SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/char/hpet.c

   1 /*
   2  * Intel & MS High Precision Event Timer Implementation.
   3  *
   4  * Copyright (C) 2003 Intel Corporation
   5  *      Venki Pallipadi
   6  * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
   7  *      Bob Picco <robert.picco@hp.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/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 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  53
  54 /* A lock for concurrent access by app and isr hpet activity. */
  55 static DEFINE_SPINLOCK(hpet_lock);
  56 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  57 static DEFINE_SPINLOCK(hpet_task_lock);
  58
  59 #define HPET_DEV_NAME   (7)
  60
  61 struct hpet_dev {
  62         struct hpets *hd_hpets;
  63         struct hpet __iomem *hd_hpet;
  64         struct hpet_timer __iomem *hd_timer;
  65         unsigned long hd_ireqfreq;
  66         unsigned long hd_irqdata;
  67         wait_queue_head_t hd_waitqueue;
  68         struct fasync_struct *hd_async_queue;
  69         struct hpet_task *hd_task;
  70         unsigned int hd_flags;
  71         unsigned int hd_irq;
  72         unsigned int hd_hdwirq;
  73         char hd_name[HPET_DEV_NAME];
  74 };
  75
  76 struct hpets {
  77         struct hpets *hp_next;
  78         struct hpet __iomem *hp_hpet;
  79         unsigned long hp_hpet_phys;
  80         struct time_interpolator *hp_interpolator;
  81         unsigned long long hp_tick_freq;
  82         unsigned long hp_delta;
  83         unsigned int hp_ntimer;
  84         unsigned int hp_which;
  85         struct hpet_dev hp_dev[1];
  86 };
  87
  88 static struct hpets *hpets;
  89
  90 #define HPET_OPEN               0x0001
  91 #define HPET_IE                 0x0002  /* interrupt enabled */
  92 #define HPET_PERIODIC           0x0004
  93
  94 #if BITS_PER_LONG == 64
  95 #define write_counter(V, MC)    writeq(V, MC)
  96 #define read_counter(MC)        readq(MC)
  97 #else
  98 #define write_counter(V, MC)    writel(V, MC)
  99 #define read_counter(MC)        readl(MC)
 100 #endif
 101
 102 #ifndef readq
 103 static inline unsigned long long readq(void __iomem *addr)
 104 {
 105         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 106 }
 107 #endif
 108
 109 #ifndef writeq
 110 static inline void writeq(unsigned long long v, void __iomem *addr)
 111 {
 112         writel(v & 0xffffffff, addr);
 113         writel(v >> 32, addr + 4);
 114 }
 115 #endif
 116
 117 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
 118 {
 119         struct hpet_dev *devp;
 120         unsigned long isr;
 121
 122         devp = data;
 123
 124         spin_lock(&hpet_lock);
 125         devp->hd_irqdata++;
 126
 127         /*
 128          * For non-periodic timers, increment the accumulator.
 129          * This has the effect of treating non-periodic like periodic.
 130          */
 131         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 132                 unsigned long m, t;
 133
 134                 t = devp->hd_ireqfreq;
 135                 m = read_counter(&devp->hd_hpet->hpet_mc);
 136                 write_counter(t + m + devp->hd_hpets->hp_delta,
 137                               &devp->hd_timer->hpet_compare);
 138         }
 139
 140         isr = (1 << (devp - devp->hd_hpets->hp_dev));
 141         writeq(isr, &devp->hd_hpet->hpet_isr);
 142         spin_unlock(&hpet_lock);
 143
 144         spin_lock(&hpet_task_lock);
 145         if (devp->hd_task)
 146                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 147         spin_unlock(&hpet_task_lock);
 148
 149         wake_up_interruptible(&devp->hd_waitqueue);
 150
 151         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 152
 153         return IRQ_HANDLED;
 154 }
 155
 156 static int hpet_open(struct inode *inode, struct file *file)
 157 {
 158         struct hpet_dev *devp;
 159         struct hpets *hpetp;
 160         int i;
 161
 162         if (file->f_mode & FMODE_WRITE)
 163                 return -EINVAL;
 164
 165         spin_lock_irq(&hpet_lock);
 166
 167         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 168                 for (i = 0; i < hpetp->hp_ntimer; i++)
 169                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 170                             || hpetp->hp_dev[i].hd_task)
 171                                 continue;
 172                         else {
