rtc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230724205456.767430-1-robh@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230505121136.1185653-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: Add nvmem support

This adds support for the 256-byte internal RAM. There are two windows
which can be used to access this RAM: 64 bytes at 0x40 (the "standard"
address space) and 128 bytes at 0x80 (the "alternate" address space). We
use the standard address space because it is also accessible over SPI
(if such a port is ever done). We are limited to 32-byte reads for SMBus
compatibility, so there's no advantage to using the alternate address
space.

There are some reserved bits in the EXTRAM register, and the datasheet
doesn't say what to do with them. I've opted to skip a read/modify/write
and just write the whole thing. If this driver is ever converted to
regmap, this would be a good place to use regmap_update_bits.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20221222214532.1873718-1-sean.anderson@seco.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: Include <linux/kstrtox.h> when appropriate

The kstrto<something>() functions have been moved from kernel.h to
kstrtox.h.

So, include the latter directly in the appropriate files.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/786421fd0435a32206288904a1f879436a717529.1667721637.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: Convert to .probe_new()

.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in .probe(). The device_id array has to move up for that
to work.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221021130706.178687-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: Add utility function for writing configuration key

Writing one of key two values into the configuration key register
is a common operation, so a utility function has been added to
provide consistent behavior and eliminate code duplication.

Signed-off-by: Kevin P. Fleming <kevin+linux@km6g.us>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: linux-rtc@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200615105113.57770-2-kevin+linux@km6g.us

rtc: rework rtc_register_device() resource management

rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl

rtc: abx80x: Provide debug feedback for invalid dt properties

When the user provides an invalid value for tc-diode or
tc-resistor generate a debug message instead of silently
ignoring it.

Signed-off-by: Kevin P. Fleming <kevin+linux@km6g.us>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200530122956.360689-1-kevin+linux@km6g.us

rtc: abx80x: Add Device Tree matching table

Enable automatic loading of the module when a Device Tree overlay
specifies a device supported by this driver.

Signed-off-by: Kevin P. Fleming <kevin+linux@km6g.us>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200528114617.166587-1-kevin+linux@km6g.us

rtc: abx80x: return meaningful value for RTC_VL_READ

ABX8XX_STATUS_BLF indicates the battery is low and needs to be replaced
soon.

Link: https://lore.kernel.org/r/20191214220259.621996-4-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: remove useless .remove

.remove is empty, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: use rtc_add_group

Use rtc_add_group to add the sysfs group in a race free manner.
This has the side effect of moving the files to their proper location.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: convert to SPDX identifier

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

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: update my email address

Use my current email address.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: Configure reserved bits in RV1805

The RV1805 uses smaller package than the AB1805, discern those two
chips based on the compatible value and configure reserved bits in
the RV1805 to prevent current leakage and accidental test mode entry.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: linux-rtc@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: Implement RTC_VL_READ,CLR ioctls

Implement standard ioctls for polling the battery status and clearing
the battery low indication from userspace.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: add basic watchdog support

The abx804 and abx805 chips have support for a simple watchdog
function that can trigger an external reset.

Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: use a 'priv' struct for client data

This will allow additional data to be tracked, for future
improvements.

Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: remove useless message

It is not necessary to print a message when the time is invalid as
userspace will already get an error (and an optional dev_dbg message).

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: abx80x: solve race condition

There is a race condition that can happen if abx80x_probe() fails after the
rtc registration succeeded. Solve that by moving the registration at the
end of the probe function.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: switch to rtc_register_device

This allows for future improvement of the driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: use devm_add_action_or_reset()

If devm_add_action() fails we are explicitly calling the cleanup to free
the resources allocated. Lets use the helper devm_add_action_or_reset()
and return directly in case of error, as we know that the cleanup function
has been already called by the helper if there was any error.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: handle the oscillator failure bit

Handle the Oscillator Failure ('OF') bit from Oscillator Status register
(0x1D). This bit is cleared on set_time function and is read each time the
date/time is read, but only in case of XT Oscillator selection.
In RC mode, this bit is always set.

Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: handle autocalibration

The autocalibration is separated in two bits to set in Oscillator
Control register (0x1c) :
- OSEL bit to select the oscillator type (XT or RC).
- ACAL bit to select the autocalibration type.

These functionnalities are exported in sysfs entries : "oscillator"
and "autocalibration". Respectively, the values are "xtal" for XT
oscillator and "rc" for RC oscillator and 0 to disable the
autocalibration cycle, 512 for a 512 seconds autocalibration cycle
and 1024 for a cycle of 1024 seconds.

Examples :
Set to XT Oscillator
echo xtal > /sys/class/rtc/rtc0/device/oscillator
Activate an autocalibration every 512 seconds
echo 512 > /sys/class/rtc/rtc0/device/autocalibration

Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: add alarm support

Add alarm support to the abx80x driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: Add Microcrystal rv1805 support

Microcrystal RV-1805 is compatible with Abracon 1805.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: abx80x: fix RTC write bit

Fix RTC write bit as per application manual

Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Mitja Spes <mitja@lxnav.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: add rtc-abx80x, a driver for the Abracon AB x80x i2c rtc

This is a basic driver for the ultra-low-power Abracon AB x80x series of RTC
chips. It supports in particular, the supersets AB0805 and AB1805.
It allows reading and writing the time, and enables the supercapacitor/
battery charger.

[arnd@arndb.de: abx805 depends on i2c]
[alexandre.belloni@free-electrons.com: renam buffer from date to buf in abx80x_rtc_read_time()]
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>