1 /* 2 * Intel & MS High Precision Event Timer Implementation. 3 * 4 * Copyright (C) 2003 Intel Corporation 5 * Venki Pallipadi 6 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. 7 * Bob Picco <robert.picco@hp.com> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/interrupt.h> 15 #include <linux/module.h> 16 #include <linux/kernel.h> 17 #include <linux/types.h> 18 #include <linux/miscdevice.h> 19 #include <linux/major.h> 20 #include <linux/ioport.h> 21 #include <linux/fcntl.h> 22 #include <linux/init.h> 23 #include <linux/poll.h> 24 #include <linux/proc_fs.h> 25 #include <linux/spinlock.h> 26 #include <linux/sysctl.h> 27 #include <linux/wait.h> 28 #include <linux/bcd.h> 29 #include <linux/seq_file.h> 30 #include <linux/bitops.h> 31 32 #include <asm/current.h> 33 #include <asm/uaccess.h> 34 #include <asm/system.h> 35 #include <asm/io.h> 36 #include <asm/irq.h> 37 #include <asm/div64.h> 38 39 #include <linux/acpi.h> 40 #include <acpi/acpi_bus.h> 41 #include <linux/hpet.h> 42 43 /* 44 * The High Precision Event Timer driver. 45 * This driver is closely modelled after the rtc.c driver. 46 * http://www.intel.com/hardwaredesign/hpetspec.htm 47 */ 48 #define HPET_USER_FREQ (64) 49 #define HPET_DRIFT (500) 50 51 #define HPET_RANGE_SIZE 1024 /* from HPET spec */ 52 53 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 54 55 /* A lock for concurrent access by app and isr hpet activity. */ 56 static DEFINE_SPINLOCK(hpet_lock); 57 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */ 58 static DEFINE_SPINLOCK(hpet_task_lock); 59 60 #define HPET_DEV_NAME (7) 61 62 struct hpet_dev { 63 struct hpets *hd_hpets; 64 struct hpet __iomem *hd_hpet; 65 struct hpet_timer __iomem *hd_timer; 66 unsigned long hd_ireqfreq; 67 unsigned long hd_irqdata; 68 wait_queue_head_t hd_waitqueue; 69 struct fasync_struct *hd_async_queue; 70 struct hpet_task *hd_task; 71 unsigned int hd_flags; 72 unsigned int hd_irq; 73 unsigned int hd_hdwirq; 74 char hd_name[HPET_DEV_NAME]; 75 }; 76 77 struct hpets { 78 struct hpets *hp_next; 79 struct hpet __iomem *hp_hpet; 80 unsigned long hp_hpet_phys; 81 struct time_interpolator *hp_interpolator; 82 unsigned long long hp_tick_freq; 83 unsigned long hp_delta; 84 unsigned int hp_ntimer; 85 unsigned int hp_which; 86 struct hpet_dev hp_dev[1]; 87 }; 88 89 static struct hpets *hpets; 90 91 #define HPET_OPEN 0x0001 92 #define HPET_IE 0x0002 /* interrupt enabled */ 93 #define HPET_PERIODIC 0x0004 94 #define HPET_SHARED_IRQ 0x0008 95 96 #if BITS_PER_LONG == 64 97 #define write_counter(V, MC) writeq(V, MC) 98 #define read_counter(MC) readq(MC) 99 #else 100 #define write_counter(V, MC) writel(V, MC) 101 #define read_counter(MC) readl(MC) 102 #endif 103 104 #ifndef readq 105 static inline unsigned long long readq(void __iomem *addr) 106 { 107 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 108 } 109 #endif 110 111 #ifndef writeq 112 static inline void writeq(unsigned long long v, void __iomem *addr) 113 { 114 writel(v & 0xffffffff, addr); 115 writel(v >> 32, addr + 4); 116 } 117 #endif 118 119 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs) 120 { 121 struct hpet_dev *devp; 122 unsigned long isr; 123 124 devp = data; 125 isr = 1 << (devp - devp->hd_hpets->hp_dev); 126 127 if ((devp->hd_flags & HPET_SHARED_IRQ) && 128 !(isr & readl(&devp->hd_hpet->hpet_isr))) 129 return IRQ_NONE; 130 131 spin_lock(&hpet_lock); 132 devp->hd_irqdata++; 133 134 /* 135 * For non-periodic timers, increment the accumulator. 136 * This has the effect of treating non-periodic like periodic. 