Document the devicetree bindings for the real time clock found
on Microchip PIC32 class devices.
Signed-off-by: NJoshua Henderson <joshua.henderson@microchip.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The alarm for rx8025 only has a minute accuracy, so unsupport UIE mode.

pcf8563 and hym8563 also have a minute accuracy and unsupport it.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The alarm for rx8025 only has a minute accuracy, so round up to nearest
minute when setting alarm.  Without doing this, rtctest blocks one day
after setting alarm to 5 seconds later.

pcf8563 and hym8563 also have similar handling.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The ctrl1 register is accessed by alarm operations.  But it is updated
in threaded interrupt handler without acquiring rtc->ops_lock.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

When IRQ line for this chips is connected, devm_request_threaded_irq()
refuses to register irq handler with the following message.

genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Few functions were marked inline even though they were relatively large
and sometimes used in multiple places. De-inline them to let the
compiler decide whether optimization makes sense. This fixes inline_hunt
report:
drivers/rtc/rtc-s5m.c: Deinline s5m8767_rtc_set_alarm_reg, save 704 bytes
drivers/rtc/rtc-s5m.c: Deinline s5m8767_wait_for_udr_update, save 192 bytes
Reported-by: NDenys Vlasenko <vda.linux@googlemail.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The Makefile/Kconfig currently controlling compilation of this code is:

obj-$(CONFIG_RTC_CLASS)         += rtc-core.o
rtc-core-y                      := class.o interface.o

drivers/rtc/Kconfig:menuconfig RTC_CLASS
drivers/rtc/Kconfig:    bool "Real Time Clock"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the code there is no doubt it is builtin-only.

We don't replace module.h with init.h since the file does need
to know what a struct module is.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

When setting a new time/date the RTC's clock must be stopped first, in
order to write the time/date registers in an atomic manner.
So, this change stops the clock first and then writes the time/date
registers and the clock control register (to re-enable the clock) in one
turn.
Signed-off-by: NJuergen Borleis <jbe@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Check if the RTC signals an invalid time/date (due to a battery power loss
for example). In this case ignore the time/date until it is really set again.
Signed-off-by: NJuergen Borleis <jbe@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

By using i2c_smbus_read_i2c_block_data() the code is now much simpler.

While at it: when reading the RTC's seconds register, all time/date registers
are frozen until the RTC's year register is read. So it is important to read
all time/date registers in one turn to not lose a second event. Make it more
clear why the read must happen in this way.
Signed-off-by: NJuergen Borleis <jbe@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

pcf2123 has an offset register, which can be used to make minor
adjustments to the clock rate to compensate for temperature or
a crystal that is not exactly right.
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

clock offset may be set and read in decimal parts per billion
attribute is /sys/class/rtc/rtcN/offset
The attribute is only visible for rtcs that have set_offset implemented.
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

A number of rtc devices, such as the NXP pcf2123 include a facility
to adjust the clock in order to compensate for temperature or a
crystal, capacitor, etc, that results in the rtc clock not running
at exactly 32.768 kHz.

Data sheets I have seen refer to this as a clock offset, and measure it
in parts per million, however they often reference ppm to 2 digits of
precision, which makes integer ppm less than ideal.

We use parts per billion, which more than covers the precision needed
and works nicely within 32 bits
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Fix a scheduling while atomic issue caused by rv8803_set_time()
holding a spinlock during the call to i2c_smbus_read_byte_data().
Signed-off-by: NOleksij Rempel <fixed-term.Oleksij.Rempel@de.bosch.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Document Alphascale asm9260 RTC bindings
Signed-off-by: NOleksij Rempel <linux@rempel-privat.de>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Add support for RTC controller found on Alphascale asm9260
SoC.
Signed-off-by: NOleksij Rempel <linux@rempel-privat.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

DS3231 has programmable square-wave output signal.
This enables to use this feature as a clock provider of
common clock framework.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: NMichael Turquette <mturquette@baylibre.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

To make RTC block of MAX77686/MAX77802 as independent driver,
move the registration of i2c device, regmap for register access
and irq_chip for interrupt support inside the RTC driver.
Removed the same initialisation from MFD driver.

Having this change will allow to reuse this driver for different
PMIC/devices from Maxim Semiconductor if they kept same RTC IP on
different PMIC. Some of examples as PMIC MAX77620, MAX20024 where
same RTC IP used and hence driver for these chips will use this
driver only for RTC support.
Suggested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

There is different RTC I2C address for RTC block in MAX77686.
Driver is creating dummy i2c client for this address to access
the register of this IP block.

As there is no call to i2c_get_clientdata() for rtc_i2c client,
there is no need to store pointer and hence removing the call
to set client data for rtc i2c client.
Suggested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Get rid of referring parent device info for register access
all the places by making regmap as part of max77686 rtc
device info. This will also remove the need of storing parent
device info in max77686 rtc device info as this is no more required.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

rtc_regmap should be used to access all RTC registers instead
of parent regmap regardless of what chip or property have it.

This makes the register access uniform and extendible for other
chips.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Fix following check patch error in rtc-max77686 driver:
- Alignment should match open parenthesis.
- braces {} should be used on all arms of this statement.
- Prefer using the BIT macro
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

At the moment the "sun6i" RTC drivers depends on having two specific
SoC families selected.
The Allwinner A64 SoC has the same RTC, so extend the Kconfig option
to allow inclusion of the driver for all Allwinner SoCs.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The RX6110 comes in two different variants: SPI and I2C.
This driver only supports the SPI variant.

