The TPIU supports serializing the data stream both using an UART-like NRZ
protocol as well as using Manchester encoding. Using Manchester encoding
has the advantage that it enables receivers that support it to recover the
clock from the SWO signal itself. This is particularly useful in situations
where the clock rate changes dynamically or is unknown (for example when
debugging the clock tree setup or working with a device with a misbehaving
main oscillator).
Add a Kconfig choice to switch the protocol, keeping the current default of
using the NRZ encoding.
Signed-off-by: Florian Larysch <larysch@fixme.gmbh>
The `LOG_BACKEND_FORMAT_TIMESTAMP` Kconfig currently depends on
a list of hardcoded backends.
Let's modify it to depend on an intermediary Kconfig
`LOG_BACKEND_SUPPORTS_FORMAT_TIMESTAMP` instead, which can be
selected by a OOT log backend.
Updated all exisitng supported backends to select this new
Kconfig.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
SWO reference frequency was set based on `swo-ref-frequency` under `itm`
nodelabel or `/cpus/cpu@0/clock-frequency` property. Not all platforms
configure those.
All ST devices configure CPU frequency in `clock-frequency` under `rcc`
nodelabel. Configuring the same value for each board in
`/cpus/cpu@0/clock-frequency` would be one way to make SWO work out of the
box. There is lots of copy-pasting involved in this, which makes this very
error-prone.
Introduce Kconfig option, which will default to values configured in `itm`
or `/cpus/cpu@0`. The main advantage will be for platforms like ST, where
CPU clock frequency is already configured in another place. Thsoe could
override default value in SoC, board or any other platform specific layer.
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
This is mainly to reduce clutter in `subsys/logging`, but also to make
backend management slightly easier.
Signed-off-by: Christopher Friedt <cfriedt@fb.com>
