Add kernel/kernel and kernel/user locking for the periodic irq feature of
the rtc class.

PIE ioctls are also supported.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prevent the RTC driver from returning ENOIOCTLCMD to userspace.
Signed-off-by: NThomas Hommel <thomas.hommel@gefanuc.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus 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: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a goof in the revised classdev support for RTCs: make sure the /dev
node info is ready before the device is registered, not after.  Otherwise
the /sys/class/rtc/rtcN/dev attribute won't be created and then udev won't
have the information it needs to create the /dev/rtcN node.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Finish converting the RTC framework so it no longer uses class_device.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-By: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-By: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This simplifies the /dev support by removing a superfluous class_device (the
/sys/class/rtc-dev stuff) and the class_interface that hooks it into the rtc
core.  Accordingly, if it's configured then /dev support is now part of the
RTC core, and is never a separate module.

It's another step towards being able to remove "struct class_device".

[bunk@stusta.de: drivers/rtc/rtc-dev.c should #include "rtc-core.h"]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-By: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus 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: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix up for make allyesconfig.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Update RTC framework so that drivers can constify their method tables, moving
them from ".data" to ".rodata".  Then update the drivers.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: NOleg Verych <olecom@flower.upol.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If cdev_add() fails there is no good reason to call cdev_del().
Signed-off-by: NRolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Centralize CAP_SYS_XXX checks to avoid duplicate code and missing checks in
the drivers.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with
slight adjustments/refinements.  This makes UIE-less rtc drivers work
better with programs doing read/poll on /dev/rtc, such as hwclock.  This
emulation should not harm rtc drivers with UIE support, since
rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Appropriately use -ENOIOCTLCMD and -ENOTTY when the ioctl is not
implemented by a driver.

(akpm: we're not allowed to return -ENOIOCTLCMD to userspace.  This patch does
the right thing).
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make rtc-dev work well on 64-bit platforms with 32-bit userland.  On those
platforms, users might try to read 32-bit integer value.  This patch make
rtc-dev's read() work well for both "int" and "long" size.  This tweak is came
from genrtc driver.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add the dev interface to the RTC subsystem.

Each RTC will be available under /dev/rtcX .  A symlink from /dev/rtc0 to
/dev/rtc cab be obtained with the following udev rule:

KERNEL=="rtc0", SYMLINK+="rtc"
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>