linux-stable.git/drivers/rtc, branch v6.15.2

rtc: Fix offset calculation for .start_secs < 0

2025-06-10T11:17:09+00:00

commit fe9f5f96cfe8b82d0f24cbfa93718925560f4f8d upstream.

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: 989515647e783 ("rtc: Add one offset seconds to expand RTC range")
Signed-off-by: Alexandre Mergnat 
Reviewed-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-2-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman

rtc: Make rtc_time64_to_tm() support dates before 1970

2025-06-10T11:17:09+00:00

commit 7df4cfef8b351fec3156160bedfc7d6d29de4cce upstream.

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 
Reviewed-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-1-2b2f7e3f9349@baylibre.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

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 
Signed-off-by: Ingo Molnar

Merge tag 'rtc-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

2025-04-03T22:31:14+00:00

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
  ...

rtc: pcf85063: replace dev_err+return with return dev_err_probe

2025-04-01T10:01:53+00:00

Replace the dev_err plus return combo with return dev_err_probe() this
actually communicates the error type when it occurs and helps debugging
hardware issues.

Signed-off-by: Maud Spierings 
Link: https://lore.kernel.org/r/20250304-rtc_dev_err_probe-v1-1-9dcc042ad17e@gocontroll.com
Signed-off-by: Alexandre Belloni

rtc: pcf85063: do a SW reset if POR failed

2025-04-01T09:28:48+00:00

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 
Signed-off-by: Alexander Sverdlin 
Link: https://lore.kernel.org/r/20250120093451.30778-1-alexander.sverdlin@siemens.com
Signed-off-by: Alexandre Belloni

rtc: max31335: Add driver support for max31331

2025-03-31T22:17:01+00:00

MAX31331 is an ultra-low-power, I2C Real-Time Clock RTC.

Signed-off-by: PavithraUdayakumar-adi 
Link: https://lore.kernel.org/r/20250217-add_support_max31331_fix_8-v1-2-16ebcfc02336@analog.com
Signed-off-by: Alexandre Belloni

rtc: cros-ec: Avoid a couple of -Wflex-array-member-not-at-end warnings

2025-03-17T22:32:15+00:00

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:

drivers/rtc/rtc-cros-ec.c:62:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/rtc/rtc-cros-ec.c:40:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva 
Reviewed-by: Tzung-Bi Shih 
Link: https://lore.kernel.org/r/Z9PpPg06OK8ghNvm@kspp
Signed-off-by: Alexandre Belloni

rtc: rzn1: implement one-second accuracy for alarms

2025-03-17T22:25:58+00:00

The hardware alarm only supports one-minute accuracy which is coarse and
disables UIE usage. Use the 1-second interrupt to achieve per-second
accuracy. It is activated once we hit the per-minute alarm. The new
feature is optional. When there is no 1-second interrupt, old behaviour
with per-minute accuracy is used as before. With this feature, all tests
of 'rtctest' are successfully passed.

Signed-off-by: Wolfram Sang 
Link: https://lore.kernel.org/r/20250305101038.9933-2-wsa+renesas@sang-engineering.com
Signed-off-by: Alexandre Belloni

rtc: pcf50633: Remove

2025-03-17T21:55:37+00:00

The pcf50633 was used as part of the OpenMoko devices but
the support for its main chip was recently removed in:
commit 61b7f8920b17 ("ARM: s3c: remove all s3c24xx support")

See https://lore.kernel.org/all/Z8z236h4B5A6Ki3D@gallifrey/

Remove it.

Signed-off-by: Dr. David Alan Gilbert 
Link: https://lore.kernel.org/r/20250311014959.743322-3-linux@treblig.org
Signed-off-by: Alexandre Belloni