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

   1 /*
   2  * Intel & MS High Precision Event Timer Implementation.
   3  *
   4  * Copyright (C) 2003 Intel Corporation
   5  *      Venki Pallipadi
   6  * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
   7  *      Bob Picco <robert.picco@hp.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/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/clocksource.h>
  34 #include <linux/slab.h>
  35
  36 #include <asm/current.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/system.h>
  39 #include <asm/io.h>
  40 #include <asm/irq.h>
  41 #include <asm/div64.h>
  42
  43 #include <linux/acpi.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <linux/hpet.h>
  46
  47 /*
  48  * The High Precision Event Timer driver.
  49  * This driver is closely modelled after the rtc.c driver.
  50  * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
  51  */
  52 #define HPET_USER_FREQ  (64)
  53 #define HPET_DRIFT      (500)
  54
  55 #define HPET_RANGE_SIZE         1024    /* from HPET spec */
  56
  57
  58 /* WARNING -- don't get confused.  These macros are never used
  59  * to write the (single) counter, and rarely to read it.
  60  * They're badly named; to fix, someday.
  61  */
  62 #if BITS_PER_LONG == 64
  63 #define write_counter(V, MC)    writeq(V, MC)
  64 #define read_counter(MC)        readq(MC)
  65 #else
  66 #define write_counter(V, MC)    writel(V, MC)
  67 #define read_counter(MC)        readl(MC)
  68 #endif
  69
  70 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  71
  72 /* This clocksource driver currently only works on ia64 */
  73 #ifdef CONFIG_IA64
  74 static void __iomem *hpet_mctr;
  75
  76 static cycle_t read_hpet(struct clocksource *cs)
  77 {
  78         return (cycle_t)read_counter((void __iomem *)hpet_mctr);
  79 }
  80
  81 static struct clocksource clocksource_hpet = {
  82         .name           = "hpet",
  83         .rating         = 250,
  84         .read           = read_hpet,
  85         .mask           = CLOCKSOURCE_MASK(64),
  86         .mult           = 0, /* to be calculated */
  87         .shift          = 10,
  88         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
  89 };
  90 static struct clocksource *hpet_clocksource;
  91 #endif
  92
  93 /* A lock for concurrent access by app and isr hpet activity. */
  94 static DEFINE_SPINLOCK(hpet_lock);
  95
  96 #define HPET_DEV_NAME   (7)
  97
  98 struct hpet_dev {
  99         struct hpets *hd_hpets;
 100         struct hpet __iomem *hd_hpet;
 101         struct hpet_timer __iomem *hd_timer;
 102         unsigned long hd_ireqfreq;
 103         unsigned long hd_irqdata;
 104         wait_queue_head_t hd_waitqueue;
 105         struct fasync_struct *hd_async_queue;
 106         unsigned int hd_flags;
 107         unsigned int hd_irq;
 108         unsigned int hd_hdwirq;
 109         char hd_name[HPET_DEV_NAME];
 110 };
 111
 112 struct hpets {
 113         struct hpets *hp_next;
 114         struct hpet __iomem *hp_hpet;
 115         unsigned long hp_hpet_phys;
 116         struct clocksource *hp_clocksource;
 117         unsigned long long hp_tick_freq;
 118         unsigned long hp_delta;
 119         unsigned int hp_ntimer;
 120         unsigned int hp_which;
 121         struct hpet_dev hp_dev[1];
 122 };
 123
 124 static struct hpets *hpets;
 125
 126 #define HPET_OPEN               0x0001
 127 #define HPET_IE                 0x0002  /* interrupt enabled */
 128 #define HPET_PERIODIC           0x0004
 129 #define HPET_SHARED_IRQ         0x0008
 130
 131
 132 #ifndef readq
 133 static inline unsigned long long readq(void __iomem *addr)
 134 {
 135         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 136 }
 137 #endif
 138
 139 #ifndef writeq
 140 static inline void writeq(unsigned long long v, void __iomem *addr)
 141 {
 142         writel(v & 0xffffffff, addr);
 143         writel(v >> 32, addr + 4);
 144 }
 145 #endif
 146
 147 static irqreturn_t hpet_interrupt(int irq, void *data)
 148 {
 149         struct hpet_dev *devp;
 150         unsigned long isr;
 151
 152         devp = data;
 153         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 154
 155         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 156             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 157                 return IRQ_NONE;
 158
 159         spin_lock(&hpet_lock);
 160         devp->hd_irqdata++;
 161
 162         /*
 163          * For non-periodic timers, increment the accumulator.
