1 /* 2 * Intel & MS High Precision Event Timer Implementation. 3 * 4 * Copyright (C) 2003 Intel Corporation 5 * Venki Pallipadi 6 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. 7 * Bob Picco <robert.picco@hp.com> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/interrupt.h> 15 #include <linux/module.h> 16 #include <linux/kernel.h> 17 #include <linux/smp_lock.h> 18 #include <linux/types.h> 19 #include <linux/miscdevice.h> 20 #include <linux/major.h> 21 #include <linux/ioport.h> 22 #include <linux/fcntl.h> 23 #include <linux/init.h> 24 #include <linux/poll.h> 25 #include <linux/mm.h> 26 #include <linux/proc_fs.h> 27 #include <linux/spinlock.h> 28 #include <linux/sysctl.h> 29 #include <linux/wait.h> 30 #include <linux/bcd.h> 31 #include <linux/seq_file.h> 32 #include <linux/bitops.h> 33 #include <linux/clocksource.h> 34 #include <linux/slab.h> 35 36 #include <asm/current.h> 37 #include <asm/uaccess.h> 38 #include <asm/system.h> 39 #include <asm/io.h> 40 #include <asm/irq.h> 41 #include <asm/div64.h> 42 43 #include <linux/acpi.h> 44 #include <acpi/acpi_bus.h> 45 #include <linux/hpet.h> 46 47 /* 48 * The High Precision Event Timer driver. 49 * This driver is closely modelled after the rtc.c driver. 50 * http://www.intel.com/hardwaredesign/hpetspec_1.pdf 51 */ 52 #define HPET_USER_FREQ (64) 53 #define HPET_DRIFT (500) 54 55 #define HPET_RANGE_SIZE 1024 /* from HPET spec */ 56 57 58 /* WARNING -- don't get confused. These macros are never used 59 * to write the (single) counter, and rarely to read it. 60 * They're badly named; to fix, someday. 61 */ 62 #if BITS_PER_LONG == 64 63 #define write_counter(V, MC) writeq(V, MC) 64 #define read_counter(MC) readq(MC) 65 #else 66 #define write_counter(V, MC) writel(V, MC) 67 #define read_counter(MC) readl(MC) 68 #endif 69 70 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 71 72 /* This clocksource driver currently only works on ia64 */ 73 #ifdef CONFIG_IA64 74 static void __iomem *hpet_mctr; 75 76 static cycle_t read_hpet(struct clocksource *cs) 77 { 78 return (cycle_t)read_counter((void __iomem *)hpet_mctr); 79 } 80 81 static struct clocksource clocksource_hpet = { 82 .name = "hpet", 83 .rating = 250, 84 .read = read_hpet, 85 .mask = CLOCKSOURCE_MASK(64), 86 .mult = 0, /* to be calculated */ 87 .shift = 10, 88 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 89 }; 90 static struct clocksource *hpet_clocksource; 91 #endif 92 93 /* A lock for concurrent access by app and isr hpet activity. */ 94 static DEFINE_SPINLOCK(hpet_lock); 95 96 #define HPET_DEV_NAME (7) 97 98 struct hpet_dev { 99 struct hpets *hd_hpets; 100 struct hpet __iomem *hd_hpet; 101 struct hpet_timer __iomem *hd_timer; 102 unsigned long hd_ireqfreq; 103 unsigned long hd_irqdata; 104 wait_queue_head_t hd_waitqueue; 105 struct fasync_struct *hd_async_queue; 106 unsigned int hd_flags; 107 unsigned int hd_irq; 108 unsigned int hd_hdwirq; 109 char hd_name[HPET_DEV_NAME]; 110 }; 111 112 struct hpets { 113 struct hpets *hp_next; 114 struct hpet __iomem *hp_hpet; 115 unsigned long hp_hpet_phys; 116 struct clocksource *hp_clocksource; 117 unsigned long long hp_tick_freq; 118 unsigned long hp_delta; 119 unsigned int hp_ntimer; 120 unsigned int hp_which; 121 struct hpet_dev hp_dev[1]; 122 }; 123 124 static struct hpets *hpets; 125 126 #define HPET_OPEN 0x0001 127 #define HPET_IE 0x0002 /* interrupt enabled */ 128 #define HPET_PERIODIC 0x0004 129 #define HPET_SHARED_IRQ 0x0008 130 131 132 #ifndef readq 133 static inline unsigned long long readq(void __iomem *addr) 134 { 135 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 136 } 137 #endif 138 139 #ifndef writeq 140 static inline void writeq(unsigned long long v, void __iomem *addr) 141 { 142 writel(v & 0xffffffff, addr); 143 writel(v >> 32, addr + 4); 144 } 145 #endif 146 147 static irqreturn_t hpet_interrupt(int irq, void *data) 148 { 149 struct hpet_dev *devp; 150 unsigned long isr; 151 152 devp = data; 153 isr = 1 << (devp - devp->hd_hpets->hp_dev); 154 155 if ((devp->hd_flags & HPET_SHARED_IRQ) && 156 !(isr & readl(&devp->hd_hpet->hpet_isr))) 157 return IRQ_NONE; 158 159 spin_lock(&hpet_lock); 160 devp->hd_irqdata++; 161 162 /* 163 * For non-periodic timers, increment the accumulator. 164 * This has the effect of treating non-periodic like periodic. 165 */ 166 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 167 unsigned long m, t; 168 169 t = devp->hd_ireqfreq; 170 m = read_counter(&devp->hd_timer->hpet_compare); 171 write_counter(t + m, &devp->hd_timer->hpet_compare); 172 } 173 174 if (devp->hd_flags & HPET_SHARED_IRQ) 175 writel(isr, &devp->hd_hpet->hpet_isr); 176 spin_unlock(&hpet_lock); 177 178 wake_up_interruptible(&devp->hd_waitqueue); 179 180 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 181 182 return IRQ_HANDLED; 183 } 184 185 static void hpet_timer_set_irq(struct hpet_dev *devp) 186 { 187 unsigned long v; 188 int irq, gsi; 189 struct hpet_timer __iomem *timer; 190 191 spin_lock_irq(&hpet_lock); 192 if (devp->hd_hdwirq) { 193 spin_unlock_irq(&hpet_lock); 194 return; 195 } 196 197 timer = devp->hd_timer; 198 199 /* we prefer level triggered mode */ 200 v = readl(&timer->hpet_config); 201 if (!(v & Tn_INT_TYPE_CNF_MASK)) { 202 v |= Tn_INT_TYPE_CNF_MASK; 203 writel(v, &timer->hpet_config); 204 } 205 spin_unlock_irq(&hpet_lock); 206 207 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> 208 Tn_INT_ROUTE_CAP_SHIFT; 209 210 /* 211 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by 212 * legacy device. In IO APIC mode, we skip all the legacy IRQS. 213 */ 214 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) 215 v &= ~0xf3df; 216 else 217 v &= ~0xffff; 218 219 for_each_set_bit(irq, &v, HPET_MAX_IRQ) { 220 if (irq >= nr_irqs) { 221 irq = HPET_MAX_IRQ; 222 break; 223 } 224 225 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, 226 ACPI_ACTIVE_LOW); 227 if (gsi > 0) 228 break; 229 230 /* FIXME: Setup interrupt source table */ 231 } 232 233 if (irq < HPET_MAX_IRQ) { 234 spin_lock_irq(&hpet_lock); 235 v = readl(&timer->hpet_config); 236 v |= irq << Tn_INT_ROUTE_CNF_SHIFT; 237 writel(v, &timer->hpet_config); 238 devp->hd_hdwirq = gsi; 239 spin_unlock_irq(&hpet_lock); 240 } 241 return; 242 } 243 244 static int hpet_open(struct inode *inode, struct file *file) 245 { 246 struct hpet_dev *devp; 247 struct hpets *hpetp; 248 int i; 249 250 if (file->f_mode & FMODE_WRITE) 251 return -EINVAL; 252 253 lock_kernel(); 254 spin_lock_irq(&hpet_lock); 255 256 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 257 for (i = 0; i < hpetp->hp_ntimer; i++) 258 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) 259 continue; 260 else { 261 devp = &hpetp->hp_dev[i]; 262 break; 263 } 264 265 if (!devp) { 266 spin_unlock_irq(&hpet_lock); 267 