summaryrefslogtreecommitdiff
path: root/drivers/char/hpet.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 22:20:36 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 22:20:36 (GMT)
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/hpet.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-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!
Diffstat (limited to 'drivers/char/hpet.c')
-rw-r--r--drivers/char/hpet.c994
1 files changed, 994 insertions, 0 deletions
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
new file mode 100644
index 0000000..5ec732e
--- /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");