->hpet_isr);
 177         spin_unlock(&hpet_lock);
 178
 179         wake_up_interruptible(&devp->hd_waitqueue);
 180
 181         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 182
 183         return IRQ_HANDLED;
 184 }
 185
 186 static void hpet_timer_set_irq(struct hpet_dev *devp)
 187 {
 188         unsigned long v;
 189         int irq, gsi;
 190         struct hpet_timer __iomem *timer;
 191
 192         spin_lock_irq(&hpet_lock);
 193         if (devp->hd_hdwirq) {
 194                 spin_unlock_irq(&hpet_lock);
 195                 return;
 196         }
 197
 198         timer = devp->hd_timer;
 199
 200         /* we prefer level triggered mode */
 201         v = readl(&timer->hpet_config);
 202         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
 203                 v |= Tn_INT_TYPE_CNF_MASK;
 204                 writel(v, &timer->hpet_config);
 205         }
 206         spin_unlock_irq(&hpet_lock);
 207
 208         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
 209                                  Tn_INT_ROUTE_CAP_SHIFT;
 210
 211         /*
 212          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
 213          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
 214          */
 215         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 216                 v &= ~0xf3df;
 217         else
 218                 v &= ~0xffff;
 219
 220         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
 221                 if (irq >= nr_irqs) {
 222                         irq = HPET_MAX_IRQ;
 223                         break;
 224                 }
 225
 226                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
 227                                         ACPI_ACTIVE_LOW);
 228                 if (gsi > 0)
 229                         break;
 230
 231                 /* FIXME: Setup interrupt source table */
 232         }
 233
 234         if (irq < HPET_MAX_IRQ) {
 235                 spin_lock_irq(&hpet_lock);
 236                 v = readl(&timer->hpet_config);
 237                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
 238                 writel(v, &timer->hpet_config);
 239                 devp->hd_hdwirq = gsi;
 240                 spin_unlock_irq(&hpet_lock);
 241         }
 242         return;
 243 }
 244
 245 static int hpet_open(struct inode *inode, struct file *file)
 246 {
 247         struct hpet_dev *devp;
 248         struct hpets *hpetp;
 249         int i;
 250
 251         if (file->f_mode & FMODE_WRITE)
 252                 return -EINVAL;
 253
 254         mutex_lock(&hpet_mutex);
 255         spin_lock_irq(&hpet_lock);
 256
 257         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 258                 for (i = 0; i < hpetp->hp_ntimer; i++)
 259                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
 260                                 continue;
 261                         else {
 262                                 devp = &hpetp->hp_dev[i];
 263                                 break;
 264                         }
 265
 266         if (!devp) {
 267                 spin_unlock_irq(&hpet_lock);
 268                 mutex_unlock(&hpet_mutex);
 269                 return -EBUSY;
 270         }
 271
 272         file->private_data = devp;
 273         devp->hd_irqdata = 0;
 274         devp->hd_flags |= HPET_OPEN;
 275         spin_unlock_irq(&hpet_lock);
 276         mutex_unlock(&hpet_mutex);
 277
 278         hpet_timer_set_irq(devp);
 279
 280         return 0;
 281 }
 282
 283 static ssize_t
 284 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 285 {
 286         DECLARE_WAITQUEUE(wait, current);
 287         unsigned long data;
 288         ssize_t retval;
 289         struct hpet_dev *devp;
 290
 291         devp = file->private_data;
 292         if (!devp->hd_ireqfreq)
 293                 return -EIO;
 294
 295         if (count < sizeof(unsigned long))
 296                 return -EINVAL;
 297
 298         add_wait_queue(&devp->hd_waitqueue, &wait);
 299
 300         for ( ; ; ) {
 301                 set_current_state(TASK_INTERRUPTIBLE);
 302
 303                 spin_lock_irq(&hpet_lock);
 304                 data = devp->hd_irqdata;
 305                 devp->hd_irqdata = 0;
 306                 spin_unlock_irq(&hpet_lock);
 307
 308                 if (data)
 309                         break;
 310                 else if (file->f_flags & O_NONBLOCK) {
 311                         retval = -EAGAIN;
 312                         goto out;
 313                 } else if (signal_pending(current)) {
 314                         retval = -ERESTARTSYS;
 315                         goto out;
 316                 }
 317                 schedule();
 318         }
 319
 320         retval = put_user(data, (unsigned long __user *)buf);
 321         if (!retval)
 322                 retval = sizeof(unsigned long);
 323 out:
 324         __set_current_state(TASK_RUNNING);
 325         remove_wait_queue(&devp->hd_waitqueue, &wait);
 326
 327         return retval;
 328 }
 329
 330 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 331 {
 332         unsigned long v;
 333         struct hpet_dev *devp;
 334
 335         devp = file->private_data;
 336
 337         if (!devp->hd_ireqfreq)
 338                 return 0;
 339
 340         poll_wait(file, &devp->hd_waitqueue, wait);
 341
 342         spin_lock_irq(&hpet_lock);
 343         v = devp->hd_irqdata;
 344         spin_unlock_irq(&hpet_lock);
 345
 346         if (v != 0)
 347                 return POLLIN | POLLRDNORM;
 348
 349         return 0;
 350 }
 351
 352 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 353 {
 354 #ifdef  CONFIG_HPET_MMAP
 355         struct hpet_dev *devp;
 356         unsigned long addr;
 357
 358         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 359                 return -EINVAL;
 360
 361         devp = file->private_data;
 362         addr = devp->hd_hpets->hp_hpet_phys;
 363
 364         if (addr & (PAGE_SIZE - 1))
 365                 return -ENOSYS;
 366
 367         vma->vm_flags |= VM_IO;
 368         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 369
 370         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 371                                         PAGE_SIZE, vma->vm_page_prot)) {
 372                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
 373                         __func__);
 374                 return -EAGAIN;
 375         }
 376
 377         return 0;
 378 #else
 379         return -ENOSYS;
 380 #endif
 381 }
 382
 383 static int hpet_fasync(int fd, struct file *file, int on)
 384 {
 385         struct hpet_dev *devp;
 386
 387         devp = file->private_data;
 388
 389         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 390                 return 0;
 391         else
 392                 return -EIO;
 393 }
 394
 395 static int hpet_release(struct inode *inode, struct file *file)
 396 {
 397         struct hpet_dev *devp;
 398         struct hpet_timer __iomem *timer;
 399         int irq = 0;
 400
 401         devp = file->private_data;
 402         timer = devp->hd_timer;
 403
 404         spin_lock_irq(&hpet_lock);
 405
 406         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 407                &timer->hpet_config);
 408
 409         irq = devp->hd_irq;
 410         devp->hd_irq = 0;
 411
 412         devp->hd_ireqfreq = 0;
 413
 414         if (devp->hd_flags & HPET_PERIODIC
 415             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 416                 unsigned long v;
 417
 418                 v = readq(&timer->hpet_config);
 419                 v ^= Tn_TYPE_CNF_MASK;
 420                 writeq(v, &timer->hpet_config);
 421         }
 422
 423         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 424         spin_unlock_irq(&hpet_lock);
 425
 426         if (irq)
 427                 free_irq(irq, devp);
 428
 429         file->private_data = NULL;
 430         return 0;
 431 }
 432
 433 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 434 {
 435         struct hpet_timer __iomem *timer;
 436         struct hpet __iomem *hpet;
 437         struct hpets *hpetp;
 438         int irq;
 439         unsigned long g, v, t, m;
 440         unsigned long flags, isr;
 441
 442         timer = devp->hd_timer;
 443         hpet = devp->hd_hpet;
 444         hpetp = devp->hd_hpets;
 445
 446         if (!devp->hd_ireqfreq)
 447                 return -EIO;
 448
 449         spin_lock_irq(&hpet_lock);
 450
 451         if (devp->hd_flags & HPET_IE) {
 452                 spin_unlock_irq(&hpet_lock);
 453                 return -EBUSY;
 454         }
 455
 456         devp->hd_flags |= HPET_IE;
 457
 458         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 459                 devp->hd_flags |= HPET_SHARED_IRQ;
 460         spin_unlock_irq(&hpet_lock);
 461
 462         irq = devp->hd_hdwirq;
 463
 464         if (irq) {
 465                 unsigned long irq_flags;
 466
 467                 if (devp->hd_flags & HPET_SHARED_IRQ) {
 468                         /*
 469                          * To prevent the interrupt handler from seeing an
 470                          * unwanted interrupt status bit, program the timer
 471                          * so that it will not fire in the near future ...
