linux-toradex.git/drivers/rtc/interface.c, branch v2.6.26-rc1

rtc: use class iteration api

2008-01-25T04:40:44+00:00

Convert to use the class iteration api.

Signed-off-by: Dave Young 
Cc: Alessandro Zummo 
Signed-off-by: Greg Kroah-Hartman

RTC: assure proper memory ordering with respect to RTC_DEV_BUSY flag

2007-12-05T17:21:18+00:00

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 
Cc: Nick Piggin 
Cc: David Brownell 
Acked-by: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

RTC: convert mutex to bitfield

2007-11-29T17:24:54+00:00

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 
Acked-by: Alessandro Zummo 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: fix readback from /sys/class/rtc/rtc?/wakealarm

2007-10-16T16:43:13+00:00

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 
Cc: David Brownell 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc_irq_set_freq() requires power-of-two and associated kerneldoc

2007-10-16T16:43:13+00:00

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 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

RTC: periodic irq fix

2007-10-16T16:43:13+00:00

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 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: remove "RTC_ALM_SET mode" bugs

2007-05-08T18:15:19+00:00

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 
Cc: Scott Wood 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: remove rest of class_device

2007-05-08T18:15:18+00:00

Finish converting the RTC framework so it no longer uses class_device.

Signed-off-by: David Brownell 
Acked-by: Greg Kroah-Hartman 
Acked-By: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: rtc interfaces don't use class_device

2007-05-08T18:15:18+00:00

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 
Acked-by: Greg Kroah-Hartman 
Acked-By: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] rtc_cmos oops fix

2007-03-01T22:53:37+00:00

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 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds