1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Intel & MS High Precision Event Timer Implementation. 4 * 5 * Copyright (C) 2003 Intel Corporation 6 * Venki Pallipadi 7 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. 8 * Bob Picco <robert.picco@hp.com> 9 */ 10 11 #include <linux/interrupt.h> 12 #include <linux/kernel.h> 13 #include <linux/types.h> 14 #include <linux/miscdevice.h> 15 #include <linux/major.h> 16 #include <linux/ioport.h> 17 #include <linux/fcntl.h> 18 #include <linux/init.h> 19 #include <linux/poll.h> 20 #include <linux/mm.h> 21 #include <linux/proc_fs.h> 22 #include <linux/spinlock.h> 23 #include <linux/sysctl.h> 24 #include <linux/wait.h> 25 #include <linux/sched/signal.h> 26 #include <linux/bcd.h> 27 #include <linux/seq_file.h> 28 #include <linux/bitops.h> 29 #include <linux/compat.h> 30 #include <linux/clocksource.h> 31 #include <linux/uaccess.h> 32 #include <linux/slab.h> 33 #include <linux/io.h> 34 #include <linux/acpi.h> 35 #include <linux/hpet.h> 36 #include <asm/current.h> 37 #include <asm/irq.h> 38 #include <asm/div64.h> 39 40 /* 41 * The High Precision Event Timer driver. 42 * This driver is closely modelled after the rtc.c driver. 43 * See HPET spec revision 1. 44 */ 45 #define HPET_USER_FREQ (64) 46 #define HPET_DRIFT (500) 47 48 #define HPET_RANGE_SIZE 1024 /* from HPET spec */ 49 50 51 /* WARNING -- don't get confused. These macros are never used 52 * to write the (single) counter, and rarely to read it. 53 * They're badly named; to fix, someday. 54 */ 55 #if BITS_PER_LONG == 64 56 #define write_counter(V, MC) writeq(V, MC) 57 #define read_counter(MC) readq(MC) 58 #else 59 #define write_counter(V, MC) writel(V, MC) 60 #define read_counter(MC) readl(MC) 61 #endif 62 63 static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */ 64 static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 65 66 /* This clocksource driver currently only works on ia64 */ 67 #ifdef CONFIG_IA64 68 static void __iomem *hpet_mctr; 69 70 static u64 read_hpet(struct clocksource *cs) 71 { 72 return (u64)read_counter((void __iomem *)hpet_mctr); 73 } 74 75 static struct clocksource clocksource_hpet = { 76 .name = "hpet", 77 .rating = 250, 78 .read = read_hpet, 79 .mask = CLOCKSOURCE_MASK(64), 80 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 81 }; 82 static struct clocksource *hpet_clocksource; 83 #endif 84 85 /* A lock for concurrent access by app and isr hpet activity. */ 86 static DEFINE_SPINLOCK(hpet_lock); 87 88 #define HPET_DEV_NAME (7) 89 90 struct hpet_dev { 91 struct hpets *hd_hpets; 92 struct hpet __iomem *hd_hpet; 93 struct hpet_timer __iomem *hd_timer; 94 unsigned long hd_ireqfreq; 95 unsigned long hd_irqdata; 96 wait_queue_head_t hd_waitqueue; 97 struct fasync_struct *hd_async_queue; 98 unsigned int hd_flags; 99 unsigned int hd_irq; 100 unsigned int hd_hdwirq; 101 char hd_name[HPET_DEV_NAME]; 102 }; 103 104 struct hpets { 105 struct hpets *hp_next; 106 struct hpet __iomem *hp_hpet; 107 unsigned long hp_hpet_phys; 108 struct clocksource *hp_clocksource; 109 unsigned long long hp_tick_freq; 110 unsigned long hp_delta; 111 unsigned int hp_ntimer; 112 unsigned int hp_which; 113 struct hpet_dev hp_dev[]; 114 }; 115 116 static struct hpets *hpets; 117 118 #define HPET_OPEN 0x0001 119 #define HPET_IE 0x0002 /* interrupt enabled */ 120 #define HPET_PERIODIC 0x0004 121 #define HPET_SHARED_IRQ 0x0008 122 123 124 #ifndef