drivers/rtc/rtc-da9052.c: ALARM causes interrupt storm

Setting the alarm to a time not on a minute boundary results in repeated
interrupts being generated by the DA9052/3 PMIC device until the kernel
RTC core sees that the alarm has rung.  Sometimes the number and frequency
of interrupts can cause the kernel to disable the IRQ line used by the
DA9052/3 PMIC with disasterous consequences.  This patch fixes the
problem.

Even though the DA9052/3 PMIC is capable generating periodic interrupts,
ie TICKS, the method used to distinguish RTC_AF from RTC_PF events was
flawed and can not work in conjunction with the regmap_irq kernel core.
Thus that flawed detection has also been removed by the DA9052/3 PMIC RTC
driver's irq handler, so that it no longer reports the wrong type of event
to the kernel RTC core.

The internal static functions within the DA9052/3 PMIC RTC driver have
been changed to pass the 'da9052_rtc' structure instead of the 'da9052'
because there is no backwards pointer from the 'da9052' structure.

This patch fixes the three issues described above.  The first is serious
because usiing the RTC alarm set to a non minute boundary will eventually
cause all component drivers that depend on the interrupt line to fail.
The solution adopted is to round up to alarm time to the next highest
minute.

The second bug, reporting a RTC_PF event instead of an RTC_AF event turns
out to not matter with the current implementation of the kernel RTC core
as it seems to ignore the event type.  However, should that change in the
future it is better to fix the issue now and not have 'problems waiting to
happen'

The third set of changes are to make the da9052_rtc structure available to
all the local internal functions in the driver.  This was done during
testing so that diagnostic data could be stored there.  Should the
solution to the first issue be found not acceptable, then the alternative
of using the TICKS interrupt at the fixed one second interval in order to
step to the exact second of the requested alarm requires an extra (alarm
time) piece of data to be stored.  In devices that use the alarm function
to wake up from sleep, accuracy to the second will result in the device
being awake for up to nearly a minute longer than expected.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Cc: David Dajun Chen <dchen@diasemi.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>
rtc: rtc-ds1742: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-hym8563: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Heiko Stbner <heiko@sntech.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: isl12057: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-mv: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-palmas: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc: add support for maxim dallas rtc ds1343 and ds1344

Signed-off-by: Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: fix build error

Fix the following build errors reported by kbuild test robot by selecting
REGMAP_SPI in Kconfig file

drivers/built-in.o: In function `ds1343_probe':
rtc-ds1343.c:(.text+0x1baf8f): undefined reference to `devm_regmap_init_spi'

Signed-off-by: Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-ds1343.c: fix potential race condition

Avoid the potential race condition by avoiding bailing out of driver in
probe after registering with rtc subsystem

Also the set_alarm , read_alarm and alarm_irq_enable returns error if irq
registration fails in probe.

Also the sysfs will not create entry for alarm if irq registration fails
in probe.

Signed-off-by: Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
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>
drivers/rtc: add support for Microchip MCP795

Add driver for SPI RTC Microchip MCP795.  Only supports saving/loading
time from the chip (i.  e.  no alarms/power events/ID).

Signed-off-by: Josef Gajdusek <atx@atx.name>
Cc: Jingoo Han <jg1.han@samsung.com>
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>
rtc: da9063: RTC driver

Add the RTC driver for DA9063.

[akpm@linux-foundation.org: coding-style tweaks]
Signed-off-by: Opensource [Steve Twiss] <stwiss.opensource@diasemi.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Mark Brown <broonie@linaro.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David Dajun Chen <david.chen@diasemi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-omap.c: remove multiple device id checks

Remove multiple superfluous device id checks.  Since an id_table is
present in the driver probe() should never encounter an empty device id
entry.  In case of OF style match, of_match_device() returns an matching
entry.

For paranoia sake, check for device id entry once and fail probe() if none
is found.  This is much better than checking for it multiple times.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-omap.c: use BIT() macro

Use BIT() macro for RTC_HAS_<FEATURE> defines instead of hand-writing
bit masks.

Use BIT() macros for register bit field definitions.

While at it, fix indentation done using spaces.

No functional change in this patch.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-omap.c: add support for enabling 32khz clock

Newer versions of OMAP RTC IP such as those found in AM335x and DRA7x
need an explicit enable of 32khz functional clock which ticks the RTC.

AM335x support was working so far because of settings done in U-Boot.
However, the DRA7x U-Boot does no such enable of 32khz clock and this
patch is need to get the RTC to work on DRA7x at least.  In general, it
is better to not depend on settings done in U-Boot.

Thanks to Lokesh Vutla for noticing this.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-bfin.c: do not abort when requesting irq fails

The RTC framework does not let you return an error once a call to
devm_rtc_device_register has succeeded.  Avoid doing that when the IRQ
request fails as we can still support reading/writing the clock without
the IRQ.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Reported-by: Ales Novak <alnovak@suse.cz>
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>
drivers/rtc/rtc-hym8563.c: add optional clock-output-names property

This enables the setting of a custom clock name for the clock provided by
the hym8563 rtc.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-at91rm9200: fix infinite wait for ACKUPD irq

The rtc user must wait at least 1 sec between each time/calandar update
(see atmel's datasheet chapter "Updating Time/Calendar").

Use the 1Hz interrupt to update the at91_rtc_upd_rdy flag and wait for
the at91_rtc_wait_upd_rdy event if the rtc is not ready.

This patch fixes a deadlock in an uninterruptible wait when the RTC is
updated more than once every second.  AFAICT the bug is here from the
beginning, but I think we should at least backport this fix to 3.10 and
the following longterm and stable releases.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Bryan Evenson <bevenson@melinkcorp.com>
Tested-by: Bryan Evenson <bevenson@melinkcorp.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARM: at91: fix at91_sysirq_mask_rtc for sam9x5 SoCs

sam9x5 SoCs have the following errata:
 "RTC: Interrupt Mask Register cannot be used
  Interrupt Mask Register read always returns 0."

Hence we should not rely on what IMR claims about already masked IRQs
and just disable all IRQs.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Bryan Evenson <bevenson@melinkcorp.com>
Reviewed-by: Johan Hovold <johan@hovold.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Bryan Evenson <bevenson@melinkcorp.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mark Roszko <mark.roszko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-omap.c: enable RTC_IRQWAKEEN bits when Alarm is set

When RTC CLKTRCTRL bit is configured in HW_AUTO, module goes to sleep in
IDLE state.

The Alarm SWakeup event can be used to wakeup the RTC when it is in IDLE
state.  In order to do so, the alarm needs to be set and enabled before
RTC enters the IDLE state.  Also the wakeup generation for alarm/timer
event needs to be set (bits [1:0] in RTC_IRQWAKEEN register).

Currently RTC_IRQWAKEEN bits are set only in suspend/resume paths.  With
this ALARM interrupts are not generated when it enters IDLE state.  So
programming the RTC_IRQWAKEEN bits when ever ALARM is set.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.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>
drivers/rtc/rtc-sa1100.c: make of_device_id array const

Make of_device_id array const, because all OF functions handle
it as const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>