OpenCloudOS-Kernel/include/linux/mc146818rtc.h

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/* mc146818rtc.h - register definitions for the Real-Time-Clock / CMOS RAM
* Copyright Torsten Duwe <duwe@informatik.uni-erlangen.de> 1993
* derived from Data Sheet, Copyright Motorola 1984 (!).
* It was written to be part of the Linux operating system.
*/
/* permission is hereby granted to copy, modify and redistribute this code
* in terms of the GNU Library General Public License, Version 2 or later,
* at your option.
*/
#ifndef _MC146818RTC_H
#define _MC146818RTC_H
#include <asm/io.h>
#include <linux/rtc.h> /* get the user-level API */
#include <asm/mc146818rtc.h> /* register access macros */
#include <linux/bcd.h>
#include <linux/delay.h>
timekeeping: Ignore the bogus sleep time if pm_trace is enabled Power management suspend/resume tracing (ab)uses the RTC to store suspend/resume information persistently. As a consequence the RTC value is clobbered when timekeeping is resumed and tries to inject the sleep time. Commit a4f8f6667f09 ("timekeeping: Cap array access in timekeeping_debug") plugged a out of bounds array access in the timekeeping debug code which was caused by the clobbered RTC value, but we still use the clobbered RTC value for sleep time injection into kernel timekeeping, which will result in random adjustments depending on the stored "hash" value. To prevent this keep track of the RTC clobbering and ignore the invalid RTC timestamp at resume. If the system resumed successfully clear the flag, which marks the RTC as unusable, warn the user about the RTC clobber and recommend to adjust the RTC with 'ntpdate' or 'rdate'. [jstultz: Fixed up pr_warn formating, and implemented suggestions from Ingo] [ tglx: Rewrote changelog ] Originally-from: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Prarit Bhargava <prarit@redhat.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Xunlei Pang <xlpang@redhat.com> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/1480372524-15181-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-29 06:35:19 +08:00
#include <linux/pm-trace.h>
#ifdef __KERNEL__
#include <linux/spinlock.h> /* spinlock_t */
extern spinlock_t rtc_lock; /* serialize CMOS RAM access */
[PATCH] RTC framework driver for CMOS RTCs This is an "RTC framework" driver for the "CMOS" RTCs which are standard on PCs and some other platforms. That's MC146818 compatible silicon. Advantages of this vs. drivers/char/rtc.c (use one _or_ the other, only one will be able to claim the RTC irq) include: - This leverages both the new RTC framework and the driver model; both PNPACPI and platform device modes are supported. (A separate patch creates a platform device on PCs where PNPACPI isn't configured.) - It supports common extensions like longer alarms. (A separate patch exports that information from ACPI through platform_data.) - Likewise, system wakeup events use "real driver model support", with policy control via sysfs "wakeup" attributes and and using normal rtc ioctls to manage wakeup. (Patch in the works. The ACPI hooks are known; /proc/acpi/alarm can vanish. Making it work with EFI will be a minor challenge to someone with e.g. a MiniMac.) It's not yet been tested on non-x86 systems, without ACPI, or with HPET. And the RTC framework will surely have teething pains on "mainstream" PC-based systems (though must embedded Linux systems use it heavily), not limited to sorting out the "/dev/rtc0" issue (udev easily tweaked). Also, the ALSA rtctimer code doesn't use the new RTC API. Otherwise, this should be a no-known-regressions replacement for the old drivers/char/rtc.c driver, and should help the non-embedded distros (and the new timekeeping code) start to switch to the framework. Note also that any systems using "rtc-m48t86" are candidates to switch over to this more functional driver; the platform data is different, and the way bytes are read is different, but otherwise those chips should be compatible. [akpm@osdl.org: sparc32 fix] [akpm@osdl.org: sparc64 fix] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Woody Suwalski <woodys@xandros.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:02 +08:00
/* Some RTCs extend the mc146818 register set to support alarms of more
* than 24 hours in the future; or dates that include a century code.
* This platform_data structure can pass this information to the driver.
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 15:34:00 +08:00
*
* Also, some platforms need suspend()/resume() hooks to kick in special
* handling of wake alarms, e.g. activating ACPI BIOS hooks or setting up
* a separate wakeup alarm used by some almost-clone chips.
[PATCH] RTC framework driver for CMOS RTCs This is an "RTC framework" driver for the "CMOS" RTCs which are standard on PCs and some other platforms. That's MC146818 compatible silicon. Advantages of this vs. drivers/char/rtc.c (use one _or_ the other, only one will be able to claim the RTC irq) include: - This leverages both the new RTC framework and the driver model; both PNPACPI and platform device modes are supported. (A separate patch creates a platform device on PCs where PNPACPI isn't configured.) - It supports common extensions like longer alarms. (A separate patch exports that information from ACPI through platform_data.) - Likewise, system wakeup events use "real driver model support", with policy control via sysfs "wakeup" attributes and and using normal rtc ioctls to manage wakeup. (Patch in the works. The ACPI hooks are known; /proc/acpi/alarm can vanish. Making it work with EFI will be a minor challenge to someone with e.g. a MiniMac.) It's not yet been tested on non-x86 systems, without ACPI, or with HPET. And the RTC framework will surely have teething pains on "mainstream" PC-based systems (though must embedded Linux systems use it heavily), not limited to sorting out the "/dev/rtc0" issue (udev easily tweaked). Also, the ALSA rtctimer code doesn't use the new RTC API. Otherwise, this should be a no-known-regressions replacement for the old drivers/char/rtc.c driver, and should help the non-embedded distros (and the new timekeeping code) start to switch to the framework. Note also that any systems using "rtc-m48t86" are candidates to switch over to this more functional driver; the platform data is different, and the way bytes are read is different, but otherwise those chips should be compatible. [akpm@osdl.org: sparc32 fix] [akpm@osdl.org: sparc64 fix] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Woody Suwalski <woodys@xandros.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:02 +08:00
*/
struct cmos_rtc_board_info {
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 15:34:00 +08:00
void (*wake_on)(struct device *dev);
void (*wake_off)(struct device *dev);
drivers/rtc/rtc-cmos.c: drivers/char/rtc.c features for DECstation support This brings in drivers/char/rtc.c functionality required for DECstation and, should the maintainers decide to switch, Alpha systems to use rtc-cmos. Specifically these features are made available: * RTC iomem rather than x86/PCI port I/O mapping, controlled with the RTC_IOMAPPED macro as with the original driver. The DS1287A chip in all DECstation systems is mapped in the host bus address space as a contiguous block of 64 32-bit words of which the least significant byte accesses the RTC chip for both reads and writes. All the address and data window register accesses are made transparently by the chipset glue logic so that the device appears directly mapped on the host bus. * A way to set the size of the address space explicitly with the newly-added `address_space' member of the platform part of the RTC device structure. This avoids the unreliable heuristics that does not work in a setup where the RTC is not explicitly accessed with the usual address and data window register pair. * The ability to use the RTC periodic interrupt as a system clock device, which is implemented by arch/mips/kernel/cevt-ds1287.c for DECstation systems and takes the RTC interrupt away from the RTC driver. Eventually hooking back to the clock device's interrupt handler should be possible for the purpose of the alarm clock and possibly also update-in-progress interrupt, but this is not done by this change. o To avoid interfering with the clock interrupt all the places where the RTC interrupt mask is fiddled with are only executed if and IRQ has been assigned to the RTC driver. o To avoid changing the clock setup Register A is not fiddled with if CMOS_RTC_FLAGS_NOFREQ is set in the newly-added `flags' member of the platform part of the RTC device structure. Originally, in drivers/char/rtc.c, this was keyed with the absence of the RTC interrupt, just like the interrupt mask, but there only the periodic interrupt frequency is set, whereas rtc-cmos also sets the divider bits. Therefore a new flag is introduced so that systems where the RTC interrupt is not usable rather than used as a system clock device can fully initialise the RTC. * A small clean-up is made to the IRQ assignment code that makes the IRQ number hardcoded to -1 rather than arbitrary -ENXIO (or whatever error happens to be returned by platform_get_irq) where no IRQ has been assigned to the RTC driver (NO_IRQ might be another candidate, but it looks like this macro has inconsistent or missing definitions and limited use and might therefore be unsafe). Verified to work correctly with a DECstation 5000/240 system. [akpm@linux-foundation.org: fix weird code layout] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-07 05:35:49 +08:00
