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remarkable-linux/drivers/rtc/rtc-cmos.c
David Brownell 87ac84f42a rtc-cmos wakeup interface 
I finally got around to testing the updated wakeup event hooks for rtc-cmos,
and they follow in two patches:

 - Interface update ... when a simple enable_irq_wake() doesn't suffice,
   the platform data can hold suspend/resume callback hooks.

 - ACPI implementation ... provides callback hooks to do ACPI magic, and
   eliminate the legacy /proc/acpi/alarm file.

The interface update could go into 2.6.21, but that's not essential; they
will be NOPs on most PCs, without the ACPI stuff.

I suspect the ACPI folk may have opinions about how to merge that second
patch, and how to obsolete that legacy procfs file.  I'd like to see that
merge into 2.6.22 if possible...

As for how to kick it in ... two ways:

 - The appended "rtcwake" program; updated since the last time it was
   posted, it deals much better with timezones and DST.

 - Write the /sys/class/rtc/.../wakealarm file, then go to sleep.

For some reason RTC wake from "swsusp" stopped working on a system where
it previously worked; the alarm setting appears to get clobbered.  But
on the bright side, RTC wake from "standby" worked on a system that had
never been able to resume from that state before ... IDEACPI is my guess
as to why it finally started to work.  It's the old "two steps forward,
one step back" dance, I guess.

- Dave

/* gcc -Wall -Os -o rtcwake rtcwake.c */

#include <stdio.h>
#include <getopt.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>

#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>

#include <linux/rtc.h>

/* constants from legacy PC/AT hardware */
#define	RTC_PF	0x40
#define	RTC_AF	0x20
#define	RTC_UF	0x10

/*
 * rtcwake -- enter a system sleep state until specified wakeup time.
 *
 * This uses cross-platform Linux interfaces to enter a system sleep state,
 * and leave it no later than a specified time.  It uses any RTC framework
 * driver that supports standard driver model wakeup flags.
 *
 * This is normally used like the old "apmsleep" utility, to wake from a
 * suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM).  Most
 * platforms can implement those without analogues of BIOS, APM, or ACPI.
 *
 * On some systems, this can also be used like "nvram-wakeup", waking
 * from states like ACPI S4 (suspend to disk).  Not all systems have
 * persistent media that are appropriate for such suspend modes.
 *
 * The best way to set the system's RTC is so that it holds the current
 * time in UTC.  Use the "-l" flag to tell this program that the system
 * RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
 */

static char		*progname;

#ifdef	DEBUG
#define	VERSION	"1.0 dev (" __DATE__ " " __TIME__ ")"
#else
#define	VERSION	"0.9"
#endif

static unsigned		verbose;
static int		rtc_is_utc = -1;

static int may_wakeup(const char *devname)
{
	char	buf[128], *s;
	FILE	*f;

	snprintf(buf, sizeof buf, "/sys/class/rtc/%s/device/power/wakeup",
			devname);
	f = fopen(buf, "r");
	if (!f) {
		perror(buf);
		return 0;
	}
	fgets(buf, sizeof buf, f);
	fclose(f);

	s = strchr(buf, '\n');
	if (!s)
		return 0;
	*s = 0;

	/* wakeup events could be disabled or not supported */
	return strcmp(buf, "enabled") == 0;
}

/* all times should be in UTC */
static time_t	sys_time;
static time_t	rtc_time;

static int get_basetimes(int fd)
{
	struct tm	tm;
	struct rtc_time	rtc;

	/* this process works in RTC time, except when working
	 * with the system clock (which always uses UTC).
	 */
	if (rtc_is_utc)
		setenv("TZ", "UTC", 1);
	tzset();

	/* read rtc and system clocks "at the same time", or as
	 * precisely (+/- a second) as we can read them.
	 */
	if (ioctl(fd, RTC_RD_TIME, &rtc) < 0) {
		perror("read rtc time");
		return 0;
	}
	sys_time = time(0);
	if (sys_time == (time_t)-1) {
		perror("read system time");
		return 0;
	}

	/* convert rtc_time to normal arithmetic-friendly form,
	 * updating tm.tm_wday as used by asctime().
	 */
	memset(&tm, 0, sizeof tm);
	tm.tm_sec = rtc.tm_sec;
	tm.tm_min = rtc.tm_min;
	tm.tm_hour = rtc.tm_hour;
	tm.tm_mday = rtc.tm_mday;
	tm.tm_mon = rtc.tm_mon;
	tm.tm_year = rtc.tm_year;
	tm.tm_isdst = rtc.tm_isdst;	/* stays unspecified? */
	rtc_time = mktime(&tm);

	if (rtc_time == (time_t)-1) {
		perror("convert rtc time");
		return 0;
	}

	if (verbose) {
		if (!rtc_is_utc) {
			printf("\ttzone   = %ld\n", timezone);
			printf("\ttzname  = %s\n", tzname[daylight]);
			gmtime_r(&rtc_time, &tm);
		}
		printf("\tsystime = %ld, (UTC) %s",
				(long) sys_time, asctime(gmtime(&sys_time)));
		printf("\trtctime = %ld, (UTC) %s",
				(long) rtc_time, asctime(&tm));
	}

	return 1;
}

static int setup_alarm(int fd, time_t *wakeup)
{
	struct tm		*tm;
	struct rtc_wkalrm	wake;

	tm = gmtime(wakeup);

	wake.time.tm_sec = tm->tm_sec;
	wake.time.tm_min = tm->tm_min;
	wake.time.tm_hour = tm->tm_hour;
	wake.time.tm_mday = tm->tm_mday;
	wake.time.tm_mon = tm->tm_mon;
	wake.time.tm_year = tm->tm_year;
	wake.time.tm_wday = tm->tm_wday;
	wake.time.tm_yday = tm->tm_yday;
	wake.time.tm_isdst = tm->tm_isdst;

	/* many rtc alarms only support up to 24 hours from 'now' ... */
	if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
		if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) {
			perror("set rtc alarm");
			return 0;
		}
		if (ioctl(fd, RTC_AIE_ON, 0) < 0) {
			perror("enable rtc alarm");
			return 0;
		}

	/* ... so use the "more than 24 hours" request only if we must */
	} else {
		/* avoid an extra AIE_ON call */
		wake.enabled = 1;

		if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
			perror("set rtc wake alarm");
			return 0;
		}
	}

	return 1;
}

static void suspend_system(const char *suspend)
{
	FILE	*f = fopen("/sys/power/state", "w");

	if (!f) {
		perror("/sys/power/state");
		return;
	}

	fprintf(f, "%s\n", suspend);
	fflush(f);

	/* this executes after wake from suspend */
	fclose(f);
}

int main(int argc, char **argv)
{
	static char		*devname = "rtc0";
	static unsigned		seconds = 0;
	static char		*suspend = "standby";

	int		t;
	int		fd;
	time_t		alarm = 0;

	progname = strrchr(argv[0], '/');
	if (progname)
		progname++;
	else
		progname = argv[0];
	if (chdir("/dev/") < 0) {
		perror("chdir /dev");
		return 1;
	}

	while ((t = getopt(argc, argv, "d:lm:s:t:uVv")) != EOF) {
		switch (t) {

		case 'd':
			devname = optarg;
			break;

		case 'l':
			rtc_is_utc = 0;
			break;

		/* what system power mode to use?  for now handle only
		 * standardized mode names; eventually when systems define
		 * their own state names, parse /sys/power/state.
		 *
		 * "on" is used just to test the RTC alarm mechanism,
		 * bypassing all the wakeup-from-sleep infrastructure.
		 */
		case 'm':
			if (strcmp(optarg, "standby") == 0
					|| strcmp(optarg, "mem") == 0
					|| strcmp(optarg, "disk") == 0
					|| strcmp(optarg, "on") == 0
					) {
				suspend = optarg;
				break;
			}
			printf("%s: unrecognized suspend state '%s'\n",
					progname, optarg);
			goto usage;

		/* alarm time, seconds-to-sleep (relative) */
		case 's':
			t = atoi(optarg);
			if (t < 0) {
				printf("%s: illegal interval %s seconds\n",
						progname, optarg);
				goto usage;
			}
			seconds = t;
			break;

		/* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
		case 't':
			t = atoi(optarg);
			if (t < 0) {
				printf("%s: illegal time_t value %s\n",
						progname, optarg);
				goto usage;
			}
			alarm = t;
			break;

		case 'u':
			rtc_is_utc = 1;
			break;

		case 'v':
			verbose++;
			break;

		case 'V':
			printf("%s: version %s\n", progname, VERSION);
			break;

		default:
usage:
			printf("usage: %s [options]"
				"\n\t"
				"-d rtc0|rtc1|...\t(select rtc)"
				"\n\t"
				"-l\t\t\t(RTC uses local timezone)"
				"\n\t"
				"-m standby|mem|...\t(sleep mode)"
				"\n\t"
				"-s seconds\t\t(seconds to sleep)"
				"\n\t"
				"-t time_t\t\t(time to wake)"
				"\n\t"
				"-u\t\t\t(RTC uses UTC)"
				"\n\t"
				"-v\t\t\t(verbose messages)"
				"\n\t"
				"-V\t\t\t(show version)"
				"\n",
				progname);
			return 1;
		}
	}

	if (!alarm && !seconds) {
		printf("%s: must provide wake time\n", progname);
		goto usage;
	}

	/* REVISIT:  if /etc/adjtime exists, read it to see what
	 * the util-linux version of hwclock assumes.
	 */
	if (rtc_is_utc == -1) {
		printf("%s: assuming RTC uses UTC ...\n", progname);
		rtc_is_utc = 1;
	}

	/* this RTC must exist and (if we'll sleep) be wakeup-enabled */
	fd = open(devname, O_RDONLY);
	if (fd < 0) {
		perror(devname);
		return 1;
	}
	if (strcmp(suspend, "on") != 0 && !may_wakeup(devname)) {
		printf("%s: %s not enabled for wakeup events\n",
				progname, devname);
		return 1;
	}

	/* relative or absolute alarm time, normalized to time_t */
	if (!get_basetimes(fd))
		return 1;
	if (verbose)
		printf("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n",
				alarm, sys_time, rtc_time, seconds);
	if (alarm) {
		if (alarm < sys_time) {
			printf("%s: time doesn't go backward to %s",
					progname, ctime(&alarm));
			return 1;
		}
		alarm += sys_time - rtc_time;
	} else
		alarm = rtc_time + seconds + 1;
	if (setup_alarm(fd, &alarm) < 0)
		return 1;

	sync();
	printf("%s: wakeup from \"%s\" using %s at %s",
			progname, suspend, devname,
			ctime(&alarm));
	fflush(stdout);
	usleep(10 * 1000);

	if (strcmp(suspend, "on") != 0)
		suspend_system(suspend);
	else {
		unsigned long data;

		do {
			t = read(fd, &data, sizeof data);
			if (t < 0) {
				perror("rtc read");
				break;
			}
			if (verbose)
				printf("... %s: %03lx\n", devname, data);
		} while (!(data & RTC_AF));
	}

	if (ioctl(fd, RTC_AIE_OFF, 0) < 0)
		perror("disable rtc alarm interrupt");

	close(fd);
	return 0;
}

This patch:

Make rtc-cmos do the relevant magic so this RTC can wake the system from a
sleep state.  That magic comes in two basic flavors:

 - Straightforward:  enable_irq_wake(), the way it'd work on most SOC chips;
   or generally with system sleep states which don't disable core IRQ logic.

 - Roundabout, using non-IRQ platform hooks.  This is needed with ACPI and
   one almost-clone chip which uses a special wakeup-only alarm.  (That's
   the RTC used on Footbridge boards, FWIW, which don't do PM in Linux.)

A separate patch implements those hooks for ACPI platforms, so that rtc_cmos
can issue system wakeup events (and its sysfs "wakealarm" attribute works on
at least some systems).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:18 -07:00

759 lines
18 KiB
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Raw Blame History

