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.

Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

The core driver should create and manage irq mappings instead of
leaf drivers. This patch change to pass irq domain to
devm_mfd_add_devices() and it will create mapping for irq resources
automatically. And remove irq mapping in rtc driver since this has
been done in core driver.

Signed-off-by: Chen Zhong <chen.zhong@mediatek.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Check for rtc_class_ops structures that are only passed to
devm_rtc_device_register, rtc_device_register,
platform_device_register_data, all of which declare the corresponding
parameter as const.  Declare rtc_class_ops structures that have these
properties as const.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct rtc_class_ops i@p = { ... };

@ok@
identifier r.i;
expression e1,e2,e3,e4;
position p;
@@
(
devm_rtc_device_register(e1,e2,&i@p,e3)
|
rtc_device_register(e1,e2,&i@p,e3)
|
platform_device_register_data(e1,e2,e3,&i@p,e4)
)

@bad@
position p != {r.p,ok.p};
identifier r.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct rtc_class_ops i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The driver uses the MODULE_ALIAS() macro to export a platform module alias
to allow the module to be autoloaded if the device is registered using the
legacy platform registration mechanism but the driver is always used by OF
only machines so the alias is not needed and should just be removed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

These platform drivers have a OF device ID table but the OF module
alias information is not created so module autoloading won't work.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Implement the suspend/resume function in order to control rtc's irq_wake flag and handle as wakeup source.

Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc_sysfs_add_device checks if device can wakeup before creating the
wakealarm file in sysfs. Thus the driver must set wakeup capability
before registering the rtc device.

Signed-off-by: Wei-Ning Huang <wnhuang@google.com>
Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

On some !ARM 32bits platforms, the following compilation error happens
because of the division on a 64bits value in mtk_rtc_read_time():

drivers/built-in.o: In function `mtk_rtc_read_time':
rtc-mt6397.c:(.text+0x265d13f): undefined reference to `__divdi3'
rtc-mt6397.c:(.text+0x265d150): undefined reference to `__moddi3'

Use div_s64() as done in rtc_time64_to_tm() to solve that.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add Mediatek MT6397 RTC driver

Signed-off-by: Tianping Fang <tianping.fang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>