GPMC_CS_SIZE
GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * cs;
GPMC_CS_NAND_ADDRESS + GPMC_CS_SIZE * cs;
GPMC_CS_NAND_DATA + GPMC_CS_SIZE * cs;
reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;