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/smp_lock.h>
  18 #include <linux/types.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/major.h>
  21 #include <linux/ioport.h>
  22 #include <linux/fcntl.h>
  23 #include <linux/init.h>
  24 #include <linux/poll.h>
  25 #include <linux/mm.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/sysctl.h>
  29 #include <linux/wait.h>
  30 #include <linux/bcd.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/bitops.h>
  33 #include <linux/compat.h>
  34 #include <linux/clocksource.h>
  35 #include <linux/slab.h>
  36
  37 #include <asm/current.h>
  38 #include <asm/uaccess.h>
  39 #include <asm/system.h>
  40 #include <asm/io.h>
  41 #include <asm/irq.h>
  42 #include <asm/div64.h>
  43
  44 #include <linux/acpi.h>
  45 #include <acpi/acpi_bus.h>
  46 #include <linux/hpet.h>
  47
  48 /*
  49  * The High Precision Event Timer driver.
  50  * This driver is closely modelled after the rtc.c driver.
  51  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
  52  */
  53 #define HPET_USER_FREQ  (64)
  54 #define HPET_DRIFT      (500)
  55
  56 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  57
  58
  59 /* WARNING -- don't get confused.  These macros are never used
  60  * to write the (single) counter, and rarely to read it.
  61  * They're badly named; to fix, someday.
  62  */
  63 #if BITS_PER_LONG == 64
  64 #define write_counter(V, MC)    writeq(V, MC)
  65 #define read_counter(MC)        readq(MC)
  66 #else
  67 #define write_counter(V, MC)    writel(V, MC)
  68 #define read_counter(MC)        readl(MC)
  69 #endif
  70
  71 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
  72 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  73
  74 /* This clocksource driver currently only works on ia64 */
  75 #ifdef CONFIG_IA64
  76 static void __iomem *hpet_mctr;
  77
  78 static cycle_t read_hpet(struct clocksource *cs)
  79 {
  80         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
  81 }
  82
  83 static struct clocksource clocksource_hpet = {
  84         .name           = "hpet",
  85         .rating         = 250,
  86         .read           = read_hpet,
  87         .mask           = CLOCKSOURCE_MASK(64),
  88         .mult           = 0, /* to be calculated */
  89         .shift          = 10,
  90         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  91 };
  92 static struct clocksource *hpet_clocksource;
  93 #endif
  94
  95 /* A lock for concurrent access by app and isr hpet activity. */
  96 static DEFINE_SPINLOCK(hpet_lock);
  97
  98 #define HPET_DEV_NAME   (7)
  99
 100 struct hpet_dev {
 101         struct hpets *hd_hpets;
 102         struct hpet __iomem *hd_hpet;
 103         struct hpet_timer __iomem *hd_timer;
 104         unsigned long hd_ireqfreq;
 105         unsigned long hd_irqdata;
 106         wait_queue_head_t hd_waitqueue;
 107         struct fasync_struct *hd_async_queue;
 108         unsigned int hd_flags;
 109         unsigned int hd_irq;
 110         unsigned int hd_hdwirq;
 111         char hd_name[HPET_DEV_NAME];
 112 };
 113
 114 struct hpets {
 115         struct hpets *hp_next;
 116         struct hpet __iomem *hp_hpet;
 117         unsigned long hp_hpet_phys;
 118         struct clocksource *hp_clocksource;
 119         unsigned long long hp_tick_freq;
 120         unsigned long hp_delta;
 121         unsigned int hp_ntimer;
 122         unsigned int hp_which;
 123         struct hpet_dev hp_dev[1];
 124 };
 125
 126 static struct hpets *hpets;
 127
 128 #define HPET_OPEN               0x0001
 129 #define HPET_IE                 0x0002  /* interrupt enabled */
 130 #define HPET_PERIODIC           0x0004
 131 #define HPET_SHARED_IRQ         0x0008
 132
 133
 134 #ifndef readq
 135 static inline unsigned long long readq(void __iomem *addr)
 136 {
 137         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 138 }
 139 #endif
 140
 141 #ifndef writeq
 142 static inline void writeq(unsigned long long v, void __iomem *addr)
 143 {
 144         writel(v & 0xffffffff, addr);
 145         writel(v >> 32, addr + 4);
 146 }
 147 #endif
 148
 149 static irqreturn_t hpet_interrupt(int irq, void *data)
 150 {
 151         struct hpet_dev *devp;
 152         unsigned long isr;
 153
 154         devp = data;
 155         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 156
 157         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 158             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 159                 return IRQ_NONE;
 160
 161         spin_lock(&hpet_lock);
 162         devp->hd_irqdata++;
 163
 164         /*
 165          * For non-periodic timers, increment the accumulator.
 166          * This has the effect of treating non-periodic like periodic.
 167          */
 168         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 169                 unsigned long m, t;
 170
 171                 t = devp->hd_ireqfreq;
 172                 m = read_counter(&devp->hd_timer->hpet_compare);
 173                 write_counter(t + m, &devp->hd_timer->hpet_compare);
 174         }
 175
 176         if (devp->hd_flags & HPET_SHARED_IRQ)
 177                 writel(isr, &devp->hd_hpet->hpet_isr);
 178         spin_unlock(&hpet_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_each_set_bit(irq, &v, HPET_MAX_IRQ) {
 222                 if (irq >= nr_irqs) {
 223                         irq = HPET_MAX_IRQ;
 224                         break;
 225                 }
 226
 227                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
 228                                         ACPI_ACTIVE_LOW);
 229                 if (gsi > 0)
 230                         break;
 231
 232                 /* FIXME: Setup interrupt source table */
 233         }
 234
 235         if (irq < HPET_MAX_IRQ) {
 236                 spin_lock_irq(&hpet_lock);
 237                 v = readl(&timer->hpet_config);
 238                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
 239                 writel(v, &timer->hpet_config);
 240                 devp->hd_hdwirq = gsi;
 241                 spin_unlock_irq(&hpet_lock);
 242         }
 243         return;
 244 }
 245
 246 static int hpet_open(struct inode *inode, struct file *file)
 247 {
 248         struct hpet_dev *devp;
 249         struct hpets *hpetp;
 250         int i;
 251
 252         if (file->f_mode & FMODE_WRITE)
 253                 return -EINVAL;
 254
 255         mutex_lock(&hpet_mutex);
 256         spin_lock_irq(&hpet_lock);
 257
 258         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 259                 for (i = 0; i < hpetp->hp_ntimer; i++)
 260                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
 261                                 continue;
 262                         else {
 263                                 devp = &hpetp->hp_dev[i];
 264                                 break;
 265                         }
 266
 267         if (!devp) {
 268                 spin_unlock_irq(&hpet_lock);
 269                 mutex_unlock(&hpet_mutex);
 270                 return -EBUSY;
 271         }
 272
 273         file->private_data = devp;
 274         devp->hd_irqdata = 0;
 275         devp->hd_flags |= HPET_OPEN;
 276         spin_unlock_irq(&hpet_lock);
 277         mutex_unlock(&hpet_mutex);
 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         file->private_data = NULL;
 431         return 0;
 432 }
 433
 434 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 435 {
 436         struct hpet_timer __iomem *timer;
 437         struct hpet __iomem *hpet;
 438         struct hpets *hpetp;
 439         int irq;
 440         unsigned long g, v, t, m;
 441         unsigned long flags, isr;
 442
 443         timer = devp->hd_timer;
 444         hpet = devp->hd_hpet;
 445         hpetp = devp->hd_hpets;
 446
 447         if (!devp->hd_ireqfreq)
 448                 return -EIO;
 449
 450         spin_lock_irq(&hpet_lock);
 451
 452         if (devp->hd_flags & HPET_IE) {
 453                 spin_unlock_irq(&hpet_lock);
 454                 return -EBUSY;
 455         }
 456
 457         devp->hd_flags |= HPET_IE;
 458
 459         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 460                 devp->hd_flags |= HPET_SHARED_IRQ;
 461         spin_unlock_irq(&hpet_lock);
 462
 463         irq = devp->hd_hdwirq;
 464
 465         if (irq) {
 466                 unsigned long irq_flags;
 467
 468                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 469                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 470                                                 ? IRQF_SHARED : IRQF_DISABLED;
 471                 if (request_irq(irq, hpet_interrupt, irq_flags,
 472                                 devp->hd_name, (void *)devp)) {
 473                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 474                         irq = 0;
 475                 }
 476         }
 477
 478         if (irq == 0) {
 479                 spin_lock_irq(&hpet_lock);
 480                 devp->hd_flags ^= HPET_IE;
 481                 spin_unlock_irq(&hpet_lock);
 482                 return -EIO;
 483         }
 484
 485         devp->hd_irq = irq;
 486         t = devp->hd_ireqfreq;
 487         v = readq(&timer->hpet_config);
 488
 489         /* 64-bit comparators are not yet supported through the ioctls,
 490          * so force this into 32-bit mode if it supports both modes
 491          */
 492         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
 493
 494         if (devp->hd_flags & HPET_PERIODIC) {
 495                 g |= Tn_TYPE_CNF_MASK;
 496                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
 497                 writeq(v, &timer->hpet_config);
 498                 local_irq_save(flags);
 499
 500                 /*
 501                  * NOTE: First we modify the hidden accumulator
 502                  * register supported by periodic-capable comparators.
