hpet.c 22.1 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
/*
 * Intel & MS High Precision Event Timer Implementation.
 *
 * Copyright (C) 2003 Intel Corporation
 *	Venki Pallipadi
 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
 *	Bob Picco <robert.picco@hp.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/major.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/sysctl.h>
#include <linux/wait.h>
#include <linux/bcd.h>
#include <linux/seq_file.h>
#include <linux/bitops.h>

#include <asm/current.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/div64.h>

#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <linux/hpet.h>

/*
 * The High Precision Event Timer driver.
 * This driver is closely modelled after the rtc.c driver.
46
 * http://www.intel.com/hardwaredesign/hpetspec.htm
L
Linus Torvalds 已提交
47 48 49 50
 */
#define	HPET_USER_FREQ	(64)
#define	HPET_DRIFT	(500)

51 52
#define HPET_RANGE_SIZE		1024	/* from HPET spec */

53
static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
L
Linus Torvalds 已提交
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81

/* A lock for concurrent access by app and isr hpet activity. */
static DEFINE_SPINLOCK(hpet_lock);
/* A lock for concurrent intermodule access to hpet and isr hpet activity. */
static DEFINE_SPINLOCK(hpet_task_lock);

#define	HPET_DEV_NAME	(7)

struct hpet_dev {
	struct hpets *hd_hpets;
	struct hpet __iomem *hd_hpet;
	struct hpet_timer __iomem *hd_timer;
	unsigned long hd_ireqfreq;
	unsigned long hd_irqdata;
	wait_queue_head_t hd_waitqueue;
	struct fasync_struct *hd_async_queue;
	struct hpet_task *hd_task;
	unsigned int hd_flags;
	unsigned int hd_irq;
	unsigned int hd_hdwirq;
	char hd_name[HPET_DEV_NAME];
};

struct hpets {
	struct hpets *hp_next;
	struct hpet __iomem *hp_hpet;
	unsigned long hp_hpet_phys;
	struct time_interpolator *hp_interpolator;
82
	unsigned long long hp_tick_freq;
L
Linus Torvalds 已提交
83 84 85 86 87 88 89 90 91 92 93
	unsigned long hp_delta;
	unsigned int hp_ntimer;
	unsigned int hp_which;
	struct hpet_dev hp_dev[1];
};

static struct hpets *hpets;

#define	HPET_OPEN		0x0001
#define	HPET_IE			0x0002	/* interrupt enabled */
#define	HPET_PERIODIC		0x0004
94
#define	HPET_SHARED_IRQ		0x0008
L
Linus Torvalds 已提交
95 96 97 98 99 100 101 102 103 104

#if BITS_PER_LONG == 64
#define	write_counter(V, MC)	writeq(V, MC)
#define	read_counter(MC)	readq(MC)
#else
#define	write_counter(V, MC) 	writel(V, MC)
#define	read_counter(MC)	readl(MC)
#endif

#ifndef readq
105
static inline unsigned long long readq(void __iomem *addr)
L
Linus Torvalds 已提交
106 107 108 109 110 111
{
	return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
}
#endif

#ifndef writeq
112
static inline void writeq(unsigned long long v, void __iomem *addr)
L
Linus Torvalds 已提交
113 114 115 116 117 118 119 120 121 122 123 124
{
	writel(v & 0xffffffff, addr);
	writel(v >> 32, addr + 4);
}
#endif

static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs)
{
	struct hpet_dev *devp;
	unsigned long isr;

	devp = data;
125 126 127 128 129
	isr = 1 << (devp - devp->hd_hpets->hp_dev);

	if ((devp->hd_flags & HPET_SHARED_IRQ) &&
	    !(isr & readl(&devp->hd_hpet->hpet_isr)))
		return IRQ_NONE;
L
Linus Torvalds 已提交
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146

	spin_lock(&hpet_lock);
	devp->hd_irqdata++;

	/*
	 * For non-periodic timers, increment the accumulator.
	 * This has the effect of treating non-periodic like periodic.
	 */
	if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) {
		unsigned long m, t;

		t = devp->hd_ireqfreq;
		m = read_counter(&devp->hd_hpet->hpet_mc);
		write_counter(t + m + devp->hd_hpets->hp_delta,
			      &devp->hd_timer->hpet_compare);
	}

147 148
	if (devp->hd_flags & HPET_SHARED_IRQ)
		writel(isr, &devp->hd_hpet->hpet_isr);
L
Linus Torvalds 已提交
149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285
	spin_unlock(&hpet_lock);

	spin_lock(&hpet_task_lock);
	if (devp->hd_task)
		devp->hd_task->ht_func(devp->hd_task->ht_data);
	spin_unlock(&hpet_task_lock);

	wake_up_interruptible(&devp->hd_waitqueue);

	kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);

	return IRQ_HANDLED;
}

static int hpet_open(struct inode *inode, struct file *file)
{
	struct hpet_dev *devp;
	struct hpets *hpetp;
	int i;

	if (file->f_mode & FMODE_WRITE)
		return -EINVAL;

	spin_lock_irq(&hpet_lock);

	for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
		for (i = 0; i < hpetp->hp_ntimer; i++)
			if (hpetp->hp_dev[i].hd_flags & HPET_OPEN
			    || hpetp->hp_dev[i].hd_task)
				continue;
			else {
				devp = &hpetp->hp_dev[i];
				break;
			}

	if (!devp) {
		spin_unlock_irq(&hpet_lock);
		return -EBUSY;
	}

	file->private_data = devp;
	devp->hd_irqdata = 0;
	devp->hd_flags |= HPET_OPEN;
	spin_unlock_irq(&hpet_lock);

	return 0;
}

static ssize_t
hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long data;
	ssize_t retval;
	struct hpet_dev *devp;

	devp = file->private_data;
	if (!devp->hd_ireqfreq)
		return -EIO;

	if (count < sizeof(unsigned long))
		return -EINVAL;

	add_wait_queue(&devp->hd_waitqueue, &wait);

	for ( ; ; ) {
		set_current_state(TASK_INTERRUPTIBLE);

		spin_lock_irq(&hpet_lock);
		data = devp->hd_irqdata;
		devp->hd_irqdata = 0;
		spin_unlock_irq(&hpet_lock);

		if (data)
			break;
		else if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			goto out;
		} else if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			goto out;
		}
		schedule();
	}

	retval = put_user(data, (unsigned long __user *)buf);
	if (!retval)
		retval = sizeof(unsigned long);
out:
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&devp->hd_waitqueue, &wait);

	return retval;
}

static unsigned int hpet_poll(struct file *file, poll_table * wait)
{
	unsigned long v;
	struct hpet_dev *devp;

	devp = file->private_data;

	if (!devp->hd_ireqfreq)
		return 0;

	poll_wait(file, &devp->hd_waitqueue, wait);

	spin_lock_irq(&hpet_lock);
	v = devp->hd_irqdata;
	spin_unlock_irq(&hpet_lock);

	if (v != 0)
		return POLLIN | POLLRDNORM;

	return 0;
}

static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
{
#ifdef	CONFIG_HPET_MMAP
	struct hpet_dev *devp;
	unsigned long addr;

	if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
		return -EINVAL;

	devp = file->private_data;
	addr = devp->hd_hpets->hp_hpet_phys;

	if (addr & (PAGE_SIZE - 1))
		return -ENOSYS;

	vma->vm_flags |= VM_IO;
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
					PAGE_SIZE, vma->vm_page_prot)) {
R
Randy Dunlap 已提交
286 287
		printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
			__FUNCTION__);
L
Linus Torvalds 已提交
288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374
		return -EAGAIN;
	}

	return 0;
#else
	return -ENOSYS;
#endif
}

static int hpet_fasync(int fd, struct file *file, int on)
{
	struct hpet_dev *devp;

	devp = file->private_data;

	if (fasync_helper(fd, file, on, &devp->hd_async_queue) >= 0)
		return 0;
	else
		return -EIO;
}

static int hpet_release(struct inode *inode, struct file *file)
{
	struct hpet_dev *devp;
	struct hpet_timer __iomem *timer;
	int irq = 0;

	devp = file->private_data;
	timer = devp->hd_timer;

	spin_lock_irq(&hpet_lock);

	writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
	       &timer->hpet_config);

	irq = devp->hd_irq;
	devp->hd_irq = 0;

	devp->hd_ireqfreq = 0;

	if (devp->hd_flags & HPET_PERIODIC
	    && readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
		unsigned long v;

		v = readq(&timer->hpet_config);
		v ^= Tn_TYPE_CNF_MASK;
		writeq(v, &timer->hpet_config);
	}

	devp->hd_flags &= ~(HPET_OPEN | HPET_IE | HPET_PERIODIC);
	spin_unlock_irq(&hpet_lock);