 173                                 devp = &hpetp->hp_dev[i];
 174                                 break;
 175                         }
 176
 177         if (!devp) {
 178                 spin_unlock_irq(&hpet_lock);
 179                 return -EBUSY;
 180         }
 181
 182         file->private_data = devp;
 183         devp->hd_irqdata = 0;
 184         devp->hd_flags |= HPET_OPEN;
 185         spin_unlock_irq(&hpet_lock);
 186
 187         return 0;
 188 }
 189
 190 static ssize_t
 191 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 192 {
 193         DECLARE_WAITQUEUE(wait, current);
 194         unsigned long data;
 195         ssize_t retval;
 196         struct hpet_dev *devp;
 197
 198         devp = file->private_data;
 199         if (!devp->hd_ireqfreq)
 200                 return -EIO;
 201
 202         if (count < sizeof(unsigned long))
 203                 return -EINVAL;
 204
 205         add_wait_queue(&devp->hd_waitqueue, &wait);
 206
 207         for ( ; ; ) {
 208                 set_current_state(TASK_INTERRUPTIBLE);
 209
 210                 spin_lock_irq(&hpet_lock);
 211                 data = devp->hd_irqdata;
 212                 devp->hd_irqdata = 0;
 213                 spin_unlock_irq(&hpet_lock);
 214
 215                 if (data)
 216                         break;
 217                 else if (file->f_flags & O_NONBLOCK) {
 218                         retval = -EAGAIN;
 219                         goto out;
 220                 } else if (signal_pending(current)) {
 221                         retval = -ERESTARTSYS;
 222                         goto out;
 223                 }
 224                 schedule();
 225         }
 226
 227         retval = put_user(data, (unsigned long __user *)buf);
 228         if (!retval)
 229                 retval = sizeof(unsigned long);
 230 out:
 231         __set_current_state(TASK_RUNNING);
 232         remove_wait_queue(&devp->hd_waitqueue, &wait);
 233
 234         return retval;
 235 }
 236
 237 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 238 {
 239         unsigned long v;
 240         struct hpet_dev *devp;
 241
 242         devp = file->private_data;
 243
 244         if (!devp->hd_ireqfreq)
 245                 return 0;
 246
 247         poll_wait(file, &devp->hd_waitqueue, wait);
 248
 249         spin_lock_irq(&hpet_lock);
 250         v = devp->hd_irqdata;
 251         spin_unlock_irq(&hpet_lock);
 252
 253         if (v != 0)
 254                 return POLLIN | POLLRDNORM;
 255
 256         return 0;
 257 }
 258
 259 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 260 {
 261 #ifdef  CONFIG_HPET_MMAP
 262         struct hpet_dev *devp;
 263         unsigned long addr;
 264
 265         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 266                 return -EINVAL;
 267
 268         devp = file->private_data;
 269         addr = devp->hd_hpets->hp_hpet_phys;
 270
 271         if (addr & (PAGE_SIZE - 1))
 272                 return -ENOSYS;
 273
 274         vma->vm_flags |= VM_IO;
 275         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 276
 277         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 278                                         PAGE_SIZE, vma->vm_page_prot)) {
 279                 printk(KERN_ERR "remap_pfn_range failed in hpet.c\n");
 280                 return -EAGAIN;
 281         }
 282
 283         return 0;
 284 #else
 285         return -ENOSYS;
 286 #endif
 287 }
 288
 289 static int hpet_fasync(int fd, struct file *file, int on)
 290 {
 291         struct hpet_dev *devp;
 292
 293         devp = file->private_data;
 294
 295         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 296                 return 0;
 297         else
 298                 return -EIO;
 299 }
 300
 301 static int hpet_release(struct inode *inode, struct file *file)
 302 {
 303         struct hpet_dev *devp;
 304         struct hpet_timer __iomem *timer;
 305         int irq = 0;
 306
 307         devp = file->private_data;
 308         timer = devp->hd_timer;
 309
 310         spin_lock_irq(&hpet_lock);
 311
 312         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 313                &timer->hpet_config);
 314
 315         irq = devp->hd_irq;
 316         devp->hd_irq = 0;
 317
 318         devp->hd_ireqfreq = 0;
 319
 320         if (devp->hd_flags & HPET_PERIODIC
 321             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 322                 unsigned long v;
