linux/drivers/char/hpet.c
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00

1087 lines
24 KiB
C

/*
* 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/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/mm.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/sysctl.h>
#include <linux/wait.h>
#include <linux/sched/signal.h>
#include <linux/bcd.h>
#include <linux/seq_file.h>
#include <linux/bitops.h>
#include <linux/compat.h>
#include <linux/clocksource.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/acpi.h>
#include <linux/hpet.h>
#include <asm/current.h>
#include <asm/irq.h>
#include <asm/div64.h>
/*
* The High Precision Event Timer driver.
* This driver is closely modelled after the rtc.c driver.
* See HPET spec revision 1.
*/
#define HPET_USER_FREQ (64)
#define HPET_DRIFT (500)
#define HPET_RANGE_SIZE 1024 /* from HPET spec */
/* WARNING -- don't get confused. These macros are never used
* to write the (single) counter, and rarely to read it.
* They're badly named; to fix, someday.
*/
#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
static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */
static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
/* This clocksource driver currently only works on ia64 */
#ifdef CONFIG_IA64
static void __iomem *hpet_mctr;
static u64 read_hpet(struct clocksource *cs)
{
return (u64)read_counter((void __iomem *)hpet_mctr);
}
static struct clocksource clocksource_hpet = {
.name = "hpet",
.rating = 250,
.read = read_hpet,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct clocksource *hpet_clocksource;
#endif
/* A lock for concurrent access by app and isr hpet activity. */
static DEFINE_SPINLOCK(hpet_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;
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 clocksource *hp_clocksource;
unsigned long long hp_tick_freq;
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
#define HPET_SHARED_IRQ 0x0008
#ifndef readq
static inline unsigned long long readq(void __iomem *addr)
{
return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
}
#endif
#ifndef writeq
static inline void 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 hpet_dev *devp;
unsigned long isr;
devp = data;
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;
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, mc, base, k;
struct hpet __iomem *hpet = devp->hd_hpet;
struct hpets *hpetp = devp->hd_hpets;
t = devp->hd_ireqfreq;
m = read_counter(&devp->hd_timer->hpet_compare);
mc = read_counter(&hpet->hpet_mc);
/* The time for the next interrupt would logically be t + m,
* however, if we are very unlucky and the interrupt is delayed
* for longer than t then we will completely miss the next
* interrupt if we set t + m and an application will hang.
* Therefore we need to make a more complex computation assuming
* that there exists a k for which the following is true:
* k * t + base < mc + delta
* (k + 1) * t + base > mc + delta
* where t is the interval in hpet ticks for the given freq,
* base is the theoretical start value 0 < base < t,
* mc is the main counter value at the time of the interrupt,
* delta is the time it takes to write the a value to the
* comparator.
* k may then be computed as (mc - base + delta) / t .
*/
base = mc % t;
k = (mc - base + hpetp->hp_delta) / t;
write_counter(t * (k + 1) + base,
&devp->hd_timer->hpet_compare);
}
if (devp->hd_flags & HPET_SHARED_IRQ)
writel(isr, &devp->hd_hpet->hpet_isr);
spin_unlock(&hpet_lock);
wake_up_interruptible(&devp->hd_waitqueue);
kill_fasync(&devp->hd_async_queue, SIGIO, POLL_IN);
return IRQ_HANDLED;
}
static void hpet_timer_set_irq(struct hpet_dev *devp)
{
unsigned long v;
int irq, gsi;
struct hpet_timer __iomem *timer;
spin_lock_irq(&hpet_lock);
if (devp->hd_hdwirq) {
spin_unlock_irq(&hpet_lock);
return;
}
timer = devp->hd_timer;
/* we prefer level triggered mode */
v = readl(&timer->hpet_config);
if (!(v & Tn_INT_TYPE_CNF_MASK)) {
v |= Tn_INT_TYPE_CNF_MASK;
writel(v, &timer->hpet_config);
}
spin_unlock_irq(&hpet_lock);
v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
Tn_INT_ROUTE_CAP_SHIFT;
/*
* In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
* legacy device. In IO APIC mode, we skip all the legacy IRQS.
