#ifndef PARALLEL_NAND_GAS_H
#define PARALLEL_NAND_GAS_H

#include "parallel_nand.h"

#ifdef __cplusplus
extern "C" {
#endif

#define PNAND_GAS_DEFAULT_BASE       0xE000U
#define PNAND_GAS_REGION_REGS        0x0520U
#define PNAND_GAS_DATA_OFFSET        0x0100U
#define PNAND_GAS_DATA_REGS          1024U
#define PNAND_GAS_OOB_OFFSET         0x0500U
#define PNAND_GAS_OOB_REGS             32U

enum {
    PNAND_GAS_REG_SIGNATURE = 0x0000,
    PNAND_GAS_REG_VERSION = 0x0001,
    PNAND_GAS_REG_STATUS = 0x0002,
    PNAND_GAS_REG_ERROR = 0x0003,
    PNAND_GAS_REG_COMMAND = 0x0004,
    PNAND_GAS_REG_PAGE_LO = 0x0005,
    PNAND_GAS_REG_PAGE_HI = 0x0006,
    PNAND_GAS_REG_PAGE_MAIN = 0x0007,
    PNAND_GAS_REG_PAGE_OOB = 0x0008,
    PNAND_GAS_REG_PAGES_PER_BLOCK = 0x0009,
    PNAND_GAS_REG_BLOCKS = 0x000A,
    PNAND_GAS_REG_MANUFACTURER_ID = 0x000B,
    PNAND_GAS_REG_DEVICE_ID = 0x000C,
    PNAND_GAS_REG_BAD_BLOCK = 0x000D,
    PNAND_GAS_REG_GENERATION_LO = 0x000E,
    PNAND_GAS_REG_GENERATION_HI = 0x000F
};

enum {
    PNAND_GAS_CMD_NONE = 0,
    PNAND_GAS_CMD_RESET = 1,
    PNAND_GAS_CMD_READ_ID = 2,
    PNAND_GAS_CMD_READ_PAGE = 3
};

#define PNAND_GAS_STATUS_READY       0x0001U
#define PNAND_GAS_STATUS_BUSY        0x0002U
#define PNAND_GAS_STATUS_PAGE_VALID  0x0004U
#define PNAND_GAS_STATUS_BAD_BLOCK   0x0008U
#define PNAND_GAS_STATUS_ERROR       0x8000U

typedef struct {
    parallel_nand_t *nand;
    unsigned int base;
    unsigned int status;
    int error;
    unsigned long selected_page;
    unsigned long generation;
    unsigned long cached_block;
    int cached_bad_block;
    int block_cache_valid;
    pnand_octet_t id[8];
    pnand_octet_t main_data[PNAND_MT29F1G08_PAGE_MAIN];
    pnand_octet_t oob[PNAND_MT29F1G08_PAGE_OOB];
} parallel_nand_gas_t;

void parallel_nand_gas_init(parallel_nand_gas_t *gas,
                            parallel_nand_t *nand, unsigned int base);

/* Portable GAS callbacks. Values and addresses are exactly 16 bits on wire. */
typedef enum {
    PNAND_GAS_OK = 0,
    PNAND_GAS_NO_REG,
    PNAND_GAS_READ_ONLY,
    PNAND_GAS_REJECTED
} parallel_nand_gas_result_t;

parallel_nand_gas_result_t parallel_nand_gas_read(
    parallel_nand_gas_t *gas, unsigned int address, unsigned int *value);
parallel_nand_gas_result_t parallel_nand_gas_write(
    parallel_nand_gas_t *gas, unsigned int address, unsigned int value);

#ifdef __cplusplus
}
#endif

#endif