The pcf85263 RTC is compatible with the pcf85363 RTC.

The difference between the pcf85263 and pcf85363 RTC is that the latter has
64 bytes more RAM. This renders them incompatible from a DT point of view.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The RTC_VL_READ ioctl reports the low battery condition. Still,
pcf8523_rtc_read_time() happily returns invalid dates in this case.
Check the battery health on pcf8523_rtc_read_time() to avoid that.
Reported-by: Erik Čuk <erik.cuk@domel.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The example should follow the practice or using a generic node name
instead of the precise programming model, as recommended by the DTSpec.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: linux-pm@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k <linux-m68k@lists.linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Note, we drop the validation option. This is only used in
a deprecated ABI and is mostly wrong as many RTCs will still be valid
after 2100.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

There are users which print time and date represented by content of
struct rtc_time in human readable format.

Instead of open coding that each time introduce %ptR[dt][r] specifier.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The register range for the RTC extends beyond 0x54.
Use the size from the user manual's memory map instead.

Fixes: 9765d2d9 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The bindings have been updated to expose the RTC's internal oscillator,
for some SoCs that have it directly feeding the PRCM block. The changes
include the index 2 for the clock outputs, as well as the clock output
names.

This patch adds the internal oscillator to the list of clocks exposed
through of_clk_add_hw_provider(), and also have the driver optionally
fetch the name of the clock from the device tree if it's available.
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

There are different variants to the RTC hardware first seen on sun6i
(A31). The differences we care about in this driver are the clock rate
for the internal oscillator, prescalers, and the presence of an external
clock output.

This patch adds support for all the known pre-H6 base compatibles using
the variants data structure previously introduced.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Amongst the Allwinner SoCs that have seen some kind of coverage by the
linux-sunxi community, whether it be mainline Linux or U-boot support,
or just available datasheets, most newer chips use the RTC design first
seen in the A31 (sun6i).

Overall there have been some minor differences. This patch covers the
following:

  - average clock rate of the internal RC oscillator
    + presence of fixed and adjustable prescaler for this clock
  - availability of an external (to the SoC) clock output

One major difference regarding the H6 is the 24 MHz crystal is now
routed through the RTC, as a digitally compensated oscillator (DCXO).
This is not covered in this patch and will be supported later.

Other differences are either unrelated to RTC or clock functionality,
such as boot or crypto related registers, or the driver simply doesn't
use the feature in question. One example of the latter is the
calibration function for the RC oscillator. We consider this clock to
be very bad and avoid using it.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The RTC's main clock, used internally and exported to the rest of the
SoC, is called "LOSC" (low speed oscillator) through the hardware
documentation.

This patch adds a default name for this clock, in case the device tree
does not provide one. This shouldn't happen, but lets play it safe.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Experiments showed that on at least the H3/H5/A64 the RTC's internal
oscillator also feeds the CPUS mux in the PRCM.

Export this clock through the device tree, instead of having to use
a dummy fixed-clock device node, for the PRCM to consume. This will
properly describe the relationship between the clocks.
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The A31 does not have an external clock output directly from the RTC.
Instead, it has four muxable clock outputs: three (A, B, C) are
controlled from the CCU, and the last (D) is controlled from the PRCM.

Deprecate the usage of the external clock output for the A31 compatible.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

While doing Bluetooth enablement for various boards based on various
Allwinner SoCs, minor differences in the RTC modules were found. These
include a lack of an external clock output (A31), different internal
oscillator frequencies (H3/H5/A64/V3/V3s), different regulator voltage
settings (H5/H6), and the presence of miscellaneous registers unrelated
to the RTC (A64/R40/H5/H6). The datasheet also describes different number
of registers for non-volatile storage, though based on actual experiments
the actual number is the same across the board.

This patch adds a list of all pre-H6 variants, grouped by the internal
oscillator's clock rate, regulator settings, and the presence of the
external clock output. Combinations are introduced for the variants that
have miscellaneous registers.

The RTC block in the H6 also handles the 24 MHz DCXO. This will require
more device tree binding changes and will be done later.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The clock output section for this binding describes the two outputs in
the descriptions for both the #clock-cells and clock-output-names
properties.

Instead of overlapping information that is hard to read, rewrite the
clock outputs as a list of indices and descriptions. The properies
can reference this list instead. This will also make it easier to
add notes or conditions to the clocks, and also for adding new outputs.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The abracon,tc-resistor property value is in kOhm.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The Linux i2c layer has functions to execute common SMBUS/I2C
transactions.  The register access code here is identical to the I2C
read/write block data routines.

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>

In case of error, we return 0.
This is spurious and not consistent with the other functions of the driver.
Propagate the error code instead.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Using devm_nvmem_register allows to avoid tracking the nvmem pointer in the
rtc_device structure.
This ultimately allows to register multiple nvmem devices from an RTC
driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use the resource managed variant of nvmem_register().
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

In case of error, we return 0.
This is spurious and not consistent with the other functions of the driver.
Commit e115a2bf has modified more than what is said in the commit
message. Reverse part of it znd return an error when needed, as it was
previously.

Fixes: e115a2bf ("rtc: max77686: stop validating rtc_time in .read_time")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

(RTC,ALM)YEAR registers of Exynos built-in RTC device contains 3 BCD
characters. s3c-rtc driver uses only 2 lower of them and supports years
from 2000..2099 range. The third BCD value is typically set to 0, but it
looks that handling of it is broken in the hardware. It sometimes
defaults to a random (even non-BCD) value. This is not an issue
for handling RTCYEAR register, because bcd2bin() properly handles only
8bit values (2 BCD characters, the third one is skipped). The problem
is however with ALMYEAR register and proper RTC alarm operation. When
YEAREN bit is set for the configured alarm, RTC hardware triggers alarm
only when ALMYEAR and RTCYEAR matches. This usually doesn't happen
because of the random noise on the third BCD character.

Fix this by simply skipping setting ALMYEAR register in alarm
configuration. This workaround fixes broken alarm operation on Exynos
built-in rtc device. My tests revealed that the issue happens on the
following Exynos series: 3250, 4210, 4412, 5250 and 5410.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Complement commit 85d77047 ("drivers/rtc/rtc-m41t80.c: propagate
error value from smbus functions") and correct the remaining places that
fail to propagate the error code from SMBus calls.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
References: 85d77047 ("drivers/rtc/rtc-m41t80.c: propagate error value from smbus functions")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>