 323
 324                 v = readq(&timer->hpet_config);
 325                 v ^= Tn_TYPE_CNF_MASK;
 326                 writeq(v, &timer->hpet_config);
 327         }
 328
 329         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 330         spin_unlock_irq(&hpet_lock);
 331
 332         if (irq)
 333                 free_irq(irq, devp);
 334
 335         if (file->f_flags & FASYNC)
 336                 hpet_fasync(-1, file, 0);
 337
 338         file->private_data = NULL;
 339         return 0;
 340 }
 341
 342 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 343
 344 static int
 345 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 346            unsigned long arg)
 347 {
 348         struct hpet_dev *devp;
 349
 350         devp = file->private_data;
 351         return hpet_ioctl_common(devp, cmd, arg, 0);
 352 }
 353
 354 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 355 {
 356         struct hpet_timer __iomem *timer;
 357         struct hpet __iomem *hpet;
 358         struct hpets *hpetp;
 359         int irq;
 360         unsigned long g, v, t, m;
 361         unsigned long flags, isr;
 362
 363         timer = devp->hd_timer;
 364         hpet = devp->hd_hpet;
 365         hpetp = devp->hd_hpets;
 366
 367         if (!devp->hd_ireqfreq)
 368                 return -EIO;
 369
 370         v = readq(&timer->hpet_config);
 371         spin_lock_irq(&hpet_lock);
 372
 373         if (devp->hd_flags & HPET_IE) {
 374                 spin_unlock_irq(&hpet_lock);
 375                 return -EBUSY;
 376         }
 377
 378         devp->hd_flags |= HPET_IE;
 379         spin_unlock_irq(&hpet_lock);
 380
 381         t = readq(&timer->hpet_config);
 382         irq = devp->hd_hdwirq;
 383
 384         if (irq) {
 385                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 386
 387                 if (request_irq
 388                     (irq, hpet_interrupt, SA_INTERRUPT, devp->hd_name, (void *)devp)) {
 389                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 390                         irq = 0;
 391                 }
 392         }
 393
 394         if (irq == 0) {
 395                 spin_lock_irq(&hpet_lock);
 396                 devp->hd_flags ^= HPET_IE;
 397                 spin_unlock_irq(&hpet_lock);
 398                 return -EIO;
 399         }
 400
 401         devp->hd_irq = irq;
 402         t = devp->hd_ireqfreq;
 403         v = readq(&timer->hpet_config);
 404         g = v | Tn_INT_ENB_CNF_MASK;
 405
 406         if (devp->hd_flags & HPET_PERIODIC) {
 407                 write_counter(t, &timer->hpet_compare);
 408                 g |= Tn_TYPE_CNF_MASK;
 409                 v |= Tn_TYPE_CNF_MASK;
 410                 writeq(v, &timer->hpet_config);
 411                 v |= Tn_VAL_SET_CNF_MASK;
 412                 writeq(v, &timer->hpet_config);
 413                 local_irq_save(flags);
 414                 m = read_counter(&hpet->hpet_mc);
 415                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 416         } else {
 417                 local_irq_save(flags);
 418                 m = read_counter(&hpet->hpet_mc);
 419                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 420         }
 421
 422         isr = (1 << (devp - hpets->hp_dev));
 423         writeq(isr, &hpet->hpet_isr);
 424         writeq(g, &timer->hpet_config);
 425         local_irq_restore(flags);
 426
 427         return 0;
 428 }
 429
 430 /* converts Hz to number of timer ticks */
 431 static inline unsigned long hpet_time_div(struct hpets *hpets,
 432                                           unsigned long dis)
 433 {
 434         unsigned long long m;
 435
 436         m = hpets->hp_tick_freq + (dis >> 1);
 437         do_div(m, dis);
 438         return (unsigned long)m;
 439 }
 440
 441 static int
 442 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 443 {
 444         struct hpet_timer __iomem *timer;
 445         struct hpet __iomem *hpet;
 446         struct hpets *hpetp;
 447         int err;
 448         unsigned long v;
 449
 450         switch (cmd) {
 451         case HPET_IE_OFF:
 452         case HPET_INFO:
 453         case HPET_EPI:
 454         case HPET_DPI:
 455         case HPET_IRQFREQ:
 456                 timer = devp->hd_timer;
 457                 hpet = devp->hd_hpet;
 458                 hpetp = devp->hd_hpets;
 459                 break;
 460         case HPET_IE_ON:
 461                 return hpet_ioctl_ieon(devp);
 462         default:
 463                 return -EINVAL;
 464         }
 465
 466         err = 0;
 467
 468         switch (cmd) {
 469         case HPET_IE_OFF:
 470                 if ((devp->hd_flags & HPET_IE) == 0)
 471                         break;
 472                 v = readq(&timer->hpet_config);
 473                 v &= ~Tn_INT_ENB_CNF_MASK;
 474                 writeq(v, &timer->hpet_config);
 475                 if (devp->hd_irq) {
 476                         free_irq(devp->hd_irq, devp);
 477                         devp->hd_irq = 0;
 478                 }
 479                 devp->hd_flags ^= HPET_IE;
 480                 break;
 481         case HPET_INFO:
 482                 {
 483                         struct hpet_info info;
 484
 485                         info.hi_ireqfreq = hpet_time_div(hpetp,
 486                                                          devp->hd_ireqfreq);
 487                         info.hi_flags =
 488                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 489                         info.hi_hpet = devp->hd_hpets->hp_which;
 490                         info.hi_timer = devp - devp->hd_hpets->hp_dev;
 491                         if (copy_to_user((void __user *)arg, &info, sizeof(info)))
 492                                 err = -EFAULT;
 493                         break;
 494                 }
 495         case HPET_EPI:
 496                 v = readq(&timer->hpet_config);
 497                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 498                         err = -ENXIO;
 499                         break;
 500                 }
 501                 devp->hd_flags |= HPET_PERIODIC;
 502                 break;
 503         case HPET_DPI:
 504                 v = readq(&timer->hpet_config);
 505                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 506                         err = -ENXIO;
 507                         break;
 508                 }
 509                 if (devp->hd_flags & HPET_PERIODIC &&
 510                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 511                         v = readq(&timer->hpet_config);
 512                         v ^= Tn_TYPE_CNF_MASK;
 513                         writeq(v, &timer->hpet_config);
 514                 }
 515                 devp->hd_flags &= ~HPET_PERIODIC;
 516                 break;
 517         case HPET_IRQFREQ:
 518                 if (!kernel && (arg > hpet_max_freq) &&
 519                     !capable(CAP_SYS_RESOURCE)) {
 520                         err = -EACCES;
 521                         break;
 522                 }
 523
 524                 if (!arg || (arg & (arg - 1))) {
 525                         err = -EINVAL;
 526                         break;
 527                 }
 528
 529                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 530         }
 531
 532         return err;
 533 }
 534
 535 static struct file_operations hpet_fops = {
 536         .owner = THIS_MODULE,
 537         .llseek = no_llseek,
 538         .read = hpet_read,
 539         .poll = hpet_poll,
 540         .ioctl = hpet_ioctl,
 541         .open = hpet_open,
 542         .release = hpet_release,
 543         .fasync = hpet_fasync,
 544         .mmap = hpet_mmap,
 545 };
 546
 547 EXPORT_SYMBOL(hpet_alloc);
 548 EXPORT_SYMBOL(hpet_register);
 549 EXPORT_SYMBOL(hpet_unregister);
 550 EXPORT_SYMBOL(hpet_control);
 551
 552 int hpet_register(struct hpet_task *tp, int periodic)
 553 {
 554         unsigned int i;
 555         u64 mask;
 556         struct hpet_timer __iomem *timer;
 557         struct hpet_dev *devp;
 558         struct hpets *hpetp;
 559
 560         switch (periodic) {
 561         case 1:
 562                 mask = Tn_PER_INT_CAP_MASK;
 563                 break;
 564         case 0:
 565                 mask = 0;
 566                 break;
 567         default:
 568                 return -EINVAL;
 569         }
 570
 571         spin_lock_irq(&hpet_task_lock);
 572         spin_lock(&hpet_lock);
 573
 574         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 575                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
 576                      i < hpetp->hp_ntimer; i++, timer++) {
 577                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
 578                             != mask)
 579                                 continue;
 580
 581                         devp = &hpetp->hp_dev[i];
 582
 583                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
 584                                 devp = NULL;
 585                                 continue;
 586                         }
 587
 588                         tp->ht_opaque = devp;
 589                         devp->hd_task = tp;
 590                         break;
 591                 }
 592
 593         spin_unlock(&hpet_lock);
 594         spin_unlock_irq(&hpet_task_lock);
 595
 596         if (tp->ht_opaque)
 597                 return 0;
 598         else
 599                 return -EBUSY;
 600 }
 601
 602 static inline int hpet_tpcheck(struct hpet_task *tp)
 603 {
 604         struct hpet_dev *devp;
 605         struct hpets *hpetp;
 606
 607         devp = tp->ht_opaque;
 608
 609         if (!devp)
 610                 return -ENXIO;
 611
 612         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 613                 if (devp >= hpetp->hp_dev
 614                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 615                     && devp->hd_hpet == hpetp->hp_hpet)
 616                         return 0;
 617
 618         return -ENXIO;
 619 }
 620
 621 int hpet_unregister(struct hpet_task *tp)
 622 {
 623         struct hpet_dev *devp;
 624         struct hpet_timer __iomem *timer;
 625         int err;
 626
 627         if ((err = hpet_tpcheck(tp)))
 628                 return err;
 629
 630         spin_lock_irq(&hpet_task_lock);
 631         spin_lock(&hpet_lock);
 632
 633         devp = tp->ht_opaque;
 634         if (devp->hd_task != tp) {
 635                 spin_unlock(&hpet_lock);
 636                 spin_unlock_irq(&hpet_task_lock);
 637                 return -ENXIO;
 638         }
 639
 640         timer = devp->hd_timer;
 641         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 642                &timer->hpet_config);
 643         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 644         devp->hd_task = NULL;
 645         spin_unlock(&hpet_lock);
 646         spin_unlock_irq(&hpet_task_lock);
 647
 648         return 0;
 649 }
 650
 651 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
 652 {
 653         struct hpet_dev *devp;
 654         int err;
 655
 656         if ((err = hpet_tpcheck(tp)))
 657                 return err;
 658
 659         spin_lock_irq(&hpet_lock);
 660         devp = tp->ht_opaque;
 661         if (devp->hd_task != tp) {
 662                 spin_unlock_irq(&hpet_lock);
 663                 return -ENXIO;
 664         }
 665         spin_unlock_irq(&hpet_lock);
 666         return hpet_ioctl_common(devp, cmd, arg, 1);
 667 }
 668
 669 static ctl_table hpet_table[] = {
 670         {
 671          .ctl_name = 1,
 672          .procname = "max-user-freq",
 673          .data = &hpet_max_freq,
 674          .maxlen = sizeof(int),
 675          .mode = 0644,
 676          .proc_handler = &proc_dointvec,
 677          },
 678         {.ctl_name = 0}
 679 };
 680
 681 static ctl_table hpet_root[] = {
 682         {
 683          .ctl_name = 1,
 684          .procname = "hpet",
 685          .maxlen = 0,
 686          .mode = 0555,
 687          .child = hpet_table,
 688          },
 689         {.ctl_name = 0}
 690 };
 691
 692 static ctl_table dev_root[] = {
 693         {
 694          .ctl_name = CTL_DEV,
 695          .procname = "dev",
 696          .maxlen = 0,
 697          .mode = 0555,
 698          .child = hpet_root,
 699          },
 700         {.ctl_name = 0}
 701 };
 702
 703 static struct ctl_table_header *sysctl_header;
 704
 705 static void hpet_register_interpolator(struct hpets *hpetp)
 706 {
 707 #ifdef  CONFIG_TIME_INTERPOLATION
 708         struct time_interpolator *ti;
 709
 710         ti = kmalloc(sizeof(*ti), GFP_KERNEL);
 711         if (!ti)
 712                 return;
 713
 714         memset(ti, 0, sizeof(*ti));
 715         ti->source = TIME_SOURCE_MMIO64;
 716         ti->shift = 10;
 717         ti->addr = &hpetp->hp_hpet->hpet_mc;
 718         ti->frequency = hpetp->hp_tick_freq;
 719         ti->drift = HPET_DRIFT;
 720         ti->mask = -1;
 721
 722         hpetp->hp_interpolator = ti;
 723         register_time_interpolator(ti);
 724 #endif
 725 }
 726
 727 /*
 728  * Adjustment for when arming the timer with
 729  * initial conditions.  That is, main counter
 730  * ticks expired before interrupts are enabled.