	if (irq)
		free_irq(irq, devp);

	if (file->f_flags & FASYNC)
		hpet_fasync(-1, file, 0);

	file->private_data = NULL;
	return 0;
}

static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);

static int
hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	   unsigned long arg)
{
	struct hpet_dev *devp;

	devp = file->private_data;
	return hpet_ioctl_common(devp, cmd, arg, 0);
}

static int hpet_ioctl_ieon(struct hpet_dev *devp)
{
	struct hpet_timer __iomem *timer;
	struct hpet __iomem *hpet;
	struct hpets *hpetp;
	int irq;
	unsigned long g, v, t, m;
	unsigned long flags, isr;

	timer = devp->hd_timer;
	hpet = devp->hd_hpet;
	hpetp = devp->hd_hpets;

375 376 377
	if (!devp->hd_ireqfreq)
		return -EIO;

L
Linus Torvalds 已提交
378 379 380 381 382 383 384 385
	spin_lock_irq(&hpet_lock);

	if (devp->hd_flags & HPET_IE) {
		spin_unlock_irq(&hpet_lock);
		return -EBUSY;
	}

	devp->hd_flags |= HPET_IE;
386 387 388

	if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
		devp->hd_flags |= HPET_SHARED_IRQ;
L
Linus Torvalds 已提交
389 390 391 392 393
	spin_unlock_irq(&hpet_lock);

	irq = devp->hd_hdwirq;

	if (irq) {
394
		unsigned long irq_flags;
L
Linus Torvalds 已提交
395

396 397
		sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
		irq_flags = devp->hd_flags & HPET_SHARED_IRQ
398
						? IRQF_SHARED : IRQF_DISABLED;
399 400
		if (request_irq(irq, hpet_interrupt, irq_flags,
				devp->hd_name, (void *)devp)) {
L
Linus Torvalds 已提交
401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433
			printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);
			irq = 0;
		}
	}

	if (irq == 0) {
		spin_lock_irq(&hpet_lock);
		devp->hd_flags ^= HPET_IE;
		spin_unlock_irq(&hpet_lock);
		return -EIO;
	}

	devp->hd_irq = irq;
	t = devp->hd_ireqfreq;
	v = readq(&timer->hpet_config);
	g = v | Tn_INT_ENB_CNF_MASK;

	if (devp->hd_flags & HPET_PERIODIC) {
		write_counter(t, &timer->hpet_compare);
		g |= Tn_TYPE_CNF_MASK;
		v |= Tn_TYPE_CNF_MASK;
		writeq(v, &timer->hpet_config);
		v |= Tn_VAL_SET_CNF_MASK;
		writeq(v, &timer->hpet_config);
		local_irq_save(flags);
		m = read_counter(&hpet->hpet_mc);
		write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
	} else {
		local_irq_save(flags);
		m = read_counter(&hpet->hpet_mc);
		write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
	}

434
	if (devp->hd_flags & HPET_SHARED_IRQ) {
435
		isr = 1 << (devp - devp->hd_hpets->hp_dev);
436 437
		writel(isr, &hpet->hpet_isr);
	}
L
Linus Torvalds 已提交
438 439 440 441 442 443
	writeq(g, &timer->hpet_config);
	local_irq_restore(flags);

	return 0;
}

444 445 446
/* converts Hz to number of timer ticks */
static inline unsigned long hpet_time_div(struct hpets *hpets,
					  unsigned long dis)
L
Linus Torvalds 已提交
447
{
448
	unsigned long long m;
L
Linus Torvalds 已提交
449

450
	m = hpets->hp_tick_freq + (dis >> 1);
L
Linus Torvalds 已提交
451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498
	do_div(m, dis);
	return (unsigned long)m;
}

static int
hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
{
	struct hpet_timer __iomem *timer;
	struct hpet __iomem *hpet;
	struct hpets *hpetp;
	int err;
	unsigned long v;

	switch (cmd) {
	case HPET_IE_OFF:
	case HPET_INFO:
	case HPET_EPI:
	case HPET_DPI:
	case HPET_IRQFREQ:
		timer = devp->hd_timer;
		hpet = devp->hd_hpet;
		hpetp = devp->hd_hpets;
		break;
	case HPET_IE_ON:
		return hpet_ioctl_ieon(devp);
	default:
		return -EINVAL;
	}

	err = 0;

	switch (cmd) {
	case HPET_IE_OFF:
		if ((devp->hd_flags & HPET_IE) == 0)
			break;
		v = readq(&timer->hpet_config);
		v &= ~Tn_INT_ENB_CNF_MASK;
		writeq(v, &timer->hpet_config);
		if (devp->hd_irq) {
			free_irq(devp->hd_irq, devp);
			devp->hd_irq = 0;
		}
		devp->hd_flags ^= HPET_IE;
		break;
	case HPET_INFO:
		{
			struct hpet_info info;

