linux-stable.git/drivers/rtc/Kconfig, branch linux-5.4.y

rtc: Improve performance of rtc_time64_to_tm(). Add tests.

2025-06-27T10:02:58+00:00

commit 1d1bb12a8b1805ddeef9793ebeb920179fb0fa38 upstream.

The current implementation of rtc_time64_to_tm() contains unnecessary
loops, branches and look-up tables. The new one uses an arithmetic-based
algorithm appeared in [1] and is approximately 4.3 times faster (YMMV).

The drawback is that the new code isn't intuitive and contains many 'magic
numbers' (not unusual for this type of algorithm). However, [1] justifies
all those numbers and, given this function's history, the code is unlikely
to need much maintenance, if any at all.

Add a KUnit test case that checks every day in a 160,000 years interval
starting on 1970-01-01 against the expected result. Add a new config
RTC_LIB_KUNIT_TEST symbol to give the option to run this test suite.

[1] Neri, Schneider, "Euclidean Affine Functions and Applications to
Calendar Algorithms". https://arxiv.org/abs/2102.06959

Signed-off-by: Cassio Neri 
Reported-by: kernel test robot 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210624201343.85441-1-cassio.neri@gmail.com
Signed-off-by: Uwe Kleine-KÃ¶nig 
Signed-off-by: Greg Kroah-Hartman

rtc: mt6397: select IRQ_DOMAIN instead of depending on it

2024-03-26T22:22:24+00:00

[ Upstream commit 544c42f798e1651dcb04fb0395219bf0f1c2607e ]

IRQ_DOMAIN is a hidden (not user visible) symbol. Users cannot set
it directly thru "make *config", so drivers should select it instead
of depending on it if they need it.
Relying on it being set for a dependency is risky.

Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.

Therefore, change the use of "depends on" for IRQ_DOMAIN to
"select" for RTC_DRV_MT6397.

Fixes: 04d3ba70a3c9 ("rtc: mt6397: add IRQ domain dependency")
Cc: Arnd Bergmann 
Cc: Eddie Huang 
Cc: Sean Wang 
Cc: Matthias Brugger 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Cc: Alessandro Zummo 
Cc: Alexandre Belloni 
Cc: linux-rtc@vger.kernel.org
Cc: Marc Zyngier 
Cc: Philipp Zabel 
Cc: Peter Rosin 
Reviewed-by: AngeloGioacchino Del Regno 
Signed-off-by: Randy Dunlap 
Link: https://lore.kernel.org/r/20240213050258.6167-1-rdunlap@infradead.org
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: rx8010: select REGMAP_I2C

2021-09-26T12:07:14+00:00

[ Upstream commit 0c45d3e24ef3d3d87c5e0077b8f38d1372af7176 ]

The rtc-rx8010 uses the I2C regmap but doesn't select it in Kconfig so
depending on the configuration the build may fail. Fix it.

Signed-off-by: Yu-Tung Chang 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210830052532.40356-1-mtwget@gmail.com
Signed-off-by: Sasha Levin

rtc: s5m: select REGMAP_I2C

2021-03-04T09:26:29+00:00

[ Upstream commit 1f0cbda3b452b520c5f3794f8f0e410e8bc7386a ]

The rtc-s5m uses the I2C regmap but doesn't select it in Kconfig so
depending on the configuration the build may fail. Fix it.

Fixes: 959df7778bbd ("rtc: Enable compile testing for Maxim and Samsung drivers")
Signed-off-by: Bartosz Golaszewski 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210114102219.23682-2-brgl@bgdev.pl
Signed-off-by: Sasha Levin

rtc: max8907: add missing select REGMAP_IRQ

2020-03-25T07:25:56+00:00

commit 5d892919fdd0cefd361697472d4e1b174a594991 upstream.

I have hit the following build error:

  armv7a-hardfloat-linux-gnueabi-ld: drivers/rtc/rtc-max8907.o: in function `max8907_rtc_probe':
  rtc-max8907.c:(.text+0x400): undefined reference to `regmap_irq_get_virq'

max8907 should select REGMAP_IRQ

Fixes: 94c01ab6d7544 ("rtc: add MAX8907 RTC driver")
Cc: stable 
Signed-off-by: Corentin Labbe 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

rtc: Kconfig: select REGMAP_I2C when necessary

2020-02-24T07:37:03+00:00

[ Upstream commit 578c2b661e2b1b474ea3571a3c3c6d57bae89e8d ]

Some i2c RTC drivers are using regmap but are not selecting REGMAP_I2C
which may lead to build failures.

Link: https://lore.kernel.org/r/20200127221724.10160-2-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: i2c/spi: Avoid inclusion of REGMAP support when not needed

2020-02-24T07:36:31+00:00

[ Upstream commit 34719de919af07682861cb0fa2bcf64da33ecf44 ]

Merely enabling I2C and RTC selects REGMAP_I2C and REGMAP_SPI, even when
no driver needs it.  While the former can be moduler, the latter cannot,
and thus becomes built-in.