 731  */
 732 #define TICK_CALIBRATE  (1000UL)
 733
 734 static unsigned long hpet_calibrate(struct hpets *hpetp)
 735 {
 736         struct hpet_timer __iomem *timer = NULL;
 737         unsigned long t, m, count, i, flags, start;
 738         struct hpet_dev *devp;
 739         int j;
 740         struct hpet __iomem *hpet;
 741
 742         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 743                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 744                         timer = devp->hd_timer;
 745                         break;
 746                 }
 747
 748         if (!timer)
 749                 return 0;
 750
 751         hpet = hpets->hp_hpet;
 752         t = read_counter(&timer->hpet_compare);
 753
 754         i = 0;
 755         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 756
 757         local_irq_save(flags);
 758
 759         start = read_counter(&hpet->hpet_mc);
 760
 761         do {
 762                 m = read_counter(&hpet->hpet_mc);
 763                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 764         } while (i++, (m - start) < count);
 765
 766         local_irq_restore(flags);
 767
 768         return (m - start) / i;
 769 }
 770
 771 int hpet_alloc(struct hpet_data *hdp)
 772 {
 773         u64 cap, mcfg;
 774         struct hpet_dev *devp;
 775         u32 i, ntimer;
 776         struct hpets *hpetp;
 777         size_t siz;
 778         struct hpet __iomem *hpet;
 779         static struct hpets *last = (struct hpets *)0;
 780         unsigned long ns, period;
 781         unsigned long long temp;
 782
 783         /*
 784          * hpet_alloc can be called by platform dependent code.
 785          * if platform dependent code has allocated the hpet
 786          * ACPI also reports hpet, then we catch it here.
 787          */
 788         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 789                 if (hpetp->hp_hpet == hdp->hd_address)
 790                         return 0;
 791
 792         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 793                                       sizeof(struct hpet_dev));
 794
 795         hpetp = kmalloc(siz, GFP_KERNEL);
 796
 797         if (!hpetp)
 798                 return -ENOMEM;
 799
 800         memset(hpetp, 0, siz);
 801
 802         hpetp->hp_which = hpet_nhpet++;
 803         hpetp->hp_hpet = hdp->hd_address;
 804         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 805
 806         hpetp->hp_ntimer = hdp->hd_nirqs;
 807
 808         for (i = 0; i < hdp->hd_nirqs; i++)
 809                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 810
 811         hpet = hpetp->hp_hpet;
 812
 813         cap = readq(&hpet->hpet_cap);
 814
 815         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 816
 817         if (hpetp->hp_ntimer != ntimer) {
 818                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 819                        " with number of timers\n");
 820                 kfree(hpetp);
 821                 return -ENODEV;
 822         }
 823
 824         if (last)
 825                 last->hp_next = hpetp;
 826         else
 827                 hpets = hpetp;
 828
 829         last = hpetp;
 830
 831         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 832                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 833         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 834         temp += period >> 1; /* round */
 835         do_div(temp, period);
 836         hpetp->hp_tick_freq = temp; /* ticks per second */
 837
 838         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 839                 hpetp->hp_which, hdp->hd_phys_address,
 840                 hpetp->hp_ntimer > 1 ? "s" : "");
 841         for (i = 0; i < hpetp->hp_ntimer; i++)
 842                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 843         printk("\n");
 844
 845         ns = period / 1000000;  /* convert to nanoseconds, 10^-9 */
 846         printk(KERN_INFO "hpet%d: %ldns tick, %d %d-bit timers\n",
 847                 hpetp->hp_which, ns, hpetp->hp_ntimer,
 848                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32);
 849
 850         mcfg = readq(&hpet->hpet_config);
 851         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 852                 write_counter(0L, &hpet->hpet_mc);
 853                 mcfg |= HPET_ENABLE_CNF_MASK;
 854                 writeq(mcfg, &hpet->hpet_config);
 855         }
 856
 857         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 858                 unsigned long v;
 859                 struct hpet_timer __iomem *timer;
 860
 861                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 862                 v = readq(&timer->hpet_config);
 863
 864                 devp->hd_hpets = hpetp;
 865                 devp->hd_hpet = hpet;
 866                 devp->hd_timer = timer;
 867
 868                 /*
 869                  * If the timer was reserved by platform code,
 870                  * then make timer unavailable for opens.