readq 125 static inline unsigned long long readq(void __iomem *addr) 126 { 127 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 128 } 129 #endif 130 131 #ifndef writeq 132 static inline void writeq(unsigned long long v, void __iomem *addr) 133 { 134 writel(v & 0xffffffff, addr); 135 writel(v >> 32, addr + 4); 136 } 137 #endif 138 139 static irqreturn_t hpet_interrupt(int irq, void *data) 140 { 141 struct hpet_dev *devp; 142 unsigned long isr; 143 144 devp = data; 145 isr = 1 << (devp - devp->hd_hpets->hp_dev); 146 147 if ((devp->hd_flags & HPET_SHARED_IRQ) && 148 !(isr & readl(&devp->hd_hpet->hpet_isr))) 149 return IRQ_NONE; 150 151 spin_lock(&hpet_lock); 152 devp->hd_irqdata++; 153 154 /* 155 * For non-periodic timers, increment the accumulator. 156 * This has the effect of treating non-periodic like periodic. 157 */ 158 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 159 unsigned long t, mc, base, k; 160 struct hpet __iomem *hpet = devp->hd_hpet; 161 struct hpets *hpetp = devp->hd_hpets; 162 163 t = devp->hd_ireqfreq; 164 read_counter(&devp->hd_timer->hpet_compare); 165 mc = read_counter(&hpet->hpet_mc); 166 /* The time for the next interrupt would logically be t + m, 167 * however, if we are very unlucky and the interrupt is delayed 168 * for longer than t then we will completely miss the next 169 * interrupt if we set t + m and an application will hang. 170 * Therefore we need to make a more complex computation assuming 171 * that there exists a k for which the following is true: 172 * k * t + base < mc + delta 173 * (k + 1) * t + base > mc + delta 174 * where t is the interval in hpet ticks for the given freq, 175 * base is the theoretical start value 0 < base < t, 176 * mc is the main counter value at the time of the interrupt, 177 * delta is the time it takes to write the a value to the 178 * comparator. 179 * k may then be computed as (mc - base + delta) / t . 180 */ 181 base = mc % t; 182 k = (mc - base + hpetp->hp_delta) / t; 183 write_counter(t * (k + 1) + base, 184 &devp->hd_timer->hpet_compare); 185 } 186 187 if (devp->hd_flags & HPET_SHARED_IRQ) 188 writel(isr, &devp->hd_hpet->hpet_isr); 189 spin_unlock(&hpet_lock); 190 191 wake_up_interruptible(&devp->hd_waitqueue); 192 193 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 194 195 return IRQ_HANDLED; 196 } 197 198 static void hpet_timer_set_irq(struct hpet_dev *devp) 199 { 200 unsigned long v; 201 int irq, gsi; 202 struct hpet_timer __iomem *timer; 203 204 spin_lock_irq(&hpet_lock); 205 if (devp->hd_hdwirq) { 206 spin_unlock_irq(&hpet_lock); 207 return; 208 } 209 210 timer = devp->hd_timer; 211 212 /* we prefer level triggered mode */ 213 v = readl(&timer->hpet_config); 214 if (!(v & Tn_INT_TYPE_CNF_MASK)) { 215 v |= Tn_INT_TYPE_CNF_MASK; 216 writel(v, &timer->hpet_config); 217 } 218 spin_unlock_irq(&hpet_lock); 219 220 v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >> 221 Tn_INT_ROUTE_CAP_SHIFT; 222 223 /* 224 * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by 225 * legacy device. In IO APIC mode, we skip all the legacy IRQS. 226 */ 227 if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) 228 v &= ~0xf3df; 229 else 230 v &= ~0xffff; 231 232 for_each_set_bit(irq, &v, HPET_MAX_IRQ) { 233 if (irq >= nr_irqs) { 234 irq = HPET_MAX_IRQ; 235 break; 236 } 237 238 gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, 239 ACPI_ACTIVE_LOW); 240 if (gsi > 0) 