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 70static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 71 72/* This clocksource driver currently only works on ia64 */ 73#ifdef CONFIG_IA64 74static void __iomem *hpet_mctr; 75 76static cycle_t read_hpet(struct clocksource *cs) 77{ 78 return (cycle_t)read_counter((void __iomem *)hpet_mctr); 79} 80 81static 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}; 90static struct clocksource *hpet_clocksource; 91#endif 92 93/* A lock for concurrent access by app and isr hpet activity. */ 94static DEFINE_SPINLOCK(hpet_lock); 95 96#define HPET_DEV_NAME (7) 97 98struct 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 112struct 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 124static 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 133static 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 140static 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 147static 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 185static 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 } 231 232 if (irq < HPET_MAX_IRQ) { 233 spin_lock_irq(&hpet_lock); 234 v = readl(&timer->hpet_config); 235 v |= irq << Tn_INT_ROUTE_CNF_SHIFT; 236 writel(v, &timer->hpet_config); 237 devp->hd_hdwirq = gsi; 238 spin_unlock_irq(&hpet_lock); 239 } 240 return; 241} 242 243static int hpet_open(struct inode *inode, struct file *file) 244{ 245 struct hpet_dev *devp; 246 struct hpets *hpetp; 247 int i; 248 249 if (file->f_mode & FMODE_WRITE) 250 return -EINVAL; 251 252 lock_kernel(); 253 spin_lock_irq(&hpet_lock); 254 255 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 256 for (i = 0; i < hpetp->hp_ntimer; i++) 257 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) 258 continue; 259 else { 260 devp = &hpetp->hp_dev[i]; 261 break; 262 } 263 264 if (!devp) { 265 spin_unlock_irq(&hpet_lock); 266 unlock_kernel(); 267 return -EBUSY; 268 } 269 270 file->private_data = devp; 271 devp->hd_irqdata = 0; 272 devp->hd_flags |= HPET_OPEN; 273 spin_unlock_irq(&hpet_lock); 274 unlock_kernel(); 275 276 hpet_timer_set_irq(devp); 277 278 return 0; 279} 280 281static ssize_t 282hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 283{ 284 DECLARE_WAITQUEUE(wait, current); 285 unsigned long data; 286 ssize_t retval; 287 struct hpet_dev *devp; 288 289 devp = file->private_data; 290 if (!devp->hd_ireqfreq) 291 return -EIO; 292 293 if (count < sizeof(unsigned long)) 294 return -EINVAL; 295 296 add_wait_queue(&devp->hd_waitqueue, &wait); 297 298 for ( ; ; ) { 299 set_current_state(TASK_INTERRUPTIBLE); 300 301 spin_lock_irq(&hpet_lock); 302 data = devp->hd_irqdata; 303 devp->hd_irqdata = 0; 304 spin_unlock_irq(&hpet_lock); 305 306 if (data) 307 break; 308 else if (file->f_flags & O_NONBLOCK) { 309 retval = -EAGAIN; 310 goto out; 311 } else if (signal_pending(current)) { 312 retval = -ERESTARTSYS; 313 goto out; 314 } 315 schedule(); 316 } 317 318 retval = put_user(data, (unsigned long __user *)buf); 319 if (!retval) 320 retval = sizeof(unsigned long); 321out: 322 __set_current_state(TASK_RUNNING); 323 remove_wait_queue(&devp->hd_waitqueue, &wait); 324 325 return retval; 326} 327 328static unsigned int hpet_poll(struct file *file, poll_table * wait) 329{ 330 unsigned long v; 331 struct hpet_dev *devp; 332 333 devp = file->private_data; 334 335 if (!devp->hd_ireqfreq) 336 return 0; 337 338 poll_wait(file, &devp->hd_waitqueue, wait); 339 340 spin_lock_irq(&hpet_lock); 341 v = devp->hd_irqdata; 