 503                  * We never want to modify the (single) counter; that
 504                  * would affect all the comparators. The value written
 505                  * is the counter value when the first interrupt is due.
 506                  */
 507                 m = read_counter(&hpet->hpet_mc);
 508                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 509                 /*
 510                  * Then we modify the comparator, indicating the period
 511                  * for subsequent interrupt.
 512                  */
 513                 write_counter(t, &timer->hpet_compare);
 514         } else {
 515                 local_irq_save(flags);
 516                 m = read_counter(&hpet->hpet_mc);
 517                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 518         }
 519
 520         if (devp->hd_flags & HPET_SHARED_IRQ) {
 521                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 522                 writel(isr, &hpet->hpet_isr);
 523         }
 524         writeq(g, &timer->hpet_config);
 525         local_irq_restore(flags);
 526
 527         return 0;
 528 }
 529
 530 /* converts Hz to number of timer ticks */
 531 static inline unsigned long hpet_time_div(struct hpets *hpets,
 532                                           unsigned long dis)
 533 {
 534         unsigned long long m;
 535
 536         m = hpets->hp_tick_freq + (dis >> 1);
 537         do_div(m, dis);
 538         return (unsigned long)m;
 539 }
 540
 541 static int
 542 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
 543                   struct hpet_info *info)
 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                         if (devp->hd_ireqfreq)
 585                                 info->hi_ireqfreq =
 586                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 587                         else
 588                                 info->hi_ireqfreq = 0;
 589                         info->hi_flags =
 590                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 591                         info->hi_hpet = hpetp->hp_which;
 592                         info->hi_timer = devp - hpetp->hp_dev;
 593                         break;
 594                 }
 595         case HPET_EPI:
 596                 v = readq(&timer->hpet_config);
 597                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 598                         err = -ENXIO;
 599                         break;
 600                 }
 601                 devp->hd_flags |= HPET_PERIODIC;
 602                 break;
 603         case HPET_DPI:
 604                 v = readq(&timer->hpet_config);
 605                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 606                         err = -ENXIO;
 607                         break;
 608                 }
 609                 if (devp->hd_flags & HPET_PERIODIC &&
 610                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 611                         v = readq(&timer->hpet_config);
 612                         v ^= Tn_TYPE_CNF_MASK;
 613                         writeq(v, &timer->hpet_config);
 614                 }
 615                 devp->hd_flags &= ~HPET_PERIODIC;
 616                 break;
 617         case HPET_IRQFREQ:
 618                 if ((arg > hpet_max_freq) &&
 619                     !capable(CAP_SYS_RESOURCE)) {
 620                         err = -EACCES;
 621                         break;
 622                 }
 623
 624                 if (!arg) {
 625                         err = -EINVAL;
 626                         break;
 627                 }
 628
 629                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 630         }
 631
 632         return err;
 633 }
 634
 635 static long
 636 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 637 {
 638         struct hpet_info info;
 639         int err;
 640
 641         mutex_lock(&hpet_mutex);
 642         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
 643         mutex_unlock(&hpet_mutex);
 644
 645         if ((cmd == HPET_INFO) && !err &&
 646             (copy_to_user((void __user *)arg, &info, sizeof(info))))
 647                 err = -EFAULT;
 648
 649         return err;
 650 }
