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