Requesting a threaded interrupt without a primary handler and without
IRQF_ONESHOT is dangerous, and after commit 1c6c6952 ("genirq: Reject
bogus threaded irq requests"), these requests are rejected.  This causes
->probe() to fail, and the RTC driver not to be availble.

To fix, add IRQF_ONESHOT to the IRQ flags.

Tested on OMAP3730/OveroSTORM and OMAP4430/Panda board using rtcwake to
wake from system suspend multiple times.
Signed-off-by: NKevin Hilman <khilman@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

RTC stores time and date in several registers.  Due to the fact that
these registers can't be read instantaneously, there is a chance that
reading from counting registers gives an error of one minute, one hour,
one day, etc.

To address this issue, the RTC has hardware support to copy the RTC
counting registers to static shadowed registers.  The current
implementation does not use this feature, and in a stress test, we can
reproduce this error at a rate of around two times per 300000 readings.

Fix the implementation to ensure that the right snapshot of time is
captured.
Signed-off-by: NKonstantin Shlyakhovoy <x0155534@ti.com>
Signed-off-by: NNishanth Menon <nm@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: linux-omap <linux-omap@vger.kernel.org>
Acked-by: NMykola Oleksiienko <x0174904@ti.com>
Acked-by: NOleksandr Dmytryshyn <oleksandr.dmytryshyn@ti.com>
Acked-by: NGraeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Following changes are made as part of this change:

1. As TWL RTC supports periodic interrupt, the correct event should be
   RTC_PF instead of RTC_UF.

2. No need to initialize variable "events" to 0 & then OR it with the
   event values.  Hence fixing it.
Signed-off-by: NVenu Byravarasu <vbyravarasu@nvidia.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>

For clearing RTC interrupt, programming ALARM bit only is sufficient, as
all other bits are any way not affected by writing 0 to them.

Hence removed unwanted OR operation.
Signed-off-by: NVenu Byravarasu <vbyravarasu@nvidia.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>

As part of probe, before enabling RTC, RTC_CTRL register is read to check
if it is already running.  If RTC is used by kernel alone, then this read
is not required.  Even if RTC was enabled already by boot loader, setting
STOP_RTC bit again should not harm.  Hence removed unwanted read
operation.
Signed-off-by: NVenu Byravarasu <vbyravarasu@nvidia.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>

As the TWL RTC driver has a cached copy of enabled RTC interrupt bits in
variable rtc_irq_bits, that can be checked before really setting or
masking any of the interrupt bits.
Signed-off-by: NVenu Byravarasu <vbyravarasu@nvidia.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>

Add the DT support for the TI rtc-twl present in the twl4030 and twl6030
devices.
Signed-off-by: NBenoit Cousson <b-cousson@ti.com>
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>

Only register as an RTC device after the hardware has been
successfully initialized.  The RTC class driver will call
back to this driver to read a pending alarm, and other
drivers watching for new devices on the RTC class may
read the RTC time upon registration.  Such access might
occur while the RTC is stopped, prior to clearing
pending alarms, etc.

The new ordering also avoids leaving the platform
device drvdata set to an unregistered struct rtc_device *
on probe errors.
Signed-off-by: NTodd Poynor <toddpoynor@google.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Now that the irq is properly threaded (due to it needing i2c access)
we should also remove the local_irq_enable() call in twl_rtc_interrupt.
Testing this with Pandaboard, the RTC is still working.

[Reworked commit message -jstultz]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The driver is accessing to i2c bus in interrupt handler.
Therefore, it should use threaded irq.
Signed-off-by: NIlkka Koskinen <ilkka.koskinen@nokia.com>
Acked-by: NBalaji T K <balajitk@ti.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

We forget to save the return value of the call to
twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG); in 'ret', making the
test of 'ret < 0' dead code since 'ret' then couldn't possibly have
changed since the last test just a few lines above.  It also makes us not
detect failures from that specific twl_rtc_write_u8() call.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Rusev <source@mvista.com>
Cc: "George G. Davis" <gdavis@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the generic code handles UIE mode irqs via periodic
alarm interrupts, no one calls the
rtc_class_ops->update_irq_enable() method anymore.

This patch removes the driver hooks and implementations of
update_irq_enable if no one else is calling it.

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: NJohn Stultz <john.stultz@linaro.org>

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning of
the declaration specifiers in a declaration is an obsolescent feature.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-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 adds support for RTC in phoenix TWL6030.
Register offset addresses have changed in TWL6030
rtc-twl.c will hence forth support all twl RTC (4030, 5030, 6030 ..)
Signed-off-by: NBalaji T K <balajitk@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This patch renames all twl4030_ functions to twl_ so that RTC driver can be
shared between Triton and Phoenix.
Signed-off-by: NBalaji T K <balajitk@ti.com>
Signed-off-by: NNayak Rajendra <rnayak@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This patch renames function names like twl4030_i2c_write_u8,
twl4030_i2c_read_u8 to twl_i2c_write_u8, twl_i2c_read_u8
and also common variable in twl-core.c
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NBalaji T K <balajitk@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The upcoming TWL6030 is companion chip for OMAP4 like the current TWL4030
for OMAP3. The common modules like RTC, Regulator creates opportunity
to re-use the most of the code from twl4030.

This patch renames few common drivers twl4030* files to twl* to enable
the code re-use.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NBalaji T K <balajitk@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This patch enables the alarm interrupt of TWL4030 RTC to wake up the
system from suspend. You can test this patch with following command.

# echo +10 > /sys/class/rtc/rtc0/wakealarm; echo mem > /sys/power/state;
Signed-off-by: NKim Kyuwon <q1.kim@samsung.com>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Cc: Kyungmin Park <kyungmin.park@samsung.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>

Cc: a.zummo@towertech.it
Cc: rtc-linux@googlegroups.com
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

A triggering RTC alarm should be able to power on a device that has been
powered off. This patch enables that on twl4030 by not masking the alarm
interrupt at shutdown.
Signed-off-by: NMatti Halme <matti.halme@nokia.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Samuel Ortiz <sameo@openedhand.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- implement alarm_irq_enable
- return correct error code when registering fails

[dbrownell@users.sourceforge.net: build fixes, force 1/sec irqs]
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: rtc-linux@googlegroups.com
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes a bunch of irq checking misuses.  Most drivers were
getting irq via platform_get_irq(), which returns -ENXIO or r->start.

rtc-cmos.c is special.  It is using PNP and platform bindings.  Hopefully
nobody is using PNP IRQ 0 for RTC.  So the changes should be safe.

rtc-sh.c is using platform_get_irq, but was storing a result into an
unsigned type, then was checking for < 0.  This is fixed now.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix build error when RTC_INTF_DEV=n:

drivers/rtc/rtc-twl4030.c:402: error: 'twl4030_rtc_ioctl' undeclared here (not in a function)
make[3]: *** [drivers/rtc/rtc-twl4030.o] Error 1
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Samuel Ortiz <sameo@openedhand.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a driver for the RTC inside the TWL4030 multi-function device.
It's a fairly basic RTC, with a wake-capable alarm.

Note that many of the pre-release Overo boards now in circulation can't
effectively use this RTC, because of a wiring error that puts its TWL
chip into "secure" mode.  (As in "secure yourself against tampering".)
This isn't an issue on other OMAP3 boards now supported in mainline,
such as Beagle and Labrador.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>