 651
 652 #ifdef CONFIG_COMPAT
 653 struct compat_hpet_info {
 654         compat_ulong_t hi_ireqfreq;     /* Hz */
 655         compat_ulong_t hi_flags;        /* information */
 656         unsigned short hi_hpet;
 657         unsigned short hi_timer;
 658 };
 659
 660 static long
 661 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 662 {
 663         struct hpet_info info;
 664         int err;
 665
 666         mutex_lock(&hpet_mutex);
 667         err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
 668         mutex_unlock(&hpet_mutex);
 669
 670         if ((cmd == HPET_INFO) && !err) {
 671                 struct compat_hpet_info __user *u = compat_ptr(arg);
 672                 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
 673                     put_user(info.hi_flags, &u->hi_flags) ||
 674                     put_user(info.hi_hpet, &u->hi_hpet) ||
 675                     put_user(info.hi_timer, &u->hi_timer))
 676                         err = -EFAULT;
 677         }
 678
 679         return err;
 680 }
 681 #endif
 682
 683 static const struct file_operations hpet_fops = {
 684         .owner = THIS_MODULE,
 685         .llseek = no_llseek,
 686         .read = hpet_read,
 687         .poll = hpet_poll,
 688         .unlocked_ioctl = hpet_ioctl,
 689 #ifdef CONFIG_COMPAT
 690         .compat_ioctl = hpet_compat_ioctl,
 691 #endif
 692         .open = hpet_open,
 693         .release = hpet_release,
 694         .fasync = hpet_fasync,
 695         .mmap = hpet_mmap,
 696 };
 697
 698 static int hpet_is_known(struct hpet_data *hdp)
 699 {
 700         struct hpets *hpetp;
 701
 702         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 703                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 704                         return 1;
 705
 706         return 0;
 707 }
 708
 709 static ctl_table hpet_table[] = {
 710         {
 711          .procname = "max-user-freq",
 712          .data = &hpet_max_freq,
 713          .maxlen = sizeof(int),
 714          .mode = 0644,
 715          .proc_handler = proc_dointvec,
 716          },
 717         {}
 718 };
 719
 720 static ctl_table hpet_root[] = {
 721         {
 722          .procname = "hpet",
 723          .maxlen = 0,
 724          .mode = 0555,
 725          .child = hpet_table,
 726          },
 727         {}
 728 };
 729
 730 static ctl_table dev_root[] = {
 731         {
 732          .procname = "dev",
 733          .maxlen = 0,
 734          .mode = 0555,
 735          .child = hpet_root,
 736          },
 737         {}
 738 };
 739
 740 static struct ctl_table_header *sysctl_header;
 741
 742 /*
 743  * Adjustment for when arming the timer with
 744  * initial conditions.  That is, main counter
 745  * ticks expired before interrupts are enabled.
 746  */
 747 #define TICK_CALIBRATE  (1000UL)
 748
 749 static unsigned long __hpet_calibrate(struct hpets *hpetp)
 750 {
 751         struct hpet_timer __iomem *timer = NULL;
 752         unsigned long t, m, count, i, flags, start;
 753         struct hpet_dev *devp;
 754         int j;
 755         struct hpet __iomem *hpet;
 756
 757         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 758                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 759                         timer = devp->hd_timer;
 760                         break;
 761                 }
 762
 763         if (!timer)
 764                 return 0;
 765
 766         hpet = hpetp->hp_hpet;
 767         t = read_counter(&timer->hpet_compare);
 768
 769         i = 0;
 770         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 771
 772         local_irq_save(flags);
 773
 774         start = read_counter(&hpet->hpet_mc);
 775
 776         do {
 777                 m = read_counter(&hpet->hpet_mc);
 778                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 779         } while (i++, (m - start) < count);
 780
 781         local_irq_restore(flags);
 782
 783         return (m - start) / i;
 784 }
 785
 786 static unsigned long hpet_calibrate(struct hpets *hpetp)
 787 {
 788         unsigned long ret = -1;
 789         unsigned long tmp;
 790
 791         /*
 792          * Try to calibrate until return value becomes stable small value.
