reset_source: introduce reset_source_to_string ...

We have a few places where driver code prints reset_source_name() to
console after setting the reset source.

This working is probe order dependent, because reset_source_name()
prints the highest priority reset_source so far, which doesn't
necessarily have to be the one that was just computed.

Implement reset_source_to_string, so drivers can be migrated to use it.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: implement helper to set a device as reset source ...

This allows to remove some boilerplate from drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: drop reset_source_set_instance() ...

The semantic of reset_source_set_instance() required a separate call to
reset_source_set() (or reset_source_set_priority()) and checked right
usage only using the type. Make the set of functions a bit easier to use
by dropping reset_source_set_instance() and instead introduce a function
that can set all relevant parameters (source, priority and instance) in
one go.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: fix ordering of exported functions ...

Declare and implement getters first, then setters. This syncs the order
of functions in reset_source.c and reset_source.h.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: use instance = -1 as default ...

As with platform device id (does someone still remember?) 0 might be a
valid id. So use -1 for "unknown" or "doesn't apply" instead of 0.

Also don't pass the instance to the device tree if negative. (This ends
up as 0xffffffff otherwise.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: add new Brownout reset (BOR) source ...

The STM32MP1 can report brown out as reason for a reset,
which doesn't fit into existing reasons. Thus add a new
one to the enumeration.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: reset_source: Introduce reset_source_name() ...

Introduce reset_source_name() to get string representation of current
reset source.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: reset_source: Add the notion of "reset source instance" ...

In order to accomodate SoCs that come with multiple watchdogs (or any
other reset sources of the same kind) add a notion of "reset source
instance", similar to what we already have for bootsource API.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Revert "globalvar: make globalvar functions more consistent" ...

This reverts commit 1b4a05c.

globalvar: make globalvar functions more consistent ...

Similar to the device parameter functions also make the globalvar
functions more consistent. This also adds support for readonly
globalvars and changes several existing globalvars which should
really be readonly to readonly.

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

reset_source: export reset_source_set_priority ...

In commit 4a7534bf07e ("reset-source: Allow different priorities") the
function name changed from reset_source_set to reset_source_set_priority.
Do that change in EXPORT_SYMBOL() accordingly.
reset_source_set still exists but is a static inline now.

Fixes: 4a7534bf07e ("reset-source: Allow different priorities")
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset-source: Add some debugging aids ...

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

reset-source: Allow different priorities ...

Different devices may report the reset source with different levels
of certainty. For example a SoC may see a power-on reset, but this
may only be because an external PMIC has power cycled the SoC. This
means the PMIC knows the real reason better and thus the reset reason
from the PMIC should be preferred.

This patch introduces priorities for the reset_source to handle the
above scenario. Also add a of_get_reset_source_priority() function
to retrieve the desired priority from the device tree.

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

reset-source: Use globalvar_add_simple_enum ...

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

reset_source: Add external reset ...

Some SoCs have special device pins for external reset signals.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: make safe to call earlier ...

reset_source_init used to set the reset source to unknown in a
coredevice_initcall. This means if reset_source_set() has been called
earlier the value would have been overwritten. Fix this by calling
globalvar_add_simple() each time reset_source_set() is called.

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

reset_source: add thermal reset ...

Some SoCs are able to detect if they got reset
in response to an overtemperature event.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: add reset_source_get ...

To get reset_source from C code, not only from shell.

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

reset_source: rename set_reset_source to reset_source_set ...

To get all reset source related functions into the same function
namespace.

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

globalvar: Allow to set initial value ...

Calling globalvar_add_simple() and setting a value is more than common.
Add a parameter for the initial value.

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

Enable a way to provide the reason for "being here" ...

Many architectures support a way to detect why the bootloader is running.
This patch adds a global variable to be able to use the cause in some kind of
shell code to do special things on demand. For example to do an emergency boot,
when the last boot fails and the watchdog reactivate the hanging system.

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