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/config.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/kernel.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/proc_fs.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/sysctl.h>
  28 #include <linux/wait.h>
  29 #include <linux/bcd.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/bitops.h>
  32
  33 #include <asm/current.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/system.h>
  36 #include <asm/io.h>
  37 #include <asm/irq.h>
  38 #include <asm/div64.h>
  39
  40 #include <linux/acpi.h>
  41 #include <acpi/acpi_bus.h>
  42 #include <linux/hpet.h>
  43
  44 /*
  45  * The High Precision Event Timer driver.
  46  * This driver is closely modelled after the rtc.c driver.
  47  * http://www.intel.com/hardwaredesign/hpetspec.htm
  48  */
  49 #define HPET_USER_FREQ  (64)
  50 #define HPET_DRIFT      (500)
  51
  52 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
  53
  54 /* A lock for concurrent access by app and isr hpet activity. */
  55 static DEFINE_SPINLOCK(hpet_lock);
  56 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */
  57 static DEFINE_SPINLOCK(hpet_task_lock);
  58
  59 #define HPET_DEV_NAME   (7)
  60
  61 struct hpet_dev {
  62         struct hpets *hd_hpets;
  63         struct hpet __iomem *hd_hpet;
  64         struct hpet_timer __iomem *hd_timer;
  65         unsigned long hd_ireqfreq;
  66         unsigned long hd_irqdata;
  67         wait_queue_head_t hd_waitqueue;
  68         struct fasync_struct *hd_async_queue;
  69         struct hpet_task *hd_task;
  70         unsigned int hd_flags;
  71         unsigned int hd_irq;
  72         unsigned int hd_hdwirq;
  73         char hd_name[HPET_DEV_NAME];
  74 };
  75
  76 struct hpets {
  77         struct hpets *hp_next;
  78         struct hpet __iomem *hp_hpet;
  79         unsigned long hp_hpet_phys;
  80         struct time_interpolator *hp_interpolator;
  81         unsigned long long hp_tick_freq;
  82         unsigned long hp_delta;
  83         unsigned int hp_ntimer;
  84         unsigned int hp_which;
  85         struct hpet_dev hp_dev[1];
  86 };
  87
  88 static struct hpets *hpets;
  89
  90 #define HPET_OPEN               0x0001
  91 #define HPET_IE                 0x0002  /* interrupt enabled */
  92 #define HPET_PERIODIC           0x0004
  93 #define HPET_SHARED_IRQ         0x0008
  94
  95 #if BITS_PER_LONG == 64
  96 #define write_counter(V, MC)    writeq(V, MC)
  97 #define read_counter(MC)        readq(MC)
  98 #else
  99 #define write_counter(V, MC)    writel(V, MC)
 100 #define read_counter(MC)        readl(MC)
 101 #endif
 102
 103 #ifndef readq
 104 static inline unsigned long long readq(void __iomem *addr)
 105 {
 106         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
 107 }
 108 #endif
 109
 110 #ifndef writeq
 111 static inline void writeq(unsigned long long v, void __iomem *addr)
 112 {
 113         writel(v & 0xffffffff, addr);
 114         writel(v >> 32, addr + 4);
 115 }
 116 #endif
 117
 118 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
 119 {
 120         struct hpet_dev *devp;
 121         unsigned long isr;
 122
 123         devp = data;
 124         isr = 1 << (devp - devp->hd_hpets->hp_dev);
 125
 126         if ((devp->hd_flags & HPET_SHARED_IRQ) &&
 127             !(isr & readl(&devp->hd_hpet->hpet_isr)))
 128                 return IRQ_NONE;
 129
 130         spin_lock(&hpet_lock);
 131         devp->hd_irqdata++;
 132
 133         /*
 134          * For non-periodic timers, increment the accumulator.
 135          * This has the effect of treating non-periodic like periodic.