If the need ever arises to also support the I2C variant, this driver
could easily be refactored to support both cases.
Reviewed-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Add the binding documentation for the Epson RX6110 RTC.
Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

pcf2123 data sheet recommends a software reset when the chip
is first powered on. This change avoids resetting the chip
every time the driver is loaded, which has some negative effects.

There are several registers including a clock rate adjustment that really
should survive a reload of the driver (or reboot).

In addition, stopping and restarting the clock to verify the chip is
there is not a good thing once the time is set.

According to the data sheet, the seconds register has a 1 in
the high bit when the voltage has gotten low. We check for this
condition, as well as whether the time retrieved from the chip is
valid. We reset the rtc only if the time is not reliable and valid.
This is sufficient for checking for the presence of the chip,
as either all zeros or all 0xff will result in an invalid time/date
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Refactor chip reset items into its own function, isolating it from
the rest of the device probe.
Subsequent commits will avoid calling this code.
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Add new functions pcf2123_write(), and pcf2123_write_reg().
Use named defines for the values being written.

This improves modularity and readability, and reduces lines of code.
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Put read operations into a function.
This improves modularity and readability.
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Add defines for all 16 registers in the pcf2123.
Add defines for useful bits from several registers
I've tried to document all the registers, and
as best as possible, all the special bits they employ

Use BIT() wherever possible in the bit definitions
Signed-off-by: NJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

DS3231 has the temperature registers with a resolution of 0.25
degree celsius.  This enables to get the value through hwmon.

	# cat /sys/class/i2c-adapter/i2c-2/2-0068/hwmon/hwmon0/temp1_input
	21000
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

For RTC chips with no IRQ directly connected to the SoC, the RTC chip
can be forced as a wakeup source by stating that explicitly in
the device's .dts file using the "wakeup-source" boolean property.
This will guarantee the 'wakealarm' sysfs entry is available on the
device, if supported by the RTC.

With these changes to the driver rtc-ds1307 and the necessary entries
in the .dts file, I get an working ds1337 RTC on the Witty Pi extension
board by UUGear for the Raspberry Pi.

An example for the entry in the .dts file:

	rtc: ds1337@68 {
		compatible = "dallas,ds1337";
		reg = <0x68>;
		wakeup-source;

If the "wakeup-source" property is set, do not request an IRQ.
Set also UIE mode to unsupported, to get a working 'hwclock' binary.
Signed-off-by: NMichael Lange <linuxstuff@milaw.biz>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The mt6397 RTC driver can be built either when the MFD_MT6397 driver
is enabled (which selects IRQ_DOMAIN), or when compile testing.
The latter however fails without IRQ domains:

drivers/rtc/rtc-mt6397.c: In function 'mtk_rtc_probe':
drivers/rtc/rtc-mt6397.c:326:13: error: implicit declaration of function 'irq_create_mapping' [-Werror=implicit-function-declaration]
  rtc->irq = irq_create_mapping(mt6397_chip->irq_domain, res->start);

This adds an explicit dependency for the COMPILE_TEST case.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NEddie Huang <eddie.huang@mediatek.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The rv8803 has its own driver that should be used. Remove its id from
the rx8025 driver.

Fixes: b1f9d790Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

For better readability, use to_spi_device() and kobj_to_dev() instead
of container_of().
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

Cleanup of entire driver of its dmesg output:
1. Remove printing of the function name, because printing device name is
   sufficient. This also makes the dev_err()-like functions more compact
   and readable (not need of line break).
2. Lower from info to debug printing of each RTC interrupt (no need to
   make noise on each alarm).
3. Remove dev_info() at beginning of probe because a message is already
   always printed by either probe failure or from registering the RTC
   device as /dev/rtcX.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The max77686 RTC driver now supports the max77802 RTC as
well so there's no need to have a separate driver anymore.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NAndi Shyti <andi.shyti@samsung.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

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: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 6f1c1e71 ("mfd: max77686: Convert to use regmap_irq")
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The max77686 RTC only supports a range of 99 years so instead of using
year 1900 as the base, the year 2000 is used. This means that 1900 to
1999 are unsupported years.

The driver was printing a warning for those values but was returning a
error so for consistency, print an error message instead and don't say
that a year 2000 is assumed, since the year is not set.

Also, it is better to use dev_* log functions instead of pr_* to print
information about the device in the kernel log in a standardized way.

This also allows to remove the local pr_fmt() defined macro.
Suggested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NAndi Shyti <andi.shyti@samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The MAX77686 and MAX77802 RTC IP blocks are very similar with only
these differences:

0) The RTC registers layout and addresses are different.

1) The MAX77686 use 1 bit of the sec/min/hour/etc registers as the
   alarm enable while MAX77802 has a separate register for that.

2) The MAX77686 RTCYEAR register valid values range is 0..99 while
   for MAX77802 is 0..199.

3) The MAX77686 has a separate I2C address for the RTC registers
   while the MAX77802 uses the same I2C address as the PMIC regs.

5) The minimum delay before a RTC update (16 msecs vs 200 usecs).

There are separate drivers for MAX77686 and MAX77802 RTC IP blocks
but the differences are not that big so the driver can be extended
to support both instead of duplicating a lot of code in 2 drivers.
Suggested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NAndi Shyti <andi.shyti@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>