499 500 501 502 503
			if (devp->hd_ireqfreq)
				info.hi_ireqfreq =
					hpet_time_div(hpetp, devp->hd_ireqfreq);
			else
				info.hi_ireqfreq = 0;
L
Linus Torvalds 已提交
504 505
			info.hi_flags =
			    readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
506 507
			info.hi_hpet = hpetp->hp_which;
			info.hi_timer = devp - hpetp->hp_dev;
508 509 510 511 512 513
			if (kernel)
				memcpy((void *)arg, &info, sizeof(info));
			else
				if (copy_to_user((void __user *)arg, &info,
						 sizeof(info)))
					err = -EFAULT;
L
Linus Torvalds 已提交
514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544
			break;
		}
	case HPET_EPI:
		v = readq(&timer->hpet_config);
		if ((v & Tn_PER_INT_CAP_MASK) == 0) {
			err = -ENXIO;
			break;
		}
		devp->hd_flags |= HPET_PERIODIC;
		break;
	case HPET_DPI:
		v = readq(&timer->hpet_config);
		if ((v & Tn_PER_INT_CAP_MASK) == 0) {
			err = -ENXIO;
			break;
		}
		if (devp->hd_flags & HPET_PERIODIC &&
		    readq(&timer->hpet_config) & Tn_TYPE_CNF_MASK) {
			v = readq(&timer->hpet_config);
			v ^= Tn_TYPE_CNF_MASK;
			writeq(v, &timer->hpet_config);
		}
		devp->hd_flags &= ~HPET_PERIODIC;
		break;
	case HPET_IRQFREQ:
		if (!kernel && (arg > hpet_max_freq) &&
		    !capable(CAP_SYS_RESOURCE)) {
			err = -EACCES;
			break;
		}

545
		if (!arg) {
L
Linus Torvalds 已提交
546 547 548 549
			err = -EINVAL;
			break;
		}

550
		devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
L
Linus Torvalds 已提交
551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567
	}

	return err;
}

static struct file_operations hpet_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = hpet_read,
	.poll = hpet_poll,
	.ioctl = hpet_ioctl,
	.open = hpet_open,
	.release = hpet_release,
	.fasync = hpet_fasync,
	.mmap = hpet_mmap,
};

R
Randy Dunlap 已提交
568 569 570 571 572 573 574 575 576 577 578
static int hpet_is_known(struct hpet_data *hdp)
{
	struct hpets *hpetp;

	for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
		if (hpetp->hp_hpet_phys == hdp->hd_phys_address)
			return 1;

	return 0;
}

L
Linus Torvalds 已提交
579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602
EXPORT_SYMBOL(hpet_alloc);
EXPORT_SYMBOL(hpet_register);
EXPORT_SYMBOL(hpet_unregister);
EXPORT_SYMBOL(hpet_control);

int hpet_register(struct hpet_task *tp, int periodic)
{
	unsigned int i;
	u64 mask;
	struct hpet_timer __iomem *timer;
	struct hpet_dev *devp;
	struct hpets *hpetp;

	switch (periodic) {
	case 1:
		mask = Tn_PER_INT_CAP_MASK;
		break;
	case 0:
		mask = 0;
		break;
	default:
		return -EINVAL;
	}

603 604
	tp->ht_opaque = NULL;