342 spin_unlock_irq(&hpet_lock); 343 344 if (v != 0) 345 return POLLIN | POLLRDNORM; 346 347 return 0; 348} 349 350static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 351{ 352#ifdef CONFIG_HPET_MMAP 353 struct hpet_dev *devp; 354 unsigned long addr; 355 356 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 357 return -EINVAL; 358 359 devp = file->private_data; 360 addr = devp->hd_hpets->hp_hpet_phys; 361 362 if (addr & (PAGE_SIZE - 1)) 363 return -ENOSYS; 364 365 vma->vm_flags |= VM_IO; 366 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 367 368 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 369 PAGE_SIZE, vma->vm_page_prot)) { 370 printk(KERN_ERR "%s: io_remap_pfn_range failed\n", 371 __func__); 372 return -EAGAIN; 373 } 374 375 return 0; 376#else 377 return -ENOSYS; 378#endif 379} 380 381static int hpet_fasync(int fd, struct file *file, int on) 382{ 383 struct hpet_dev *devp; 384 385 devp = file->private_data; 386 387 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 388 return 0; 389 else 390 return -EIO; 391} 392 393static int hpet_release(struct inode *inode, struct file *file) 394{ 395 struct hpet_dev *devp; 396 struct hpet_timer __iomem *timer; 397 int irq = 0; 398 399 devp = file->private_data; 400 timer = devp->hd_timer; 401 402 spin_lock_irq(&hpet_lock); 403 404 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 405 &timer->hpet_config); 406 407 irq = devp->hd_irq; 408 devp->hd_irq = 0; 409 410 devp->hd_ireqfreq = 0; 411 412 if (devp->hd_flags & HPET_PERIODIC 413 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 414 unsigned long v; 415 416 v = readq(&timer->hpet_config); 417 v ^= Tn_TYPE_CNF_MASK; 418 writeq(v, &timer->hpet_config); 419 } 420 421 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 422 spin_unlock_irq(&hpet_lock); 423 424 if (irq) 425 free_irq(irq, devp); 426 427 file->private_data = NULL; 428 return 0; 429} 430 431static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 432 433static long hpet_ioctl(struct file *file, unsigned int cmd, 434 unsigned long arg) 435{ 436 struct hpet_dev *devp; 437 int ret; 438 439 devp = file->private_data; 440 lock_kernel(); 441 ret = hpet_ioctl_common(devp, cmd, arg, 0); 442 unlock_kernel(); 443 444 return ret; 445} 446 447static int hpet_ioctl_ieon(struct hpet_dev *devp) 448{ 449 struct hpet_timer __iomem *timer; 450 struct hpet __iomem *hpet; 451 struct hpets *hpetp; 452 int irq; 453 unsigned long g, v, t, m; 454 unsigned long flags, isr; 455 456 timer = devp->hd_timer; 457 hpet = devp->hd_hpet; 458 hpetp = devp->hd_hpets; 459 460 if (!devp->hd_ireqfreq) 461 return -EIO; 462 463 spin_lock_irq(&hpet_lock); 464 465 if (devp->hd_flags & HPET_IE) { 466 spin_unlock_irq(&hpet_lock); 467 return -EBUSY; 468 } 469 470 devp->hd_flags |= HPET_IE; 471 472 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 473 devp->hd_flags |= HPET_SHARED_IRQ; 474 spin_unlock_irq(&hpet_lock); 475 476 irq = devp->hd_hdwirq; 477 478 if (irq) { 479 unsigned long irq_flags; 480 481 if (devp->hd_flags & HPET_SHARED_IRQ) { 482 /* 483 * To prevent the interrupt handler from seeing an 484 * unwanted interrupt status bit, program the timer 485 * so that it will not fire in the near future ... 486 */ 487 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, 488 &timer->hpet_config); 489 write_counter(read_counter(&hpet->hpet_mc), 490 &timer->hpet_compare); 491 /* ... and clear any left-over status. */ 492 isr = 1 << (devp - devp->hd_hpets->hp_dev); 493 writel(isr, &hpet->hpet_isr); 494 } 495 496 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 497 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 498 ? IRQF_SHARED : IRQF_DISABLED; 499 if (request_irq(irq, hpet_interrupt, irq_flags, 500 devp->hd_name, (void *)devp)) { 501 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 502 irq = 0; 503 } 504 } 505 506 if (irq == 0) { 507 spin_lock_irq(&hpet_lock); 508 devp->hd_flags ^= HPET_IE; 509 spin_unlock_irq(&hpet_lock); 510 return -EIO; 511 } 512 513 devp->hd_irq = irq; 514 t = devp->hd_ireqfreq; 515 v = readq(&timer->hpet_config); 516 517 /* 64-bit comparators are not yet supported through the ioctls, 518 * so force this into 32-bit mode if it supports both modes 519 */ 520 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; 521 522 if (devp->hd_flags & HPET_PERIODIC) { 523 g |= Tn_TYPE_CNF_MASK; 524 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; 525 writeq(v, &timer->hpet_config); 526 local_irq_save(flags); 527 528 /* 529 * NOTE: First we modify the hidden accumulator 530 * register supported by periodic-capable comparators. 531 * We never want to modify the (single) counter; that 532 * would affect all the comparators. The value written 533 * is the counter value when the first interrupt is due. 534 */ 535 m = read_counter(&hpet->hpet_mc); 536 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 537 /* 538 * Then we modify the comparator, indicating the period 539 * for subsequent interrupt. 540 */ 541 write_counter(t, &timer->hpet_compare); 542 } else { 543 local_irq_save(flags); 544 m = read_counter(&hpet->hpet_mc); 545 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 546 } 547 548 if (devp->hd_flags & HPET_SHARED_IRQ) { 549 isr = 1 << (devp - devp->hd_hpets->hp_dev); 550 writel(isr, &hpet->hpet_isr); 551 } 552 writeq(g, &timer->hpet_config); 553 local_irq_restore(flags); 554 555 return 0; 556} 557 558/* converts Hz to number of timer ticks */ 559static inline unsigned long hpet_time_div(struct hpets *hpets, 560 unsigned long dis) 561{ 562 unsigned long long m; 563 564 m = hpets->hp_tick_freq + (dis >> 1); 565 do_div(m, dis); 566 return (unsigned long)m; 567} 568 569static int 570hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 571{ 572 struct hpet_timer __iomem *timer; 573 struct hpet __iomem *hpet; 574 struct hpets *hpetp; 575 int err; 576 unsigned long v; 577 578 switch (cmd) { 579 case HPET_IE_OFF: 580 case HPET_INFO: 581 case HPET_EPI: 582 case HPET_DPI: 583 case HPET_IRQFREQ: 584 timer = devp->hd_timer; 585 hpet = devp->hd_hpet; 586 hpetp = devp->hd_hpets; 587 break; 588 case HPET_IE_ON: 589 return hpet_ioctl_ieon(devp); 590 default: 591 return -EINVAL; 592 } 593 594 err = 0; 595 596 switch (cmd) { 597 case HPET_IE_OFF: 598 if ((devp->hd_flags & HPET_IE) == 0) 599 break; 600 v = readq(&timer->hpet_config); 601 v &= ~Tn_INT_ENB_CNF_MASK; 602 writeq(v, &timer->hpet_config); 603 if (devp->hd_irq) { 604 free_irq(devp->hd_irq, devp); 605 devp->hd_irq = 0; 606 } 607 devp->hd_flags ^= HPET_IE; 608 break; 609 case HPET_INFO: 610 { 611 struct hpet_info info; 612 613 if (devp->hd_ireqfreq) 614 info.hi_ireqfreq = 615 hpet_time_div(hpetp, devp->hd_ireqfreq); 616 else 617 info.hi_ireqfreq = 0; 618 info.hi_flags = 619 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 620 info.hi_hpet = hpetp->hp_which; 621 info.hi_timer = devp - hpetp->hp_dev; 622 if (kernel) 623 memcpy((void *)arg, &info, sizeof(info)); 624 else 