Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 994 insertions, 0 deletions

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
new file mode 100644
index 000000000000..5ec732e6ca92
--- /dev/null
+++ b/drivers/char/hpet.c
@@ -0,0 +1,994 @@
+/*
+ * 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/config.h>
+#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.
+ * http://www.intel.com/labs/platcomp/hpet/hpetspec.htm
+ */
+#define HPET_USER_FREQ  (64)
+#define HPET_DRIFT      (500)
+
+static u32 hpet_ntimer, hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
+
+/* 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;
+        unsigned long hp_period;
+        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
+
+#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
+static unsigned long long __inline readq(void __iomem *addr)
+{
+        return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
+}
+#endif
+
+#ifndef writeq
+static void __inline writeq(unsigned long long v, void __iomem *addr)
+{
+        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;
+
+        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);
+        }
+
+        isr = (1 << (devp - devp->hd_hpets->hp_dev));
+        writeq(isr, &devp->hd_hpet->hpet_isr);
+        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);
+        addr = __pa(addr);
+
+        if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
+                                        PAGE_SIZE, vma->vm_page_prot)) {
+                printk(KERN_ERR "remap_pfn_range failed in hpet.c\n");
+                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;
+
+        v = readq(&timer->hpet_config);
+        spin_lock_irq(&hpet_lock);
+
+        if (devp->hd_flags & HPET_IE) {
+                spin_unlock_irq(&hpet_lock);
+                return -EBUSY;
+        }
+
+        devp->hd_flags |= HPET_IE;
+        spin_unlock_irq(&hpet_lock);
+
+        t = readq(&timer->hpet_config);
+        irq = devp->hd_hdwirq;
+
+        if (irq) {
+                sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
+
+                if (request_irq
+                    (irq, hpet_interrupt, SA_INTERRUPT, devp->hd_name, (void *)devp)) {
+                        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);
+        }
+
+        isr = (1 << (devp - hpets->hp_dev));
+        writeq(isr, &hpet->hpet_isr);
+        writeq(g, &timer->hpet_config);
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static inline unsigned long hpet_time_div(unsigned long dis)
+{
+        unsigned long long m = 1000000000000000ULL;
+
+        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;
+
+                        info.hi_ireqfreq = hpet_time_div(hpetp->hp_period *
+                                                         devp->hd_ireqfreq);
+                        info.hi_flags =
+                            readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
+                        info.hi_hpet = devp->hd_hpets->hp_which;
+                        info.hi_timer = devp - devp->hd_hpets->hp_dev;
+                        if (copy_to_user((void __user *)arg, &info, sizeof(info)))
+                                err = -EFAULT;
+                        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;
+                }
+
+                if (arg & (arg - 1)) {
+                        err = -EINVAL;
+                        break;
+                }
+
+                devp->hd_ireqfreq = hpet_time_div(hpetp->hp_period * arg);
+        }
+
+        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,
+};
+
+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;
+        }
+
+        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;
+
+        ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+        if (!ti)
+                return;
+
+        memset(ti, 0, sizeof(*ti));
+        ti->source = TIME_SOURCE_MMIO64;
+        ti->shift = 10;
+        ti->addr = &hpetp->hp_hpet->hpet_mc;
+        ti->frequency = hpet_time_div(hpets->hp_period);
+        ti->drift = ti->frequency * HPET_DRIFT / 1000000;
+        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;
+
+        hpet = hpets->hp_hpet;
+        t = read_counter(&timer->hpet_compare);
+
+        i = 0;
+        count = hpet_time_div(hpetp->hp_period * TICK_CALIBRATE);
+
+        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;
+        static struct hpets *last = (struct hpets *)0;
+        unsigned long ns;
+
+        /*
+         * hpet_alloc can be called by platform dependent code.
+         * if platform dependent code has allocated the hpet
+         * ACPI also reports hpet, then we catch it here.
+         */
+        for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
+                if (hpetp->hp_hpet == hdp->hd_address)
+                        return 0;
+
+        siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
+                                      sizeof(struct hpet_dev));
+
+        hpetp = kmalloc(siz, GFP_KERNEL);
+
+        if (!hpetp)
+                return -ENOMEM;
+
+        memset(hpetp, 0, siz);
+
+        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;
+
+        hpetp->hp_period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
+            HPET_COUNTER_CLK_PERIOD_SHIFT;
+
+        printk(KERN_INFO "hpet%d: at MMIO 0x%lx, IRQ%s",
+                hpetp->hp_which, hdp->hd_phys_address,
+                hpetp->hp_ntimer > 1 ? "s" : "");
+        for (i = 0; i < hpetp->hp_ntimer; i++)
+                printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
+        printk("\n");
+
+        ns = hpetp->hp_period;  /* femptoseconds, 10^-15 */
+        do_div(ns, 1000000);    /* convert to nanoseconds, 10^-9 */
+        printk(KERN_INFO "hpet%d: %ldns tick, %d %d-bit timers\n",
+                hpetp->hp_which, ns, hpetp->hp_ntimer,
+                cap & HPET_COUNTER_SIZE_MASK ? 64 : 32);
+
+        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);
+        }
+
+        for (i = 0, devp = hpetp->hp_dev; i < hpetp->hp_ntimer;
+             i++, hpet_ntimer++, devp++) {
+                unsigned long v;
+                struct hpet_timer __iomem *timer;
+
+                timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
+                v = readq(&timer->hpet_config);
+
+                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;
+        struct hpets *hpetp;
+
+        hdp = data;
+
+        status = acpi_resource_to_address64(res, &addr);
+
+        if (ACPI_SUCCESS(status)) {
+                unsigned long size;
+
+                size = addr.max_address_range - addr.min_address_range + 1;
+                hdp->hd_phys_address = addr.min_address_range;
+                hdp->hd_address = ioremap(addr.min_address_range, size);
+
+                for (hpetp = hpets; hpetp; hpetp = hpetp->hp_next)
+                        if (hpetp->hp_hpet == hdp->hd_address)
+                                return -EBUSY;
+        } else if (res->id == ACPI_RSTYPE_EXT_IRQ) {
+                struct acpi_resource_ext_irq *irqp;
+                int i;
+
+                irqp = &res->data.extended_irq;
+
+                if (irqp->number_of_interrupts > 0) {
+                        hdp->hd_nirqs = irqp->number_of_interrupts;
+
+                        for (i = 0; i < hdp->hd_nirqs; i++)
+                                hdp->hd_irq[i] =
+                                    acpi_register_gsi(irqp->interrupts[i],
+                                                      irqp->edge_level,
+                                                      irqp->active_high_low);
+                }
+        }
+
+        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");