cmos_interrupt() can be called in a non-interrupt context, such as in
an ACPI event handler (which runs in an interrupt thread). Therefore,
usage of spin_lock(&rtc_lock) is insecure. Use spin_lock_irqsave() /
spin_unlock_irqrestore() instead.
Before a misguided
commit 6950d046eb ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
the cmos_interrupt() function used spin_lock_irqsave(). That commit
changed it to spin_lock() and broke locking, which was partially fixed in
commit 13be2efc39 ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
That second commit did not take account of the ACPI fixed event handler
pathway, however. It introduced local_irq_disable() workarounds in
cmos_check_wkalrm(), which can cause problems on PREEMPT_RT kernels
and are now unnecessary.
Add an explicit comment so that this change will not be reverted by
mistake.
Cc: stable@vger.kernel.org
Fixes: 6950d046eb ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Closes: https://lore.kernel.org/all/aDtJ92foPUYmGheF@debian.local/
Link: https://lore.kernel.org/r/20250607210608.14835-1-mat.jonczyk@o2.pl
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Instead of the open-coded read/modify/write sequence, we can simply use
the regmap helpers regmap_set_bits() and regmap_update_bits()
respectively.
This makes the code easier to read, and avoids extra work in case the
underlying bus supports updating bits via
struct regmap_bus::reg_update_bits() directly (which is the case for
S2MPG10 on gs101 where this driver communicates via ACPM).
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250409-s2mpg10-v4-31-d66d5f39b6bf@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Add support for Samsung's S2MPG10 PMIC RTC, which is similar to the
existing PMIC RTCs supported by this driver.
S2MPG10 doesn't use I2C, so we expect the core driver to have created a
regmap for us.
Additionally, it can be used for doing a cold-reset. If requested to do
so (via DT), S2MPG10 is programmed with a watchdog configuration that
will perform a full power cycle upon watchdog expiry.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250409-s2mpg10-v4-27-d66d5f39b6bf@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The Samsung S2MPG10 PMIC is not connected via I2C as this driver
assumes, hence this driver's current approach of creating an I2C-based
regmap doesn't work for it, and this driver should use the regmap
provided by the parent (core) driver instead for that PMIC.
To prepare this driver for s2mpg support, restructure the code to only
create a regmap if one isn't provided by the parent.
No functional changes, since the parent doesn't provide a regmap for
any of the PMICs currently supported by this driver. Having this change
separate will simply make the addition of S2MPG10 support more
self-contained, without additional restructuring.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250409-s2mpg10-v4-26-d66d5f39b6bf@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
While the RTC framework intends to only handle dates after 1970 for
consumers, time conversion must also work for earlier dates to cover
e.g. storing dates beyond an RTC's range_max. This is most relevant for
the rtc-mt6397 driver that has
range_min = RTC_TIMESTAMP_BEGIN_1900;
range_max = mktime64(2027, 12, 31, 23, 59, 59);
and so needs working support for timestamps in 1900 starting in less than
three years.
So shift the tested interval of timestamps to also cover years 1900 to
1970.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-5-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This is easier to handle because you can just consult date(1) to convert
between a seconds-since-1970 value and a date string:
$ date --utc -d @3661
Thu Jan 1 01:01:01 AM UTC 1970
$ date -d "Jan 1 12:00:00 AM UTC 1900" +%s
-2208988800
The intended side effect is that this prepares the test for dates before
1970. The division of a negative value by 86400 doesn't result in the
desired days-since-1970 value as e.g. secs=-82739 should map to days=-1.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-3-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The comparison
rtc->start_secs > rtc->range_max
has a signed left-hand side and an unsigned right-hand side.
So the comparison might become true for negative start_secs which is
interpreted as a (possibly very large) positive value.
As a negative value can never be bigger than an unsigned value
the correct representation of the (mathematical) comparison
rtc->start_secs > rtc->range_max
in C is:
rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max
Use that to fix the offset calculation currently used in the
rtc-mt6397 driver.
Fixes: 989515647e ("rtc: Add one offset seconds to expand RTC range")
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-2-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Conversion of dates before 1970 is still relevant today because these
dates are reused on some hardwares to store dates bigger than the
maximal date that is representable in the device's native format.
This prominently and very soon affects the hardware covered by the
rtc-mt6397 driver that can only natively store dates in the interval
1900-01-01 up to 2027-12-31. So to store the date 2028-01-01 00:00:00
to such a device, rtc_time64_to_tm() must do the right thing for
time=-2208988800.
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-1-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
When the regmap framework was introduced to this driver,
the PCF8563_REG_AMN register within the set_alarm function was
incorrectly changed to PCF8563_REG_SC.
The PCF8563_REG_SC register is the seconds register.
This caused alarm values to be written to the seconds register
when an alarm was set. Which means the alarm would not trigger
as expected and the seconds register would be overwritten
with an incorrect value.
Signed-off-by: Troy Mitchell <troymitchell988@gmail.com>
Link: https://lore.kernel.org/r/20250531-pcf8563-fix-alarm-v2-1-cac4b1716167@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The driver currently uses dev_err for messages that have a very low probability
of being read by the user as the error will probably never happen and the
systems with the RTC probably don't have any user able to read the message.
Moreover, the only user action after getting this message is the restart the
action so drop the level to dev_dbg.
Link: https://lore.kernel.org/r/20250525222153.1472917-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
When an application sets and enables an alarm on Loongson RTC devices,
the alarm notification fails to propagate to userspace because the
ACPI event handler omits calling rtc_update_irq().
As a result, processes waiting via select() or poll() on RTC device
files fail to receive alarm notifications.
The ACPI interrupt is also triggered multiple times. In loongson_rtc_handler,
we need to clear TOY_MATCH0_REG to resolve this issue.
Fixes: 09471d8f5b ("rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr()")
Fixes: 1b733a9ebc ("rtc: Add rtc driver for the Loongson family chips")
Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://lore.kernel.org/r/20250509084416.7979-1-liudalin@kylinsec.com.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
On many Qualcomm platforms the PMIC RTC control and time registers are
read-only so that the RTC time can not be updated. Instead an offset
needs be stored in some machine-specific non-volatile memory, which a
driver can take into account.
On platforms where the offset is stored in a Qualcomm specific UEFI
variable the variables are also accessed in a non-standard way, which
means that the OS cannot assume that the variable service is available
by the time the driver probes.
Use the new 'qcom,uefi-rtc-info' property to determine whether to probe
defer until the UEFI offset becomes available so that the offset can be
used also when the RTC driver is built in or when a dependency of the
UEFI variable driver is built as a module (e.g. the driver for the SCM
interconnects).
Fixes: bba38b8748 ("rtc: pm8xxx: add support for uefi offset")
Reported-by: Rob Clark <robdclark@gmail.com>
Link: https://lore.kernel.org/lkml/CAF6AEGsfke=x0p1b2-uNX6DuQfRyEjVbJaxTbVLDT2YvSkGJbg@mail.gmail.com/
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250423075143.11157-3-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The DT bindings for this driver define the interrupts in the order as
they are numbered in the interrupt controller. The old platform_data,
however, listed them in a different order. So, for DT based platforms,
they are mixed up. Assign them specifically for DT, so we can keep the
bindings stable. After the fix, 'rtctest' passes again on the Renesas
Genmai board (RZ-A1 / R7S72100).
Fixes: dab5aec64b ("rtc: sh: add support for rza series")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20250227134256.9167-11-wsa+renesas@sang-engineering.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RTC updates from Alexandre Belloni:
"We see a net reduction of the number of lines of code thanks to the
removal of a now unused driver and a testing tool that is not used
anymore. Apart from this, the max31335 driver gets support for a new
part number and pm8xxx gets UEFI support.
Core:
- setdate is removed as it has better replacements
- skip alarms with a second resolution when we know the RTC doesn't
support those.
Subsystem:
- remove unnecessary private struct members
- use devm_pm_set_wake_irq were relevant
Drivers:
- ds1307: stop disabling alarms on probe for DS1337, DS1339, DS1341
and DS3231
- max31335: add max31331 support
- pcf50633 is removed as support for the related SoC has been removed
- pcf85063: properly handle POR failures"
* tag 'rtc-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (50 commits)
rtc: remove 'setdate' test program
selftest: rtc: skip some tests if the alarm only supports minutes
rtc: mt6397: drop unused defines
rtc: pcf85063: replace dev_err+return with return dev_err_probe
rtc: pcf85063: do a SW reset if POR failed
rtc: max31335: Add driver support for max31331
dt-bindings: rtc: max31335: Add max31331 support
rtc: cros-ec: Avoid a couple of -Wflex-array-member-not-at-end warnings
dt-bindings: rtc: pcf2127: Reference spi-peripheral-props.yaml
rtc: rzn1: implement one-second accuracy for alarms
rtc: pcf50633: Remove
rtc: pm8xxx: implement qcom,no-alarm flag for non-HLOS owned alarm
rtc: pm8xxx: mitigate flash wear
rtc: pm8xxx: add support for uefi offset
dt-bindings: rtc: qcom-pm8xxx: document qcom,no-alarm flag
rtc: rv3032: drop WADA
rtc: rv3032: fix EERD location
rtc: pm8xxx: switch to devm_device_init_wakeup
rtc: pm8xxx: fix possible race condition
rtc: mpfs: switch to devm_device_init_wakeup
...
Power-on Reset has a documented issue in PCF85063, refer to its datasheet,
section "Software reset":
"There is a low probability that some devices will have corruption of the
registers after the automatic power-on reset if the device is powered up
with a residual VDD level. It is required that the VDD starts at zero volts
at power up or upon power cycling to ensure that there is no corruption of
the registers. If this is not possible, a reset must be initiated after
power-up (i.e. when power is stable) with the software reset command"
Trigger SW reset if there is an indication that POR has failed.
Link: https://www.nxp.com/docs/en/data-sheet/PCF85063A.pdf
Signed-off-by: Lukas Stockmann <lukas.stockmann@siemens.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20250120093451.30778-1-alexander.sverdlin@siemens.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