137 */ 138 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 139 unsigned long m, t; 140 141 t = devp->hd_ireqfreq; 142 m = read_counter(&devp->hd_hpet->hpet_mc); 143 write_counter(t + m + devp->hd_hpets->hp_delta, 144 &devp->hd_timer->hpet_compare); 145 } 146 147 if (devp->hd_flags & HPET_SHARED_IRQ) 148 writel(isr, &devp->hd_hpet->hpet_isr); 149 spin_unlock(&hpet_lock); 150 151 spin_lock(&hpet_task_lock); 152 if (devp->hd_task) 153 devp->hd_task->ht_func(devp->hd_task->ht_data); 154 spin_unlock(&hpet_task_lock); 155 156 wake_up_interruptible(&devp->hd_waitqueue); 157 158 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 159 160 return IRQ_HANDLED; 161 } 162 163 static int hpet_open(struct inode *inode, struct file *file) 164 { 165 struct hpet_dev *devp; 166 struct hpets *hpetp; 167 int i; 168 169 if (file->f_mode & FMODE_WRITE) 170 return -EINVAL; 171 172 spin_lock_irq(&hpet_lock); 173 174 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 175 for (i = 0; i < hpetp->hp_ntimer; i++) 176 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN 177 || hpetp->hp_dev[i].hd_task) 178 continue; 179 else { 180 devp = &hpetp->hp_dev[i]; 181 break; 182 } 183 184 if (!devp) { 185 spin_unlock_irq(&hpet_lock); 186 return -EBUSY; 187 } 188 189 file->private_data = devp; 190 devp->hd_irqdata = 0; 191 devp->hd_flags |= HPET_OPEN; 192 spin_unlock_irq(&hpet_lock); 193 194 return 0; 195 } 196 197 static ssize_t 198 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 199 { 200 DECLARE_WAITQUEUE(wait, current); 201 unsigned long data; 202 ssize_t retval; 203 struct hpet_dev *devp; 204 205 devp = file->private_data; 206 if (!devp->hd_ireqfreq) 207 return -EIO; 208 209 if (count < sizeof(unsigned long)) 210 return -EINVAL; 211 212 add_wait_queue(&devp->hd_waitqueue, &wait); 213 214 for ( ; ; ) { 215 set_current_state(TASK_INTERRUPTIBLE); 216 217 spin_lock_irq(&hpet_lock); 218 data = devp->hd_irqdata; 219 devp->hd_irqdata = 0; 220 spin_unlock_irq(&hpet_lock); 221 222 if (data) 223 break; 224 else if (file->f_flags & O_NONBLOCK) { 225 retval = -EAGAIN; 226 goto out; 227 } else if (signal_pending(current)) { 228 retval = -ERESTARTSYS; 229 goto out; 230 } 231 schedule(); 232 } 233 234 retval = put_user(data, (unsigned long __user *)buf); 235 if (!retval) 236 retval = sizeof(unsigned long); 237 out: 238 __set_current_state(TASK_RUNNING); 239 remove_wait_queue(&devp->hd_waitqueue, &wait); 240 241 return retval; 242 } 243 244 static unsigned int hpet_poll(struct file *file, poll_table * wait) 245 { 246 unsigned long v; 247 struct hpet_dev *devp; 248 249 devp = file->private_data; 250 251 if (!devp->hd_ireqfreq) 252 return 0; 253 254 poll_wait(file, &devp->hd_waitqueue, wait); 255 256 spin_lock_irq(&hpet_lock); 257 v = devp->hd_irqdata; 258 spin_unlock_irq(&hpet_lock); 259 260 if (v != 0) 261 return POLLIN | POLLRDNORM; 262 263 return 0; 264 } 265 266 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 267 { 268 #ifdef CONFIG_HPET_MMAP 269 struct hpet_dev *devp; 270 unsigned long addr; 271 272 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 273 return -EINVAL; 274 275 devp = file->private_data; 276 addr = devp->hd_hpets->hp_hpet_phys; 277 278 if (addr & (PAGE_SIZE - 1)) 279 return -ENOSYS; 280 281 vma->vm_flags |= VM_IO; 282 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 283 284 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 285 PAGE_SIZE, vma->vm_page_prot)) { 286 printk(KERN_ERR "%s: io_remap_pfn_range failed\n", 287 __FUNCTION__); 288 return -EAGAIN; 289 } 290 291 return 0; 292 #else 293 return -ENOSYS; 294 #endif 295 } 296 297 static int hpet_fasync(int fd, struct file *file, int on) 298 { 299 struct hpet_dev *devp; 300 301 devp = file->private_data; 302 303 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 304 return 0; 305 else 306 return -EIO; 307 } 308 309 static int hpet_release(struct inode *inode, struct file *file) 310 { 311 struct hpet_dev *devp; 312 struct hpet_timer __iomem *timer; 313 int irq = 0; 314 315 devp = file->private_data; 316 timer = devp->hd_timer; 317 318 spin_lock_irq(&hpet_lock); 319 320 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 321 &timer->hpet_config); 322 323 irq = devp->hd_irq; 324 devp->hd_irq = 0; 325 326 devp->hd_ireqfreq = 0; 327 328 if (devp->hd_flags & HPET_PERIODIC 329 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 330 unsigned long v; 331 332 v = readq(&timer->hpet_config); 333 v ^= Tn_TYPE_CNF_MASK; 334 writeq(v, &timer->hpet_config); 335 } 336 337 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 338 spin_unlock_irq(&hpet_lock); 339 340 if (irq) 341 free_irq(irq, devp); 342 343 if (file->f_flags & FASYNC) 344 hpet_fasync(-1, file, 0); 345 346 file->private_data = NULL; 347 return 0; 348 } 349 350 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 351 352 static int 353 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 354 unsigned long arg) 355 { 356 struct hpet_dev *devp; 357 358 devp = file->private_data; 359 return hpet_ioctl_common(devp, cmd, arg, 0); 360 } 361 362 static int hpet_ioctl_ieon(struct hpet_dev *devp) 363 { 364 struct hpet_timer __iomem *timer; 365 struct hpet __iomem *hpet; 366 struct hpets *hpetp; 367 int irq; 368 unsigned long g, v, t, m; 369 unsigned long flags, isr; 370 371 timer = devp->hd_timer; 372 hpet = devp->hd_hpet; 373 hpetp = devp->hd_hpets; 374 375 if (!devp->hd_ireqfreq) 376 return -EIO; 377 378 spin_lock_irq(&hpet_lock); 379 380 if (devp->hd_flags & HPET_IE) { 381 spin_unlock_irq(&hpet_lock); 382 return -EBUSY; 383 } 384 385 devp->hd_flags |= HPET_IE; 386 387 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 388 devp->hd_flags |= HPET_SHARED_IRQ; 389 spin_unlock_irq(&hpet_lock); 390 391 irq = devp->hd_hdwirq; 392 393 if (irq) { 394 unsigned long irq_flags; 395 396 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 397 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 398 ? IRQF_SHARED : IRQF_DISABLED; 399 if (request_irq(irq, hpet_interrupt, irq_flags, 400 devp->hd_name, (void *)devp)) { 401 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 402 irq = 0; 403 } 404 } 405 406 if (irq == 0) { 407 spin_lock_irq(&hpet_lock); 408 devp->hd_flags ^= HPET_IE; 409 spin_unlock_irq(&hpet_lock); 410 return -EIO; 411 } 412 413 devp->hd_irq = irq; 414 t = devp->hd_ireqfreq; 415 v = readq(&timer->hpet_config); 416 g = v | Tn_INT_ENB_CNF_MASK; 417 418 if (devp->hd_flags & HPET_PERIODIC) { 419 write_counter(t, &timer->hpet_compare); 420 g |= Tn_TYPE_CNF_MASK; 421 v |= Tn_TYPE_CNF_MASK; 422 writeq(v, &timer->hpet_config); 423 v |= Tn_VAL_SET_CNF_MASK; 424 writeq(v, &timer->hpet_config); 425 local_irq_save(flags); 426 m = read_counter(&hpet->hpet_mc); 427 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 428 } else { 429 local_irq_save(flags); 430 m = read_counter(&hpet->hpet_mc); 431 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 432 } 433 434 if (devp->hd_flags & HPET_SHARED_IRQ) { 435 isr = 1 << (devp - devp->hd_hpets->hp_dev); 436 writel(isr, &hpet->hpet_isr); 437 } 438 writeq(g, &timer->hpet_config); 439 local_irq_restore(flags); 440 441 return 0; 442 } 443 444 /* converts Hz to number