unlock_kernel(); 268 return -EBUSY; 269 } 270 271 file->private_data = devp; 272 devp->hd_irqdata = 0; 273 devp->hd_flags |= HPET_OPEN; 274 spin_unlock_irq(&hpet_lock); 275 unlock_kernel(); 276 277 hpet_timer_set_irq(devp); 278 279 return 0; 280 } 281 282 static ssize_t 283 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 284 { 285 DECLARE_WAITQUEUE(wait, current); 286 unsigned long data; 287 ssize_t retval; 288 struct hpet_dev *devp; 289 290 devp = file->private_data; 291 if (!devp->hd_ireqfreq) 292 return -EIO; 293 294 if (count < sizeof(unsigned long)) 295 return -EINVAL; 296 297 add_wait_queue(&devp->hd_waitqueue, &wait); 298 299 for ( ; ; ) { 300 set_current_state(TASK_INTERRUPTIBLE); 301 302 spin_lock_irq(&hpet_lock); 303 data = devp->hd_irqdata; 304 devp->hd_irqdata = 0; 305 spin_unlock_irq(&hpet_lock); 306 307 if (data) 308 break; 309 else if (file->f_flags & O_NONBLOCK) { 310 retval = -EAGAIN; 311 goto out; 312 } else if (signal_pending(current)) { 313 retval = -ERESTARTSYS; 314 goto out; 315 } 316 schedule(); 317 } 318 319 retval = put_user(data, (unsigned long __user *)buf); 320 if (!retval) 321 retval = sizeof(unsigned long); 322 out: 323 __set_current_state(TASK_RUNNING); 324 remove_wait_queue(&devp->hd_waitqueue, &wait); 325 326 return retval; 327 } 328 329 static unsigned int hpet_poll(struct file *file, poll_table * wait) 330 { 331 unsigned long v; 332 struct hpet_dev *devp; 333 334 devp = file->private_data; 335 336 if (!devp->hd_ireqfreq) 337 return 0; 338 339 poll_wait(file, &devp->hd_waitqueue, wait); 340 341 spin_lock_irq(&hpet_lock); 342 v = devp->hd_irqdata; 343 spin_unlock_irq(&hpet_lock); 344 345 if (v != 0) 346 return POLLIN | POLLRDNORM; 347 348 return 0; 349 } 350 351 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 352 { 353 #ifdef CONFIG_HPET_MMAP 354 struct hpet_dev *devp; 355 unsigned long addr; 356 357 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 358 return -EINVAL; 359 360 devp = file->private_data; 361 addr = devp->hd_hpets->hp_hpet_phys; 362 363 if (addr & (PAGE_SIZE - 1)) 364 return -ENOSYS; 365 366 vma->vm_flags |= VM_IO; 367 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 368 369 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 370 PAGE_SIZE, vma->vm_page_prot)) { 371 printk(KERN_ERR "%s: io_remap_pfn_range failed\n", 372 __func__); 373 return -EAGAIN; 374 } 375 376 return 0; 377 #else 378 return -ENOSYS; 379 #endif 380 } 381 382 static int hpet_fasync(int fd, struct file *file, int on) 383 { 384 struct hpet_dev *devp; 385 386 devp = file->private_data; 387 388 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 389 return 0; 390 else 391 return -EIO; 392 } 393 394 static int hpet_release(struct inode *inode, struct file *file) 395 { 396 struct hpet_dev *devp; 397 struct hpet_timer __iomem *timer; 398 int irq = 0; 399 400 devp = file->private_data; 401 timer = devp->hd_timer; 402 403 spin_lock_irq(&hpet_lock); 404 405 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 406 &timer->hpet_config); 407 408 irq = devp->hd_irq; 409 devp->hd_irq = 0; 410 411 devp->hd_ireqfreq = 0; 412 413 if (devp->hd_flags & HPET_PERIODIC 414 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 415 unsigned long v; 416 417 v = readq(&timer->hpet_config); 418 v ^= Tn_TYPE_CNF_MASK; 419 writeq(v, &timer->hpet_config); 420 } 421 422 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 