 164          * This has the effect of treating non-periodic like periodic.
 165          */
 166         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 167                 unsigned long m, t;
 168
 169                 t = devp->hd_ireqfreq;
 170                 m = read_counter(&devp->hd_timer->hpet_compare);
 171                 write_counter(t + m, &devp->hd_timer->hpet_compare);
 172         }
 173
 174         if (devp->hd_flags & HPET_SHARED_IRQ)
 175                 writel(isr, &devp->hd_hpet->hpet_isr);
 176         spin_unlock(&hpet_lock);
 177
 178         wake_up_interruptible(&devp->hd_waitqueue);
 179
 180         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 181
 182         return IRQ_HANDLED;
 183 }
 184
 185 static void hpet_timer_set_irq(struct hpet_dev *devp)
 186 {
 187         unsigned long v;
 188         int irq, gsi;
 189         struct hpet_timer __iomem *timer;
 190
 191         spin_lock_irq(&hpet_lock);
 192         if (devp->hd_hdwirq) {
 193                 spin_unlock_irq(&hpet_lock);
 194                 return;
 195         }
 196
 197         timer = devp->hd_timer;
 198
 199         /* we prefer level triggered mode */
 200         v = readl(&timer->hpet_config);
 201         if (!(v & Tn_INT_TYPE_CNF_MASK)) {
 202                 v |= Tn_INT_TYPE_CNF_MASK;
 203                 writel(v, &timer->hpet_config);
 204         }
 205         spin_unlock_irq(&hpet_lock);
 206
 207         v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
 208                                  Tn_INT_ROUTE_CAP_SHIFT;
 209
 210         /*
 211          * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
 212          * legacy device. In IO APIC mode, we skip all the legacy IRQS.
 213          */
 214         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 215                 v &= ~0xf3df;
 216         else
 217                 v &= ~0xffff;
 218
 219         for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
 220                 if (irq >= nr_irqs) {
 221                         irq = HPET_MAX_IRQ;
 222                         break;
 223                 }
 224
 225                 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
 226                                         ACPI_ACTIVE_LOW);
 227                 if (gsi > 0)
 228                         break;
 229
 230                 /* FIXME: Setup interrupt source table */
 231         }
 232
 233         if (irq < HPET_MAX_IRQ) {
 234                 spin_lock_irq(&hpet_lock);
 235                 v = readl(&timer->hpet_config);
 236                 v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
 237                 writel(v, &timer->hpet_config);
 238                 devp->hd_hdwirq = gsi;
 239                 spin_unlock_irq(&hpet_lock);
 240         }
 241         return;
 242 }
 243
 244 static int hpet_open(struct inode *inode, struct file *file)
 245 {
 246         struct hpet_dev *devp;
 247         struct hpets *hpetp;
 248         int i;
 249
 250         if (file->f_mode & FMODE_WRITE)
 251                 return -EINVAL;
 252
 253         lock_kernel();
 254         spin_lock_irq(&hpet_lock);
 255
 256         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 257                 for (i = 0; i < hpetp->hp_ntimer; i++)
 258                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN)
 259                                 continue;
 260                         else {
 261                                 devp = &hpetp->hp_dev[i];
 262                                 break;
 263                         }
 264
 265         if (!devp) {
 266                 spin_unlock_irq(&hpet_lock);
 267                 unlock_kernel();
 268                 return -EBUSY;
 269         }
 270
 271         file->private_data = devp;
 272         devp->hd_irqdata = 0;
 273         devp->hd_flags |= HPET_OPEN;
 274         spin_unlock_irq(&hpet_lock);
 275         unlock_kernel();
 276
 277         hpet_timer_set_irq(devp);
 278
 279         return 0;
 280 }
 281
 282 static ssize_t
 283 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 284 {
 285         DECLARE_WAITQUEUE(wait, current);
 286         unsigned long data;
 287         ssize_t retval;
 288         struct hpet_dev *devp;
 289
 290         devp = file->private_data;
 291         if (!devp->hd_ireqfreq)
 292                 return -EIO;
 293
 294         if (count < sizeof(unsigned long))
 295                 return -EINVAL;
 296
 297         add_wait_queue(&devp->hd_waitqueue, &wait);
 298
 299         for ( ; ; ) {
 300                 set_current_state(TASK_INTERRUPTIBLE);
 301
 302                 spin_lock_irq(&hpet_lock);
 303                 data = devp->hd_irqdata;
 304                 devp->hd_irqdata = 0;
 305                 spin_unlock_irq(&hpet_lock);
 306
 307                 if (data)
 308                         break;
 309                 else if (file->f_flags & O_NONBLOCK) {
 310                         retval = -EAGAIN;