of timer ticks */ 445 static inline unsigned long hpet_time_div(struct hpets *hpets, 446 unsigned long dis) 447 { 448 unsigned long long m; 449 450 m = hpets->hp_tick_freq + (dis >> 1); 451 do_div(m, dis); 452 return (unsigned long)m; 453 } 454 455 static int 456 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 457 { 458 struct hpet_timer __iomem *timer; 459 struct hpet __iomem *hpet; 460 struct hpets *hpetp; 461 int err; 462 unsigned long v; 463 464 switch (cmd) { 465 case HPET_IE_OFF: 466 case HPET_INFO: 467 case HPET_EPI: 468 case HPET_DPI: 469 case HPET_IRQFREQ: 470 timer = devp->hd_timer; 471 hpet = devp->hd_hpet; 472 hpetp = devp->hd_hpets; 473 break; 474 case HPET_IE_ON: 475 return hpet_ioctl_ieon(devp); 476 default: 477 return -EINVAL; 478 } 479 480 err = 0; 481 482 switch (cmd) { 483 case HPET_IE_OFF: 484 if ((devp->hd_flags & HPET_IE) == 0) 485 break; 486 v = readq(&timer->hpet_config); 487 v &= ~Tn_INT_ENB_CNF_MASK; 488 writeq(v, &timer->hpet_config); 489 if (devp->hd_irq) { 490 free_irq(devp->hd_irq, devp); 491 devp->hd_irq = 0; 492 } 493 devp->hd_flags ^= HPET_IE; 494 break; 495 case HPET_INFO: 496 { 497 struct hpet_info info; 498 499 if (devp->hd_ireqfreq) 500 info.hi_ireqfreq = 501 hpet_time_div(hpetp, devp->hd_ireqfreq); 502 else 503 info.hi_ireqfreq = 0; 504 info.hi_flags = 505 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 506 info.hi_hpet = hpetp->hp_which; 507 info.hi_timer = devp - hpetp->hp_dev; 508 if (kernel) 509 memcpy((void *)arg, &info, sizeof(info)); 510 else 511 if (copy_to_user((void __user *)arg, &info, 512 sizeof(info))) 513 err = -EFAULT; 514 break; 515 } 516 case HPET_EPI: 517 v = readq(&timer->hpet_config); 518 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 519 err = -ENXIO; 520 break; 521 } 522 devp->hd_flags |= HPET_PERIODIC; 523 break; 524 case HPET_DPI: 525 v = readq(&timer->hpet_config); 526 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 527 err = -ENXIO; 528 break; 529 } 530 if (devp->hd_flags & HPET_PERIODIC && 531 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 532 v = readq(&timer->hpet_config); 533 v ^= Tn_TYPE_CNF_MASK; 534 writeq(v, &timer->hpet_config); 535 } 536 devp->hd_flags &= ~HPET_PERIODIC; 537 break; 538 case HPET_IRQFREQ: 539 if (!kernel && (arg > hpet_max_freq) && 540 !capable(CAP_SYS_RESOURCE)) { 541 err = -EACCES; 542 break; 543 } 544 545 if (!arg) { 546 err = -EINVAL; 547 break; 548 } 549 550 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 551 } 552 553 return err; 554 } 555 556 static const struct file_operations hpet_fops = { 557 .owner = THIS_MODULE, 558 .llseek = no_llseek, 559 .read = hpet_read, 560 .poll = hpet_poll, 561 .ioctl = hpet_ioctl, 562 .open = hpet_open, 563 .release = hpet_release, 564 .fasync = hpet_fasync, 565 .mmap = hpet_mmap, 566 }; 567 568 static int hpet_is_known(struct hpet_data *hdp) 569 { 570 struct hpets *hpetp; 571 572 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 573 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 574 return 1; 575 576 return 0; 577 } 578 579 EXPORT_SYMBOL(hpet_alloc); 580 EXPORT_SYMBOL(hpet_register); 581 EXPORT_SYMBOL(hpet_unregister); 582 EXPORT_SYMBOL(hpet_control); 583 584 int hpet_register(struct hpet_task *tp, int periodic) 585 { 586 unsigned int i; 587 u64 mask; 588 struct hpet_timer __iomem *timer; 589 struct hpet_dev *devp; 590 struct hpets *hpetp; 591 592 switch (periodic) { 593 case 1: 594 mask = Tn_PER_INT_CAP_MASK; 595 break; 596 case 0: 597 mask = 0; 598 break; 599 default: 600 return -EINVAL; 601 } 602 603 tp->ht_opaque = NULL; 