241 break; 242 243 /* FIXME: Setup interrupt source table */ 244 } 245 246 if (irq < HPET_MAX_IRQ) { 247 spin_lock_irq(&hpet_lock); 248 v = readl(&timer->hpet_config); 249 v |= irq << Tn_INT_ROUTE_CNF_SHIFT; 250 writel(v, &timer->hpet_config); 251 devp->hd_hdwirq = gsi; 252 spin_unlock_irq(&hpet_lock); 253 } 254 return; 255 } 256 257 static int hpet_open(struct inode *inode, struct file *file) 258 { 259 struct hpet_dev *devp; 260 struct hpets *hpetp; 261 int i; 262 263 if (file->f_mode & FMODE_WRITE) 264 return -EINVAL; 265 266 mutex_lock(&hpet_mutex); 267 spin_lock_irq(&hpet_lock); 268 269 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 270 for (i = 0; i < hpetp->hp_ntimer; i++) 271 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN) 272 continue; 273 else { 274 devp = &hpetp->hp_dev[i]; 275 break; 276 } 277 278 if (!devp) { 279 spin_unlock_irq(&hpet_lock); 280 mutex_unlock(&hpet_mutex); 281 return -EBUSY; 282 } 283 284 file->private_data = devp; 285 devp->hd_irqdata = 0; 286 devp->hd_flags |= HPET_OPEN; 287 spin_unlock_irq(&hpet_lock); 288 mutex_unlock(&hpet_mutex); 289 290 hpet_timer_set_irq(devp); 291 292 return 0; 293 } 294 295 static ssize_t 296 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 297 { 298 DECLARE_WAITQUEUE(wait, current); 299 unsigned long data; 300 ssize_t retval; 301 struct hpet_dev *devp; 302 303 devp = file->private_data; 304 if (!devp->hd_ireqfreq) 305 return -EIO; 306 307 if (count < sizeof(unsigned long)) 308 return -EINVAL; 309 310 add_wait_queue(&devp->hd_waitqueue, &wait); 311 312 for ( ; ; ) { 313 set_current_state(TASK_INTERRUPTIBLE); 314 315 spin_lock_irq(&hpet_lock); 316 data = devp->hd_irqdata; 317 devp->hd_irqdata = 0; 318 spin_unlock_irq(&hpet_lock); 319 320 if (data) 321 break; 322 else if (file->f_flags & O_NONBLOCK) { 323 retval = -EAGAIN; 324 goto out; 325 } else if (signal_pending(current)) { 326 retval = -ERESTARTSYS; 327 goto out; 328 } 329 schedule(); 330 } 331 332 retval = put_user(data, (unsigned long __user *)buf); 333 if (!retval) 334 retval = sizeof(unsigned long); 335 out: 336 __set_current_state(TASK_RUNNING); 337 remove_wait_queue(&devp->hd_waitqueue, &wait); 338 339 return retval; 340 } 341 342 static __poll_t hpet_poll(struct file *file, poll_table * wait) 343 { 344 unsigned long v; 345 struct hpet_dev *devp; 346 347 devp = file->private_data; 348 349 if (!devp->hd_ireqfreq) 350 return 0; 351 352 poll_wait(file, &devp->hd_waitqueue, wait); 353 354 spin_lock_irq(&hpet_lock); 355 v = devp->hd_irqdata; 356 spin_unlock_irq(&hpet_lock); 357 358 if (v != 0) 359 return EPOLLIN | EPOLLRDNORM; 360 361 return 0; 362 } 363 364 #ifdef CONFIG_HPET_MMAP 365 #ifdef CONFIG_HPET_MMAP_DEFAULT 366 static int hpet_mmap_enabled = 1; 367 #else 368 static int hpet_mmap_enabled = 0; 369 #endif 370 371 static __init int hpet_mmap_enable(char *str) 372 { 373 get_option(&str, &hpet_mmap_enabled); 374 pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled"); 375 return 1; 376 } 377 __setup("hpet_mmap=", hpet_mmap_enable); 378 379 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 380 { 381 struct hpet_dev *devp; 382 unsigned long addr; 383 384 if (!hpet_mmap_enabled) 385 return -EACCES; 386 387 devp = file->private_data; 388 addr = devp->hd_hpets->hp_hpet_phys; 389 390 if (addr & (PAGE_SIZE - 1)) 391 return -ENOSYS; 392 393 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 394 return vm_iomap_memory(vma, addr, PAGE_SIZE); 395 } 396 #else 397 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 398 { 399 return -ENOSYS; 400 } 401 #endif 402 403 static int hpet_fasync(int fd, struct file *file, int on) 404 { 405 struct hpet_dev *devp; 406 407 devp = file->private_data; 408 409 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 410 return 0; 411 else 412 return -EIO; 413 } 414 415 static int hpet_release(struct inode *inode, struct file *file) 416 { 417 struct hpet_dev *devp; 418 struct hpet_timer __iomem *timer; 419 int irq = 0; 420 421 devp = file->private_data; 422 timer = devp->hd_timer; 423 424 spin_lock_irq(&hpet_lock); 425 426 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 427 &timer->hpet_config); 428 429 irq = devp->hd_irq; 430 devp->hd_irq = 0; 431 432 devp->hd_ireqfreq = 0; 433 434 if (devp->hd_flags & HPET_PERIODIC 435 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 436 unsigned long v; 437 438 v = readq(&timer->hpet_config); 439 v ^= Tn_TYPE_CNF_MASK; 440 writeq(v, &timer->hpet_config); 441 } 442 443 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 444 spin_unlock_irq(&hpet_lock); 445 446 if (irq) 447 free_irq(irq, devp); 448 449 file->private_data = NULL; 450 return 0; 451 } 452 453 static int hpet_ioctl_ieon(struct hpet_dev *devp) 454 { 455 struct hpet_timer __iomem *timer; 456 struct hpet __iomem *hpet; 457 struct hpets *hpetp; 458 int irq; 459 unsigned long g, v, t, m; 460 unsigned long flags, isr; 461 462 timer = devp->hd_timer; 463 hpet = devp->hd_hpet; 464 hpetp = devp->hd_hpets; 465 466 if (!devp->hd_ireqfreq) 467 return -EIO; 468 469 spin_lock_irq(&hpet_lock); 470 471 if (devp->hd_flags & HPET_IE) { 472 spin_unlock_irq(&hpet_lock); 473 return -EBUSY; 474 } 475 476 devp->hd_flags |= HPET_IE; 477 478 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 479 devp->hd_flags |= HPET_SHARED_IRQ; 480 spin_unlock_irq(&hpet_lock); 481 482 irq = devp->hd_hdwirq; 483 484 if (irq) { 485 unsigned long irq_flags; 486 487 if (devp->hd_flags & HPET_SHARED_IRQ) { 488 /* 489 * To prevent the interrupt handler from seeing an 490 * unwanted interrupt status bit, program the timer 491 * so that it will not fire in the near future ... 492 */ 493 writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, 494 &timer->hpet_config); 495 write_counter(read_counter(&hpet->hpet_mc), 496 &timer->hpet_compare); 497 /* ... and clear any left-over status. */ 498 isr = 1 << (devp - devp->hd_hpets->hp_dev); 499 writel(isr, &hpet->hpet_isr); 500 } 501 502 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 503 irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0; 504 if (request_irq(irq, hpet_interrupt, irq_flags, 505 devp->hd_name, (void *)devp)) { 506 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 507 irq = 0; 508 } 509 } 510 511 if (irq == 0) { 512 spin_lock_irq(&hpet_lock); 513 devp->hd_flags ^= HPET_IE; 514 spin_unlock_irq(&hpet_lock); 515 return -EIO; 516 } 517 518 devp->hd_irq = irq; 519 t = devp->hd_ireqfreq; 520 v = readq(&timer->hpet_config); 521 522 /* 64-bit comparators are not yet supported through the ioctls, 523 * so force this into 32-bit mode if it supports both modes 524 */ 525 g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; 526 527 if (devp->hd_flags & HPET_PERIODIC) { 528 g |= Tn_TYPE_CNF_MASK; 529 v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; 530 writeq(v, &timer->hpet_config); 531 local_irq_save(flags); 532 533 /* 534 * NOTE: First we modify the hidden accumulator 535 * register supported by periodic-capable comparators. 536 * We never want to modify the (single) counter; that 537 * would affect all the comparators. The value written 538 * is the counter value when the first interrupt is due. 539 */ 540 m = read_counter(&hpet->hpet_mc); 541 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 542 /* 543 * Then we modify the comparator, indicating the period 544 * for subsequent interrupt. 545 */ 546 write_counter(t, &timer->hpet_compare); 547 } else { 548 local_irq_save(flags); 549 m = read_counter(&hpet->hpet_mc); 550 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 551 } 552 553 if (devp->hd_flags & HPET_SHARED_IRQ) { 554 isr = 1 << (devp - devp->hd_hpets->hp_dev); 555 writel(isr, &hpet->hpet_isr); 556 } 557 writeq(g, &timer->hpet_config); 558 local_irq_restore(flags); 559 560 return 0; 561 } 562 563 /* converts Hz to number of timer ticks */ 564 static inline unsigned long hpet_time_div(struct hpets *hpets, 565 unsigned long dis) 566 { 567 unsigned long long m; 568 569 m = hpets->hp_tick_freq + (dis >> 1); 570 return div64_ul(m, dis); 571 } 572 573 static int 574 hpet_ioctl_common(struct hpet_dev *devp, unsigned int cmd, unsigned long arg, 575 struct hpet_info *info) 576 { 577 struct hpet_timer __iomem *timer; 578 struct hpets *hpetp; 579 int err; 580 unsigned long v; 581 582 switch (cmd) { 583 case HPET_IE_OFF: 584 case HPET_INFO: 585 case HPET_EPI: 586 case HPET_DPI: 587 case HPET_IRQFREQ: 588 timer = devp->hd_timer; 589 hpetp = devp->hd_hpets; 590 break; 591 case HPET_IE_ON: 592 return hpet_ioctl_ieon(devp); 593 default: 594 return -EINVAL; 595 } 596 597 err = 0; 598 599 switch (cmd) { 600 case HPET_IE_OFF: 601 if ((devp->hd_flags & HPET_IE) == 0) 602 break; 603 v = readq(&timer->hpet_config); 604 v &= ~Tn_INT_ENB_CNF_MASK; 605 writeq(v, &timer->hpet_config); 606 if (devp->hd_irq) { 607 free_irq(devp->hd_irq, devp); 608 devp->hd_irq = 0; 609 } 610 devp->hd_flags ^= HPET_IE; 611 break; 612 case HPET_INFO: 613 { 614 memset(info, 0, sizeof(*info)); 615 if (devp->hd_ireqfreq) 616 info->hi_ireqfreq = 617 hpet_time_div(hpetp, devp->hd_ireqfreq); 618 info->hi_flags = 619 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 620 info->hi_hpet = hpetp->hp_which; 621 info->hi_timer = devp - hpetp->hp_dev; 622 break; 623 } 624 case HPET_EPI: 625 v = readq(&timer->hpet_config); 626 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 627 err = -ENXIO; 628 break; 629 } 630 devp->hd_flags |= HPET_PERIODIC; 631 break; 632 case HPET_DPI: 633 v = readq(&timer->hpet_config); 634 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 635 err = -ENXIO; 636 break; 637 } 638 if (devp->hd_flags & HPET_PERIODIC && 639 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 640 v = readq(&timer->hpet_config); 641 v ^= Tn_TYPE_CNF_MASK; 642 writeq(v, &timer->hpet_config); 643 } 644 devp->hd_flags &= ~HPET_PERIODIC; 645 break; 646 case HPET_IRQFREQ: 647 if ((arg > hpet_max_freq) && 648 !capable(CAP_SYS_RESOURCE)) { 649 err = -EACCES; 650 break; 651 } 652 653 if (!arg) { 654 err = -EINVAL; 655 break; 656 } 657 658 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 659 } 660 661 return err; 662 } 663 664 static long 665 hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 666 { 667 struct hpet_info info; 668 int err; 669 670 