 472                          */
 473                         writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
 474                                &timer->hpet_config);
 475                         write_counter(read_counter(&hpet->hpet_mc),
 476                                       &timer->hpet_compare);
 477                         /* ... and clear any left-over status. */
 478                         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 479                         writel(isr, &hpet->hpet_isr);
 480                 }
 481
 482                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 483                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 484                                                 ? IRQF_SHARED : IRQF_DISABLED;
 485                 if (request_irq(irq, hpet_interrupt, irq_flags,
 486                                 devp->hd_name, (void *)devp)) {
 487                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 488                         irq = 0;
 489                 }
 490         }
 491
 492         if (irq == 0) {
 493                 spin_lock_irq(&hpet_lock);
 494                 devp->hd_flags ^= HPET_IE;
 495                 spin_unlock_irq(&hpet_lock);
 496                 return -EIO;
 497         }
 498
 499         devp->hd_irq = irq;
 500         t = devp->hd_ireqfreq;
 501         v = readq(&timer->hpet_config);
 502
 503         /* 64-bit comparators are not yet supported through the ioctls,
 504          * so force this into 32-bit mode if it supports both modes
 505          */
 506         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
 507
 508         if (devp->hd_flags & HPET_PERIODIC) {
 509                 g |= Tn_TYPE_CNF_MASK;
 510                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
 511                 writeq(v, &timer->hpet_config);
 512                 local_irq_save(flags);
 513
 514                 /*
 515                  * NOTE: First we modify the hidden accumulator
 516                  * register supported by periodic-capable comparators.
 517                  * We never want to modify the (single) counter; that
 518                  * would affect all the comparators. The value written
 519                  * is the counter value when the first interrupt is due.
 520                  */
 521                 m = read_counter(&hpet->hpet_mc);
 522                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 523                 /*
 524                  * Then we modify the comparator, indicating the period
 525                  * for subsequent interrupt.
 526                  */
 527                 write_counter(t, &timer->hpet_compare);
 528         } else {
 529                 local_irq_save(flags);
 530                 m = read_counter(&hpet->hpet_mc);
 531                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 532         }
 533
 534         if (devp->hd_flags & HPET_SHARED_IRQ) {
 535                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 536                 writel(isr, &hpet->hpet_isr);
 537         }
 538         writeq(g, &timer->hpet_config);
 539         local_irq_restore(flags);
 540
 541         return 0;
 542 }
 543
 544 /* converts Hz to number of timer ticks */
 545 static inline unsigned long hpet_time_div(struct hpets *hpets,
 546                                           unsigned long dis)
 547 {
 548         unsigned long long m;
 549
 550         m = hpets->hp_tick_freq + (dis >> 1);
 551         do_div(m, dis);
 552         return (unsigned long)m;
 553 }
 554
 555 static int
 556 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
 557                   struct hpet_info *info)
 558 {
 559         struct hpet_timer __iomem *timer;
 560         struct hpet __iomem *hpet;
 561         struct hpets *hpetp;
 562         int err;
 563         unsigned long v;
 564
 565         switch (cmd) {
 566         case HPET_IE_OFF:
 567         case HPET_INFO:
 568         case HPET_EPI:
 569         case HPET_DPI:
 570         case HPET_IRQFREQ:
 571                 timer = devp->hd_timer;
 572                 hpet = devp->hd_hpet;
 573                 hpetp = devp->hd_hpets;
 574                 break;