604 605 spin_lock_irq(&hpet_task_lock); 606 spin_lock(&hpet_lock); 607 608 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 609 for (timer = hpetp->hp_hpet->hpet_timers, i = 0; 610 i < hpetp->hp_ntimer; i++, timer++) { 611 if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK) 612 != mask) 613 continue; 614 615 devp = &hpetp->hp_dev[i]; 616 617 if (devp->hd_flags & HPET_OPEN || devp->hd_task) { 618 devp = NULL; 619 continue; 620 } 621 622 tp->ht_opaque = devp; 623 devp->hd_task = tp; 624 break; 625 } 626 627 spin_unlock(&hpet_lock); 628 spin_unlock_irq(&hpet_task_lock); 629 630 if (tp->ht_opaque) 631 return 0; 632 else 633 return -EBUSY; 634 } 635 636 static inline int hpet_tpcheck(struct hpet_task *tp) 637 { 638 struct hpet_dev *devp; 639 struct hpets *hpetp; 640 641 devp = tp->ht_opaque; 642 643 if (!devp) 644 return -ENXIO; 645 646 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 647 if (devp >= hpetp->hp_dev 648 && devp < (hpetp->hp_dev + hpetp->hp_ntimer) 649 && devp->hd_hpet == hpetp->hp_hpet) 650 return 0; 651 652 return -ENXIO; 653 } 654 655 int hpet_unregister(struct hpet_task *tp) 656 { 657 struct hpet_dev *devp; 658 struct hpet_timer __iomem *timer; 659 int err; 660 661 if ((err = hpet_tpcheck(tp))) 662 return err; 663 664 spin_lock_irq(&hpet_task_lock); 665 spin_lock(&hpet_lock); 666 667 devp = tp->ht_opaque; 668 if (devp->hd_task != tp) { 669 spin_unlock(&hpet_lock); 670 spin_unlock_irq(&hpet_task_lock); 671 return -ENXIO; 672 } 673 674 timer = devp->hd_timer; 675 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 676 &timer->hpet_config); 677 devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC); 678 devp->hd_task = NULL; 679 spin_unlock(&hpet_lock); 680 spin_unlock_irq(&hpet_task_lock); 681 682 return 0; 683 } 684 685 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg) 686 { 687 struct hpet_dev *devp; 688 int err; 689 690 if ((err = hpet_tpcheck(tp))) 691 return err; 692 693 spin_lock_irq(&hpet_lock); 694 devp = tp->ht_opaque; 695 if (devp->hd_task != tp) { 696 spin_unlock_irq(&hpet_lock); 697 return -ENXIO; 698 } 699 spin_unlock_irq(&hpet_lock); 700 return hpet_ioctl_common(devp, cmd, arg, 1); 701 } 702 703 static ctl_table hpet_table[] = { 704 { 705 .ctl_name = 1, 706 .procname = "max-user-freq", 707 .data = &hpet_max_freq, 708 .maxlen = sizeof(int), 709 .mode = 0644, 710 .proc_handler = &proc_dointvec, 711 }, 712 {.ctl_name = 0} 713 }; 714 715 static ctl_table hpet_root[] = { 716 { 717 .ctl_name = 1, 718 .procname = "hpet", 719 .maxlen = 0, 720 .mode = 0555, 721 .child = hpet_table, 722 }, 723 {.ctl_name = 0} 724 }; 725 726 static ctl_table dev_root[] = { 727 { 728 .ctl_name = CTL_DEV, 729 .procname = "dev", 730 .maxlen = 0, 731 .mode = 0555, 732 .child = hpet_root, 733 }, 734 {.ctl_name = 0} 735 }; 736 737 static struct ctl_table_header *sysctl_header; 738 739 static void hpet_register_interpolator(struct hpets *hpetp) 740 { 741 #ifdef CONFIG_TIME_INTERPOLATION 742 struct time_interpolator *ti; 743 744 ti = kzalloc(sizeof(*ti), GFP_KERNEL); 745 if (!ti) 746 return; 747 748 ti->source = TIME_SOURCE_MMIO64; 749 ti->shift = 10; 750 ti->addr = &hpetp->hp_hpet->hpet_mc; 751 ti->frequency = hpetp->hp_tick_freq; 752 ti->drift = HPET_DRIFT; 753 ti->mask = -1; 754 755 hpetp->hp_interpolator = ti; 756 register_time_interpolator(ti); 757 #endif 758 } 759 760 /* 761 * Adjustment for when arming the timer with 762 * initial conditions. That is, main counter 763 * ticks expired before interrupts are enabled. 764 */ 765 #define TICK_CALIBRATE (1000UL) 766 767 static unsigned long hpet_calibrate(struct hpets *hpetp) 768 { 769 struct hpet_timer __iomem *timer = NULL; 770 unsigned long t, m, count, i, flags, start; 771 struct hpet_dev *devp; 772 int j; 773 struct hpet __iomem *hpet; 774 775 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 776 if ((devp->hd_flags & HPET_OPEN) == 0) { 777 timer = devp->hd_timer; 778 break; 779 } 780 781 if (!timer) 782 return 0; 783 784 hpet = hpetp->hp_hpet; 785 t = read_counter(&timer->hpet_compare); 786 787 i = 0; 788 count = hpet_time_div(hpetp, TICK_CALIBRATE); 789 790 local_irq_save(flags); 791 792 start = read_counter(&hpet->hpet_mc); 793 794 do { 795 m = read_counter(&hpet->hpet_mc); 796 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 797 } while (i++, (m - start) < count); 798 799 local_irq_restore(flags); 800 801 return (m - start) / i; 802 } 803 804 int hpet_alloc(struct hpet_data *hdp) 805 { 806 u64 cap, mcfg; 807 struct hpet_dev *devp; 808 u32 i, ntimer; 809 struct hpets *hpetp; 810 size_t siz; 811 struct hpet __iomem *hpet; 812 static struct hpets *last = NULL; 813 unsigned long period; 814 unsigned long long temp; 815 816 /* 817 * hpet_alloc can be called by platform dependent code. 818 * If platform dependent code has allocated the hpet that 819 * ACPI has also reported, then we catch it here. 820 */ 821 if (hpet_is_known(hdp)) { 822 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 823 __FUNCTION__); 824 return 0; 825 } 826 827 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 828 sizeof(struct hpet_dev)); 829 830 hpetp = kzalloc(siz, GFP_KERNEL); 831 832 if (!hpetp) 833 return -ENOMEM; 834 835 hpetp->hp_which = hpet_nhpet++; 836 hpetp->hp_hpet = hdp->hd_address; 837 hpetp->hp_hpet_phys = hdp->hd_phys_address; 838 839 hpetp->hp_ntimer = hdp->hd_nirqs; 840 841 for (i = 0; i < hdp->hd_nirqs; i++) 842 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 843 844 hpet = hpetp->hp_hpet; 845 846 cap = readq(&hpet->hpet_cap); 847 848 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 849 850 if (hpetp->hp_ntimer != ntimer) { 851 printk(KERN_WARNING "hpet: number irqs doesn't agree" 852 " with number of timers\n"); 853 kfree(hpetp); 854 return -ENODEV; 855 } 856 857 if (last) 858 last->hp_next = hpetp; 859 else 860 hpets = hpetp; 861 862 last = hpetp; 863 864 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 865 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 866 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 867 temp += period >> 1; /* round */ 868 do_div(temp, period); 869 hpetp->hp_tick_freq = temp; /* ticks per second */ 870 871 printk(KERN_INFO "hpet%d: at MMIO 0x%lx (virtual 0x%p), IRQ%s", 872 hpetp->hp_which, hdp->hd_phys_address, hdp->hd_address, 873 hpetp->hp_ntimer > 1 ? "s" : ""); 874 for (i = 0; i < hpetp->hp_ntimer; i++) 875 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 876 printk("\n"); 877 878 printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n", 879 hpetp->hp_which, hpetp->hp_ntimer, 880 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq); 881 882 mcfg = readq(&hpet->hpet_config); 883 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 884 write_counter(0L, &hpet->hpet_mc); 885 mcfg |= HPET_ENABLE_CNF_MASK; 886 writeq(mcfg, &hpet->hpet_config); 887 } 888 889 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 890 struct hpet_timer __iomem *timer; 891 892 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 893 894 devp->hd_hpets = hpetp; 895 devp->hd_hpet = hpet; 896 devp->hd_timer = timer; 897 898 /* 899 * If the timer was reserved by platform code, 900 * then make timer unavailable for opens. 