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 35 #include <asm/current.h> 36 #include <asm/uaccess.h> 37 #include <asm/system.h> 38 #include <asm/io.h> 39 #include <asm/irq.h> 40 #include <asm/div64.h> 41 42 #include <linux/acpi.h> 43 #include <acpi/acpi_bus.h> 44 #include <linux/hpet.h> 45 46 /* 47 * The High Precision Event Timer driver. 48 * This driver is closely modelled after the rtc.c driver. 49 * http://www.intel.com/hardwaredesign/hpetspec_1.pdf 50 */ 51 #define HPET_USER_FREQ (64) 52 #define HPET_DRIFT (500) 53 54 #define HPET_RANGE_SIZE 1024 /* from HPET spec */ 55 56 57 /* WARNING -- don't get confused. These macros are never used 58 * to write the (single) counter, and rarely to read it. 59 * They're badly named; to fix, someday. 60 */ 61 #if BITS_PER_LONG == 64 62 #define write_counter(V, MC) writeq(V, MC) 63 #define read_counter(MC) readq(MC) 64 #else 65 #define write_counter(V, MC) writel(V, MC) 66 #define read_counter(MC) readl(MC) 67 #endif 68 69 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 70 71 /* This clocksource driver currently only works on ia64 */ 72 #ifdef CONFIG_IA64 73 static void __iomem *hpet_mctr; 74 75 static cycle_t read_hpet(struct clocksource *cs) 76 { 77 return (cycle_t)read_counter((void __iomem *)hpet_mctr); 78 } 79 80 static struct clocksource clocksource_hpet = { 81 .name = "hpet", 82 .rating = 250, 83 .read = read_hpet, 84 .mask = CLOCKSOURCE_MASK(64), 85 .mult = 0, /* to be calculated */ 86 .shift = 10, 87 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 88 }; 89 static struct clocksource *hpet_clocksource; 90 #endif 91 92 /* A lock for concurrent access by app and isr hpet activity. */ 93 static DEFINE_SPINLOCK(hpet_lock); 94 95 #define HPET_DEV_NAME (7) 96 97 struct hpet_dev { 98 struct hpets *hd_hpets; 99 struct hpet __iomem *hd_hpet; 100 struct hpet_timer __iomem *hd_timer; 101 unsigned long hd_ireqfreq; 102 unsigned long hd_irqdata; 103 wait_queue_head_t hd_waitqueue; 104 struct fasync_struct *hd_async_queue; 105 unsigned int hd_flags; 106 unsigned int hd_irq; 107 unsigned int hd_hdwirq; 108 char hd_name[HPET_DEV_NAME]; 109 }; 110 111 struct hpets { 112 struct hpets *hp_next; 113 struct hpet __iomem *hp_hpet; 114 unsigned long hp_hpet_phys; 115 struct clocksource *hp_clocksource; 116 unsigned long long hp_tick_freq; 117 unsigned long hp_delta; 118 unsigned int hp_ntimer; 119 unsigned int hp_which; 120 struct hpet_dev hp_dev[1]; 121 }; 122 123 static struct hpets *hpets; 124 125 #define HPET_OPEN 0x0001 126 #define HPET_IE 0x0002 /* interrupt enabled */ 127 #define HPET_PERIODIC 0x0004 128 #define HPET_SHARED_IRQ 0x0008 129 130 131 #ifndef readq 132 static inline unsigned long long readq(void __iomem *addr) 133 { 134 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 135 } 136 #endif 137 138 #ifndef writeq 139 static inline void writeq(unsigned long long v, void __iomem *addr) 140 { 141 writel(v & 0xffffffff, addr); 142 writel(v >> 32, addr + 4); 143 } 144 #endif 145 146 static irqreturn_t hpet_interrupt(int irq, void *data) 147 { 148 struct hpet_dev *devp; 149 unsigned long isr; 150 151 devp = data; 152 isr = 1 << (devp - devp->hd_hpets->hp_dev); 153 154 if ((devp->hd_flags & HPET_SHARED_IRQ) && 155 !(isr & readl(&devp->hd_hpet->hpet_isr))) 156 return IRQ_NONE; 157 158 spin_lock(&hpet_lock); 159 devp->hd_irqdata++; 160 161 /* 162 * For non-periodic timers, increment the accumulator. 163 * This has the effect of treating non-periodic like periodic. 164 */ 165 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 166 unsigned long m, t; 167 168 t = devp->hd_ireqfreq; 169 m = read_counter(&devp->hd_timer->hpet_compare); 170 write_counter(t + m, &devp->hd_timer->hpet_compare); 171 } 172 173 if (devp->hd_flags & HPET_SHARED_IRQ) 174 writel(isr, &devp->hd_hpet->hpet_isr); 175 spin_unlock(&hpet_lock); 176 177 wake_up_interruptible(&devp->hd_waitqueue); 178 179 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 180 181 return IRQ_HANDLED; 182 } 183 184 static void hpet_timer_set_irq(struct hpet_dev *devp) 185 { 186 unsigned long v; 187 int irq, gsi; 188 struct hpet_timer __iomem *timer; 189 190 spin_lock_irq(&hpet_lock); 191 if (devp->hd_hdwirq) { 192 spin_unlock_irq(&hpet_lock); 193 return; 194 } 195 196 timer = devp->hd_timer; 197 198 /* we prefer level triggered mode */ 199 v = readl(&timer->hpet_config); 200 if (!(v & Tn_INT_TYPE_CNF_MASK)) { 201 v |= Tn_INT_TYPE_CNF_MASK; 202 writel(v, &timer->hpet_config); 203 } 204 spin_unlock_irq(&hpet_lock); 205 206 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> 207 Tn_INT_ROUTE_CAP_SHIFT; 208 209 /* 210 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by 211 * legacy device. In IO APIC mode, we skip all the legacy IRQS. 212 */ 213 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) 214 v &= ~0xf3df; 215 else 216 v &= ~0xffff; 217 218 for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ; 219 irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) { 220 221 if (irq >= nr_irqs) { 222 irq = HPET_MAX_IRQ; 223 break; 224 } 225 226 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, 227 ACPI_ACTIVE_LOW); 228 if (gsi > 0) 229 break; 230 231 /* FIXME: Setup interrupt source table */ 232 } 233 234 if (irq < HPET_MAX_IRQ) { 235 spin_lock_irq(&hpet_lock); 236 v = readl(&timer->hpet_config); 237 v |= irq << Tn_INT_ROUTE_CNF_SHIFT; 238 writel(v, &timer->hpet_config); 239 devp->hd_hdwirq = gsi; 240 spin_unlock_irq(&hpet_lock); 241 } 242 return; 243 } 244 245 static int hpet_open(struct inode *inode, struct file *file) 246 { 247 struct hpet_dev *devp; 248 struct hpets *hpetp; 249 int i; 250 251 if (file->f_mode & FMODE_WRITE) 252 return -EINVAL; 253 254 lock_kernel(); 255 spin_lock_irq(&hpet_lock); 256 257 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 258 for (i = 0; i < hpetp->hp_ntimer; i++) 259 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) 260 continue; 261 else { 262 devp = &hpetp->hp_dev[i]; 263 break; 264 } 265 266 if (!devp) { 267 spin_unlock_irq(&hpet_lock); 268 unlock_kernel(); 269 return -EBUSY; 270 } 271 272 file->private_data = devp; 273 devp->hd_irqdata = 0; 274 devp->hd_flags |= HPET_OPEN; 275 spin_unlock_irq(&hpet_lock); 276 unlock_kernel(); 277 278 hpet_timer_set_irq(devp); 279 280 return 0; 281 } 282 283 static ssize_t 284 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 285 { 286 DECLARE_WAITQUEUE(wait, current); 287 unsigned long data; 288 ssize_t retval; 289 struct hpet_dev *devp; 290 291 devp = file->private_data; 292 if (!devp->hd_ireqfreq) 293 return -EIO; 294 295 if (count < sizeof(unsigned long)) 296 return -EINVAL; 297 298 add_wait_queue(&devp->hd_waitqueue, &wait); 299 300 for ( ; ; ) { 301 set_current_state(TASK_INTERRUPTIBLE); 302 303 spin_lock_irq(&hpet_lock); 304 data = devp->hd_irqdata; 305 devp->hd_irqdata = 0; 306 spin_unlock_irq(&hpet_lock); 307 308 if (data) 309 break; 310 else if (file->f_flags & O_NONBLOCK) { 311 retval = -EAGAIN; 312 goto out; 313 } else if (signal_pending(current)) { 