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/mm.h> 25 #include <linux/proc_fs.h> 26 #include <linux/spinlock.h> 27 #include <linux/sysctl.h> 28 #include <linux/wait.h> 29 #include <linux/bcd.h> 30 #include <linux/seq_file.h> 31 #include <linux/bitops.h> 32 #include <linux/compat.h> 33 #include <linux/clocksource.h> 34 #include <linux/uaccess.h> 35 #include <linux/slab.h> 36 #include <linux/io.h> 37 38 #include <asm/current.h> 39 #include <asm/system.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 DEFINE_MUTEX(hpet_mutex); /* replaces BKL */ 71 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 72 73 /* This clocksource driver currently only works on ia64 */ 74 #ifdef CONFIG_IA64 75 static void __iomem *hpet_mctr; 76 77 static cycle_t read_hpet(struct clocksource *cs) 78 { 79 return (cycle_t)read_counter((void __iomem *)hpet_mctr); 80 } 81 82 static struct clocksource clocksource_hpet = { 83 .name = "hpet", 84 .rating = 250, 85 .read = read_hpet, 86 .mask = CLOCKSOURCE_MASK(64), 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_each_set_bit(irq, &v, HPET_MAX_IRQ) { 219 if (irq >= nr_irqs) { 220 irq = HPET_MAX_IRQ; 221 break; 222 } 223 224 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, 225 ACPI_ACTIVE_LOW); 226 if (gsi > 0) 227 break; 228 229 /* FIXME: Setup interrupt source table */ 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 } 242 243 static 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 mutex_lock(&hpet_mutex); 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 mutex_unlock(&hpet_mutex); 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 mutex_unlock(&hpet_mutex); 275 276 hpet_timer_set_irq(devp); 277 278 return 0; 279 } 280 281 static ssize_t 282 hpet_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); 321 out: 322 __set_current_state(TASK_RUNNING); 323 remove_wait_queue(&devp->hd_waitqueue, &wait); 324 325 return retval; 326 } 327 328 static 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 } 349 350 static 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 } 380 381 static 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 } 392 393 static 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 } 430 431 static int hpet_ioctl_ieon(struct hpet_dev *devp) 432 { 433 struct hpet_timer __iomem *timer; 434 struct hpet __iomem *hpet; 435 struct hpets *hpetp; 436 int irq; 437 unsigned long g, v, t, m; 438 unsigned long flags, isr; 439 440 timer = devp->hd_timer; 441 hpet = devp->hd_hpet; 442 hpetp = devp->hd_hpets; 443 444 if (!devp->hd_ireqfreq) 445 return -EIO; 446 447 spin_lock_irq(&hpet_lock); 448 449 if (devp->hd_flags & HPET_IE) { 450 spin_unlock_irq(&hpet_lock); 451 return -EBUSY; 452 } 453 454 devp->hd_flags |= HPET_IE; 455 456 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 457 devp->hd_flags |= HPET_SHARED_IRQ; 458 spin_unlock_irq(&hpet_lock); 459 460 irq = devp->hd_hdwirq; 461 462 if (irq) { 463 unsigned long irq_flags; 464 465 if (devp->hd_flags & HPET_SHARED_IRQ) { 466 /* 467 * To prevent the interrupt handler from seeing an 468 * unwanted interrupt status bit, program the timer 469 * so that it will not fire in the near future ... 