Many RTCs have an on board non volatile storage. It can be battery backed
RAM or an EEPROM. Use the nvmem subsystem to export it to both userspace
and in-kernel consumers.
This stays compatible with the previous (non documented) ABI that was using
/sys/class/rtc/rtcx/device/nvram to export that memory. But will warn about
the deprecation.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Each text file under Documentation follows a different
format. Some doesn't even have titles!
Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:
- adjust identation of the titles;
- mark a table as such;
- don't capitalize chapter names.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
clock offset may be set and read in decimal parts per billion
attribute is /sys/class/rtc/rtcN/offset
The attribute is only visible for rtcs that have set_offset implemented.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This patch splits rtc.txt into two separate files, one for the
documentation itself, and the other for the rtctest.c file. The rtctest
file is moved into the kernel tools/testing/selftests/timers directory.
This will make automated testing easier. Note that the only difference in
the rtc.txt file is that the location of the rtctest.c file has changed.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: corbet@lwn.net
Cc: rtc-linux@googlegroups.com
Cc: linux-doc@vger.kernel.org
Cc: a.zummo@towertech.it
Cc: prarit@redhat.com
Cc: john.stultz@linaro.org
Cc: shuahkh@osg.samsung.com
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
This adds the ability for the rtc sysfs code to handle += characters at
the beginning of a wakealarm setting string. This will allow the user
to attempt to push out an existing wakealarm by a provided amount.
In the case that the += characters are provided but the alarm is not
active -EINVAL is returned.
his is useful, at least for my purposes in suspend/resume testing. The
basic test goes something like:
1. Set a wake alarm from userspace 5 seconds in the future
2. Start the suspend process (echo mem > /sys/power/state)
3. After ~2.5 seconds if userspace is still running (using another
thread to check this), move the wake alarm 5 more seconds
If the "move" involves an unset of the wakealarm then there's a period
of time where the system is midway through suspending but has no wake
alarm. It will get stuck.
We'd rather not remove the "move" since the idea is to avoid a cancelled
suspend when the alarm fires _during_ suspend. It is difficult for the
test to tell the difference between a suspend that was cancelled because
the alarm fired too early and a suspend that was
Signed-off-by: Bernie Thompson <bhthompson@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Doug Anderson <dianders@chromium.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To get time information via /proc/driver/rtc, only the first device (rtc0)
is used. If the rtcN (eg. rtc1 or rtc2) is used for the system clock,
there is no way to get information of rtcN via /proc/driver/rtc. With
this patch, the time data can be retrieved from the system clock RTC.
If the RTC_HCTOSYS_DEVICE is not defined, then rtc0 is used by default.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.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>
Now that the genric RTC layer handles much of the RTC functionality,
the rtc.txt documentation needs to be updated to remove outdated information.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
CONFIG_RTC_HCTOSYS allows the kernel to read the system time from the RTC
at boot and resume, avoiding the need for userspace to do so.
Unfortunately userspace currently has no way to know whether this
configuration option is enabled and thus cannot sensibly choose whether to
run hwclock itself or not. Add a hctosys sysfs attribute which indicates
whether a given RTC set the system clock.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
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>
The sysfs interface to the RTC class drivers is currently undocumented.
Add some basic documentation defining the semantics of the fields.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
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>
No functional changes here, just tighten up style/whitespace.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: 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>
Document the proper use of the irq_set_freq function.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: 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>
The max_user_freq member is not really meant for RTC drivers to modify, so
update the rtc documentation so drivers writers know what is expected of
them when handling periodic events.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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>
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>
Fix typo when describing RTC_WKALM. Add some helpful pointers to people
developing their own RTC driver. Change a bunch of the error messages in the
test program to be a bit more helpful.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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>
This updates the RTC documentation to summarize the two APIs now available:
the old PC/AT one, and the new RTC class drivers. It also updates the
included "rtctest.c" file to better meet Linux style guidelines, and to work
with the new RTC drivers.
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>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
