Commit d7278da5 authored by Tom Rini's avatar Tom Rini Committed by Linus Torvalds

[PATCH] A generic RTC driver [3/3]

This is part 3 of 3 of the genrtc patches.  This is my own slight bit
of work, as well as some work by Randolph Chung. This changes
set_rtc_time(struct *rtc_time) to return an int instead of void.
This was done so that the arch-specific code here could do additional
checks on the time and return an error if needed. This then introduces
include/asm-generic/rtc.h, include/asm-i386/rtc.h and
include/asm-alpha/rtc.h.  include/asm-generic/rtc.h contains the
get_rtc_time and set_rtc_time logic that is in drivers/char/rtc.c and
has been tested on SMP i386.  This also modifies include/asm-ppc/rtc.h
to return -ENODEV if no rtc hardware is present.

Additionally, Dave Jones pointed out to me a place where we might not be
safe when jiffies wraps, so this switches that to time_after().

From Randolph Chung, support for a 64bit kernel and a 32bit userland.
parent 23435fb5
...@@ -33,9 +33,10 @@ ...@@ -33,9 +33,10 @@
* 1.03 make it more portable zippel@linux-m68k.org * 1.03 make it more portable zippel@linux-m68k.org
* 1.04 removed useless timer code rz@linux-m68k.org * 1.04 removed useless timer code rz@linux-m68k.org
* 1.05 portable RTC_UIE emulation rz@linux-m68k.org * 1.05 portable RTC_UIE emulation rz@linux-m68k.org
* 1.06 set_rtc_time can return an error trini@kernel.crashing.org
*/ */
#define RTC_VERSION "1.05" #define RTC_VERSION "1.06"
#include <linux/module.h> #include <linux/module.h>
#include <linux/config.h> #include <linux/config.h>
...@@ -128,8 +129,8 @@ void gen_rtc_timer(unsigned long data) ...@@ -128,8 +129,8 @@ void gen_rtc_timer(unsigned long data)
lostint = get_rtc_ss() - oldsecs ; lostint = get_rtc_ss() - oldsecs ;
if (lostint<0) if (lostint<0)
lostint = 60 - lostint; lostint = 60 - lostint;
if (jiffies-tt_exp>1) if (time_after(jiffies, tt_exp))
printk("genrtc: timer task delayed by %ld jiffies\n", printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
jiffies-tt_exp); jiffies-tt_exp);
ttask_active=0; ttask_active=0;
stask_active=1; stask_active=1;
...@@ -174,7 +175,7 @@ static ssize_t gen_rtc_read(struct file *file, char *buf, ...@@ -174,7 +175,7 @@ static ssize_t gen_rtc_read(struct file *file, char *buf,
unsigned long data; unsigned long data;
ssize_t retval; ssize_t retval;
if (count < sizeof(unsigned long)) if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
return -EINVAL; return -EINVAL;
if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data) if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
...@@ -193,7 +194,14 @@ static ssize_t gen_rtc_read(struct file *file, char *buf, ...@@ -193,7 +194,14 @@ static ssize_t gen_rtc_read(struct file *file, char *buf,
schedule(); schedule();
} }
retval = put_user(data, (unsigned long *)buf); /* first test allows optimizer to nuke this case for 32-bit machines */
if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
unsigned int uidata = data;
retval = put_user(uidata, (unsigned long *)buf);
}
else {
retval = put_user(data, (unsigned long *)buf);
}
if (!retval) if (!retval)
retval = sizeof(unsigned long); retval = sizeof(unsigned long);
out: out:
...@@ -326,8 +334,7 @@ static int gen_rtc_ioctl(struct inode *inode, struct file *file, ...@@ -326,8 +334,7 @@ static int gen_rtc_ioctl(struct inode *inode, struct file *file,
wtime.tm_sec < 0 || wtime.tm_sec >= 60) wtime.tm_sec < 0 || wtime.tm_sec >= 60)
return -EINVAL; return -EINVAL;
set_rtc_time(&wtime); return set_rtc_time(&wtime);
return 0;
} }
} }
......
#ifndef _ALPHA_RTC_H
#define _ALPHA_RTC_H
/*
* Alpha uses the default access methods for the RTC.
*/
#include <asm-generic/rtc.h>
#endif
/*
* inclue/asm-generic/rtc.h
*
* Author: Tom Rini <trini@mvista.com>
*
* Based on:
* drivers/char/rtc.c
*
* Please read the COPYING file for all license details.
*/
#ifndef __ASM_RTC_H__
#define __ASM_RTC_H__
#ifdef __KERNEL__
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
#define RTC_PIE 0x40 /* periodic interrupt enable */
#define RTC_AIE 0x20 /* alarm interrupt enable */
#define RTC_UIE 0x10 /* update-finished interrupt enable */
extern void gen_rtc_interrupt(unsigned long);
/* some dummy definitions */
#define RTC_SQWE 0x08 /* enable square-wave output */
#define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
#define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
#define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
/*
* Returns true if a clock update is in progress
*/
static inline unsigned char rtc_is_updating(void)
{
unsigned char uip;
spin_lock_irq(&rtc_lock);
uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
spin_unlock_irq(&rtc_lock);
return uip;
}
static inline void get_rtc_time(struct rtc_time *time)
{
unsigned long uip_watchdog = jiffies;
unsigned char ctrl;
#ifdef CONFIG_DECSTATION
unsigned int real_year;
#endif
/*
* read RTC once any update in progress is done. The update
* can take just over 2ms. We wait 10 to 20ms. There is no need to
* to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
* If you need to know *exactly* when a second has started, enable
* periodic update complete interrupts, (via ioctl) and then
* immediately read /dev/rtc which will block until you get the IRQ.
* Once the read clears, read the RTC time (again via ioctl). Easy.
*/
if (rtc_is_updating() != 0)
while (jiffies - uip_watchdog < 2*HZ/100) {
barrier();
cpu_relax();
}
/*
* Only the values that we read from the RTC are set. We leave
* tm_wday, tm_yday and tm_isdst untouched. Even though the
* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
* by the RTC when initially set to a non-zero value.
*/
spin_lock_irq(&rtc_lock);
time->tm_sec = CMOS_READ(RTC_SECONDS);
time->tm_min = CMOS_READ(RTC_MINUTES);
time->tm_hour = CMOS_READ(RTC_HOURS);
time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
time->tm_mon = CMOS_READ(RTC_MONTH);
time->tm_year = CMOS_READ(RTC_YEAR);
#ifdef CONFIG_DECSTATION
real_year = CMOS_READ(RTC_DEC_YEAR);
#endif
ctrl = CMOS_READ(RTC_CONTROL);
spin_unlock_irq(&rtc_lock);
if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
{
BCD_TO_BIN(time->tm_sec);
BCD_TO_BIN(time->tm_min);
BCD_TO_BIN(time->tm_hour);
BCD_TO_BIN(time->tm_mday);
BCD_TO_BIN(time->tm_mon);
BCD_TO_BIN(time->tm_year);
}
#ifdef CONFIG_DECSTATION
time->tm_year += real_year - 72;
#endif
/*
* Account for differences between how the RTC uses the values
* and how they are defined in a struct rtc_time;
*/
if (time->tm_year <= 69)
time->tm_year += 100;
time->tm_mon--;
}
/* Set the current date and time in the real time clock. */
static inline int set_rtc_time(struct rtc_time *time)
{
unsigned char mon, day, hrs, min, sec;
unsigned char save_control, save_freq_select;
unsigned int yrs;
#ifdef CONFIG_DECSTATION
unsigned int real_yrs, leap_yr;
#endif
yrs = time->tm_year;
mon = time->tm_mon + 1; /* tm_mon starts at zero */
day = time->tm_mday;
hrs = time->tm_hour;
min = time->tm_min;
sec = time->tm_sec;
if (yrs > 255) /* They are unsigned */
return -EINVAL;
spin_lock_irq(&rtc_lock);
#ifdef CONFIG_DECSTATION
real_yrs = yrs;
leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
!((yrs + 1900) % 400));
yrs = 72;
/*
* We want to keep the year set to 73 until March
* for non-leap years, so that Feb, 29th is handled
* correctly.
*/
if (!leap_yr && mon < 3) {
real_yrs--;
yrs = 73;
}
#endif
/* These limits and adjustments are independant of
* whether the chip is in binary mode or not.
*/
if (yrs > 169) {
spin_unlock_irq(&rtc_lock);
return -EINVAL;
}
if (yrs >= 100)
yrs -= 100;
if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
|| RTC_ALWAYS_BCD) {
BIN_TO_BCD(sec);
BIN_TO_BCD(min);
BIN_TO_BCD(hrs);
BIN_TO_BCD(day);
BIN_TO_BCD(mon);
BIN_TO_BCD(yrs);
}
save_control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
#ifdef CONFIG_DECSTATION
CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
#endif
CMOS_WRITE(yrs, RTC_YEAR);
CMOS_WRITE(mon, RTC_MONTH);
CMOS_WRITE(day, RTC_DAY_OF_MONTH);
CMOS_WRITE(hrs, RTC_HOURS);
CMOS_WRITE(min, RTC_MINUTES);
CMOS_WRITE(sec, RTC_SECONDS);
CMOS_WRITE(save_control, RTC_CONTROL);
CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
spin_unlock_irq(&rtc_lock);
return 0;
}
static inline unsigned int get_rtc_ss(void)
{
struct rtc_time h;
get_rtc_time(&h);
return h.tm_sec;
}
static inline int get_rtc_pll(struct rtc_pll_info *pll)
{
return -EINVAL;
}
static inline int set_rtc_pll(struct rtc_pll_info *pll)
{
return -EINVAL;
}
#endif /* __KERNEL__ */
#endif /* __ASM_RTC_H__ */
#ifndef _I386_RTC_H
#define _I386_RTC_H
/*
* x86 uses the default access methods for the RTC.