470 */ 471 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, 472 &timer->hpet_config); 473 write_counter(read_counter(&hpet->hpet_mc), 474 &timer->hpet_compare); 475 /* ... and clear any left-over status. */ 476 isr = 1 << (devp - devp->hd_hpets->hp_dev); 477 writel(isr, &hpet->hpet_isr); 478 } 479 480 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 481 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 482 ? IRQF_SHARED : IRQF_DISABLED; 483 if (request_irq(irq, hpet_interrupt, irq_flags, 484 devp->hd_name, (void *)devp)) { 485 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 486 irq = 0; 487 } 488 } 489 490 if (irq == 0) { 491 spin_lock_irq(&hpet_lock); 492 devp->hd_flags ^= HPET_IE; 493 spin_unlock_irq(&hpet_lock); 494 return -EIO; 495 } 496 497 devp->hd_irq = irq; 498 t = devp->hd_ireqfreq; 499 v = readq(&timer->hpet_config); 500 501 /* 64-bit comparators are not yet supported through the ioctls, 502 * so force this into 32-bit mode if it supports both modes 503 */ 504 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; 505 506 if (devp->hd_flags & HPET_PERIODIC) { 507 g |= Tn_TYPE_CNF_MASK; 508 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; 509 writeq(v, &timer->hpet_config); 510 local_irq_save(flags); 511 512 /* 513 * NOTE: First we modify the hidden accumulator 514 * register supported by periodic-capable comparators. 515 * We never want to modify the (single) counter; that 516 * would affect all the comparators. The value written 517 * is the counter value when the first interrupt is due. 518 */ 519 m = read_counter(&hpet->hpet_mc); 520 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 521 /* 522 * Then we modify the comparator, indicating the period 523 * for subsequent interrupt. 524 */ 525 write_counter(t, &timer->hpet_compare); 526 } else { 527 local_irq_save(flags); 528 m = read_counter(&hpet->hpet_mc); 529 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 530 } 531 532 if (devp->hd_flags & HPET_SHARED_IRQ) { 533 isr = 1 << (devp - devp->hd_hpets->hp_dev); 534 writel(isr, &hpet->hpet_isr); 535 } 536 writeq(g, &timer->hpet_config); 537 local_irq_restore(flags); 538 539 return 0; 540 } 541 542 /* converts Hz to number of timer ticks */ 543 static inline unsigned long hpet_time_div(struct hpets *hpets, 544 unsigned long dis) 545 { 546 unsigned long long m; 547 548 m = hpets->hp_tick_freq + (dis >> 1); 549 do_div(m, dis); 550 return (unsigned long)m; 551 } 552 553 static int 554 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, 555 struct hpet_info *info) 556 { 557 struct hpet_timer __iomem *timer; 558 struct hpet __iomem *hpet; 559 struct hpets *hpetp; 560 int err; 561 unsigned long v; 562 563 switch (cmd) { 564 case HPET_IE_OFF: 565 case HPET_INFO: 566 case HPET_EPI: 567 case HPET_DPI: 568 case HPET_IRQFREQ: 569 timer = devp->hd_timer; 570 hpet = devp->hd_hpet; 571 hpetp = devp->hd_hpets; 572 break; 573 case HPET_IE_ON: 574 return hpet_ioctl_ieon(devp); 575 default: 576 return -EINVAL; 577 } 578 579 err = 0; 580 581 switch (cmd) { 582 case HPET_IE_OFF: 583 if ((devp->hd_flags & HPET_IE) == 0) 584 break; 585 v = readq(&timer->hpet_config); 586 v &= ~Tn_INT_ENB_CNF_MASK; 587 writeq(v, &timer->hpet_config); 588 if (devp->hd_irq) { 589 free_irq(devp->hd_irq, devp); 590 devp->hd_irq = 0; 591 } 592 devp->hd_flags ^= HPET_IE; 593 break; 594 case HPET_INFO: 595 { 596 memset(info, 0, sizeof(*info)); 597 if (devp->hd_ireqfreq) 598 info->hi_ireqfreq = 599 hpet_time_div(hpetp, devp->hd_ireqfreq); 600 info->hi_flags = 601 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 602 info->hi_hpet = hpetp->hp_which; 603 info->hi_timer = devp - hpetp->hp_dev; 604 break; 605 } 606 case HPET_EPI: 607 v = readq(&timer->hpet_config); 608 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 609 err = -ENXIO; 610 break; 611 } 612 devp->hd_flags |= HPET_PERIODIC; 613 break; 614 case HPET_DPI: 615 v = readq(&timer->hpet_config); 616 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 617 err = -ENXIO; 618 break; 619 } 620 if (devp->hd_flags & HPET_PERIODIC && 621 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 622 v = readq(&timer->hpet_config); 623 v ^= Tn_TYPE_CNF_MASK; 624 writeq(v, &timer->hpet_config); 