314 retval = -ERESTARTSYS; 315 goto out; 316 } 317 schedule(); 318 } 319 320 retval = put_user(data, (unsigned long __user *)buf); 321 if (!retval) 322 retval = sizeof(unsigned long); 323 out: 324 __set_current_state(TASK_RUNNING); 325 remove_wait_queue(&devp->hd_waitqueue, &wait); 326 327 return retval; 328 } 329 330 static unsigned int hpet_poll(struct file *file, poll_table * wait) 331 { 332 unsigned long v; 333 struct hpet_dev *devp; 334 335 devp = file->private_data; 336 337 if (!devp->hd_ireqfreq) 338 return 0; 339 340 poll_wait(file, &devp->hd_waitqueue, wait); 341 342 spin_lock_irq(&hpet_lock); 343 v = devp->hd_irqdata; 344 spin_unlock_irq(&hpet_lock); 345 346 if (v != 0) 347 return POLLIN | POLLRDNORM; 348 349 return 0; 350 } 351 352 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 353 { 354 #ifdef CONFIG_HPET_MMAP 355 struct hpet_dev *devp; 356 unsigned long addr; 357 358 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 359 return -EINVAL; 360 361 devp = file->private_data; 362 addr = devp->hd_hpets->hp_hpet_phys; 363 364 if (addr & (PAGE_SIZE - 1)) 365 return -ENOSYS; 366 367 vma->vm_flags |= VM_IO; 368 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 369 370 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 371 PAGE_SIZE, vma->vm_page_prot)) { 372 printk(KERN_ERR "%s: io_remap_pfn_range failed\n", 373 __func__); 374 return -EAGAIN; 375 } 376 377 return 0; 378 #else 379 return -ENOSYS; 380 #endif 381 } 382 383 static int hpet_fasync(int fd, struct file *file, int on) 384 { 385 struct hpet_dev *devp; 386 387 devp = file->private_data; 388 389 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 390 return 0; 391 else 392 return -EIO; 393 } 394 395 static int hpet_release(struct inode *inode, struct file *file) 396 { 397 struct hpet_dev *devp; 398 struct hpet_timer __iomem *timer; 399 int irq = 0; 400 401 devp = file->private_data; 402 timer = devp->hd_timer; 403 404 spin_lock_irq(&hpet_lock); 405 406 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 407 &timer->hpet_config); 408 409 irq = devp->hd_irq; 410 devp->hd_irq = 0; 411 412 devp->hd_ireqfreq = 0; 413 414 if (devp->hd_flags & HPET_PERIODIC 415 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 416 unsigned long v; 417 418 v = readq(&timer->hpet_config); 419 v ^= Tn_TYPE_CNF_MASK; 420 writeq(v, &timer->hpet_config); 421 } 422 423 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 424 spin_unlock_irq(&hpet_lock); 425 426 if (irq) 427 free_irq(irq, devp); 428 429 file->private_data = NULL; 430 return 0; 431 } 432 433 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 434 435 static int 436 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 437 unsigned long arg) 438 { 439 struct hpet_dev *devp; 440 441 devp = file->private_data; 442 return hpet_ioctl_common(devp, cmd, arg, 0); 443 } 444 445 static int hpet_ioctl_ieon(struct hpet_dev *devp) 446 { 447 struct hpet_timer __iomem *timer; 448 struct hpet __iomem *hpet; 449 struct hpets *hpetp; 450 int irq; 451 unsigned long g, v, t, m; 452 unsigned long flags, isr; 453 454 timer = devp->hd_timer; 455 hpet = devp->hd_hpet; 456 hpetp = devp->hd_hpets; 457 458 if (!devp->hd_ireqfreq) 459 return -EIO; 460 461 spin_lock_irq(&hpet_lock); 462 463 if (devp->hd_flags & HPET_IE) { 464 spin_unlock_irq(&hpet_lock); 465 return -EBUSY; 466 } 467 468 devp->hd_flags |= HPET_IE; 469 470 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 471 devp->hd_flags |= HPET_SHARED_IRQ; 472 