Let the core handle the RTC range instead of open coding it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This allows further improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use my current email address.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use SPDX-License-Identifier instead of a verbose license text.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Let the core handle the RTC range instead of open coding it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use SPDX-License-Identifier instead of a verbose license text.

The original text refers to the COPYING file in the main directory which is
GPL v2 only so also update MODULE_LICENSE() to "GPL v2" instead of "GPL".
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Switch from .set_mmss to .set_time as the former is deprecated.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Call the 64bit versions of rtc_time_to_tm now that the range is enforced by
the core.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The TX4939 RTC is a 48bit counter that counts two on every clock edge of
32.768 KHz oscillator clock so it counts 32bit seconds.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The tested condition will never happen as the core always passes a fully
set struct tm (using rtc_ktime_to_tm) to the .set_alarm callback.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Let the core handle the RTC range instead of open coding it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
struct before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The imx-sc driver properly sets range_max, use rtc_time64_to_tm() instead
of the deprecated rtc_time_to_tm()
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add support for Epson rx8571 real-time clock. rx8571 rtc is compatible
with rx8581,except that rx8571 has additional 16 bytes of RAM.

16 bytes of nvmem is supported and exposed in sysfs (# is the instance
number,starting with 0): /sys/bus/nvmem/devices/rx8571-#/nvmem
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The Epson rx8571 is compatible with the Epson rx8581 RTC.

The difference between the rx8571 and rx8581 RTC is that the former has
16 bytes more RAM. This renders them incompatible from a DT point of view.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Some of defines are not in use since
7b576848. Remove it to make the code
easier to read and understand.
Signed-off-by: Alexey Roslyakov <alexey.roslyakov@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Since commit 416f0e80 ("RTC: sa1100: Update the sa1100 RTC driver."),
the last user of .read_callback is gone. It has been 8 years and now new
user appeared. Simply remove it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This patch adds support for AB-RTCMC-32.768kHz-EOZ9 RTC/Calendar
module with I2C interface.
Signed-off-by: Artem Panfilov <panfilov.artyom@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add ABEOZ9 to the list of trivial RTCs
Signed-off-by: Artem Panfilov <panfilov.artyom@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Make RTC_DRV_HID_SENSOR_TIME depend on IIO and HID_SENSOR_HUB to remove
possible circular dependencies as this is the only symbol selecting those.
Suggested-by: Florian Lohoff <f@zz.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add a driver for the MicroCrystal RV-3028. It is a SMT Real-Time Clock
Module that incorporates an integrated CMOS circuit together with an XTAL.
It has an i2c interface.

The driver handles date/time, alarms, trickle charging, timestamping,
frequency offset correction, EEPROM and NVRAM.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Since this documents multiple chips controlled by the isl1208 driver,
name it isil,isl1208.txt, as the convention is to use the base driver
name in the bindings document for drivers with multiple devices.

Include all chips supported by this driver in the docs.  Make it
clear which properties apply to which chips.

Expand documentation for existing isil,evienb property to explain
operation in more detail.  Existing docs just describe it in terms of
setting a bit in a register.

CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Alexandre Belloni <alexandre.belloni@bootlin.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Mark Rutland <mark.rutland@arm.com>
CC: devicetree@vger.kernel.org
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add support for the RTC's NVRAM using the standard nvmem support that is
part of the Linux RTC framework.

This driver already has a sysfs attribute that provides access to the
RTC's NVRAM as a single 16-bit value.  Some chips have more than two
bytes of NVRAM, so this will not work for them.  It's also non-standard.

This sysfs attribute is left in for backward compatibility, but will only
be able to read the first two bytes of NVRAM.  The nvmem interface will
allow access to all NVRAM, e.g. eight bytes on the isl1218.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add more support in the driver for dealing with differences in is1208
compatible chips.  Put the 1208, 1209, 1218, and 1219 in the list and
encode information about nvram size, tamper, and timestamp features.

This adds support for the isl1209, which has a tamper detect but no
timestamp feature.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This driver has no state of its own, depending entirely on what is in
the generic rtc device.

Intoduce a state struct.  For now it only contains a pointer to the rtc
device struct, but future patches will add more data.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc_nvmem_unregister() is called on rtc_device release so it is not
necessary to call it from the driver.
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Add support for the RTC block on the 32-bit Amlogic Meson6, Meson8,
Meson8b and Meson8m2 SoCs.

The RTC is split in to two parts, which are both managed by this driver:
- the AHB front end
- and a simple serial connection to the actual registers

The RTC_COUNTER register which holds the time is 32-bits wide.

There are four 32-bit wide (in total: 16 bytes) "regmem" registers which
are exposed using nvmem. On Amlogic's 3.10 kernel this is used to store
data which needs to survive a suspend / resume cycle.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[resurrected Ben's patches after 2 years]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The 32-bit Amlogic Meson SoCs (Meson6, Meson8, Meson8b and Meson8m2)
have a built-in RTC block.
It has the following inputs:
- an 32.768kHz crystal oscillator
- an interrupt line
- a reset line
- 0.9V voltage input
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[resurrected patches from Ben after 2 years]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

When the oscillator of the rtc gets interrupted,
e.g. due to an empty battery, reading from the rtc will now return an error
and the oscillator bit will be cleared, once the rtc is successfully reset.
Signed-off-by: Oliver Rohe <oliver.rohe@wago.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Fix the following build issue:

drivers/rtc/rtc-imx-sc.o: In function `imx_sc_rtc_set_time':
>> rtc-imx-sc.c:(.text+0x212): undefined reference to `__arm_smccc_smc'

Fixes: 13a929f3 ("rtc: imx-sc: add rtc set time support")
Reviewed-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Shifting a u8 by 24 will cause the value to be promoted to an integer. If
the top bit of the u8 is set then the following conversion to an unsigned
long will sign extend the value causing the upper 32 bits to be set in
the result.

Fix this by casting the u8 value to an unsigned long before the shift.

Detected by CoverityScan, CID#1309693 ("Unintended sign extension")

Fixes: 9a9a54ad ("drivers/rtc: add support for Qualcomm PMIC8xxx RTC")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Shifting a u8 by 24 will cause the value to be promoted to an integer. If
the top bit of the u8 is set then the following conversion to an unsigned
long will sign extend the value causing the upper 32 bits to be set in
the result.

Fix this by casting the u8 value to an unsigned long before the shift.

Detected by CoverityScan, CID#714646-714649 ("Unintended sign extension")

Fixes: 2985c29c ("rtc: Add rtc support to 88PM80X PMIC")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Shifting a u8 by 24 will cause the value to be promoted to an integer. If
the top bit of the u8 is set then the following conversion to an unsigned
long will sign extend the value causing the upper 32 bits to be set in
the result.

Fix this by casting the u8 value to an unsigned long before the shift.

Detected by CoverityScan, CID#144925-144928 ("Unintended sign extension")

Fixes: 008b3040 ("mfd: Add rtc support to 88pm860x")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

When the EXTENSION.WADA bit is set, register 0x19 contains a bitmap of
week days, not a day of month. As Linux only handles a single alarm
without repetition using day of month is more flexible, so clear this
bit. (Otherwise a value depending on time.tm_wday would have to be
written to register 0x19.)

Also optimize setting the AIE bit to use a single register write instead
of a bulk write of three registers.

Fixes: ee0981be ("rtc: ds1307: Add support for Epson RX8130CE")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

When voltage dropped since the RTC was last set the reported time is not
reliable. In this case return an error indicator instead of a bogus
time.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

While rx8130 has a register offset of 0x10 in its chip_desc, this isn't
used when regmap accesses are done. So add 0x10 to access the right
locations.

Fixes: ee0981be ("rtc: ds1307: Add support for Epson RX8130CE")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

There used to be 16 declarations for static functions. By just adding a
declaration for the chips array and reordering the functions the 16
function declarations can be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This allows to use the register offsets in all functions
which is needed in one of the next patches.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This patch adds i.MX system controller RTC set time support, the
RTC set time is implemented via SIP(silicon provider) runtime
service call and ARM-Trusted-Firmware will communicate with system
controller via MU(message unit) IPC to set RTC time.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The Ricoh chips have slightly different register layouts
and the r2221 chip uses bit 5 as the oscillator halt sensor bit.
Signed-off-by: Olive Rohe <oliver.rohe@wago.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>