rtc: imxdi: 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 ignored (apart
from emitting a warning) 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. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

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/20231002080529.2535610-10-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: imxdi: Mark driver struct with __refdata to prevent section mismatch warning

As described in the added code comment, a reference to .exit.text is ok
for drivers registered via module_platform_driver_probe(). Make this
explicit to prevent a section mismatch warning.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231002080529.2535610-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: imxdi: add wakeup support

The DryIce-based RTC supports alarms that trigger an interrupt.

Configure this interrupt as a wakeup source that wakes the system up
from standby mode.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210511161244.16111-1-martin@kaiser.cx

rtc: imxdi: Convert to a DT-only driver

i.MX has been converted to a DT-only platform, so make the driver
depend on OF, remove the CONFIG_OF ifdefery and remove of_match_ptr().

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210315172029.173250-1-festevam@gmail.com

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: imxdi: fix trivial typos

Fix typos 'pionter' -> 'pointer' and 'softwere' -> 'software'

Signed-off-by: Tales L. da Aparecida <tales.aparecida@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200624012119.54768-1-tales.aparecida@gmail.com

rtc: imxdi: use devm_platform_ioremap_resource() to simplify code

Use the new helper devm_platform_ioremap_resource() which wraps the
platform_get_resource() and devm_ioremap_resource() together, to
simplify the code.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Link: https://lore.kernel.org/r/20190717081411.30622-1-Anson.Huang@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: imxdi: remove unused variable

This variable is no longer used and the compiler rightly complains that
it should be removed.

../drivers/rtc/rtc-imxdi.c: In function ‘dryice_rtc_set_alarm’:
../drivers/rtc/rtc-imxdi.c:633:16: warning: unused variable ‘now’ [-Wunused-variable]
unsigned long now;
^~~

Rework to remove the unused variable.

Fixes: 629d488a3eb6 ("rtc: imxdi: remove unnecessary check")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: imxdi: convert to SPDX identifier

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

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

rtc: imxdi: remove unnecessary check

The RTC core already ensures the alarm is set to a time in the future, it
is not necessary to check again in the driver.

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

rtc: imxdi: use .set_time

Use .set_time instead of the deprecated .set_mmss.

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

rtc: imxdi: switch to rtc_time64_to_tm/rtc_tm_to_time64

Call the 64bit versions of rtc_tm time conversion now that the range is
enforced by the core.

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

rtc: imxdi: set range

The RTC Time Counter MSB Register contains the 32 most significant bits
(47:16) of the 47-bit RTC Time Counter. Clocked by a 32.768 KHz clock, this
register is effectively a 32-bit seconds counter.

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

sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming

So I've noticed a number of instances where it was not obvious from the
code whether ->task_list was for a wait-queue head or a wait-queue entry.

Furthermore, there's a number of wait-queue users where the lists are
not for 'tasks' but other entities (poll tables, etc.), in which case
the 'task_list' name is actively confusing.

To clear this all up, name the wait-queue head and entry list structure
fields unambiguously:

struct wait_queue_head::task_list => ::head
struct wait_queue_entry::task_list => ::entry

For example, this code:

rqw->wait.task_list.next != &wait->task_list

... is was pretty unclear (to me) what it's doing, while now it's written this way:

rqw->wait.head.next != &wait->entry

... which makes it pretty clear that we are iterating a list until we see the head.

Other examples are:

list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
list_for_each_entry(wq, &fence->wait.task_list, task_list) {

... where it's unclear (to me) what we are iterating, and during review it's
hard to tell whether it's trying to walk a wait-queue entry (which would be
a bug), while now it's written as:

list_for_each_entry_safe(pos, next, &x->head, entry) {
list_for_each_entry(wq, &fence->wait.head, entry) {

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

rtc: constify rtc_class_ops structures

Declare rtc_class_ops structures as const as they are only passed
as an argument to the function devm_rtc_device_register. This argument
is of type const struct rtc_class_ops *, so rtc_class_ops structures
having this property can be declared const.
Done using Coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct rtc_class_ops i@p = {...};

@ok1@
identifier r1.i;
position p;
@@
devm_rtc_device_register(...,&i@p,...)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct rtc_class_ops i;

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

rtc: imxdi: use the security violation interrupt

The DryIce chipset has a dedicated security violation interrupt that is
triggered for security violations (if configured to do so). According
to the publicly available imx258 reference manual, irq 56 is used for
this interrupt.

If an irq number is provided for the security violation interrupt,
install the same handler that we're already using for the "normal"
interrupt.

imxdi->irq is used only in the probe function, make it a local variable.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: (trivial) fix a typo

Fix a typo

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: fix spelling mistake in warning message

Minor issue, fix spelling mistake, happend -> happened

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: when locked, do not fail silently

If the DryICE unit is locked it is impossible to set the time. Provide an
error message for this case.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Robert Schwebel <rsc@pengutronix.de>
[rsc: got NDA clearance from Freescale]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: monitor a security violation at runtime

Maybe the unit enters the hardware related state at runtime and not at
system boot time (after a power cycle).

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Robert Schwebel <rsc@pengutronix.de>
[rsc: got NDA clearance from Freescale]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: add the unit recovery code

This code is required to recover the unit from a security violation.
Hopefully this code can recover the unit from a hardware related invalid
state as well.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Robert Schwebel <rsc@pengutronix.de>
[rsc: got NDA clearance from Freescale]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: add some background info about the states the machine can be in

Document the i.MX DryIce machine states.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Robert Schwebel <rsc@pengutronix.de>
[rsc: got NDA clearance from Freescale]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

rtc: imxdi: avoid the __raw* register access functions

Be independent of the endianness of the kernel.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-imxdi.c: add more known register bits

Intended for monitoring and controlling the security features. These bits
are required to bring this unit back to live after a security violation
event was detected. The code to bring it back to live will follow after a
vendor clearance.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
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-imxdi.c: trivial clean up code

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
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: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/rtc/rtc-imxdi.c: check the return value from clk_prepare_enable()

clk_prepare_enable() may fail, so let's check its return value and
propagate it in the case of error.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: simplify devm_request_mem_region/devm_ioremap

Convert the composition of devm_request_mem_region and devm_ioremap to a
single call to devm_ioremap_resource. The associated call to
platform_get_resource is also simplified and moved next to the new call
to devm_ioremap_resource.

This was done using a combination of the semantic patches
devm_ioremap_resource.cocci and devm_request_and_ioremap.cocci, found in
the scripts/coccinelle/api directory.

In rtc-lpc32xx.c and rtc-mv.c, the local variable size is no longer needed.

In rtc-ds1511.c the size field of the local structure is not useful any
more, and is deleted.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-imxdi: 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-imxdi: use module_platform_driver_probe()

Use module_platform_driver_probe() macro which makes the code smaller and
simpler.

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-imxdi: add __init/__exit annotation

When platform_driver_probe() is used, bind/unbind via sysfs is disabled.
Thus, __init/__exit annotations can be added to probe()/remove().

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-imxdi: use devm_clk_get()

Use devm_clk_get() to make cleanup paths more simple.

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>

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>

drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h>

Add the missing header include for spinlocks, to avoid potential build
failures on specific architectures or configurations.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-imxdi.c: add devicetree support

Add device tree support to the rtc-imxdi driver.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-imxdi.c: add missing spin lock initialization

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Roland Stigge <stigge@antcom.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Roland Stigge <stigge@antcom.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: imx dryice: Add missing clk_prepare

prepare the clock before enabling it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers/rtc/rtc-imxdi.c needs linux/sched.h

Include linux/sched.h to fix below build error.

CC drivers/rtc/rtc-imxdi.o
drivers/rtc/rtc-imxdi.c: In function 'di_write_wait':
drivers/rtc/rtc-imxdi.c:168: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)
drivers/rtc/rtc-imxdi.c:168: error: (Each undeclared identifier is reported only once
drivers/rtc/rtc-imxdi.c:168: error: for each function it appears in.)
drivers/rtc/rtc-imxdi.c:168: error: implicit declaration of function 'signal_pending'
drivers/rtc/rtc-imxdi.c:168: error: implicit declaration of function 'schedule_timeout'
drivers/rtc/rtc-imxdi.c: In function 'dryice_norm_irq':
drivers/rtc/rtc-imxdi.c:329: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Wan ZongShun <mcuos.com@gmail.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>

rtc: driver for the DryIce block found in i.MX25 chips

This driver is based on code from Freescale which accompanies their i.MX25
PDK board, with some cleanup.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Sascha Hauer <kernel@pengutronix.de>
Acked-by: Wan ZongShun <mcuos.com@gmail.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>