 575         case HPET_IE_ON:
 576                 return hpet_ioctl_ieon(devp);
 577         default:
 578                 return -EINVAL;
 579         }
 580
 581         err = 0;
 582
 583         switch (cmd) {
 584         case HPET_IE_OFF:
 585                 if ((devp->hd_flags & HPET_IE) == 0)
 586                         break;
 587                 v = readq(&timer->hpet_config);
 588                 v &= ~Tn_INT_ENB_CNF_MASK;
 589                 writeq(v, &timer->hpet_config);
 590                 if (devp->hd_irq) {
 591                         free_irq(devp->hd_irq, devp);
 592                         devp->hd_irq = 0;
 593                 }
 594                 devp->hd_flags ^= HPET_IE;
 595                 break;
 596         case HPET_INFO:
 597                 {
 598                         memset(info, 0, sizeof(*info));
 599                         if (devp->hd_ireqfreq)
 600                                 info->hi_ireqfreq =
 601                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 602                         info->hi_flags =
 603                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 604                         info->hi_hpet = hpetp->hp_which;
 605                         info->hi_timer = devp - hpetp->hp_dev;
 606                         break;
 607                 }
 608         case HPET_EPI:
 609                 v = readq(&timer->hpet_config);
 610                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 611                         err = -ENXIO;
 612                         break;
 613                 }
 614                 devp->hd_flags |= HPET_PERIODIC;
 615                 break;
 616         case HPET_DPI:
 617                 v = readq(&timer->hpet_config);
 618                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 619                         err = -ENXIO;
 620                         break;
 621                 }
 622                 if (devp->hd_flags & HPET_PERIODIC &&
 623                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 624                         v = readq(&timer->hpet_config);
 625                         v ^= Tn_TYPE_CNF_MASK;
 626                         writeq(v, &timer->hpet_config);
 627                 }
 628                 devp->hd_flags &= ~HPET_PERIODIC;
 629                 break;
 630         case HPET_IRQFREQ:
 631                 if ((arg > hpet_max_freq) &&
 632                     !capable(CAP_SYS_RESOURCE)) {
 633                         err = -EACCES;
 634                         break;
 635                 }
 636
 637                 if (!arg) {
 638                         err = -EINVAL;
 639                         break;
 640                 }
 641
 642                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 643         }
 644
 645         return err;
 646 }
 647
 648 static long
 649 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 650 {
 651         struct hpet_info info;
 652         int err;
 653
 654         mutex_lock(&hpet_mutex);
 655         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
 656         mutex_unlock(&hpet_mutex);
 657
 658         if ((cmd == HPET_INFO) && !err &&
 659             (copy_to_user((void __user *)arg, &info, sizeof(info))))
 660                 err = -EFAULT;
 661
 662         return err;
 663 }
 664
 665 #ifdef CONFIG_COMPAT
 666 struct compat_hpet_info {
 667         compat_ulong_t hi_ireqfreq;     /* Hz */
 668         compat_ulong_t hi_flags;        /* information */
 669         unsigned short hi_hpet;
 670         unsigned short hi_timer;
 671 };
 672
 673 static long
 674 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 675 {
 676         struct hpet_info info;
 677         int err;
 678
 679         mutex_lock(&hpet_mutex);
 680         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
 681         mutex_unlock(&hpet_mutex);
 682
 683         if ((cmd == HPET_INFO) && !err) {
 684                 struct compat_hpet_info __user *u = compat_ptr(arg);
 685                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
 686                     put_user(info.hi_flags, &u->hi_flags) ||
 687                     put_user(info.hi_hpet, &u->hi_hpet) ||