 793          * If SMI interruption occurs in calibration loop, the return value
 794          * will be big. This avoids its impact.
 795          */
 796         for ( ; ; ) {
 797                 tmp = __hpet_calibrate(hpetp);
 798                 if (ret <= tmp)
 799                         break;
 800                 ret = tmp;
 801         }
 802
 803         return ret;
 804 }
 805
 806 int hpet_alloc(struct hpet_data *hdp)
 807 {
 808         u64 cap, mcfg;
 809         struct hpet_dev *devp;
 810         u32 i, ntimer;
 811         struct hpets *hpetp;
 812         size_t siz;
 813         struct hpet __iomem *hpet;
 814         static struct hpets *last = NULL;
 815         unsigned long period;
 816         unsigned long long temp;
 817         u32 remainder;
 818
 819         /*
 820          * hpet_alloc can be called by platform dependent code.
 821          * If platform dependent code has allocated the hpet that
 822          * ACPI has also reported, then we catch it here.
 823          */
 824         if (hpet_is_known(hdp)) {
 825                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 826                         __func__);
 827                 return 0;
 828         }
 829
 830         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 831                                       sizeof(struct hpet_dev));
 832
 833         hpetp = kzalloc(siz, GFP_KERNEL);
 834
 835         if (!hpetp)
 836                 return -ENOMEM;
 837
 838         hpetp->hp_which = hpet_nhpet++;
 839         hpetp->hp_hpet = hdp->hd_address;
 840         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 841
 842         hpetp->hp_ntimer = hdp->hd_nirqs;
 843
 844         for (i = 0; i < hdp->hd_nirqs; i++)
 845                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 846
 847         hpet = hpetp->hp_hpet;
 848
 849         cap = readq(&hpet->hpet_cap);
 850
 851         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 852
 853         if (hpetp->hp_ntimer != ntimer) {
 854                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 855                        " with number of timers\n");
 856                 kfree(hpetp);
 857                 return -ENODEV;
 858         }
 859
 860         if (last)
 861                 last->hp_next = hpetp;
 862         else
 863                 hpets = hpetp;
 864
 865         last = hpetp;
 866
 867         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 868                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 869         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 870         temp += period >> 1; /* round */
 871         do_div(temp, period);
 872         hpetp->hp_tick_freq = temp; /* ticks per second */
 873
 874         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 875                 hpetp->hp_which, hdp->hd_phys_address,
 876                 hpetp->hp_ntimer > 1 ? "s" : "");
 877         for (i = 0; i < hpetp->hp_ntimer; i++)
 878                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 879         printk("\n");
 880
 881         temp = hpetp->hp_tick_freq;
 882         remainder = do_div(temp, 1000000);
 883         printk(KERN_INFO
 884                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
 885                 hpetp->hp_which, hpetp->hp_ntimer,
 886                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
 887                 (unsigned) temp, remainder);
 888
 889         mcfg = readq(&hpet->hpet_config);
 890         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 891                 write_counter(0L, &hpet->hpet_mc);
 892                 mcfg |= HPET_ENABLE_CNF_MASK;
 893                 writeq(mcfg, &hpet->hpet_config);
 894         }
 895
 896         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 897                 struct hpet_timer __iomem *timer;
 898
 899                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 900
 901                 devp->hd_hpets = hpetp;
 902                 devp->hd_hpet = hpet;
 903                 devp->hd_timer = timer;
 904
 905                 /*
 906                  * If the timer was reserved by platform code,
 907                  * then make timer unavailable for opens.
