This PR makes `event_timeout` and `event_timeout_ztimer` two distinct
pseudomodules, where the only api difference is in the init function.
If only `event_timeout_ztimer` is selected then no default ZTIMER
backend is selected and the old init function is not implemented.
If only `event_timeout` is selected then `xtimer` is used unless
`ztimer_usec` is included. In which case the `xtimer` wrapper on top
of `ztimer` is used and `xtimer` is not directly selected. This
allows for the legacy api to be supported with `ztimer_usec` as
a drop-in replacement.
If `event_timeout` and `event_timeut_ztimer` are selected then
`event_timeout` SRC file is excluded from compilation.
This API change refactors the usbdev API to supply buffers via the
usbdev_ep_xmit function. This changes from the usbdev_ep_ready call to allow
separate buffers per call. An usbdev_ep_buf_t pseudotype is available and must
be used when defining buffers used for endpoints to adhere to the DMA alignment
restrictions often required with usb peripherals.
Main advantage is that the usbdev peripherals no longer have to allocate
oversized buffers for the endpoint data, potentially saving multiple KiB
of unused buffer space. These allocations are now the responsibility of
the individual USB interfaces in the firmware
This API change refactors the usbdev API to supply buffers via the
usbdev_ep_xmit function. This changes from the usbdev_ep_ready call to allow
separate buffers per call. An usbdev_ep_buf_t pseudotype is available and must
be used when defining buffers used for endpoints to adhere to the DMA alignment
restrictions often required with usb peripherals.
Main advantage is that the usbdev peripherals no longer have to allocate
oversized buffers for the endpoint data, potentially saving multiple KiB
of unused buffer space. These allocations are now the responsibility of
the individual USB interfaces in the firmware