L
Linus Torvalds 已提交
605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
	spin_lock_irq(&hpet_task_lock);
	spin_lock(&hpet_lock);

	for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
		for (timer = hpetp->hp_hpet->hpet_timers, i = 0;
		     i < hpetp->hp_ntimer; i++, timer++) {
			if ((readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK)
			    != mask)
				continue;

			devp = &hpetp->hp_dev[i];

			if (devp->hd_flags & HPET_OPEN || devp->hd_task) {
				devp = NULL;
				continue;
			}

			tp->ht_opaque = devp;
			devp->hd_task = tp;
			break;
		}

	spin_unlock(&hpet_lock);
	spin_unlock_irq(&hpet_task_lock);

	if (tp->ht_opaque)
		return 0;
	else
		return -EBUSY;
}

static inline int hpet_tpcheck(struct hpet_task *tp)
{
	struct hpet_dev *devp;
	struct hpets *hpetp;

	devp = tp->ht_opaque;

	if (!devp)
		return -ENXIO;

	for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
		if (devp >= hpetp->hp_dev
		    && devp < (hpetp->hp_dev + hpetp->hp_ntimer)
		    && devp->hd_hpet == hpetp->hp_hpet)
			return 0;

	return -ENXIO;
}

int hpet_unregister(struct hpet_task *tp)
{
	struct hpet_dev *devp;
	struct hpet_timer __iomem *timer;
	int err;

	if ((err = hpet_tpcheck(tp)))
		return err;

	spin_lock_irq(&hpet_task_lock);
	spin_lock(&hpet_lock);

	devp = tp->ht_opaque;
	if (devp->hd_task != tp) {
		spin_unlock(&hpet_lock);
		spin_unlock_irq(&hpet_task_lock);
		return -ENXIO;
	}

	timer = devp->hd_timer;
	writeq((readq(&timer->hpet_config) & ~Tn_INT_ENB_CNF_MASK),
	       &timer->hpet_config);
	devp->hd_flags &= ~(HPET_IE | HPET_PERIODIC);
	devp->hd_task = NULL;
	spin_unlock(&hpet_lock);
	spin_unlock_irq(&hpet_task_lock);

	return 0;
}

int hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg)
{
	struct hpet_dev *devp;
	int err;

	if ((err = hpet_tpcheck(tp)))
		return err;

	spin_lock_irq(&hpet_lock);
	devp = tp->ht_opaque;
	if (devp->hd_task != tp) {
		spin_unlock_irq(&hpet_lock);
		return -ENXIO;
	}
	spin_unlock_irq(&hpet_lock);
	return hpet_ioctl_common(devp, cmd, arg, 1);
}

static ctl_table hpet_table[] = {
	{
	 .ctl_name = 1,
	 .procname = "max-user-freq",
	 .data = &hpet_max_freq,
	 .maxlen = sizeof(int),
	 .mode = 0644,
	 .proc_handler = &proc_dointvec,
	 },
	{.ctl_name = 0}
};

static ctl_table hpet_root[] = {
	{
	 .ctl_name = 1,
	 .procname = "hpet",
	 .maxlen = 0,
	 .mode = 0555,
	 .child = hpet_table,
	 },
	{.ctl_name = 0}
};

static ctl_table dev_root[] = {
	{
	 .ctl_name = CTL_DEV,
	 .procname = "dev",
	 .maxlen = 0,
	 .mode = 0555,
	 .child = hpet_root,
	 },
	{.ctl_name = 0}
};

static struct ctl_table_header *sysctl_header;

static void hpet_register_interpolator(struct hpets *hpetp)
{
#ifdef	CONFIG_TIME_INTERPOLATION
	struct time_interpolator *ti;

R
Randy Dunlap 已提交
744
	ti = kzalloc(sizeof(*ti), GFP_KERNEL);
L
Linus Torvalds 已提交
745 746 747 748 749 750
	if (!ti)
		return;

	ti->source = TIME_SOURCE_MMIO64;
	ti->shift = 10;
	ti->addr = &hpetp->hp_hpet->hpet_mc;
751
	ti->frequency = hpetp->hp_tick_freq;
752
	ti->drift = HPET_DRIFT;
L
Linus Torvalds 已提交
753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
	ti->mask = -1;

	hpetp->hp_interpolator = ti;
	register_time_interpolator(ti);
#endif
}

/*
 * Adjustment for when arming the timer with
 * initial conditions.  That is, main counter
 * ticks expired before interrupts are enabled.
 */
#define	TICK_CALIBRATE	(1000UL)

static unsigned long hpet_calibrate(struct hpets *hpetp)
{
	struct hpet_timer __iomem *timer = NULL;
	unsigned long t, m, count, i, flags, start;
	struct hpet_dev *devp;
	int j;
	struct hpet __iomem *hpet;

	for (j = 0, devp = hpetp->hp_dev; j < hpetp->hp_ntimer; j++, devp++)
		if ((devp->hd_flags & HPET_OPEN) == 0) {
			timer = devp->hd_timer;
			break;
		}

	if (!timer)
		return 0;