 136          */
 137         if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
 138                 unsigned long m, t;
 139
 140                 t = devp->hd_ireqfreq;
 141                 m = read_counter(&devp->hd_hpet->hpet_mc);
 142                 write_counter(t + m + devp->hd_hpets->hp_delta,
 143                               &devp->hd_timer->hpet_compare);
 144         }
 145
 146         if (devp->hd_flags & HPET_SHARED_IRQ)
 147                 writel(isr, &devp->hd_hpet->hpet_isr);
 148         spin_unlock(&hpet_lock);
 149
 150         spin_lock(&hpet_task_lock);
 151         if (devp->hd_task)
 152                 devp->hd_task->ht_func(devp->hd_task->ht_data);
 153         spin_unlock(&hpet_task_lock);
 154
 155         wake_up_interruptible(&devp->hd_waitqueue);
 156
 157         kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
 158
 159         return IRQ_HANDLED;
 160 }
 161
 162 static int hpet_open(struct inode *inode, struct file *file)
 163 {
 164         struct hpet_dev *devp;
 165         struct hpets *hpetp;
 166         int i;
 167
 168         if (file->f_mode & FMODE_WRITE)
 169                 return -EINVAL;
 170
 171         spin_lock_irq(&hpet_lock);
 172
 173         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 174                 for (i = 0; i < hpetp->hp_ntimer; i++)
 175                         if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
 176                             || hpetp->hp_dev[i].hd_task)
 177                                 continue;
 178                         else {
 179                                 devp = &hpetp->hp_dev[i];
 180                                 break;
 181                         }
 182
 183         if (!devp) {
 184                 spin_unlock_irq(&hpet_lock);
 185                 return -EBUSY;
 186         }
 187
 188         file->private_data = devp;
 189         devp->hd_irqdata = 0;
 190         devp->hd_flags |= HPET_OPEN;
 191         spin_unlock_irq(&hpet_lock);
 192
 193         return 0;
 194 }
 195
 196 static ssize_t
 197 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
 198 {
 199         DECLARE_WAITQUEUE(wait, current);
 200         unsigned long data;
 201         ssize_t retval;
 202         struct hpet_dev *devp;
 203
 204         devp = file->private_data;
 205         if (!devp->hd_ireqfreq)
 206                 return -EIO;
 207
 208         if (count < sizeof(unsigned long))
 209                 return -EINVAL;
 210
 211         add_wait_queue(&devp->hd_waitqueue, &wait);
 212
 213         for ( ; ; ) {
 214                 set_current_state(TASK_INTERRUPTIBLE);
 215
 216                 spin_lock_irq(&hpet_lock);
 217                 data = devp->hd_irqdata;
 218                 devp->hd_irqdata = 0;
 219                 spin_unlock_irq(&hpet_lock);
 220
 221                 if (data)
 222                         break;
 223                 else if (file->f_flags & O_NONBLOCK) {
 224                         retval = -EAGAIN;
 225                         goto out;
 226                 } else if (signal_pending(current)) {
 227                         retval = -ERESTARTSYS;
 228                         goto out;
 229                 }
 230                 schedule();
 231         }
 232
 233         retval = put_user(data, (unsigned long __user *)buf);
 234         if (!retval)
 235                 retval = sizeof(unsigned long);
 236 out:
 237         __set_current_state(TASK_RUNNING);
 238         remove_wait_queue(&devp->hd_waitqueue, &wait);
 239
 240         return retval;
 241 }
 242
 243 static unsigned int hpet_poll(struct file *file, poll_table * wait)
 244 {
 245         unsigned long v;
 246         struct hpet_dev *devp;
 247
 248         devp = file->private_data;
 249
 250         if (!devp->hd_ireqfreq)
 251                 return 0;
 252
 253         poll_wait(file, &devp->hd_waitqueue, wait);
 254
 255         spin_lock_irq(&hpet_lock);
 256         v = devp->hd_irqdata;
 257         spin_unlock_irq(&hpet_lock);
 258
 259         if (v != 0)
 260                 return POLLIN | POLLRDNORM;
 261
 262         return 0;
 263 }
 264
 265 static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 266 {
 267 #ifdef  CONFIG_HPET_MMAP
 268         struct hpet_dev *devp;
 269         unsigned long addr;
 270
 271         if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
 272                 return -EINVAL;
 273
 274         devp = file->private_data;
 275         addr = devp->hd_hpets->hp_hpet_phys;
 276
 277         if (addr & (PAGE_SIZE - 1))
 278                 return -ENOSYS;
 279
 280         vma->vm_flags |= VM_IO;
 281         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 282
 283         if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
 284                                         PAGE_SIZE, vma->vm_page_prot)) {
 285                 printk(KERN_ERR "remap_pfn_range failed in hpet.c\n");
 286                 return -EAGAIN;
 287         }
 288
 289         return 0;
 290 #else
 291         return -ENOSYS;
 292 #endif
 293 }
 294
 295 static int hpet_fasync(int fd, struct file *file, int on)
 296 {
 297         struct hpet_dev *devp;
 298
 299         devp = file->private_data;
 300
 301         if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
 302                 return 0;
 303         else
 304                 return -EIO;
 305 }
 306
 307 static int hpet_release(struct inode *inode, struct file *file)
 308 {
 309         struct hpet_dev *devp;
 310         struct hpet_timer __iomem *timer;
 311         int irq = 0;
 312
 313         devp = file->private_data;
 314         timer = devp->hd_timer;
 315
 316         spin_lock_irq(&hpet_lock);
 317
 318         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 319                &timer->hpet_config);
 320
 321         irq = devp->hd_irq;
 322         devp->hd_irq = 0;
 323
 324         devp->hd_ireqfreq = 0;
 325
 326         if (devp->hd_flags & HPET_PERIODIC
 327             && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 328                 unsigned long v;
 329
 330                 v = readq(&timer->hpet_config);
 331                 v ^= Tn_TYPE_CNF_MASK;
 332                 writeq(v, &timer->hpet_config);
 333         }
 334
 335         devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
 336         spin_unlock_irq(&hpet_lock);
 337
 338         if (irq)
 339                 free_irq(irq, devp);
 340
 341         if (file->f_flags & FASYNC)
 342                 hpet_fasync(-1, file, 0);
 343
 344         file->private_data = NULL;
 345         return 0;
 346 }
 347
 348 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 349
 350 static int
 351 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 352            unsigned long arg)
 353 {
 354         struct hpet_dev *devp;
 355
 356         devp = file->private_data;
 357         return hpet_ioctl_common(devp, cmd, arg, 0);
 358 }
 359
 360 static int hpet_ioctl_ieon(struct hpet_dev *devp)
 361 {
 362         struct hpet_timer __iomem *timer;
 363         struct hpet __iomem *hpet;
 364         struct hpets *hpetp;
 365         int irq;
 366         unsigned long g, v, t, m;
 367         unsigned long flags, isr;
 368
 369         timer = devp->hd_timer;
 370         hpet = devp->hd_hpet;
 371         hpetp = devp->hd_hpets;
 372
 373         if (!devp->hd_ireqfreq)
 374                 return -EIO;
 375
 376         spin_lock_irq(&hpet_lock);
 377
 378         if (devp->hd_flags & HPET_IE) {
 379                 spin_unlock_irq(&hpet_lock);
 380                 return -EBUSY;
 381         }
 382
 383         devp->hd_flags |= HPET_IE;
 384
 385         if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
 386                 devp->hd_flags |= HPET_SHARED_IRQ;
 387         spin_unlock_irq(&hpet_lock);
 388
 389         irq = devp->hd_hdwirq;
 390
 391         if (irq) {
 392                 unsigned long irq_flags;
 393
 394                 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
 395                 irq_flags = devp->hd_flags & HPET_SHARED_IRQ