901 */ 902 if (hdp->hd_state & (1 << i)) { 903 devp->hd_flags = HPET_OPEN; 904 continue; 905 } 906 907 init_waitqueue_head(&devp->hd_waitqueue); 908 } 909 910 hpetp->hp_delta = hpet_calibrate(hpetp); 911 hpet_register_interpolator(hpetp); 912 913 return 0; 914 } 915 916 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 917 { 918 struct hpet_data *hdp; 919 acpi_status status; 920 struct acpi_resource_address64 addr; 921 922 hdp = data; 923 924 status = acpi_resource_to_address64(res, &addr); 925 926 if (ACPI_SUCCESS(status)) { 927 hdp->hd_phys_address = addr.minimum; 928 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 929 930 if (hpet_is_known(hdp)) { 931 printk(KERN_DEBUG "%s: 0x%lx is busy\n", 932 __FUNCTION__, hdp->hd_phys_address); 933 iounmap(hdp->hd_address); 934 return -EBUSY; 935 } 936 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 937 struct acpi_resource_fixed_memory32 *fixmem32; 938 939 fixmem32 = &res->data.fixed_memory32; 940 if (!fixmem32) 941 return -EINVAL; 942 943 hdp->hd_phys_address = fixmem32->address; 944 hdp->hd_address = ioremap(fixmem32->address, 945 HPET_RANGE_SIZE); 946 947 if (hpet_is_known(hdp)) { 948 printk(KERN_DEBUG "%s: 0x%lx is busy\n", 949 __FUNCTION__, hdp->hd_phys_address); 950 iounmap(hdp->hd_address); 951 return -EBUSY; 952 } 953 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 954 struct acpi_resource_extended_irq *irqp; 955 int i, irq; 956 957 irqp = &res->data.extended_irq; 958 959 for (i = 0; i < irqp->interrupt_count; i++) { 960 irq = acpi_register_gsi(irqp->interrupts[i], 961 irqp->triggering, irqp->polarity); 962 if (irq < 0) 963 return AE_ERROR; 964 965 hdp->hd_irq[hdp->hd_nirqs] = irq; 966 hdp->hd_nirqs++; 967 } 968 } 969 970 return AE_OK; 971 } 972 973 static int hpet_acpi_add(struct acpi_device *device) 974 { 975 acpi_status result; 976 struct hpet_data data; 977 978 memset(&data, 0, sizeof(data)); 979 980 result = 981 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 982 hpet_resources, &data); 983 984 if (ACPI_FAILURE(result)) 985 return -ENODEV; 986 987 if (!data.hd_address || !data.hd_nirqs) { 988 printk("%s: no address or irqs in _CRS\n", __FUNCTION__); 989 return -ENODEV; 990 } 991 992 return hpet_alloc(&data); 993 } 994 995 static int hpet_acpi_remove(struct acpi_device *device, int type) 996 { 997 /* XXX need to unregister interpolator, dealloc mem, etc */ 998 return -EINVAL; 999 } 1000 1001 static struct acpi_driver hpet_acpi_driver = { 1002 .name = "hpet", 1003 .ids = "PNP0103", 1004 .ops = { 1005 .add = hpet_acpi_add, 1006 .remove = hpet_acpi_remove, 1007 }, 1008 }; 1009 1010 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1011 1012 static int __init hpet_init(void) 1013 { 1014 int result; 1015 1016 result = misc_register(&hpet_misc); 1017 if (result < 0) 1018 return -ENODEV; 1019 1020 sysctl_header = register_sysctl_table(dev_root, 0); 1021 1022 result = acpi_bus_register_driver(&hpet_acpi_driver); 1023 if (result < 0) { 1024 if (sysctl_header) 1025 unregister_sysctl_table(sysctl_header); 1026 misc_deregister(&hpet_misc); 1027 return result; 1028 } 1029 1030 return 0; 1031 } 1032 1033 static void __exit hpet_exit(void) 1034 { 1035 acpi_bus_unregister_driver(&hpet_acpi_driver); 1036 1037 if (sysctl_header) 1038 unregister_sysctl_table(sysctl_header); 1039 misc_deregister(&hpet_misc); 1040 1041 return; 1042 } 1043 1044 module_init(hpet_init); 1045 module_exit(hpet_exit); 1046 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1047 MODULE_LICENSE("GPL"); 1048