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/config.h> 15 #include <linux/interrupt.h> 16 #include <linux/module.h> 17 #include <linux/kernel.h> 18 #include <linux/types.h> 19 #include <linux/miscdevice.h> 20 #include <linux/major.h> 21 #include <linux/ioport.h> 22 #include <linux/fcntl.h> 23 #include <linux/init.h> 24 #include <linux/poll.h> 25 #include <linux/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 33 #include <asm/current.h> 34 #include <asm/uaccess.h> 35 #include <asm/system.h> 36 #include <asm/io.h> 37 #include <asm/irq.h> 38 #include <asm/div64.h> 39 40 #include <linux/acpi.h> 41 #include <acpi/acpi_bus.h> 42 #include <linux/hpet.h> 43 44 /* 45 * The High Precision Event Timer driver. 46 * This driver is closely modelled after the rtc.c driver. 47 * http://www.intel.com/labs/platcomp/hpet/hpetspec.htm 48 */ 49 #define HPET_USER_FREQ (64) 50 #define HPET_DRIFT (500) 51 52 static u32 hpet_ntimer, hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; 53 54 /* A lock for concurrent access by app and isr hpet activity. */ 55 static DEFINE_SPINLOCK(hpet_lock); 56 /* A lock for concurrent intermodule access to hpet and isr hpet activity. */ 57 static DEFINE_SPINLOCK(hpet_task_lock); 58 59 #define HPET_DEV_NAME (7) 60 61 struct hpet_dev { 62 struct hpets *hd_hpets; 63 struct hpet __iomem *hd_hpet; 64 struct hpet_timer __iomem *hd_timer; 65 unsigned long hd_ireqfreq; 66 unsigned long hd_irqdata; 67 wait_queue_head_t hd_waitqueue; 68 struct fasync_struct *hd_async_queue; 69 struct hpet_task *hd_task; 70 unsigned int hd_flags; 71 unsigned int hd_irq; 72 unsigned int hd_hdwirq; 73 char hd_name[HPET_DEV_NAME]; 74 }; 75 76 struct hpets { 77 struct hpets *hp_next; 78 struct hpet __iomem *hp_hpet; 79 unsigned long hp_hpet_phys; 80 struct time_interpolator *hp_interpolator; 81 unsigned long hp_period; 82 unsigned long hp_delta; 83 unsigned int hp_ntimer; 84 unsigned int hp_which; 85 struct hpet_dev hp_dev[1]; 86 }; 87 88 static struct hpets *hpets; 89 90 #define HPET_OPEN 0x0001 91 #define HPET_IE 0x0002 /* interrupt enabled */ 92 #define HPET_PERIODIC 0x0004 93 94 #if BITS_PER_LONG == 64 95 #define write_counter(V, MC) writeq(V, MC) 96 #define read_counter(MC) readq(MC) 97 #else 98 #define write_counter(V, MC) writel(V, MC) 99 #define read_counter(MC) readl(MC) 100 #endif 101 102 #ifndef readq 103 static unsigned long long __inline readq(void __iomem *addr) 104 { 105 return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); 106 } 107 #endif 108 109 #ifndef writeq 110 static void __inline writeq(unsigned long long v, void __iomem *addr) 111 { 112 writel(v & 0xffffffff, addr); 113 writel(v >> 32, addr + 4); 114 } 115 #endif 116 117 static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs) 118 { 119 struct hpet_dev *devp; 120 unsigned long isr; 121 122 devp = data; 123 124 spin_lock(&hpet_lock); 125 devp->hd_irqdata++; 126 127 /* 128 * For non-periodic timers, increment the accumulator. 129 * This has the effect of treating non-periodic like periodic. 130 */ 131 if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { 132 unsigned long m, t; 133 134 t = devp->hd_ireqfreq; 135 m = read_counter(&devp->hd_hpet->hpet_mc); 136 write_counter(t + m + devp->hd_hpets->hp_delta, 137 &devp->hd_timer->hpet_compare); 138 } 139 140 isr = (1 << (devp - devp->hd_hpets->hp_dev)); 141 writeq(isr, &devp->hd_hpet->hpet_isr); 142 spin_unlock(&hpet_lock); 143 144 spin_lock(&hpet_task_lock); 145 if (devp->hd_task) 146 devp->hd_task->ht_func(devp->hd_task->ht_data); 147 spin_unlock(&hpet_task_lock); 148 149 wake_up_interruptible(&devp->hd_waitqueue); 150 151 kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN); 152 153 return IRQ_HANDLED; 154 } 155 156 static int hpet_open(struct inode *inode, struct file *file) 157 { 158 struct hpet_dev *devp; 159 struct hpets *hpetp; 160 int i; 161 162 if (file->f_mode & FMODE_WRITE) 163 return -EINVAL; 164 165 spin_lock_irq(&hpet_lock); 166 167 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 168 for (i = 0; i < hpetp->hp_ntimer; i++) 169 if (hpetp->hp_dev[i].hd_flags & HPET_OPEN 170 || hpetp->hp_dev[i].hd_task) 171 continue; 172 else { 173 devp = &hpetp->hp_dev[i]; 174 break; 175 } 176 177 if (!devp) { 178 spin_unlock_irq(&hpet_lock); 179 return -EBUSY; 180 } 181 182 file->private_data = devp; 183 devp->hd_irqdata = 0; 184 devp->hd_flags |= HPET_OPEN; 185 spin_unlock_irq(&hpet_lock); 186 187 return 0; 188 } 189 190 static ssize_t 191 hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) 192 { 193 DECLARE_WAITQUEUE(wait, current); 194 unsigned long data; 195 ssize_t retval; 196 struct hpet_dev *devp; 197 198 devp = file->private_data; 199 if (!devp->hd_ireqfreq) 200 return -EIO; 201 202 if (count < sizeof(unsigned long)) 203 return -EINVAL; 204 205 add_wait_queue(&devp->hd_waitqueue, &wait); 206 207 for ( ; ; ) { 208 set_current_state(TASK_INTERRUPTIBLE); 209 210 spin_lock_irq(&hpet_lock); 211 data = devp->hd_irqdata; 212 devp->hd_irqdata = 0; 213 spin_unlock_irq(&hpet_lock); 214 215 if (data) 216 break; 217 else if (file->f_flags & O_NONBLOCK) { 218 retval = -EAGAIN; 219 goto out; 220 } else if (signal_pending(current)) { 221 retval = -ERESTARTSYS; 222 goto out; 223 } 224 schedule(); 225 } 226 227 retval = put_user(data, (unsigned long __user *)buf); 228 if (!retval) 229 retval = sizeof(unsigned long); 230 out: 231 __set_current_state(TASK_RUNNING); 232 remove_wait_queue(&devp->hd_waitqueue, &wait); 233 234 return retval; 235 } 236 237 static unsigned int hpet_poll(struct file *file, poll_table * wait) 238 { 239 unsigned long v; 240 struct hpet_dev *devp; 241 242 devp = file->private_data; 243 244 if (!devp->hd_ireqfreq) 245 return 0; 246 247 poll_wait(file, &devp->hd_waitqueue, wait); 248 249 spin_lock_irq(&hpet_lock); 250 v = devp->hd_irqdata; 251 spin_unlock_irq(&hpet_lock); 252 253 if (v != 0) 254 return POLLIN | POLLRDNORM; 255 256 return 0; 257 } 258 259 static int hpet_mmap(struct file *file, struct vm_area_struct *vma) 260 { 261 #ifdef CONFIG_HPET_MMAP 262 struct hpet_dev *devp; 263 unsigned long addr; 264 265 if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) 266 return -EINVAL; 267 268 devp = file->private_data; 269 addr = devp->hd_hpets->hp_hpet_phys; 270 271 if (addr & (PAGE_SIZE - 1)) 272 return -ENOSYS; 273 274 vma->vm_flags |= VM_IO; 275 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 276 addr = __pa(addr); 277 278 if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, 279 PAGE_SIZE, vma->vm_page_prot)) { 280 printk(KERN_ERR "remap_pfn_range failed in hpet.c\n"); 281 return -EAGAIN; 282 } 283 284 return 0; 285 #else 286 return -ENOSYS; 287 #endif 288 } 289 290 static int hpet_fasync(int fd, struct file *file, int on) 291 { 292 struct hpet_dev *devp; 293 294 devp = file->private_data; 295 296 if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0) 297 return 0; 298 else 299 return -EIO; 300 } 301 302 static int hpet_release(struct inode *inode, struct file *file) 303 { 304 struct hpet_dev *devp; 305 struct hpet_timer __iomem *timer; 306 int irq = 0; 307 308 devp = file->private_data; 309 timer = devp->hd_timer; 310 311 spin_lock_irq(&hpet_lock); 312 313 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 314 &timer->hpet_config); 315 316 irq = devp->hd_irq; 317 devp->hd_irq = 0; 318 319 devp->hd_ireqfreq = 0; 320 321 if (devp->hd_flags & HPET_PERIODIC 322 && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 323 unsigned long v; 324 325 v = readq(&timer->hpet_config); 326 v ^= Tn_TYPE_CNF_MASK; 327 writeq(v, &timer->hpet_config); 328 } 329 330 devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC); 331 spin_unlock_irq(&hpet_lock); 332 333 if (irq) 334 free_irq(irq, devp); 335 336 if (file->f_flags & FASYNC) 337 hpet_fasync(-1, file, 0); 338 339 file->private_data = NULL; 340 return 0; 341 } 342 343 static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); 344 345 static int 346 hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 347 unsigned long arg) 348 { 349 struct hpet_dev *devp; 350 351 devp = file->private_data; 352 return hpet_ioctl_common(devp, cmd, arg, 0); 353 } 354 355 static int hpet_ioctl_ieon(struct hpet_dev *devp) 356 { 357 struct hpet_timer __iomem *timer; 358 struct hpet __iomem *hpet; 359 struct hpets *hpetp; 360 int irq; 361 unsigned long g, v, t, m; 362 unsigned long flags, isr; 363 364 timer = devp->hd_timer; 365 hpet = devp->hd_hpet; 366 hpetp = devp->hd_hpets; 367 368 v = readq(&timer->hpet_config); 369 spin_lock_irq(&hpet_lock); 370 371 if (devp->hd_flags & HPET_IE) { 372 spin_unlock_irq(&hpet_lock); 373 return -EBUSY; 374 } 375 376 devp->hd_flags |= HPET_IE; 377 spin_unlock_irq(&hpet_lock); 378 379 t = readq(&timer->hpet_config); 380 irq = devp->hd_hdwirq; 381 382 if (irq) { 383 sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); 384 385 if (request_irq 386 (irq, hpet_interrupt, SA_INTERRUPT, devp->hd_name, (void *)devp)) { 387 printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); 388 irq = 0; 389 } 390 } 391 392 if (irq == 0) { 393 spin_lock_irq(&hpet_lock); 394 devp->hd_flags ^= HPET_IE; 395 spin_unlock_irq(&hpet_lock); 396 return -EIO; 397 } 398 399 devp->hd_irq = irq; 400 t = devp->hd_ireqfreq; 401 v = readq(&timer->hpet_config); 402 g = v | Tn_INT_ENB_CNF_MASK; 403 404 if (devp->hd_flags & HPET_PERIODIC) { 405 write_counter(t, &timer->hpet_compare); 406 g |= Tn_TYPE_CNF_MASK; 407 v |= Tn_TYPE_CNF_MASK; 408 writeq(v, &timer->hpet_config); 409 v |= Tn_VAL_SET_CNF_MASK; 410 writeq(v, &timer->hpet_config); 411 local_irq_save(flags); 412 m = read_counter(&hpet->hpet_mc); 413 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 414 } else { 415 local_irq_save(flags); 416 m = read_counter(&hpet->hpet_mc); 417 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 418 } 419 420 isr = (1 << (devp - hpets->hp_dev)); 421 writeq(isr, &hpet->hpet_isr); 422 writeq(g, &timer->hpet_config); 423 local_irq_restore(flags); 424 425 return 0; 426 } 427 428 static inline unsigned long hpet_time_div(unsigned long dis) 429 { 430 unsigned long long m = 