784
	hpet = hpetp->hp_hpet;
L
Linus Torvalds 已提交
785 786 787
	t = read_counter(&timer->hpet_compare);

	i = 0;
788
	count = hpet_time_div(hpetp, TICK_CALIBRATE);
L
Linus Torvalds 已提交
789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811

	local_irq_save(flags);

	start = read_counter(&hpet->hpet_mc);

	do {
		m = read_counter(&hpet->hpet_mc);
		write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
	} while (i++, (m - start) < count);

	local_irq_restore(flags);

	return (m - start) / i;
}

int hpet_alloc(struct hpet_data *hdp)
{
	u64 cap, mcfg;
	struct hpet_dev *devp;
	u32 i, ntimer;
	struct hpets *hpetp;
	size_t siz;
	struct hpet __iomem *hpet;
R
Randy Dunlap 已提交
812
	static struct hpets *last = NULL;
813
	unsigned long period;
814
	unsigned long long temp;
L
Linus Torvalds 已提交
815 816 817

	/*
	 * hpet_alloc can be called by platform dependent code.
R
Randy Dunlap 已提交
818 819
	 * If platform dependent code has allocated the hpet that
	 * ACPI has also reported, then we catch it here.
L
Linus Torvalds 已提交
820
	 */
R
Randy Dunlap 已提交
821 822 823 824 825
	if (hpet_is_known(hdp)) {
		printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
			__FUNCTION__);
		return 0;
	}
L
Linus Torvalds 已提交
826 827 828 829

	siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
				      sizeof(struct hpet_dev));

R
Randy Dunlap 已提交
830
	hpetp = kzalloc(siz, GFP_KERNEL);
L
Linus Torvalds 已提交
831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863

	if (!hpetp)
		return -ENOMEM;

	hpetp->hp_which = hpet_nhpet++;
	hpetp->hp_hpet = hdp->hd_address;
	hpetp->hp_hpet_phys = hdp->hd_phys_address;

	hpetp->hp_ntimer = hdp->hd_nirqs;

	for (i = 0; i < hdp->hd_nirqs; i++)
		hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];

	hpet = hpetp->hp_hpet;

	cap = readq(&hpet->hpet_cap);

	ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;

	if (hpetp->hp_ntimer != ntimer) {
		printk(KERN_WARNING "hpet: number irqs doesn't agree"
		       " with number of timers\n");
		kfree(hpetp);
		return -ENODEV;
	}

	if (last)
		last->hp_next = hpetp;
	else
		hpets = hpetp;

	last = hpetp;

864 865 866 867 868 869
	period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
		HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
	temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
	temp += period >> 1; /* round */
	do_div(temp, period);
	hpetp->hp_tick_freq = temp; /* ticks per second */
L
Linus Torvalds 已提交
870

871 872
	printk(KERN_INFO "hpet%d: at MMIO 0x%lx (virtual 0x%p), IRQ%s",
		hpetp->hp_which, hdp->hd_phys_address, hdp->hd_address,
L
Linus Torvalds 已提交
873 874 875 876 877
		hpetp->hp_ntimer > 1 ? "s" : "");
	for (i = 0; i < hpetp->hp_ntimer; i++)
		printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
	printk("\n");

878 879 880
	printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",
	       hpetp->hp_which, hpetp->hp_ntimer,
	       cap & HPET_COUNTER_SIZE_MASK ? 64 : 32, hpetp->hp_tick_freq);
L
Linus Torvalds 已提交
881 882 883 884 885 886 887 888

	mcfg = readq(&hpet->hpet_config);
	if ((mcfg & HPET_ENABLE_CNF_MASK) == 0) {
		write_counter(0L, &hpet->hpet_mc);
		mcfg |= HPET_ENABLE_CNF_MASK;
		writeq(mcfg, &hpet->hpet_config);
	}

889
	for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer; i++, devp++) {
L
Linus Torvalds 已提交
890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926
		struct hpet_timer __iomem *timer;

		timer = &hpet->hpet_timers[devp - hpetp->hp_dev];

		devp->hd_hpets = hpetp;
		devp->hd_hpet = hpet;
		devp->hd_timer = timer;

		/*
		 * If the timer was reserved by platform code,
		 * then make timer unavailable for opens.
		 */
		if (hdp->hd_state & (1 << i)) {
			devp->hd_flags = HPET_OPEN;
			continue;
		}

		init_waitqueue_head(&devp->hd_waitqueue);
	}

	hpetp->hp_delta = hpet_calibrate(hpetp);
	hpet_register_interpolator(hpetp);

	return 0;
}

static acpi_status hpet_resources(struct acpi_resource *res, void *data)
{
	struct hpet_data *hdp;
	acpi_status status;
	struct acpi_resource_address64 addr;

	hdp = data;

	status = acpi_resource_to_address64(res, &addr);

	if (ACPI_SUCCESS(status)) {
B
Bob Moore 已提交
927
		hdp->hd_phys_address = addr.minimum;
928
		hdp->hd_address = ioremap(addr.minimum, addr.address_length);
L
Linus Torvalds 已提交
929

R
Randy Dunlap 已提交
930 931 932 933 934 935
		if (hpet_is_known(hdp)) {
			printk(KERN_DEBUG "%s: 0x%lx is busy\n",
				__FUNCTION__, hdp->hd_phys_address);
			iounmap(hdp->hd_address);
			return -EBUSY;
		}
B
Bob Moore 已提交
936 937
	} else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
		struct acpi_resource_fixed_memory32 *fixmem32;
938 939 940 941 942

		fixmem32 = &res->data.fixed_memory32;
		if (!fixmem32)
			return -EINVAL;

B
Bob Moore 已提交
943 944
		hdp->hd_phys_address = fixmem32->address;
		hdp->hd_address = ioremap(fixmem32->address,
945 946
						HPET_RANGE_SIZE);

R
Randy Dunlap 已提交
947 948 949 950 951 952
		if (hpet_is_known(hdp)) {
			printk(KERN_DEBUG "%s: 0x%lx is busy\n",
				__FUNCTION__, hdp->hd_phys_address);
			iounmap(hdp->hd_address);
			return -EBUSY;
		}
B
Bob Moore 已提交
953 954
	} else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
		struct acpi_resource_extended_irq *irqp;
955
		int i, irq;
L
Linus Torvalds 已提交
956 957 958

		irqp = &res->data.extended_irq;

959 960 961 962 963 964 965 966
		for (i = 0; i < irqp->interrupt_count; i++) {
			irq = acpi_register_gsi(irqp->interrupts[i],
				      irqp->triggering, irqp->polarity);
			if (irq < 0)
				return AE_ERROR;

			hdp->hd_irq[hdp->hd_nirqs] = irq;
			hdp->hd_nirqs++;
L
Linus Torvalds 已提交
967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047
		}
	}

	return AE_OK;
}

static int hpet_acpi_add(struct acpi_device *device)
{
	acpi_status result;
	struct hpet_data data;

	memset(&data, 0, sizeof(data));

	result =
	    acpi_walk_resources(device->handle, METHOD_NAME__CRS,
				hpet_resources, &data);

	if (ACPI_FAILURE(result))
		return -ENODEV;

	if (!data.hd_address || !data.hd_nirqs) {
		printk("%s: no address or irqs in _CRS\n", __FUNCTION__);
		return -ENODEV;
	}

	return hpet_alloc(&data);
}

static int hpet_acpi_remove(struct acpi_device *device, int type)
{
	/* XXX need to unregister interpolator, dealloc mem, etc */
	return -EINVAL;
}

static struct acpi_driver hpet_acpi_driver = {
	.name = "hpet",
	.ids = "PNP0103",
	.ops = {
		.add = hpet_acpi_add,
		.remove = hpet_acpi_remove,
		},
};

static struct miscdevice hpet_misc = { HPET_MINOR, "hpet", &hpet_fops };

static int __init hpet_init(void)
{
	int result;

	result = misc_register(&hpet_misc);
	if (result < 0)
		return -ENODEV;

	sysctl_header = register_sysctl_table(dev_root, 0);

	result = acpi_bus_register_driver(&hpet_acpi_driver);
	if (result < 0) {
		if (sysctl_header)
			unregister_sysctl_table(sysctl_header);
		misc_deregister(&hpet_misc);
		return result;
	}

	return 0;
}

static void __exit hpet_exit(void)
{
	acpi_bus_unregister_driver(&hpet_acpi_driver);

	if (sysctl_header)
		unregister_sysctl_table(sysctl_header);
	misc_deregister(&hpet_misc);

	return;
}

module_init(hpet_init);
module_exit(hpet_exit);
MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
MODULE_LICENSE("GPL");