This patch cleans the following checkpatch complaints:

CHECK: 'initalized' may be misspelled - perhaps 'initialized'?
#644: FILE: drivers/rtc/rtc-stm32.c:644:
+	 * the calendar has been initalized or not. INITS flag is reset by a

CHECK: Alignment should match open parenthesis
#669: FILE: drivers/rtc/rtc-stm32.c:669:
+	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name,
+			&stm32_rtc_ops, THIS_MODULE);
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

nvmem_register() never returns NULL, so IS_ERR is good enough here.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

nvmem_register() assumes these values to be 1 if unset, so they don't
need to be set explicitly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Let the core handle the range.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Switch to devm_rtc_allocate_device/rtc_register_device.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Use the 64-bit version of rtc_time_to_tm in mxc_rtc_read_alarm
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This RTC is a 32-bit second counter.

This also solves an issue where mxc_rtc_set_alarm() can return with the
lock taken.
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
before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

While the year is encoded on 32 bits in SYS_TOYWRITE1i/SYS_TOYREAD1. The
Loongson 1c datasheet states that the range is from 0 to 99.

The current code exceeds this range and seems to be working, I deduce that
the leap year algorithm will fail in 2100.

Anyway, alarm registers only encode the year on 14 bits so with alarm
support, the range will always be limited to 0 to 16383.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The error handling in ls1x_rtc_probe used to release resources but since
it is using devm functions, it only returns a value. Make the code clearer
by returning directly instead of using goto.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

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

Let the core handle offsetting and windowing the RTC range.

The RTC has a 40-bit counter counting at 1024 Hz. So its maximum value is
2^(40-10) - 1. Also, let the core handle the offset instead of coding it in
the callbacks. Keep the default epoch at the beginning of 2009 (this will
fail in 2043).
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The vr41xx RTC is a 48-bit counter counting at 32.768 kHz, giving a maximum
value of 2^(48-15)-1 seconds.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Switch to regmap to simplify handling block read/write.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Return an error when the date is unreliable because the battery is low.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The rx8581_driver forward declaration is useless, remove it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rx8581_get_datetime and rx8581_set_datetime are only used after casting dev
to an i2c_client. Remove that useless indirection.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Let the core handle offsetting and windowing the RTC range.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The rx8581 can support dates from 01/01/2000 to 31/12/2099.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

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

The tps65910 RTC can support dates from 01/01/2000 to 31/12/2099.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Currently, the IRQs are disabled when the rtc driver is removed (e.g. when
shutting down the platform).
This means that the RTC will be unable to power up the platform.
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
before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The ab-b5ze-s3 RTC is storing the year in an 8bit bcd coded register so it
can handle dates from year 2000 to year 2099.
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.

Also, the probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ and register the RTC as late as possible.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Now that the RTC range is properly checked, convert the driver to
rtc_tm_to_time64/rtc_time64_to_tm
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The 88pm80x RTC is storing the time as a 32bit offset from a 32bit counter
so it can handle dates from 0 to U32_MAX.
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
before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

pm80x_rtc_info.calib_work and pm80x_rtc_info.vrtc are never used, remove
them.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

It doesn't make sense to set the RTC to a default value at probe time. Let
the core handle invalid date and time.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The at91rm9200 RTC can support dates from 1900-01-01 00:00:00 to 2099-12-31
23:59:59.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Avoid reporting an error when RTC_NVMEM is not selected.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

According to Devicetree Specification v0.2 document:

"The name of a node should be somewhat generic, reflecting the function
of the device and not its precise programming model."

Do as suggested in the binding example.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

RTC driver should not be aware of the PWR registers offset and bits
position. Furthermore, we can imagine that DBP relative register and bit
mask could change depending on the SoC.
So this patch introduces 2 parameters, dbp_reg and dbp_mask, allowing to
get PWR_CR and PWR_CR_DBP from device tree. And it prepares next RTC
version, backup domain write protection is disabled only if needed.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

RTC driver should not be aware of the PWR registers offset and bits
position. Furthermore, we can imagine that Disable Backup Protection (DBP)
relative register and bit mask could change depending on the SoC. So this
patch moves st,syscfg property from single pwrcfg phandle to pwrcfg
phandle/offset/mask triplet.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

RTC alarm interrupt is active high and already configured by device tree.
So remove IRQF_TRIGGER_RISING from driver.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>