 688                     put_user(info.hi_timer, &u->hi_timer))
 689                         err = -EFAULT;
 690         }
 691
 692         return err;
 693 }
 694 #endif
 695
 696 static const struct file_operations hpet_fops = {
 697         .owner = THIS_MODULE,
 698         .llseek = no_llseek,
 699         .read = hpet_read,
 700         .poll = hpet_poll,
 701         .unlocked_ioctl = hpet_ioctl,
 702 #ifdef CONFIG_COMPAT
 703         .compat_ioctl = hpet_compat_ioctl,
 704 #endif
 705         .open = hpet_open,
 706         .release = hpet_release,
 707         .fasync = hpet_fasync,
 708         .mmap = hpet_mmap,
 709 };
 710
 711 static int hpet_is_known(struct hpet_data *hdp)
 712 {
 713         struct hpets *hpetp;
 714
 715         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 716                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 717                         return 1;
 718
 719         return 0;
 720 }
 721
 722 static ctl_table hpet_table[] = {
 723         {
 724          .procname = "max-user-freq",
 725          .data = &hpet_max_freq,
 726          .maxlen = sizeof(int),
 727          .mode = 0644,
 728          .proc_handler = proc_dointvec,
 729          },
 730         {}
 731 };
 732
 733 static ctl_table hpet_root[] = {
 734         {
 735          .procname = "hpet",
 736          .maxlen = 0,
 737          .mode = 0555,
 738          .child = hpet_table,
 739          },
 740         {}
 741 };
 742
 743 static ctl_table dev_root[] = {
 744         {
 745          .procname = "dev",
 746          .maxlen = 0,
 747          .mode = 0555,
 748          .child = hpet_root,
 749          },
 750         {}
 751 };
 752
 753 static struct ctl_table_header *sysctl_header;
 754
 755 /*
 756  * Adjustment for when arming the timer with
 757  * initial conditions.  That is, main counter
 758  * ticks expired before interrupts are enabled.
 759  */
 760 #define TICK_CALIBRATE  (1000UL)
 761
 762 static unsigned long __hpet_calibrate(struct hpets *hpetp)
 763 {
 764         struct hpet_timer __iomem *timer = NULL;
 765         unsigned long t, m, count, i, flags, start;
 766         struct hpet_dev *devp;
 767         int j;
 768         struct hpet __iomem *hpet;
 769
 770         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 771                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 772                         timer = devp->hd_timer;
 773                         break;
 774                 }
 775
 776         if (!timer)
 777                 return 0;
 778
 779         hpet = hpetp->hp_hpet;
 780         t = read_counter(&timer->hpet_compare);
 781
 782         i = 0;
 783         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 784
 785         local_irq_save(flags);
 786
 787         start = read_counter(&hpet->hpet_mc);
 788
 789         do {
 790                 m = read_counter(&hpet->hpet_mc);
 791                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 792         } while (i++, (m - start) < count);
 793
 794         local_irq_restore(flags);
 795
 796         return (m - start) / i;
 797 }
 798
 799 static unsigned long hpet_calibrate(struct hpets *hpetp)
 800 {
 801         unsigned long ret = -1;
 802         unsigned long tmp;
 803
 804         /*
 805          * Try to calibrate until return value becomes stable small value.
 806          * If SMI interruption occurs in calibration loop, the return value
 807          * will be big. This avoids its impact.
 808          */
 809         for ( ; ; ) {
 810                 tmp = __hpet_calibrate(hpetp);
 811                 if (ret <= tmp)
 812                         break;
 813                 ret = tmp;
 814         }
 815
 816         return ret;
 817 }
 818
 819 int hpet_alloc(struct hpet_data *hdp)
 820 {
 821         u64 cap, mcfg;
 822         struct hpet_dev *devp;
 823         u32 i, ntimer;
 824         struct hpets *hpetp;
 825         size_t siz;
 826         struct hpet __iomem *hpet;
 827         static struct hpets *last;
 828         unsigned long period;
 829         unsigned long long temp;
 830         u32 remainder;
 831
 832         /*
 833          * hpet_alloc can be called by platform dependent code.
