Driver APIs might not implement all operations, making it possible for
a user thread to get the kernel to execute a function at 0x00000000.
Perform runtime checks in all the driver handlers, checking if they're
capable of performing the requested operation.
Fixes#6907.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
As per current policy of requiring supervisor mode to register
callbacks, dma_config() is omitted.
A note added about checking the channel ID for start/stop, current
implementations already do this but best make it explicitly
documented.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Leandro Pereira