625 if (copy_to_user((void __user *)arg, &info, 626 sizeof(info))) 627 err = -EFAULT; 628 break; 629 } 630 case HPET_EPI: 631 v = readq(&timer->hpet_config); 632 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 633 err = -ENXIO; 634 break; 635 } 636 devp->hd_flags |= HPET_PERIODIC; 637 break; 638 case HPET_DPI: 639 v = readq(&timer->hpet_config); 640 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 641 err = -ENXIO; 642 break; 643 } 644 if (devp->hd_flags & HPET_PERIODIC && 645 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 646 v = readq(&timer->hpet_config); 647 v ^= Tn_TYPE_CNF_MASK; 648 writeq(v, &timer->hpet_config); 649 } 650 devp->hd_flags &= ~HPET_PERIODIC; 651 break; 652 case HPET_IRQFREQ: 653 if (!kernel && (arg > hpet_max_freq) && 654 !capable(CAP_SYS_RESOURCE)) { 655 err = -EACCES; 656 break; 657 } 658 659 if (!arg) { 660 err = -EINVAL; 661 break; 662 } 663 664 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 665 } 666 667 return err; 668} 669 670static const struct file_operations hpet_fops = { 671 .owner = THIS_MODULE, 672 .llseek = no_llseek, 673 .read = hpet_read, 674 .poll = hpet_poll, 675 .unlocked_ioctl = hpet_ioctl, 676 .open = hpet_open, 677 .release = hpet_release, 678 .fasync = hpet_fasync, 679 .mmap = hpet_mmap, 680}; 681 682static int hpet_is_known(struct hpet_data *hdp) 683{ 684 struct hpets *hpetp; 685 686 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 687 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 688 return 1; 689 690 return 0; 691} 692 693static ctl_table hpet_table[] = { 694 { 695 .procname = "max-user-freq", 696 .data = &hpet_max_freq, 697 .maxlen = sizeof(int), 698 .mode = 0644, 699 .proc_handler = proc_dointvec, 700 }, 701 {} 702}; 703 704static ctl_table hpet_root[] = { 705 { 706 .procname = "hpet", 707 .maxlen = 0, 708 .mode = 0555, 709 .child = hpet_table, 710 }, 711 {} 712}; 713 714static ctl_table dev_root[] = { 715 { 716 .procname = "dev", 717 .maxlen = 0, 718 .mode = 0555, 719 .child = hpet_root, 720 }, 721 {} 722}; 723 724static struct ctl_table_header *sysctl_header; 725 726/* 727 * Adjustment for when arming the timer with 728 * initial conditions. That is, main counter 729 * ticks expired before interrupts are enabled. 730 */ 731#define TICK_CALIBRATE (1000UL) 732 733static unsigned long __hpet_calibrate(struct hpets *hpetp) 734{ 735 struct hpet_timer __iomem *timer = NULL; 736 unsigned long t, m, count, i, flags, start; 737 struct hpet_dev *devp; 738 int j; 739 struct hpet __iomem *hpet; 740 741 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 742 if ((devp->hd_flags & HPET_OPEN) == 0) { 743 timer = devp->hd_timer; 744 break; 745 } 746 747 if (!timer) 748 return 0; 749 750 hpet = hpetp->hp_hpet; 751 t = read_counter(&timer->hpet_compare); 752 753 i = 0; 754 count = hpet_time_div(hpetp, TICK_CALIBRATE); 755 756 local_irq_save(flags); 757 758 start = read_counter(&hpet->hpet_mc); 759 760 do { 761 m = read_counter(&hpet->hpet_mc); 762 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 763 } while (i++, (m - start) < count); 764 765 local_irq_restore(flags); 766 767 return (m - start) / i; 768} 769 770static unsigned long hpet_calibrate(struct hpets *hpetp) 771{ 772 unsigned long ret = -1; 773 unsigned long tmp; 774 775 /* 776 * Try to calibrate until return value becomes stable small value. 777 * If SMI interruption occurs in calibration loop, the return value 778 * will be big. This avoids its impact. 