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/clocksource.h> 33 34 #include <asm/current.h> 35 #include <asm/uaccess.h> 36 #include <asm/system.h> 37 #include <asm/io.h> 38 #include <asm/irq.h> 39 #include <asm/div64.h> 40 41 #include <linux/acpi.h> 42 #include <acpi/acpi_bus.h> 43 #include <linux/hpet.h> 44 45 /* 46 * The High Precision Event Timer driver. 47 * This driver is closely modelled after the rtc.c driver. 48 * http://www.intel.com/hardwaredesign/hpetspec.htm 49 */ 50 #define HPET_USER_FREQ (64) 51 #define HPET_DRIFT (500) 52 53 #define HPET_RANGE_SIZE 1024 /* from HPET spec */ 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 u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 64 65 /* This clocksource driver currently only works on ia64 */ 66 #ifdef CONFIG_IA64 67 static void __iomem *hpet_mctr; 68 69 static cycle_t read_hpet(void) 70 { 71 return (cycle_t)read_counter((void __iomem *)hpet_mctr); 72 } 73 74 static struct clocksource clocksource_hpet = { 75 .name = "hpet", 76 .rating = 250, 77 .read = read_hpet, 78 .mask = CLOCKSOURCE_MASK(64), 79 .mult = 0, /*to be caluclated*/ 80 .shift = 10, 81 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 82 }; 83 static struct clocksource *hpet_clocksource; 84 #endif 85 86 /* A lock for concurrent access by app and isr hpet activity. */ 87 static DEFINE_SPINLOCK(hpet_lock); 88 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */ 89 static DEFINE_SPINLOCK(hpet_task_lock); 90 91 #define HPET_DEV_NAME (7) 92 93 struct hpet_dev { 94 struct hpets *hd_hpets; 95 struct hpet __iomem *hd_hpet; 96 struct hpet_timer __iomem *hd_timer; 97 unsigned long hd_ireqfreq; 98 unsigned long hd_irqdata; 99 wait_queue_head_t hd_waitqueue; 100 struct fasync_struct *hd_async_queue; 101 struct hpet_task *hd_task; 102 unsigned int hd_flags; 103 unsigned int hd_irq; 104 unsigned int hd_hdwirq; 105 char hd_name[HPET_DEV_NAME]; 106 }; 107 108 struct hpets { 109 struct hpets *hp_next; 110 struct hpet __iomem *hp_hpet; 111 unsigned long hp_hpet_phys; 112 struct clocksource *hp_clocksource; 113 unsigned long long hp_tick_freq; 114 unsigned long hp_delta; 115 unsigned int hp_ntimer; 116 unsigned int hp_which; 117 struct hpet_dev hp_dev[1]; 118 }; 119 120 static struct hpets *hpets; 121 122 #define HPET_OPEN 0x0001 123 #define HPET_IE 0x0002 /* interrupt enabled */ 124 #define HPET_PERIODIC 0x0004 125 #define HPET_SHARED_IRQ 0x0008 126 127 128 #ifndef readq 129 static inline unsigned long long readq(void __iomem *addr) 130 { 131 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 132 } 133 #endif 134 135 #ifndef writeq 136 static inline void writeq(unsigned long long v, void __iomem *addr) 137 { 138 writel(v & 0xffffffff, addr); 139 writel(v >> 32, addr + 4); 140 } 141 #endif 142 143 static irqreturn_t hpet_interrupt(int irq, void *data) 144 { 145 struct hpet_dev *devp; 146 unsigned long isr; 147 148 devp = data; 149 isr = 1 << (devp - devp->hd_hpets->hp_dev); 150 151 if ((devp->hd_flags & HPET_SHARED_IRQ) && 152 !(isr & readl(&devp->hd_hpet->hpet_isr))) 153 return IRQ_NONE; 154 155 spin_lock(&hpet_lock); 156 devp->hd_irqdata++; 157 158 /* 159 * For non-periodic timers, increment the accumulator. 160 * This has the effect of treating non-periodic like periodic. 