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 .mult = 0, /* to be calculated */ 88 .shift = 10, 89 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 90 }; 91 static struct clocksource *hpet_clocksource; 92 #endif 93 94 /* A lock for concurrent access by app and isr hpet activity. */ 95 static DEFINE_SPINLOCK(hpet_lock); 96 97 #define HPET_DEV_NAME (7) 98 99 struct hpet_dev { 100 struct hpets *hd_hpets; 101 struct hpet __iomem *hd_hpet; 102 struct hpet_timer __iomem *hd_timer; 103 unsigned long hd_ireqfreq; 104 unsigned long hd_irqdata; 105 wait_queue_head_t hd_waitqueue; 106 struct fasync_struct *hd_async_queue; 107 unsigned int hd_flags; 108 unsigned int hd_irq; 109 unsigned int hd_hdwirq; 110 char hd_name[HPET_DEV_NAME]; 111 }; 112 113 struct hpets { 114 struct hpets *hp_next; 115 struct hpet __iomem *hp_hpet; 116 unsigned long hp_hpet_phys; 117 struct clocksource *hp_clocksource; 118 unsigned long long hp_tick_freq; 119 unsigned long hp_delta; 120 unsigned int hp_ntimer; 121 unsigned int hp_which; 122 struct hpet_dev hp_dev[1]; 123 }; 124 125 static struct hpets *hpets; 126 127 #define HPET_OPEN 0x0001 128 #define HPET_IE 0x0002 /* interrupt enabled */ 129 #define HPET_PERIODIC 0x0004 130 #define HPET_SHARED_IRQ 0x0008 131 132 133 #ifndef readq 134 static inline unsigned long long readq(void __iomem *addr) 135 { 136 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 137 } 138 #endif 139 140 #ifndef writeq 141 static inline void writeq(unsigned long long v, void __iomem *addr) 142 { 143 writel(v & 0xffffffff, addr); 144 writel(v >> 32, addr + 4); 145 } 146 #endif 147 148 static irqreturn_t hpet_interrupt(int irq, void *data) 149 { 150 struct hpet_dev *devp; 151 unsigned long isr; 152 153 devp = data; 154 isr = 1 << (devp - devp->hd_hpets->hp_dev); 155 156 if ((devp->hd_flags & HPET_SHARED_IRQ) && 157 !(isr & readl(&devp->hd_hpet->hpet_isr))) 158 return IRQ_NONE; 159 160 spin_lock(&hpet_lock); 161 devp->hd_irqdata++; 162 163 /* 164 * For non-periodic timers, increment the accumulator. 165 * This has the effect of treating non-periodic like periodic. 166 */ 167 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 168 unsigned long m, t; 169 170 t = devp->hd_ireqfreq; 171 m = read_counter(&devp->hd_timer->hpet_compare); 172 write_counter(t + m, &devp->hd_timer->hpet_compare); 173 } 174 175 if (devp->hd_flags & HPET_SHARED_IRQ) 176 writel(isr, &devp->hd_hpet->hpet_isr); 177 spin_unlock(&hpet_lock); 178 179 wake_up_interruptible(&devp->hd_waitqueue); 180 181 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 182 183 return IRQ_HANDLED; 184 } 185 186 static void hpet_timer_set_irq(struct hpet_dev *devp) 187 { 188 unsigned long v; 189 int irq, gsi; 190 struct hpet_timer __iomem *timer; 191 192 spin_lock_irq(&hpet_lock); 193 if (devp->hd_hdwirq) { 194 spin_unlock_irq(&hpet_lock); 195 return; 196 } 197 198 timer = devp->hd_timer; 199 200 /* we prefer level triggered mode */ 201 v = readl(&timer->hpet_config); 202 if (!(v & Tn_INT_TYPE_CNF_MASK)) { 203 v |= Tn_INT_TYPE_CNF_MASK; 204 writel(v, &timer->hpet_config); 205 } 206 spin_unlock_irq(&hpet_lock); 207 208 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> 209 Tn_INT_ROUTE_CAP_SHIFT; 210 211 /* 212 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by 213 * legacy device. In IO APIC mode, we skip all the legacy IRQS. 214 */ 215 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) 216 v &= ~0xf3df; 217 else 218 v &= ~0xffff; 219 220 for_each_set_bit(irq, &v, HPET_MAX_IRQ) { 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 mutex_lock(&hpet_mutex); 