423 spin_unlock_irq(&hpet_lock); 424 425 if (irq) 426 free_irq(irq, devp); 427 428 file->private_data = NULL; 429 return 0; 430 } 431 432 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 433 434 static long hpet_ioctl(struct file *file, unsigned int cmd, 435 unsigned long arg) 436 { 437 struct hpet_dev *devp; 438 int ret; 439 440 devp = file->private_data; 441 lock_kernel(); 442 ret = hpet_ioctl_common(devp, cmd, arg, 0); 443 unlock_kernel(); 444 445 return ret; 446 } 447 448 static int hpet_ioctl_ieon(struct hpet_dev *devp) 449 { 450 struct hpet_timer __iomem *timer; 451 struct hpet __iomem *hpet; 452 struct hpets *hpetp; 453 int irq; 454 unsigned long g, v, t, m; 455 unsigned long flags, isr; 456 457 timer = devp->hd_timer; 458 hpet = devp->hd_hpet; 459 hpetp = devp->hd_hpets; 460 461 if (!devp->hd_ireqfreq) 462 return -EIO; 463 464 spin_lock_irq(&hpet_lock); 465 466 if (devp->hd_flags & HPET_IE) { 467 spin_unlock_irq(&hpet_lock); 468 return -EBUSY; 469 } 470 471 devp->hd_flags |= HPET_IE; 472 473 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 474 devp->hd_flags |= HPET_SHARED_IRQ; 475 spin_unlock_irq(&hpet_lock); 476 477 irq = devp->hd_hdwirq; 478 479 if (irq) { 480 unsigned long irq_flags; 481 482 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 483 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 484 ? IRQF_SHARED : IRQF_DISABLED; 485 if (request_irq(irq, hpet_interrupt, irq_flags, 486 devp->hd_name, (void *)devp)) { 487 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 488 irq = 0; 489 } 490 } 491 492 if (irq == 0) { 493 spin_lock_irq(&hpet_lock); 494 devp->hd_flags ^= HPET_IE; 495 spin_unlock_irq(&hpet_lock); 496 return -EIO; 497 } 498 499 devp->hd_irq = irq; 500 t = devp->hd_ireqfreq; 501 v = readq(&timer->hpet_config); 502 503 /* 64-bit comparators are not yet supported through the ioctls, 504 * so force this into 32-bit mode if it supports both modes 505 */ 506 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; 507 508 if (devp->hd_flags & HPET_PERIODIC) { 509 g |= Tn_TYPE_CNF_MASK; 510 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; 511 writeq(v, &timer->hpet_config); 512 local_irq_save(flags); 513 514 /* 515 * NOTE: First we modify the hidden accumulator 516 * register supported by periodic-capable comparators. 517 * We never want to modify the (single) counter; that 518 * would affect all the comparators. The value written 519 * is the counter value when the first interrupt is due. 520 */ 521 m = read_counter(&hpet->hpet_mc); 522 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 523 /* 524 * Then we modify the comparator, indicating the period 525 * for subsequent interrupt. 526 */ 527 write_counter(t, &timer->hpet_compare); 528 } else { 529 local_irq_save(flags); 530 m = read_counter(&hpet->hpet_mc); 531 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 532 } 533 534 if (devp->hd_flags & HPET_SHARED_IRQ) { 535 isr = 1 << (devp - devp->hd_hpets->hp_dev); 536 writel(isr, &hpet->hpet_isr); 537 } 538 writeq(g, &timer->hpet_config); 539 local_irq_restore(flags); 540 541 return 0; 542 } 543 544 /* converts Hz to number of timer ticks */ 545 static inline unsigned long hpet_time_div(struct hpets *hpets, 546 unsigned long dis) 547 { 548 unsigned long long m; 549 550 m = hpets->hp_tick_freq + (dis >> 1); 551 do_div(m, dis); 552 return (unsigned long)m; 