 396                                                 ? SA_SHIRQ : SA_INTERRUPT;
 397                 if (request_irq(irq, hpet_interrupt, irq_flags,
 398                                 devp->hd_name, (void *)devp)) {
 399                         printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
 400                         irq = 0;
 401                 }
 402         }
 403
 404         if (irq == 0) {
 405                 spin_lock_irq(&hpet_lock);
 406                 devp->hd_flags ^= HPET_IE;
 407                 spin_unlock_irq(&hpet_lock);
 408                 return -EIO;
 409         }
 410
 411         devp->hd_irq = irq;
 412         t = devp->hd_ireqfreq;
 413         v = readq(&timer->hpet_config);
 414         g = v | Tn_INT_ENB_CNF_MASK;
 415
 416         if (devp->hd_flags & HPET_PERIODIC) {
 417                 write_counter(t, &timer->hpet_compare);
 418                 g |= Tn_TYPE_CNF_MASK;
 419                 v |= Tn_TYPE_CNF_MASK;
 420                 writeq(v, &timer->hpet_config);
 421                 v |= Tn_VAL_SET_CNF_MASK;
 422                 writeq(v, &timer->hpet_config);
 423                 local_irq_save(flags);
 424                 m = read_counter(&hpet->hpet_mc);
 425                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 426         } else {
 427                 local_irq_save(flags);
 428                 m = read_counter(&hpet->hpet_mc);
 429                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 430         }
 431
 432         if (devp->hd_flags & HPET_SHARED_IRQ) {
 433                 isr = 1 << (devp - devp->hd_hpets->hp_dev);
 434                 writel(isr, &hpet->hpet_isr);
 435         }
 436         writeq(g, &timer->hpet_config);
 437         local_irq_restore(flags);
 438
 439         return 0;
 440 }
 441
 442 /* converts Hz to number of timer ticks */
 443 static inline unsigned long hpet_time_div(struct hpets *hpets,
 444                                           unsigned long dis)
 445 {
 446         unsigned long long m;
 447
 448         m = hpets->hp_tick_freq + (dis >> 1);
 449         do_div(m, dis);
 450         return (unsigned long)m;
 451 }
 452
 453 static int
 454 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 455 {
 456         struct hpet_timer __iomem *timer;
 457         struct hpet __iomem *hpet;
 458         struct hpets *hpetp;
 459         int err;
 460         unsigned long v;
 461
 462         switch (cmd) {
 463         case HPET_IE_OFF:
 464         case HPET_INFO:
 465         case HPET_EPI:
 466         case HPET_DPI:
 467         case HPET_IRQFREQ:
 468                 timer = devp->hd_timer;
 469                 hpet = devp->hd_hpet;
 470                 hpetp = devp->hd_hpets;
 471                 break;
 472         case HPET_IE_ON:
 473                 return hpet_ioctl_ieon(devp);
 474         default:
 475                 return -EINVAL;
 476         }
 477
 478         err = 0;
 479
 480         switch (cmd) {
 481         case HPET_IE_OFF:
 482                 if ((devp->hd_flags & HPET_IE) == 0)
 483                         break;
 484                 v = readq(&timer->hpet_config);
 485                 v &= ~Tn_INT_ENB_CNF_MASK;
 486                 writeq(v, &timer->hpet_config);
 487                 if (devp->hd_irq) {
 488                         free_irq(devp->hd_irq, devp);
 489                         devp->hd_irq = 0;
 490                 }
 491                 devp->hd_flags ^= HPET_IE;
 492                 break;
 493         case HPET_INFO:
 494                 {
 495                         struct hpet_info info;
 496
 497                         if (devp->hd_ireqfreq)
 498                                 info.hi_ireqfreq =
 499                                         hpet_time_div(hpetp, devp->hd_ireqfreq);
 500                         else
 501                                 info.hi_ireqfreq = 0;
 502                         info.hi_flags =
 503                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 504                         info.hi_hpet = devp->hd_hpets->hp_which;
