When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

According to the documentation the EFI log category is called LOGC_EFI.
All other categories start with LOGC_. So let's fix it.

Fixes: 1973b381a1b3 ("log: add category LOGC_EFI")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

The EFI implementation does not fit into any of the existing categories.

Provide LOGC_EFI so that EFI related message can be filtered.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

When functions return an error it propagates up the stack to the point
where it is reported. Often the error code provides enough information
about the root cause of the error that this is obvious what went wrong.

However in some cases the error may be hard to trace. For example if a
driver uses several devices to perform an operation, it may not be
obvious which one failed.

Add a log_ret() macro to help with this. This can be used to wrap any
error-return value. The logging system will then output a log record when
the original error is generated, making it easy to trace the call stack
of the error.

This macro can significantly impact code size, so its use is controlled
by a Kconfig option, which is enabled for sandbox.

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

It is useful to be able to control the output format of log records on the
console. As a starting point, add definitions for controlling which
elements of the log record are displayed. Use function and message as the
default, since these are the most useful fields.

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

Category and level both use an enum for their ID values. Add functions to
convert these IDs to strings and vice versa. This will allow the log to
output the strings instead of the (inscrutable) values.

At the same time, add a new 'driver-model' category, to cover core
driver-model functions and fix an incorrect value for LOGL_MAX.

Tests will be added with the new 'log' subcommands.

Signed-off-by: Simon Glass <sjg@chromium.org>
(Updated to correct clang warnings)

Add a command which exercises the logging system.

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

Add the logging header file and implementation with some configuration
options to control it.

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

Before adding new features, move these definitions to a separate header
to avoid further cluttering common.h.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>