161 */ 162 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 163 unsigned long m, t; 164 165 t = devp->hd_ireqfreq; 166 m = read_counter(&devp->hd_hpet->hpet_mc); 167 write_counter(t + m + devp->hd_hpets->hp_delta, 168 &devp->hd_timer->hpet_compare); 169 } 170 171 if (devp->hd_flags & HPET_SHARED_IRQ) 172 writel(isr, &devp->hd_hpet->hpet_isr); 173 spin_unlock(&hpet_lock); 174 175 spin_lock(&hpet_task_lock); 176 if (devp->hd_task) 177 devp->hd_task->ht_func(devp->hd_task->ht_data); 178 spin_unlock(&hpet_task_lock); 179 180 wake_up_interruptible(&devp->hd_waitqueue); 181 182 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 183 184 return IRQ_HANDLED; 185 } 186 187 static int hpet_open(struct inode *inode, struct file *file) 188 { 189 struct hpet_dev *devp; 190 struct hpets *hpetp; 191 int i; 192 193 if (file->f_mode & FMODE_WRITE) 194 return -EINVAL; 195 196 spin_lock_irq(&hpet_lock); 197 198 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 199 for (i = 0; i < hpetp->hp_ntimer; i++) 200 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN 201 || hpetp->hp_dev[i].hd_task) 202 continue; 203 else { 204 devp = &hpetp->hp_dev[i]; 205 break; 206 } 207 208 if (!devp) { 209 spin_unlock_irq(&hpet_lock); 210 return -EBUSY; 211 } 212 213 file->private_data = devp; 214 devp->hd_irqdata = 0; 215 devp->hd_flags |= HPET_OPEN; 216 spin_unlock_irq(&hpet_lock); 217 218 return 0; 219 } 220 221 static ssize_t 222 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 223 { 224 DECLARE_WAITQUEUE(wait, current); 225 unsigned long data; 226 ssize_t retval; 227 struct hpet_dev *devp; 228 229 devp = file->private_data; 230 if (!devp->hd_ireqfreq) 231 return -EIO; 232 233 if (count < sizeof(unsigned long)) 234 return -EINVAL; 235 236 add_wait_queue(&devp->hd_waitqueue, &wait); 237 238 for ( ; ; ) { 239 set_current_state(TASK_INTERRUPTIBLE); 240 241 spin_lock_irq(&hpet_lock); 242 data = devp->hd_irqdata; 243 devp->hd_irqdata = 0; 244 spin_unlock_irq(&hpet_lock); 245 246 if (data) 247 break; 248 else if (file->f_flags & O_NONBLOCK) { 249 retval = -EAGAIN; 250 goto out; 251 } else if (signal_pending(current)) { 252 retval = -ERESTARTSYS; 253 goto out; 254 } 255 schedule(); 256 } 257 258 retval = put_user(data, (unsigned long __user *)buf); 259 if (!retval) 260 retval = sizeof(unsigned long); 261 out: 262 __set_current_state(TASK_RUNNING); 263 remove_wait_queue(&devp->hd_waitqueue, &wait); 264 265 return retval; 266 } 267 268 static unsigned int hpet_poll(struct file *file, poll_table * wait) 269 { 270 unsigned long v; 271 struct hpet_dev *devp; 272 273 devp = file->private_data; 274 275 if (!devp->hd_ireqfreq) 276 return 0; 277 278 poll_wait(file, &devp->hd_waitqueue, wait); 279 280 spin_lock_irq(&hpet_lock); 281 v = devp->hd_irqdata; 282 spin_unlock_irq(&hpet_lock); 283 284 if (v != 0) 285 return POLLIN | POLLRDNORM; 286 287 return 0; 288 } 289 290 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 291 { 292 #ifdef CONFIG_HPET_MMAP 293 struct hpet_dev *devp; 294 unsigned long addr; 295 296 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 297 return -EINVAL; 298 299 devp = file->private_data; 300 addr = devp->hd_hpets->hp_hpet_phys; 301 302 if (addr & (PAGE_SIZE - 1)) 303 return -ENOSYS; 304 305 vma->vm_flags |= VM_IO; 306 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 307 308 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 309 PAGE_SIZE, vma->vm_page_prot)) { 310 printk(KERN_ERR "%s: io_remap_pfn_range failed\n", 311 __FUNCTION__); 312 return -EAGAIN; 313 } 314 315 return 0; 316 #else 317 return -ENOSYS; 318 #endif 319 } 320 321 static int hpet_fasync(int fd, struct file *file, int on) 322 { 323 struct hpet_dev *devp; 324 325 devp = file->private_data; 326 327 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 328 return 0; 329 else 330 return -EIO; 