 505                         info.hi_timer = devp - devp->hd_hpets->hp_dev;
 506                         if (kernel)
 507                                 memcpy((void *)arg, &info, sizeof(info));
 508                         else
 509                                 if (copy_to_user((void __user *)arg, &info,
 510                                                  sizeof(info)))
 511                                         err = -EFAULT;
 512                         break;
 513                 }
 514         case HPET_EPI:
 515                 v = readq(&timer->hpet_config);
 516                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 517                         err = -ENXIO;
 518                         break;
 519                 }
 520                 devp->hd_flags |= HPET_PERIODIC;
 521                 break;
 522         case HPET_DPI:
 523                 v = readq(&timer->hpet_config);
 524                 if ((v & Tn_PER_INT_CAP_MASK) == 0) {
 525                         err = -ENXIO;
 526                         break;
 527                 }
 528                 if (devp->hd_flags & HPET_PERIODIC &&
 529                     readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
 530                         v = readq(&timer->hpet_config);
 531                         v ^= Tn_TYPE_CNF_MASK;
 532                         writeq(v, &timer->hpet_config);
 533                 }
 534                 devp->hd_flags &= ~HPET_PERIODIC;
 535                 break;
 536         case HPET_IRQFREQ:
 537                 if (!kernel && (arg > hpet_max_freq) &&
 538                     !capable(CAP_SYS_RESOURCE)) {
 539                         err = -EACCES;
 540                         break;
 541                 }
 542
 543                 if (!arg) {
 544                         err = -EINVAL;
 545                         break;
 546                 }
 547
 548                 devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
 549         }
 550
 551         return err;
 552 }
 553
 554 static struct file_operations hpet_fops = {
 555         .owner = THIS_MODULE,
 556         .llseek = no_llseek,
 557         .read = hpet_read,
 558         .poll = hpet_poll,
 559         .ioctl = hpet_ioctl,
 560         .open = hpet_open,
 561         .release = hpet_release,
 562         .fasync = hpet_fasync,
 563         .mmap = hpet_mmap,
 564 };
 565
 566 EXPORT_SYMBOL(hpet_alloc);
 567 EXPORT_SYMBOL(hpet_register);
 568 EXPORT_SYMBOL(hpet_unregister);
 569 EXPORT_SYMBOL(hpet_control);
 570
 571 int hpet_register(struct hpet_task *tp, int periodic)
 572 {
 573         unsigned int i;
 574         u64 mask;
 575         struct hpet_timer __iomem *timer;
 576         struct hpet_dev *devp;
 577         struct hpets *hpetp;
 578
 579         switch (periodic) {
 580         case 1:
 581                 mask = Tn_PER_INT_CAP_MASK;
 582                 break;
 583         case 0:
 584                 mask = 0;
 585                 break;
 586         default:
 587                 return -EINVAL;
 588         }
 589
 590         tp->ht_opaque = NULL;
 591
 592         spin_lock_irq(&hpet_task_lock);
 593         spin_lock(&hpet_lock);
 594
 595         for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
 596                 for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
 597                      i < hpetp->hp_ntimer; i++, timer++) {
 598                         if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
 599                             != mask)
 600                                 continue;
 601
 602                         devp = &hpetp->hp_dev[i];
 603
 604                         if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
 605                                 devp = NULL;
 606                                 continue;
 607                         }
 608
 609                         tp->ht_opaque = devp;
 610                         devp->hd_task = tp;
 611                         break;