625 } 626 devp->hd_flags &= ~HPET_PERIODIC; 627 break; 628 case HPET_IRQFREQ: 629 if ((arg > hpet_max_freq) && 630 !capable(CAP_SYS_RESOURCE)) { 631 err = -EACCES; 632 break; 633 } 634 635 if (!arg) { 636 err = -EINVAL; 637 break; 638 } 639 640 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 641 } 642 643 return err; 644 } 645 646 static long 647 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 648 { 649 struct hpet_info info; 650 int err; 651 652 mutex_lock(&hpet_mutex); 653 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 654 mutex_unlock(&hpet_mutex); 655 656 if ((cmd == HPET_INFO) && !err && 657 (copy_to_user((void __user *)arg, &info, sizeof(info)))) 658 err = -EFAULT; 659 660 return err; 661 } 662 663 #ifdef CONFIG_COMPAT 664 struct compat_hpet_info { 665 compat_ulong_t hi_ireqfreq; /* Hz */ 666 compat_ulong_t hi_flags; /* information */ 667 unsigned short hi_hpet; 668 unsigned short hi_timer; 669 }; 670 671 static long 672 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 673 { 674 struct hpet_info info; 675 int err; 676 677 mutex_lock(&hpet_mutex); 678 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 679 mutex_unlock(&hpet_mutex); 680 681 if ((cmd == HPET_INFO) && !err) { 682 struct compat_hpet_info __user *u = compat_ptr(arg); 683 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) || 684 put_user(info.hi_flags, &u->hi_flags) || 685 put_user(info.hi_hpet, &u->hi_hpet) || 686 put_user(info.hi_timer, &u->hi_timer)) 687 err = -EFAULT; 688 } 689 690 return err; 691 } 692 #endif 693 694 static const struct file_operations hpet_fops = { 695 .owner = THIS_MODULE, 696 .llseek = no_llseek, 697 .read = hpet_read, 698 .poll = hpet_poll, 699 .unlocked_ioctl = hpet_ioctl, 700 #ifdef CONFIG_COMPAT 701 .compat_ioctl = hpet_compat_ioctl, 702 #endif 703 .open = hpet_open, 704 .release = hpet_release, 705 .fasync = hpet_fasync, 706 .mmap = hpet_mmap, 707 }; 708 709 static int hpet_is_known(struct hpet_data *hdp) 710 { 711 struct hpets *hpetp; 712 713 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 714 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 715 return 1; 716 717 return 0; 718 } 719 720 static ctl_table hpet_table[] = { 721 { 722 .procname = "max-user-freq", 723 .data = &hpet_max_freq, 724 .maxlen = sizeof(int), 725 .mode = 0644, 726 .proc_handler = proc_dointvec, 727 }, 728 {} 729 }; 730 731 static ctl_table hpet_root[] = { 732 { 733 .procname = "hpet", 734 .maxlen = 0, 735 .mode = 0555, 736 .child = hpet_table, 737 }, 738 {} 739 }; 740 741 static ctl_table dev_root[] = { 742 { 743 .procname = "dev", 744 .maxlen = 0, 745 .mode = 0555, 746 .child = hpet_root, 747 }, 748 {} 749 }; 750 751 static struct ctl_table_header *sysctl_header; 752 753 /* 754 * Adjustment for when arming the timer with 755 * initial conditions. That is, main counter 756 * ticks expired before interrupts are enabled. 757 */ 758 #define TICK_CALIBRATE (1000UL) 759 760 static unsigned long __hpet_calibrate(struct hpets *hpetp) 761 { 762 struct hpet_timer __iomem *timer = NULL; 763 unsigned long t, m, count, i, flags, start; 764 struct hpet_dev *devp; 765 int j; 766 struct hpet __iomem *hpet; 767 768 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 769 if ((devp->hd_flags & HPET_OPEN) == 0) { 770 timer = devp->hd_timer; 771 break; 772 } 773 774 if (!timer) 775 return 0; 776 777 hpet = hpetp->hp_hpet; 778 t = read_counter(&timer->hpet_compare); 779 780 i = 0; 781 count = hpet_time_div(hpetp, TICK_CALIBRATE); 782 783 local_irq_save(flags); 784 785 start = read_counter(&hpet->hpet_mc); 786 787 do { 788 m = read_counter(&hpet->hpet_mc); 789 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 790 } while (i++, (m - start) < count); 791 792 local_irq_restore(flags); 793 794 return (m - start) / i; 795 } 796 797 static unsigned long hpet_calibrate(struct hpets *hpetp) 798 { 799 unsigned long ret = -1; 800 unsigned long tmp; 801 802 /* 803 * Try to calibrate until return value becomes stable small value. 