331 } 332 333 static int hpet_release(struct inode *inode, struct file *file) 334 { 335 struct hpet_dev *devp; 336 struct hpet_timer __iomem *timer; 337 int irq = 0; 338 339 devp = file->private_data; 340 timer = devp->hd_timer; 341 342 spin_lock_irq(&hpet_lock); 343 344 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 345 &timer->hpet_config); 346 347 irq = devp->hd_irq; 348 devp->hd_irq = 0; 349 350 devp->hd_ireqfreq = 0; 351 352 if (devp->hd_flags & HPET_PERIODIC 353 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 354 unsigned long v; 355 356 v = readq(&timer->hpet_config); 357 v ^= Tn_TYPE_CNF_MASK; 358 writeq(v, &timer->hpet_config); 359 } 360 361 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 362 spin_unlock_irq(&hpet_lock); 363 364 if (irq) 365 free_irq(irq, devp); 366 367 if (file->f_flags & FASYNC) 368 hpet_fasync(-1, file, 0); 369 370 file->private_data = NULL; 371 return 0; 372 } 373 374 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 375 376 static int 377 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 378 unsigned long arg) 379 { 380 struct hpet_dev *devp; 381 382 devp = file->private_data; 383 return hpet_ioctl_common(devp, cmd, arg, 0); 384 } 385 386 static int hpet_ioctl_ieon(struct hpet_dev *devp) 387 { 388 struct hpet_timer __iomem *timer; 389 struct hpet __iomem *hpet; 390 struct hpets *hpetp; 391 int irq; 392 unsigned long g, v, t, m; 393 unsigned long flags, isr; 394 395 timer = devp->hd_timer; 396 hpet = devp->hd_hpet; 397 hpetp = devp->hd_hpets; 398 399 if (!devp->hd_ireqfreq) 400 return -EIO; 401 402 spin_lock_irq(&hpet_lock); 403 404 if (devp->hd_flags & HPET_IE) { 405 spin_unlock_irq(&hpet_lock); 406 return -EBUSY; 407 } 408 409 devp->hd_flags |= HPET_IE; 410 411 if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK) 412 devp->hd_flags |= HPET_SHARED_IRQ; 413 spin_unlock_irq(&hpet_lock); 414 415 irq = devp->hd_hdwirq; 416 417 if (irq) { 418 unsigned long irq_flags; 419 420 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 421 irq_flags = devp->hd_flags & HPET_SHARED_IRQ 422 ? IRQF_SHARED : IRQF_DISABLED; 423 if (request_irq(irq, hpet_interrupt, irq_flags, 424 devp->hd_name, (void *)devp)) { 425 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 426 irq = 0; 427 } 428 } 429 430 if (irq == 0) { 431 spin_lock_irq(&hpet_lock); 432 devp->hd_flags ^= HPET_IE; 433 spin_unlock_irq(&hpet_lock); 434 return -EIO; 435 } 436 437 devp->hd_irq = irq; 438 t = devp->hd_ireqfreq; 439 v = readq(&timer->hpet_config); 440 g = v | Tn_INT_ENB_CNF_MASK; 441 442 if (devp->hd_flags & HPET_PERIODIC) { 443 write_counter(t, &timer->hpet_compare); 444 g |= Tn_TYPE_CNF_MASK; 445 v |= Tn_TYPE_CNF_MASK; 446 writeq(v, &timer->hpet_config); 447 v |= Tn_VAL_SET_CNF_MASK; 448 writeq(v, &timer->hpet_config); 449 local_irq_save(flags); 450 m = read_counter(&hpet->hpet_mc); 451 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 452 } else { 453 local_irq_save(flags); 454 m = read_counter(&hpet->hpet_mc); 455 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 456 } 457 458 if (devp->hd_flags & HPET_SHARED_IRQ) { 459 isr = 1 << (devp - devp->hd_hpets->hp_dev); 460 writel(isr, &hpet->hpet_isr); 461 } 462 writeq(g, &timer->hpet_config); 463 local_irq_restore(flags); 464 465 return 0; 466 } 467 468 /* converts Hz to number of timer ticks */ 469 static inline unsigned long hpet_time_div(struct hpets *hpets, 470 unsigned long dis) 471 { 472 unsigned long long m; 473 474 m = hpets->hp_tick_freq + (dis >> 1); 475 do_div(m, dis); 476 return (unsigned long)m; 477 } 478 479 static int 480 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 481 { 482 struct hpet_timer __iomem *timer; 483 struct hpet __iomem *hpet; 484 struct hpets *hpetp; 485 int err; 486 unsigned long v; 487 488 switch (cmd) { 489 case HPET_IE_OFF: 490 case HPET_INFO: 491 case HPET_EPI: 492 case HPET_DPI: 493 case HPET_IRQFREQ: 494 timer = devp->hd_timer; 495 hpet = devp->hd_hpet; 496 hpetp = devp->hd_hpets; 497 break; 498 case HPET_IE_ON: 499 return hpet_ioctl_ieon(devp); 500 default: 501 return -EINVAL; 502 } 503 504 err = 0; 505 506 switch (cmd) { 507 case HPET_IE_OFF: 508 if ((devp->hd_flags & HPET_IE) == 0) 509 break; 510 v = readq(&timer->hpet_config); 511 v &= ~Tn_INT_ENB_CNF_MASK; 512 writeq(v, &timer->hpet_config); 513 if (devp->hd_irq) { 514 free_irq(devp->hd_irq, devp); 515 devp->hd_irq = 0; 516 } 517 devp->hd_flags ^= HPET_IE; 518 break; 519 case HPET_INFO: 520 { 521 struct hpet_info info; 522 523 if (devp->hd_ireqfreq) 524 info.hi_ireqfreq = 525 hpet_time_div(hpetp, devp->hd_ireqfreq); 526 else 527 info.hi_ireqfreq = 0; 528 info.hi_flags = 529 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 530 info.hi_hpet = hpetp->hp_which; 531 info.hi_timer = devp - hpetp->hp_dev; 532 if (kernel) 533 memcpy((void *)arg, &info, sizeof(info)); 534 else 535 if (copy_to_user((void __user *)arg, &info, 536 sizeof(info))) 537 err = -EFAULT; 538 break; 539 } 540 case HPET_EPI: 541 v = readq(&timer->hpet_config); 542 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 543 err = -ENXIO; 544 break; 545 } 546 devp->hd_flags |= HPET_PERIODIC; 547 break; 548 case HPET_DPI: 549 v = readq(&timer->hpet_config); 550 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 551 err = -ENXIO; 552 break; 553 } 554 if (devp->hd_flags & HPET_PERIODIC && 555 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 556 v = readq(&timer->hpet_config); 557 v ^= Tn_TYPE_CNF_MASK; 558 writeq(v, &timer->hpet_config); 559 } 560 devp->hd_flags &= ~HPET_PERIODIC; 561 break; 562 case HPET_IRQFREQ: 563 if (!kernel && (arg > hpet_max_freq) && 564 !capable(CAP_SYS_RESOURCE)) { 565 err = -EACCES; 566 break; 567 } 568 569 if (!arg) { 570 err = -EINVAL; 571 break; 572 } 573 574 devp->hd_ireqfreq = hpet_time_div(hpetp, arg); 575 } 576 577 return err; 578 } 579 580 static const struct file_operations hpet_fops = { 581 .owner = THIS_MODULE, 582 .llseek = no_llseek, 583 .read = hpet_read, 584 .poll = hpet_poll, 585 .ioctl = hpet_ioctl, 586 .open = hpet_open, 587 .release = hpet_release, 588 .fasync = hpet_fasync, 589 .mmap = hpet_mmap, 590 }; 591 592 static int hpet_is_known(struct hpet_data *hdp) 593 { 594 struct hpets *hpetp; 595 596 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 597 if (hpetp->hp_hpet_phys == hdp->hd_phys_address) 598 return 1; 599 600 return 0; 601 } 602 603 EXPORT_SYMBOL(hpet_alloc); 604 EXPORT_SYMBOL(hpet_register); 605 EXPORT_SYMBOL(hpet_unregister); 606 EXPORT_SYMBOL(hpet_control); 607 608 int hpet_register(struct hpet_task *tp, int periodic) 609 { 610 unsigned int i; 611 u64 mask; 612 struct hpet_timer __iomem *timer; 613 struct hpet_dev *devp; 614 struct hpets *hpetp; 615 616 switch (periodic) { 617 case 1: 618 mask = Tn_PER_INT_CAP_MASK; 619 break; 620 case 0: 621 mask = 0; 622 break; 623 default: 624 return -EINVAL; 625 } 626 627 tp->ht_opaque = NULL; 628 629 spin_lock_irq(&hpet_task_lock); 630 spin_lock(&hpet_lock); 631 632 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 633 for (timer = hpetp->hp_hpet->hpet_timers, i = 0; 634 i < hpetp->hp_ntimer; i++, timer++) { 635 