This adds a new "wakealarm" sysfs attribute to RTC class devices which support
alarm operations and are wakeup-capable:
- It reads as either empty, or the scheduled alarm time as seconds
since the POSIX epoch. (That time may already have passed, since
nothing currently enforces one-shot alarm semantics.)
- It can be written with an alarm time in the future, again seconds
since the POSIX epoch, which enables the alarm.
- It can be written with an alarm time not in the future (such as 0,
the start of the POSIX epoch) to disable the alarm.
Usage examples (some need GNU date) after "cd /sys/class/rtc/rtcN":
alarm after 10 minutes:
# echo $(( $(cat since_epoch) + 10 * 60 )) > wakealarm
alarm tuesday evening 10pm:
# date -d '10pm tuesday' "+%s" > wakealarm
disable alarm:
# echo 0 > wakealarm
This resembles the /proc/acpi/alarm file in that nothing happens when the
alarm triggers ... except possibly waking the system from sleep. It's also
like that in a nasty way: not much can be done to prevent one task from
clobbering another task's alarm settings.
It differs from that file in that there's no in-kernel date parser.
Note that a few RTCs ignore rtc_wkalrm.enabled when setting alarms, or aren't
set up correctly, so they won't yet behave with this attribute.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc_sysfs_add_device is needed even after dev initialization, so drop __devinit.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes some syslog spam as RTC drivers register; debug messages
shouldn't come out at "info" level.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's not clear how this thinko got through..
Cc: Olaf Hering <olaf@aepfle.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes RTC core components use "subsys_init" instead of "module_init", as
appropriate for subsystem infrastructure. This is mostly useful for
statically linking drivers in other parts of the tree that may provide an RTC
interface as a secondary functionality (e.g. part of a multifunction chip);
they won't need to worry so much about drivers/Makefile link order.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the sysfs interface to the RTC subsystem.
Each RTC client will have his own entry under /sys/classs/rtc/rtcN .
Within this entry some attributes are exported by the subsystem, like date and
time.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