*/
#include <asm-generic/rtc.h>
#endif
/*
* inclue/asm-parisc/rtc.h
*
* Copyright 2002 Randolph CHung <tausq@debian.org>
*
* Based on: include/asm-ppc/rtc.h and the genrtc driver in the
* 2.4 parisc linux tree
*/
#ifndef __ASM_RTC_H__
#define __ASM_RTC_H__
#ifdef __KERNEL__
#include <linux/rtc.h>
#include <asm/pdc.h>
#define SECS_PER_HOUR (60 * 60)
#define SECS_PER_DAY (SECS_PER_HOUR * 24)
#define RTC_PIE 0x40 /* periodic interrupt enable */
#define RTC_AIE 0x20 /* alarm interrupt enable */
#define RTC_UIE 0x10 /* update-finished interrupt enable */
extern void gen_rtc_interrupt(unsigned long);
/* some dummy definitions */
#define RTC_SQWE 0x08 /* enable square-wave output */
#define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
#define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
#define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
# define __isleap(year) \
((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
/* How many days come before each month (0-12). */
static const unsigned short int __mon_yday[2][13] =
{
/* Normal years. */
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
/* Leap years. */
{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
};
static int get_rtc_time(struct rtc_time *wtime)
{
struct pdc_tod tod_data;
long int days, rem, y;
const unsigned short int *ip;
if(pdc_tod_read(&tod_data) < 0)
return -1;
// most of the remainder of this function is:
// Copyright (C) 1991, 1993, 1997, 1998 Free Software Foundation, Inc.
// This was originally a part of the GNU C Library.
// It is distributed under the GPL, and was swiped from offtime.c
days = tod_data.tod_sec / SECS_PER_DAY;
rem = tod_data.tod_sec % SECS_PER_DAY;
wtime->tm_hour = rem / SECS_PER_HOUR;
rem %= SECS_PER_HOUR;
wtime->tm_min = rem / 60;
wtime->tm_sec = rem % 60;
y = 1970;
#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
while (days < 0 || days >= (__isleap (y) ? 366 : 365))
{
/* Guess a corrected year, assuming 365 days per year. */
long int yg = y + days / 365 - (days % 365 < 0);
/* Adjust DAYS and Y to match the guessed year. */
days -= ((yg - y) * 365
+ LEAPS_THRU_END_OF (yg - 1)
- LEAPS_THRU_END_OF (y - 1));
y = yg;
}
wtime->tm_year = y - 1900;
ip = __mon_yday[__isleap(y)];
for (y = 11; days < (long int) ip[y]; --y)
continue;
days -= ip[y];
wtime->tm_mon = y;
wtime->tm_mday = days + 1;
return 0;
}
static int set_rtc_time(struct rtc_time *wtime)
{
u_int32_t secs;
secs = mktime(wtime->tm_year + 1900, wtime->tm_mon + 1, wtime->tm_mday,
wtime->tm_hour, wtime->tm_min, wtime->tm_sec);
if(pdc_tod_set(secs, 0) < 0)
return -1;
else
return 0;
}
static inline unsigned int get_rtc_ss(void)
{
struct rtc_time h;
get_rtc_time(&h);
return h.tm_sec;
}
static inline int get_rtc_pll(struct rtc_pll_info *pll)
{
return -EINVAL;
}
static inline int set_rtc_pll(struct rtc_pll_info *pll)
{
return -EINVAL;
}
#endif /* __KERNEL__ */
#endif /* __ASM_RTC_H__ */
...@@ -68,7 +68,10 @@ static inline void set_rtc_time(struct rtc_time *time) ...@@ -68,7 +68,10 @@ static inline void set_rtc_time(struct rtc_time *time)
time->tm_sec); time->tm_sec);
(ppc_md.set_rtc_time)(nowtime); (ppc_md.set_rtc_time)(nowtime);
}
return 0;
} else
return -EINVAL;
} }
static inline unsigned int get_rtc_ss(void) static inline unsigned int get_rtc_ss(void)
......
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