spin_unlock_irq(&hpet_lock); 473 474 irq = devp->hd_hdwirq; 475 476 if (irq) { 477 unsigned long irq_flags; 478 479 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 480 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 481 ? IRQF_SHARED : IRQF_DISABLED; 482 if (request_irq(irq, hpet_interrupt, irq_flags, 483 devp->hd_name, (void *)devp)) { 484 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 485 irq = 0; 486 } 487 } 488 489 if (irq == 0) { 490 spin_lock_irq(&hpet_lock); 491 devp->hd_flags ^= HPET_IE; 492 spin_unlock_irq(&hpet_lock); 493 return -EIO; 494 } 495 496 devp->hd_irq = irq; 497 t = devp->hd_ireqfreq; 498 v = readq(&timer->hpet_config); 499 500 /* 64-bit comparators are not yet supported through the ioctls, 501 * so force this into 32-bit mode if it supports both modes 502 */ 503 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; 504 505 if (devp->hd_flags & HPET_PERIODIC) { 506 g |= Tn_TYPE_CNF_MASK; 507 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; 508 writeq(v, &timer->hpet_config); 509 local_irq_save(flags); 510 511 /* 512 * NOTE: First we modify the hidden accumulator 513 * register supported by periodic-capable comparators. 514 * We never want to modify the (single) counter; that 515 * would affect all the comparators. The value written 516 * is the counter value when the first interrupt is due. 517 */ 518 m = read_counter(&hpet->hpet_mc); 519 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 520 /* 521 * Then we modify the comparator, indicating the period 522 * for subsequent interrupt. 523 */ 524 write_counter(t, &timer->hpet_compare); 525 } else { 526 local_irq_save(flags); 527 m = read_counter(&hpet->hpet_mc); 528 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 529 } 530 531 if (devp->hd_flags & HPET_SHARED_IRQ) { 532 isr = 1 << (devp - devp->hd_hpets->hp_dev); 533 writel(isr, &hpet->hpet_isr); 534 } 535 writeq(g, &timer->hpet_config); 536 local_irq_restore(flags); 537 538 return 0; 539 } 540 541 /* converts Hz to number of timer ticks */ 542 static inline unsigned long hpet_time_div(struct hpets *hpets, 543 unsigned long dis) 544 { 545 unsigned long long m; 546 547 m = hpets->hp_tick_freq + (dis >> 1); 548 do_div(m, dis); 549 return (unsigned long)m; 550 } 551 552 static int 553 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 554 { 555 struct hpet_timer __iomem *timer; 556 struct hpet __iomem *hpet; 557 struct hpets *hpetp; 558 int err; 559 unsigned long v; 560 561 switch (cmd) { 562 case HPET_IE_OFF: 563 case HPET_INFO: 564 case HPET_EPI: 565 case HPET_DPI: 566 case HPET_IRQFREQ: 567 timer = devp->hd_timer; 568 hpet = devp->hd_hpet; 569 hpetp = devp->hd_hpets; 570 break; 571 case HPET_IE_ON: 572 return hpet_ioctl_ieon(devp); 573 default: 574 return -EINVAL; 575 } 576 577 err = 0; 578 579 switch (cmd) { 580 case HPET_IE_OFF: 581 if ((devp->hd_flags & HPET_IE) == 0) 582 break; 583 v = readq(&timer->hpet_config); 584 v &= ~Tn_INT_ENB_CNF_MASK; 585 writeq(v, &timer->hpet_config); 586 if (devp->hd_irq) { 587 free_irq(devp->hd_irq, devp); 588 devp->hd_irq = 0; 589 } 590 devp->hd_flags ^= HPET_IE; 591 break; 592 case HPET_INFO: 593 { 594 struct hpet_info info; 595 596 if (devp->hd_ireqfreq) 597 info.hi_ireqfreq = 598 hpet_time_div(hpetp, devp->hd_ireqfreq); 599 else 600 info.hi_ireqfreq = 0; 601 info.hi_flags = 602 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 603 info.hi_hpet = hpetp->hp_which; 604 info.hi_timer = devp - hpetp->hp_dev; 605 if (kernel) 606 memcpy((void *)arg, &info, sizeof(info)); 607 else 608 if (copy_to_user((void __user *)arg, &info, 609 sizeof(info))) 610 err = -EFAULT; 611 break; 612 } 613 case HPET_EPI: 614 v = readq(&timer->hpet_config); 615 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 616 err = -ENXIO; 617 break; 618 } 619 devp->hd_flags |= HPET_PERIODIC; 620 break; 621 case HPET_DPI: 622 v = readq(&timer->hpet_config); 623 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 624 err = -ENXIO; 625 break; 626 } 627 if (devp->hd_flags & HPET_PERIODIC && 628 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 629 v = readq(&timer->hpet_config); 630 v ^= Tn_TYPE_CNF_MASK; 631 writeq(v, &timer->hpet_config); 632 } 633 devp->hd_flags &= ~HPET_PERIODIC; 634 break; 635 case HPET_IRQFREQ: 636 if (!kernel && (arg > hpet_max_freq) && 637 !capable(CAP_SYS_RESOURCE)) { 638 err = -EACCES; 639 break; 640 } 641 642 if (!arg) { 643 err = -EINVAL; 644 break; 645 } 646 647 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 648 } 649 650 return err; 651 } 652 653 static const struct file_operations hpet_fops = { 654 .owner = THIS_MODULE, 655 .llseek = no_llseek, 656 .read = hpet_read, 657 .poll = hpet_poll, 658 .ioctl = hpet_ioctl, 659 .open = hpet_open, 660 .release = hpet_release, 661 .fasync = hpet_fasync, 662 .mmap = hpet_mmap, 663 }; 664 665 static int hpet_is_known(struct hpet_data *hdp) 666 { 667 struct hpets *hpetp; 668 669 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 670 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 671 return 1; 672 673 return 0; 674 } 675 676 static ctl_table hpet_table[] = { 677 { 678 .ctl_name = CTL_UNNUMBERED, 679 .procname = "max-user-freq", 680 .data = &hpet_max_freq, 681 .maxlen = sizeof(int), 682 .mode = 0644, 683 .proc_handler = &proc_dointvec, 684 }, 685 {.ctl_name = 0} 686 }; 687 688 static ctl_table hpet_root[] = { 689 { 690 .ctl_name = CTL_UNNUMBERED, 691 .procname = "hpet", 692 .maxlen = 0, 693 .mode = 0555, 694 .child = hpet_table, 695 }, 696 {.ctl_name = 0} 697 }; 698 699 static ctl_table dev_root[] = { 700 { 701 .ctl_name = CTL_DEV, 702 .procname = "dev", 703 .maxlen = 0, 704 .mode = 0555, 705 .child = hpet_root, 706 }, 707 {.ctl_name = 0} 708 }; 709 710 static struct ctl_table_header *sysctl_header; 711 712 /* 713 * Adjustment for when arming the timer with 714 * initial conditions. That is, main counter 715 * ticks expired before interrupts are enabled. 716 */ 717 #define TICK_CALIBRATE (1000UL) 718 719 static unsigned long __hpet_calibrate(struct hpets *hpetp) 720 { 721 struct hpet_timer __iomem *timer = NULL; 722 unsigned long t, m, count, i, flags, start; 723 struct hpet_dev *devp; 724 int j; 725 struct hpet __iomem *hpet; 726 727 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 728 if ((devp->hd_flags & HPET_OPEN) == 0) { 729 timer = devp->hd_timer; 730 break; 731 } 732 733 if (!timer) 734 return 0; 735 736 hpet = hpetp->hp_hpet; 737 t = read_counter(&timer->hpet_compare); 738 739 i = 0; 740 count = hpet_time_div(hpetp, TICK_CALIBRATE); 741 742 local_irq_save(flags); 743 744 start = read_counter(&hpet->hpet_mc); 745 746 do { 747 m = read_counter(&hpet->hpet_mc); 748 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 749 } while (i++, (m - start) < count); 750 751 local_irq_restore(flags); 752 753 return (m - start) / i; 754 } 755 756 static unsigned long hpet_calibrate(struct hpets *hpetp) 757 { 758 unsigned long ret = -1; 759 unsigned long tmp; 760 761 /* 762 * Try to calibrate until return value becomes stable small value. 763 * If SMI interruption occurs in calibration loop, the return value 764 * will be big. This avoids its impact. 765 */ 766 for ( ; ; ) { 767 tmp = __hpet_calibrate(hpetp); 768 if (ret <= tmp) 769 break; 770 ret = tmp; 771 } 772 773 return ret; 774 } 775 776 int hpet_alloc(struct hpet_data *hdp) 777 { 778 u64 cap, mcfg; 779 struct hpet_dev *devp; 780 u32 i, ntimer; 781 struct hpets *hpetp; 782 size_t siz; 783 struct hpet __iomem *hpet; 784 static struct hpets *last = NULL; 785 unsigned long period; 786 unsigned long long temp; 787 u32 remainder; 788 789 /* 790 * hpet_alloc can be called by platform dependent code. 791 * If platform dependent code has allocated the hpet that 792 * ACPI has also reported, then we catch it here. 793 */ 794 if (hpet_is_known(hdp)) { 795 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 796 __func__); 797 return 0; 798 } 799 800 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 801 sizeof(struct hpet_dev)); 802 803 hpetp = kzalloc(siz, GFP_KERNEL); 804 805 if (!hpetp) 806 return -ENOMEM; 807 808 hpetp->hp_which = hpet_nhpet++; 809 hpetp->hp_hpet = hdp->hd_address; 810 hpetp->hp_hpet_phys = hdp->hd_phys_address; 811 812 hpetp->hp_ntimer = hdp->hd_nirqs; 813 814 for (i = 0; i < hdp->hd_nirqs; i++) 815 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 816 817 hpet = hpetp->hp_hpet; 818 819 cap = readq(&hpet->hpet_cap); 820 821 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 822 823 if (hpetp->hp_ntimer != ntimer) { 824 printk(KERN_WARNING "hpet: number irqs doesn't agree" 825 " with number of timers\n"); 826 kfree(hpetp); 827 return -ENODEV; 828 } 829 830 if (last) 831 last->hp_next = hpetp; 832 else 833 hpets = hpetp; 834 835 last = hpetp; 836 837 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 838 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 839 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 840 temp += period >> 1; /* round */ 841 do_div(temp, period); 842 hpetp->hp_tick_freq = temp; /* ticks per second */ 843 844 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 845 hpetp->hp_which, hdp->hd_phys_address, 846 hpetp->hp_ntimer > 1 ? "s" : ""); 847 for (i = 0; i < hpetp->hp_ntimer; i++) 848 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 849 printk("\n"); 850 851 temp = hpetp->hp_tick_freq; 852 remainder = do_div(temp, 1000000); 853 printk(KERN_INFO 854 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", 855 hpetp->hp_which, hpetp->hp_ntimer, 856 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, 857 (unsigned) temp, remainder); 858 859 mcfg = readq(&hpet->hpet_config); 860 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 861 write_counter(0L, &hpet->hpet_mc); 862 mcfg |= HPET_ENABLE_CNF_MASK; 863 writeq(mcfg, &hpet->hpet_config); 864 } 865 866 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 867 struct hpet_timer __iomem *timer; 868 869 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 870 871 devp->hd_hpets = hpetp; 872 devp->hd_hpet = hpet; 873 devp->hd_timer = timer; 874 875 /* 876 * If the timer was reserved by platform code, 877 * then make timer unavailable for opens. 