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 mutex_unlock(&hpet_mutex); 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 mutex_unlock(&hpet_mutex); 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_ieon(struct hpet_dev *devp) 434 { 435 struct hpet_timer __iomem *timer; 436 struct hpet __iomem *hpet; 437 struct hpets *hpetp; 438 int irq; 439 unsigned long g, v, t, m; 440 unsigned long flags, isr; 441 442 timer = devp->hd_timer; 443 hpet = devp->hd_hpet; 444 hpetp = devp->hd_hpets; 445 446 if (!devp->hd_ireqfreq) 447 return -EIO; 448 449 spin_lock_irq(&hpet_lock); 450 451 if (devp->hd_flags & HPET_IE) { 452 spin_unlock_irq(&hpet_lock); 453 return -EBUSY; 454 } 455 456 devp->hd_flags |= HPET_IE; 457 458 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 459 devp->hd_flags |= HPET_SHARED_IRQ; 460 spin_unlock_irq(&hpet_lock); 461 462 irq = devp->hd_hdwirq; 463 464 if (irq) { 465 unsigned long irq_flags; 466 467 if (devp->hd_flags & HPET_SHARED_IRQ) { 468 /* 469 * To prevent the interrupt handler from seeing an 470 * unwanted interrupt status bit, program the timer 471 * so that it will not fire in the near future ... 472 */ 473 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, 474 &timer->hpet_config); 475 write_counter(read_counter(&hpet->hpet_mc), 476 &timer->hpet_compare); 477 /* ... and clear any left-over status. */ 478 isr = 1 << (devp - devp->hd_hpets->hp_dev); 479 writel(isr, &hpet->hpet_isr); 480 } 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, 557 struct hpet_info *info) 558 { 559 struct hpet_timer __iomem *timer; 560 struct hpet __iomem *hpet; 561 struct hpets *hpetp; 562 int err; 563 unsigned long v; 564 565 switch (cmd) { 566 case HPET_IE_OFF: 567 case HPET_INFO: 568 case HPET_EPI: 569 case HPET_DPI: 570 case HPET_IRQFREQ: 571 timer = devp->hd_timer; 572 hpet = devp->hd_hpet; 573 hpetp = devp->hd_hpets; 574 break; 575 case HPET_IE_ON: 576 return hpet_ioctl_ieon(devp); 577 default: 578 return -EINVAL; 579 } 580 581 err = 0; 582 583 switch (cmd) { 584 case HPET_IE_OFF: 585 if ((devp->hd_flags & HPET_IE) == 0) 586 break; 587 v = readq(&timer->hpet_config); 588 v &= ~Tn_INT_ENB_CNF_MASK; 589 writeq(v, &timer->hpet_config); 590 if (devp->hd_irq) { 591 free_irq(devp->hd_irq, devp); 592 devp->hd_irq = 0; 593 } 594 devp->hd_flags ^= HPET_IE; 595 break; 596 case HPET_INFO: 597 { 598 memset(info, 0, sizeof(*info)); 599 if (devp->hd_ireqfreq) 600 info->hi_ireqfreq = 601 hpet_time_div(hpetp, devp->hd_ireqfreq); 602 info->hi_flags = 603 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 604 info->hi_hpet = hpetp->hp_which; 605 info->hi_timer = devp - hpetp->hp_dev; 606 break; 607 } 608 case HPET_EPI: 609 v = readq(&timer->hpet_config); 610 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 611 err = -ENXIO; 612 break; 613 } 614 devp->hd_flags |= HPET_PERIODIC; 615 break; 616 case HPET_DPI: 617 v = readq(&timer->hpet_config); 618 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 619 err = -ENXIO; 620 break; 621 } 622 if (devp->hd_flags & HPET_PERIODIC && 623 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 624 v = readq(&timer->hpet_config); 625 v ^= Tn_TYPE_CNF_MASK; 626 writeq(v, &timer->hpet_config); 627 } 628 devp->hd_flags &= ~HPET_PERIODIC; 629 break; 630 case HPET_IRQFREQ: 631 if ((arg > hpet_max_freq) && 632 !capable(CAP_SYS_RESOURCE)) { 633 err = -EACCES; 634 break; 635 } 636 637 if (!arg) { 638 err = -EINVAL; 639 break; 640 } 641 642 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 643 } 644 645 return err; 646 } 647 648 static long 649 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 