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Commit cea2509a authored by Jesse Barnes's avatar Jesse Barnes Committed by Linus Torvalds
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[PATCH] mmtimer cleanups 

A few cleanups that probably should have been done a long time ago:

  o remove test program from mmtimer.h
  o move name, desc., etc. #defines from mmtimer.h to mmtimer.c
  o document what mmtimer.c is a little better
  o some whitespace cleanups for linewrapping and such
Signed-off-by: default avatarJesse Barnes <jbarnes@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 38c75d44
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Showing with 38 additions and 107 deletions
drivers/char/mmtimer.c
View file @ cea2509a
......@@ -5,10 +5,11 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2001-2003 Silicon Graphics, Inc. All rights reserved.
* Copyright (c) 2001-2004 Silicon Graphics, Inc. All rights reserved.
*
* This driver implements a subset of the interface required by the
* IA-PC Multimedia Timers Draft Specification (rev. 0.97) from Intel.
* This driver exports an API that should be supportable by any HPET or IA-PC
* multimedia timer. The code below is currently specific to the SGI Altix
* SHub RTC, however.
*
* 11/01/01 - jbarnes - initial revision
* 9/10/04 - Christoph Lameter - remove interrupt support for kernel inclusion
......@@ -32,9 +33,15 @@ MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
MODULE_DESCRIPTION("Multimedia timer support");
MODULE_LICENSE("GPL");
/* name of the device, usually in /dev */
#define MMTIMER_NAME "mmtimer"
#define MMTIMER_DESC "IA-PC Multimedia Timer"
#define MMTIMER_VERSION "1.0"
#define RTC_BITS 55 /* 55 bits for this implementation */
static int mmtimer_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
static int mmtimer_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg);
static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
/*
......@@ -55,8 +62,10 @@ static struct file_operations mmtimer_fops = {
* @cmd: command to execute
* @arg: optional argument to command
*
* Executes the command specified by @cmd. Returns 0 for success, <0 for failure.
* Valid commands are
* Executes the command specified by @cmd. Returns 0 for success, < 0 for
* failure.
*
* Valid commands:
*
* %MMTIMER_GETOFFSET - Should return the offset (relative to the start
* of the page where the registers are mapped) for the counter in question.
......@@ -74,8 +83,8 @@ static struct file_operations mmtimer_fops = {
* %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
* in the address specified by @arg.
*/
static int
mmtimer_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
static int mmtimer_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int ret = 0;
......@@ -91,12 +100,15 @@ mmtimer_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
break;
case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
if(copy_to_user((unsigned long *)arg, &mmtimer_femtoperiod, sizeof(unsigned long)))
if(copy_to_user((unsigned long *)arg, &mmtimer_femtoperiod,
sizeof(unsigned long)))
return -EFAULT;
break;
case MMTIMER_GETFREQ: /* frequency in Hz */
if(copy_to_user((unsigned long *)arg, &sn_rtc_cycles_per_second, sizeof(unsigned long)))
if(copy_to_user((unsigned long *)arg,
&sn_rtc_cycles_per_second,
sizeof(unsigned long)))
return -EFAULT;
ret = 0;
break;
......@@ -110,7 +122,8 @@ mmtimer_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
break;
case MMTIMER_GETCOUNTER:
if(copy_to_user((unsigned long *)arg, RTC_COUNTER_ADDR, sizeof(unsigned long)))
if(copy_to_user((unsigned long *)arg, RTC_COUNTER_ADDR,
sizeof(unsigned long)))
return -EFAULT;
break;
default:
......@@ -129,8 +142,7 @@ mmtimer_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned
* Calls remap_page_range() to map the clock's registers into
* the calling process' address space.
*/
static int
mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long mmtimer_addr;
......@@ -150,7 +162,8 @@ mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
mmtimer_addr &= ~(PAGE_SIZE - 1);
mmtimer_addr &= 0xfffffffffffffffUL;
if (remap_page_range(vma, vma->vm_start, mmtimer_addr, PAGE_SIZE, vma->vm_page_prot)) {
if (remap_page_range(vma, vma->vm_start, mmtimer_addr, PAGE_SIZE,
vma->vm_page_prot)) {
printk(KERN_ERR "remap_page_range failed in mmtimer.c\n");
return -EAGAIN;
}
......@@ -169,27 +182,29 @@ static struct miscdevice mmtimer_miscdev = {
*
* Does initial setup for the mmtimer device.
