Cannot test an unsigned variable to be less than 0, it will always fail.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Stefan Roese <stefan.roese@mailbox.org>

Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass <sjg@chromium.org>

Drop all duplicate newlines. No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Add optional support for using old DDR3 training code from 2017.

The code lives in drivers/ddr/marvell/a38x/old/. To prevent symbol
clashing with new DDR3 training code, a special header which renames all
clashing symbols via macros is included and the symbols are prefixed
with 'old_'.

If old DDR3 training support is selected for a board, then the SPL
initialization code calls a new function
  board_use_old_ddr3_training()
to check whether it should use old DDR3 training code. The default
weak implementation returns false, defaulting to new DDR3 training code.

Boards that wish to support this need to select the
  ARMADA_38X_SUPPORT_OLD_DDR3_TRAINING
config option and implement the old version of DDR topology provider,
ddr3_get_topology_map().

Signed-off-by: Marek Behún <kabel@kernel.org>

Backport the option to compile with immutable debug settings also to
the old implementation of the DDR3 training code.

The original PR for mv-ddr-marvell can be seen at
  https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell/pull/45/

Signed-off-by: Marek Behún <kabel@kernel.org>

Fix some compilation warning in the old DDR training code.

Signed-off-by: Marek Behún <kabel@kernel.org>

Import DDR training code from commit 1b69ce2fc0ec ("arm: mvebu:
ddr3_debug: remove self assignments") into
drivers/ddr/marvell/a38x/old/. The code is not used yet.

Explanation:

Since 2019, on some Turris Omnia boards we have been having problems
with newer versions of Marvell's DDR3 training code for Armada 38x,
which is ported from mv-ddr-marvell [1] to U-Boot into the
drivers/ddr/marvell/a38x/ directory:
- sometimes the DDR3 training fails on some older boards, sometime it
  fails on some newer boards
- other times it succeeds, but some boards experience crashes of the
  operating system after running for some time.

Using the stock version of Turris Omnia's U-Boot from solved these
issues, but this solution was not satisfactory, since we wanted
features from new U-Boot.

Back in 2020-2022 we have spent several months trying to debug the
issues, working with Marvell, on our own, and also with U-Boot
community, but these issues persist still.

One solution we used back in 2019 was a "hybrid U-Boot": the SPL part
(containing the DDR3 training code) was taken from the stock version,
while the proper part was current U-Boot at the time. This solution also
has its drawbacks, of which the main one is the need to glue binaries
from two separate builds.

Since then there have been some more changes to the DDR3 training code
in upstream mv-ddr-marvell that have been ported to U-Boot. We have
provided our users experimental builds of U-Boot in the TurrisOS so that
they could try upgrading the firmware and let us know if those problems
still exist. And they do.

We do not have the time nor manpower to debug this problem and fix it
properly. Marvell was also no able to provide a solution to this,
probably because they do not have the manpower as well.

I have therefore come up with this "not that pretty" solution: take the
DDR3 training code from an older version of U-Boot that is known to
work, put it into current U-Boot under old/ subdirectory within
drivers/ddr/marvell/a38x/, build into the SPL binary both the old and
new versions and make it possible to select the old version via an env
variable.

[1] https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell

Signed-off-by: Marek Behún <kabel@kernel.org>

Allow compiling with immutable debug settings:
- DEBUG_LEVEL is always set to DEBUG_LEVEL_ERROR
- register dumps are disabled

This can save around 10 KiB of space in the resulting binary, which is a
lot in U-Boot SPL.

Signed-off-by: Marek Behún <kabel@kernel.org>

The variables is_validate_window_per_if, is_validate_window_per_pup,
sweep_cnt and is_run_leveling_sweep_tests are only used if
DDR_VIEWER_TOOL macro is defined, so define them only in that case.

Make them static since they are only used in ddr3_debug.c.

Signed-off-by: Marek Behún <kabel@kernel.org>

The variables is_default_centralization, is_tune_result and
is_bist_reset_bit are never used.

Signed-off-by: Marek Behún <kabel@kernel.org>