*/
if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
v &= ~0xf3df;
else
v &= ~0xffff;
for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
if (irq >= nr_irqs) {
irq = HPET_MAX_IRQ;
break;
}
gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE,
ACPI_ACTIVE_LOW);
if (gsi > 0)
break;
/* FIXME: Setup interrupt source table */
}
if (irq < HPET_MAX_IRQ) {
spin_lock_irq(&hpet_lock);
v = readl(&timer->hpet_config);
v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
writel(v, &timer->hpet_config);
devp->hd_hdwirq = gsi;
spin_unlock_irq(&hpet_lock);
}
return;
}
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;
mutex_lock(&hpet_mutex);
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)
continue;
else {
devp = &hpetp->hp_dev[i];
break;
}
if (!devp) {
spin_unlock_irq(&hpet_lock);
mutex_unlock(&hpet_mutex);
return -EBUSY;
}
file->private_data = devp;
devp->hd_irqdata = 0;
devp->hd_flags |= HPET_OPEN;
spin_unlock_irq(&hpet_lock);
mutex_unlock(&hpet_mutex);
hpet_timer_set_irq(devp);
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 __poll_t 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 EPOLLIN | EPOLLRDNORM;
return 0;
}
#ifdef CONFIG_HPET_MMAP
#ifdef CONFIG_HPET_MMAP_DEFAULT
static int hpet_mmap_enabled = 1;
#else
static int hpet_mmap_enabled = 0;
#endif
static __init int hpet_mmap_enable(char *str)
{
get_option(&str, &hpet_mmap_enabled);
pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled");
return 1;
}
__setup("hpet_mmap", hpet_mmap_enable);
static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
{
struct hpet_dev *devp;
unsigned long addr;
if (!hpet_mmap_enabled)
return -EACCES;
devp = file->private_data;
addr = devp->hd_hpets->hp_hpet_phys;
if (addr & (PAGE_SIZE - 1))
return -ENOSYS;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
return vm_iomap_memory(vma, addr, PAGE_SIZE);
}
#else
static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
{
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);
file->private_data = NULL;
return 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;
if (!devp->hd_ireqfreq)
return -EIO;
spin_lock_irq(&hpet_lock);
if (devp->hd_flags & HPET_IE) {
spin_unlock_irq(&hpet_lock);
return -EBUSY;
}
devp->hd_flags |= HPET_IE;
if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
devp->hd_flags |= HPET_SHARED_IRQ;
spin_unlock_irq(&hpet_lock);
irq = devp->hd_hdwirq;
if (irq) {
unsigned long irq_flags;
if (devp->hd_flags & HPET_SHARED_IRQ) {
/*
* To prevent the interrupt handler from seeing an
* unwanted interrupt status bit, program the timer
* so that it will not fire in the near future ...
*/
writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK,
&timer->hpet_config);
write_counter(read_counter(&hpet->hpet_mc),
&timer->hpet_compare);
/* ... and clear any left-over status. */
isr = 1 << (devp - devp->hd_hpets->hp_dev);
writel(isr, &hpet->hpet_isr);
}
sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));
irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0;
if (request_irq(irq, hpet_interrupt, irq_flags,
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);
/* 64-bit comparators are not yet supported through the ioctls,
* so force this into 32-bit mode if it supports both modes
*/
g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK;
if (devp->hd_flags & HPET_PERIODIC) {
g |= Tn_TYPE_CNF_MASK;
v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK;
writeq(v, &timer->hpet_config);
local_irq_save(flags);
/*
* NOTE: First we modify the hidden accumulator
* register supported by periodic-capable comparators.
* We never want to modify the (single) counter; that
* would affect all the comparators. The value written
* is the counter value when the first interrupt is due.
*/
m = read_counter(&hpet->hpet_mc);
write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
/*
* Then we modify the comparator, indicating the period
* for subsequent interrupt.
*/
write_counter(t, &timer->hpet_compare);
} else {
local_irq_save(flags);
m = read_counter(&hpet->hpet_mc);
write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
}
if (devp->hd_flags & HPET_SHARED_IRQ) {
isr = 1 << (devp - devp->hd_hpets->hp_dev);
writel(isr, &hpet->hpet_isr);
}
writeq(g, &timer->hpet_config);
local_irq_restore(flags);
return 0;
}
/* converts Hz to number of timer ticks */
static inline unsigned long hpet_time_div(struct hpets *hpets,
unsigned long dis)
{
unsigned long long m;
m = hpets->hp_tick_freq + (dis >> 1);
do_div(m, dis);
return (unsigned long)m;
}
static int
hpet_ioctl_common(struct hpet_dev *devp, unsigned int cmd, unsigned long arg,
struct hpet_info *info)
{
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:
{
memset(info, 0, sizeof(*info));
if (devp->hd_ireqfreq)
info->hi_ireqfreq =
hpet_time_div(hpetp, devp->hd_ireqfreq);
info->hi_flags =
readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
info->hi_hpet = hpetp->hp_which;
info->hi_timer = devp - hpetp->hp_dev;
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 ((arg > hpet_max_freq) &&
!capable(CAP_SYS_RESOURCE)) {
err = -EACCES;
break;
}
if (!arg) {
err = -EINVAL;
break;
}
devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
}
return err;
}
static long
hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct hpet_info info;
int err;
mutex_lock(&hpet_mutex);
err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