 612                 }
 613
 614         spin_unlock(&hpet_lock);
 615         spin_unlock_irq(&hpet_task_lock);
 616
 617         if (tp->ht_opaque)
 618                 return 0;
 619         else
 620                 return -EBUSY;
 621 }
 622
 623 static inline int hpet_tpcheck(struct hpet_task *tp)
 624 {
 625         struct hpet_dev *devp;
 626         struct hpets *hpetp;
 627
 628         devp = tp->ht_opaque;
 629
 630         if (!devp)
 631                 return -ENXIO;
 632
 633         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 634                 if (devp >= hpetp->hp_dev
 635                     && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
 636                     && devp->hd_hpet == hpetp->hp_hpet)
 637                         return 0;
 638
 639         return -ENXIO;
 640 }
 641
 642 int hpet_unregister(struct hpet_task *tp)
 643 {
 644         struct hpet_dev *devp;
 645         struct hpet_timer __iomem *timer;
 646         int err;
 647
 648         if ((err = hpet_tpcheck(tp)))
 649                 return err;
 650
 651         spin_lock_irq(&hpet_task_lock);
 652         spin_lock(&hpet_lock);
 653
 654         devp = tp->ht_opaque;
 655         if (devp->hd_task != tp) {
 656                 spin_unlock(&hpet_lock);
 657                 spin_unlock_irq(&hpet_task_lock);
 658                 return -ENXIO;
 659         }
 660
 661         timer = devp->hd_timer;
 662         writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
 663                &timer->hpet_config);
 664         devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
 665         devp->hd_task = NULL;
 666         spin_unlock(&hpet_lock);
 667         spin_unlock_irq(&hpet_task_lock);
 668
 669         return 0;
 670 }
 671
 672 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
 673 {
 674         struct hpet_dev *devp;
 675         int err;
 676
 677         if ((err = hpet_tpcheck(tp)))
 678                 return err;
 679
 680         spin_lock_irq(&hpet_lock);
 681         devp = tp->ht_opaque;
 682         if (devp->hd_task != tp) {
 683                 spin_unlock_irq(&hpet_lock);
 684                 return -ENXIO;
 685         }
 686         spin_unlock_irq(&hpet_lock);
 687         return hpet_ioctl_common(devp, cmd, arg, 1);
 688 }
 689
 690 static ctl_table hpet_table[] = {
 691         {
 692          .ctl_name = 1,
 693          .procname = "max-user-freq",
 694          .data = &hpet_max_freq,
 695          .maxlen = sizeof(int),
 696          .mode = 0644,
 697          .proc_handler = &proc_dointvec,
 698          },
 699         {.ctl_name = 0}
 700 };
 701
 702 static ctl_table hpet_root[] = {
 703         {
 704          .ctl_name = 1,
 705          .procname = "hpet",
 706          .maxlen = 0,
 707          .mode = 0555,
 708          .child = hpet_table,
 709          },
 710         {.ctl_name = 0}
 711 };
 712
 713 static ctl_table dev_root[] = {
 714         {
 715          .ctl_name = CTL_DEV,
 716          .procname = "dev",
 717          .maxlen = 0,
 718          .mode = 0555,
 719          .child = hpet_root,
 720          },
 721         {.ctl_name = 0}
 722 };
 723
 724 static struct ctl_table_header *sysctl_header;
 725
 726 static void hpet_register_interpolator(struct hpets *hpetp)
 727 {
 728 #ifdef  CONFIG_TIME_INTERPOLATION
 729         struct time_interpolator *ti;
 730
 731         ti = kmalloc(sizeof(*ti), GFP_KERNEL);
 732         if (!ti)
 733                 return;
 734
 735         memset(ti, 0, sizeof(*ti));
 736         ti->source = TIME_SOURCE_MMIO64;
 737         ti->shift = 10;
 738         ti->addr = &hpetp->hp_hpet->hpet_mc;
 739         ti->frequency = hpetp->hp_tick_freq;
 740         ti->drift = HPET_DRIFT;
 741         ti->mask = -1;
 742
 743         hpetp->hp_interpolator = ti;
 744         register_time_interpolator(ti);
 745 #endif
 746 }
 747
 748 /*
 749  * Adjustment for when arming the timer with
 750  * initial conditions.  That is, main counter
 751  * ticks expired before interrupts are enabled.
