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