 311                         goto out;
 312                 } else if (signal_pending(current)) {
 313                         retval = -ERESTARTSYS;
 314                         goto out;
 315                 }
 316                 schedule();
 317         }
 318
 319         retval = put_user(data, (unsigned long __user *)buf);
 320         if (!retval)
 321                 retval = sizeof(unsigned long);
 322 out:
 323         __set_current_state(TASK_RUNNING);
 324         remove_wait_queue(&devp->hd_waitqueue, &wait);
 325
 326         return retval;
 327 }
 328
 329 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 330 {
 331         unsigned long v;
 332         struct hpet_dev *devp;
 333
 334         devp = file->private_data;
 335
 336         if (!devp->hd_ireqfreq)
 337                 return 0;
 338
 339         poll_wait(file, &devp->hd_waitqueue, wait);
 340
 341         spin_lock_irq(&hpet_lock);
 342         v = devp->hd_irqdata;
 343         spin_unlock_irq(&hpet_lock);
 344
 345         if (v != 0)
 346                 return POLLIN | POLLRDNORM;
 347
 348         return 0;
 349 }
 350
 351 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 352 {
 353 #ifdef  CONFIG_HPET_MMAP
 354         struct hpet_dev *devp;
 355         unsigned long addr;
 356
 357         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 358                 return -EINVAL;
 359
 360         devp = file->private_data;
 361         addr = devp->hd_hpets->hp_hpet_phys;
 362
 363         if (addr & (PAGE_SIZE - 1))
 364                 return -ENOSYS;
 365
 366         vma->vm_flags |= VM_IO;
 367         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 368
 369         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 370                                         PAGE_SIZE, vma->vm_page_prot)) {
 371                 printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
 372                         __func__);
 373                 return -EAGAIN;
 374         }
 375
 376         return 0;
 377 #else
 378         return -ENOSYS;
 379 #endif
 380 }
 381
 382 static int hpet_fasync(int fd, struct file *file, int on)
 383 {
 384         struct hpet_dev *devp;
 385
 386         devp = file->private_data;
 387
 388         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 389                 return 0;
 390         else
 391                 return -EIO;
 392 }
 393
 394 static int hpet_release(struct inode *inode, struct file *file)
 395 {
 396         struct hpet_dev *devp;
 397         struct hpet_timer __iomem *timer;
 398         int irq = 0;
 399
 400         devp = file->private_data;
 401         timer = devp->hd_timer;
 402
 403         spin_lock_irq(&hpet_lock);
 404
 405         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 406                &timer->hpet_config);
 407
 408         irq = devp->hd_irq;
 409         devp->hd_irq = 0;
 410
 411         devp->hd_ireqfreq = 0;
 412
 413         if (devp->hd_flags & HPET_PERIODIC
 414             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 415                 unsigned long v;
 416
 417                 v = readq(&timer->hpet_config);
 418                 v ^= Tn_TYPE_CNF_MASK;
 419                 writeq(v, &timer->hpet_config);
 420         }
 421
 422         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 423         spin_unlock_irq(&hpet_lock);
 424
 425         if (irq)
 426                 free_irq(irq, devp);
 427
 428         file->private_data = NULL;
 429         return 0;
 430 }
 431
 432 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 433
 434 static int
 435 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 436            unsigned long arg)
 437 {
 438         struct hpet_dev *devp;
 439
 440         devp = file->private_data;
 441         return hpet_ioctl_common(devp, cmd, arg, 0);
 442 }
 443
 444 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 445 {
 446         struct hpet_timer __iomem *timer;
 447         struct hpet __iomem *hpet;
 448         struct hpets *hpetp;
 449         int irq;
 450         unsigned long g, v, t, m;
 451         unsigned long flags, isr;
 452
 453         timer = devp->hd_timer;
 454         hpet = devp->hd_hpet;
 455         hpetp = devp->hd_hpets;
 456
 457         if (!devp->hd_ireqfreq)
 458                 return -EIO;
 459
 460         spin_lock_irq(&hpet_lock);
 461
 462         if (devp->hd_flags & HPET_IE) {
 463                 spin_unlock_irq(&hpet_lock);
 464                 return -EBUSY;
 465         }
 466
 467         devp->hd_flags |= HPET_IE;
 468
 469         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 470                 devp->hd_flags |= HPET_SHARED_IRQ;
 471         spin_unlock_irq(&hpet_lock);
 472
 473         irq = devp->hd_hdwirq;
 474
 475         if (irq) {
 476                 unsigned long irq_flags;
 477