 752  */
 753 #define TICK_CALIBRATE  (1000UL)
 754
 755 static unsigned long hpet_calibrate(struct hpets *hpetp)
 756 {
 757         struct hpet_timer __iomem *timer = NULL;
 758         unsigned long t, m, count, i, flags, start;
 759         struct hpet_dev *devp;
 760         int j;
 761         struct hpet __iomem *hpet;
 762
 763         for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
 764                 if ((devp->hd_flags & HPET_OPEN) == 0) {
 765                         timer = devp->hd_timer;
 766                         break;
 767                 }
 768
 769         if (!timer)
 770                 return 0;
 771
 772         hpet = hpetp->hp_hpet;
 773         t = read_counter(&timer->hpet_compare);
 774
 775         i = 0;
 776         count = hpet_time_div(hpetp, TICK_CALIBRATE);
 777
 778         local_irq_save(flags);
 779
 780         start = read_counter(&hpet->hpet_mc);
 781
 782         do {
 783                 m = read_counter(&hpet->hpet_mc);
 784                 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
 785         } while (i++, (m - start) < count);
 786
 787         local_irq_restore(flags);
 788
 789         return (m - start) / i;
 790 }
 791
 792 int hpet_alloc(struct hpet_data *hdp)
 793 {
 794         u64 cap, mcfg;
 795         struct hpet_dev *devp;
 796         u32 i, ntimer;
 797         struct hpets *hpetp;
 798         size_t siz;
 799         struct hpet __iomem *hpet;
 800         static struct hpets *last = (struct hpets *)0;
 801         unsigned long ns, period;
 802         unsigned long long temp;
 803
 804         /*
 805          * hpet_alloc can be called by platform dependent code.
 806          * if platform dependent code has allocated the hpet
 807          * ACPI also reports hpet, then we catch it here.
 808          */
 809         for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 810                 if (hpetp->hp_hpet == hdp->hd_address)
 811                         return 0;
 812
 813         siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
 814                                       sizeof(struct hpet_dev));
 815
 816         hpetp = kmalloc(siz, GFP_KERNEL);
 817
 818         if (!hpetp)
 819                 return -ENOMEM;
 820
 821         memset(hpetp, 0, siz);
 822
 823         hpetp->hp_which = hpet_nhpet++;
 824         hpetp->hp_hpet = hdp->hd_address;
 825         hpetp->hp_hpet_phys = hdp->hd_phys_address;
 826
 827         hpetp->hp_ntimer = hdp->hd_nirqs;
 828
 829         for (i = 0; i < hdp->hd_nirqs; i++)
 830                 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 831
 832         hpet = hpetp->hp_hpet;
 833
 834         cap = readq(&hpet->hpet_cap);
 835
 836         ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
 837
 838         if (hpetp->hp_ntimer != ntimer) {
 839                 printk(KERN_WARNING "hpet: number irqs doesn't agree"
 840                        " with number of timers\n");
 841                 kfree(hpetp);
 842                 return -ENODEV;
 843         }
 844
 845         if (last)
 846                 last->hp_next = hpetp;
 847         else
 848                 hpets = hpetp;
 849
 850         last = hpetp;
 851
 852         period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
 853                 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
 854         temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
 855         temp += period >> 1; /* round */
 856         do_div(temp, period);
 857         hpetp->hp_tick_freq = temp; /* ticks per second */
 858
 859         printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
 860                 hpetp->hp_which, hdp->hd_phys_address,
 861                 hpetp->hp_ntimer > 1 ? "s" : "");
 862         for (i = 0; i < hpetp->hp_ntimer; i++)
 863                 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 864         printk("\n");
 865
 866         ns = period / 1000000;  /* convert to nanoseconds, 10^-9 */
 867         printk(KERN_INFO "hpet%d: %ldns tick, %d %d-bit timers\n",
 868                 hpetp->hp_which, ns, hpetp->hp_ntimer,
 869                 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32);
 870
 871         mcfg = readq(&hpet->hpet_config);
 872         if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
 873                 write_counter(0L, &hpet->hpet_mc);
 874                 mcfg |= HPET_ENABLE_CNF_MASK;
 875                 writeq(mcfg, &hpet->hpet_config);
 876         }
 877
 878         for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
 879                 struct hpet_timer __iomem *timer;
 880
 881                 timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
 882
 883                 devp->hd_hpets = hpetp;
 884                 devp->hd_hpet = hpet;
 885                 devp->hd_timer = timer;
 886
 887                 /*
 888                  * If the timer was reserved by platform code,
 889                  * then make timer unavailable for opens.