779 */ 780 for ( ; ; ) { 781 tmp = __hpet_calibrate(hpetp); 782 if (ret <= tmp) 783 break; 784 ret = tmp; 785 } 786 787 return ret; 788} 789 790int hpet_alloc(struct hpet_data *hdp) 791{ 792 u64 cap, mcfg; 793 struct hpet_dev *devp; 794 u32 i, ntimer; 795 struct hpets *hpetp; 796 size_t siz; 797 struct hpet __iomem *hpet; 798 static struct hpets *last = NULL; 799 unsigned long period; 800 unsigned long long temp; 801 u32 remainder; 802 803 /* 804 * hpet_alloc can be called by platform dependent code. 805 * If platform dependent code has allocated the hpet that 806 * ACPI has also reported, then we catch it here. 807 */ 808 if (hpet_is_known(hdp)) { 809 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 810 __func__); 811 return 0; 812 } 813 814 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 815 sizeof(struct hpet_dev)); 816 817 hpetp = kzalloc(siz, GFP_KERNEL); 818 819 if (!hpetp) 820 return -ENOMEM; 821 822 hpetp->hp_which = hpet_nhpet++; 823 hpetp->hp_hpet = hdp->hd_address; 824 hpetp->hp_hpet_phys = hdp->hd_phys_address; 825 826 hpetp->hp_ntimer = hdp->hd_nirqs; 827 828 for (i = 0; i < hdp->hd_nirqs; i++) 829 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 830 831 hpet = hpetp->hp_hpet; 832 833 cap = readq(&hpet->hpet_cap); 834 835 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 836 837 if (hpetp->hp_ntimer != ntimer) { 838 printk(KERN_WARNING "hpet: number irqs doesn't agree" 839 " with number of timers\n"); 840 kfree(hpetp); 841 return -ENODEV; 842 } 843 844 if (last) 845 last->hp_next = hpetp; 846 else 847 hpets = hpetp; 848 849 last = hpetp; 850 851 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 852 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 853 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 854 temp += period >> 1; /* round */ 855 do_div(temp, period); 856 hpetp->hp_tick_freq = temp; /* ticks per second */ 857 858 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 859 hpetp->hp_which, hdp->hd_phys_address, 860 hpetp->hp_ntimer > 1 ? "s" : ""); 861 for (i = 0; i < hpetp->hp_ntimer; i++) 862 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 863 printk("\n"); 864 865 temp = hpetp->hp_tick_freq; 866 remainder = do_div(temp, 1000000); 867 printk(KERN_INFO 868 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", 869 hpetp->hp_which, hpetp->hp_ntimer, 870 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, 871 (unsigned) temp, remainder); 872 873 mcfg = readq(&hpet->hpet_config); 874 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 875 write_counter(0L, &hpet->hpet_mc); 876 mcfg |= HPET_ENABLE_CNF_MASK; 877 writeq(mcfg, &hpet->hpet_config); 878 } 879 880 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 881 struct hpet_timer __iomem *timer; 882 883 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 884 885 devp->hd_hpets = hpetp; 886 devp->hd_hpet = hpet; 887 devp->hd_timer = timer; 888 889 /* 890 * If the timer was reserved by platform code, 891 * then make timer unavailable for opens. 