commands/*: Replace license and copyright boilerplate by SPDX identfiers ...

While at it also drop references to the non-existing CREDITS file and do
some small rearrangements for some uniform formatting.
(SPDX-License-Identifier first, then copyright texts and then an empty
line.)

The advantage is that these specifiers are machine-parseable which helps
license conformance.

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

usbgadget: autostart: add DFU support ...

Use global variable dfu_function to autostart DFU. As similar code
is used to start multifunction gadget using command, move common
code to common/usbgadget.c and consolidate it.
It turned out that '-s' option of usbgadget command does nothing,
so remove its help text and make it function as '-a'.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usbgadget: Update command help text ...

- Do not use BAREBOX_CMD_HELP_OPT with an empty option to extend the
  previous option text. It confuses the rst converter
- Add a '\t' to the options to align the option help texts in the
  barebox command help

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

fastboot command: Add -b option to export bbu handlers ...

When -b is given the usbgadget command will automatically export the
registered bbu handlers via fastboot.

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

usbgadget command: catch errors when parsing the file list ...

file_list_parse() can fail. Print an error message in this case instead
of crashing.

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

commands: usbgadget: update fastboot help text ...

cmd_usbgadget can use now the fallback to
global.usbgadget.fastboot_function. Update help text to reflect this
behavior.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: usbgadget: provide fallback to global variables ...

usbgadget autostarter is providing now a global variable to configure fastboot.
We can use is as fallback for the cmd_usbgadget as well.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: gadget: properly release f_multi_opts ...

The usbgadget commands uses statically allocated f_multi_opts and passes
this to usb_multi_register(). These f_multi_opts are of course no
longer valid when we leave the usbgadget command. Luckily we do not use
the data after we left the usbgadget command, so this never has been a
problem. However, f_multi_opts has some allocated members which we can
not free anymore on gadget unregistration because we no longer have the
pointer to them.

Fix this by adding a release function to struct f_multi_opts. This way
we can allocate all memory dynamically and properly free it when not
used anymore.

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

commands: usbgadget: Fix -d option help text ...

The -d option disables any currently active gadget, it does not
necessarily have to be a serial gadget.

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

USB: gadget: Add a multi function gadget ...

Similar to the Kernel multi function this gadget driver is used
for creating a USB device with multiple functions. This is
created and removed with the newly created 'usbgadget' command.
Based on the options it creates combinations of DFU, fastboot
and serial USB functions.

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