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
  33 #include <asm/current.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/system.h>
  36 #include <asm/io.h>
  37 #include <asm/irq.h>
  38 #include <asm/div64.h>
  39
  40 #include <linux/acpi.h>
  41 #include <acpi/acpi_bus.h>
  42 #include <linux/hpet.h>
  43
  44 /*
  45  * The High Precision Event Timer driver.
  46  * This driver is closely modelled after the rtc.c driver.
  47  * http://www.intel.com/hardwaredesign/hpetspec.htm
  48  */
  49 #define HPET_USER_FREQ  (64)
  50 #define HPET_DRIFT      (500)
  51
  52 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  53
  54 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  55
  56 /* A lock for concurrent access by app and isr hpet activity. */
  57 static DEFINE_SPINLOCK(hpet_lock);
  58 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  59 static DEFINE_SPINLOCK(hpet_task_lock);
  60
  61 #define HPET_DEV_NAME   (7)
  62
  63 struct hpet_dev {
  64         struct hpets *hd_hpets;
  65         struct hpet __iomem *hd_hpet;
  66         struct hpet_timer __iomem *hd_timer;
  67         unsigned long hd_ireqfreq;
  68         unsigned long hd_irqdata;
  69         wait_queue_head_t hd_waitqueue;
  70         struct fasync_struct *hd_async_queue;
  71         struct hpet_task *hd_task;
  72         unsigned int hd_flags;
  73         unsigned int hd_irq;
  74         unsigned int hd_hdwirq;
  75         char hd_name[HPET_DEV_NAME];
  76 };
  77
  78 struct hpets {
  79         struct hpets *hp_next;
  80         struct hpet __iomem *hp_hpet;
  81         unsigned long hp_hpet_phys;
  82         struct time_interpolator *hp_interpolator;
  83         unsigned long long hp_tick_freq;
  84         unsigned long hp_delta;
  85         unsigned int hp_ntimer;
  86         unsigned int hp_which;
  87         struct hpet_dev hp_dev[1];
  88 };
  89
  90 static struct hpets *hpets;
  91
  92 #define HPET_OPEN               0x0001
  93 #define HPET_IE                 0x0002  /* interrupt enabled */
  94 #define HPET_PERIODIC           0x0004
  95 #define HPET_SHARED_IRQ         0x0008
  96
  97 #if BITS_PER_LONG == 64
  98 #define write_counter(V, MC)    writeq(V, MC)
  99 #define read_counter(MC)        readq(MC)
 100 #else
 101 #define write_counter(V, MC)    writel(V, MC)
 102 #define read_counter(MC)        readl(MC)
 103 #endif
 104
 105 #ifndef readq
 106 static inline unsigned long long readq(void __iomem *addr)
 107 {
 108         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 109 }
 110 #endif
 111
 112 #ifndef writeq
 113 static inline void writeq(unsigned long long v, void __iomem *addr)
 114 {
 115         writel(v & 0xffffffff, addr);
 116         writel(v >> 32, addr + 4);
 117 }
 118 #endif
 119
 120 static irqreturn_t hpet_interrupt(int irq, void *data)
 121 {
 122         struct hpet_dev *devp;
 123         unsigned long isr;
 124
 125         devp = data;
 126         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 127
 128         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 129             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 130                 return IRQ_NONE;
 131
 132         spin_lock(&hpet_lock);
 133         devp->hd_irqdata++;
 134
 135         /*
 136          * For non-periodic timers, increment the accumulator.
 137          * This has the effect of treating non-periodic like periodic.