1000000000000000ULL; 431 432 do_div(m, dis); 433 434 return (unsigned long)m; 435 } 436 437 static int 438 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 439 { 440 struct hpet_timer __iomem *timer; 441 struct hpet __iomem *hpet; 442 struct hpets *hpetp; 443 int err; 444 unsigned long v; 445 446 switch (cmd) { 447 case HPET_IE_OFF: 448 case HPET_INFO: 449 case HPET_EPI: 450 case HPET_DPI: 451 case HPET_IRQFREQ: 452 timer = devp->hd_timer; 453 hpet = devp->hd_hpet; 454 hpetp = devp->hd_hpets; 455 break; 456 case HPET_IE_ON: 457 return hpet_ioctl_ieon(devp); 458 default: 459 return -EINVAL; 460 } 461 462 err = 0; 463 464 switch (cmd) { 465 case HPET_IE_OFF: 466 if ((devp->hd_flags & HPET_IE) == 0) 467 break; 468 v = readq(&timer->hpet_config); 469 v &= ~Tn_INT_ENB_CNF_MASK; 470 writeq(v, &timer->hpet_config); 471 if (devp->hd_irq) { 472 free_irq(devp->hd_irq, devp); 473 devp->hd_irq = 0; 474 } 475 devp->hd_flags ^= HPET_IE; 476 break; 477 case HPET_INFO: 478 { 479 struct hpet_info info; 480 481 info.hi_ireqfreq = hpet_time_div(hpetp->hp_period * 482 devp->hd_ireqfreq); 483 info.hi_flags = 484 readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; 485 info.hi_hpet = devp->hd_hpets->hp_which; 486 info.hi_timer = devp - devp->hd_hpets->hp_dev; 487 if (copy_to_user((void __user *)arg, &info, sizeof(info))) 488 err = -EFAULT; 489 break; 490 } 491 case HPET_EPI: 492 v = readq(&timer->hpet_config); 493 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 494 err = -ENXIO; 495 break; 496 } 497 devp->hd_flags |= HPET_PERIODIC; 498 break; 499 case HPET_DPI: 500 v = readq(&timer->hpet_config); 501 if ((v & Tn_PER_INT_CAP_MASK) == 0) { 502 err = -ENXIO; 503 break; 504 } 505 if (devp->hd_flags & HPET_PERIODIC && 506 readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) { 507 v = readq(&timer->hpet_config); 508 v ^= Tn_TYPE_CNF_MASK; 509 writeq(v, &timer->hpet_config); 510 } 511 devp->hd_flags &= ~HPET_PERIODIC; 512 break; 513 case HPET_IRQFREQ: 514 if (!kernel && (arg > hpet_max_freq) && 515 !capable(CAP_SYS_RESOURCE)) { 516 err = -EACCES; 517 break; 518 } 519 520 if (arg & (arg - 1)) { 521 err = -EINVAL; 522 break; 523 } 524 525 devp->hd_ireqfreq = hpet_time_div(hpetp->hp_period * arg); 526 } 527 528 return err; 529 } 530 531 static struct file_operations hpet_fops = { 532 .owner = THIS_MODULE, 533 .llseek = no_llseek, 534 .read = hpet_read, 535 .poll = hpet_poll, 536 .ioctl = hpet_ioctl, 537 .open = hpet_open, 538 .release = hpet_release, 539 .fasync = hpet_fasync, 540 .mmap = hpet_mmap, 541 }; 542 543 EXPORT_SYMBOL(hpet_alloc); 544 EXPORT_SYMBOL(hpet_register); 545 EXPORT_SYMBOL(hpet_unregister); 546 EXPORT_SYMBOL(hpet_control); 547 548 int hpet_register(struct hpet_task *tp, int periodic) 549 { 550 unsigned int i; 551 u64 mask; 552 struct hpet_timer __iomem *timer; 553 struct hpet_dev *devp; 554 struct hpets *hpetp; 555 556 switch (periodic) { 557 case 1: 558 mask = Tn_PER_INT_CAP_MASK; 559 break; 560 case 0: 561 mask = 0; 562 break; 563 default: 564 return -EINVAL; 565 } 566 567 spin_lock_irq(&hpet_task_lock); 568 spin_lock(&hpet_lock); 569 570 for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) 571 for (timer = hpetp->hp_hpet->hpet_timers, i = 0; 572 i < hpetp->hp_ntimer; i++, timer++) { 573 if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK) 574 != mask) 575 continue; 576 577 devp = &hpetp->hp_dev[i]; 578 579 if (devp->hd_flags & HPET_OPEN || devp->hd_task) { 580 devp = NULL; 581 continue; 582 } 583 584 tp->ht_opaque = devp; 585 devp->hd_task = tp; 586 break; 587 } 588 589 spin_unlock(&hpet_lock); 590 spin_unlock_irq(&hpet_task_lock); 591 592 if (tp->ht_opaque) 593 return 0; 594 else 595 return -EBUSY; 596 } 597 598 static inline int hpet_tpcheck(struct hpet_task *tp) 599 { 600 struct hpet_dev *devp; 601 struct hpets *hpetp; 602 603 devp = tp->ht_opaque; 604 605 if (!devp) 606 return -ENXIO; 607 608 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 609 if (devp >= hpetp->hp_dev 610 && devp < (hpetp->hp_dev + hpetp->hp_ntimer) 611 && devp->hd_hpet == hpetp->hp_hpet) 612 return 0; 613 614 return -ENXIO; 615 } 616 617 int hpet_unregister(struct hpet_task *tp) 618 { 619 struct hpet_dev *devp; 620 struct hpet_timer __iomem *timer; 621 int err; 622 623 if ((err = hpet_tpcheck(tp))) 624 return err; 625 626 spin_lock_irq(&hpet_task_lock); 627 spin_lock(&hpet_lock); 628 629 devp = tp->ht_opaque; 630 if (devp->hd_task != tp) { 631 spin_unlock(&hpet_lock); 632 spin_unlock_irq(&hpet_task_lock); 633 return -ENXIO; 634 } 635 636 timer = devp->hd_timer; 637 writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK), 638 &timer->hpet_config); 639 devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC); 640 devp->hd_task = NULL; 641 spin_unlock(&hpet_lock); 642 spin_unlock_irq(&hpet_task_lock); 643 644 return 0; 645 } 646 647 int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg) 648 { 649 struct hpet_dev *devp; 650 int err; 651 652 if ((err = hpet_tpcheck(tp))) 653 return err; 654 655 spin_lock_irq(&hpet_lock); 656 devp = tp->ht_opaque; 657 if (devp->hd_task != tp) { 658 spin_unlock_irq(&hpet_lock); 659 return -ENXIO; 660 } 661 spin_unlock_irq(&hpet_lock); 662 return hpet_ioctl_common(devp, cmd, arg, 1); 663 } 664 665 static ctl_table hpet_table[] = { 666 { 667 .ctl_name = 1, 668 .procname = "max-user-freq", 669 .data = &hpet_max_freq, 670 .maxlen = sizeof(int), 671 .mode = 0644, 672 .proc_handler = &proc_dointvec, 673 }, 674 {.ctl_name = 0} 675 }; 676 677 static ctl_table hpet_root[] = { 678 { 679 .ctl_name = 1, 680 .procname = "hpet", 681 .maxlen = 0, 682 .mode = 0555, 683 .child = hpet_table, 684 }, 685 {.ctl_name = 0} 686 }; 687 688 static ctl_table dev_root[] = { 689 { 690 .ctl_name = CTL_DEV, 691 .procname = "dev", 692 .maxlen = 0, 693 .mode = 0555, 694 .child = hpet_root, 695 }, 696 {.ctl_name = 0} 697 }; 698 699 static struct ctl_table_header *sysctl_header; 700 701 static void hpet_register_interpolator(struct hpets *hpetp) 702 { 703 #ifdef CONFIG_TIME_INTERPOLATION 704 struct time_interpolator *ti; 705 706 ti = kmalloc(sizeof(*ti), GFP_KERNEL); 707 if (!ti) 708 return; 709 710 memset(ti, 0, sizeof(*ti)); 711 ti->source = TIME_SOURCE_MMIO64; 712 ti->shift = 10; 713 ti->addr = &hpetp->hp_hpet->hpet_mc; 714 ti->frequency = hpet_time_div(hpets->hp_period); 715 ti->drift = ti->frequency * HPET_DRIFT / 1000000; 716 ti->mask = -1; 717 718 hpetp->hp_interpolator = ti; 719 register_time_interpolator(ti); 720 #endif 721 } 722 723 /* 724 * Adjustment for when arming the timer with 725 * initial conditions. That is, main counter 726 * ticks expired before interrupts are enabled. 