 478                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 479                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 480                                                 ? IRQF_SHARED : IRQF_DISABLED;
 481                 if (request_irq(irq, hpet_interrupt, irq_flags,
 482                                 devp->hd_name, (void *)devp)) {
 483                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 484                         irq = 0;
 485                 }
 486         }
 487
 488         if (irq == 0) {
 489                 spin_lock_irq(&hpet_lock);
 490                 devp->hd_flags ^= HPET_IE;
 491                 spin_unlock_irq(&hpet_lock);
 492                 return -EIO;
 493         }
 494
 495         devp->hd_irq = irq;
 496         t = devp->hd_ireqfreq;
 497         v = readq(&timer->hpet_config);
 498
 499         /* 64-bit comparators are not yet supported through the ioctls,
 500          * so force this into 32-bit mode if it supports both modes
 501          */
 502         g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
 503
 504         if (devp->hd_flags & HPET_PERIODIC) {
 505                 g |= Tn_TYPE_CNF_MASK;
 506                 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
 507                 writeq(v, &timer->hpet_config);
 508                 local_irq_save(flags);
 509
 510                 /*
 511                  * NOTE: First we modify the hidden accumulator
 512                  * register supported by periodic-capable comparators.
 513                  * We never want to modify the (single) counter; that
 514                  * would affect all the comparators. The value written
 515                  * is the counter value when the first interrupt is due.
 516                  */
 517                 m = read_counter(&hpet->hpet_mc);
 518                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 519                 /*
 520                  * Then we modify the comparator, indicating the period
 521                  * for subsequent interrupt.
 522                  */
 523                 write_counter(t, &timer->hpet_compare);
 524         } else {
 525                 local_irq_save(flags);
 526                 m = read_counter(&hpet->hpet_mc);
 527                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 528         }
 529
 530         if (devp->hd_flags & HPET_SHARED_IRQ) {
 531                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 532                 writel(isr, &hpet->hpet_isr);
 533         }
 534         writeq(g, &timer->hpet_config);
 535         local_irq_restore(flags);
 536
 537         return 0;
 538 }
 539
 540 /* converts Hz to number of timer ticks */
 541 static inline unsigned long hpet_time_div(struct hpets *hpets,
 542                                           unsigned long dis)
 543 {
 544         unsigned long long m;
 545
 546         m = hpets->hp_tick_freq + (dis >> 1);
 547         do_div(m, dis);
 548         return (unsigned long)m;
 549 }
 550
 551 static int
 552 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 553 {
 554         struct hpet_timer __iomem *timer;
 555         struct hpet __iomem *hpet;
 556         struct hpets *hpetp;
 557         int err;
 558         unsigned long v;
 559
 560         switch (cmd) {
 561         case HPET_IE_OFF:
 562         case HPET_INFO:
 563         case HPET_EPI:
 564         case HPET_DPI:
 565         case HPET_IRQFREQ:
 566                 timer = devp->hd_timer;
 567                 hpet = devp->hd_hpet;
 568                 hpetp = devp->hd_hpets;
 569                 break;
 570         case HPET_IE_ON:
 571                 return hpet_ioctl_ieon(devp);
 572         default:
 573                 return -EINVAL;
 574         }
 575
 576         err = 0;
 577
 578         switch (cmd) {
 579         case HPET_IE_OFF:
 580                 if ((devp->hd_flags & HPET_IE) == 0)
 581                         break;
 582                 v = readq(&timer->hpet_config);
 583                 v &= ~Tn_INT_ENB_CNF_MASK;
 584                 writeq(v, &timer->hpet_config);
 585                 if (devp->hd_irq) {
 586                         free_irq(devp->hd_irq, devp);
 587                         devp->hd_irq = 0;
 588                 }
 589                 devp->hd_flags ^= HPET_IE;
 590                 break;
 591         case HPET_INFO:
 592                 {
 593                         struct hpet_info info;
 594
 595                         if (devp->hd_ireqfreq)
 596                                 info.hi_ireqfreq =
 597                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 598                         else
 599                                 info.hi_ireqfreq = 0;
 600                         info.hi_flags =
 601                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 602                         info.hi_hpet = hpetp->hp_which;
 603                         info.hi_timer = devp - hpetp->hp_dev;
 604                         if (kernel)