u32 flags;
#define CMOS_RTC_FLAGS_NOFREQ (1 << 0)
int address_space;
[PATCH] RTC framework driver for CMOS RTCs This is an "RTC framework" driver for the "CMOS" RTCs which are standard on PCs and some other platforms. That's MC146818 compatible silicon. Advantages of this vs. drivers/char/rtc.c (use one _or_ the other, only one will be able to claim the RTC irq) include: - This leverages both the new RTC framework and the driver model; both PNPACPI and platform device modes are supported. (A separate patch creates a platform device on PCs where PNPACPI isn't configured.) - It supports common extensions like longer alarms. (A separate patch exports that information from ACPI through platform_data.) - Likewise, system wakeup events use "real driver model support", with policy control via sysfs "wakeup" attributes and and using normal rtc ioctls to manage wakeup. (Patch in the works. The ACPI hooks are known; /proc/acpi/alarm can vanish. Making it work with EFI will be a minor challenge to someone with e.g. a MiniMac.) It's not yet been tested on non-x86 systems, without ACPI, or with HPET. And the RTC framework will surely have teething pains on "mainstream" PC-based systems (though must embedded Linux systems use it heavily), not limited to sorting out the "/dev/rtc0" issue (udev easily tweaked). Also, the ALSA rtctimer code doesn't use the new RTC API. Otherwise, this should be a no-known-regressions replacement for the old drivers/char/rtc.c driver, and should help the non-embedded distros (and the new timekeeping code) start to switch to the framework. Note also that any systems using "rtc-m48t86" are candidates to switch over to this more functional driver; the platform data is different, and the way bytes are read is different, but otherwise those chips should be compatible. [akpm@osdl.org: sparc32 fix] [akpm@osdl.org: sparc64 fix] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Woody Suwalski <woodys@xandros.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:02 +08:00
u8 rtc_day_alarm; /* zero, or register index */
u8 rtc_mon_alarm; /* zero, or register index */
u8 rtc_century; /* zero, or register index */
};
#endif
/**********************************************************************
* register summary
**********************************************************************/
#define RTC_SECONDS 0
#define RTC_SECONDS_ALARM 1
#define RTC_MINUTES 2
#define RTC_MINUTES_ALARM 3
#define RTC_HOURS 4
#define RTC_HOURS_ALARM 5
/* RTC_*_alarm is always true if 2 MSBs are set */
# define RTC_ALARM_DONT_CARE 0xC0
#define RTC_DAY_OF_WEEK 6
#define RTC_DAY_OF_MONTH 7
#define RTC_MONTH 8
#define RTC_YEAR 9
/* control registers - Moto names
*/
#define RTC_REG_A 10
#define RTC_REG_B 11
#define RTC_REG_C 12
#define RTC_REG_D 13
/**********************************************************************
* register details
**********************************************************************/
#define RTC_FREQ_SELECT RTC_REG_A
/* update-in-progress - set to "1" 244 microsecs before RTC goes off the bus,
* reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
* totalling to a max high interval of 2.228 ms.
*/
# define RTC_UIP 0x80
# define RTC_DIV_CTL 0x70
/* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
# define RTC_REF_CLCK_4MHZ 0x00
# define RTC_REF_CLCK_1MHZ 0x10
# define RTC_REF_CLCK_32KHZ 0x20
/* 2 values for divider stage reset, others for "testing purposes only" */
# define RTC_DIV_RESET1 0x60
# define RTC_DIV_RESET2 0x70
rtc: mc146818-lib: Fix the AltCentury for AMD platforms Setting the century forward has been failing on AMD platforms. There was a previous attempt at fixing this for family 0x17 as part of commit 7ad295d5196a ("rtc: Fix the AltCentury value on AMD/Hygon platform") but this was later reverted due to some problems reported that appeared to stem from an FW bug on a family 0x17 desktop system. The same comments mentioned in the previous commit continue to apply to the newer platforms as well. ``` MC146818 driver use function mc146818_set_time() to set register RTC_FREQ_SELECT(RTC_REG_A)'s bit4-bit6 field which means divider stage reset value on Intel platform to 0x7. While AMD/Hygon RTC_REG_A(0Ah)'s bit4 is defined as DV0 [Reference]: DV0 = 0 selects Bank 0, DV0 = 1 selects Bank 1. Bit5-bit6 is defined as reserved. DV0 is set to 1, it will select Bank 1, which will disable AltCentury register(0x32) access. As UEFI pass acpi_gbl_FADT.century 0x32 (AltCentury), the CMOS write will be failed on code: CMOS_WRITE(century, acpi_gbl_FADT.century). Correct