804 * If SMI interruption occurs in calibration loop, the return value 805 * will be big. This avoids its impact. 806 */ 807 for ( ; ; ) { 808 tmp = __hpet_calibrate(hpetp); 809 if (ret <= tmp) 810 break; 811 ret = tmp; 812 } 813 814 return ret; 815 } 816 817 int hpet_alloc(struct hpet_data *hdp) 818 { 819 u64 cap, mcfg; 820 struct hpet_dev *devp; 821 u32 i, ntimer; 822 struct hpets *hpetp; 823 size_t siz; 824 struct hpet __iomem *hpet; 825 static struct hpets *last; 826 unsigned long period; 827 unsigned long long temp; 828 u32 remainder; 829 830 /* 831 * hpet_alloc can be called by platform dependent code. 832 * If platform dependent code has allocated the hpet that 833 * ACPI has also reported, then we catch it here. 834 */ 835 if (hpet_is_known(hdp)) { 836 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 837 __func__); 838 return 0; 839 } 840 841 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 842 sizeof(struct hpet_dev)); 843 844 hpetp = kzalloc(siz, GFP_KERNEL); 845 846 if (!hpetp) 847 return -ENOMEM; 848 849 hpetp->hp_which = hpet_nhpet++; 850 hpetp->hp_hpet = hdp->hd_address; 851 hpetp->hp_hpet_phys = hdp->hd_phys_address; 852 853 hpetp->hp_ntimer = hdp->hd_nirqs; 854 855 for (i = 0; i < hdp->hd_nirqs; i++) 856 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 857 858 hpet = hpetp->hp_hpet; 859 860 cap = readq(&hpet->hpet_cap); 861 862 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 863 864 if (hpetp->hp_ntimer != ntimer) { 865 printk(KERN_WARNING "hpet: number irqs doesn't agree" 866 " with number of timers\n"); 867 kfree(hpetp); 868 return -ENODEV; 869 } 870 871 if (last) 872 last->hp_next = hpetp; 873 else 874 hpets = hpetp; 875 876 last = hpetp; 877 878 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 879 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 880 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 881 temp += period >> 1; /* round */ 882 do_div(temp, period); 883 hpetp->hp_tick_freq = temp; /* ticks per second */ 884 885 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 886 hpetp->hp_which, hdp->hd_phys_address, 887 hpetp->hp_ntimer > 1 ? "s" : ""); 888 for (i = 0; i < hpetp->hp_ntimer; i++) 889 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 890 printk("\n"); 891 892 temp = hpetp->hp_tick_freq; 893 remainder = do_div(temp, 1000000); 894 printk(KERN_INFO 895 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", 896 hpetp->hp_which, hpetp->hp_ntimer, 897 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, 898 (unsigned) temp, remainder); 899 900 mcfg = readq(&hpet->hpet_config); 901 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 902 write_counter(0L, &hpet->hpet_mc); 903 mcfg |= HPET_ENABLE_CNF_MASK; 904 writeq(mcfg, &hpet->hpet_config); 905 } 906 907 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 908 struct hpet_timer __iomem *timer; 909 910 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 911 912 devp->hd_hpets = hpetp; 913 devp->hd_hpet = hpet; 914 devp->hd_timer = timer; 915 916 /* 917 * If the timer was reserved by platform code, 918 * then make timer unavailable for opens. 