mutex_unlock(&hpet_mutex);
if ((cmd == HPET_INFO) && !err &&
(copy_to_user((void __user *)arg, &info, sizeof(info))))
err = -EFAULT;
return err;
}
#ifdef CONFIG_COMPAT
struct compat_hpet_info {
compat_ulong_t hi_ireqfreq; /* Hz */
compat_ulong_t hi_flags; /* information */
unsigned short hi_hpet;
unsigned short hi_timer;
};
static long
hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct hpet_info info;
int err;
mutex_lock(&hpet_mutex);
err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
mutex_unlock(&hpet_mutex);
if ((cmd == HPET_INFO) && !err) {
struct compat_hpet_info __user *u = compat_ptr(arg);
if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||
put_user(info.hi_flags, &u->hi_flags) ||
put_user(info.hi_hpet, &u->hi_hpet) ||
put_user(info.hi_timer, &u->hi_timer))
err = -EFAULT;
}
return err;
}
#endif
static const struct file_operations hpet_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = hpet_read,
.poll = hpet_poll,
.unlocked_ioctl = hpet_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = hpet_compat_ioctl,
#endif
.open = hpet_open,
.release = hpet_release,
.fasync = hpet_fasync,
.mmap = hpet_mmap,
};
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;
}
static struct ctl_table hpet_table[] = {
{
.procname = "max-user-freq",
.data = &hpet_max_freq,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{}
};
static struct ctl_table hpet_root[] = {
{
.procname = "hpet",
.maxlen = 0,
.mode = 0555,
.child = hpet_table,
},
{}
};
static struct ctl_table dev_root[] = {
{
.procname = "dev",
.maxlen = 0,
.mode = 0555,
.child = hpet_root,
},
{}
};
static struct ctl_table_header *sysctl_header;
/*
* 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 = hpetp->hp_hpet;
t = read_counter(&timer->hpet_compare);
i = 0;
count = hpet_time_div(hpetp, 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;
}
static unsigned long hpet_calibrate(struct hpets *hpetp)
{
unsigned long ret = ~0UL;
unsigned long tmp;
/*
* Try to calibrate until return value becomes stable small value.
* If SMI interruption occurs in calibration loop, the return value
* will be big. This avoids its impact.
*/
for ( ; ; ) {
tmp = __hpet_calibrate(hpetp);
if (ret <= tmp)
break;
ret = tmp;
}
return ret;
}
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;
unsigned long period;
unsigned long long temp;
u32 remainder;
/*
* hpet_alloc can be called by platform dependent code.
* If platform dependent code has allocated the hpet that
* ACPI has also reported, then we catch it here.
*/
if (hpet_is_known(hdp)) {
printk(KERN_DEBUG "%s: duplicate HPET ignored\n",
__func__);
return 0;
}
siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
sizeof(struct hpet_dev));
hpetp = kzalloc(siz, GFP_KERNEL);
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;
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 */
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(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
printk(KERN_CONT "\n");
temp = hpetp->hp_tick_freq;
remainder = do_div(temp, 1000000);
printk(KERN_INFO
"hpet%u: %u comparators, %d-bit %u.%06u MHz counter\n",
hpetp->hp_which, hpetp->hp_ntimer,
cap & HPET_COUNTER_SIZE_MASK ? 64 : 32,
(unsigned) temp, remainder);
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++, devp++) {
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);
/* This clocksource driver currently only works on ia64 */
#ifdef CONFIG_IA64
if (!hpet_clocksource) {
hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
clocksource_hpet.archdata.fsys_mmio = hpet_mctr;
clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
hpetp->hp_clocksource = &clocksource_hpet;
hpet_clocksource = &clocksource_hpet;
}
#endif
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)) {
hdp->hd_phys_address = addr.address.minimum;
hdp->hd_address = ioremap(addr.address.minimum, addr.address.address_length);
if (hpet_is_known(hdp)) {
iounmap(hdp->hd_address);
return AE_ALREADY_EXISTS;
}
} else if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
struct acpi_resource_fixed_memory32 *fixmem32;
fixmem32 = &res->data.fixed_memory32;
hdp->hd_phys_address = fixmem32->address;
hdp->hd_address = ioremap(fixmem32->address,
HPET_RANGE_SIZE);
if (hpet_is_known(hdp)) {
iounmap(hdp->hd_address);
return AE_ALREADY_EXISTS;
}
} else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ) {
struct acpi_resource_extended_irq *irqp;
int i, irq;
irqp = &res->data.extended_irq;
for (i = 0; i < irqp->interrupt_count; i++) {
if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
break;
irq = acpi_register_gsi(NULL, irqp->interrupts[i],
irqp->triggering, irqp->polarity);
if (irq < 0)
return AE_ERROR;
hdp->hd_irq[hdp->hd_nirqs] = irq;
hdp->hd_nirqs++;
}
}
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) {
if (data.hd_address)
iounmap(data.hd_address);
printk("%s: no address or irqs in _CRS\n", __func__);
return -ENODEV;
}
return hpet_alloc(&data);
}
static const struct acpi_device_id hpet_device_ids[] = {
{"PNP0103", 0},
{"", 0},
};
static struct acpi_driver hpet_acpi_driver = {
.name = "hpet",
.ids = hpet_device_ids,
.ops = {
.add = hpet_acpi_add,
},
};
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);
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;
}
device_initcall(hpet_init);
/*
MODULE_AUTHOR("Bob Picco <Robert.Picco@hp.com>");
MODULE_LICENSE("GPL");
*/