mutex_lock(&hpet_mutex); 671 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 672 mutex_unlock(&hpet_mutex); 673 674 if ((cmd == HPET_INFO) && !err && 675 (copy_to_user((void __user *)arg, &info, sizeof(info)))) 676 err = -EFAULT; 677 678 return err; 679 } 680 681 #ifdef CONFIG_COMPAT 682 struct compat_hpet_info { 683 compat_ulong_t hi_ireqfreq; /* Hz */ 684 compat_ulong_t hi_flags; /* information */ 685 unsigned short hi_hpet; 686 unsigned short hi_timer; 687 }; 688 689 static long 690 hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 691 { 692 struct hpet_info info; 693 int err; 694 695 mutex_lock(&hpet_mutex); 696 err = hpet_ioctl_common(file->private_data, cmd, arg, &info); 697 mutex_unlock(&hpet_mutex); 698 699 if ((cmd == HPET_INFO) && !err) { 700 struct compat_hpet_info __user *u = compat_ptr(arg); 701 if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) || 702 put_user(info.hi_flags, &u->hi_flags) || 703 put_user(info.hi_hpet, &u->hi_hpet) || 704 put_user(info.hi_timer, &u->hi_timer)) 705 err = -EFAULT; 706 } 707 708 return err; 709 } 710 #endif 711 712 static const struct file_operations hpet_fops = { 713 .owner = THIS_MODULE, 714 .llseek = no_llseek, 715 .read = hpet_read, 716 .poll = hpet_poll, 717 .unlocked_ioctl = hpet_ioctl, 718 #ifdef CONFIG_COMPAT 719 .compat_ioctl = hpet_compat_ioctl, 720 #endif 721 .open = hpet_open, 722 .release = hpet_release, 723 .fasync = hpet_fasync, 724 .mmap = hpet_mmap, 725 }; 726 727 static int hpet_is_known(struct hpet_data *hdp) 728 { 729 struct hpets *hpetp; 730 731 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 732 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 733 return 1; 734 735 return 0; 736 } 737 738 static struct ctl_table hpet_table[] = { 739 { 740 .procname = "max-user-freq", 741 .data = &hpet_max_freq, 742 .maxlen = sizeof(int), 743 .mode = 0644, 744 .proc_handler = proc_dointvec, 745 }, 746 {} 747 }; 748 749 static struct ctl_table hpet_root[] = { 750 { 751 .procname = "hpet", 752 .maxlen = 0, 753 .mode = 0555, 754 .child = hpet_table, 755 }, 756 {} 757 }; 758 759 static struct ctl_table dev_root[] = { 760 { 761 .procname = "dev", 762 .maxlen = 0, 763 .mode = 0555, 764 .child = hpet_root, 765 }, 766 {} 767 }; 768 769 static struct ctl_table_header *sysctl_header; 770 771 /* 772 * Adjustment for when arming the timer with 773 * initial conditions. That is, main counter 774 * ticks expired before interrupts are enabled. 775 */ 776 #define TICK_CALIBRATE (1000UL) 777 778 static unsigned long __hpet_calibrate(struct hpets *hpetp) 779 { 780 struct hpet_timer __iomem *timer = NULL; 781 unsigned long t, m, count, i, flags, start; 782 struct hpet_dev *devp; 783 int j; 784 struct hpet __iomem *hpet; 785 786 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 787 if ((devp->hd_flags & HPET_OPEN) == 0) { 788 timer = devp->hd_timer; 789 break; 790 } 791 792 if (!timer) 793 return 0; 794 795 hpet = hpetp->hp_hpet; 796 t = read_counter(&timer->hpet_compare); 797 798 i = 0; 799 count = hpet_time_div(hpetp, TICK_CALIBRATE); 800 801 local_irq_save(flags); 802 803 start = read_counter(&hpet->hpet_mc); 804 805 do { 806 m = read_counter(&hpet->hpet_mc); 807 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 808 } while (i++, (m - start) < count); 809 810 local_irq_restore(flags); 811 812 return (m - start) / i; 813 } 814 815 static unsigned long hpet_calibrate(struct hpets *hpetp) 816 { 817 unsigned long ret = ~0UL; 818 unsigned long tmp; 819 820 /* 821 * Try to calibrate until return value becomes stable small value. 