rtc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230724205456.767430-1-robh@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: k3: handle errors while enabling wake irq

Due to the potential failure of enable_irq_wake(), it would be better to
return error if it fails.

Fixes: b09d633575e5 ("rtc: Introduce ti-k3-rtc")
Cc: Nishanth Menon <nm@ti.com>
Signed-off-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230323085904.957999-1-d-gole@ti.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: k3: Use devm_clk_get_enabled() helper

The devm_clk_get_enabled() helper:
- calls devm_clk_get()
- calls clk_prepare_enable() and registers what is needed in order to
call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code, the error handling paths and avoid the need of
a dedicated function used with devm_add_action_or_reset().

Based on my test with allyesconfig, this reduces the .o size from:
text data bss dec hex filename
12843 4804 64 17711 452f drivers/rtc/rtc-ti-k3.o
down to:
12523 4804 64 17391 43ef drivers/rtc/rtc-ti-k3.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/601288834ab71c0fddde7eedd8cdb8001254ed7e.1661329498.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

rtc: k3: detect SoC to determine erratum fix

To allow new SoCs to use this device without a new compatible string,
use a soc_device_attribute list to define all SoCs affected by the TI
i2327 erratum and require help from their bootloaders to unlock this
device.

Signed-off-by: Bryan Brattlof <bb@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220816173312.23243-2-bb@ti.com

rtc: k3: wait until the unlock field is not zero

After writing the magic words to the KICK0 and KICK1 registers, we must
wait for a 1 in the unlock field of the general control register to
signify when the rtc device is in an unlocked state.

Signed-off-by: Bryan Brattlof <bb@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220816173312.23243-1-bb@ti.com

rtc: Introduce ti-k3-rtc

Introduce support for Texas Instruments Real Time Clock controller on
newer K3 family of SoCs such as AM62x.

The hardware module that is being supported is the "digital only"
version which doesn't have capability of external wakeup sources and
external power backup. However, for many practical applications, this
should suffice as RTC is operational across low power sequences.

The hardware block by itself is split into two distinct domains
internally to further reduce the power consumption with the actual
counter block and comparators clocked off a 32k clock source (which
based on SoC integration can be sourced by an external crystal) and an
register interface block which is driven by the bus clock. While optimal
from power perspective, it does create some complicated synchronizations
and sequences that one must be wary of in the driver handling.

Acked-by: Andrew Davis <afd@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Tested-by: Georgi Vlaev <g-vlaev@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220623170808.20998-3-nm@ti.com