Fix this by moving the select statements for REGMAP_I2C and REGMAP_SPI
from the RTC_I2C_AND_SPI helper to the individual drivers that depend on
it.

Note that the comment for RTC_I2C_AND_SPI refers to SND_SOC_I2C_AND_SPI
for more information, but the latter does not select REGMAP_{I2C,SPI}
itself, and defers that to the individual drivers, too.

Fixes: 080481f54ef62121 ("rtc: merge ds3232 and ds3234")
Signed-off-by: Geert Uytterhoeven 
Reported-by: kbuild test robot 
Reported-by: kbuild test robot 
Link: https://lore.kernel.org/r/20200112171349.22268-1-geert@linux-m68k.org
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

Merge tag 'rtc-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

2019-09-22T18:05:43+00:00

Pull RTC updates from Alexandre Belloni:
 "Two new drivers and the new pcf2127 feature make the bulk of the
  additions. The rest are the usual fixes and new features.

  Subsystem:
   - add debug message when registration fails

  New drivers:
   - Amlogic Virtual Wake
   - Freescale FlexTimer Module alarm

  Drivers:
   - remove superfluous error messages
   - convert to i2c_new_dummy_device and devm_i2c_new_dummy_device
   - Remove dev_err() usage after platform_get_irq()
   - Set RTC range for: pcf2123, pcf8563, snvs.
   - pcf2127: tamper detection and watchdog support
   - pcf85363: fix regmap issue
   - sun6i: H6 support
   - remove w90x900/nuc900 driver"

* tag 'rtc-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (51 commits)
  rtc: meson: mark PM functions as __maybe_unused
  rtc: sc27xx: Remove clearing SPRD_RTC_POWEROFF_ALM_FLAG flag
  dt-bindings: rtc: ds1307: add rx8130 compatible
  rtc: sun6i: Allow using as wakeup source from suspend
  rtc: pcf8563: let the core handle range offsetting
  rtc: pcf8563: remove useless indirection
  rtc: pcf8563: convert to devm_rtc_allocate_device
  rtc: pcf8563: add Microcrystal RV8564 compatible
  rtc: pcf8563: add Epson RTC8564 compatible
  rtc: s35390a: convert to devm_i2c_new_dummy_device()
  rtc: max77686: convert to devm_i2c_new_dummy_device()
  rtc: pcf85363/pcf85263: fix regmap error in set_time
  rtc: snvs: switch to rtc_time64_to_tm/rtc_tm_to_time64
  rtc: snvs: set range
  rtc: snvs: fix possible race condition
  rtc: pcf2127: bugfix: watchdog build dependency
  rtc: pcf2127: add tamper detection support
  rtc: pcf2127: add watchdog feature support
  rtc: pcf2127: bugfix: read rtc disables watchdog
  rtc: pcf2127: cleanup register and bit defines
  ...

mfd / platform: cros_ec: Move cros-ec core driver out from MFD

2019-09-02T10:33:12+00:00

Now, the ChromeOS EC core driver has nothing related to an MFD device, so
move that driver from the MFD subsystem to the platform/chrome subsystem.

Signed-off-by: Enric Balletbo i Serra 
Acked-by: Andy Shevchenko 
Acked-by: Thierry Reding 
Acked-by: Mark Brown 
Acked-by: Wolfram Sang 
Acked-by: Neil Armstrong 
Acked-by: Alexandre Belloni 
Acked-by: Jonathan Cameron 
Acked-by: Benjamin Tissoires 
Acked-by: Dmitry Torokhov 
Acked-by: Sebastian Reichel 
Acked-by: Chanwoo Choi 
Reviewed-by: Gwendal Grignou 
Tested-by: Gwendal Grignou 
Signed-off-by: Lee Jones

rtc: pcf2127: bugfix: watchdog build dependency

2019-08-27T16:24:15+00:00

Disable watchdog registation when kernel is build without
watchdog functionality, and enable watchdog core otherwise.
This removes compile errors like the one below:

drivers/rtc/rtc-pcf2127.o: in function `pcf2127_probe.constprop.3':
rtc-pcf2127.c:(.text.unlikely+0x2c8): undefined reference to
`devm_watchdog_register_device'

Watchdog feature in chip will always be configured as
this is safe to do in both cases and minimize code churn.

Reported-by: Hulk Robot 
Reported-by: YueHaibing 
Fixes: bbc597561ce1 ("rtc: pcf2127: add watchdog feature support")
Signed-off-by: Bruno Thomsen 
Link: https://lore.kernel.org/r/20190827143656.4734-1-bruno.thomsen@gmail.com
Signed-off-by: Alexandre Belloni