919 */ 920 if (hdp->hd_state & (1 << i)) { 921 devp->hd_flags = HPET_OPEN; 922 continue; 923 } 924 925 init_waitqueue_head(&devp->hd_waitqueue); 926 } 927 928 hpetp->hp_delta = hpet_calibrate(hpetp); 929 930 /* This clocksource driver currently only works on ia64 */ 931 #ifdef CONFIG_IA64 932 if (!hpet_clocksource) { 933 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 934 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); 935 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); 936 hpetp->hp_clocksource = &clocksource_hpet; 937 hpet_clocksource = &clocksource_hpet; 938 } 939 #endif 940 941 return 0; 942 } 943 944 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 945 { 946 struct hpet_data *hdp; 947 acpi_status status; 948 struct acpi_resource_address64 addr; 949 950 hdp = data; 951 952 status = acpi_resource_to_address64(res, &addr); 953 954 if (ACPI_SUCCESS(status)) { 955 hdp->hd_phys_address = addr.minimum; 956 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 957 958 if (hpet_is_known(hdp)) { 959 iounmap(hdp->hd_address); 960 return AE_ALREADY_EXISTS; 961 } 962 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 963 struct acpi_resource_fixed_memory32 *fixmem32; 964 965 fixmem32 = &res->data.fixed_memory32; 966 if (!fixmem32) 967 return AE_NO_MEMORY; 968 969 hdp->hd_phys_address = fixmem32->address; 970 hdp->hd_address = ioremap(fixmem32->address, 971 HPET_RANGE_SIZE); 972 973 if (hpet_is_known(hdp)) { 974 iounmap(hdp->hd_address); 975 return AE_ALREADY_EXISTS; 976 } 977 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 978 struct acpi_resource_extended_irq *irqp; 979 int i, irq; 980 981 irqp = &res->data.extended_irq; 982 983 for (i = 0; i < irqp->interrupt_count; i++) { 984 irq = acpi_register_gsi(NULL, irqp->interrupts[i], 985 irqp->triggering, irqp->polarity); 986 if (irq < 0) 987 return AE_ERROR; 988 989 hdp->hd_irq[hdp->hd_nirqs] = irq; 990 hdp->hd_nirqs++; 991 } 992 } 993 994 return AE_OK; 995 } 996 997 static int hpet_acpi_add(struct acpi_device *device) 998 { 999 acpi_status result; 1000 struct hpet_data data; 1001 1002 memset(&data, 0, sizeof(data)); 1003 1004 result = 1005 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 1006 hpet_resources, &data); 1007 1008 if (ACPI_FAILURE(result)) 1009 return -ENODEV; 1010 1011 if (!data.hd_address || !data.hd_nirqs) { 1012 if (data.hd_address) 1013 iounmap(data.hd_address); 1014 printk("%s: no address or irqs in _CRS\n", __func__); 1015 return -ENODEV; 1016 } 1017 1018 return hpet_alloc(&data); 1019 } 1020 1021 static int hpet_acpi_remove(struct acpi_device *device, int type) 1022 { 1023 /* XXX need to unregister clocksource, dealloc mem, etc */ 1024 return -EINVAL; 1025 } 1026 1027 static const struct acpi_device_id hpet_device_ids[] = { 1028 {"PNP0103", 0}, 1029 {"", 0}, 1030 }; 1031 MODULE_DEVICE_TABLE(acpi, hpet_device_ids); 1032 1033 static struct acpi_driver hpet_acpi_driver = { 1034 .name = "hpet", 1035 .ids = hpet_device_ids, 1036 .ops = { 1037 .add = hpet_acpi_add, 1038 .remove = hpet_acpi_remove, 1039 }, 1040 }; 1041 1042 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1043 1044 static int __init hpet_init(void) 1045 { 1046 int result; 1047 1048 result = misc_register(&hpet_misc); 1049 if (result < 0) 1050 return -ENODEV; 1051 1052 sysctl_header = register_sysctl_table(dev_root); 1053 1054 result = acpi_bus_register_driver(&hpet_acpi_driver); 1055 if (result < 0) { 1056 if (sysctl_header) 1057 unregister_sysctl_table(sysctl_header); 1058 misc_deregister(&hpet_misc); 1059 return result; 1060 } 1061 1062 return 0; 1063 } 1064 1065 static void __exit hpet_exit(void) 1066 { 1067 acpi_bus_unregister_driver(&hpet_acpi_driver); 1068 1069 if (sysctl_header) 1070 unregister_sysctl_table(sysctl_header); 1071 misc_deregister(&hpet_misc); 1072 1073 return; 1074 } 1075 1076 module_init(hpet_init); 1077 module_exit(hpet_exit); 1078 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1079 MODULE_LICENSE("GPL"); 1080