 890                  */
 891                 if (hdp->hd_state & (1 << i)) {
 892                         devp->hd_flags = HPET_OPEN;
 893                         continue;
 894                 }
 895
 896                 init_waitqueue_head(&devp->hd_waitqueue);
 897         }
 898
 899         hpetp->hp_delta = hpet_calibrate(hpetp);
 900         hpet_register_interpolator(hpetp);
 901
 902         return 0;
 903 }
 904
 905 static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 906 {
 907         struct hpet_data *hdp;
 908         acpi_status status;
 909         struct acpi_resource_address64 addr;
 910         struct hpets *hpetp;
 911
 912         hdp = data;
 913
 914         status = acpi_resource_to_address64(res, &addr);
 915
 916         if (ACPI_SUCCESS(status)) {
 917                 unsigned long size;
 918
 919                 size = addr.max_address_range - addr.min_address_range + 1;
 920                 hdp->hd_phys_address = addr.min_address_range;
 921                 hdp->hd_address = ioremap(addr.min_address_range, size);
 922
 923                 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
 924                         if (hpetp->hp_hpet == hdp->hd_address)
 925                                 return -EBUSY;
 926         } else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
 927                 struct acpi_resource_ext_irq *irqp;
 928                 int i;
 929
 930                 irqp = &res->data.extended_irq;
 931
 932                 if (irqp->number_of_interrupts > 0) {
 933                         hdp->hd_nirqs = irqp->number_of_interrupts;
 934
 935                         for (i = 0; i < hdp->hd_nirqs; i++) {
 936                                 int rc =
 937                                     acpi_register_gsi(irqp->interrupts[i],
 938                                                       irqp->edge_level,
 939                                                       irqp->active_high_low);
 940                                 if (rc < 0)
 941                                         return AE_ERROR;
 942                                 hdp->hd_irq[i] = rc;
 943                         }
 944                 }
 945         }
 946
 947         return AE_OK;
 948 }
 949
 950 static int hpet_acpi_add(struct acpi_device *device)
 951 {
 952         acpi_status result;
 953         struct hpet_data data;
 954
 955         memset(&data, 0, sizeof(data));
 956
 957         result =
 958             acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 959                                 hpet_resources, &data);
 960
 961         if (ACPI_FAILURE(result))
 962                 return -ENODEV;
 963
 964         if (!data.hd_address || !data.hd_nirqs) {
 965                 printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
 966                 return -ENODEV;
 967         }
 968
 969         return hpet_alloc(&data);
 970 }
 971
 972 static int hpet_acpi_remove(struct acpi_device *device, int type)
 973 {
 974         /* XXX need to unregister interpolator, dealloc mem, etc */
 975         return -EINVAL;
 976 }
 977
 978 static struct acpi_driver hpet_acpi_driver = {
 979         .name = "hpet",
 980         .ids = "PNP0103",
 981         .ops = {
 982                 .add = hpet_acpi_add,
 983                 .remove = hpet_acpi_remove,
 984                 },
 985 };
 986
 987 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };
 988
 989 static int __init hpet_init(void)
 990 {
 991         int result;
 992
 993         result = misc_register(&hpet_misc);
 994         if (result < 0)
 995                 return -ENODEV;
 996
 997         sysctl_header = register_sysctl_table(dev_root, 0);
 998
 999         result = acpi_bus_register_driver(&hpet_acpi_driver);
1000         if (result < 0) {
1001                 if (sysctl_header)
1002                         unregister_sysctl_table(sysctl_header);
1003                 misc_deregister(&hpet_misc);
1004                 return result;
1005         }
1006
1007         return 0;
1008 }
1009
1010 static void __exit hpet_exit(void)
1011 {
1012         acpi_bus_unregister_driver(&hpet_acpi_driver);
1013
1014         if (sysctl_header)
1015                 unregister_sysctl_table(sysctl_header);
1016         misc_deregister(&hpet_misc);
1017
1018         return;
1019 }
1020
1021 module_init(hpet_init);
1022 module_exit(hpet_exit);
1023 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
1024 MODULE_LICENSE("GPL");