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path: root/drivers/rtc/interface.c
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2008-07-04rtc: rtc_read_alarm() handles wraparoundDavid Brownell
While 0e36a9a4a788e4e92407774df76c545910810d35 ("rtc: fix readback from /sys/class/rtc/rtc?/wakealarm") made sure that active alarms were never returned with invalid "wildcard" fields (negative), it can still report (wrongly) that the alarm triggers in the past. Example, if it's now 10am, an alarm firing at 5am will be triggered TOMORROW not today. (Which may also be next month or next year...) This updates that alarm handling in three ways: * Handle alarm rollover in the common cases of RTCs that don't support matching on all date fields. * Skip the invalid-field logic when it's not needed. * Minor bugfix ... tm_isdst should be ignored, it's one of the fields Linux doesn't maintain. A warning is emitted for some of the unhandled rollover cases, but the possible combinations are a bit too numerous to handle every bit of potential hardware and firmware braindamage. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Mark Lord <lkml@rtr.ca> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-24rtc: use class iteration apiDave Young
Convert to use the class iteration api. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-12-05RTC: assure proper memory ordering with respect to RTC_DEV_BUSY flagJiri Kosina
We must make sure that the RTC_DEV_BUSY flag has proper lock semantics, i.e. that the RTC_DEV_BUSY stores clearing the flag don't get reordered before the preceeding stores and loads and vice versa. Spotted by Nick Piggin. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: David Brownell <david-b@pacbell.net> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29RTC: convert mutex to bitfieldJiri Kosina
RTC code is using mutex to assure exclusive access to /dev/rtc. This is however wrong usage, as it leaves the mutex locked when returning into userspace, which is unacceptable. Convert rtc->char_lock into bit operation. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16rtc: fix readback from /sys/class/rtc/rtc?/wakealarmMark Lord
Fix readback of RTC alarms on platforms which return -1 in non-hardware-supported RTC alarm fields. To fill in the missing (-1) values, we grab an RTC timestamp along with the RTC alarm value, and use the timestamp fields to populate the missing alarm fields. To counter field-wrap races (since the timestamp and alarm are not read together atomically), we read the RTC timestamp both before and after reading the RTC alarm value, and then check for wrapped fields --> if any have wrapped, we know we have a possible inconsistency, so we loop and reread the timestamp and alarm again. Wrapped fields in the RTC timestamps are an issue because rtc-cmos.c, for example, also gets/uses an RTC timestamp internally while fetching the RTC alarm. If our timestamp here wasn't the same (minutes and higher) as what was used internally there, then we might end up populating the -1 fields with inconsistent values. This fixes readbacks from /sys/class/rtc/rtc?/wakealarm, as well as other code paths which call rtc_read_alarm(). Signed-off-by: Mark Lord <mlord@pobox.com> Cc: David Brownell <david-b@pacbell.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16rtc_irq_set_freq() requires power-of-two and associated kerneldocDavid Brownell
RTC periodic IRQs are only defined to work for 2^N Hz values. This patch moves that validity check into the infrastructure, so drivers don't need to check it; and adds kerneldoc for the two interface functions related to periodic IRQs. (One of which was quite mysterious until its first use was recently checked in!) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16RTC: periodic irq fixAlessandro Zummo
Add kernel/kernel and kernel/user locking for the periodic irq feature of the rtc class. PIE ioctls are also supported. Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08rtc: remove "RTC_ALM_SET mode" bugsDavid Brownell
This fixes a common glitch in how RTC drivers handle two "set alarm" modes, by getting rid of the surprising/hidden one that was rarely implemented correctly (and which could expose nonportable hardware-specific behavior). The glitch comes from the /dev/rtcX logic implementing the legacy RTC_ALM_SET (limited to 24 hours, needing RTC_AIE_ON) ioctl on top of the RTC driver call providing access to the newer RTC_WKALM_SET (without those limitations) by initializing the day/month/year fields to be invalid ... that second mode. Now, since few RTC drivers check those fields, and most hardware misbehaves when faced with invalid date fields, many RTC drivers will set bogus alarm times on those RTC_ALM_SET code paths. (Several in-tree drivers have that issue, and I also noticed it with code reviews on several new RTC drivers.) This patch ensures that RTC drivers never see such invalid alarm fields, by moving some logic out of rtc-omap into the RTC_ALM_SET code and adding an explicit check (which will prevent the issue on other code paths). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Scott Wood <scottwood@freescale.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08rtc: remove rest of class_deviceDavid Brownell
Finish converting the RTC framework so it no longer uses class_device. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08rtc: rtc interfaces don't use class_deviceDavid Brownell
This patch removes class_device from the programming interface that the RTC framework exposes to the rest of the kernel. Now an rtc_device is passed, which is more type-safe and streamlines all the relevant code. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01[PATCH] rtc_cmos oops fixDavid Brownell
Fix an oops on the rtc_device_unregister() path by waiting until the last moment before nulling the rtc->ops vector. Fix some potential oopses by having the rtc_class_open()/rtc_class_close() interface increase the RTC's reference count while an RTC handle is available outside the RTC framework. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-11-25[PATCH] rtc class locking bugfixesDavid Brownell
I got a lockdep warning when running "rtctest" so I though it'd be good to see what was up. - The warning was for rtc->irq_task_lock, gotten from rtc_update_irq() by irq handlerss ... but in a handful of other cases, grabbed without blocking IRQs. - Some callers to rtc_update_irq() were not ensuring IRQs were blocked, yet the routine expects that; make sure all callers block IRQs. It would appear that RTC API tests haven't been part of anyone's kernel regression test suite recently, at least not with lockdep running. 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>
2006-11-25[PATCH] rtc framework handles periodic irqsDavid Brownell
The RTC framework has an irq_set_freq() method that should be used to manage the periodic IRQ frequency, but the current ioctl logic doesn't know how to do that. This patch teaches it how. This means that drivers implementing irq_set_freq() will automatically support RTC_IRQP_{READ,SET} ioctls; that logic doesn't need duplication within the driver. [akpm@osdl.org: export rtc_irq_set_freq] 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>
2006-06-25[PATCH] rtc subsystem, fix capability checks in kernel interfaceAlessandro Zummo
Remove commented capability checks and add some others. Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] RTC subsystem: classAlessandro Zummo
Add the basic RTC subsystem infrastructure to the kernel. rtc/class.c - registration facilities for RTC drivers rtc/interface.c - kernel/rtc interface functions rtc/hctosys.c - snippet of code that copies hw clock to sw clock at bootup, if configured to do so. 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>