soc/ti: pm33xx: 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>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org> # qcom
Link: https://lore.kernel.org/r/20230925095532.1984344-37-u.kleine-koenig@pengutronix.de
Signed-off-by: Nishanth Menon <nm@ti.com>

soc: ti: pm33xx: Fix refcount leak in am33xx_pm_probe

wkup_m3_ipc_get() takes refcount, which should be freed by
wkup_m3_ipc_put(). Add missing refcount release in the error paths.

Fixes: 5a99ae0092fe ("soc: ti: pm33xx: AM437X: Add rtc_only with ddr in self-refresh support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20230106054022.947529-1-linmq006@gmail.com
Signed-off-by: Nishanth Menon <nm@ti.com>

soc: ti: pm33xx: using pm_runtime_resume_and_get instead of pm_runtime_get_sync

Using pm_runtime_resume_and_get is more appropriate
for simplifing code

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tony Lindgren <tony@aotmide.com>
Link: https://lore.kernel.org/r/20220418063059.2558074-1-chi.minghao@zte.com.cn

soc: ti: pm33xx: Fix some resource leak in the error handling paths of the probe function

'am33xx_pm_rtc_setup()' allocates some resources that must be freed on the
error. Commit 2152fbbd47c0 ("soc: ti: pm33xx: Simplify RTC usage to prepare
to drop platform data") has introduced the use of these resources but has
only updated the remove function.

Fix the error handling path of the probe function now.

Fixes: 2152fbbd47c0 ("soc: ti: pm33xx: Simplify RTC usage to prepare to drop platform data")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

soc: ti: pm33xx: Remove set but unused variable 'ret'

Fixes the following W=1 kernel build warning(s):

drivers/soc/ti/pm33xx.c: In function ‘am33xx_do_sram_idle’:
drivers/soc/ti/pm33xx.c:138:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]

Cc: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

soc: ti: pm33xx: Enable basic PM runtime support for genpd

To prepare for moving to use genpd, let's enable basic PM
runtime support.

Cc: Dave Gerlach <d-gerlach@ti.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Simplify RTC usage to prepare to drop platform data

We must re-enable the RTC module clock enabled in RTC+DDR suspend, and
pm33xx has been using platform data callbacks for that. Looks like for
retention suspend the RTC module clock must not be re-enabled.

To remove the legacy platform data callbacks, and eventually be able to
drop the RTC legacy platform data, let's manage the RTC module clock
and register range directly in pm33xx.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Add base cpuidle support

Some cpuidle C-states supported on am335x and am437x, like C1 on am335x,
require the use of the wkup_m3_ipc driver, and all C-states beyond C0 on
both platforms require the use of the SRAM sleep code.

Pass am33xx_do_sram_idle as the idle function to the platform pm core to
be used by the cpuidle-arm driver when entering cpuidle states.
am33xx_do_sram_idle will detect when the wkup_m3 is needed and ping it
if necessary before calling the final cpu_suspend op which will execute
the SRAM code to put the cpu into idle.

Finally, use the begin_suspend and finish_suspend platform ops to be
called at the beginning and end of suspend path to allow use of
cpu_idle_poll_ctrl.

This prevents races between cpuidle and suspend paths trying to
communicate with the wkup_m3, as during suspend we only want it
configured for entry to suspend.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: pm33xx-core: Extend platform_data ops for cpuidle

In order for am335x and am437x to properly enter deeper c-states in
cpuidle they must always call into the sleep33/43xx suspend code and
also sometimes invoke the wkup_m3_ipc driver. These are both controlled
by the pm33xx module so we must provide a method for the platform code
to call back into the module when it is available as the core cpuidle
ops that are invoked by the cpuidle-arm driver must remain as built in.

Extend the init platform op to take an idle function as an argument so
that we can use this to call into the pm33xx module for c-states that
need it. Also add a deinit op so we can unregister this idle function
from the PM core when the pm33xx module gets unloaded.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Make two symbols static

Fix sparse warnings:

drivers/soc/ti/pm33xx.c:144:27: warning: symbol 'rtc_wake_src' was not declared. Should it be static?
drivers/soc/ti/pm33xx.c:160:5: warning: symbol 'am33xx_rtc_only_idle' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Fix static checker warnings

The patch fixes a bunch of static checker warnings.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Add a print while entering RTC only mode with DDR in self-refresh

Currently there is no way to distinguish if the SoC entered DS0
mode or the RTC only mode. Hence add a print before entering
the RTC only mode.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: AM437X: Add rtc_only with ddr in self-refresh support

During RTC-only suspend, power is lost to the wkup domain, so we need to
save and restore the state of that domain. We also need to store some
information within the RTC registers so that u-boot can do the right thing
at powerup.

