One limitation of the current IPM API is that it is assuming that the
hardware is only exporting one single channel through which the data can
be sent or signalling can happen.
If the hardware supports multiple channels, the IPM device must be
instantiated (possibly in the DT) several times, one for each channel to
be able to send data through multiple channels using the same hw
peripheral. Also in the current IPM API only one callback can be
registered, that means that only one driver is controlling all the
signalling happening on all the channels.
This patch is introducing a new MBOX API that is supporting
multi-channel signalling and data exachange leveraging and extending the
previous (and outdated) IPM API.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
1976f33e87