727 */ 728 #define TICK_CALIBRATE (1000UL) 729 730 static unsigned long hpet_calibrate(struct hpets *hpetp) 731 { 732 struct hpet_timer __iomem *timer = NULL; 733 unsigned long t, m, count, i, flags, start; 734 struct hpet_dev *devp; 735 int j; 736 struct hpet __iomem *hpet; 737 738 for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++) 739 if ((devp->hd_flags & HPET_OPEN) == 0) { 740 timer = devp->hd_timer; 741 break; 742 } 743 744 if (!timer) 745 return 0; 746 747 hpet = hpets->hp_hpet; 748 t = read_counter(&timer->hpet_compare); 749 750 i = 0; 751 count = hpet_time_div(hpetp->hp_period * TICK_CALIBRATE); 752 753 local_irq_save(flags); 754 755 start = read_counter(&hpet->hpet_mc); 756 757 do { 758 m = read_counter(&hpet->hpet_mc); 759 write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); 760 } while (i++, (m - start) < count); 761 762 local_irq_restore(flags); 763 764 return (m - start) / i; 765 } 766 767 int hpet_alloc(struct hpet_data *hdp) 768 { 769 u64 cap, mcfg; 770 struct hpet_dev *devp; 771 u32 i, ntimer; 772 struct hpets *hpetp; 773 size_t siz; 774 struct hpet __iomem *hpet; 775 static struct hpets *last = (struct hpets *)0; 776 unsigned long ns; 777 778 /* 779 * hpet_alloc can be called by platform dependent code. 780 * if platform dependent code has allocated the hpet 781 * ACPI also reports hpet, then we catch it here. 782 */ 783 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 784 if (hpetp->hp_hpet == hdp->hd_address) 785 return 0; 786 787 siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) * 788 sizeof(struct hpet_dev)); 789 790 hpetp = kmalloc(siz, GFP_KERNEL); 791 792 if (!hpetp) 793 return -ENOMEM; 794 795 memset(hpetp, 0, siz); 796 797 hpetp->hp_which = hpet_nhpet++; 798 hpetp->hp_hpet = hdp->hd_address; 799 hpetp->hp_hpet_phys = hdp->hd_phys_address; 800 801 hpetp->hp_ntimer = hdp->hd_nirqs; 802 803 for (i = 0; i < hdp->hd_nirqs; i++) 804 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; 805 806 hpet = hpetp->hp_hpet; 807 808 cap = readq(&hpet->hpet_cap); 809 810 ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1; 811 812 if (hpetp->hp_ntimer != ntimer) { 813 printk(KERN_WARNING "hpet: number irqs doesn't agree" 814 " with number of timers\n"); 815 kfree(hpetp); 816 return -ENODEV; 817 } 818 819 if (last) 820 last->hp_next = hpetp; 821 else 822 hpets = hpetp; 823 824 last = hpetp; 825 826 hpetp->hp_period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >> 827 HPET_COUNTER_CLK_PERIOD_SHIFT; 828 829 printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s", 830 hpetp->hp_which, hdp->hd_phys_address, 831 hpetp->hp_ntimer > 1 ? "s" : ""); 832 for (i = 0; i < hpetp->hp_ntimer; i++) 833 printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); 834 printk("\n"); 835 836 ns = hpetp->hp_period; /* femptoseconds, 10^-15 */ 837 do_div(ns, 1000000); /* convert to nanoseconds, 10^-9 */ 838 printk(KERN_INFO "hpet%d: %ldns tick, %d %d-bit timers\n", 839 hpetp->hp_which, ns, hpetp->hp_ntimer, 840 cap & HPET_COUNTER_SIZE_MASK ? 64 : 32); 841 842 mcfg = readq(&hpet->hpet_config); 843 if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) { 844 write_counter(0L, &hpet->hpet_mc); 845 mcfg |= HPET_ENABLE_CNF_MASK; 846 writeq(mcfg, &hpet->hpet_config); 847 } 848 849 for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; 850 i++, hpet_ntimer++, devp++) { 851 unsigned long v; 852 struct hpet_timer __iomem *timer; 853 854 timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; 855 v = readq(&timer->hpet_config); 856 857 devp->hd_hpets = hpetp; 858 devp->hd_hpet = hpet; 859 devp->hd_timer = timer; 860 861 /* 862 * If the timer was reserved by platform code, 863 * then make timer unavailable for opens. 864 */ 865 if (hdp->hd_state & (1 << i)) { 866 devp->hd_flags = HPET_OPEN; 867 continue; 868 } 869 870 init_waitqueue_head(&devp->hd_waitqueue); 871 } 872 873 hpetp->hp_delta = hpet_calibrate(hpetp); 874 hpet_register_interpolator(hpetp); 875 876 return 0; 877 } 878 879 static acpi_status hpet_resources(struct acpi_resource *res, void *data) 880 { 881 struct hpet_data *hdp; 882 acpi_status status; 883 struct acpi_resource_address64 addr; 884 struct hpets *hpetp; 885 886 hdp = data; 887 888 status = acpi_resource_to_address64(res, &addr); 889 890 if (ACPI_SUCCESS(status)) { 891 unsigned long size; 892 893 size = addr.max_address_range - addr.min_address_range + 1; 894 hdp->hd_phys_address = addr.min_address_range; 895 hdp->hd_address = ioremap(addr.min_address_range, size); 896 897 for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next) 898 if (hpetp->hp_hpet == hdp->hd_address) 899 return -EBUSY; 900 } else if (res->id == ACPI_RSTYPE_EXT_IRQ) { 901 struct acpi_resource_ext_irq *irqp; 902 int i; 903 904 irqp = &res->data.extended_irq; 905 906 if (irqp->number_of_interrupts > 0) { 907 hdp->hd_nirqs = irqp->number_of_interrupts; 908 909 for (i = 0; i < hdp->hd_nirqs; i++) 910 hdp->hd_irq[i] = 911 acpi_register_gsi(irqp->interrupts[i], 912 irqp->edge_level, 913 irqp->active_high_low); 914 } 915 } 916 917 return AE_OK; 918 } 919 920 static int hpet_acpi_add(struct acpi_device *device) 921 { 922 acpi_status result; 923 struct hpet_data data; 924 925 memset(&data, 0, sizeof(data)); 926 927 result = 928 acpi_walk_resources(device->handle, METHOD_NAME__CRS, 929 hpet_resources, &data); 930 931 if (ACPI_FAILURE(result)) 932 return -ENODEV; 933 934 if (!data.hd_address || !data.hd_nirqs) { 935 printk("%s: no address or irqs in _CRS\n", __FUNCTION__); 936 return -ENODEV; 937 } 938 939 return hpet_alloc(&data); 940 } 941 942 static int hpet_acpi_remove(struct acpi_device *device, int type) 943 { 944 /* XXX need to unregister interpolator, dealloc mem, etc */ 945 return -EINVAL; 946 } 947 948 static struct acpi_driver hpet_acpi_driver = { 949 .name = "hpet", 950 .ids = "PNP0103", 951 .ops = { 952 .add = hpet_acpi_add, 953 .remove = hpet_acpi_remove, 954 }, 955 }; 956 957 static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops }; 958 959 static int __init hpet_init(void) 960 { 961 int result; 962 963 result = misc_register(&hpet_misc); 964 if (result < 0) 965 return -ENODEV; 966 967 sysctl_header = register_sysctl_table(dev_root, 0); 968 969 result = acpi_bus_register_driver(&hpet_acpi_driver); 970 if (result < 0) { 971 if (sysctl_header) 972 unregister_sysctl_table(sysctl_header); 973 misc_deregister(&hpet_misc); 974 return result; 975 } 976 977 return 0; 978 } 979 980 static void __exit hpet_exit(void) 981 { 982 acpi_bus_unregister_driver(&hpet_acpi_driver); 983 984 if (sysctl_header) 985 unregister_sysctl_table(sysctl_header); 986 misc_deregister(&hpet_misc); 987 988 return; 989 } 990 991 module_init(hpet_init); 992 module_exit(hpet_exit); 993 MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>"); 994 MODULE_LICENSE("GPL"); 995