/*
* RTC class driver for "CMOS RTC": PCs, ACPI, etc
*
* Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
* Copyright (C) 2006 David Brownell (convert to new framework)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/*
* The original "cmos clock" chip was an MC146818 chip, now obsolete.
* That defined the register interface now provided by all PCs, some
* non-PC systems, and incorporated into ACPI. Modern PC chipsets
* integrate an MC146818 clone in their southbridge, and boards use
* that instead of discrete clones like the DS12887 or M48T86. There
* are also clones that connect using the LPC bus.
*
* That register API is also used directly by various other drivers
* (notably for integrated NVRAM), infrastructure (x86 has code to
* bypass the RTC framework, directly reading the RTC during boot
* and updating minutes/seconds for systems using NTP synch) and
* utilities (like userspace 'hwclock', if no /dev node exists).
*
* So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
* interrupts disabled, holding the global rtc_lock, to exclude those
* other drivers and utilities on correctly configured systems.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
#include <asm-generic/rtc.h>
struct cmos_rtc {
struct rtc_device *rtc;
struct device *dev;
int irq;
struct resource *iomem;
void (*wake_on)(struct device *);
void (*wake_off)(struct device *);
u8 enabled_wake;
u8 suspend_ctrl;
/* newer hardware extends the original register set */
u8 day_alrm;
u8 mon_alrm;
u8 century;
};
/* both platform and pnp busses use negative numbers for invalid irqs */
#define is_valid_irq(n) ((n) >= 0)
static const char driver_name[] = "rtc_cmos";
/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
* always mask it against the irq enable bits in RTC_CONTROL. Bit values
* are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
*/
#define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
static inline int is_intr(u8 rtc_intr)
{
if (!(rtc_intr & RTC_IRQF))
return 0;
return rtc_intr & RTC_IRQMASK;
}
/*----------------------------------------------------------------*/
static int cmos_read_time(struct device *dev, struct rtc_time *t)
{
/* REVISIT: if the clock has a "century" register, use
* that instead of the heuristic in get_rtc_time().
* That'll make Y3K compatility (year > 2070) easy!
*/
get_rtc_time(t);
return 0;
}
static int cmos_set_time(struct device *dev, struct rtc_time *t)
{
/* REVISIT: set the "century" register if available
*
* NOTE: this ignores the issue whereby updating the seconds
* takes effect exactly 500ms after we write the register.
* (Also queueing and other delays before we get this far.)
*/
return set_rtc_time(t);
}
static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char rtc_control;
if (!is_valid_irq(cmos->irq))
return -EIO;
/* Basic alarms only support hour, minute, and seconds fields.
* Some also support day and month, for alarms up to a year in
* the future.
*/
t->time.tm_mday = -1;
t->time.tm_mon = -1;
spin_lock_irq(&rtc_lock);
t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
if (cmos->day_alrm) {
t->time.tm_mday = CMOS_READ(cmos->day_alrm);
if (!t->time.tm_mday)
t->time.tm_mday = -1;
if (cmos->mon_alrm) {
t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
if (!t->time.tm_mon)
t->time.tm_mon = -1;
}
}
rtc_control = CMOS_READ(RTC_CONTROL);
spin_unlock_irq(&rtc_lock);
/* REVISIT this assumes PC style usage: always BCD */
if (((unsigned)t->time.tm_sec) < 0x60)
t->time.tm_sec = BCD2BIN(t->time.tm_sec);
else
t->time.tm_sec = -1;
if (((unsigned)t->time.tm_min) < 0x60)
t->time.tm_min = BCD2BIN(t->time.tm_min);
else
t->time.tm_min = -1;
if (((unsigned)t->time.tm_hour) < 0x24)
t->time.tm_hour = BCD2BIN(t->time.tm_hour);
else
t->time.tm_hour = -1;
if (cmos->day_alrm) {
if (((unsigned)t->time.tm_mday) <= 0x31)
t->time.tm_mday = BCD2BIN(t->time.tm_mday);
else
t->time.tm_mday = -1;
if (cmos->mon_alrm) {
if (((unsigned)t->time.tm_mon) <= 0x12)
t->time.tm_mon = BCD2BIN(t->time.tm_mon) - 1;
else
t->time.tm_mon = -1;
}
}
t->time.tm_year = -1;
t->enabled = !!(rtc_control & RTC_AIE);
t->pending = 0;
return 0;