 871                  */
 872                 if (hdp->hd_state & (1 << i)) {
 873                         devp->hd_flags = HPET_OPEN;
 874                         continue;
 875                 }
 876
 877                 init_waitqueue_head(&devp->hd_waitqueue);
 878         }
 879
 880         hpetp->hp_delta = hpet_calibrate(hpetp);
 881         hpet_register_interpolator(hpetp);
 882
 883         return 0;
 884 }
 885
 886 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 887 {
 888         struct hpet_data *hdp;
 889         acpi_status status;
 890         struct acpi_resource_address64 addr;
 891         struct hpets *hpetp;
 892
 893         hdp = data;
 894
 895         status = acpi_resource_to_address64(res, &addr);
 896
 897         if (ACPI_SUCCESS(status)) {
 898                 unsigned long size;
 899
 900                 size = addr.max_address_range - addr.min_address_range + 1;
 901                 hdp->hd_phys_address = addr.min_address_range;
 902                 hdp->hd_address = ioremap(addr.min_address_range, size);
 903
 904                 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 905                         if (hpetp->hp_hpet == hdp->hd_address)
 906                                 return -EBUSY;
 907         } else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
 908                 struct acpi_resource_ext_irq *irqp;
 909                 int i;
 910
 911                 irqp = &res->data.extended_irq;
 912
 913                 if (irqp->number_of_interrupts > 0) {
 914                         hdp->hd_nirqs = irqp->number_of_interrupts;
 915
 916                         for (i = 0; i < hdp->hd_nirqs; i++) {
 917                                 int rc =
 918                                     acpi_register_gsi(irqp->interrupts[i],
 919                                                       irqp->edge_level,
 920                                                       irqp->active_high_low);
 921                                 if (rc < 0)
 922                                         return AE_ERROR;
 923                                 hdp->hd_irq[i] = rc;
 924                         }
 925                 }
 926         }
 927
 928         return AE_OK;
 929 }
 930
 931 static int hpet_acpi_add(struct acpi_device *device)
 932 {
 933         acpi_status result;
 934         struct hpet_data data;
 935
 936         memset(&data, 0, sizeof(data));
 937
 938         result =
 939             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 940                                 hpet_resources, &data);
 941
 942         if (ACPI_FAILURE(result))
 943                 return -ENODEV;
 944
 945         if (!data.hd_address || !data.hd_nirqs) {
 946                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
 947                 return -ENODEV;
 948         }
 949
 950         return hpet_alloc(&data);
 951 }
 952
 953 static int hpet_acpi_remove(struct acpi_device *device, int type)
 954 {
 955         /* XXX need to unregister interpolator, dealloc mem, etc */
 956         return -EINVAL;
 957 }
 958
 959 static struct acpi_driver hpet_acpi_driver = {
 960         .name = "hpet",
 961         .ids = "PNP0103",
 962         .ops = {
 963                 .add = hpet_acpi_add,
 964                 .remove = hpet_acpi_remove,
 965                 },
 966 };
 967
 968 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
 969
 970 static int __init hpet_init(void)
 971 {
 972         int result;
 973
 974         result = misc_register(&hpet_misc);
 975         if (result < 0)
 976                 return -ENODEV;
 977
 978         sysctl_header = register_sysctl_table(dev_root, 0);
 979
 980         result = acpi_bus_register_driver(&hpet_acpi_driver);
 981         if (result < 0) {
 982                 if (sysctl_header)
 983                         unregister_sysctl_table(sysctl_header);
 984                 misc_deregister(&hpet_misc);
 985                 return result;
 986         }
 987
 988         return 0;
 989 }
 990
 991 static void __exit hpet_exit(void)
 992 {
 993         acpi_bus_unregister_driver(&hpet_acpi_driver);
 994
 995         if (sysctl_header)
 996                 unregister_sysctl_table(sysctl_header);
 997         misc_deregister(&hpet_misc);
 998
 999         return;
1000 }
1001
1002 module_init(hpet_init);
1003 module_exit(hpet_exit);
1004 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1005 MODULE_LICENSE("GPL");