 908                  */
 909                 if (hdp->hd_state & (1 << i)) {
 910                         devp->hd_flags = HPET_OPEN;
 911                         continue;
 912                 }
 913
 914                 init_waitqueue_head(&devp->hd_waitqueue);
 915         }
 916
 917         hpetp->hp_delta = hpet_calibrate(hpetp);
 918
 919 /* This clocksource driver currently only works on ia64 */
 920 #ifdef CONFIG_IA64
 921         if (!hpet_clocksource) {
 922                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
 923                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
 924                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
 925                                                 clocksource_hpet.shift);
 926                 clocksource_register(&clocksource_hpet);
 927                 hpetp->hp_clocksource = &clocksource_hpet;
 928                 hpet_clocksource = &clocksource_hpet;
 929         }
 930 #endif
 931
 932         return 0;
 933 }
 934
 935 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 936 {
 937         struct hpet_data *hdp;
 938         acpi_status status;
 939         struct acpi_resource_address64 addr;
 940
 941         hdp = data;
 942
 943         status = acpi_resource_to_address64(res, &addr);
 944
 945         if (ACPI_SUCCESS(status)) {
 946                 hdp->hd_phys_address = addr.minimum;
 947                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 948
 949                 if (hpet_is_known(hdp)) {
 950                         iounmap(hdp->hd_address);
 951                         return AE_ALREADY_EXISTS;
 952                 }
 953         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 954                 struct acpi_resource_fixed_memory32 *fixmem32;
 955
 956                 fixmem32 = &res->data.fixed_memory32;
 957                 if (!fixmem32)
 958                         return AE_NO_MEMORY;
 959
 960                 hdp->hd_phys_address = fixmem32->address;
 961                 hdp->hd_address = ioremap(fixmem32->address,
 962                                                 HPET_RANGE_SIZE);
 963
 964                 if (hpet_is_known(hdp)) {
 965                         iounmap(hdp->hd_address);
 966                         return AE_ALREADY_EXISTS;
 967                 }
 968         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 969                 struct acpi_resource_extended_irq *irqp;
 970                 int i, irq;
 971
 972                 irqp = &res->data.extended_irq;
 973
 974                 for (i = 0; i < irqp->interrupt_count; i++) {
 975                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
 976                                       irqp->triggering, irqp->polarity);
 977                         if (irq < 0)
 978                                 return AE_ERROR;
 979
 980                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 981                         hdp->hd_nirqs++;
 982                 }
 983         }
 984
 985         return AE_OK;
 986 }
 987
 988 static int hpet_acpi_add(struct acpi_device *device)
 989 {
 990         acpi_status result;
 991         struct hpet_data data;
 992
 993         memset(&data, 0, sizeof(data));
 994
 995         result =
 996             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 997                                 hpet_resources, &data);
 998
 999         if (ACPI_FAILURE(result))
1000                 return -ENODEV;
1001
1002         if (!data.hd_address || !data.hd_nirqs) {
1003                 printk("%s: no address or irqs in _CRS\n", __func__);
1004                 return -ENODEV;
1005         }
1006
1007         return hpet_alloc(&data);
1008 }
1009
1010 static int hpet_acpi_remove(struct acpi_device *device, int type)
1011 {
1012         /* XXX need to unregister clocksource, dealloc mem, etc */
1013         return -EINVAL;
1014 }
1015
1016 static const struct acpi_device_id hpet_device_ids[] = {
1017         {"PNP0103", 0},
1018         {"", 0},
1019 };
1020 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
1021
1022 static struct acpi_driver hpet_acpi_driver = {
1023         .name = "hpet",
1024         .ids = hpet_device_ids,
1025         .ops = {
1026                 .add = hpet_acpi_add,
1027                 .remove = hpet_acpi_remove,
1028                 },
1029 };
1030
1031 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
1032
1033 static int __init hpet_init(void)
1034 {
1035         int result;
1036
1037         result = misc_register(&hpet_misc);
1038         if (result < 0)
1039                 return -ENODEV;
1040
1041         sysctl_header = register_sysctl_table(dev_root);
1042
1043         result = acpi_bus_register_driver(&hpet_acpi_driver);
1044         if (result < 0) {
1045                 if (sysctl_header)
1046                         unregister_sysctl_table(sysctl_header);
1047                 misc_deregister(&hpet_misc);
1048                 return result;
1049         }
1050
1051         return 0;
1052 }
1053
1054 static void __exit hpet_exit(void)
1055 {
1056         acpi_bus_unregister_driver(&hpet_acpi_driver);
1057
1058         if (sysctl_header)
1059                 unregister_sysctl_table(sysctl_header);
1060         misc_deregister(&hpet_misc);
1061
1062         return;
1063 }
1064
1065 module_init(hpet_init);
1066 module_exit(hpet_exit);
1067 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1068 MODULE_LICENSE("GPL");