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Meagan Lloyd 523923cfd5 rtc: ds1307: handle oscillator stop flag (OSF) for ds1341
In using CONFIG_RTC_HCTOSYS, rtc_hctosys() will sync the RTC time to the
kernel time as long as rtc_read_time() succeeds. In some power loss
situations, our supercapacitor-backed DS1342 RTC comes up with either an
unpredictable future time or the default 01/01/00 from the datasheet.
The oscillator stop flag (OSF) is set in these scenarios due to the
power loss and can be used to determine the validity of the RTC data.

This change expands the oscillator stop flag (OSF) handling that has
already been implemented for some chips to the ds1341 chip (DS1341 and
DS1342 share a datasheet). This handling manages the validity of the RTC
data in .read_time and .set_time based on the OSF.

Signed-off-by: Meagan Lloyd <meaganlloyd@linux.microsoft.com>
Reviewed-by: Tyler Hicks <code@tyhicks.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/1749665656-30108-3-git-send-email-meaganlloyd@linux.microsoft.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2025-07-23 23:24:38 +02:00
arch The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
block treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto EFI updates for v6.16 2025-05-30 12:42:57 -07:00
Documentation dt-bindings: rtc: pcf85063: add binding for RV8063 2025-07-23 18:52:08 +02:00
drivers rtc: ds1307: handle oscillator stop flag (OSF) for ds1341 2025-07-23 23:24:38 +02:00
fs The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
include The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
init Rust changes for v6.16 2025-06-04 21:18:37 -07:00
io_uring io_uring-6.16-20250606 2025-06-06 13:09:03 -07:00
ipc - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
kernel The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
lib 13 hotfixes. 6 are cc:stable and the remainder address post-6.15 issues 2025-06-06 21:45:45 -07:00
LICENSES LICENSES: add CC0-1.0 license text 2025-05-21 14:54:17 +02:00
mm treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
net treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
rust Char/Misc/IIO pull request for 6.16-rc1 2025-06-06 11:50:47 -07:00
samples - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
scripts Kbuild updates for v6.16 2025-06-07 10:05:35 -07:00
security require gcc-8 and binutils-2.30 2025-05-31 08:16:52 -07:00
sound treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
tools turbostat v2025.06.08 2025-06-08 11:44:41 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge branch 'kvm-lockdep-common' into HEAD 2025-05-28 06:29:17 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore Python compiled bytecode 2025-04-24 10:12:46 -06:00
.mailmap fourteen smb3 client fixes, most smbdirect related 2025-06-08 10:20:21 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Update Christoph's Email address and make it consistent 2025-05-12 23:50:31 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS fourteen smb3 client fixes, most smbdirect related 2025-06-08 10:20:21 -07:00
Makefile Linux 6.16-rc1 2025-06-08 13:44:43 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.