822 * If SMI interruption occurs in calibration loop, the return value 823 * will be big. This avoids its impact. 824 */ 825 for ( ; ; ) { 826 tmp = __hpet_calibrate(hpetp); 827 if (ret <= tmp) 828 break; 829 ret = tmp; 830 } 831 832 return ret; 833 } 834 835 int hpet_alloc(struct hpet_data *hdp) 836 { 837 u64 cap, mcfg; 838 struct hpet_dev *devp; 839 u32 i, ntimer; 840 struct hpets *hpetp; 841 struct hpet __iomem *hpet; 842 static struct hpets *last; 843 unsigned long period; 844 unsigned long long temp; 845 u32 remainder; 846 847 /* 848 * hpet_alloc can be called by platform dependent code. 849 * If platform dependent code has allocated the hpet that 850 * ACPI has also reported, then we catch it here. 851 */ 852 if (hpet_is_known(hdp)) { 853 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 854 __func__); 855 return 0; 856 } 857 858 hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs), 859 GFP_KERNEL); 860 861 if (!hpetp) 862 return -ENOMEM; 863 864 hpetp->hp_which = hpet_nhpet++; 865 hpetp->hp_hpet = hdp->hd_address; 866 hpetp->hp_hpet_phys = hdp->hd_phys_address; 867 868 hpetp->hp_ntimer = hdp->hd_nirqs; 869 870 for (i = 0; i < hdp->hd_nirqs; i++) 871 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 872 873 hpet = hpetp->hp_hpet; 874 875 cap = readq(&hpet->hpet_cap); 876 877 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 878 879 if (hpetp->hp_ntimer != ntimer) { 880 printk(KERN_WARNING "hpet: number irqs doesn't agree" 881 " with number of timers\n"); 882 kfree(hpetp); 883 return -ENODEV; 884 } 885 886 if (last) 887 last->hp_next = hpetp; 888 else 889 hpets = hpetp; 890 891 last = hpetp; 892 893 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 894 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 895 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 896 temp += period >> 1; /* round */ 897 do_div(temp, period); 898 hpetp->hp_tick_freq = temp; /* ticks per second */ 899 900 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 901 hpetp->hp_which, hdp->hd_phys_address, 902 hpetp->hp_ntimer > 1 ? "s" : ""); 903 for (i = 0; i < hpetp->hp_ntimer; i++) 904 printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 905 printk(KERN_CONT "\n"); 906 907 temp = hpetp->hp_tick_freq; 908 remainder = do_div(temp, 1000000); 909 printk(KERN_INFO 910 "hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n", 911 hpetp->hp_which, hpetp->hp_ntimer, 912 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, 913 (unsigned) temp, remainder); 914 915 mcfg = readq(&hpet->hpet_config); 916 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 917 write_counter(0L, &hpet->hpet_mc); 918 mcfg |= HPET_ENABLE_CNF_MASK; 919 writeq(mcfg, &hpet->hpet_config); 920 } 921 922 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 923 struct hpet_timer __iomem *timer; 924 925 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 926 927 devp->hd_hpets = hpetp; 928 devp->hd_hpet = hpet; 929 devp->hd_timer = timer; 930 931 /* 932 * If the timer was reserved by platform code, 933 * then make timer unavailable for opens. 