kernel_optimize_test/arch/m68k/mvme16x/rtc.c
Arjan van de Ven 5dfe4c964a [PATCH] mark struct file_operations const 2
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@osdl.org: sparc64 fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:44 -08:00

172 lines
3.9 KiB
C

/*
* Real Time Clock interface for Linux on the MVME16x
*
* Based on the PC driver by Paul Gortmaker.
*/
#define RTC_VERSION "1.00"
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */
#include <linux/smp_lock.h>
#include <linux/bcd.h>
#include <asm/mvme16xhw.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/setup.h>
/*
* We sponge a minor off of the misc major. No need slurping
* up another valuable major dev number for this. If you add
* an ioctl, make sure you don't conflict with SPARC's RTC
* ioctls.
*/
static const unsigned char days_in_mo[] =
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static atomic_t rtc_ready = ATOMIC_INIT(1);
static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
unsigned long flags;
struct rtc_time wtime;
void __user *argp = (void __user *)arg;
switch (cmd) {
case RTC_RD_TIME: /* Read the time/date from RTC */
{
local_irq_save(flags);
/* Ensure clock and real-time-mode-register are accessible */
rtc->ctrl = RTC_READ;
memset(&wtime, 0, sizeof(struct rtc_time));
wtime.tm_sec = BCD2BIN(rtc->bcd_sec);
wtime.tm_min = BCD2BIN(rtc->bcd_min);
wtime.tm_hour = BCD2BIN(rtc->bcd_hr);
wtime.tm_mday = BCD2BIN(rtc->bcd_dom);
wtime.tm_mon = BCD2BIN(rtc->bcd_mth)-1;
wtime.tm_year = BCD2BIN(rtc->bcd_year);
if (wtime.tm_year < 70)
wtime.tm_year += 100;
wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;
rtc->ctrl = 0;
local_irq_restore(flags);
return copy_to_user(argp, &wtime, sizeof wtime) ?
-EFAULT : 0;
}
case RTC_SET_TIME: /* Set the RTC */
{
struct rtc_time rtc_tm;
unsigned char mon, day, hrs, min, sec, leap_yr;
unsigned int yrs;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
return -EFAULT;
yrs = rtc_tm.tm_year;
if (yrs < 1900)
yrs += 1900;
mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
day = rtc_tm.tm_mday;
hrs = rtc_tm.tm_hour;
min = rtc_tm.tm_min;
sec = rtc_tm.tm_sec;
leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
if ((mon > 12) || (day == 0))
return -EINVAL;
if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
return -EINVAL;
if ((hrs >= 24) || (min >= 60) || (sec >= 60))
return -EINVAL;
if (yrs >= 2070)
return -EINVAL;
local_irq_save(flags);
rtc->ctrl = RTC_WRITE;
rtc->bcd_sec = BIN2BCD(sec);
rtc->bcd_min = BIN2BCD(min);
rtc->bcd_hr = BIN2BCD(hrs);
rtc->bcd_dom = BIN2BCD(day);
rtc->bcd_mth = BIN2BCD(mon);
rtc->bcd_year = BIN2BCD(yrs%100);
rtc->ctrl = 0;
local_irq_restore(flags);
return 0;
}
default:
return -EINVAL;
}
}
/*
* We enforce only one user at a time here with the open/close.
* Also clear the previous interrupt data on an open, and clean
* up things on a close.
*/
static int rtc_open(struct inode *inode, struct file *file)
{
if( !atomic_dec_and_test(&rtc_ready) )
{
atomic_inc( &rtc_ready );
return -EBUSY;
}
return 0;
}
static int rtc_release(struct inode *inode, struct file *file)
{
atomic_inc( &rtc_ready );
return 0;
}
/*
* The various file operations we support.
*/
static const struct file_operations rtc_fops = {
.ioctl = rtc_ioctl,
.open = rtc_open,
.release = rtc_release,
};
static struct miscdevice rtc_dev=
{
.minor = RTC_MINOR,
.name = "rtc",
.fops = &rtc_fops
};
static int __init rtc_MK48T08_init(void)
{
if (!MACH_IS_MVME16x)
return -ENODEV;
printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
return misc_register(&rtc_dev);
}
module_init(rtc_MK48T08_init);