650 { 651 struct hpet_info info; 652 int err; 653 654 mutex_lock(&hpet_mutex); 655 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 656 mutex_unlock(&hpet_mutex); 657 658 if ((cmd == HPET_INFO) && !err && 659 (copy_to_user((void __user *)arg, &info, sizeof(info)))) 660 err = -EFAULT; 661 662 return err; 663 } 664 665 #ifdef CONFIG_COMPAT 666 struct compat_hpet_info { 667 compat_ulong_t hi_ireqfreq; /* Hz */ 668 compat_ulong_t hi_flags; /* information */ 669 unsigned short hi_hpet; 670 unsigned short hi_timer; 671 }; 672 673 static long 674 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 675 { 676 struct hpet_info info; 677 int err; 678 679 mutex_lock(&hpet_mutex); 680 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 681 mutex_unlock(&hpet_mutex); 682 683 if ((cmd == HPET_INFO) && !err) { 684 struct compat_hpet_info __user *u = compat_ptr(arg); 685 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) || 686 put_user(info.hi_flags, &u->hi_flags) || 687 put_user(info.hi_hpet, &u->hi_hpet) || 688 put_user(info.hi_timer, &u->hi_timer)) 689 err = -EFAULT; 690 } 691 692 return err; 693 } 694 #endif 695 696 static const struct file_operations hpet_fops = { 697 .owner = THIS_MODULE, 698 .llseek = no_llseek, 699 .read = hpet_read, 700 .poll = hpet_poll, 701 .unlocked_ioctl = hpet_ioctl, 702 #ifdef CONFIG_COMPAT 703 .compat_ioctl = hpet_compat_ioctl, 704 #endif 705 .open = hpet_open, 706 .release = hpet_release, 707 .fasync = hpet_fasync, 708 .mmap = hpet_mmap, 709 }; 710 711 static int hpet_is_known(struct hpet_data *hdp) 712 { 713 struct hpets *hpetp; 714 715 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 716 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 717 return 1; 718 719 return 0; 720 } 721 722 static ctl_table hpet_table[] = { 723 { 724 .procname = "max-user-freq", 725 .data = &hpet_max_freq, 726 .maxlen = sizeof(int), 727 .mode = 0644, 728 .proc_handler = proc_dointvec, 729 }, 730 {} 731 }; 732 733 static ctl_table hpet_root[] = { 734 { 735 .procname = "hpet", 736 .maxlen = 0, 737 .mode = 0555, 738 .child = hpet_table, 739 }, 740 {} 741 }; 742 743 static ctl_table dev_root[] = { 744 { 745 .procname = "dev", 746 .maxlen = 0, 747 .mode = 0555, 748 .child = hpet_root, 749 }, 750 {} 751 }; 752 753 static struct ctl_table_header *sysctl_header; 754 755 /* 756 * Adjustment for when arming the timer with 757 * initial conditions. That is, main counter 758 * ticks expired before interrupts are enabled. 759 */ 760 #define TICK_CALIBRATE (1000UL) 761 762 static unsigned long __hpet_calibrate(struct hpets *hpetp) 763 { 764 struct hpet_timer __iomem *timer = NULL; 765 unsigned long t, m, count, i, flags, start; 766 struct hpet_dev *devp; 767 int j; 768 struct hpet __iomem *hpet; 769 770 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 771 if ((devp->hd_flags & HPET_OPEN) == 0) { 772 timer = devp->hd_timer; 773 break; 774 } 775 776 if (!timer) 777 return 0; 778 779 hpet = hpetp->hp_hpet; 780 t = read_counter(&timer->hpet_compare); 781 782 i = 0; 783 count = hpet_time_div(hpetp, TICK_CALIBRATE); 784 785 local_irq_save(flags); 786 787 start = read_counter(&hpet->hpet_mc); 788 789 do { 790 m = read_counter(&hpet->hpet_mc); 791 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 792 } while (i++, (m - start) < count); 793 794 local_irq_restore(flags); 795 796 return (m - start) / i; 797 } 798 799 static unsigned long hpet_calibrate(struct hpets *hpetp) 800 { 801 unsigned long ret = -1; 802 unsigned long tmp; 803 804 /* 805 * Try to calibrate until return value becomes stable small value. 