934 */ 935 if (hdp->hd_state & (1 << i)) { 936 devp->hd_flags = HPET_OPEN; 937 continue; 938 } 939 940 init_waitqueue_head(&devp->hd_waitqueue); 941 } 942 943 hpetp->hp_delta = hpet_calibrate(hpetp); 944 945 /* This clocksource driver currently only works on ia64 */ 946 #ifdef CONFIG_IA64 947 if (!hpet_clocksource) { 948 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 949 clocksource_hpet.archdata.fsys_mmio = hpet_mctr; 950 clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); 951 hpetp->hp_clocksource = &clocksource_hpet; 952 hpet_clocksource = &clocksource_hpet; 953 } 954 #endif 955 956 return 0; 957 } 958 959 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 960 { 961 struct hpet_data *hdp; 962 acpi_status status; 963 struct acpi_resource_address64 addr; 964 965 hdp = data; 966 967 status = acpi_resource_to_address64(res, &addr); 968 969 if (ACPI_SUCCESS(status)) { 970 hdp->hd_phys_address = addr.address.minimum; 971 hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length); 972 if (!hdp->hd_address) 973 return AE_ERROR; 974 975 if (hpet_is_known(hdp)) { 976 iounmap(hdp->hd_address); 977 return AE_ALREADY_EXISTS; 978 } 979 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 980 struct acpi_resource_fixed_memory32 *fixmem32; 981 982 fixmem32 = &res->data.fixed_memory32; 983 984 hdp->hd_phys_address = fixmem32->address; 985 hdp->hd_address = ioremap(fixmem32->address, 986 HPET_RANGE_SIZE); 987 if (!hdp->hd_address) 988 return AE_ERROR; 989 990 if (hpet_is_known(hdp)) { 991 iounmap(hdp->hd_address); 992 return AE_ALREADY_EXISTS; 993 } 994 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 995 struct acpi_resource_extended_irq *irqp; 996 int i, irq; 997 998 irqp = &res->data.extended_irq; 999 1000 for (i = 0; i < irqp->interrupt_count; i++) { 1001 if (hdp->hd_nirqs >= HPET_MAX_TIMERS) 1002 break; 1003 1004 irq = acpi_register_gsi(NULL, irqp->interrupts[i], 1005 irqp->triggering, irqp->polarity); 1006 if (irq < 0) 1007 return AE_ERROR; 1008 1009 hdp->hd_irq[hdp->hd_nirqs] = irq; 1010 hdp->hd_nirqs++; 1011 } 1012 } 1013 1014 return AE_OK; 1015 } 1016 1017 static int hpet_acpi_add(struct acpi_device *device) 1018 { 1019 acpi_status result; 1020 struct hpet_data data; 1021 1022 memset(&data, 0, sizeof(data)); 1023 1024 result = 1025 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 1026 hpet_resources, &data); 1027 1028 if (ACPI_FAILURE(result)) 1029 return -ENODEV; 1030 1031 if (!data.hd_address || !data.hd_nirqs) { 1032 if (data.hd_address) 1033 iounmap(data.hd_address); 1034 printk("%s: no address or irqs in _CRS\n", __func__); 1035 return -ENODEV; 1036 } 1037 1038 return hpet_alloc(&data); 1039 } 1040 1041 static const struct acpi_device_id hpet_device_ids[] = { 1042 {"PNP0103", 0}, 1043 {"", 0}, 1044 }; 1045 1046 static struct acpi_driver hpet_acpi_driver = { 1047 .name = "hpet", 1048 .ids = hpet_device_ids, 1049 .ops = { 1050 .add = hpet_acpi_add, 1051 }, 1052 }; 1053 1054 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1055 1056 static int __init hpet_init(void) 1057 { 1058 int result; 1059 1060 result = misc_register(&hpet_misc); 1061 if (result < 0) 1062 return -ENODEV; 1063 1064 sysctl_header = register_sysctl_table(dev_root); 1065 1066 result = acpi_bus_register_driver(&hpet_acpi_driver); 1067 if (result < 0) { 1068 if (sysctl_header) 1069 unregister_sysctl_table(sysctl_header); 1070 misc_deregister(&hpet_misc); 1071 return result; 1072 } 1073 1074 return 0; 1075 } 1076 device_initcall(hpet_init); 1077 1078 /* 1079 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1080 MODULE_LICENSE("GPL"); 1081 */ 1082