892 */ 893 if (hdp->hd_state & (1 << i)) { 894 devp->hd_flags = HPET_OPEN; 895 continue; 896 } 897 898 init_waitqueue_head(&devp->hd_waitqueue); 899 } 900 901 hpetp->hp_delta = hpet_calibrate(hpetp); 902 903/* This clocksource driver currently only works on ia64 */ 904#ifdef CONFIG_IA64 905 if (!hpet_clocksource) { 906 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 907 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); 908 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, 909 clocksource_hpet.shift); 910 clocksource_register(&clocksource_hpet); 911 hpetp->hp_clocksource = &clocksource_hpet; 912 hpet_clocksource = &clocksource_hpet; 913 } 914#endif 915 916 return 0; 917} 918 919static acpi_status hpet_resources(struct acpi_resource *res, void *data) 920{ 921 struct hpet_data *hdp; 922 acpi_status status; 923 struct acpi_resource_address64 addr; 924 925 hdp = data; 926 927 status = acpi_resource_to_address64(res, &addr); 928 929 if (ACPI_SUCCESS(status)) { 930 hdp->hd_phys_address = addr.minimum; 931 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 932 933 if (hpet_is_known(hdp)) { 934 iounmap(hdp->hd_address); 935 return AE_ALREADY_EXISTS; 936 } 937 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 938 struct acpi_resource_fixed_memory32 *fixmem32; 939 940 fixmem32 = &res->data.fixed_memory32; 941 if (!fixmem32) 942 return AE_NO_MEMORY; 943 944 hdp->hd_phys_address = fixmem32->address; 945 hdp->hd_address = ioremap(fixmem32->address, 946 HPET_RANGE_SIZE); 947 948 if (hpet_is_known(hdp)) { 949 iounmap(hdp->hd_address); 950 return AE_ALREADY_EXISTS; 951 } 952 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 953 struct acpi_resource_extended_irq *irqp; 954 int i, irq; 955 956 irqp = &res->data.extended_irq; 957 958 for (i = 0; i < irqp->interrupt_count; i++) { 959 irq = acpi_register_gsi(NULL, irqp->interrupts[i], 960 irqp->triggering, irqp->polarity); 961 if (irq < 0) 962 return AE_ERROR; 963 964 hdp->hd_irq[hdp->hd_nirqs] = irq; 965 hdp->hd_nirqs++; 966 } 967 } 968 969 return AE_OK; 970} 971 972static int hpet_acpi_add(struct acpi_device *device) 973{ 974 acpi_status result; 975 struct hpet_data data; 976 977 memset(&data, 0, sizeof(data)); 978 979 result = 980 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 981 hpet_resources, &data); 982 983 if (ACPI_FAILURE(result)) 984 return -ENODEV; 985 986 if (!data.hd_address || !data.hd_nirqs) { 987 if (data.hd_address) 988 iounmap(data.hd_address); 989 printk("%s: no address or irqs in _CRS\n", __func__); 990 return -ENODEV; 991 } 992 993 return hpet_alloc(&data); 994} 995 996static int hpet_acpi_remove(struct acpi_device *device, int type) 997{ 998 return -EINVAL; 999} 1000 1001static const struct acpi_device_id hpet_device_ids[] = { 1002 {"PNP0103", 0}, 1003 {"", 0}, 1004}; 1005MODULE_DEVICE_TABLE(acpi, hpet_device_ids); 1006 1007static struct acpi_driver hpet_acpi_driver = { 1008 .name = "hpet", 1009 .ids = hpet_device_ids, 1010 .ops = { 1011 .add = hpet_acpi_add, 1012 .remove = hpet_acpi_remove, 1013 }, 1014}; 1015 1016static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1017 1018static int __init hpet_init(void) 1019{ 1020 int result; 1021 1022 result = misc_register(&hpet_misc); 1023 if (result < 0) 1024 return -ENODEV; 1025 1026 sysctl_header = register_sysctl_table(dev_root); 1027 1028 result = acpi_bus_register_driver(&hpet_acpi_driver); 1029 if (result < 0) { 1030 if (sysctl_header) 1031 unregister_sysctl_table(sysctl_header); 1032 misc_deregister(&hpet_misc); 1033 return result; 1034 } 1035 1036 return 0; 1037} 1038 1039static void __exit hpet_exit(void) 1040{ 1041 acpi_bus_unregister_driver(&hpet_acpi_driver); 1042 1043 if (sysctl_header) 1044 unregister_sysctl_table(sysctl_header); 1045 misc_deregister(&hpet_misc); 1046 1047 return; 1048} 1049 1050module_init(hpet_init); 1051module_exit(hpet_exit); 1052MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1053MODULE_LICENSE("GPL"); 1054