 834          * If platform dependent code has allocated the hpet that
 835          * ACPI has also reported, then we catch it here.
 836          */
 837         if (hpet_is_known(hdp)) {
 838                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 839                         __func__);
 840                 return 0;
 841         }
 842
 843         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 844                                       sizeof(struct hpet_dev));
 845
 846         hpetp = kzalloc(siz, GFP_KERNEL);
 847
 848         if (!hpetp)
 849                 return -ENOMEM;
 850
 851         hpetp->hp_which = hpet_nhpet++;
 852         hpetp->hp_hpet = hdp->hd_address;
 853         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 854
 855         hpetp->hp_ntimer = hdp->hd_nirqs;
 856
 857         for (i = 0; i < hdp->hd_nirqs; i++)
 858                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 859
 860         hpet = hpetp->hp_hpet;
 861
 862         cap = readq(&hpet->hpet_cap);
 863
 864         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 865
 866         if (hpetp->hp_ntimer != ntimer) {
 867                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 868                        " with number of timers\n");
 869                 kfree(hpetp);
 870                 return -ENODEV;
 871         }
 872
 873         if (last)
 874                 last->hp_next = hpetp;
 875         else
 876                 hpets = hpetp;
 877
 878         last = hpetp;
 879
 880         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 881                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 882         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 883         temp += period >> 1; /* round */
 884         do_div(temp, period);
 885         hpetp->hp_tick_freq = temp; /* ticks per second */
 886
 887         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 888                 hpetp->hp_which, hdp->hd_phys_address,
 889                 hpetp->hp_ntimer > 1 ? "s" : "");
 890         for (i = 0; i < hpetp->hp_ntimer; i++)
 891                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 892         printk("\n");
 893
 894         temp = hpetp->hp_tick_freq;
 895         remainder = do_div(temp, 1000000);
 896         printk(KERN_INFO
 897                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
 898                 hpetp->hp_which, hpetp->hp_ntimer,
 899                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
 900                 (unsigned) temp, remainder);
 901
 902         mcfg = readq(&hpet->hpet_config);
 903         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 904                 write_counter(0L, &hpet->hpet_mc);
 905                 mcfg |= HPET_ENABLE_CNF_MASK;
 906                 writeq(mcfg, &hpet->hpet_config);
 907         }
 908
 909         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 910                 struct hpet_timer __iomem *timer;
 911
 912                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 913
 914                 devp->hd_hpets = hpetp;
 915                 devp->hd_hpet = hpet;
 916                 devp->hd_timer = timer;
 917
 918                 /*
 919                  * If the timer was reserved by platform code,
 920                  * then make timer unavailable for opens.
