usb: musb: tracing: Use the new __vstring() helper

Instead of open coding a __dynamic_array() with a fixed length (which
defeats the purpose of the dynamic array in the first place). Use the new
__vstring() helper that will use a va_list and only write enough of the
string into the ring buffer that is needed.

Link: https://lkml.kernel.org/r/20220705224750.532345354@goodmis.org

Cc: Bin Liu <b-liu@ti.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

usb: musb: Implement tracing for state change events

The devctl register on musb is the only way to get state information
on musb. The hardware can easily get confused because it tries to do
things on it's own automagically, and things like slow VBUS rise can
make things fail.

Let's make it easier to debug the ongoing state change issues that
keep popping up on regular basis and add tracing support.

With these changes we can easily trace musb state change events with:

echo 1 > /sys/kernel/debug/tracing/events/musb/musb_state/enable
cat /sys/kernel/debug/tracing/trace_pipe
echo 0 > /sys/kernel/debug/tracing/events/musb/musb_state/enable

Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Andreas Kemnade <andreas@kemnade.info>
Cc: Bhushan Shah <bshah@kde.org>
Cc: Drew Fustini <drew@beagleboard.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210604080536.12185-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: musb: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to USB Dual Role (OTG-ready) Controller Drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Link: https://lore.kernel.org/r/20200404104952.GA6575@nishad
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: musb: fix __iomem in trace functions

The trace functions should have __iomem on the addr
pointers. Add __iomem to avoid the following warnings
from sparse:

drivers/usb/musb/musb_core.c:253:55: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:253:55: expected void const *addr
drivers/usb/musb/musb_core.c:253:55: got void const [noderef] <asn:2> *addr
drivers/usb/musb/musb_core.c:259:56: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:259:56: expected void const *addr
drivers/usb/musb/musb_core.c:259:56: got void [noderef] <asn:2> *addr
drivers/usb/musb/musb_core.c:267:55: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:267:55: expected void const *addr
drivers/usb/musb/musb_core.c:267:55: got void const [noderef] <asn:2> *addr
drivers/usb/musb/musb_core.c:273:56: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:273:56: expected void const *addr
drivers/usb/musb/musb_core.c:273:56: got void [noderef] <asn:2> *addr
drivers/usb/musb/musb_core.c:383:55: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:383:55: expected void const *addr
drivers/usb/musb/musb_core.c:383:55: got void const [noderef] <asn:2> *addr
drivers/usb/musb/musb_core.c:390:56: warning: incorrect type in argument 2 (different address spaces)
drivers/usb/musb/musb_core.c:390:56: expected void const *addr
drivers/usb/musb/musb_core.c:390:56: got void [noderef] <asn:2> *addr

Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200115132547.364-18-b-liu@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: musb: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Acked-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: cppi41: add dma channel tracepoints

Add tracepoints for cppi41 dma channels.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: gadget: add usb-request tracepoints

Add usb_request tracepoints for gadget mode.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: host: add urb tracepoints

Add urb tracepoints for host mode.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: add tracepoints to dump interrupt events

This adds tracepoints to dump musb interrupt events.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: add tracepoints for register access

This adds tracepoints to musb register read/write wrappers to get
trace log for register access.

The default tacepoint log prefix here would be musb_readX/writeX(),
which is not much helpful. So this patch let the tracepoints use
__buildin_return_address(0) to print the caller funciton name to
provide more context of the register access.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: musb: add tracepoints support for debugging

To avoid printk() overhead while debugging, this patch implements the
foundation of tracepoints logging for musb driver to make debug
easier.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>