*/
static int __init
mmtimer_init(void)
static int __init mmtimer_init(void)
{
/*
* Sanity check the cycles/sec variable
*/
if (sn_rtc_cycles_per_second < 100000) {
printk(KERN_ERR "%s: unable to determine clock frequency\n", MMTIMER_NAME);
printk(KERN_ERR "%s: unable to determine clock frequency\n",
MMTIMER_NAME);
return -1;
}
mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second / 2) /
sn_rtc_cycles_per_second;
mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
2) / sn_rtc_cycles_per_second;
strcpy(mmtimer_miscdev.devfs_name, MMTIMER_NAME);
if (misc_register(&mmtimer_miscdev)) {
printk(KERN_ERR "%s: failed to register device\n", MMTIMER_NAME);
printk(KERN_ERR "%s: failed to register device\n",
MMTIMER_NAME);
return -1;
}
printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION, sn_rtc_cycles_per_second/(unsigned long)1E6);
printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION,
sn_rtc_cycles_per_second/(unsigned long)1E6);
return 0;
}
......
include/linux/mmtimer.h
View file @ cea2509a
......@@ -5,7 +5,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2001-2003 Silicon Graphics, Inc. All rights reserved.
* Copyright (c) 2001-2004 Silicon Graphics, Inc. All rights reserved.
*
* This file should define an interface compatible with the IA-PC Multimedia
* Timers Draft Specification (rev. 0.97) from Intel. Note that some
......@@ -14,17 +14,12 @@
*
* 11/01/01 - jbarnes - initial revision
* 9/10/04 - Christoph Lameter - remove interrupt support
* 9/17/04 - jbarnes - remove test program, move some #defines to the driver
*/
#ifndef _LINUX_MMTIMER_H
#define _LINUX_MMTIMER_H
/* name of the device, usually in /dev */
#define MMTIMER_NAME "mmtimer"
#define MMTIMER_FULLNAME "/dev/mmtimer"
#define MMTIMER_DESC "IA-PC Multimedia Timer"
#define MMTIMER_VERSION "1.0"
/*
* Breakdown of the ioctl's available. An 'optional' next to the command
* indicates that supporting this command is optional, while 'required'
......@@ -58,83 +53,4 @@
#define MMTIMER_MMAPAVAIL _IO(MMTIMER_IOCTL_BASE, 6)
#define MMTIMER_GETCOUNTER _IOR(MMTIMER_IOCTL_BASE, 9, unsigned long)
/*
* An mmtimer verification program. WARNINGs are ok, but ERRORs indicate
* that the device doesn't fully support the interface defined here.
*/
#ifdef _MMTIMER_TEST_PROGRAM
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include "mmtimer.h"
int main(int argc, char *argv[])
{
int result, fd;
unsigned long val = 0;
unsigned long i;
if((fd = open("/dev/"MMTIMER_NAME, O_RDONLY)) == -1) {
printf("failed to open /dev/%s", MMTIMER_NAME);
return 1;
}
/*
* Can we mmap in the counter?
*/
if((result = ioctl(fd, MMTIMER_MMAPAVAIL, 0)) == 1) {
printf("mmap available\n");
/* ... so try getting the offset for each clock */
if((result = ioctl(fd, MMTIMER_GETOFFSET, 0)) != -ENOSYS)
printf("offset: %d\n", result);
else
printf("WARNING: offset unavailable for clock\n");
}
else
printf("WARNING: mmap unavailable\n");
/*
* Get the resolution in femtoseconds
*/
if((result = ioctl(fd, MMTIMER_GETRES, &val)) != -ENOSYS)
printf("resolution: %ld femtoseconds\n", val);
else
printf("ERROR: failed to get resolution\n");
/*
* Get the frequency in Hz
*/
if((result = ioctl(fd, MMTIMER_GETFREQ, &val)) != -ENOSYS)
if(val < 10000000) /* less than 10 MHz? */
printf("ERROR: frequency only %ld MHz, should be >= 10 MHz\n", val/1000000);
else
printf("frequency: %ld MHz\n", val/1000000);
else
printf("ERROR: failed to get frequency\n");
/*
* How many bits in the counter?
*/
if((result = ioctl(fd, MMTIMER_GETBITS, 0)) != -ENOSYS)
printf("bits in counter: %d\n", result);
else
printf("ERROR: can't get number of bits in counter\n");
if((result = ioctl(fd, MMTIMER_GETCOUNTER, &val)) != -ENOSYS)
printf("counter value: %ld\n", val);
else
printf("ERROR: can't get counter value\n");
return 0;
}
#endif /* _MMTIMER_TEST_PROGRM */
#endif /* _LINUX_MMTIMER_H */
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