 605                                 memcpy((void *)arg, &info, sizeof(info));
 606                         else
 607                                 if (copy_to_user((void __user *)arg, &info,
 608                                                  sizeof(info)))
 609                                         err = -EFAULT;
 610                         break;
 611                 }
 612         case HPET_EPI:
 613                 v = readq(&timer->hpet_config);
 614                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 615                         err = -ENXIO;
 616                         break;
 617                 }
 618                 devp->hd_flags |= HPET_PERIODIC;
 619                 break;
 620         case HPET_DPI:
 621                 v = readq(&timer->hpet_config);
 622                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 623                         err = -ENXIO;
 624                         break;
 625                 }
 626                 if (devp->hd_flags & HPET_PERIODIC &&
 627                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 628                         v = readq(&timer->hpet_config);
 629                         v ^= Tn_TYPE_CNF_MASK;
 630                         writeq(v, &timer->hpet_config);
 631                 }
 632                 devp->hd_flags &= ~HPET_PERIODIC;
 633                 break;
 634         case HPET_IRQFREQ:
 635                 if (!kernel && (arg > hpet_max_freq) &&
 636                     !capable(CAP_SYS_RESOURCE)) {
 637                         err = -EACCES;
 638                         break;
 639                 }
 640
 641                 if (!arg) {
 642                         err = -EINVAL;
 643                         break;
 644                 }
 645
 646                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 647         }
 648
 649         return err;
 650 }
 651
 652 static const struct file_operations hpet_fops = {
 653         .owner = THIS_MODULE,
 654         .llseek = no_llseek,
 655         .read = hpet_read,
 656         .poll = hpet_poll,
 657         .ioctl = hpet_ioctl,
 658         .open = hpet_open,
 659         .release = hpet_release,
 660         .fasync = hpet_fasync,
 661         .mmap = hpet_mmap,
 662 };
 663
 664 static int hpet_is_known(struct hpet_data *hdp)
 665 {
 666         struct hpets *hpetp;
 667
 668         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 669                 if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
 670                         return 1;
 671
 672         return 0;
 673 }
 674
 675 static ctl_table hpet_table[] = {
 676         {
 677          .procname = "max-user-freq",
 678          .data = &hpet_max_freq,
 679          .maxlen = sizeof(int),
 680          .mode = 0644,
 681          .proc_handler = proc_dointvec,
 682          },
 683         {}
 684 };
 685
 686 static ctl_table hpet_root[] = {
 687         {
 688          .procname = "hpet",
 689          .maxlen = 0,
 690          .mode = 0555,
 691          .child = hpet_table,
 692          },
 693         {}
 694 };
 695
 696 static ctl_table dev_root[] = {
 697         {
 698          .procname = "dev",
 699          .maxlen = 0,
 700          .mode = 0555,
 701          .child = hpet_root,
 702          },
 703         {}
 704 };
 705
 706 static struct ctl_table_header *sysctl_header;
 707
 708 /*
 709  * Adjustment for when arming the timer with
 710  * initial conditions.  That is, main counter
 711  * ticks expired before interrupts are enabled.
 712  */
 713 #define TICK_CALIBRATE  (1000UL)
 714
 715 static unsigned long __hpet_calibrate(struct hpets *hpetp)
 716 {
 717         struct hpet_timer __iomem *timer = NULL;
 718         unsigned long t, m, count, i, flags, start;
 719         struct hpet_dev *devp;
 720         int j;
 721         struct hpet __iomem *hpet;
 722
 723         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 724                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 725                         timer = devp->hd_timer;
 726                         break;
 727                 }
 728
 729         if (!timer)
 730                 return 0;
 731
 732         hpet = hpetp->hp_hpet;
 733         t = read_counter(&timer->hpet_compare);
 734
 735         i = 0;
 736         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 737
 738         local_irq_save(flags);
 739
 740         start = read_counter(&hpet->hpet_mc);
 741
 742         do {
 743                 m = read_counter(&hpet->hpet_mc);
 744                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 745         } while (i++, (m - start) < count);
 746
 747         local_irq_restore(flags);
 748
 749         return (m - start) / i;
 750 }
 751
 752 static unsigned long hpet_calibrate(struct hpets *hpetp)
 753 {
 754         unsigned long ret = -1;
 755         unsigned long tmp;
 756
 757         /*
 758          * Try to calibrate until return value becomes stable small value.
