linux-stable.git/drivers/rtc, branch v4.1.41

rtc: tegra: Implement clock handling

2017-06-13T13:29:17+00:00

[ Upstream commit 5fa4086987506b2ab8c92f8f99f2295db9918856 ]

Accessing the registers of the RTC block on Tegra requires the module
clock to be enabled. This only works because the RTC module clock will
be enabled by default during early boot. However, because the clock is
unused, the CCF will disable it at late_init time. This causes the RTC
to become unusable afterwards. This can easily be reproduced by trying
to use the RTC:

	$ hwclock --rtc /dev/rtc1

This will hang the system. I ran into this by following up on a report
by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It
turns out that the rtc-tegra driver's ->shutdown() implementation will
hang the CPU, because of the disabled clock, before the system can be
rebooted.

What confused me for a while is that the same driver is used on prior
Tegra generations where the hang can not be observed. However, as Peter
De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC
clock is enabled by the tegra20_timer.c clocksource driver, which uses
the RTC to provide a persistent clock. This code is never enabled on
64-bit Tegra because the persistent clock infrastructure does not exist
on 64-bit ARM.

The proper fix for this is to add proper clock handling to the RTC
driver in order to ensure that the clock is enabled when the driver
requires it. All device trees contain the clock already, therefore
no additional changes are required.

Reported-by: Martin Michlmayr 
Acked-By Peter De Schrijver 
Signed-off-by: Thierry Reding 
Signed-off-by: Alexandre Belloni 

Signed-off-by: Sasha Levin

rtc: sun6i: Switch to the external oscillator

2017-05-17T19:06:58+00:00

[ Upstream commit fb61bb82cb46a932ef2fc62e1c731c8e7e6640d5 ]

The RTC is clocked from either an internal, imprecise, oscillator or an
external one, which is usually much more accurate.

The difference perceived between the time elapsed and the time reported by
the RTC is in a 10% scale, which prevents the RTC from being useful at all.

Fortunately, the external oscillator is reported to be mandatory in the
Allwinner datasheet, so we can just switch to it.

Cc: stable@vger.kernel.org
Fixes: 9765d2d94309 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Maxime Ripard 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: sun6i: Add some locking

2017-05-17T19:06:58+00:00

[ Upstream commit a9422a19ce270a22fc520f2278fb7e80c58be508 ]

Some registers have a read-modify-write access pattern that are not atomic.

Add some locking to prevent from concurrent accesses.

Cc: stable@vger.kernel.org
Acked-by: Chen-Yu Tsai 
Signed-off-by: Maxime Ripard 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()

2016-08-20T03:07:58+00:00

[ Upstream commit 70c96dfac0e231424e17743bd52f6cd2ff1f2439 ]

As per code flow s3c_rtc_setfreq() will get called with rtc clock disabled
and in set_freq we perform h/w registers read/write, which results in a
kernel crash on exynos7 platform while probing rtc driver.
Below is code flow:
s3c_rtc_probe()
    clk_prepare_enable(info->rtc_clk) // rtc clock enabled
    s3c_rtc_gettime() // will enable clk if not done, and disable it upon exit
    s3c_rtc_setfreq() //then this will be called with clk disabled

This patch take cares of such issue by adding s3c_rtc_{enable/disable}_clk in
s3c_rtc_setfreq().

Fixes: 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock control")

Cc: 
Signed-off-by: Alim Akhtar 
Reviewed-by: Krzysztof Kozlowski 
Reviewed-by: Pankaj Dubey 
Tested-by: Pankaj Dubey 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: max77686: Properly handle regmap_irq_get_virq() error code

2016-07-11T03:07:14+00:00

[ Upstream commit fb166ba1d7f0a662f7332f4ff660a0d6f4d76915 ]

The regmap_irq_get_virq() can return 0 or -EINVAL in error conditions
but driver checked only for value of 0.

This could lead to a cast of -EINVAL to an unsigned int used as a
interrupt number for devm_request_threaded_irq(). Although this is not
yet fatal (devm_request_threaded_irq() will just fail with -EINVAL) but
might be a misleading when diagnosing errors.

Signed-off-by: Krzysztof Kozlowski 
Fixes: 6f1c1e71d933 ("mfd: max77686: Convert to use regmap_irq")
Reviewed-by: Javier Martinez Canillas 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: ds1685: passing bogus values to irq_restore

2016-07-11T03:07:13+00:00

[ Upstream commit 8c09b9fdecab1f4a289f07b46e2ad174b6641928 ]

We call spin_lock_irqrestore with "flags" set to zero instead of to the
value from spin_lock_irqsave().

Fixes: aaaf5fbf56f1 ('rtc: add driver for DS1685 family of real time clocks')
Signed-off-by: Dan Carpenter 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: vr41xx: Wire up alarm_irq_enable

2016-07-11T03:07:13+00:00

[ Upstream commit a25f4a95ec3cded34c1250364eba704c5e4fdac4 ]

drivers/rtc/rtc-vr41xx.c:229: warning: ‘vr41xx_rtc_alarm_irq_enable’ defined but not used

Apparently the conversion to alarm_irq_enable forgot to wire up the
callback.

Fixes: 16380c153a69c378 ("RTC: Convert rtc drivers to use the alarm_irq_enable method")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: hym8563: fix invalid year calculation

2016-07-11T03:07:13+00:00

[ Upstream commit d5861262210067fc01b2fb4f7af2fd85a3453f15 ]

Year field must be in BCD format, according to
hym8563 datasheet.

Due to the bug year 2016 became 2010.

Fixes: dcaf03849352 ("rtc: add hym8563 rtc-driver")
Signed-off-by: Alexander Kochetkov 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin

rtc: abx80x: fix RTC write bit

2015-09-29T17:26:11+00:00

commit 5f1b2f77646fc0ef2f36fc554f5722a1381d0892 upstream.

Fix RTC write bit as per application manual

Signed-off-by: Mitja Spes 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman

rtc: s5m: fix to update ctrl register

2015-09-29T17:26:11+00:00

commit ff02c0444b83201ff76cc49deccac8cf2bffc7bc upstream.

According to datasheet, the S2MPS13X and S2MPS14X should update write
buffer via setting WUDR bit to high after ctrl register is written.

If not, ALARM interrupt of rtc-s5m doesn't happen first time when i use
tools/testing/selftests/timers/rtctest.c test program and hour format is
used to 12 hour mode in Odroid-XU3 board.

One more issue is the RTC doesn't keep time on Odroid-XU3 board when i
turn on board after power off even if RTC battery is connected. It can
be solved as setting WUDR & RUDR bits to high at the same time after
RTC_CTRL register is written. It's same with condition of only writing
ALARM registers, so this is for only S2MPS14 and we should set WUDR &
A_UDR bits to high on S2MPS13.

I can't find any reasonable description about this like fix from
datasheet, but can find similar codes from rtc driver source of
hardkernel kernel and vendor kernel.

Signed-off-by: Joonyoung Shim 
Reviewed-by: Krzysztof Kozlowski 
Tested-by: Krzysztof Kozlowski 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman