cyapa_gen3_csum
csum = cyapa_gen3_csum(&fw->data[2], CYAPA_FW_HDR_SIZE - 2);
csum = cyapa_gen3_csum(&fw->data[CYAPA_FW_HDR_SIZE],
write_block_cmd.block_checksum = cyapa_gen3_csum(
write_block_cmd.cmd_checksum = cyapa_gen3_csum((u8 *)&write_block_cmd,