 759          * If SMI interruption occurs in calibration loop, the return value
 760          * will be big. This avoids its impact.
 761          */
 762         for ( ; ; ) {
 763                 tmp = __hpet_calibrate(hpetp);
 764                 if (ret <= tmp)
 765                         break;
 766                 ret = tmp;
 767         }
 768
 769         return ret;
 770 }
 771
 772 int hpet_alloc(struct hpet_data *hdp)
 773 {
 774         u64 cap, mcfg;
 775         struct hpet_dev *devp;
 776         u32 i, ntimer;
 777         struct hpets *hpetp;
 778         size_t siz;
 779         struct hpet __iomem *hpet;
 780         static struct hpets *last = NULL;
 781         unsigned long period;
 782         unsigned long long temp;
 783         u32 remainder;
 784
 785         /*
 786          * hpet_alloc can be called by platform dependent code.
 787          * If platform dependent code has allocated the hpet that
 788          * ACPI has also reported, then we catch it here.
 789          */
 790         if (hpet_is_known(hdp)) {
 791                 printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
 792                         __func__);
 793                 return 0;
 794         }
 795
 796         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 797                                       sizeof(struct hpet_dev));
 798
 799         hpetp = kzalloc(siz, GFP_KERNEL);
 800
 801         if (!hpetp)
 802                 return -ENOMEM;
 803
 804         hpetp->hp_which = hpet_nhpet++;
 805         hpetp->hp_hpet = hdp->hd_address;
 806         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 807
 808         hpetp->hp_ntimer = hdp->hd_nirqs;
 809
 810         for (i = 0; i < hdp->hd_nirqs; i++)
 811                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 812
 813         hpet = hpetp->hp_hpet;
 814
 815         cap = readq(&hpet->hpet_cap);
 816
 817         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 818
 819         if (hpetp->hp_ntimer != ntimer) {
 820                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 821                        " with number of timers\n");
 822                 kfree(hpetp);
 823                 return -ENODEV;
 824         }
 825
 826         if (last)
 827                 last->hp_next = hpetp;
 828         else
 829                 hpets = hpetp;
 830
 831         last = hpetp;
 832
 833         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 834                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 835         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 836         temp += period >> 1; /* round */
 837         do_div(temp, period);
 838         hpetp->hp_tick_freq = temp; /* ticks per second */
 839
 840         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 841                 hpetp->hp_which, hdp->hd_phys_address,
 842                 hpetp->hp_ntimer > 1 ? "s" : "");
 843         for (i = 0; i < hpetp->hp_ntimer; i++)
 844                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 845         printk("\n");
 846
 847         temp = hpetp->hp_tick_freq;
 848         remainder = do_div(temp, 1000000);
 849         printk(KERN_INFO
 850                 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
 851                 hpetp->hp_which, hpetp->hp_ntimer,
 852                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
 853                 (unsigned) temp, remainder);
 854
 855         mcfg = readq(&hpet->hpet_config);
 856         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 857                 write_counter(0L, &hpet->hpet_mc);
 858                 mcfg |= HPET_ENABLE_CNF_MASK;
 859                 writeq(mcfg, &hpet->hpet_config);
 860         }
 861
 862         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 863                 struct hpet_timer __iomem *timer;
 864
 865                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 866
 867                 devp->hd_hpets = hpetp;
 868                 devp->hd_hpet = hpet;
 869                 devp->hd_timer = timer;
 870
 871                 /*
 872                  * If the timer was reserved by platform code,
 873                  * then make timer unavailable for opens.
 874                  */
 875                 if (hdp->hd_state & (1 << i)) {
 876                         devp->hd_flags = HPET_OPEN;
 877                         continue;
 878                 }
 879
 880                 init_waitqueue_head(&devp->hd_waitqueue);
 881         }
 882
 883         hpetp->hp_delta = hpet_calibrate(hpetp);
 884
 885 /* This clocksource driver currently only works on ia64 */
 886 #ifdef CONFIG_IA64
 887         if (!hpet_clocksource) {
 888                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
 889                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
 890                 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
 891                                                 clocksource_hpet.shift);
 892                 clocksource_register(&clocksource_hpet);
 893                 hpetp->hp_clocksource = &clocksource_hpet;
 894                 hpet_clocksource = &clocksource_hpet;
 895         }
 896 #endif
 897
 898         return 0;
 899 }
 900
 901 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 902 {
 903         struct hpet_data *hdp;
 904         acpi_status status;
 905         struct acpi_resource_address64 addr;
 906
 907         hdp = data;
 908
 909         status = acpi_resource_to_address64(res, &addr);
 910
 911         if (ACPI_SUCCESS(status)) {
 912                 hdp->hd_phys_address = addr.minimum;
 913                 hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 914
 915                 if (hpet_is_known(hdp)) {
 916                         iounmap(hdp->hd_address);
 917                         return AE_ALREADY_EXISTS;
 918                 }
 919         } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 920                 struct acpi_resource_fixed_memory32 *fixmem32;
 921
 922                 fixmem32 = &res->data.fixed_memory32;
 923                 if (!fixmem32)
 924                         return AE_NO_MEMORY;
 925
 926                 hdp->hd_phys_address = fixmem32->address;
 927                 hdp->hd_address = ioremap(fixmem32->address,
 928                                                 HPET_RANGE_SIZE);
 929
 930                 if (hpet_is_known(hdp)) {
 931                         iounmap(hdp->hd_address);
 932                         return AE_ALREADY_EXISTS;
 933                 }
 934         } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
 935                 struct acpi_resource_extended_irq *irqp;
 936                 int i, irq;
 937
 938                 irqp = &res->data.extended_irq;
 939
 940                 for (i = 0; i < irqp->interrupt_count; i++) {
 941                         irq = acpi_register_gsi(NULL, irqp->interrupts[i],
 942                                       irqp->triggering, irqp->polarity);
 943                         if (irq < 0)
 944                                 return AE_ERROR;
 945
 946                         hdp->hd_irq[hdp->hd_nirqs] = irq;
 947                         hdp->hd_nirqs++;
 948                 }
 949         }
 950
 951         return AE_OK;
 952 }
 953
 954 static int hpet_acpi_add(struct acpi_device *device)
 955 {
 956         acpi_status result;
 957         struct hpet_data data;
 958
 959         memset(&data, 0, sizeof(data));
 960
 961         result =
 962             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 963                                 hpet_resources, &data);
 964
 965         if (ACPI_FAILURE(result))
 966                 return -ENODEV;
 967
 968         if (!data.hd_address || !data.hd_nirqs) {
 969                 printk("%s: no address or irqs in _CRS\n", __func__);
 970                 return -ENODEV;
 971         }
 972
 973         return hpet_alloc(&data);
 974 }
 975
 976 static int hpet_acpi_remove(struct acpi_device *device, int type)
 977 {
 978         /* XXX need to unregister clocksource, dealloc mem, etc */
 979         return -EINVAL;
 980 }
 981
 982 static const struct acpi_device_id hpet_device_ids[] = {
 983         {"PNP0103", 0},
 984         {"", 0},
 985 };
 986 MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
 987
 988 static struct acpi_driver hpet_acpi_driver = {
 989         .name = "hpet",
 990         .ids = hpet_device_ids,
 991         .ops = {
 992                 .add = hpet_acpi_add,
 993                 .remove = hpet_acpi_remove,
 994                 },
 995 };
 996
 997 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
 998
 999 static int __init hpet_init(void)
1000 {
1001         int result;
1002
1003         result = misc_register(&hpet_misc);
1004         if (result < 0)
1005                 return -ENODEV;
1006
1007         sysctl_header = register_sysctl_table(dev_root);
1008
1009         result = acpi_bus_register_driver(&hpet_acpi_driver);
1010         if (result < 0) {
1011                 if (sysctl_header)
1012                         unregister_sysctl_table(sysctl_header);
1013                 misc_deregister(&hpet_misc);
1014                 return result;
1015         }
1016
1017         return 0;
1018 }
1019
1020 static void __exit hpet_exit(void)
1021 {
1022         acpi_bus_unregister_driver(&hpet_acpi_driver);
1023
1024         if (sysctl_header)
1025                 unregister_sysctl_table(sysctl_header);
1026         misc_deregister(&hpet_misc);
1027
1028         return;
1029 }
1030
1031 module_init(hpet_init);
1032 module_exit(hpet_exit);
1033 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1034 MODULE_LICENSE("GPL");