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: 9765d2d943 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This patches fixes comparison between signed and unsigned values as it
could produce an incorrect result when the signed value is converted to
unsigned:
drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_valid_alrm':
drivers/rtc/rtc-stm32.c:404:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if ((((tm->tm_year > cur_year) &&
...
It also fixes comparison always true or false due to the fact that unsigned
value is compared against zero with >= or <:
drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_init':
drivers/rtc/rtc-stm32.c:514:35: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
for (pred_a = pred_a_max; pred_a >= 0; pred_a-- ) {
drivers/rtc/rtc-stm32.c:530:44: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
(rate - ((pred_a + 1) * (pred_s + 1)) < 0) ?
Fixes: 4e64350f42 ("rtc: add STM32 RTC driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Using the ~ operator on a BIT() constant results in a large 'unsigned long'
constant that won't fit into an 'unsigned int' function argument on 64-bit
architectures, resulting in a harmless build warning in x86 allmodconfig:
drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_probe':
drivers/rtc/rtc-stm32.c:651:51: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);
As PWR_CR_DBP mask prevents other bits to be cleared, replace all
~PWR_CR_DBP by 0.
Fixes: 4e64350f42 ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
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 <tbm@cyrius.com>
Acked-By Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The ordering of includes is currently completely arbitrary, making it
impossible to decide where to put new includes. Remove the dilemma by
sort the include list alphabetically.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The new driver has a stray #ifdef in it that causes a build error:
drivers/rtc/rtc-stm32.c:718:21: error: 'stm32_rtc_of_match' undeclared here (not in a function); did you mean 'stm32_rtc_pm_ops'?
As the #ifdef serves no purpose here, let's just remove it.
Fixes: 4e64350f42 ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The remove function can be called at runtime for a manual 'unbind'
operation and must not be left out from a built-in driver, as kbuild
complains:
`stm32_rtc_remove' referenced in section `.data.stm32_rtc_driver' of drivers/rtc/rtc-stm32.o: defined in discarded section `.exit.text' of drivers/rtc/rtc-stm32.o
This removes the extraneous annotation.
Fixes: 4e64350f42 ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Armada38x wants to modify its rtc_class_ops to remove the interrupt
handling when there is no usable interrupt, but this means we leave
function pointers in writable memory.
Since rtc_class_ops is small, arrange to have two instances, one for
when we have interrupts, and one for when we have none, both marked
const. This allows the compiler to place them in read-only memory,
which is better than placing them in __ro_after_init.
Thanks to Bhumika Goyal <bhumirks@gmail.com> for pointing out that
the structure was writable and submitting a patch to add
__ro_after_init.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Declare rtc_class_ops structures as const as they are only passed
as an argument to the function devm_rtc_device_register. This argument
is of type const struct rtc_class_ops *, so rtc_class_ops structures
having this property can be declared const.
Done using Coccinelle:
@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct rtc_class_ops i@p = {...};
@ok1@
identifier r1.i;
position p;
@@
devm_rtc_device_register(...,&i@p,...)
@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p
@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct rtc_class_ops i;
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The DryIce chipset has a dedicated security violation interrupt that is
triggered for security violations (if configured to do so). According
to the publicly available imx258 reference manual, irq 56 is used for
this interrupt.
If an irq number is provided for the security violation interrupt,
install the same handler that we're already using for the "normal"
interrupt.
imxdi->irq is used only in the probe function, make it a local variable.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This patch adds alarm support. This allows to configure the chip
to generate an interrupt when the alarm matches current time value.
Alarm can be programmed up to one year in the future
and is accurate to the second.
Signed-off-by: Emil Bartczak <emilbart@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
According to RES-3124064:
The device supports CPU write and read access to the RTC time register.
However, due to this restriction, read and write from/to internal RTC
register may fail.
Workaround:
General setup:
1. Configure the RTC Mbus Bridge Timing Control register (offset 0x184A0)
to value 0xFD4D4FFF
Write RTC WRCLK Period to its maximum value (0x3FF)
Write RTC WRCLK setup to 0x29
Write RTC WRCLK High Time to 0x53 (default value)
Write RTC Read Output Delay to its maximum value (0x1F)
Mbus - Read All Byte Enable to 0x1 (default value)
2. Configure the RTC Test Configuration Register (offset 0xA381C) bit3
to '1' (Reserved, Marvell internal)
For any RTC register read operation:
1. Read the requested register 100 times.
2. Find the result that appears most frequently and use this result
as the correct value.
For any RTC register write operation:
1. Issue two dummy writes of 0x0 to the RTC Status register (offset
0xA3800).
2. Write the time to the RTC Time register (offset 0xA380C).
This patch is based on the work of Shaker Daibes
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Texas Instrument's TPS65910 has support for compensating RTC crystal
inaccuracies. When enabled every hour RTC counter value will be compensated
with two's complement value.
Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.
Get rid of the union and just keep ktime_t as simple typedef of type s64.
The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Pull RTC updates from Alexandre Belloni:
"Subsystem:
- non-modular drivers are now explicitly non-modular
New driver:
- Epson Toyocom rtc-7301sf/dg
Drivers:
- cmos: reject unsupported alarm values wrt the RTC capabilities
- ds1307: ACPI support
- jz4740: DT support, jz4780 handling, can now be used as a system
power controller
- mcp795: many fixes, in particular proper month handling
- twl: driver is now DT only"
* tag 'rtc-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (31 commits)
rtc: mcp795: Fix whitespace and indentation.
rtc: mcp795: Prefer using the BIT() macro.
rtc: mcp795: fix month write resetting date to 1.
rtc: mcp795: fix time range difference between linux and RTC chip.
rtc: mcp795: fix bitmask value for leap year (LP).
rtc: mcp795: use bcd2bin/bin2bcd.
rtc: add support for EPSON TOYOCOM RTC-7301SF/DG
rtc: ds1307: Add ACPI support
rtc: imxdi: (trivial) fix a typo
rtc: ds1374: Merge conditional + WARN_ON()
rtc: twl: make driver DT only
rtc: twl: kill static variables
rtc: fix typos in Kconfig
rtc: jz4740: make the driver builtin only
rtc: jz4740: remove unused EXPORT_SYMBOL
Documentation: bindings: fix twl-rtc documentation
rtc: Enable compile testing for Maxim and Samsung drivers
MIPS: jz4740: Remove obsolete code
MIPS: qi_lb60: Probe RTC driver from DT and use it as power controller
MIPS: jz4740: DTS: Probe the jz4740-rtc driver from devicetree
...
Fix whitespace and indentation errors and the following
checkpatch warnings:
- line 15: Block comments use a trailing */ on a separate line
- line 256: Line over 80 characters
No code change.
Signed-off-by: Emil Bartczak <emilbart@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Maxime Ripard
Linus Walleij
Amelie Delaunay
Thierry Reding
Arnd Bergmann
Russell King
Bhumika Goyal
Martin Kaiser
Emil Bartczak
Gregory CLEMENT
Vesa Jääskeläinen
Fabien Lahoudere
Thomas Gleixner
Linus Torvalds