rtc: spear: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230304133028.2135435-32-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: spear: set range max

In the commit f395e1d3b28d7c2c67b73bd467c4fb79523e1c65
("rtc: spear: set range"), the value of
RTC_TIMESTAMP_END_9999 was incorrectly set to range_min.
390 config->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
391 config->rtc->range_max = RTC_TIMESTAMP_END_9999;

Fixes: f395e1d3b28d ("rtc: spear: set range")
Signed-off-by: Zeng Jingxiang <linuszeng@tencent.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220728100101.1906801-1-zengjx95@gmail.com

rtc: spear: fix spear_rtc_read_time

The reference manual doesn't specify whether the registers are latched and
they probably aren't, ensure the read time and date are consistent.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20220309162301.61679-21-alexandre.belloni@bootlin.com

rtc: spear: drop uie_unsupported

Since commitc9f5c7e7a84f ("rtc: rtc-spear: Provide flag for no support of
UIE mode") which was in 2012, the core changed a lot and UIE are now
supported using regular alarms. Drop uie_unsupported now to reflect that.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20220309162301.61679-20-alexandre.belloni@bootlin.com

rtc: spear: set range

While the RTC can store dates from year 0000 to 9999, leap years where not
tested fro 2100. The driver currently stores tm_year directly which will
probably fail at that time or more probably in 2300.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20220309162301.61679-19-alexandre.belloni@bootlin.com

rtc: spear: switch to devm_rtc_allocate_device

Switch to devm_rtc_allocate_device/devm_rtc_register_device, this allows
for further improvement of the driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20220309162301.61679-18-alexandre.belloni@bootlin.com

rtc: spear: convert to SPDX identifier

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

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210707075804.337458-11-nobuhiro1.iwamatsu@toshiba.co.jp

rtc: rtc-spear: replace spin_lock_irqsave by spin_lock in hard IRQ

The code has been in a irq-disabled context since it is hard IRQ. There
is no necessity to do it again.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1615775970-59070-1-git-send-email-tiantao6@hisilicon.com

rtc: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20191006102953.57536-2-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-3-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-4-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-5-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-6-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-7-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-8-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-9-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-10-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-11-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-12-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-13-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-14-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-15-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-16-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-17-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-18-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-19-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-20-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-21-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-22-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-23-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-24-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-25-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-26-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-27-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-28-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-29-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-30-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-31-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-32-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-33-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-34-yuehaibing@huawei.com
Link: https://lore.kernel.org/r/20191006102953.57536-35-yuehaibing@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-rtc@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-40-swboyd@chromium.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: spear: stop validating rtc_time in .set_time and .set_alarm

The RTC core is always validating the rtc_time struct before calling
.set_time or .set_alarm. It is not necessary to do it again.

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

rtc: constify rtc_class_ops structures

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>

rtc: simplify use of devm_ioremap_resource

Remove unneeded error handling on the result of a call to
platform_get_resource when the value is passed to devm_ioremap_resource.

Move the call to platform_get_resource adjacent to the call to
devm_ioremap_resource to make the connection between them more clear.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression pdev,res,n,e,e1;
expression ret != 0;
identifier l;
@@

- res = platform_get_resource(pdev, IORESOURCE_MEM, n);
... when != res
- if (res == NULL) { ... \(goto l;\|return ret;\) }
... when != res
+ res = platform_get_resource(pdev, IORESOURCE_MEM, n);
e = devm_ioremap_resource(e1, res);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[viresh.kumar@linaro.org: acked rtc-spear]
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: rtc-spear: remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they duplicate
the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-spear: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release or
on probe failure, since commit 0998d063100 ("device-core: Ensure drvdata
= NULL when no driver is bound"). Thus, it is not needed to manually
clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-spear: convert spear_rtc_driver to dev_pm_ops

Instead of using legacy suspend/resume methods, using newer dev_pm_ops
structure allows better control over power management.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-spear: use devm_rtc_device_register()

devm_rtc_device_register() is device managed and makes cleanup
paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: Convert to devm_ioremap_resource()

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Drivers: rtc: remove __dev* attributes.

CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rtc: rtc-spear: Provide flag for no support of UIE mode

The applications can set the RTC hardware to trigger interrupts in one
of three modes:
* AIE: Alarm interrupt
* UIE: Update interrupt (ie: once per second)
* PIE: Periodic interrupt (sub-second irqs)

The above defined 3 modes are to be supported in the RTC HW in form of
interrupts. The SPEAr RTC hardware does not support the later two modes.

There have been refinements in the RTC core in mainline related to
use of timer queue infrastructure to manage events in RTC. Please refer
the below mentioned patch for details:
* RTC: Rework RTC code to use timerqueue for events
* SHA ID: 6610e0893b8bc6f59b14fed7f089c5997f035f88

There have been provisions added to support hardware that do not have
support the UIE mode. Please refer the following patch.
* rtc: Provide flag for rtc devices that don't support UIE
* SHA ID: 4a649903f91232d02284d53724b0a45728111767

The patch makes use of the provision defined in the above patch to
update the hardware status of UIE mode.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-spear: Add clk_{un}prepare() support

clk_{un}prepare is mandatory for platforms using common clock framework.
Because for SPEAr we don't do anything in clk_{un}prepare() calls, just
call them once in probe/remove.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-spear: use devm_*() routines

Free the rtc-spear driver from tension of freeing resources :) devm_*
derivatives of multiple routines are used while allocating resources,
which would be freed automatically by kernel.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Deepak Sikri <deepak.sikri@st.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-spear.c: fix several error checks

There are several comparisons of a unsigned int to less than zero int
spear RTC driver. Such a check will always be true. In all these cases a
signed int is assigned to the unsigned variable, which is checked, before.
So the right fix is to make the checked variable signed as well. In one
case the check can be dropped completely, because all it does it returns
'err' if 'err' is less than zero, otherwise it returns 0. Since in this
particular case 'err' is always either 0 or less this is the same as just
returning 'err'.

The issue has been found using the following coccinelle semantic patch:

//<smpl>
@@
type T;
unsigned T i;
@@
(
*i < 0
|
*i >= 0
)
//</smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-spear.c: fix use-after-free in spear_rtc_remove()

`config' is freed and is then used in the rtc_device_unregister() call,
causing a kernel panic.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Reviewed-by: Viresh Kumar <viresh.linux@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/spear: add Device Tree probing capability

SPEAr platforms now support DT and so must convert all drivers support DT.
This patch adds DT probing support for rtc and updates its documentation
too.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Cc: Rob Herring <robherring2@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/rtc-spear: call platform_set_drvdata() before registering rtc device

rtc_device_register() calls rtc-spear routines internally. These
routines call dev_get_drvdata() to get struct spear_rtc_config.
Currently, platform_set_drvdata is called after rtc device is
registered. This causes system to crash, as dev_get_drvdata returns
NULL.

For this we need to call platform_set_drvdata() before registering rtc
device. This requires further cleanup, that leads to removal of
dev_set_drvdata on rtc->dev, which was just not required at all.

Also, we change the parameter to request_irq and pass pointer to config
instead of pointer to rtc struct.

This patch brings all above changes.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Deepak Sikri <deepak.sikri@st.com>
Acked-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/spear: fix for RTC_AIE_ON and RTC_AIE_OFF ioctl errors

Define API for '.alarm_irq_enable' to enable and disable alarm irq. This
is required by the framework else RTC_AIE_ON and RTC_AIE_OFF ioctls
return errors.

Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Deepak Sikri <deepak.sikri@st.com>
Acked-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc-spear: fix for balancing the enable_irq_wake in Power Mgmt

Handle the fix for unbalanced irq for the cases when enable_irq_wake
fails, and a warning related to same is displayed on the console. The
workaround is handled at the driver level.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: convert drivers/rtc/* to use module_platform_driver()

This patch converts the drivers in drivers/rtc/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: John Stultz <john.stultz@linaro.org>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: add support for spear rtc

Signed-off-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>