 921                  */
 922                 if (hdp->hd_state & (1 << i)) {
 923                         devp->hd_flags = HPET_OPEN;
 924                         continue;
 925                 }
 926
 927                 init_waitqueue_head(&devp->hd_waitqueue);
 928         }
 929
 930         hpetp->hp_delta = hpet_calibrate(hpetp);
 931
 932 /* This clocksource driver currently only works on ia64 */
 933 #ifdef CONFIG_IA64
 934         if (!hpet_clocksource) {
 935                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
 936                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
 937                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
 938                                                 clocksource_hpet.shift);
 939                 clocksource_register(&clocksource_hpet);
 940                 hpetp->hp_clocksource = &clocksource_hpet;
 941                 hpet_clocksource = &clocksource_hpet;
 942         }
 943 #endif
 944
 945         return 0;
 946 }
 947
 948 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 949 {
 950         struct hpet_data *hdp;
 951         acpi_status status;
 952         struct acpi_resource_address64 addr;
 953
 954         hdp = data;
 955
 956         status = acpi_resource_to_address64(res, &addr);
 957
 958         if (ACPI_SUCCESS(status)) {
 959                 hdp->hd_phys_address = addr.minimum;
 960                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 961
 962                 if (hpet_is_known(hdp)) {
 963                         iounmap(hdp->hd_address);
 964                         return AE_ALREADY_EXISTS;
 965                 }
 966         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 967                 struct acpi_resource_fixed_memory32 *fixmem32;
 968
 969                 fixmem32 = &res->data.fixed_memory32;
 970                 if (!fixmem32)
 971                         return AE_NO_MEMORY;
 972
 973                 hdp->hd_phys_address = fixmem32->address;
 974                 hdp->hd_address = ioremap(fixmem32->address,
 975                                                 HPET_RANGE_SIZE);
 976
 977                 if (hpet_is_known(hdp)) {
 978                         iounmap(hdp->hd_address);
 979                         return AE_ALREADY_EXISTS;
 980                 }
 981         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 982                 struct acpi_resource_extended_irq *irqp;
 983                 int i, irq;
 984
 985                 irqp = &res->data.extended_irq;
 986
 987                 for (i = 0; i < irqp->interrupt_count; i++) {
 988                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
 989                                       irqp->triggering, irqp->polarity);
 990                         if (irq < 0)
 991                                 return AE_ERROR;
 992
 993                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 994                         hdp->hd_nirqs++;
 995                 }
 996         }
 997
 998         return AE_OK;
 999 }
1000
1001 static int hpet_acpi_add(struct acpi_device *device)
1002 {
1003         acpi_status result;
1004         struct hpet_data data;
1005
1006         memset(&data, 0, sizeof(data));
1007
1008         result =
1009             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1010                                 hpet_resources, &data);
1011
1012         if (ACPI_FAILURE(result))
1013                 return -ENODEV;
1014
1015         if (!data.hd_address || !data.hd_nirqs) {
1016                 if (data.hd_address)
1017                         iounmap(data.hd_address);
1018                 printk("%s: no address or irqs in _CRS\n", __func__);
1019                 return -ENODEV;
1020         }
1021
1022         return hpet_alloc(&data);
1023 }
1024
1025 static int hpet_acpi_remove(struct acpi_device *device, int type)
1026 {
1027         /* XXX need to unregister clocksource, dealloc mem, etc */
1028         return -EINVAL;
1029 }
1030
1031 static const struct acpi_device_id hpet_device_ids[] = {
1032         {"PNP0103", 0},
1033         {"", 0},
1034 };
1035 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1036
1037 static struct acpi_driver hpet_acpi_driver = {
1038         .name = "hpet",
1039         .ids = hpet_device_ids,
1040         .ops = {
1041                 .add = hpet_acpi_add,
1042                 .remove = hpet_acpi_remove,
1043                 },
1044 };
1045
1046 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1047
1048 static int __init hpet_init(void)
1049 {
1050         int result;
1051
1052         result = misc_register(&hpet_misc);
1053         if (result < 0)
1054                 return -ENODEV;
1055
1056         sysctl_header = register_sysctl_table(dev_root);
1057
1058         result = acpi_bus_register_driver(&hpet_acpi_driver);
1059         if (result < 0) {
1060                 if (sysctl_header)
1061                         unregister_sysctl_table(sysctl_header);
1062                 misc_deregister(&hpet_misc);
1063                 return result;
1064         }
1065
1066         return 0;
1067 }
1068
1069 static void __exit hpet_exit(void)
1070 {
1071         acpi_bus_unregister_driver(&hpet_acpi_driver);
1072
1073         if (sysctl_header)
1074                 unregister_sysctl_table(sysctl_header);
1075         misc_deregister(&hpet_misc);
1076
1077         return;
1078 }
1079
1080 module_init(hpet_init);
1081 module_exit(hpet_exit);
1082 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1083 MODULE_LICENSE("GPL");