806 * If SMI interruption occurs in calibration loop, the return value 807 * will be big. This avoids its impact. 808 */ 809 for ( ; ; ) { 810 tmp = __hpet_calibrate(hpetp); 811 if (ret <= tmp) 812 break; 813 ret = tmp; 814 } 815 816 return ret; 817 } 818 819 int hpet_alloc(struct hpet_data *hdp) 820 { 821 u64 cap, mcfg; 822 struct hpet_dev *devp; 823 u32 i, ntimer; 824 struct hpets *hpetp; 825 size_t siz; 826 struct hpet __iomem *hpet; 827 static struct hpets *last; 828 unsigned long period; 829 unsigned long long temp; 830 u32 remainder; 831 832 /* 833 * hpet_alloc can be called by platform dependent code. 834 * If platform dependent code has allocated the hpet that 835 * ACPI has also reported, then we catch it here. 836 */ 837 if (hpet_is_known(hdp)) { 838 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 839 __func__); 840 return 0; 841 } 842 843 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 844 sizeof(struct hpet_dev)); 845 846 hpetp = kzalloc(siz, GFP_KERNEL); 847 848 if (!hpetp) 849 return -ENOMEM; 850 851 hpetp->hp_which = hpet_nhpet++; 852 hpetp->hp_hpet = hdp->hd_address; 853 hpetp->hp_hpet_phys = hdp->hd_phys_address; 854 855 hpetp->hp_ntimer = hdp->hd_nirqs; 856 857 for (i = 0; i < hdp->hd_nirqs; i++) 858 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 859 860 hpet = hpetp->hp_hpet; 861 862 cap = readq(&hpet->hpet_cap); 863 864 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 865 866 if (hpetp->hp_ntimer != ntimer) { 867 printk(KERN_WARNING "hpet: number irqs doesn't agree" 868 " with number of timers\n"); 869 kfree(hpetp); 870 return -ENODEV; 871 } 872 873 if (last) 874 last->hp_next = hpetp; 875 else 876 hpets = hpetp; 877 878 last = hpetp; 879 880 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 881 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 882 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 883 temp += period >> 1; /* round */ 884 do_div(temp, period); 885 hpetp->hp_tick_freq = temp; /* ticks per second */ 886 887 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 888 hpetp->hp_which, hdp->hd_phys_address, 889 hpetp->hp_ntimer > 1 ? "s" : ""); 890 for (i = 0; i < hpetp->hp_ntimer; i++) 891 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 892 printk("\n"); 893 894 temp = hpetp->hp_tick_freq; 895 remainder = do_div(temp, 1000000); 896 printk(KERN_INFO 897 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", 898 hpetp->hp_which, hpetp->hp_ntimer, 899 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, 900 (unsigned) temp, remainder); 901 902 mcfg = readq(&hpet->hpet_config); 903 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 904 write_counter(0L, &hpet->hpet_mc); 905 mcfg |= HPET_ENABLE_CNF_MASK; 906 writeq(mcfg, &hpet->hpet_config); 907 } 908 909 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 910 struct hpet_timer __iomem *timer; 911 912 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 913 914 devp->hd_hpets = hpetp; 915 devp->hd_hpet = hpet; 916 devp->hd_timer = timer; 917 918 /* 919 * If the timer was reserved by platform code, 920 * then make timer unavailable for opens. 921 */ 922 if (hdp->hd_state & (1 << i)) { 923 devp->hd_flags = HPET_OPEN; 924 continue; 925 } 926 927 init_waitqueue_head(&devp->hd_waitqueue); 928 } 929 930 hpetp->hp_delta = hpet_calibrate(hpetp); 931 932 /* This clocksource driver currently only works on ia64 */ 933 #ifdef CONFIG_IA64 934 if (!hpet_clocksource) { 935 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 936 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); 937 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, 938 clocksource_hpet.shift); 939 clocksource_register(&clocksource_hpet); 940 hpetp->hp_clocksource = &clocksource_hpet; 941 hpet_clocksource = &clocksource_hpet; 942 } 943 #endif 944 945 return 0; 946 } 947 948 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 949 { 950 struct hpet_data *hdp; 951 acpi_status status; 952 struct acpi_resource_address64 addr; 953 954 hdp = data; 955 956 status = acpi_resource_to_address64(res, &addr); 957 958 if (ACPI_SUCCESS(status)) { 959 hdp->hd_phys_address = addr.minimum; 960 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 961 962 if (hpet_is_known(hdp)) { 963 iounmap(hdp->hd_address); 964 return AE_ALREADY_EXISTS; 965 } 966 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 967 struct acpi_resource_fixed_memory32 *fixmem32; 968 969 fixmem32 = &res->data.fixed_memory32; 970 if (!fixmem32) 971 return AE_NO_MEMORY; 972 973 hdp->hd_phys_address = fixmem32->address; 974 hdp->hd_address = ioremap(fixmem32->address, 975 HPET_RANGE_SIZE); 976 977 if (hpet_is_known(hdp)) { 978 iounmap(hdp->hd_address); 979 return AE_ALREADY_EXISTS; 980 } 981 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 982 struct acpi_resource_extended_irq *irqp; 983 int i, irq; 984 985 irqp = &res->data.extended_irq; 986 987 for (i = 0; i < irqp->interrupt_count; i++) { 988 irq = acpi_register_gsi(NULL, irqp->interrupts[i], 989 irqp->triggering, irqp->polarity); 990 if (irq < 0) 991 return AE_ERROR; 992 993 hdp->hd_irq[hdp->hd_nirqs] = irq; 994 hdp->hd_nirqs++; 995 } 996 } 997 998 return AE_OK; 999 } 1000 1001 static int hpet_acpi_add(struct acpi_device *device) 1002 { 1003 acpi_status result; 1004 struct hpet_data data; 1005 1006 memset(&data, 0, sizeof(data)); 1007 1008 result = 1009 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 1010 hpet_resources, &data); 1011 1012 if (ACPI_FAILURE(result)) 1013 return -ENODEV; 1014 1015 if (!data.hd_address || !data.hd_nirqs) { 1016 if (data.hd_address) 1017 iounmap(data.hd_address); 1018 printk("%s: no address or irqs in _CRS\n", __func__); 1019 return -ENODEV; 1020 } 1021 1022 return hpet_alloc(&data); 1023 } 1024 1025 static int hpet_acpi_remove(struct acpi_device *device, int type) 1026 { 1027 /* XXX need to unregister clocksource, dealloc mem, etc */ 1028 return -EINVAL; 1029 } 1030 1031 static const struct acpi_device_id hpet_device_ids[] = { 1032 {"PNP0103", 0}, 1033 {"", 0}, 1034 }; 1035 MODULE_DEVICE_TABLE(acpi, hpet_device_ids); 1036 1037 static struct acpi_driver hpet_acpi_driver = { 1038 .name = "hpet", 1039 .ids = hpet_device_ids, 1040 .ops = { 1041 .add = hpet_acpi_add, 1042 .remove = hpet_acpi_remove, 1043 }, 1044 }; 1045 1046 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1047 1048 static int __init hpet_init(void) 1049 { 1050 int result; 1051 1052 result = misc_register(&hpet_misc); 1053 if (result < 0) 1054 return -ENODEV; 1055 1056 sysctl_header = register_sysctl_table(dev_root); 1057 1058 result = acpi_bus_register_driver(&hpet_acpi_driver); 1059 if (result < 0) { 1060 if (sysctl_header) 1061 unregister_sysctl_table(sysctl_header); 1062 misc_deregister(&hpet_misc); 1063 return result; 1064 } 1065 1066 return 0; 1067 } 1068 1069 static void __exit hpet_exit(void) 1070 { 1071 acpi_bus_unregister_driver(&hpet_acpi_driver); 1072 1073 if (sysctl_header) 1074 unregister_sysctl_table(sysctl_header); 1075 misc_deregister(&hpet_misc); 1076 1077 return; 1078 } 1079 1080 module_init(hpet_init); 1081 module_exit(hpet_exit); 1082 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1083 MODULE_LICENSE("GPL"); 1084