RTC_REG_A bank select bit(DV0) to 0 on AMD/Hygon CPUs, it will enable AltCentury(0x32) register writing and finally setup century as expected. ``` However in closer examination the change previously submitted was also modifying bits 5 & 6 which are declared reserved in the AMD documentation. So instead modify just the DV0 bank selection bit. Being cognizant that there was a failure reported before, split the code change out to a static function that can also be used for exclusions if any regressions such as Mikhail's pop up again. Cc: Jinke Fan <fanjinke@hygon.cn> Cc: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Link: https://lore.kernel.org/all/CABXGCsMLob0DC25JS8wwAYydnDoHBSoMh2_YLPfqm3TTvDE-Zw@mail.gmail.com/ Link: https://www.amd.com/system/files/TechDocs/51192_Bolton_FCH_RRG.pdf Signed-off-by: Raul E Rangel <rrangel@chromium.org> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20220111225750.1699-1-mario.limonciello@amd.com
2022-01-12 06:57:50 +08:00
/* In AMD BKDG bit 5 and 6 are reserved, bit 4 is for select dv0 bank */
# define RTC_AMD_BANK_SELECT 0x10
/* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
# define RTC_RATE_SELECT 0x0F
/**********************************************************************/
#define RTC_CONTROL RTC_REG_B
# define RTC_SET 0x80 /* disable updates for clock setting */
# define RTC_PIE 0x40 /* periodic interrupt enable */
# define RTC_AIE 0x20 /* alarm interrupt enable */
# define RTC_UIE 0x10 /* update-finished interrupt enable */
# 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 RTC_INTR_FLAGS RTC_REG_C
/* caution - cleared by read */
# define RTC_IRQF 0x80 /* any of the following 3 is active */
# define RTC_PF 0x40
# define RTC_AF 0x20
# define RTC_UF 0x10
/**********************************************************************/
#define RTC_VALID RTC_REG_D
# define RTC_VRT 0x80 /* valid RAM and time */
/**********************************************************************/
#ifndef ARCH_RTC_LOCATION /* Override by <asm/mc146818rtc.h>? */
#define RTC_IO_EXTENT 0x8
#define RTC_IO_EXTENT_USED 0x2
#define RTC_IOMAPPED 1 /* Default to I/O mapping. */
#else
#define RTC_IO_EXTENT_USED RTC_IO_EXTENT
#endif /* ARCH_RTC_LOCATION */
rtc: mc146818-lib: fix RTC presence check To prevent an infinite loop in mc146818_get_time(), commit 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs") added a check for RTC availability. Together with a later fix, it checked if bit 6 in register 0x0d is cleared. This, however, caused a false negative on a motherboard with an AMD SB710 southbridge; according to the specification [1], bit 6 of register 0x0d of this chipset is a scratchbit. This caused a regression in Linux 5.11 - the RTC was determined broken by the kernel and not used by rtc-cmos.c [3]. This problem was also reported in Fedora [4]. As a better alternative, check whether the UIP ("Update-in-progress") bit is set for longer then 10ms. If that is the case, then apparently the RTC is either absent (and all register reads return 0xff) or broken. Also limit the number of loop iterations in mc146818_get_time() to 10 to prevent an infinite loop there. The functions mc146818_get_time() and mc146818_does_rtc_work() will be refactored later in this patch series, in order to fix a separate problem with reading / setting the RTC alarm time. This is done so to avoid a confusion about what is being fixed when. In a previous approach to this problem, I implemented a check whether the RTC_HOURS register contains a value <= 24. This, however, sometimes did not work correctly on my Intel Kaby Lake laptop. According to Intel's documentation [2], "the time and date RAM locations (0-9) are disconnected from the external bus" during the update cycle so reading this register without checking the UIP bit is incorrect. [1] AMD SB700/710/750 Register Reference Guide, page 308, https://developer.amd.com/wordpress/media/2012/10/43009_sb7xx_rrg_pub_1.00.pdf [2] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet Volume 1 of 2, page 209 Intel's Document Number: 334658-006, https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf [3] Functions in arch/x86/kernel/rtc.c apparently were using it. [4] https://bugzilla.redhat.com/show_bug.cgi?id=1936688 Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs") Fixes: ebb22a059436 ("rtc: mc146818: Dont test for bit 0-5 in Register D") Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-5-mat.jonczyk@o2.pl
2021-12-11 04:01:26 +08:00
bool mc146818_does_rtc_work(void);
int mc146818_get_time(struct rtc_time *time);
int mc146818_set_time(struct rtc_time *time);
bool mc146818_avoid_UIP(void (*callback)(unsigned char seconds, void *param),
void *param);
#endif /* _MC146818RTC_H */