The state is entered by getting the RTC to bring the pmic_power_en line low
which will instruct the PMIC to disable the appropriate power rails after
putting DDR into self-refresh mode. To bring pmic_power_en low, we need to
get an ALARM2 event. Since we are running from SRAM at that point, it means
calculating what the next second is (via ASM) and programming that into the
RTC. This patch also adds support for wake up source detection.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: pm33xx: Move the am33xx_push_sram_idle to the top

Move the am33xx_push_sram_idle function to the top as a preparation
for rtc+ddr mode as the function will be called by multiple functions
currently present before it.

No functional changes.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: sleep33/43xx: Add RTC-Mode support

Add support for RTC mode to low level suspend code. This includes
providing the rtc base address for the assembly code to configuring the
PMIC_PWR_EN line late in suspend to enter RTC+DDR mode.

Note: This patch also fold in left out space parameter for
am33xx_emif_sram_table and am43xx_emif_sram_table

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: sleep33/43xx: Make sleep actions configurable

Add an argument to the sleep33xx and sleep43xx code to allow us to set
flags to determine which portions of the code get called in order to use
the same code for multiple power saving modes. This patch allows us to
decide whether or not we flush and disable caches, save EMIF context,
put the memory into self refresh and disable the EMIF, and/or invoke
the wkup_m3 when entering into WFI.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

soc: ti: Add pm33xx driver for basic suspend support

AM335x and AM437x support various low power modes as documented
in section 8.1.4.3 of the AM335x Technical Reference Manual and
section 6.4.3 of the AM437x Technical Reference Manual.

DeepSleep0 mode offers the lowest power mode with limited
wakeup sources without a system reboot and is mapped as
the suspend state in the kernel. In this state, MPU and
PER domains are turned off with the internal RAM held in
retention to facilitate the resume process. As part of
the boot process, the assembly code is copied over to OCMCRAM
so it can be executed to turn of the EMIF and put DDR into self
refresh.

Both platforms have a Cortex-M3 (WKUP_M3) which assists the MPU
in DeepSleep0 entry and exit. WKUP_M3 takes care
of the clockdomain and powerdomain transitions based on the
intended low power state. MPU needs to load the appropriate
WKUP_M3 binary onto the WKUP_M3 memory space before it can
leverage any of the PM features like DeepSleep. This loading
is handled by the remoteproc driver wkup_m3_rproc.

Communication with the WKUP_M3 is handled by a wkup_m3_ipc
driver that exposes the specific PM functionality to be used
the PM code.

In the current implementation when the suspend process
is initiated, MPU interrupts the WKUP_M3 to let it know about
the intent of entering DeepSleep0 and waits for an ACK. When
the ACK is received MPU continues with its suspend process
to suspend all the drivers and then jumps to assembly in
OCMC RAM. The assembly code puts the external RAM in self-refresh
mode, gates the MPU clock, and then finally executes the WFI
instruction. Execution of the WFI instruction with MPU clock gated
triggers another interrupt to the WKUP_M3 which then continues
with the power down sequence wherein the clockdomain and
powerdomain transition takes place. As part of the sleep sequence,
WKUP_M3 unmasks the interrupt lines for the wakeup sources. WFI
execution on WKUP_M3 causes the hardware to disable the main
oscillator of the SoC and from here system remains in sleep state
until a wake source brings the system into resume path.

When a wakeup event occurs, WKUP_M3 starts the power-up
sequence by switching on the power domains and finally
enabling the clock to MPU. Since the MPU gets powered down
as part of the sleep sequence in the resume path ROM code
starts executing. The ROM code detects a wakeup from sleep
and then jumps to the resume location in OCMC which was
populated in one of the IPC registers as part of the suspend
sequence.

Code is based on work by Vaibhav Bedia.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>