 138          */
 139         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 140                 unsigned long m, t;
 141
 142                 t = devp->hd_ireqfreq;
 143                 m = read_counter(&devp->hd_hpet->hpet_mc);
 144                 write_counter(t + m + devp->hd_hpets->hp_delta,
 145                               &devp->hd_timer->hpet_compare);
 146         }
 147
 148         if (devp->hd_flags & HPET_SHARED_IRQ)
 149                 writel(isr, &devp->hd_hpet->hpet_isr);
 150         spin_unlock(&hpet_lock);
 151
 152         spin_lock(&hpet_task_lock);
 153         if (devp->hd_task)
 154                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 155         spin_unlock(&hpet_task_lock);
 156
 157         wake_up_interruptible(&devp->hd_waitqueue);
 158
 159         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 160
 161         return IRQ_HANDLED;
 162 }
 163
 164 static int hpet_open(struct inode *inode, struct file *file)
 165 {
 166         struct hpet_dev *devp;
 167         struct hpets *hpetp;
 168         int i;
 169
 170         if (file->f_mode & FMODE_WRITE)
 171                 return -EINVAL;
 172
 173         spin_lock_irq(&hpet_lock);
 174
 175         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 176                 for (i = 0; i < hpetp->hp_ntimer; i++)
 177                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 178                             || hpetp->hp_dev[i].hd_task)
 179                                 continue;
 180                         else {
 181                                 devp = &hpetp->hp_dev[i];
 182                                 break;
 183                         }
 184
 185         if (!devp) {
 186                 spin_unlock_irq(&hpet_lock);
 187                 return -EBUSY;
 188         }
 189
 190         file->private_data = devp;
 191         devp->hd_irqdata = 0;
 192         devp->hd_flags |= HPET_OPEN;
 193         spin_unlock_irq(&hpet_lock);
 194
 195         return 0;
 196 }
 197
 198 static ssize_t
 199 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 200 {
 201         DECLARE_WAITQUEUE(wait, current);
 202         unsigned long data;
 203         ssize_t retval;
 204         struct hpet_dev *devp;
 205
 206         devp = file->private_data;
 207         if (!devp->hd_ireqfreq)
 208                 return -EIO;
 209
 210         if (count < sizeof(unsigned long))
 211                 return -EINVAL;
 212
 213         add_wait_queue(&devp->hd_waitqueue, &wait);
 214
 215         for ( ; ; ) {
 216                 set_current_state(TASK_INTERRUPTIBLE);
 217
 218                 spin_lock_irq(&hpet_lock);
 219                 data = devp->hd_irqdata;
 220                 devp->hd_irqdata = 0;
 221                 spin_unlock_irq(&hpet_lock);
 222
 223                 if (data)
 224                         break;
 225                 else if (file->f_flags & O_NONBLOCK) {
 226                         retval = -EAGAIN;
 227                         goto out;
 228                 } else if (signal_pending(current)) {
 229                         retval = -ERESTARTSYS;
 230                         goto out;
 231                 }
 232                 schedule();
 233         }
 234
 235         retval = put_user(data, (unsigned long __user *)buf);
 236         if (!retval)
 237                 retval = sizeof(unsigned long);
 238 out:
 239         __set_current_state(TASK_RUNNING);
 240         remove_wait_queue(&devp->hd_waitqueue, &wait);
 241
 242         return retval;
 243 }
 244
 245 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 246 {
 247         unsigned long v;
 248         struct hpet_dev *devp;
 249
 250         devp = file->private_data;
 251
 252         if (!devp->hd_ireqfreq)
 253                 return 0;
 254
 255         poll_wait(file, &devp->hd_waitqueue, wait);
 256
 257         spin_lock_irq(&hpet_lock);
 258         v = devp->hd_irqdata;
 259         spin_unlock_irq(&hpet_lock);
 260
 261         if (v != 0)
 262                 return POLLIN | POLLRDNORM;
 263
 264         return 0;
 265 }
 266
 267 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 268 {
 269 #ifdef  CONFIG_HPET_MMAP
 270         struct hpet_dev *devp;
 271         unsigned long addr;
 272
 273         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 274                 return -EINVAL;
 275
 276         devp = file->private_data;
 277         addr = devp->hd_hpets->hp_hpet_phys;
 278
 279         if (addr & (PAGE_SIZE - 1))
 280                 return -ENOSYS;
 281
 282         vma->vm_flags |= VM_IO;
 283         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 284
 285         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 286                                         PAGE_SIZE, vma->vm_page_prot)) {
 287                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
 288                         __FUNCTION__);
 289                 return -EAGAIN;
 290         }
 291
 292         return 0;
 293 #else
 294         return -ENOSYS;
 295 #endif
 296 }
 297
 298 static int hpet_fasync(int fd, struct file *file, int on)
 299 {
 300         struct hpet_dev *devp;
 301
 302         devp = file->private_data;
 303
 304         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 305                 return 0;
 306         else
 307                 return -EIO;
 308 }
 309
 310 static int hpet_release(struct inode *inode, struct file *file)
 311 {
 312         struct hpet_dev *devp;
 313         struct hpet_timer __iomem *timer;
 314         int irq = 0;
 315
 316         devp = file->private_data;
 317         timer = devp->hd_timer;
 318
 319         spin_lock_irq(&hpet_lock);
 320
 321         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 322                &timer->hpet_config);
 323
 324         irq = devp->hd_irq;
 325         devp->hd_irq = 0;
 326
 327         devp->hd_ireqfreq = 0;
 328
 329         if (devp->hd_flags & HPET_PERIODIC
 330             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 331                 unsigned long v;
 332
 333                 v = readq(&timer->hpet_config);
 334                 v ^= Tn_TYPE_CNF_MASK;
 335                 writeq(v, &timer->hpet_config);
 336         }
 337
 338         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 339         spin_unlock_irq(&hpet_lock);
 340
 341         if (irq)
 342                 free_irq(irq, devp);
 343
 344         if (file->f_flags & FASYNC)
 345                 hpet_fasync(-1, file, 0);
 346
 347         file->private_data = NULL;
 348         return 0;
 349 }
 350
 351 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 352
 353 static int
 354 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 355            unsigned long arg)
 356 {
 357         struct hpet_dev *devp;
 358
 359         devp = file->private_data;
 360         return hpet_ioctl_common(devp, cmd, arg, 0);
 361 }
 362
 363 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 364 {
 365         struct hpet_timer __iomem *timer;
 366         struct hpet __iomem *hpet;
 367         struct hpets *hpetp;
 368         int irq;
 369         unsigned long g, v, t, m;
 370         unsigned long flags, isr;
 371
 372         timer = devp->hd_timer;
 373         hpet = devp->hd_hpet;
 374         hpetp = devp->hd_hpets;
 375
 376         if (!devp->hd_ireqfreq)
 377                 return -EIO;
 378
 379         spin_lock_irq(&hpet_lock);
 380
 381         if (devp->hd_flags & HPET_IE) {
 382                 spin_unlock_irq(&hpet_lock);
 383                 return -EBUSY;
 384         }
 385
 386         devp->hd_flags |= HPET_IE;
 387
 388         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 389                 devp->hd_flags |= HPET_SHARED_IRQ;
 390         spin_unlock_irq(&hpet_lock);
 391
 392         irq = devp->hd_hdwirq;
 393
 394         if (irq) {
 395                 unsigned long irq_flags;
 396
 397                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 398                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 399                                                 ? IRQF_SHARED : IRQF_DISABLED;
 400                 if (request_irq(irq, hpet_interrupt, irq_flags,
 401                                 devp->hd_name, (void *)devp)) {
 402                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 403                         irq = 0;
 404                 }
 405         }
 406
 407         if (irq == 0) {
 408                 spin_lock_irq(&hpet_lock);
 409                 devp->hd_flags ^= HPET_IE;
 410                 spin_unlock_irq(&hpet_lock);
 411                 return -EIO;
 412         }
 413
 414         devp->hd_irq = irq;
 415         t = devp->hd_ireqfreq;
 416         v = readq(&timer->hpet_config);
 417         g = v | Tn_INT_ENB_CNF_MASK;
 418
 419         if (devp->hd_flags & HPET_PERIODIC) {
 420                 write_counter(t, &timer->hpet_compare);
 421                 g |= Tn_TYPE_CNF_MASK;
 422                 v |= Tn_TYPE_CNF_MASK;
 423                 writeq(v, &timer->hpet_config);
 424                 v |= Tn_VAL_SET_CNF_MASK;
 425                 writeq(v, &timer->hpet_config);
 426                 local_irq_save(flags);
 427                 m = read_counter(&hpet->hpet_mc);
 428                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 429         } else {
 430                 local_irq_save(flags);
 431                 m = read_counter(&hpet->hpet_mc);
 432                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 433         }
 434
 435         if (devp->hd_flags & HPET_SHARED_IRQ) {
 436                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 437                 writel(isr, &hpet->hpet_isr);
 438         }
 439         writeq(g, &timer->hpet_config);
 440         local_irq_restore(flags);
 441
 442         return 0;
 443 }
 444
 445 /* converts Hz to number of timer ticks */
 446 static inline unsigned long hpet_time_div(struct hpets *hpets,
 447                                           unsigned long dis)
 448 {
 449         unsigned long long m;
 450
 451         m = hpets->hp_tick_freq + (dis >> 1);
 452         do_div(m, dis);
 453         return (unsigned long)m;
 454 }
 455
 456 static int
 457 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 458 {
 459         struct hpet_timer __iomem *timer;
 460         struct hpet __iomem *hpet;
 461         struct hpets *hpetp;
 462         int err;
 463         unsigned long v;
 464
 465         switch (cmd) {
 466         case HPET_IE_OFF:
 467         case HPET_INFO:
 468         case HPET_EPI:
 469         case HPET_DPI:
 470         case HPET_IRQFREQ:
 471                 timer = devp->hd_timer;
 472                 hpet = devp->hd_hpet;
 473                 hpetp = devp->hd_hpets;
 474                 break;
 475         case HPET_IE_ON:
 476                 return hpet_ioctl_ieon(devp);
 477         default:
 478                 return -EINVAL;
 479         }
 480
 481         err = 0;
 482
 483         switch (cmd) {
 484         case HPET_IE_OFF:
 485                 if ((devp->hd_flags & HPET_IE) == 0)
 486                         break;
 487                 v = readq(&timer->hpet_config);
 488                 v &= ~Tn_INT_ENB_CNF_MASK;
 489                 writeq(v, &timer->hpet_config);
 490                 if (devp->hd_irq) {
 491                         free_irq(devp->hd_irq, devp);
 492                         devp->hd_irq = 0;
 493                 }
 494                 devp->hd_flags ^= HPET_IE;
 495                 break;
 496         case HPET_INFO:
 497                 {
 498                         struct hpet_info info;
 499
 500                         if (devp->hd_ireqfreq)
 501                                 info.hi_ireqfreq =
 502                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 503                         else
 504                                 info.hi_ireqfreq = 0;
 505                         info.hi_flags =
 506                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 507                         info.hi_hpet = hpetp->hp_which;
 508                         info.hi_timer = devp - hpetp->hp_dev;
 509                         if (kernel)
 510                                 memcpy((void *)arg, &info, sizeof(info));
 511                         else
 512                                 if (copy_to_user((void __user *)arg, &info,
 513                                                  sizeof(info)))
 514                                         err = -EFAULT;
 515                         break;
 516                 }
 517         case HPET_EPI:
 518                 v = readq(&timer->hpet_config);
 519                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 520                         err = -ENXIO;
 521                         break;
 522                 }
 523                 devp->hd_flags |= HPET_PERIODIC;
 524                 break;
 525         case HPET_DPI:
 526                 v = readq(&timer->hpet_config);
 527                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 528                         err = -ENXIO;
 529                         break;
 530                 }
 531                 if (devp->hd_flags & HPET_PERIODIC &&
 532                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 533                         v = readq(&timer->hpet_config);
 534                         v ^= Tn_TYPE_CNF_MASK;
 535                         writeq(v, &timer->hpet_config);
 536                 }
 537                 devp->hd_flags &= ~HPET_PERIODIC;
 538                 break;
 539         case HPET_IRQFREQ:
 540                 if (!kernel && (arg > hpet_max_freq) &&
 541                     !capable(CAP_SYS_RESOURCE)) {
 542                         err = -EACCES;
 543                         break;
 544                 }
 545
 546                 if (!arg) {
 547                         err = -EINVAL;
 548                         break;
 549                 }
 550
 551                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 552         }
 553
 554         return err;
 555 }
 556
 557 static const struct file_operations hpet_fops = {
 558         .owner = THIS_MODULE,
 559         .llseek = no_llseek,
 560         .read = hpet_read,
 561         .poll = hpet_poll,
 562         .ioctl = hpet_ioctl,
 563         .open = hpet_open,
 564         .release = hpet_release,
 565         .fasync = hpet_fasync,
 566         .mmap = hpet_mmap,
 567 };
 568
 569 static int hpet_is_known(struct hpet_data *hdp)
 570 {
 571         struct hpets *hpetp;
 572
 573         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 574                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 575                         return 1;
 576
 577         return 0;
 578 }
 579
 580 EXPORT_SYMBOL(hpet_alloc);
 581 EXPORT_SYMBOL(hpet_register);
 582 EXPORT_SYMBOL(hpet_unregister);
 583 EXPORT_SYMBOL(hpet_control);
 584
 585 int hpet_register(struct hpet_task *tp, int periodic)
 586 {
 587         unsigned int i;
 588         u64 mask;
 589         struct hpet_timer __iomem *timer;
 590         struct hpet_dev *devp;
 591         struct hpets *hpetp;
 592
 593         switch (periodic) {
 594         case 1:
 595                 mask = Tn_PER_INT_CAP_MASK;
 596                 break;
 597         case 0:
 598                 mask = 0;
 599                 break;
 600         default:
 601                 return -EINVAL;
 602         }
 603
 604         tp->ht_opaque = NULL;
 605
 606         spin_lock_irq(&hpet_task_lock);
 607         spin_lock(&hpet_lock);
 608
 609         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 610                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
 611                      i < hpetp->hp_ntimer; i++, timer++) {
 612                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
 613                             != mask)
 614                                 continue;
 615
 616                         devp = &hpetp->hp_dev[i];
 617
 618                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
 619                                 devp = NULL;
 620                                 continue;
 621                         }
 622
 623                         tp->ht_opaque = devp;
 624                         devp->hd_task = tp;
 625                         break;
 626                 }
 627
 628         spin_unlock(&hpet_lock);
 629         spin_unlock_irq(&hpet_task_lock);
 630
 631         if (tp->ht_opaque)
 632                 return 0;
 633         else
 634                 return -EBUSY;
 635 }
 636
 637 static inline int hpet_tpcheck(struct hpet_task *tp)
 638 {
 639         struct hpet_dev *devp;
 640         struct hpets *hpetp;
 641
 642         devp = tp->ht_opaque;
 643
 644         if (!devp)
 645                 return -ENXIO;
 646
 647         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 648                 if (devp >= hpetp->hp_dev
 649                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 650                     && devp->hd_hpet == hpetp->hp_hpet)
 651                         return 0;
 652
 653         return -ENXIO;
 654 }
 655
 656 int hpet_unregister(struct hpet_task *tp)
 657 {
 658         struct hpet_dev *devp;
 659         struct hpet_timer __iomem *timer;
 660         int err;
 661
 662         if ((err = hpet_tpcheck(tp)))
 663                 return err;
 664
 665         spin_lock_irq(&hpet_task_lock);
 666         spin_lock(&hpet_lock);
 667
 668         devp = tp->ht_opaque;
 669         if (devp->hd_task != tp) {
 670                 spin_unlock(&hpet_lock);
 671                 spin_unlock_irq(&hpet_task_lock);
 672                 return -ENXIO;
 673         }
 674
 675         timer = devp->hd_timer;
 676         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 677                &timer->hpet_config);
 678         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 679         devp->hd_task = NULL;
 680         spin_unlock(&hpet_lock);
 681         spin_unlock_irq(&hpet_task_lock);
 682
 683         return 0;
 684 }
 685
 686 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
 687 {
 688         struct hpet_dev *devp;
 689         int err;
 690
 691         if ((err = hpet_tpcheck(tp)))
 692                 return err;
 693
 694         spin_lock_irq(&hpet_lock);
 695         devp = tp->ht_opaque;
 696         if (devp->hd_task != tp) {
 697                 spin_unlock_irq(&hpet_lock);
 698                 return -ENXIO;
 699         }
 700         spin_unlock_irq(&hpet_lock);
 701         return hpet_ioctl_common(devp, cmd, arg, 1);
 702 }
 703
 704 static ctl_table hpet_table[] = {
 705         {
 706          .ctl_name = CTL_UNNUMBERED,
 707          .procname = "max-user-freq",
 708          .data = &hpet_max_freq,
 709          .maxlen = sizeof(int),
 710          .mode = 0644,
 711          .proc_handler = &proc_dointvec,
 712          },
 713         {.ctl_name = 0}
 714 };
 715
 716 static ctl_table hpet_root[] = {
 717         {
 718          .ctl_name = CTL_UNNUMBERED,
 719          .procname = "hpet",
 720          .maxlen = 0,
 721          .mode = 0555,
 722          .child = hpet_table,
 723          },
 724         {.ctl_name = 0}
 725 };
 726
 727 static ctl_table dev_root[] = {
 728         {
 729          .ctl_name = CTL_DEV,
 730          .procname = "dev",
 731          .maxlen = 0,
 732          .mode = 0555,
 733          .child = hpet_root,
 734          },
 735         {.ctl_name = 0}
 736 };
 737
 738 static struct ctl_table_header *sysctl_header;
 739
 740 static void hpet_register_interpolator(struct hpets *hpetp)
 741 {
 742 #ifdef  CONFIG_TIME_INTERPOLATION
 743         struct time_interpolator *ti;
 744
 745         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
 746         if (!ti)
 747                 return;
 748
 749         ti->source = TIME_SOURCE_MMIO64;
 750         ti->shift = 10;
 751         ti->addr = &hpetp->hp_hpet->hpet_mc;
 752         ti->frequency = hpetp->hp_tick_freq;
 753         ti->drift = HPET_DRIFT;
 754         ti->mask = -1;
 755
 756         hpetp->hp_interpolator = ti;
 757         register_time_interpolator(ti);
 758 #endif
 759 }
 760
 761 /*
 762  * Adjustment for when arming the timer with
 763  * initial conditions.  That is, main counter
 764  * ticks expired before interrupts are enabled.
 765  */
 766 #define TICK_CALIBRATE  (1000UL)
 767
 768 static unsigned long hpet_calibrate(struct hpets *hpetp)
 769 {
 770         struct hpet_timer __iomem *timer = NULL;
 771         unsigned long t, m, count, i, flags, start;
 772         struct hpet_dev *devp;
 773         int j;
 774         struct hpet __iomem *hpet;
 775
 776         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 777                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 778                         timer = devp->hd_timer;
 779                         break;
 780                 }
 781
 782         if (!timer)
 783                 return 0;
 784
 785         hpet = hpetp->hp_hpet;
 786         t = read_counter(&timer->hpet_compare);
 787
 788         i = 0;
 789         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 790
 791         local_irq_save(flags);
 792
 793         start = read_counter(&hpet->hpet_mc);
 794
 795         do {
 796                 m = read_counter(&hpet->hpet_mc);
 797                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 798         } while (i++, (m - start) < count);
 799
 800         local_irq_restore(flags);
 801
 802         return (m - start) / i;
 803 }
 804
 805 int hpet_alloc(struct hpet_data *hdp)
 806 {
 807         u64 cap, mcfg;
 808         struct hpet_dev *devp;
 809         u32 i, ntimer;
 810         struct hpets *hpetp;
 811         size_t siz;
 812         struct hpet __iomem *hpet;
 813         static struct hpets *last = NULL;
 814         unsigned long period;
 815         unsigned long long temp;
 816
 817         /*
 818          * hpet_alloc can be called by platform dependent code.
 819          * If platform dependent code has allocated the hpet that
 820          * ACPI has also reported, then we catch it here.
 821          */
 822         if (hpet_is_known(hdp)) {
 823                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 824                         __FUNCTION__);
 825                 return 0;
 826         }
 827
 828         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 829                                       sizeof(struct hpet_dev));
 830
 831         hpetp = kzalloc(siz, GFP_KERNEL);
 832
 833         if (!hpetp)
 834                 return -ENOMEM;
 835
 836         hpetp->hp_which = hpet_nhpet++;
 837         hpetp->hp_hpet = hdp->hd_address;
 838         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 839
 840         hpetp->hp_ntimer = hdp->hd_nirqs;
 841
 842         for (i = 0; i < hdp->hd_nirqs; i++)
 843                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 844
 845         hpet = hpetp->hp_hpet;
 846
 847         cap = readq(&hpet->hpet_cap);
 848
 849         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 850
 851         if (hpetp->hp_ntimer != ntimer) {
 852                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 853                        " with number of timers\n");
 854                 kfree(hpetp);
 855                 return -ENODEV;
 856         }
 857
 858         if (last)
 859                 last->hp_next = hpetp;
 860         else
 861                 hpets = hpetp;
 862
 863         last = hpetp;
 864
 865         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 866                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 867         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 868         temp += period >> 1; /* round */
 869         do_div(temp, period);
 870         hpetp->hp_tick_freq = temp; /* ticks per second */
 871
 872         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 873                 hpetp->hp_which, hdp->hd_phys_address,
 874                 hpetp->hp_ntimer > 1 ? "s" : "");
 875         for (i = 0; i < hpetp->hp_ntimer; i++)
 876                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 877         printk("\n");
 878
 879         printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
 880                hpetp->hp_which, hpetp->hp_ntimer,
 881                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
 882
 883         mcfg = readq(&hpet->hpet_config);
 884         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 885                 write_counter(0L, &hpet->hpet_mc);
 886                 mcfg |= HPET_ENABLE_CNF_MASK;
 887                 writeq(mcfg, &hpet->hpet_config);
 888         }
 889
 890         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 891                 struct hpet_timer __iomem *timer;
 892
 893                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 894
 895                 devp->hd_hpets = hpetp;
 896                 devp->hd_hpet = hpet;
 897                 devp->hd_timer = timer;
 898
 899                 /*
 900                  * If the timer was reserved by platform code,
 901                  * then make timer unavailable for opens.
 902                  */
 903                 if (hdp->hd_state & (1 << i)) {
 904                         devp->hd_flags = HPET_OPEN;
 905                         continue;
 906                 }
 907
 908                 init_waitqueue_head(&devp->hd_waitqueue);
 909         }
 910
 911         hpetp->hp_delta = hpet_calibrate(hpetp);
 912         hpet_register_interpolator(hpetp);
 913
 914         return 0;
 915 }
 916
 917 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 918 {
 919         struct hpet_data *hdp;
 920         acpi_status status;
 921         struct acpi_resource_address64 addr;
 922
 923         hdp = data;
 924
 925         status = acpi_resource_to_address64(res, &addr);
 926
 927         if (ACPI_SUCCESS(status)) {
 928                 hdp->hd_phys_address = addr.minimum;
 929                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 930
 931                 if (hpet_is_known(hdp)) {
 932                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 933                                 __FUNCTION__, hdp->hd_phys_address);
 934                         iounmap(hdp->hd_address);
 935                         return -EBUSY;
 936                 }
 937         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 938                 struct acpi_resource_fixed_memory32 *fixmem32;
 939
 940                 fixmem32 = &res->data.fixed_memory32;
 941                 if (!fixmem32)
 942                         return -EINVAL;
 943
 944                 hdp->hd_phys_address = fixmem32->address;
 945                 hdp->hd_address = ioremap(fixmem32->address,
 946                                                 HPET_RANGE_SIZE);
 947
 948                 if (hpet_is_known(hdp)) {
 949                         printk(KERN_DEBUG "%s: 0x%lx is busy\n",
 950                                 __FUNCTION__, hdp->hd_phys_address);
 951                         iounmap(hdp->hd_address);
 952                         return -EBUSY;
 953                 }
 954         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 955                 struct acpi_resource_extended_irq *irqp;
 956                 int i, irq;
 957
 958                 irqp = &res->data.extended_irq;
 959
 960                 for (i = 0; i < irqp->interrupt_count; i++) {
 961                         irq = acpi_register_gsi(irqp->interrupts[i],
 962                                       irqp->triggering, irqp->polarity);
 963                         if (irq < 0)
 964                                 return AE_ERROR;
 965
 966                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 967                         hdp->hd_nirqs++;
 968                 }
 969         }
 970
 971         return AE_OK;
 972 }
 973
 974 static int hpet_acpi_add(struct acpi_device *device)
 975 {
 976         acpi_status result;
 977         struct hpet_data data;
 978
 979         memset(&data, 0, sizeof(data));
 980
 981         result =
 982             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 983                                 hpet_resources, &data);
 984
 985         if (ACPI_FAILURE(result))
 986                 return -ENODEV;
 987
 988         if (!data.hd_address || !data.hd_nirqs) {
 989                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
 990                 return -ENODEV;
 991         }
 992
 993         return hpet_alloc(&data);
 994 }
 995
 996 static int hpet_acpi_remove(struct acpi_device *device, int type)
 997 {
 998         /* XXX need to unregister interpolator, dealloc mem, etc */
 999         return -EINVAL;
1000 }
1001
1002 static struct acpi_driver hpet_acpi_driver = {
1003         .name = "hpet",
1004         .ids = "PNP0103",
1005         .ops = {
1006                 .add = hpet_acpi_add,
1007                 .remove = hpet_acpi_remove,
1008                 },
1009 };
1010
1011 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1012
1013 static int __init hpet_init(void)
1014 {
1015         int result;
1016
1017         result = misc_register(&hpet_misc);
1018         if (result < 0)
1019                 return -ENODEV;
1020
1021         sysctl_header = register_sysctl_table(dev_root);
1022
1023         result = acpi_bus_register_driver(&hpet_acpi_driver);
1024         if (result < 0) {
1025                 if (sysctl_header)
1026                         unregister_sysctl_table(sysctl_header);
1027                 misc_deregister(&hpet_misc);
1028                 return result;
1029         }
1030
1031         return 0;
1032 }
1033
1034 static void __exit hpet_exit(void)
1035 {
1036         acpi_bus_unregister_driver(&hpet_acpi_driver);
1037
1038         if (sysctl_header)
1039                 unregister_sysctl_table(sysctl_header);
1040         misc_deregister(&hpet_misc);
1041
1042         return;
1043 }
1044
1045 module_init(hpet_init);
1046 module_exit(hpet_exit);
1047 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1048 MODULE_LICENSE("GPL");