if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK) 636 != mask) 637 continue; 638 639 devp = &hpetp->hp_dev[i]; 640 641 if (devp->hd_flags & HPET_OPEN || devp->hd_task) { 642 devp = NULL; 643 continue; 644 } 645 646 tp->ht_opaque = devp; 647 devp->hd_task = tp; 648 break; 649 } 650 651 spin_unlock(&hpet_lock); 652 spin_unlock_irq(&hpet_task_lock); 653 654 if (tp->ht_opaque) 655 return 0; 656 else 657 return -EBUSY; 658 } 659 660 static inline int hpet_tpcheck(struct hpet_task *tp) 661 { 662 struct hpet_dev *devp; 663 struct hpets *hpetp; 664 665 devp = tp->ht_opaque; 666 667 if (!devp) 668 return -ENXIO; 669 670 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 671 if (devp >= hpetp->hp_dev 672 && devp < (hpetp->hp_dev + hpetp->hp_ntimer) 673 && devp->hd_hpet == hpetp->hp_hpet) 674 return 0; 675 676 return -ENXIO; 677 } 678 679 int hpet_unregister(struct hpet_task *tp) 680 { 681 struct hpet_dev *devp; 682 struct hpet_timer __iomem *timer; 683 int err; 684 685 if ((err = hpet_tpcheck(tp))) 686 return err; 687 688 spin_lock_irq(&hpet_task_lock); 689 spin_lock(&hpet_lock); 690 691 devp = tp->ht_opaque; 692 if (devp->hd_task != tp) { 693 spin_unlock(&hpet_lock); 694 spin_unlock_irq(&hpet_task_lock); 695 return -ENXIO; 696 } 697 698 timer = devp->hd_timer; 699 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 700 &timer->hpet_config); 701 devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC); 702 devp->hd_task = NULL; 703 spin_unlock(&hpet_lock); 704 spin_unlock_irq(&hpet_task_lock); 705 706 return 0; 707 } 708 709 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg) 710 { 711 struct hpet_dev *devp; 712 int err; 713 714 if ((err = hpet_tpcheck(tp))) 715 return err; 716 717 spin_lock_irq(&hpet_lock); 718 devp = tp->ht_opaque; 719 if (devp->hd_task != tp) { 720 spin_unlock_irq(&hpet_lock); 721 return -ENXIO; 722 } 723 spin_unlock_irq(&hpet_lock); 724 return hpet_ioctl_common(devp, cmd, arg, 1); 725 } 726 727 static ctl_table hpet_table[] = { 728 { 729 .ctl_name = CTL_UNNUMBERED, 730 .procname = "max-user-freq", 731 .data = &hpet_max_freq, 732 .maxlen = sizeof(int), 733 .mode = 0644, 734 .proc_handler = &proc_dointvec, 735 }, 736 {.ctl_name = 0} 737 }; 738 739 static ctl_table hpet_root[] = { 740 { 741 .ctl_name = CTL_UNNUMBERED, 742 .procname = "hpet", 743 .maxlen = 0, 744 .mode = 0555, 745 .child = hpet_table, 746 }, 747 {.ctl_name = 0} 748 }; 749 750 static ctl_table dev_root[] = { 751 { 752 .ctl_name = CTL_DEV, 753 .procname = "dev", 754 .maxlen = 0, 755 .mode = 0555, 756 .child = hpet_root, 757 }, 758 {.ctl_name = 0} 759 }; 760 761 static struct ctl_table_header *sysctl_header; 762 763 /* 764 * Adjustment for when arming the timer with 765 * initial conditions. That is, main counter 766 * ticks expired before interrupts are enabled. 767 */ 768 #define TICK_CALIBRATE (1000UL) 769 770 static unsigned long hpet_calibrate(struct hpets *hpetp) 771 { 772 struct hpet_timer __iomem *timer = NULL; 773 unsigned long t, m, count, i, flags, start; 774 struct hpet_dev *devp; 775 int j; 776 struct hpet __iomem *hpet; 777 778 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 779 if ((devp->hd_flags & HPET_OPEN) == 0) { 780 timer = devp->hd_timer; 781 break; 782 } 783 784 if (!timer) 785 return 0; 786 787 hpet = hpetp->hp_hpet; 788 t = read_counter(&timer->hpet_compare); 789 790 i = 0; 791 count = hpet_time_div(hpetp, TICK_CALIBRATE); 792 793 local_irq_save(flags); 794 795 start = read_counter(&hpet->hpet_mc); 796 797 do { 798 m = read_counter(&hpet->hpet_mc); 799 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 800 } while (i++, (m - start) < count); 801 802 local_irq_restore(flags); 803 804 return (m - start) / i; 805 } 806 807 int hpet_alloc(struct hpet_data *hdp) 808 { 809 u64 cap, mcfg; 810 struct hpet_dev *devp; 811 u32 i, ntimer; 812 struct hpets *hpetp; 813 size_t siz; 814 struct hpet __iomem *hpet; 815 static struct hpets *last = NULL; 816 unsigned long period; 817 unsigned long long temp; 818 819 /* 820 * hpet_alloc can be called by platform dependent code. 821 * If platform dependent code has allocated the hpet that 822 * ACPI has also reported, then we catch it here. 823 */ 824 if (hpet_is_known(hdp)) { 825 printk(KERN_DEBUG "%s: duplicate HPET ignored\n", 826 __FUNCTION__); 827 return 0; 828 } 829 830 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 831 sizeof(struct hpet_dev)); 832 833 hpetp = kzalloc(siz, GFP_KERNEL); 834 835 if (!hpetp) 836 return -ENOMEM; 837 838 hpetp->hp_which = hpet_nhpet++; 839 hpetp->hp_hpet = hdp->hd_address; 840 hpetp->hp_hpet_phys = hdp->hd_phys_address; 841 842 hpetp->hp_ntimer = hdp->hd_nirqs; 843 844 for (i = 0; i < hdp->hd_nirqs; i++) 845 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 846 847 hpet = hpetp->hp_hpet; 848 849 cap = readq(&hpet->hpet_cap); 850 851 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 852 853 if (hpetp->hp_ntimer != ntimer) { 854 printk(KERN_WARNING "hpet: number irqs doesn't agree" 855 " with number of timers\n"); 856 kfree(hpetp); 857 return -ENODEV; 858 } 859 860 if (last) 861 last->hp_next = hpetp; 862 else 863 hpets = hpetp; 864 865 last = hpetp; 866 867 period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 868 HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */ 869 temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */ 870 temp += period >> 1; /* round */ 871 do_div(temp, period); 872 hpetp->hp_tick_freq = temp; /* ticks per second */ 873 874 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 875 hpetp->hp_which, hdp->hd_phys_address, 876 hpetp->hp_ntimer > 1 ? "s" : ""); 877 for (i = 0; i < hpetp->hp_ntimer; i++) 878 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 879 printk("\n"); 880 881 printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n", 882 hpetp->hp_which, hpetp->hp_ntimer, 883 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq); 884 885 mcfg = readq(&hpet->hpet_config); 886 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 887 write_counter(0L, &hpet->hpet_mc); 888 mcfg |= HPET_ENABLE_CNF_MASK; 889 writeq(mcfg, &hpet->hpet_config); 890 } 891 892 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) { 893 struct hpet_timer __iomem *timer; 894 895 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 896 897 devp->hd_hpets = hpetp; 898 devp->hd_hpet = hpet; 899 devp->hd_timer = timer; 900 901 /* 902 * If the timer was reserved by platform code, 903 * then make timer unavailable for opens. 904 */ 905 if (hdp->hd_state & (1 << i)) { 906 devp->hd_flags = HPET_OPEN; 907 continue; 908 } 909 910 init_waitqueue_head(&devp->hd_waitqueue); 911 } 912 913 hpetp->hp_delta = hpet_calibrate(hpetp); 914 915 /* This clocksource driver currently only works on ia64 */ 916 #ifdef CONFIG_IA64 917 if (!hpet_clocksource) { 918 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; 919 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); 920 clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, 921 clocksource_hpet.shift); 922 clocksource_register(&clocksource_hpet); 923 hpetp->hp_clocksource = &clocksource_hpet; 924 hpet_clocksource = &clocksource_hpet; 925 } 926 #endif 927 928 return 0; 929 } 930 931 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 932 { 933 struct hpet_data *hdp; 934 acpi_status status; 935 struct acpi_resource_address64 addr; 936 937 hdp = data; 938 939 status = acpi_resource_to_address64(res, &addr); 940 941 if (ACPI_SUCCESS(status)) { 942 hdp->hd_phys_address = addr.minimum; 943 hdp->hd_address = ioremap(addr.minimum, addr.address_length); 944 945 if (hpet_is_known(hdp)) { 946 printk(KERN_DEBUG "%s: 0x%lx is busy\n", 947 __FUNCTION__, hdp->hd_phys_address); 948 iounmap(hdp->hd_address); 949 return AE_ALREADY_EXISTS; 950 } 951 } else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) { 952 struct acpi_resource_fixed_memory32 *fixmem32; 953 954 fixmem32 = &res->data.fixed_memory32; 955 if (!fixmem32) 956 return AE_NO_MEMORY; 957 958 hdp->hd_phys_address = fixmem32->address; 959 hdp->hd_address = ioremap(fixmem32->address, 960 HPET_RANGE_SIZE); 961 962 if (hpet_is_known(hdp)) { 963 printk(KERN_DEBUG "%s: 0x%lx is busy\n", 964 __FUNCTION__, hdp->hd_phys_address); 965 iounmap(hdp->hd_address); 966 return AE_ALREADY_EXISTS; 967 } 968 } else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) { 969 struct acpi_resource_extended_irq *irqp; 970 int i, irq; 971 972 irqp = &res->data.extended_irq; 973 974 for (i = 0; i < irqp->interrupt_count; i++) { 975 irq = acpi_register_gsi(irqp->interrupts[i], 976 irqp->triggering, irqp->polarity); 977 if (irq < 0) 978 return AE_ERROR; 979 980 hdp->hd_irq[hdp->hd_nirqs] = irq; 981 hdp->hd_nirqs++; 982 } 983 } 984 985 return AE_OK; 986 } 987 988 static int hpet_acpi_add(struct acpi_device *device) 989 { 990 acpi_status result; 991 struct hpet_data data; 992 993 memset(&data, 0, sizeof(data)); 994 995 result = 996 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 997 hpet_resources, &data); 998 999 if (ACPI_FAILURE(result)) 1000 return -ENODEV; 1001 1002 if (!data.hd_address || !data.hd_nirqs) { 1003 printk("%s: no address or irqs in _CRS\n", __FUNCTION__); 1004 return -ENODEV; 1005 } 1006 1007 return hpet_alloc(&data); 1008 } 1009 1010 static int hpet_acpi_remove(struct acpi_device *device, int type) 1011 { 1012 /* XXX need to unregister clocksource, dealloc mem, etc */ 1013 return -EINVAL; 1014 } 1015 1016 static const struct acpi_device_id hpet_device_ids[] = { 1017 {"PNP0103", 0}, 1018 {"", 0}, 1019 }; 1020 MODULE_DEVICE_TABLE(acpi, hpet_device_ids); 1021 1022 static struct acpi_driver hpet_acpi_driver = { 1023 .name = "hpet", 1024 .ids = hpet_device_ids, 1025 .ops = { 1026 .add = hpet_acpi_add, 1027 .remove = hpet_acpi_remove, 1028 }, 1029 }; 1030 1031 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 1032 1033 static int __init hpet_init(void) 1034 { 1035 int result; 1036 1037 result = misc_register(&hpet_misc); 1038 if (result < 0) 1039 return -ENODEV; 1040 1041 sysctl_header = register_sysctl_table(dev_root); 1042 1043 result = acpi_bus_register_driver(&hpet_acpi_driver); 1044 if (result < 0) { 1045 if (sysctl_header) 1046 unregister_sysctl_table(sysctl_header); 1047 misc_deregister(&hpet_misc); 1048 return result; 1049 } 1050 1051 return 0; 1052 } 1053 1054 static void __exit hpet_exit(void) 1055 { 1056 acpi_bus_unregister_driver(&hpet_acpi_driver); 1057 1058 if (sysctl_header) 1059 unregister_sysctl_table(sysctl_header); 1060 misc_deregister(&hpet_misc); 1061 1062 return; 1063 } 1064 1065 module_init(hpet_init); 1066 module_exit(hpet_exit); 1067 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 1068 MODULE_LICENSE("GPL"); 1069