878 */ 879 if (hdp->hd_state & (1 << i)) { 880 devp->hd_flags = HPET_OPEN; 881 continue; 882 } 883 884 init_waitqueue_head(&devp->hd_waitqueue); 885 } 886 887 hpetp->hp_delta = hpet_calibrate(hpetp); 888 889 /* This clocksource driver currently only works on ia64 */ 890 #ifdef CONFIG_IA64 891 if (!hpet_clocksource) { 892 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 893 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); 894 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, 895 clocksource_hpet.shift); 896 clocksource_register(&clocksource_hpet); 897 hpetp->hp_clocksource = &clocksource_hpet; 898 hpet_clocksource = &clocksource_hpet; 899 } 900 #endif 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; 910 911 hdp = data; 912 913 status = acpi_resource_to_address64(res, &addr); 914 915 if (ACPI_SUCCESS(status)) { 916 hdp->hd_phys_address = addr.minimum; 917 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 918 919 if (hpet_is_known(hdp)) { 920 iounmap(hdp->hd_address); 921 return AE_ALREADY_EXISTS; 922 } 923 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 924 struct acpi_resource_fixed_memory32 *fixmem32; 925 926 fixmem32 = &res->data.fixed_memory32; 927 if (!fixmem32) 928 return AE_NO_MEMORY; 929 930 hdp->hd_phys_address = fixmem32->address; 931 hdp->hd_address = ioremap(fixmem32->address, 932 HPET_RANGE_SIZE); 933 934 if (hpet_is_known(hdp)) { 935 iounmap(hdp->hd_address); 936 return AE_ALREADY_EXISTS; 937 } 938 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 939 struct acpi_resource_extended_irq *irqp; 940 int i, irq; 941 942 irqp = &res->data.extended_irq; 943 944 for (i = 0; i < irqp->interrupt_count; i++) { 945 irq = acpi_register_gsi(NULL, irqp->interrupts[i], 946 irqp->triggering, irqp->polarity); 947 if (irq < 0) 948 return AE_ERROR; 949 950 hdp->hd_irq[hdp->hd_nirqs] = irq; 951 hdp->hd_nirqs++; 952 } 953 } 954 955 return AE_OK; 956 } 957 958 static int hpet_acpi_add(struct acpi_device *device) 959 { 960 acpi_status result; 961 struct hpet_data data; 962 963 memset(&data, 0, sizeof(data)); 964 965 result = 966 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 967 hpet_resources, &data); 968 969 if (ACPI_FAILURE(result)) 970 return -ENODEV; 971 972 if (!data.hd_address || !data.hd_nirqs) { 973 printk("%s: no address or irqs in _CRS\n", __func__); 974 return -ENODEV; 975 } 976 977 return hpet_alloc(&data); 978 } 979 980 static int hpet_acpi_remove(struct acpi_device *device, int type) 981 { 982 /* XXX need to unregister clocksource, dealloc mem, etc */ 983 return -EINVAL; 984 } 985 986 static const struct acpi_device_id hpet_device_ids[] = { 987 {"PNP0103", 0}, 988 {"", 0}, 989 }; 990 MODULE_DEVICE_TABLE(acpi, hpet_device_ids); 991 992 static struct acpi_driver hpet_acpi_driver = { 993 .name = "hpet", 994 .ids = hpet_device_ids, 995 .ops = { 996 .add = hpet_acpi_add, 997 .remove = hpet_acpi_remove, 998 }, 999 }; 1000 1001 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1002 1003 static int __init hpet_init(void) 1004 { 1005 int result; 1006 1007 result = misc_register(&hpet_misc); 1008 if (result < 0) 1009 return -ENODEV; 1010 1011 sysctl_header = register_sysctl_table(dev_root); 1012 1013 result = acpi_bus_register_driver(&hpet_acpi_driver); 1014 if (result < 0) { 1015 if (sysctl_header) 1016 unregister_sysctl_table(sysctl_header); 1017 misc_deregister(&hpet_misc); 1018 return result; 1019 } 1020 1021 return 0; 1022 } 1023 1024 static void __exit hpet_exit(void) 1025 { 1026 acpi_bus_unregister_driver(&hpet_acpi_driver); 1027 1028 if (sysctl_header) 1029 unregister_sysctl_table(sysctl_header); 1030 misc_deregister(&hpet_misc); 1031 1032 return; 1033 } 1034 1035 module_init(hpet_init); 1036 module_exit(hpet_exit); 1037 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1038 MODULE_LICENSE("GPL"); 1039