linux.git/drivers/rtc, branch v6.1.154

rtc: ds1307: remove clear of oscillator stop flag (OSF) in probe

2025-08-28T14:26:03+00:00

[ Upstream commit 48458654659c9c2e149c211d86637f1592470da5 ]

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.

Some chip types in the ds1307 driver already have OSF handling to
determine whether .read_time provides valid RTC data or returns -EINVAL.

This change removes the clear of the OSF in .probe as the OSF needs to
be preserved to expand the OSF handling to the ds1341 chip type (note
that DS1341 and DS1342 share a datasheet).

Signed-off-by: Meagan Lloyd 
Reviewed-by: Tyler Hicks 
Acked-by: Rodolfo Giometti 
Link: https://lore.kernel.org/r/1749665656-30108-2-git-send-email-meaganlloyd@linux.microsoft.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: ds1307: handle oscillator stop flag (OSF) for ds1341

2025-08-28T14:26:01+00:00

[ Upstream commit 523923cfd5d622b8f4ba893fdaf29fa6adeb8c3e ]

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 
Reviewed-by: Tyler Hicks 
Acked-by: Rodolfo Giometti 
Link: https://lore.kernel.org/r/1749665656-30108-3-git-send-email-meaganlloyd@linux.microsoft.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: rv3028: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit b574acb3cf7591d2513a9f29f8c2021ad55fb881 ]

When rv3028_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: f583c341a515f ("rtc: rv3028: add clkout support")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-6-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: pcf8563: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit 906726a5efeefe0ef0103ccff5312a09080c04ae ]

When pcf8563_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: a39a6405d5f94 ("rtc: pcf8563: add CLKOUT to common clock framework")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-5-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: pcf85063: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit 186ae1869880e58bb3f142d222abdb35ecb4df0f ]

When pcf85063_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: 8c229ab6048b7 ("rtc: pcf85063: Add pcf85063 clkout control to common clock framework")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-4-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: nct3018y: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit 437c59e4b222cd697b4cf95995d933e7d583c5f1 ]

When nct3018y_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: 5adbaed16cc63 ("rtc: Add NCT3018Y real time clock driver")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-3-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: hym8563: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit d0a518eb0a692a2ab8357e844970660c5ea37720 ]

When hym8563_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: dcaf038493525 ("rtc: add hym8563 rtc-driver")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-2-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: ds1307: fix incorrect maximum clock rate handling

2025-08-15T10:05:06+00:00

[ Upstream commit cf6eb547a24af7ad7bbd2abe9c5327f956bbeae8 ]

When ds3231_clk_sqw_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: 6c6ff145b3346 ("rtc: ds1307: add clock provider support for DS3231")
Signed-off-by: Brian Masney 
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-1-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: cmos: use spin_lock_irqsave in cmos_interrupt

2025-07-10T13:59:43+00:00

commit 00a39d8652ff9088de07a6fe6e9e1893452fe0dd upstream.

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 6950d046eb6e ("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 13be2efc390a ("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: 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
Signed-off-by: Mateusz Jończyk 
Reviewed-by: Sebastian Andrzej Siewior 
Tested-by: Chris Bainbridge 
Reported-by: Chris Bainbridge 
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 
Signed-off-by: Greg Kroah-Hartman

rtc: sh: assign correct interrupts with DT

2025-06-27T10:07:15+00:00

[ Upstream commit 8f2efdbc303fe7baa83843d3290dd6ea5ba3276c ]

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: dab5aec64bf5 ("rtc: sh: add support for rza series")
Signed-off-by: Wolfram Sang 
Link: https://lore.kernel.org/r/20250227134256.9167-11-wsa+renesas@sang-engineering.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin