power: reset: at91: Drop '__init' from at91_wakeup_status()

When building with clang, there are two section mismatch warnings:

WARNING: modpost: vmlinux: section mismatch in reference: at91_poweroff_probe+0x7c (section: .text) -> at91_wakeup_status (section: .init.text)
WARNING: modpost: vmlinux: section mismatch in reference: at91_shdwc_probe+0xcc (section: .text) -> at91_wakeup_status (section: .init.text)

Drop '__init' from at91_wakeup_status() to clear up the mismatch.

Fixes: dde74a5de817 ("power: reset: at91-sama5d2_shdwc: Stop using module_platform_driver_probe()")
Fixes: 099806de68b7 ("power: reset: at91-poweroff: Stop using module_platform_driver_probe()")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: 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>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Link: https://lore.kernel.org/r/20231105094712.3706799-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: Stop using module_platform_driver_probe()

On today's platforms the benefit of platform_driver_probe() isn't that
relevant any more. It allows to drop some code after booting (or module
loading) for .probe() and discard the .remove() function completely if
the driver is built-in. This typically saves a few 100k.

The downside of platform_driver_probe() is that the driver cannot be
bound and unbound at runtime which is ancient and so slightly
complicates testing. There are also thoughts to deprecate
platform_driver_probe() because it adds some complexity in the driver
core for little gain. Also many drivers don't use it correctly. This
driver for example misses to mark the driver struct with __ref which is
needed to suppress a (W=1) modpost warning.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Link: https://lore.kernel.org/r/20231104211501.3676352-19-u.kleine-koenig@pengutronix.de
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: Convert to devm_platform_ioremap_resource()

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: Remove redundant error printing in at91_shdwc_probe()

When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.

Therefore, remove the error printing here to simplify code and reduce the
binary size.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: add support for sama7g5

Add support for SAMA7G5 by adding proper struct reg_config structure
and since SAMA7G5 is not currently on LPDDR setups the commit also
avoid the mapping of DDR controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-sama5d2_shdwc: fix wkupdbc mask

According to datasheet WKUPDBC mask is b/w bits 26..24.

Fixes: f80cb48843987 ("power: reset: at91-shdwc: add new shutdown controller driver")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: use proper master clock register offset

SAM9X60's PMC uses different offset for master clock register.
Add a member of type struct pmc_reg_config in struct reg_config,
fill it correspondingly for SAMA5D2 and SAM9X60 and use it in
poweroff() function.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: introduce struct shdwc_reg_config

This driver uses AT91_PMC_MCKR in poweroff() function. But the
SAM9X60's PMC versions maps AT91_PMC_MCKR functionality at different
offset compared to the SAMA5D2's one. This patch prepares the field
so that different AT91_PMC_MCKR's offsets to be introduced in
struct reg_config so that proper offset to be used for AT91_PMC_MCKR
based on compatible string.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: lookup for proper PMC DT node

Driver has been enabled also for SAM9X60. At the moment the patch which did
this has been sent to mainline the PMC for SAM9X60 wasn't integrated.
SAM9X60 has a new PMC compatible (see commit 01e2113de9a5
("clk: at91: add sam9x60 pmc driver")). Do to this we have to
look for proper PMC compatible here, in SHDWC driver.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: add support for SAM9X60

Add support for SAM9X60 shutdown controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: add RTT wakeup capability

Add RTT wakeup capability.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

There should be only one instance of struct shdwc in the system. This is
referenced through at91_shdwc. Return in probe if at91_shdwc is already
allocated.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: rename at91_shdwc_base member of struct shdwc

Rename at91_shdwc_base member of struct shdwc to shdwc_base. There is
already an "at91" string in at91_shdwc object.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: make sclk part of struct shdwc

Make sclk part of struct shdwc to have all the data specific to SHDWC
grouped together in one structure.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: make mpddrc_base part of struct shdwc

Make mpddrc_base part of struct shdwc since there is also only one
instance of struct shdwc *at91_shdwc in system and to have all data
specific to SHDWC grouped together.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: use only one poweroff function

Use only one poweroff function for sama5d2 and adapt it to work for both
scenarios (having LPDDR or not).

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: at91-poweroff: switch to slow clock before shutdown

The SAMA5D2 NRST input signal is resynchronized with the SLCK clock and it
can take up to 2 SLCK cycles (about 90us) for the internal reset to be
effective. During this delay, the VDDCORE current consumption may still be
high (application-dependent) with the VDDCORE regulator already OFF. Under
such conditions, VDDCORE may operate below its operating range leading to
potential register corruption.

To prevent such situation, it is recommended to decrease significantly the
power consumption of the device once the voltage regulator is turned-off.
This can be achieved by operating the device at a much lower low frequency.

To solve this switch the master clock to slock clock just before writing
shutdown command to shutdown controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Suggested-by: Patrice Vilchez <patrice.vilchez@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: reset: account for const type of of_device_id.data

This driver creates a const structure that it stores in the data
field of an of_device_id array.

Add const to the declaration of the location that receives a value
from the data field to ensure that the compiler will continue to check
that the value is not modified and remove the const-dropping cast on
the access to the data field.

Done using Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

power: reset: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

power: reset: at91-sama5d2_shdwc: fix clobber list

Assembly in at91_lpddr_poweroff has r0 in the clobber list but uses r6.

Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

power: reset: at91-poweroff: timely shutdown LPDDR memories

LPDDR memories can only handle up to 400 uncontrolled power off. Ensure the
proper power off sequence is used before shutting down the platform.

Cc: <stable@vger.kernel.org> # 4.4+
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

power: reset: at91-shdwc: add new shutdown controller driver

Sama5d2 SoC has a completely new shutdown controller with new features and
register layout. It thus makes sense to add a new driver for this new
peripheral.

This driver is Device Tree only and handles events from the wake-up pin and
the RTC.
As the register layout may change in the future, so some values are encoded
in a configuration structure.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>