}
static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char mon, mday, hrs, min, sec;
unsigned char rtc_control, rtc_intr;
if (!is_valid_irq(cmos->irq))
return -EIO;
/* REVISIT this assumes PC style usage: always BCD */
/* Writing 0xff means "don't care" or "match all". */
mon = t->time.tm_mon;
mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
mon++;
mday = t->time.tm_mday;
mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
hrs = t->time.tm_hour;
hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;
min = t->time.tm_min;
min = (min < 60) ? BIN2BCD(min) : 0xff;
sec = t->time.tm_sec;
sec = (sec < 60) ? BIN2BCD(sec) : 0xff;
spin_lock_irq(&rtc_lock);
/* next rtc irq must not be from previous alarm setting */
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
/* update alarm */
CMOS_WRITE(hrs, RTC_HOURS_ALARM);
CMOS_WRITE(min, RTC_MINUTES_ALARM);
CMOS_WRITE(sec, RTC_SECONDS_ALARM);
/* the system may support an "enhanced" alarm */
if (cmos->day_alrm) {
CMOS_WRITE(mday, cmos->day_alrm);
if (cmos->mon_alrm)
CMOS_WRITE(mon, cmos->mon_alrm);
}
if (t->enabled) {
rtc_control |= RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
}
spin_unlock_irq(&rtc_lock);
return 0;
}
static int cmos_set_freq(struct device *dev, int freq)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
int f;
unsigned long flags;
if (!is_valid_irq(cmos->irq))
return -ENXIO;
/* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
f = ffs(freq);
if (f != 0) {
if (f-- > 16 || freq != (1 << f))
return -EINVAL;
f = 16 - f;
}
spin_lock_irqsave(&rtc_lock, flags);
CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
}
#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
static int
cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char rtc_control, rtc_intr;
unsigned long flags;
switch (cmd) {
case RTC_AIE_OFF:
case RTC_AIE_ON:
case RTC_UIE_OFF:
case RTC_UIE_ON:
case RTC_PIE_OFF:
case RTC_PIE_ON:
if (!is_valid_irq(cmos->irq))
return -EINVAL;
break;
default:
return -ENOIOCTLCMD;
}
spin_lock_irqsave(&rtc_lock, flags);
rtc_control = CMOS_READ(RTC_CONTROL);
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
rtc_control &= ~RTC_AIE;
break;
case RTC_AIE_ON: /* alarm on */
rtc_control |= RTC_AIE;
break;
case RTC_UIE_OFF: /* update off */
rtc_control &= ~RTC_UIE;
break;
case RTC_UIE_ON: /* update on */
rtc_control |= RTC_UIE;
break;
case RTC_PIE_OFF: /* periodic off */
rtc_control &= ~RTC_PIE;
break;
case RTC_PIE_ON: /* periodic on */
rtc_control |= RTC_PIE;
break;
}
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
}
#else
#define cmos_rtc_ioctl NULL
#endif
#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
static int cmos_procfs(struct device *dev, struct seq_file *seq)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char rtc_control, valid;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
valid = CMOS_READ(RTC_VALID);
spin_unlock_irq(&rtc_lock);
/* NOTE: at least ICH6 reports battery status using a different
* (non-RTC) bit; and SQWE is ignored on many current systems.
*/
return seq_printf(seq,
"periodic_IRQ\t: %s\n"
"update_IRQ\t: %s\n"
// "square_wave\t: %s\n"
// "BCD\t\t: %s\n"
"DST_enable\t: %s\n"
"periodic_freq\t: %d\n"
"batt_status\t: %s\n",
(rtc_control & RTC_PIE) ? "yes" : "no",
(rtc_control & RTC_UIE) ? "yes" : "no",
// (rtc_control & RTC_SQWE) ? "yes" : "no",
// (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
(rtc_control & RTC_DST_EN) ? "yes" : "no",
cmos->rtc->irq_freq,
(valid & RTC_VRT) ? "okay" : "dead");
}
#else
#define cmos_procfs NULL
#endif
static const struct rtc_class_ops cmos_rtc_ops = {
.ioctl = cmos_rtc_ioctl,
.read_time = cmos_read_time,
.set_time = cmos_set_time,
.read_alarm = cmos_read_alarm,
.set_alarm = cmos_set_alarm,
.proc = cmos_procfs,
.irq_set_freq = cmos_set_freq,
};
/*----------------------------------------------------------------*/
static struct cmos_rtc cmos_rtc;
static irqreturn_t cmos_interrupt(int irq, void *p)
{
u8 irqstat;
spin_lock(&rtc_lock);
irqstat = CMOS_READ(RTC_INTR_FLAGS);
irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
spin_unlock(&rtc_lock);
if (is_intr(irqstat)) {
rtc_update_irq(p, 1, irqstat);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
#ifdef CONFIG_PNPACPI
#define is_pnpacpi() 1
#define INITSECTION
#else
#define is_pnpacpi() 0
#define INITSECTION __init
#endif
static int INITSECTION
cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
{
struct cmos_rtc_board_info *info = dev->platform_data;
int retval = 0;
unsigned char rtc_control;
/* there can be only one ... */
if (cmos_rtc.dev)
return -EBUSY;
if (!ports)
return -ENODEV;
cmos_rtc.irq = rtc_irq;
cmos_rtc.iomem = ports;
/* For ACPI systems extension info comes from the FADT. On others,
* board specific setup provides it as appropriate. Systems where
* the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
* some almost-clones) can provide hooks to make that behave.
*/
if (info) {
cmos_rtc.day_alrm = info->rtc_day_alarm;
cmos_rtc.mon_alrm = info->rtc_mon_alarm;
cmos_rtc.century = info->rtc_century;
if (info->wake_on && info->wake_off) {
cmos_rtc.wake_on = info->wake_on;
cmos_rtc.wake_off = info->wake_off;
}
}
cmos_rtc.rtc = rtc_device_register(driver_name, dev,
&cmos_rtc_ops, THIS_MODULE);
if (IS_ERR(cmos_rtc.rtc))
return PTR_ERR(cmos_rtc.rtc);
cmos_rtc.dev = dev;
dev_set_drvdata(dev, &cmos_rtc);
/* platform and pnp busses handle resources incompatibly.
*
* REVISIT for non-x86 systems we may need to handle io memory
* resources: ioremap them, and request_mem_region().
*/
if (is_pnpacpi()) {
retval = request_resource(&ioport_resource, ports);
if (retval < 0) {
dev_dbg(dev, "i/o registers already in use\n");
goto cleanup0;
}
}
rename_region(ports, cmos_rtc.rtc->dev.bus_id);
spin_lock_irq(&rtc_lock);
/* force periodic irq to CMOS reset default of 1024Hz;
*
* REVISIT it's been reported that at least one x86_64 ALI mobo
* doesn't use 32KHz here ... for portability we might need to
* do something about other clock frequencies.
*/
CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
cmos_rtc.rtc->irq_freq = 1024;
/* disable irqs.
*
* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
* allegedly some older rtcs need that to handle irqs properly
*/
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
CMOS_WRITE(rtc_control, RTC_CONTROL);
CMOS_READ(RTC_INTR_FLAGS);
spin_unlock_irq(&rtc_lock);
/* FIXME teach the alarm code how to handle binary mode;
* <asm-generic/rtc.h> doesn't know 12-hour mode either.
*/
if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
dev_dbg(dev, "only 24-hr BCD mode supported\n");
retval = -ENXIO;
goto cleanup1;
}
if (is_valid_irq(rtc_irq))
retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
cmos_rtc.rtc->dev.bus_id,
cmos_rtc.rtc);
if (retval < 0) {
dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
goto cleanup1;
}
/* REVISIT optionally make 50 or 114 bytes NVRAM available,
* like rtc-ds1553, rtc-ds1742 ... this will often include
* registers for century, and day/month alarm.
*/
pr_info("%s: alarms up to one %s%s\n",
cmos_rtc.rtc->dev.bus_id,
is_valid_irq(rtc_irq)
? (cmos_rtc.mon_alrm
? "year"
: (cmos_rtc.day_alrm
? "month" : "day"))
: "no",
cmos_rtc.century ? ", y3k" : ""
);
return 0;
cleanup1:
rename_region(ports, NULL);
cleanup0:
rtc_device_unregister(cmos_rtc.rtc);
return retval;
}
static void cmos_do_shutdown(void)
{
unsigned char rtc_control;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
CMOS_WRITE(rtc_control, RTC_CONTROL);
CMOS_READ(RTC_INTR_FLAGS);
spin_unlock_irq(&rtc_lock);
}
static void __exit cmos_do_remove(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
cmos_do_shutdown();
if (is_pnpacpi())
release_resource(cmos->iomem);
rename_region(cmos->iomem, NULL);
if (is_valid_irq(cmos->irq))
free_irq(cmos->irq, cmos_rtc.rtc);
rtc_device_unregister(cmos_rtc.rtc);
cmos_rtc.dev = NULL;
dev_set_drvdata(dev, NULL);
}
#ifdef CONFIG_PM
static int cmos_suspend(struct device *dev, pm_message_t mesg)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
int do_wake = device_may_wakeup(dev);
unsigned char tmp;
/* only the alarm might be a wakeup event source */
spin_lock_irq(&rtc_lock);
cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
unsigned char irqstat;
if (do_wake)
tmp &= ~(RTC_PIE|RTC_UIE);
else
tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
CMOS_WRITE(tmp, RTC_CONTROL);
irqstat = CMOS_READ(RTC_INTR_FLAGS);
irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(irqstat))
rtc_update_irq(cmos->rtc, 1, irqstat);
}
spin_unlock_irq(&rtc_lock);
if (tmp & RTC_AIE) {
cmos->enabled_wake = 1;
if (cmos->wake_on)
cmos->wake_on(dev);
else
enable_irq_wake(cmos->irq);
}
pr_debug("%s: suspend%s, ctrl %02x\n",
cmos_rtc.rtc->dev.bus_id,
(tmp & RTC_AIE) ? ", alarm may wake" : "",
tmp);
return 0;
}
static int cmos_resume(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char tmp = cmos->suspend_ctrl;
/* re-enable any irqs previously active */
if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
if (cmos->enabled_wake) {
if (cmos->wake_off)
cmos->wake_off(dev);
else
disable_irq_wake(cmos->irq);
cmos->enabled_wake = 0;
}
spin_lock_irq(&rtc_lock);
CMOS_WRITE(tmp, RTC_CONTROL);
tmp = CMOS_READ(RTC_INTR_FLAGS);
tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(tmp))
rtc_update_irq(cmos->rtc, 1, tmp);
spin_unlock_irq(&rtc_lock);
}
pr_debug("%s: resume, ctrl %02x\n",
cmos_rtc.rtc->dev.bus_id,
cmos->suspend_ctrl);
return 0;
}
#else
#define cmos_suspend NULL
#define cmos_resume NULL
#endif
/*----------------------------------------------------------------*/
/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
* the device node will always be created as a PNPACPI device.
*/
#ifdef CONFIG_PNPACPI
#include <linux/pnp.h>
static int __devinit
cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
{
/* REVISIT paranoia argues for a shutdown notifier, since PNP
* drivers can't provide shutdown() methods to disable IRQs.
* Or better yet, fix PNP to allow those methods...
*/
return cmos_do_probe(&pnp->dev,
&pnp->res.port_resource[0],
pnp->res.irq_resource[0].start);
}
static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
{
cmos_do_remove(&pnp->dev);
}
#ifdef CONFIG_PM
static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
{
return cmos_suspend(&pnp->dev, mesg);
}
static int cmos_pnp_resume(struct pnp_dev *pnp)
{
return cmos_resume(&pnp->dev);
}
#else
#define cmos_pnp_suspend NULL
#define cmos_pnp_resume NULL
#endif
static const struct pnp_device_id rtc_ids[] = {
{ .id = "PNP0b00", },
{ .id = "PNP0b01", },
{ .id = "PNP0b02", },
{ },
};
MODULE_DEVICE_TABLE(pnp, rtc_ids);
static struct pnp_driver cmos_pnp_driver = {
.name = (char *) driver_name,
.id_table = rtc_ids,
.probe = cmos_pnp_probe,
.remove = __exit_p(cmos_pnp_remove),
/* flag ensures resume() gets called, and stops syslog spam */
.flags = PNP_DRIVER_RES_DO_NOT_CHANGE,
.suspend = cmos_pnp_suspend,
.resume = cmos_pnp_resume,
};
static int __init cmos_init(void)
{
return pnp_register_driver(&cmos_pnp_driver);
}
module_init(cmos_init);
static void __exit cmos_exit(void)
{
pnp_unregister_driver(&cmos_pnp_driver);
}
module_exit(cmos_exit);
#else /* no PNPACPI */
/*----------------------------------------------------------------*/
/* Platform setup should have set up an RTC device, when PNPACPI is
* unavailable ... this could happen even on (older) PCs.
*/
static int __init cmos_platform_probe(struct platform_device *pdev)
{
return cmos_do_probe(&pdev->dev,
platform_get_resource(pdev, IORESOURCE_IO, 0),
platform_get_irq(pdev, 0));
}
static int __exit cmos_platform_remove(struct platform_device *pdev)
{
cmos_do_remove(&pdev->dev);
return 0;
}
static void cmos_platform_shutdown(struct platform_device *pdev)
{
cmos_do_shutdown();
}
static struct platform_driver cmos_platform_driver = {
.remove = __exit_p(cmos_platform_remove),
.shutdown = cmos_platform_shutdown,
.driver = {
.name = (char *) driver_name,
.suspend = cmos_suspend,
.resume = cmos_resume,
}
};
static int __init cmos_init(void)
{
return platform_driver_probe(&cmos_platform_driver,
cmos_platform_probe);
}
module_init(cmos_init);
static void __exit cmos_exit(void)
{
platform_driver_unregister(&cmos_platform_driver);
}
module_exit(cmos_exit);
#endif /* !PNPACPI */
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
MODULE_LICENSE("GPL");
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