553 } 554 555 static int 556 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 557 { 558 struct hpet_timer __iomem *timer; 559 struct hpet __iomem *hpet; 560 struct hpets *hpetp; 561 int err; 562 unsigned long v; 563 564 switch (cmd) { 565 case HPET_IE_OFF: 566 case HPET_INFO: 567 case HPET_EPI: 568 case HPET_DPI: 569 case HPET_IRQFREQ: 570 timer = devp->hd_timer; 571 hpet = devp->hd_hpet; 572 hpetp = devp->hd_hpets; 573 break; 574 case HPET_IE_ON: 575 return hpet_ioctl_ieon(devp); 576 default: 577 return -EINVAL; 578 } 579 580 err = 0; 581 582 switch (cmd) { 583 case HPET_IE_OFF: 584 if ((devp->hd_flags & HPET_IE) == 0) 585 break; 586 v = readq(&timer->hpet_config); 587 v &= ~Tn_INT_ENB_CNF_MASK; 588 writeq(v, &timer->hpet_config); 589 if (devp->hd_irq) { 590 free_irq(devp->hd_irq, devp); 591 devp->hd_irq = 0; 592 } 593 devp->hd_flags ^= HPET_IE; 594 break; 595 case HPET_INFO: 596 { 597 struct hpet_info info; 598 599 if (devp->hd_ireqfreq) 600 info.hi_ireqfreq = 601 hpet_time_div(hpetp, devp->hd_ireqfreq); 602 else 603 info.hi_ireqfreq = 0; 604 info.hi_flags = 605 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 606 info.hi_hpet = hpetp->hp_which; 607 info.hi_timer = devp - hpetp->hp_dev; 608 if (kernel) 609 memcpy((void *)arg, &info, sizeof(info)); 610 else 611 if (copy_to_user((void __user *)arg, &info, 612 sizeof(info))) 613 err = -EFAULT; 614 break; 615 } 616 case HPET_EPI: 617 v = readq(&timer->hpet_config); 618 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 619 err = -ENXIO; 620 break; 621 } 622 devp->hd_flags |= HPET_PERIODIC; 623 break; 624 case HPET_DPI: 625 v = readq(&timer->hpet_config); 626 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 627 err = -ENXIO; 628 break; 629 } 630 if (devp->hd_flags & HPET_PERIODIC && 631 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 632 v = readq(&timer->hpet_config); 633 v ^= Tn_TYPE_CNF_MASK; 634 writeq(v, &timer->hpet_config); 635 } 636 devp->hd_flags &= ~HPET_PERIODIC; 637 break; 638 case HPET_IRQFREQ: 639 if (!kernel && (arg > hpet_max_freq) && 640 !capable(CAP_SYS_RESOURCE)) { 641 err = -EACCES; 642 break; 643 } 644 645 if (!arg) { 646 err = -EINVAL; 647 break; 648 } 649 650 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 651 } 652 653 return err; 654 } 655 656 static const struct file_operations hpet_fops = { 657 .owner = THIS_MODULE, 658 .llseek = no_llseek, 659 .read = hpet_read, 660 .poll = hpet_poll, 661 .unlocked_ioctl = hpet_ioctl, 662 .open = hpet_open, 663 .release = hpet_release, 664 .fasync = hpet_fasync, 665 .mmap = hpet_mmap, 666 }; 667 668 static int hpet_is_known(struct hpet_data *hdp) 669 { 670 struct hpets *hpetp; 671 672 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 673 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 674 return 1; 675 676 return 0; 677 } 678 679 static ctl_table hpet_table[] = { 680 { 681 .procname = "max-user-freq", 682 .data = &hpet_max_freq, 683 .maxlen = sizeof(int), 684 .mode = 0644, 685 .proc_handler = proc_dointvec, 686 }, 687 {} 688 }; 689 690 static ctl_table hpet_root[] = { 691 { 692 .procname = "hpet", 693 .maxlen = 0, 694 .mode = 0555, 695 .child = hpet_table, 696 }, 697 {} 698 }; 699 700 static ctl_table dev_root[] = { 701 { 702 .procname = "dev", 703 .maxlen = 0, 704 .mode = 0555, 705 .child = hpet_root, 706 }, 707 {} 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