soundwire: cadence: add BTP/BRA helpers to format data

The Cadence IP expects a specific format (detailed in the
Documentation). Add helpers to copy the data into the DMA buffer.

The crc8 table is for now only used by the Cadence driver. This table
might be moved to a common module at a later point if needed by other
controller implementations.

Signed-off-by: Pierre-Louis Bossart <[email protected]>
Signed-off-by: Bard Liao <[email protected]>
Reviewed-by: Péter Ujfalusi <[email protected]>
Reviewed-by: Liam Girdwood <[email protected]>
Reviewed-by: Ranjani Sridharan <[email protected]>
Tested-by: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: plbossart

drivers/soundwire/Kconfig

@@ -31,6 +31,7 @@ config SOUNDWIRE_AMD
 
 config SOUNDWIRE_CADENCE
 	tristate
+	select CRC8
 
 config SOUNDWIRE_INTEL
 	tristate "Intel SoundWire Master driver"