rtc: nct3018y: fix possible NULL dereference

alarm_enable and alarm_flag are allowed to be NULL but will be dereferenced
later by the dev_dbg call.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202305180042.DEzW1pSd-lkp@intel.com/
Link: https://lore.kernel.org/r/20240229222127.1878176-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: nuvoton: Compatible with NCT3015Y-R and NCT3018Y-R

The NCT3015Y-R and NCT3018Y-R use the same datasheet
but have different topologies as follows.
- Topology (Only 1st i2c can set TWO bit and HF bit)
In NCT3015Y-R,
rtc 1st i2c is connected to a host CPU
rtc 2nd i2c is connected to a BMC
In NCT3018Y-R,
rtc 1st i2c is connected to a BMC
rtc 2nd i2c is connected to a host CPU
In order to be compatible with NCT3015Y-R and NCT3018Y-R,
- In probe,
If part number is NCT3018Y-R, only set HF bit to 24-Hour format.
Else, do nothing
- In set_time,
If part number is NCT3018Y-R && TWO bit is 0,
change TWO bit to 1, and restore TWO bit after updating time.

Signed-off-by: Mia Lin <mimi05633@gmail.com>
Link: https://lore.kernel.org/r/20231113103807.1036978-2-mimi05633@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: remove redundant of_match_ptr()

Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Link: https://lore.kernel.org/r/20230808115213.154377-2-wangzhu9@huawei.com
Link: https://lore.kernel.org/r/20230808115213.154377-3-wangzhu9@huawei.com
Link: https://lore.kernel.org/r/20230808115213.154377-4-wangzhu9@huawei.com
Link: https://lore.kernel.org/r/20230808115213.154377-5-wangzhu9@huawei.com
Link: https://lore.kernel.org/r/20230808115213.154377-6-wangzhu9@huawei.com
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: nct3018y: Convert to .probe_new()

The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221021130706.178687-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: Add NCT3018Y real time clock driver

Add real time clock support for NCT3018Y.

Signed-off-by: Mia Lin <mimi05633@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220713090647.8028-4-mimi05633@gmail.com